Vadose zone characterization project at the Hanford Tank Farms: BY Tank Farm report

International Nuclear Information System (INIS)

Kos, S.E.

1997-02-01

The US Department of Energy Grand Junction Office (GJO) was tasked by the DOE Richland Operations Office (DOE-RL) to perform a baseline characterization of the contamination distributed in the vadoze zone sediment beneath and around the single-shell tanks (SSTs) at the Hanford Site. The intent of this characterization is to determine the nature and extent of the contamination, to identify contamination sources, and to develop a baseline of the contamination distribution that will permit future data comparisons. This characterization work also allows an initial assessment of the impacts of the vadose zone contamination as required by the Resource Conservation and Recovery Act (RCRA). This characterization project involves acquiring information about the vadose zone contamination with borehole geophysical logging methods and documenting that information in a series of reports. Data from boreholes surrounding each tank are compiled into individual Tank Summary Data Reports. The data from each tank farm are then compiled and summarized in a Tank Farm Report. This document is the Tank Farm Report for the BY Tank Farm

Vadose zone characterization project at the Hanford Tank Farms: BY Tank Farm report

Energy Technology Data Exchange (ETDEWEB)

Kos, S.E.

1997-02-01

The US Department of Energy Grand Junction Office (GJO) was tasked by the DOE Richland Operations Office (DOE-RL) to perform a baseline characterization of the contamination distributed in the vadoze zone sediment beneath and around the single-shell tanks (SSTs) at the Hanford Site. The intent of this characterization is to determine the nature and extent of the contamination, to identify contamination sources, and to develop a baseline of the contamination distribution that will permit future data comparisons. This characterization work also allows an initial assessment of the impacts of the vadose zone contamination as required by the Resource Conservation and Recovery Act (RCRA). This characterization project involves acquiring information about the vadose zone contamination with borehole geophysical logging methods and documenting that information in a series of reports. Data from boreholes surrounding each tank are compiled into individual Tank Summary Data Reports. The data from each tank farm are then compiled and summarized in a Tank Farm Report. This document is the Tank Farm Report for the BY Tank Farm.

Characterization of Vadose Zone Sediment: Borehole 299-E33-46 Near Tank B-110 in the B-BX-BY Waste Management Area

International Nuclear Information System (INIS)

Serne, R JEFFREY.; Bjornstad, Bruce N.; Gee, Glendon W.; Schaef, Herbert T.; Lanigan, David C.; Mccain, Richard G.; Lindenmeier, Clark W.; Orr, Robert D.; Legore, Virginia L.; Clayton, Ray E.; Lindberg, Michael J.; Kutnyakov, Igor V.; Baum, Steven R.; Geiszler, Keith N.; Valenta, Michelle M.; Vickerman, Tanya S.; Royack, Lisa J.

2002-01-01

This report presents vadose sediment characterization data that improves understanding of the nature and extent of past releases in the B tank farm. A vertical borehole, located approximately 15 ft (5 m) from the northeast edge of single-shell tank 241-B-110 was drilled to a total depth of 264.4 ft bgs, the groundwater table was encountered at 255.8 ft bgs. During drilling, a total of 3 two-ft long, 4-inch diameter split-spoon core samples were collected between 10 and 254 ft bgs-an average of every 7.5 ft. Grab samples were collected between these core sample intervals to yield near continuous samples to a depth of 78.3 m (257 ft). Geologic logging occurred after each core segment was emptied into an open plastic container, followed by photographing and sub-sampling for physical and chemical characterization. In addition, 54 out of a total of 120 composite grab samples were opened, sub-sampled, logged, and photographed. Immediately following the geologic examination, the core an d selected grab samples were sub-sampled for moisture content, gamma-emission radiocounting, tritium and strontium-90 determinations, total carbon and inorganic carbon content, and 8 M nitric acid extracts (which provide a measure of the total leachable sediment content of contaminants) and one-to-one sediment to water extracts (which provide soil pH, electrical conductivity, cation, and anion data and water soluble contaminant data). Later, additional aliquots of selected sleeves or grab samples were removed to measure particle size distribution and mineralogy and to squeeze porewater. Major conclusions follow. Vadose zone contamination levels were lower than generally anticipated prior to the initiation of the field investigation. Strong evidence of extensive vadose zone lateral migration in WMA BBXBY exists. There are indications that such lateral migration may have extended into WMA B-BX-BY from adjacent past practice discharge sites. Ponding of runoff from natural precipitation in the

Understanding Fluid and Contaminant Movement in the Unsaturated Zone Using the INEEL Vadose Zone Monitoring System

International Nuclear Information System (INIS)

Hubbell, J. M.; Mattson, E. D.; Sisson, J. B.; Magnuson, S. O.

2002-01-01

DOE has hundreds of contaminated facilities and waste sites requiring cleanup and/or long-term monitoring. These contaminated sites reside in unsaturated soils (i.e. the vadose zone) above the water table. Some of these sites will require active remediation activities or removal while other sites will be placed under institutional controls. In either case, evaluating the effectiveness of the remediation strategy or institutional controls will require monitoring. Classical monitoring strategies implemented at RCRA/CERCLA sites require ground water sampling for 30 years following closure. The overall effectiveness of ground water sampling is diminished due to the fact that by the time you detect chemical transport from a waste site, a major contamination plume likely exists in the vadose zone and the aquifer. This paper suggests a more effective monitoring strategy through monitoring near the contaminant sites within the vadose zone. Vadose zone monitoring allows for quicker detection of potential contaminant transport. The INEEL Vadose Zone Monitoring System (VZMS) is becoming an accepted, cost effective monitoring technology for assessing contaminant transport at DOE facilities. This paper describes the technologies employed in the VZMS and describes how it was used at several DOE facilities. The INEEL VZMS has provided the information in developing and validating both conceptual and risk assessment models of contaminant transport at the Idaho National Engineering and Environmental Laboratory (INEEL), Oak Ridge National Laboratory (ORNL), Savannah River Site (SRS) and the Hanford site. These DOE sites exhibit a broad range of meteorologic, hydrologic and geologic conditions representative of various common geologic environments. The VZMS is comprised of advanced tensiometers, water content sensors, temperature sensors and soil and gas samplers. These instruments are placed at multiple depths in boreholes and allows for the detection of water movement in the

Karst system vadose zone hydrodynamics highlighted by an integrative geophysical and hydrogeological monitoring

Science.gov (United States)

Watlet, A.; Van Camp, M. J.; Francis, O.; Poulain, A.; Hallet, V.; Rochez, G.; Kaufmann, O.

2015-12-01

The vadose zone of karst systems plays an important role on the water dynamics. In particular, temporary perched aquifers can appear in the subsurface due to changes of climate conditions, diminished evapotranspiration and differences of porosity relative to deeper layers. It is therefore crucial, but challenging, to separate the hydrological signature of the vadose zone from the one of the saturated zone for understanding hydrological processes that occur in the vadose zone. Although many difficulties are usually encountered when studying karst environments due to their heterogeneities, cave systems offer an outstanding opportunity to investigate vadose zone from the inside with various techniques. We present results covering two years of hydrogeological and geophysical monitoring at the Rochefort Cave Laboratory (RCL), located in the Variscan fold-and-thrust belt (Belgium), a region that shows many karstic networks within Devonian limestone units. Hydrogeological data such as flows and levels monitoring or tracer tests performed in both vadose and saturated zones bring valuable information on the hydrological context of the studied area. Combining those results with geophysical measurements allows validating and imaging them with more integrative techniques. A microgravimetric monitoring involves a superconducting gravimeter continuously measuring at the surface of the RCL. Early in 2015, a second relative gravimeter was installed in the underlying cave system located 35 meters below the surface. This set up allows highlighting vadose gravity changes. These relative measurements are calibrated using an absolute gravimeter. 12 additional stations (7 at the surface, 5 in the cave) are monitored on a monthly basis by a spring gravimeter. To complete these gravimetric measurements, the site has been equipped with a permanent Electrical Resistivity Tomography (ERT) monitoring system comprising an uncommon array of surface, borehole and cave electrodes. Although such

Advanced Vadose Zone Simulations Using TOUGH

Energy Technology Data Exchange (ETDEWEB)

Finsterle, S.; Doughty, C.; Kowalsky, M.B.; Moridis, G.J.; Pan,L.; Xu, T.; Zhang, Y.; Pruess, K.

2007-02-01

The vadose zone can be characterized as a complex subsurfacesystem in which intricate physical and biogeochemical processes occur inresponse to a variety of natural forcings and human activities. Thismakes it difficult to describe, understand, and predict the behavior ofthis specific subsurface system. The TOUGH nonisothermal multiphase flowsimulators are well-suited to perform advanced vadose zone studies. Theconceptual models underlying the TOUGH simulators are capable ofrepresenting features specific to the vadose zone, and of addressing avariety of coupled phenomena. Moreover, the simulators are integratedinto software tools that enable advanced data analysis, optimization, andsystem-level modeling. We discuss fundamental and computationalchallenges in simulating vadose zone processes, review recent advances inmodeling such systems, and demonstrate some capabilities of the TOUGHsuite of codes using illustrative examples.

Vadose zone monitoring plan using geophysical nuclear logging for radionuclides discharged to Hanford liquid waste disposal facilities

International Nuclear Information System (INIS)

Price, R.K.

1995-11-01

During plutonium production at Hanford, large quantities of hazardous and radioactive liquid effluent waste have been discharged to the subsurface (vadose zone). These discharges at over 330 liquid effluent disposal facilities (ie. cribs, ditches, and ponds) account for over 3,000,000 curies of radioactive waste released into the subsurface. It is estimated that 10% of the contaminants have reached the groundwater in many places. Continuing migration may further impact groundwater quality in the future. Through the RCRA Operational Monitoring Program, a Radionuclide Logging System (RLS) has been obtained by Hanford Technical Services (HTS) and enhanced to measure the distribution of contaminants and monitor radionuclide movement in existing groundwater and vadose zone boreholes. Approximately 100 wells are logged by HTS each year in this program. In some cases, movement has been observed years after discharges were terminated. A similar program is in place to monitor the vadose zone at the Tank Farms. This monitoring plan describes Hanford Programs for monitoring the movement of radioactive contamination in the vadose zone. Program background, drivers, and strategy are presented. The objective of this program is to ensure that DOE-RL is aware of any migration of contaminants in the vadose zone, such that groundwater can be protected and early actions can be taken as needed

Vadose zone transport field study: Detailed test plan for simulated leak tests

International Nuclear Information System (INIS)

AL Ward; GW Gee

2000-01-01

The US Department of Energy (DOE) Groundwater/Vadose Zone Integration Project Science and Technology initiative was created in FY 1999 to reduce the uncertainty associated with vadose zone transport processes beneath waste sites at DOE's Hanford Site near Richland, Washington. This information is needed not only to evaluate the risks from transport, but also to support the adoption of measures for minimizing impacts to the groundwater and surrounding environment. The principal uncertainties in vadose zone transport are the current distribution of source contaminants and the natural heterogeneity of the soil in which the contaminants reside. Oversimplified conceptual models resulting from these uncertainties and limited use of hydrologic characterization and monitoring technologies have hampered the understanding contaminant migration through Hanford's vadose zone. Essential prerequisites for reducing vadose transport uncertainly include the development of accurate conceptual models and the development or adoption of monitoring techniques capable of delineating the current distributions of source contaminants and characterizing natural site heterogeneity. The Vadose Zone Transport Field Study (VZTFS) was conceived as part of the initiative to address the major uncertainties confronting vadose zone fate and transport predictions at the Hanford Site and to overcome the limitations of previous characterization attempts. Pacific Northwest National Laboratory (PNNL) is managing the VZTFS for DOE. The VZTFS will conduct field investigations that will improve the understanding of field-scale transport and lead to the development or identification of efficient and cost-effective characterization methods. Ideally, these methods will capture the extent of contaminant plumes using existing infrastructure (i.e., more than 1,300 steel-cased boreholes). The objectives of the VZTFS are to conduct controlled transport experiments at well-instrumented field sites at Hanford to

Characterization of Direct Push Vadose Zone Sediments from the 241-U Single-Shell Tank Farm

Energy Technology Data Exchange (ETDEWEB)

Brown, Christopher F.; Valenta, Michelle M.; Serne, R. Jeffrey; Bjornstad, Bruce N.; Lanigan, David C.; Iovin, Cristian; Clayton, Ray E.; Geiszler, Keith N.; Clayton, Eric T.; Kutnyakov, Igor V.; Baum, Steven R.; Lindberg, Michael J.; Orr, Robert D.

2007-12-20

The overall goals of the Tank Farm Vadose Zone Project, led by CH2M HILL Hanford Group, Inc., are 1) to define risks from past and future single-shell tank farm activities, 2) to identify and evaluate the efficacy of interim measures, and 3) to aid, via collection of geochemical information and data, the future decisions that must be made by the U.S. Department of Energy (DOE) regarding the near-term operations, future waste retrieval, and final closure activities for the single-shell tank Waste Management Areas (WMAs). For a more complete discussion of the goals of the Tank Farm Vadose Zone Project, see the overall work plan, Phase 1 RCRA Facility Investigation/Corrective Measures Study Work Plan for the Single-Shell Tank Waste Management Areas (DOE 1999). Specific details on the rationale for activities performed at WMA U are found in Crumpler (2003). To meet these goals, CH2M HILL Hanford Group, Inc., asked scientists from Pacific Northwest National Laboratory (PNNL) to perform detailed analyses of vadose zone sediment collected within the U Single-Shell Tank Farm. Specifically, this report contains all the geochemical and selected physical characterization data collected on vadose zone sediment recovered from ten direct push characterization holes emplaced to investigate vadose zone contamination associated with potential leaks within the 241-U Single-Shell Tank Farm. Specific tanks targeted during this characterization campaign included tanks 241-U-104/241-U-105, 241-U-110, and 241-U-112. Additionally, this report compiles data from direct push samples collected north of tank 241-U-201, as well as sediment collected from the background borehole (C3393). After evaluating all the characterization and analytical data, there is no question that the vadose zone in the vicinity of tanks 241-U-104 and 241-U-105 has been contaminated by tank-related waste. This observation is not new, as gamma logging of drywells in the area has identified uranium contamination at the

Deficiencies in Vadose Zone Understanding at the INEEL

Energy Technology Data Exchange (ETDEWEB)

Wood, Thomas Ronald; Bates, Dona Louise; Bishop, Carolyn Wagoner; Heard, Robert Eugene; Hubbell, Joel Michael; Hull, Laurence Charles; Lehman, Richard Michael; Magnuson, Swen O; Mattson, Earl Douglas; Mccarthy, James Michael; Porro, Indrek; Ritter, Paul David; Roddy, Michael Scott; Singler, Robert Edward; Smith, Richard Paul

2000-08-01

Subsurface contamination in the vadose zone, that portion of the subsurface pathway between land surface and an underlying aquifer, poses environmental problems at the Idaho National Engineering and Environmental Laboratory (INEEL) in eastern Idaho and across the U.S. Department of Energy complex. Assessing potential adverse impacts from these contaminated sites requires an understanding of the mechanisms controlling contaminant transport. Currently, vadose zone experts at the INEEL cannot with confidence predict the movement of water and contaminants in the complex, heterogeneous, fractured subsurface at the INEEL, especially within the vadose zone. In the draft version (Revision 1) of the Vadose Zone Deficiencies document, deficiencies in scientific understanding of flow and transport processes in the vadose zone at the INEEL were identified and grouped into 13 categories and recommendations were provided to address each of the deficiencies. The draft document provided the basis for an INEEL Vadose Zone Workshop that was conducted October 20 and 21, 1999, in Idaho Falls, Idaho. The workshop was conducted to group and rank the previously identified deficiencies and for the subsequent development of science plans to address the deficiencies that limit reliable predictions of water and contaminant movement in the subsurface. The workshop participants, comprising INEEL and scientists and project managers and non-INEEL scientists knowledgeable about the vadose zone, developed science- and technology-based recommendations derived through a series of technical sessions at the workshop. In this document, the final version of the Vadose Zone Deficiencies document, the draft document has been incorporated, largely intact, as well as the results from the workshop. The workshop participants grouped the deficiencies in vadose zone understanding at the INEEL into seven categories. These seven categories will be the focus areas of five science plans that are being developed to

Vadose Zone Journal: The first ten years

NARCIS (Netherlands)

Vrugt, J.A.; Or, D.; Young, M.H.

2013-01-01

Celebrating ten years of publication, the authors introduce a special section commemorating the anniversary of Vadose Zone Journal and reviewing the journal’s role in an evolving understanding of vadose zone science.

Optimization of remediation strategies using vadose zone monitoring systems

Science.gov (United States)

Dahan, Ofer

2016-04-01

In-situ bio-remediation of the vadose zone depends mainly on the ability to change the subsurface hydrological, physical and chemical conditions in order to enable development of specific, indigenous, pollutants degrading bacteria. As such the remediation efficiency is much dependent on the ability to implement optimal hydraulic and chemical conditions in deep sections of the vadose zone. These conditions are usually determined in laboratory experiments where parameters such as the chemical composition of the soil water solution, redox potential and water content of the sediment are fully controlled. Usually, implementation of desired optimal degradation conditions in deep vadose zone at full scale field setups is achieved through infiltration of water enriched with chemical additives on the land surface. It is assumed that deep percolation into the vadose zone would create chemical conditions that promote biodegradation of specific compounds. However, application of water with specific chemical conditions near land surface dose not necessarily results in promoting of desired chemical and hydraulic conditions in deep sections of the vadose zone. A vadose-zone monitoring system (VMS) that was recently developed allows continuous monitoring of the hydrological and chemical properties of deep sections of the unsaturated zone. The VMS includes flexible time-domain reflectometry (FTDR) probes which allow continuous monitoring of the temporal variation of the vadose zone water content, and vadose-zone sampling ports (VSPs) which are designed to allow frequent sampling of the sediment pore-water and gas at multiple depths. Implementation of the vadose zone monitoring system in sites that undergoes active remediation provides real time information on the actual chemical and hydrological conditions in the vadose zone as the remediation process progresses. Up-to-date the system has been successfully implemented in several studies on water flow and contaminant transport in

A comprehensive analysis of contaminant transport in the vadose zone beneath tank SX-109

International Nuclear Information System (INIS)

Ward, A.L.; Gee, G.W.; White, M.D.

1997-02-01

The Vadose Zone Characterization Project is currently investigating the subsurface distribution of gamma-emitting radionuclides in S and SX Waste Management Area (WMA-S-SX) located in the 200 West Area of the US Department of Energy's Hanford Site in southeastern Washington State. Spectral-gamma logging of boreholes has detected elevated 137 Cs concentrations as deep as 38 m, a depth considered excessive based on the assumed geochemistry of 137 Cs in Hanford sediments. Routine groundwater sampling under the Resource Conservation and Recovery Act (RCRA) have also detected elevated levels of site-specific contaminants downgradient of WMA-S-SX. The objective of this report is to explore the processes controlling the migration of 137 Cs, 99 Tc, and NO 3 through the vadose zone of WMA-S-SX, particularly beneath tank SX-109

Optimization of Remediation Conditions using Vadose Zone Monitoring Technology

Science.gov (United States)

Dahan, O.; Mandelbaum, R.; Ronen, Z.

2010-12-01

Success of in-situ bio-remediation of the vadose zone depends mainly on the ability to change and control hydrological, physical and chemical conditions of subsurface. These manipulations enables the development of specific, indigenous, pollutants degrading bacteria or set the environmental conditions for seeded bacteria. As such, the remediation efficiency is dependent on the ability to implement optimal hydraulic and chemical conditions in deep sections of the vadose zone. Enhanced bioremediation of the vadose zone is achieved under field conditions through infiltration of water enriched with chemical additives. Yet, water percolation and solute transport in unsaturated conditions is a complex process and application of water with specific chemical conditions near land surface dose not necessarily result in promoting of desired chemical and hydraulic conditions in deeper sections of the vadose zone. A newly developed vadose-zone monitoring system (VMS) allows continuous monitoring of the hydrological and chemical properties of the percolating water along deep sections of the vadose zone. Implementation of the VMS at sites that undergoes active remediation provides real time information on the chemical and hydrological conditions in the vadose zone as the remediation process progresses. Manipulating subsurface conditions for optimal biodegradation of hydrocarbons is demonstrated through enhanced bio-remediation of the vadose zone at a site that has been contaminated with gasoline products in Tel Aviv. The vadose zone at the site is composed of 6 m clay layer overlying a sandy formation extending to the water table at depth of 20 m bls. The upper 5 m of contaminated soil were removed for ex-situ treatment, and the remaining 15 m vadose zone is treated in-situ through enhanced bioremedaition. Underground drip irrigation system was installed below the surface on the bottom of the excavation. Oxygen and nutrients releasing powder (EHCO, Adventus) was spread below the

Characterization of Vadose Zone Sediment: Borehole 299-W23-19[SX -115] in the S-SX Waste Management Area

International Nuclear Information System (INIS)

Serne, R. Jeffrey; Schaef, Herbert T.; Bjornstad, Bruce N.; Lanigan, David C.; Gee, Glendon W.; Lindenmeier, Clark W.; Clayton, Ray E.; Legore, Virginia L.; Orr, Robert D.; O'Hara, Matthew J.; Brown, Christopher F.; Last, George V.; Kutnyakov, Igor V.; Burke, Deborah Sd; Wilson, Teresa C.; Williams, Bruce A.

2001-01-01

The Tank Farm Vadose Zone Project is led by CH2M HILL Hanford Group, Inc. Their goals include defining risks from past and future single-shell tank farm activities, identifying and evaluating the efficacy of interim measures, and collecting geo-technical information and data. The purpose of these activities is to support future decisions made by the U.S. Department of Energy regarding near-term operations, future waste retrieval, and final closure activities for the single-shell tank Waste Management Areas. To help in this effort, CH2M HILL contracted with scientists at Pacific Northwest National Laboratory to analyze sediment samples collected from borehole 299-W23-19. The conclusions reached from this study support specific mechanisms influencing subsurface migration of contaminants. The mechanisms are supported by the distributions of contaminants beneath tank farms. These observations will help DOE and CH2M HILL identify and implement viable remediation and closure activities

Characterization of Vadose Zone Sediment: Borehole 299-W23-19 [SX-115] in the S-SX Waste Management Area

Energy Technology Data Exchange (ETDEWEB)

Serne, R. Jeffrey; Bjornstad, Bruce N.; Lanigan, David C.; Gee, Glendon W.; Lindenmeier, Clark W.; Clayton, Ray E.; Legore, Virginia L.; O' Hara, Matthew J.; Brown, Christopher F.; Last, George V.; Kutnyakov, Igor V.; Burke, Deborah S.; Wilson, Teresa C.; Williams, Bruce A.

2008-09-11

This report was revised in September 2008 to remove acid-extractable sodium data from Tables 4.15 and 4.19. The sodium data was removed due to potential contamination introduced during the acid extraction process. The rest of the text remains unchanged from the original report issued in February 2002. The Tank Farm Vadose Zone Project is led by CH2M HILL Hanford Group, Inc. Their goals include defining risks from past and future single-shell tank farm activities, identifying and evaluating the efficacy of interim measures, and collecting geotechnical information and data. The purpose of these activities is to support future decisions made by the U.S. Department of Energy (DOE) regarding near-term operations, future waste retrieval, and final closure activities for the single-shell tank Waste Management Areas. To help in this effort, CH2M HILL Hanford Group, Inc. contracted with scientists at Pacific Northwest National Laboratory to analyze sediment samples collected from borehole 299-W23-19.

A/M Area Vadose Zone Monitoring Plan (U)

International Nuclear Information System (INIS)

Kupar, J.; Jarosch, T.R.; Jackson, D.G. Jr.; Looney, B.B.; Jerome, K.M.; Riha, B.D.; Rossabi, J.; Van Pelt, R.S.

1998-03-01

Characterization and monitoring data from implementation and the first two and one half years of vadose zone remediation operations indicate that this activity has substantially improved the performance of the A/M Area Groundwater Corrective Action Program. During this period, vadose zone remediation removed approximately 225, 000 lbs (100,000 Kg) of chlorinated solvents (CVOCs) from the subsurface. Further, vadose zone remediation system operation increased the overall CVOC removal rate of the A/M Area Groundwater Corrective Action by 300% to 500% during this period versus the groundwater pump and treat system along. Various support activities have been performed to support operation and documentation of performance of the vadose zone remediation system. These activities address performance of existing systems (contaminant distributions, zone of influence, and process monitoring data), evaluation of suspect sources, evaluation of alternative/enhancement technologies, and initial development of remediation goals. In particular, the most recent A/M vadose zone remediation support activities (described in WSRC-RP-97-109) were completed and the results provide key documentation about system performance

DEEP VADOSE ZONE TREATABILITY TEST PLAN

International Nuclear Information System (INIS)

Chronister, G.B.; Truex, M.J.

2009-01-01

(sm b ullet) Treatability test plan published in 2008 (sm b ullet) Outlines technology treatability activities for evaluating application of in situ technologies and surface barriers to deep vadose zone contamination (technetium and uranium) (sm b ullet) Key elements - Desiccation testing - Testing of gas-delivered reactants for in situ treatment of uranium - Evaluating surface barrier application to deep vadose zone - Evaluating in situ grouting and soil flushing

TWRS vadose zone contamination issue expert panel report

Energy Technology Data Exchange (ETDEWEB)

Shafer, D.S.

1997-05-01

When members were first canvassed for participation in the Vadose Zone Expert Panel the stated purpose for convening the Panel was to review a controversial draft report, the SX Tank Farm Report. This report was produced by a DOE Grand Junction Project Office (GJPO) contractor, RUST Geotech, now MACTEC-ERS, for the DOE Richland Office (DOERL). Three meetings were planned for June, July and August, 1995 to review the draft report and to complete a Panel report by mid-September. The Expert Panel has found its efforts confounded by various non-technical issues. The Expert Panel has chosen to address some of the non-technical issues in this Preface rather than to dilute the technical discussion that follows in the body of this independent expert panel status report (Panel Report). Rather than performing a straightforward manuscript review, the Panel was asked to resolve conflicting interpretations of gamma-ray logging measurements performed in vadose zone boreholes (drywells) surrounding the high-level radioactive wastes of the SX tank farm. There are numerous and complex technical issues that must be evaluated before the vertical and radial extent of contaminant migration at the SX tank farm can be accurately assessed. When the Panel first met in early June, 1996, it quickly became apparent that the scientific and technical issues were obscured by policy and institutional affairs which have polarized discussion among various segments of the Hanford organization. This situation reflects the kinds of institutional problems described separately in reports by the National Research Council of the National Academy of Sciences (NAS/NRC), The Hanford Tanks Environmental Impacts and Policy Choices and BmTiers to Science: Technical Management of the Department of Energy Environmental Remediation Program. The Vadose Zone Characterization Program, appears to be caught between conflicting pressures and organizational mandates, some imposed from outside DOE-RL and some self

VADOSE ZONE STUDIES AT AN INDUSTRIAL CONTAMINATED SITE: THE VADOSE ZONE MONITORING SYSTEM AND CROSS-HOLE GEOPHYSICS

OpenAIRE

Fernandez de Vera, Natalia; Beaujean, Jean; Jamin, Pierre; Nguyen, Frédéric; Dahan, Ofer; Vanclooster, Marnik; Brouyère, Serge

2014-01-01

In situ vadose zone characterization is essential to improve risk characterization and remediation measures for soil and groundwater contamination. However, most available technologies have been developed in the context of agricultural soils. Most of these methodologies are not applicable at industrial sites, where soils and contamination differ in origin and composition. In addition, they are applicable only in the first meters of soils, leaving deeper vadose zones with lack of informatio...

TWRS vadose zone contamination issue expert panel status report

International Nuclear Information System (INIS)

Shafer, D.S.

1997-01-01

When members were first canvassed for participation in the Vadose Zone Expert Panel the stated purpose for convening the Panel was to review a controversial draft report, the SX Tank Farm Report. This report was produced by a DOE Grand Junction Project Office (GJPO) contractor, RUST Geotech, now MACTEC-ERS, for the DOE Richland Office (DOERL). Three meetings were planned for June, July and August, 1995 to review the draft report and to complete a Panel report by mid-September. The Expert Panel has found its efforts confounded by various non-technical issues. The Expert Panel has chosen to address some of the non-technical issues in this Preface rather than to dilute the technical discussion that follows in the body of this independent expert panel status report (Panel Report). Rather than performing a straightforward manuscript review, the Panel was asked to resolve conflicting interpretations of gamma-ray logging measurements performed in vadose zone boreholes (drywells) surrounding the high-level radioactive wastes of the SX tank farm. There are numerous and complex technical issues that must be evaluated before the vertical and radial extent of contaminant migration at the SX tank farm can be accurately assessed. When the Panel first met in early June, 1996, it quickly became apparent that the scientific and technical issues were obscured by policy and institutional affairs which have polarized discussion among various segments of the Hanford organization. This situation reflects the kinds of institutional problems described separately in reports by the National Research Council of the National Academy of Sciences (NAS/NRC), The Hanford Tanks Environmental Impacts and Policy Choices and BmTiers to Science: Technical Management of the Department of Energy Environmental Remediation Program. The Vadose Zone Characterization Program, appears to be caught between conflicting pressures and organizational mandates, some imposed from outside DOE-RL and some self

Geochemical Processes Controlling Migration of High Level Wastes in Hanford's Vadose Zone

International Nuclear Information System (INIS)

Zachara, John M.; Serne, R. Jeffrey; Freshley, Mark D.; Mann, Frederick M.; Anderson, Frank J.; Wood, Marcus I.; Jones, Thomas E.; Myers, David A.

2007-01-01

High level nuclear wastes (HLW) from Hanford's plutonium reprocessing are stored in massive, buried, single-shell tanks in eighteen tank farms. The wastes were initially hot because of radioactive decay, and many exhibited extreme chemical character in terms of pH, salinity, and radionuclide concentration. At present, 67 of the 149 single shell tanks are suspected to have released over 1.9 million L of tank waste to the vadose zone, with most leak events occurring between 1950 and 1975. Boreholes have been placed through the largest vadose zone plumes to define the extent of contaminant migration, and to develop conceptual models of processes governing the transformation, retardation, and overall transport of tank waste residuals. Laboratory studies with sediments so collected have shown that ion exchange, precipitation and dissolution, and surface complexation reactions have occurred between the HLW and subsurface sediments moderating their chemical character, and retarding the migration of select contaminants. Processes suspected to facilitate the far-field migration of immobile radionuclides including stable aqueous complex formation and mobile colloids were found to be potentially operative, but unlikely to occur in the field, with the exception of cyanide-facilitated migration of 60Co. Fission product oxyanions are the most mobile of tank waste constituents because their adsorption is suppressed by large concentrations of waste anions; the vadose zone clay fraction is negative in surface charge; and, unlike Cr, their reduced forms are unstable in oxidizing environments. Reaction/process-based transport modeling is beginning to be used for predictions of future contaminant mobility and plume evolution

Vadose zone characterisation at industrial contaminated sites

OpenAIRE

Fernandez de Vera, Natalia; Dahan, Ofer; Dassargues, Alain; Vanclooster, Marnik; Nguyen, Frédéric; Brouyère, Serge

2015-01-01

In order to improve risk characterization and remediation measures for soil and groundwater contamination, there is a need to improve in situ vadose zone characterization. However, most available technologies have been developed in the context of agricultural soils. Such methodologies are not applicable at industrial sites, where soils and contamination differ in origin and composition. To overcome such difficulties, a vadose zone experiment has been setup at a former industrial site in ...

1999 vadose zone monitoring plan and guidance for subsequent years

International Nuclear Information System (INIS)

Horton, D.G.; Reidel, S.P.; Last, G.V.

1998-08-01

The US Department of Energy's Hanford Site has the most diverse and largest amounts of radioactive waste in the US. The majority of the liquid waste was disposed to the soil column where much of it remains today. This document provides the rationale and general framework for vadose zone monitoring at cribs, ditches, trenches and other disposal facilities to detect new sources of contamination and track the movement of existing contamination in the vadose zone for the protection of groundwater. The document provides guidance for subsequent site-specific vadose zone monitoring plans and includes a brief description of past vadose monitoring activities (Chapter 3); the results of the Data Quality Objective process used for this plan (Chapter 4); a prioritization of liquid waste disposal sites for vadose monitoring (Chapter 5 and Appendix B); a general Monitoring and Analysis Plan (Chapter 6); a general Quality Assurance Project Plan (Appendix A), and a description of vadose monitoring activities planned for FY 1999 (Appendix C)

Vadose Zone Transport Field Study: Summary Report

Energy Technology Data Exchange (ETDEWEB)

Ward, Andy L.; Conrad, Mark E.; Daily, William D.; Fink, James B.; Freedman, Vicky L.; Gee, Glendon W.; Hoversten, Gary M.; Keller, Jason M.; Majer, Ernest L.; Murray, Christopher J.; White, Mark D.; Yabusaki, Steven B.; Zhang, Z. F.

2006-07-31

From FY 2000 through FY 2003, a series of vadose zone transport field experiments were conducted as part of the U.S. Department of Energy’s Groundwater/Vadose Zone Integration Project Science and Technology Project, now known as the Remediation and Closure Science Project, and managed by the Pacific Northwest National Laboratory (PNNL). The series of experiments included two major field campaigns, one at a 299-E24-11 injection test site near PUREX and a second at a clastic dike site off Army Loop Road. The goals of these experiments were to improve our understanding of vadose zone transport processes; to develop data sets to validate and calibrate vadose zone flow and transport models; and to identify advanced monitoring techniques useful for evaluating flow-and-transport mechanisms and delineating contaminant plumes in the vadose zone at the Hanford Site. This report summarizes the key findings from the field studies and demonstrates how data collected from these studies are being used to improve conceptual models and develop numerical models of flow and transport in Hanford’s vadose zone. Results of these tests have led to a better understanding of the vadose zone. Fine-scale geologic heterogeneities, including grain fabric and lamination, were observed to have a strong effect on the large-scale behavior of contaminant plumes, primarily through increased lateral spreading resulting from anisotropy. Conceptual models have been updated to include lateral spreading and numerical models of unsaturated flow and transport have revised accordingly. A new robust model based on the concept of a connectivity tensor was developed to describe saturation-dependent anisotropy in strongly heterogeneous soils and has been incorporated into PNNL’s Subsurface Transport Over Multiple Phases (STOMP) simulator. Application to field-scale transport problems have led to a better understanding plume behavior at a number of sites where lateral spreading may have dominated waste

Installation and sampling of vadose zone monitoring devices

International Nuclear Information System (INIS)

Bergeron, S.M.; Strickland, D.J.; Pearson, R.

1987-10-01

A vadose zone monitoring system was installed in a sanitary landfill near the Y-12 facility on the Department of Energy's Oak Ridge, Tennessee Reservation. The work was completed as part of the LLWDDD program to develop, design, and demonstrate new low level radioactive waste disposal monitoring methods. The objective of the project was to evaluate the performance of three types of vadose zone samplers within a similar hydrogeologic environment for use as early detection monitoring devices. The three different types of samplers included the Soil Moisture Equipment Corporation Pressure-Vacuum samplers (Models 1920 and 1940), and the BAT Piezometer (Model MK II) manufactured by BAT Envitech, Inc. All three samplers are designed to remove soil moisture from the vadose (unsaturated) zone. Five clusters of three holes each were drilled to maximum depths of 45 ft around part of the periphery of the landfill. Three samplers, one of each type, were installed at each cluster location. Water samples were obtained from 13 of the 15 samplers and submitted to Martin Marietta for analysis. All three samplers performed satisfactorily when considering ease of installation, required in-hole development, and ability to collect water samples from the vadose zone. Advantages and disadvantages of each sampler type are discussed in the main report

Effect of vadose zone on the steady-state leakage rates from landfill barrier systems

International Nuclear Information System (INIS)

Celik, B.; Rowe, R.K.; Unlue, K.

2009-01-01

Leakage rates are evaluated for a landfill barrier system having a compacted clay liner (CCL) underlain by a vadose zone of variable thickness. A numerical unsaturated flow model SEEP/W is used to simulate the moisture flow regime and steady-state leakage rates for the cases of unsaturated zones with different soil types and thicknesses. The results of the simulations demonstrate that harmonic mean hydraulic conductivity of coarse textured vadose zones is 3-4 orders of magnitude less than saturated hydraulic conductivity; whereas, the difference is only one order of magnitude for fine textured vadose zones. For both coarse and fine textured vadose zones, the effective hydraulic conductivity of the barrier system and the leakage rate to an underlying aquifer increases with increasing thickness of the vadose zone and ultimately reaches an asymptotic value for a coarse textured vadose zone thickness of about 10 m and a fine textured vadose zone thickness of about 5 m. Therefore, the fine and coarse textured vadose zones thicker than about 5 m and 10 m, respectively, act as an effective part of the barrier systems examined. Although the thickness of vadose zone affects the effective hydraulic conductivity of the overall barrier system, the results demonstrated that the hydraulic conductivity of the CCL is the dominant factor controlling the steady-state leakage rates through barrier systems having single low permeability clay layers

Global Patterns of Legacy Nitrate Storage in the Vadose Zone

Science.gov (United States)

Ascott, M.; Gooddy, D.; Wang, L.; Stuart, M.; Lewis, M.; Ward, R.; Binley, A. M.

2017-12-01

Global-scale nitrogen (N) budgets have been developed to quantify the impact of man's influence on the nitrogen cycle. However, these budgets often do not consider legacy effects such as accumulation of nitrate in the deep vadose zone. In this presentation we show that the vadose zone is an important store of nitrate which should be considered in future nitrogen budgets for effective policymaking. Using estimates of depth to groundwater and nitrate leaching for 1900-2000, we quantify for the first time the peak global storage of nitrate in the vadose zone, estimated as 605 - 1814 Teragrams (Tg). Estimates of nitrate storage are validated using previous national and basin scale estimates of N storage and observed groundwater nitrate data for North America and Europe. Nitrate accumulation per unit area is greatest in North America, China and Central and Eastern Europe where thick vadose zones are present and there is an extensive history of agriculture. In these areas the long solute travel time in the vadose zone means that the anticipated impact of changes in agricultural practices on groundwater quality may be substantially delayed. We argue that in these areas use of conventional nitrogen budget approaches is inappropriate and their continued use will lead to significant errors.

Summary of Vadose -- Zone Conceptual Models for Flow and Contaminant Transport and 1999 - 2003 Progress on Resolving Deficiencies in Understanding the Vadose Zone at the INEEL

Energy Technology Data Exchange (ETDEWEB)

Robert C. Starr; Dana L. Dettmers; Brennon R. Orr; Thomas R. Wood

2003-12-01

The thick vadose zone that underlies the Idaho National Engineering and Environmental Laboratory has been recognized both as an avenue through which contaminants disposed at or near the ground surface can migrate to groundwater in the underlying Eastern Snake River Plain aquifer, and as a barrier to the movement of contaminants into the aquifer. Flow and contaminant transport in the vadose zone at the INEEL is complicated by the highly heterogeneous nature of the geologic framework and by the variations in the behavior of different contaminants in the subsurface. The state of knowledge concerning flow and contaminant transport in the vadose zone at and near the INEEL IN 1999 was summarized in Deficiencies in Vadose Zone Understanding at the Idaho National Engineering and Environmental Laboratory (Wood et al., 2000). These authors identified deficiencies in knowledge of flow and contaminant transport processes in the vadose zone, and provided recommendations for additional work that should be conducted to address these deficiencies. In the period since (Wood et al., 2000) was prepared, research has been published that, to some degree, address these deficiencies. This document provides a bibliography of reports, journal articles, and conference proceedings published 1999 through mid-2003 that are relevant to the vadose zone at or near the INEEL and provides a brief description of each work. Publications that address specific deficiencies or recommendations are identified, and pertinent information from selected publications is presented.

Model Package Report: Central Plateau Vadose Zone Geoframework Version 1.0

Energy Technology Data Exchange (ETDEWEB)

Springer, Sarah D.

2018-03-27

The purpose of the Central Plateau Vadose Zone (CPVZ) Geoframework model (GFM) is to provide a reasonable, consistent, and defensible three-dimensional (3D) representation of the vadose zone beneath the Central Plateau at the Hanford Site to support the Composite Analysis (CA) vadose zone contaminant fate and transport models. The GFM is a 3D representation of the subsurface geologic structure. From this 3D geologic model, exported results in the form of point, surface, and/or volumes are used as inputs to populate and assemble the various numerical model architectures, providing a 3D-layered grid that is consistent with the GFM. The objective of this report is to define the process used to produce a hydrostratigraphic model for the vadose zone beneath the Hanford Site Central Plateau and the corresponding CA domain.

Installation of a Hydrologic Characterization Network for Vadose Zone Monitoring of a Single-Shell Tank Farm at the U. S. Department of Energy Hanford Site

International Nuclear Information System (INIS)

Gee, Glendon W.; Ward, Anderson L.; Ritter, Jason C.; Sisson, James B.; Hubbell, Joel M.; Sydnor, Harold A.

2001-01-01

The Pacific Northwest National Laboratory, in collaboration with the Idaho National Engineering and Environmental Laboratory and Duratek Federal Services, deployed a suite of vadose-zone instruments at the B Tank Farm in the 200 E Area of the Hanford Site, near Richland, Washington, during the last quarter of FY 2001. The purpose of the deployment was to obtain in situ hydrologic characterization data within the vadose zone of a high-level-waste tank farm. Eight sensor nests, ranging in depth from 67 m (220 ft) below ground surface (bgs) to 0.9 m (3 ft) bgs were placed in contact with vadose-zone sediments inside a recently drilled, uncased, borehole (C3360) located adjacent to Tank B-110. The sensor sets are part of the Vadose Zone Monitoring System and include advanced tensiometers, heat dissipation units, frequency domain reflectometers, thermal probes, and vadose zone solution samplers. Within the top meter of the surface, a water flux meter was deployed to estimate net infiltration from meteoric water (rain and snowmelt) sources. In addition, a rain gage was located within the tank farm to document on-site precipitation events. All sensor units, with the exception of the solution samplers, were connected to a solar-powered data logger located within the tank farm. Data collected from these sensors are currently being accessed by modem and cell phone and will be analyzed as part of the DOE RL31SS31 project during the coming year (FY 2001)

Characterization of Direct Push Vadose Zone Sediments from the T and TY Waste Management Areas

Energy Technology Data Exchange (ETDEWEB)

Brown, Christopher F.; Valenta, Michelle M.; Serne, R. Jeffrey; Bjornstad, Bruce N.; Lanigan, David C.; Iovin, Cristian; Clayton, Ray E.; Geiszler, Keith N.; Clayton, Eric T.; Kutnyakov, Igor V.; Baum, Steven R.; Lindberg, Michael J.; Orr, Robert D.

2007-06-08

This report contains all the geochemical and selected physical characterization data collected on vadose zone sediment recovered from 5 direct push characterization holes emplaced to investigate vadose zone contamination associated with leaks from tanks 241-TY-105 (UPR-200-W-152) and 241-TY-106 (UPR-200-W-153). Tank 241-TY-105 is estimated to have leaked 35,000 gal of tributyl phosphate (TBP) waste from the uranium recovery process to the vadose zone in 1960. Tank 241-TY-106 is estimated to have leaked 20,000 gal of TBP-uranium recovery waste to the vadose zone in 1959. Although several drywells in the vicinity of tank 241-TY-106 contain measurable quantities of cesium-137 and/or cobalt-60, their relatively low concentrations indicate that the contaminant inventory in the vadose zone around tank 241-TY-106 is quite small. Additionally, this report contains all the geochemical and selected physical characterization data collected on vadose zone sediment recovered from 7 direct push characterization holes emplaced to investigate vadose zone contamination associated with an overfill event and leak from tank 241-T-101.

Foam-Delivery of Remedial Amendments for Enhanced Vadose Zone Metals and Radionuclides Remediation

International Nuclear Information System (INIS)

Zhong, L.; Szecsody, J.E.; Dresel, P.E.; Zhang, Z.F.; Qafoku, N.P.

2009-01-01

The remediation of metals and radionuclides contamination, such as Cr(VI), Tc-99, and Sr-90 in the U.S. DOE Hanford Site vadose zone is a critical need. Water-based remedial amendments delivery to the deep vadose zone is facing significant technical challenges. Water-based delivery will easily leach out the highly mobile pollutants therefore contaminate the underlying aquifer. Preferential flow of the amendment-laden solution in the vadose zone due to the formation heterogeneity is difficult to overcome, resulting in bypassing of the less permeable zones. Foam has unique transport properties in the vadose zone that enable mitigation on the mobilization of mobile contaminants and enhance the sweeping over heterogeneous systems. Calcium polysulfide (CPS) is a remedial amendment that can be used to reduce and immobilize hexavalent chromium [Cr(VI)] and other redox-sensitive radionuclides/metals in the vadose zone. The delivery of CPS to the vadose zone using foam and the immobilization of Cr(VI) via reduction by the foam-delivered CPS was investigated in this study. Batch tests were conducted to select the foam-generating CPS-surfactant solutions, to determine the solution foamability and the reducing potential of CPS-containing foams, and to study the influence of foam quality, surfactant concentration, and CPS concentration on foam stability. Column experiments were performed to test the foam delivery of CPS to sediments under conditions similar to field vadose zone, to study the foam transport and interaction with sediments, and to determine the extent of Cr(VI) immobilization using this novel delivery approach. CPS-containing foams with high reducing potential were prepared based on the batch tests. Sediment reduction by foam-delivered CPS was observed in the column studies. Significant mobilization of Cr(VI) from sediments occurred when CPS was delivered in aqueous solution. The Cr(VI) mobilization was minimized when CPS was delivered by foams, resulting in

Colloid Facilitated Transport of Radioactive Cations in the Vadose Zone: Field Experiments Oak Ridge

Energy Technology Data Exchange (ETDEWEB)

James E. Saiers

2012-09-20

The overarching goal of this study was to improve understanding of colloid-facilitated transport of radioactive cations through unsaturated soils and sediments. We conducted a suite of laboratory experiments and field experiments on the vadose-zone transport of colloids, organic matter, and associated contaminants of interest to the U.S. Department of Energy (DOE). The laboratory and field experiments, together with transport modeling, were designed to accomplish the following detailed objectives: 1. Evaluation of the relative importance of inorganic colloids and organic matter to the facilitation of radioactive cation transport in the vadose zone; 2. Assessment of the role of adsorption and desorption kinetics in the facilitated transport of radioactive cations in the vadose zone; 3. Examination of the effects of rainfall and infiltration dynamics and in the facilitated transport of radioactive cations through the vadose zone; 4. Exploration of the role of soil heterogeneity and preferential flow paths (e.g., macropores) on the facilitated transport of radioactive cations in the vadose zone; 5. Development of a mathematical model of facilitated transport of contaminants in the vadose zone that accurately incorporates pore-scale and column-scale processes with the practicality of predicting transport with readily available parameters.

Borehole environmental tracers for evaluating net infiltration and recharge through desert bedrock

Science.gov (United States)

Heilweil, V.M.; Solomon, D.K.; Gardner, P.M.

2006-01-01

Permeable bedrock aquifers in arid regions are being increasingly developed as water supplies, yet little is generally known about recharge processes and spatial and temporal variability. Environmental tracers from boreholes were used in this study to investigate net infiltration and recharge to the fractured Navajo Sandstone aquifer. Vadose zone tracer profiles at the Sand Hollow study site in southwestern Utah look similar to those of desert soils at other sites, indicating the predominance of matrix flow. However, recharge rates are generally higher in the Navajo Sandstone than in unconsolidated soils in similar climates because the sandstone matrix allows water movement but not root penetration. Water enters the vadose zone either as direct infiltration of precipitation through exposed sandstone and sandy soils or as focused infiltration of runoff. Net infiltration and recharge exhibit extreme spatial variability. High-recharge borehole sites generally have large amounts of vadose zone tritium, low chloride concentrations, and small vadose zone oxygen-18 evaporative shifts. Annual net-infiltration and recharge rates at different locations range from about 1 to 60 mm as determined using vadose zone tritium, 0 to 15 mm using vadose zone chloride, and 3 to 60 mm using groundwater chloride. Environmental tracers indicate a cyclical net-infiltration and recharge pattern, with higher rates earlier in the Holocene and lower rates during the late Holocene, and a return to higher rates during recent decades associated with anomalously high precipitation during the latter part of the 20th century. The slightly enriched stable isotopic composition of modern groundwater indicates this recent increase in precipitation may be caused by a stronger summer monsoon or winter southern Pacific El Nin??o storm track. ?? Soil Science Society of America.

Rectangular Schlumberger resistivity arrays for delineating vadose zone clay-lined fractures in shallow tuff

International Nuclear Information System (INIS)

Miele, M.; Laymon, D.; Gilkeson, R.; Michelotti, R.

1996-01-01

Rectangular Schlumberger arrays can be used for 2-dimensional lateral profiling of apparent resistivity at a unique current electrode separation, hence single depth of penetration. Numerous apparent resistivity measurements are collected moving the potential electrodes (fixed MN spacing) within a rectangle of defined dimensions. The method provides a fast, cost-effective means for the collection of dense resistivity data to provide high-resolution information on subsurface hydrogeologic conditions. Several rectangular Schlumberger resistivity arrays were employed at Los Alamos National Laboratory (LANL) from 1989 through 1995 in an area adjacent to and downhill from an outfall pipe, septic tank, septic drainfield, and sump. Six rectangular arrays with 2 AB spacings were used to delineate lateral low resistivity anomalies that may be related to fractures that contain clay and/or vadose zone water. Duplicate arrays collected over a three year time period exhibited very good data repeatability. The properties of tritium make it an excellent groundwater tracer. Because tritium was present in discharged water from all of the anthropogenic sources in the vicinity it was used for this purpose. One major low resistivity anomaly correlates with relatively high tritium concentrations in the tuff. This was determined from borehole samples collected within and outside of the anomalous zone. The anomaly is interpreted to be due to fractures that contain clay from the soil profile. The clay was deposited in the fractures by aeolian processes and by surface water infiltration. The fractures likely served as a shallow vadose zone groundwater pathway

Deep Vadose Zone Treatability Test of Soil Desiccation for the Hanford Central Plateau: Final Report

Energy Technology Data Exchange (ETDEWEB)

Truex, Michael J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Chronister, Glen B. [CH2M Hill Plateau Remediation Co., Richland, WA (United States); Strickland, Christopher E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Johnson, Christian D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Tartakovsky, Guzel D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Oostrom, Martinus [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Clayton, Ray E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Johnson, Timothy C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Freedman, Vicky L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Rockhold, Mark L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Greenwood, William J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Peterson, John E. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Hubbard, Susan S. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Ward, Anderson L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2018-02-20

Some of the inorganic and radionuclide contaminants in the deep vadose zone at the Hanford Site are at depths where direct exposure pathways are not of concern, but may need to be remediated to protect groundwater. The Department of Energy developed a treatability test program for technologies to address Tc-99 and uranium in the deep vadose zone. These contaminants are mobile in the subsurface environment, have been detected at high concentrations deep in the vadose zone, and at some locations have reached groundwater. The treatability test of desiccation described herein was conducted as an element of the deep vadose zone treatability test program. Desiccation was shown to be a potentially effective vadose zone remediation technology to protect groundwater when used in conjunction with a surface infiltration barrier.

TECHNICAL BASIS FOR EVALUATING SURFACE BARRIERS TO PROTECT GROUNDWATER FROM DEEP VADOSE ZONE CONTAMINATION

International Nuclear Information System (INIS)

Fayer, J.M.; Freedman, V.L.; Ward, A.L.; Chronister, G.B.

2010-01-01

The U.S. DOE and its predecessors released nearly 2 trillion liters (450 billion gallons) of contaminated liquid into the vadose zone at the Hanford Site. Some of the contaminants currently reside in the deeper parts of the vadose zone where they are much less accessible to characterization, monitoring, and typical remediation activities. The DOE Richland Operations Office (DOE-RL) prepared a treatability test plan in 2008 to examine remediation options for addressing contaminants in the deep vadose zone; one of the technologies identified was surface barriers (also known as engineered barriers, covers, and caps). In the typical configuration, the contaminants are located relatively close to the surface, generally within 15 m, and thus they are close to the base of the surface barrier. The proximity of the surface barrier under these conditions yielded few concerns about the effectiveness of the barrier at depth, particularly for cases in which the contaminants were in a lined facility. At Hanford, however, some unlined sites have contaminants located well below depths of 15 m. The issue raised about these sites is the degree of effectiveness of a surface barrier in isolating contaminants in the deep vadose zone. Previous studies by Hanford Site and PNNL researchers suggest that surface barriers have the potential to provide a significant degree of isolation of deep vadose zone contaminants. The studies show that the actual degree of isolation is site-specific and depends on many factors, including recharge rates, barrier size, depth of contaminants, geohydrologic properties ofthe sediments, and the geochemical interactions between the contaminants and the sediments. After the DOE-RL treatability test plan was published, Pacific Northwest National Laboratory was contracted to review the information available to support surface barrier evaluation for the deep vadose zone, identify gaps in the information and outcomes necessary to fill the data gaps, and outline

Bioremediation of RDX in the vadose zone beneath the Pantex Plant

Energy Technology Data Exchange (ETDEWEB)

Shull, T.L.; Speitel, G.E. Jr.; McKinney, D.C. [Univ. of Texas, Austin, TX (United States). Dept. of Civil Engineering

1999-01-01

The presence of dissolved high explosives (HE), in particular RDX and HMX, is well documented in the perched aquifer beneath the Pantex Plant, but the distribution of HE in the vadose zone has not yet been well defined. Although current remediation activities focus on the contamination in the perched aquifer, eventually regulatory concern is likely to turn to the residual contamination in the vadose zone. Sources of HE include the infiltration of past wastewater discharges from several HE-processing facilities through the ditch drainage system and leachate from former Landfill 3. With limited existing data on the HE distribution in the vadose zone and without preventive action, it must be assumed that residual HE could be leached into infiltrating water, providing a continuing supply of contamination to the perched aquifer. The purpose of this project was to more closely examine the fate and transport of HE in the vadose zone through mathematical modeling and laboratory experimentation. In particular, this report focuses on biodegradation as one possible fate of HE. Biodegradation of RDX in the vadose zone was studied because it is both present in highest concentration and is likely to be of the greatest regulatory concern. This study had several objectives: determine if indigenous soil organisms are capable of RDX biodegradation; determine the impact of electron acceptor availability and nutrient addition on RDX biodegradation; determine the extent of RDX mineralization (i.e., conversion to inorganic carbon) during biodegradation; and estimate the kinetics of RDX biodegradation to provide information for mathematical modeling of fate and transport.

Notice of Construction for Tank Waste Remediation System Vadose Zone Characterization

International Nuclear Information System (INIS)

HILL, J.S.

2000-01-01

The following description and any attachments and references are provided to the Washington State Department of Health (WDOH), Division of Radiation Protection, Air Emissions and Defense Waste Section as a notice of construction (NOC) in accordance with Washington Administrative Code (WAC) 246-247, Radiation Protection--Air Emissions. The WAC 246-247-060, ''Applications, registration, and licensing'', states ''This section describes the information requirements for approval to construct, modify, and operate an emission unit. Any NOC requires the submittal of information listed in Appendix A,'' Appendix A (WAC 246-247-1 10) lists the requirements that must be addressed. The original NOC was submitted in May of 1999 as DOE/TU-99-34. Additionally, the following description, attachments and references are provided to the U.S. Environmental Protection Agency (EPA) as an NOC, in accordance with Title 40 Code of Federal Regulations (CFR), Part 61, ''National Emission Standards for Hazardous Air Pollutants.'' The information required for submittal to the EPA is specified in 40 CFR 61.07. The potential emissions from this activity are estimated to provide less than 0.1 millirem/year total effective dose equivalent (TEDE) to the hypothetical offsite maximally exposed individual (MEI), and commencement is needed within a short time frame. Therefore, this application is also intended to provide notification of the anticipated date of initial startup in accordance with the requirement listed in 40 CFR 61.09(axl), and it is requested that approval of this application will also constitute EPA acceptance of this initial start-up notification. Written notification of the actual date of initial startup, in accordance with the requirement listed in 40 CFR 61.09(a)(2) will be provided at a later date. This NOC covers the activities associated with vadose zone characterization within the Single-Shell Tank Farms located in the 200-East and 200-West Areas of the Hanford Site. Vadose zone

HEAT AND MASS TRANSFER IN THE VADOSE ZONE WITH PLANT ROOTS. (R825414)

Science.gov (United States)

AbstractThe vadose zone is the intermediate medium between the atmosphere and groundwater. The modeling of the processes taking place in the vadose zone needs different approaches to those needed for groundwater transport problems because of the marked changes in envi...

Short-term and long-term Vadose zone monitoring: Current technologies, development, and applications

International Nuclear Information System (INIS)

Faybishenko, Boris

1999-01-01

At Hanford, Savannah River, Oak Ridge, Idaho National Engineering and Environmental Laboratory (INEEL), and other DOE sites, field vadose zone observations have shown complex water seepage and mass transport behavior in a highly heterogeneous, thick vadose zone on a variety of scales. Recent investigation showed that severe contamination of soils and groundwater by organic contaminant and nuclear waste occurred because of water seepage and contaminant transport along localized, preferential, fast flow within the heterogeneous vadose zone. However, most of the existing characterization and monitoring methods are not able to locate these localized and persistent preferential pathways associated with specific heterogeneous geologic features, such as clastic dikes, caliche layers, or fractures. In addition, changes in the chemical composition of moving and indigenous solutes, particularly sodium concentration, redox conditions, biological transformation of organic materials, and high temperature, may significantly alter water, chemicals, and bio-transformation exchange between the zones of fast flow and the rest of the media. In this paper, using the data from Hanford and INEEL sites, we will (1) present evidence that central problems of the vadose zone investigations are associated with preferential, fast flow phenomena and accelerated migration of organic and radioactive elements, (2) identify gaps in current characterization and monitoring technologies, and (3) recommend actions for the development of advanced vadose zone characterization and monitoring methods using a combination of hydrologic, geochemical, and geophysical techniques

Evaluation of Soil Flushing for Application to the Deep Vadose Zone in the Hanford Central Plateau

Energy Technology Data Exchange (ETDEWEB)

Truex, Michael J.; Oostrom, Martinus; Zhang, Z. F.; Carroll, Kenneth C.; Schramke, Janet A.; Wietsma, Thomas W.; Tartakovsky, Guzel D.; Gordon, Kathryn A.; Last, George V.

2010-11-01

Soil flushing was included in the Deep Vadose Zone Treatability Test Plan for the Hanford Central Plateau as a technology with the potential to remove contaminants from the vadose zone. Soil flushing operates through the addition of water, and if necessary an appropriate mobilizing agent, to mobilize contaminants and flush them from the vadose zone and into the groundwater where they are subsequently captured by a pump-and-treat system. There are uncertainties associated with applying soil flushing technology to contaminants in the deep vadose zone at the Hanford Central Plateau. The modeling and laboratory efforts reported herein are intended to provide a quantitative assessment of factors that impact water infiltration and contaminant flushing through the vadose zone and into the underlying groundwater. Once in the groundwater, capture of the contaminants would be necessary, but this aspect of implementing soil flushing was not evaluated in this effort. Soil flushing was evaluated primarily with respect to applications for technetium and uranium contaminants in the deep vadose zone of the Hanford Central Plateau.

Climate variability and vadose zone controls on damping of transient recharge

Science.gov (United States)

Corona, Claudia R.; Gurdak, Jason J.; Dickinson, Jesse; Ferré, T.P.A.; Maurer, Edwin P.

2017-01-01

Increasing demand on groundwater resources motivates understanding of the controls on recharge dynamics so model predictions under current and future climate may improve. Here we address questions about the nonlinear behavior of flux variability in the vadose zone that may explain previously reported teleconnections between global-scale climate variability and fluctuations in groundwater levels. We use hundreds of HYDRUS-1D simulations in a sensitivity analysis approach to evaluate the damping depth of transient recharge over a range of periodic boundary conditions and vadose zone geometries and hydraulic parameters that are representative of aquifer systems of the conterminous United States (U.S). Although the models were parameterized based on U.S. aquifers, findings from this study are applicable elsewhere that have mean recharge rates between 3.65 and 730 mm yr–1. We find that mean infiltration flux, period of time varying infiltration, and hydraulic conductivity are statistically significant predictors of damping depth. The resulting framework explains why some periodic infiltration fluxes associated with climate variability dampen with depth in the vadose zone, resulting in steady-state recharge, while other periodic surface fluxes do not dampen with depth, resulting in transient recharge. We find that transient recharge in response to the climate variability patterns could be detected at the depths of water levels in most U.S. aquifers. Our findings indicate that the damping behavior of transient infiltration fluxes is linear across soil layers for a range of texture combinations. The implications are that relatively simple, homogeneous models of the vadose zone may provide reasonable estimates of the damping depth of climate-varying transient recharge in some complex, layered vadose zone profiles.

Tackling the Challenge of Deep Vadose Zone Remediation at the Hanford Site

Science.gov (United States)

Morse, J. G.; Wellman, D. M.; Gephart, R.

2010-12-01

The Central Plateau of the Hanford Site in Washington State contains some 800 waste disposal sites where 1.7 trillion liters of contaminated water was once discharged into the subsurface. Most of these sites received liquids from the chemical reprocessing of spent uranium fuel to recover plutonium. In addition, 67 single shell tanks have leaked or are suspected to have leaked 3.8 million liters of high alkali and aluminate rich cesium-contaminated liquids into the sediment. Today, this inventory of subsurface contamination contains an estimated 550,000 curies of radioactivity and 150 million kg (165,000 tons) of metals and hazardous chemicals. Radionuclides range from mobile 99Tc to more immobilized 137Cs, 241Am, uranium, and plutonium. A significant fraction of these contaminants likely remain within the deep vadose zone. Plumes of groundwater containing tritium, nitrate, 129I and other contaminants have migrated through the vadose zone and now extend outward from the Central Plateau to the Columbia River. During most of Hanford Site history, subsurface studies focused on groundwater monitoring and characterization to support waste management decisions. Deep vadose zone studies were not a priority because waste practices relied upon that zone to buffer contaminant releases into the underlying aquifer. Remediation of the deep vadose zone is now central to Hanford Site cleanup because these sediments can provide an ongoing source of contamination to the aquifer and therefore to the Columbia River. However, characterization and remediation of the deep vadose zone pose some unique challenges. These include sediment thickness; contaminant depth; coupled geohydrologic, geochemical, and microbial processes controlling contaminant spread; limited availability and effectiveness of traditional characterization tools and cleanup remedies; and predicting contaminant behavior and remediation performance over long time periods and across molecular to field scales. The U

Transport and degradation of fuel compounds in the vadose zone

DEFF Research Database (Denmark)

Christophersen, Mette; Broholm, Mette Martina; Kjeldsen, Peter

2002-01-01

Fuel has been spilled in the vadose zone at many sites. An artificial jet fuel source has been installed in a vadose zone at Airbase Værløse. The field experiment is conducted to investigate the natural attenuation potential in order to obtain better evaluations of the risk for groundwater...... contamination. Field data and calculations of mass in the pore air indicate a large loss within a short period of time. Laboratory experiments and isotopic analysis proves that biodegradation is occurring. The results indicate that for most compounds degradation is significant reducing the concentrations...

Characterization and Potential Remediation Approaches for Vadose Zone Contamination at Hanford 241-SX Tank Farm-13235

International Nuclear Information System (INIS)

Eberlein, Susan J.; Sydnor, Harold A.; Parker, Danny L.; Glaser, Danney R.

2013-01-01

Unplanned releases of radioactive and hazardous wastes have occurred at the 241-SX Tank Farm on the U.S. Department of Energy Hanford Site in southeast Washington State. Interim and long-term mitigation efforts are currently under evaluation for 241-SX Tank Farm. Two contiguous interim surface barriers have been designed for deployment at 241-SX Tank Farm to reduce future moisture infiltration; however, construction of the surface barriers has been deferred to allow testing of alternative technologies for soil moisture reduction and possibly contaminant source term reduction. Previous tests performed by other organizations at the Hanford Site have demonstrated that: vadose zone desiccation using large diameter (greater than 4 inch) boreholes is feasible; under certain circumstances, mobile contaminants may be removed in addition to water vapor; and small diameter (approximately 2 inch) boreholes (such as those placed by the direct push hydraulic hammer) can be used to perform vapor extractions. Evaluation of the previous work combined with laboratory test results have led to the design of a field proof-of-principle test to remove water and possibly mobile contaminants at greater depths, using small boreholes placed with the direct push unit

Characterization and Potential Remediation Approaches for Vadose Zone Contamination at Hanford 241-SX Tank Farm - 13235

Energy Technology Data Exchange (ETDEWEB)

Eberlein, Susan J.; Sydnor, Harold A.; Parker, Danny L.; Glaser, Danney R. [Washington River Protection Solutions, P.O. Box 850, Richland, WA, 99352 (United States)

2013-07-01

Unplanned releases of radioactive and hazardous wastes have occurred at the 241-SX Tank Farm on the U.S. Department of Energy Hanford Site in southeast Washington State. Interim and long-term mitigation efforts are currently under evaluation for 241-SX Tank Farm. Two contiguous interim surface barriers have been designed for deployment at 241-SX Tank Farm to reduce future moisture infiltration; however, construction of the surface barriers has been deferred to allow testing of alternative technologies for soil moisture reduction and possibly contaminant source term reduction. Previous tests performed by other organizations at the Hanford Site have demonstrated that: vadose zone desiccation using large diameter (greater than 4 inch) boreholes is feasible; under certain circumstances, mobile contaminants may be removed in addition to water vapor; and small diameter (approximately 2 inch) boreholes (such as those placed by the direct push hydraulic hammer) can be used to perform vapor extractions. Evaluation of the previous work combined with laboratory test results have led to the design of a field proof-of-principle test to remove water and possibly mobile contaminants at greater depths, using small boreholes placed with the direct push unit. (authors)

A vadose zone water fluxmeter with divergence control

Science.gov (United States)

Gee, G.W.; Ward, A.L.; Caldwell, T.G.; Ritter, J.C.

2002-01-01

Unsaturated water flux densities are needed to quantify water and contaminant transfer within the vadose zone. However, water flux densities are seldom measured directly and often are predicted with uncertainties of an order or magnitude or more. A water fluxmeter was designed, constructed, and tested to directly measure drainage fluxes in field soils. The fluxmeter was designed to minimize divergence. It concentrates flow into a narrow sensing region filled with a fiberglass wick. The wick applies suction, proportional to its length, and passively drains the meter. The meter can be installed in an augured borehole at almost any depth below the root zone. Water flux through the meter is measured with a self‐calibrating tipping bucket, with a sensitivity of ∼4 mL tip−1. For our meter this is equivalent to detection limit of ∼0.1 mm. Passive‐wick devices previously have not properly corrected for flow divergence. Laboratory measurements supported predictions of a two‐dimensional (2‐D) numerical model, which showed that control of the collector height H and knowledge of soil hydraulic properties are required for improving divergence control, particularly at fluxes below 1000 mm yr−1. The water fluxmeter is simple in concept, is inexpensive, and has the capability of providing continuous and reliable monitoring of unsaturated water fluxes ranging from less than 1 mm yr−1 to more than 1000 mm yr−1.

simulation of vertical water flow through vadose zone

African Journals Online (AJOL)

HOD

Simulation of vertical water flow representing the release of water from the vadose zone to the aquifer of surroundings ... ground water pollution from agricultural, industrial and municipal .... Peak Flow Characteristics of Wyoming. Streams: US ...

Solute travel time in the vadose zone under RWMC at INEL

International Nuclear Information System (INIS)

Liou, J.C.P.; Tian, J.

1995-01-01

Solute transport in the vadose zone under the Radioactive Waste Management Complex (RWMC) at the Idaho National Engineering Laboratory (INEL) is considered. The objective is to assess the relative importance of variables involved in modeling the travel time of a conservative solute from ground surface to water table. The vadose zone under RWMC is composed of several layers of basalt flows interceded with sediment layers. The thickness of the layers varies with location. The hydraulic properties also vary. The extents of the variations are large, with standard deviations exceed mean in some instances. The vadose zone is idealized as composed of horizontal layers. Solute transport starts at the ground surface and moves vertically downwards to the water table. The perceived process is one-dimensional. This study used VS2DT, a computer code developed by the US Geological Survey, for simulating solute transport in variably saturated porous media

Foam - novel delivery technology for remediation of vadose zone environments - 59019

International Nuclear Information System (INIS)

Jansik, Danielle; Wellman, Dawn M.; Mattigod, Shas V.; Zhong, Lirong; Zhang, Fred; Foote, Martin; Wu, Yuxin; Hubbard, Susan

2012-01-01

Deep vadose zone environments can be a primary source and pathway for contaminant migration to groundwater. These environments present unique characterization and remediation challenges that necessitate scrutiny and research. The thickness, depth, and intricacies of the deep vadose zone, combined with a lack of understanding of the key subsurface processes (e.g., biogeochemical and hydrologic) affecting contaminant migration, make it difficult to create validated conceptual and predictive models of subsurface flow dynamics and contaminant behavior across multiple scales. These factors also make it difficult to design and deploy sustainable remedial approaches and monitor long-term contaminant behavior after remedial actions. Functionally, methods for addressing contamination must remove and/or reduce transport of contaminants. This problem is particularly challenging in the arid western United States where the vadose zone is hundreds of feet thick, rendering transitional excavation methods exceedingly costly and ineffective. Delivery of remedial amendments is one of the most challenging and critical aspects for all remedy-based approaches. The conventional approach for delivery is through injection of aqueous remedial solutions. However, heterogeneous deep vadose zone environments present hydrologic and geochemical challenges that limit the effectiveness. Because the flow of solution infiltration is dominantly controlled by gravity and suction, injected liquid preferentially percolates through highly permeable pathways, by-passing low-permeability zones that frequently contain the majority of contamination. Moreover, the wetting front can readily mobilize and enhance contaminant transport to the underlying aquifer prior to stabilization. Development of innovative in-situ technologies may be the only means to meet remedial action objectives and long-term stewardship goals. Surfactants can be used to lower the liquid surface tension and create stabile foams, which

Enhanced phytoremediation in the vadose zone: Modeling and column studies

Science.gov (United States)

Sung, K.; Chang, Y.; Corapcioglu, M.; Cho, C.

2002-05-01

Phytoremediation is a plant-based technique with potential for enhancing the remediation of vadoese zone soils contaminated by pollutants. The use of deep-rooted plants is an alternative to conventional methodologies. However, when the phytoremediation is applied to the vadose zone, it might have some restrictions since it uses solely naturally driven energy and mechanisms in addition to the complesxity of the vadose zone. As a more innovative technique than conventional phytoremediation methods, air injected phytoremediation technique is introduced to enhance the remediation efficiency or to apply at the former soil vapor extraction or bio venting sites. Effects of air injection, vegetation treatment, and air injection with vegetation treatments on the removal of hydrocarbon were investigated by column studies to simulate the field situation. Both the removal efficiency and the microbial activity were highest in air-injected and vegetated column soils. It was suggested that increased microorganisms activity stimulated by plant root exudates enhanced biodegradation of hydrocarbon compounds. Air injection provided sufficient opportunity for promoting the microbial activity at depths where the conditions are anaerobic. Air injection can enhance the physicochemical properties of the medium and contaminant and increase the bioavailability i.e., the plant and microbial accessibility to the contaminant. A mathematical model that can be applied to phytoremediation, especially to air injected phytoremediation, for simulating the fate and the transport of a diesel contaminant in the vadose zone is developed. The approach includes a two-phase model of water flow in vegetated and unplanted vadose zone soil. A time-specific root distribution model and a microbial growth model in the rhizosphere of vegetated soil were combined with an unsaturated soil water flow equation as well as with a contaminant transport equation. The proposed model showed a satisfactory representation of

Notice of Construction for Tank Waste Remediation System Vadose Zone Characterization

Energy Technology Data Exchange (ETDEWEB)

HILL, J.S.

2000-03-08

200-East and 200-West Areas of the Hanford Site. Vadose zone characterization activities include the drilling and sampling of soil from the surface to the depth of groundwater. Boreholes that are drilled to groundwater will be extended into the aquifer a sufficient distance to enable a groundwater sample to be collected. Under extenuating circumstances it may be prudent to complete these characterization boreholes as groundwater monitoring wells.

Notice of Construction for Tank Waste Remediation System Vadose Zone Characterization

Energy Technology Data Exchange (ETDEWEB)

HILL, J.S.

2000-04-20

-East and 200-West Areas of the Hanford Site. Vadose zone characterization activities include the drilling and sampling of soil from the surface to the depth of groundwater. Boreholes that are drilled to groundwater will be extended into the aquifer a sufficient distance to enable a groundwater sample to be collected. Under extenuating circumstances it may be prudent to complete these characterization boreholes as groundwater monitoring wells.

Vadose Zone Infiltration Rates from Sr isotope Measurements

Science.gov (United States)

Maher, K.; Maher, K.; DePaolo, D. J.; DePaolo, D. J.; Conrad, M.

2001-12-01

Predicting infiltration rates and recharge through the vadose zone in arid regions is difficult and hence developing methods for the measurement of infiltration rates is important. We have been investigating the use of Sr isotope measurements for determining infiltration at the 200 Area plateau on the Hanford reservation in central Washington. In this context, infiltration affects the transport of contaminants to the water table as well as recharge of the groundwater system. Using Sr isotopes for this purpose requires drill core and water samples from the vadose zone, although leaches of the cores can substitute for water samples. Complementary information, including some constraints on regional recharge, can also be obtained using water samples from groundwater monitoring wells. The VZ method is based on the fact that the Sr isotope ratio of soil water just below the surface is often set by dissolution of aeolian material including carbonate, and this ratio is different from the average value in the deeper underlying vadose zone rock matrix. As water infiltrates, the Sr isotopic composition of the water changes toward the rock values as a result of Sr released from the rocks by weathering reactions. The rate of change with depth of the Sr isotope ratio of the vadose zone water is a function ultimately of q/R; the ratio of the infiltration flux (q) to the bulk rock weathering rate (R). Where it is possible to evaluate R, q can be estimated. As data accumulate it may be possible to improve the calibration of the method. At Hanford the vadose zone rock material is mostly unconsolidated sand, silt, and gravel of broadly granitic composition, which constitute the Hanford and Ringold formations. Annual precipitation is about 160 mm/yr. Drilling and coring of a ca. 70m hole to the water table in 1999 as part of the Hanford groundwater monitoring program, in a relatively undisturbed area of the site, allowed us to generate a unique Sr isotope data set. The Sr isotope

Characterization of Vadose Zone Sediment: RCRA Borehole 299-E33-338 Located Near the B-BX-BY Waste Management Area

Energy Technology Data Exchange (ETDEWEB)

Lindenmeier, Clark W.; Serne, R. Jeffrey; Bjornstad, Bruce N.; Gee, Glendon W.; Schaef, Herbert T.; Lanigan, David C.; Lindberg, Michael J.; Clayton, Ray E.; Legore, Virginia L.; Kutnyakov, Igor V.; Baum, Steven R.; Geiszler, Keith N.; Brown, Christopher F.; Valenta, Michelle M.; Vickerman, Tanya S.; Royack, Lisa J.

2008-09-11

This report was revised in September 2008 to remove acid-extractable sodium data from Table 4.8. The sodium data was removed due to potential contamination introduced during the acid extraction process. The rest of the text remains unchanged from the original report issued in June 2003. The overall goals of the of the Tank Farm Vadose Zone Project, led by CH2M HILL Hanford Group, Inc., are: 1) to define risks from past and future single-shell tank farm activities, 2) to identify and evaluate the efficacy of interim measures, and 3) to aid via collection of geotechnical information and data, future decisions that must be made by the U.S. Department of Energy (DOE) regarding the near-term operations, future waste retrieval, and final closure activities for the single-shell tank waste management areas. For a more complete discussion of the goals of the Tank Farm Vadose Zone Project, see the overall work plan, Phase 1 RCRA Facility Investigation/Corrective Measures Study Work Plan for the Single-Shell Tank Waste Management Areas (DOE 1999). Specific details on the rationale for activities performed at the B-BX-BY tank farm waste management area are found in CH2M HILL (2000).

Vadose zone investigations at the Lawrence Livermore National Laboratory Superfund Site: An overview

International Nuclear Information System (INIS)

Iovenitti, J.L.; Nitao, J.J.; Bishop, D.J.

1992-09-01

Lawrence Livermore National Laboratory (LLNL)is investigating the fate and transport of vadose zone contaminants at their Livermore site in Livermore, California. The principal objectives of this work are to identify potential source areas at the Livermore site which require remediation, to prioritize those areas, and finally, to optimize the remediation process. Primary contaminants of interest for this investigation are volatile organic compounds (VOCs) and tritium. A fully integrated, three-part program, consisting of quantitative modeling, field studies, and laboratory measurements, is in progress. To evaluate and predict vadose zone contaminant migration, quantitative modeling is used. Our modeling capabilities are being enhanced through the development of a multicomponent,three-dimensional,nonaqueous phase liquid-liquid-vapor,nonisothermal flow and transport computer code. This code will be also used to evaluate vadose zone remediation requirements. Field studies to acquire LLNL site-specific soil (sediment) characteristics for computer code calibration and validation include subsurf ace lithologic and contaminant profiling, in situ soil moisture content, ground surface emission flux of VOCs and tritium, transpiration of tritium, and ground surface evapotranspiration of water. Multilevel vadose zone monitoring devices are used to monitor the gaseous and aqueous transport of contaminants

Simulation of water seepage through a vadose zone in fractured rock

International Nuclear Information System (INIS)

Fuentes, Nestor O.

2003-01-01

In order to improve our understanding of the vadose zone in fractured rock, obtaining useful tools to simulate, predict and prevent subsurface contamination, a three-dimensional model has been developed from the base of recent two-dimensional codes. Fracture systems are simulated by means of a dynamical evolution of a random-fuse network model, and the multiphase expression of Richards equation is used to describe fluid displacements. Physical situations presented here emphasized the importance of fracture connectivity and spatial variability on the seepage evolution through the vadose zone, and confirm the existence of dendritic patterns along localized preferential paths. (author)

A modeling study of water flow in the vadose zone beneath the Radioactive Waste Management Complex

International Nuclear Information System (INIS)

Baca, R.G.; Magnuson, S.O.; Nguyen, H.D.; Martian, P.

1992-01-01

A modeling study was conducted for the purpose of gaining insight into the nature of water flow in the vadose zone beneath the Radioactive Waste Management Complex (RWMC). The modeling study focused on three specific hydrologic aspects: (1) relationship between meteorologic conditions and net infiltration, (2) water movement associated with past flooding events, and (3) estimation of water travel-times through the vadose zone. This information is necessary for understanding how contaminants may be transported through the vadose zone. Evaluations of net infiltration at the RWMC were performed by modeling the processes of precipitation, evaporation, infiltration and soil-moisture redistribution. Water flow simulations were performed for two distinct time periods, namely 1955--1964 and 1984--1990. The patterns of infiltration were calculated for both the undisturbed (or natural sediments) and the pit/trench cover materials. Detailed simulations of the 1969 flooding of Pit 10 were performed to estimate the rate and extent of water movement through the vadose zone. Water travel-times through the vadose zone were estimated using a Monte Carlo simulation approach. The simulations accounted for variability of soil and rock hydraulic properties as well as variations in the infiltration rate

Characterization of Vadose Zone Sediments Below the TX Tank Farm: Probe Holes C3830, C3831, C3832 and 299-W10-27

Energy Technology Data Exchange (ETDEWEB)

Serne, R JEFFREY.; Bjornstad, Bruce N.; Horton, Duane G.; Lanigan, David C.; Lindenmeier, Clark W.; Lindberg, Michael J.; Clayton, Ray E.; LeGore, Virginia L.; Orr, Robert D.; Kutnyakov, Igor V.; Baum, Steven R.; Geiszler, Keith N.; Valenta, Michelle M.; Vickerman, Tanya S.

2004-04-01

Pacific Northwest National Laboratory performed detailed analyses on vadose zone sediments from within Waste Management Area T-TX-TY. This report contains all the geologic, geochemical, and selected physical characterization data collected on vadose zone sediment recovered from three probe holes (C3830, C3831, and C3832) in the TX Tank Farm, and from borehole 299-W-10-27. Sediments from borehole 299-W-10-27 are considered to be uncontaminated sediments that can be compared with contaminated sediments. This report also presents our interpretation of the sediment lithologies, the vertical extent of contamination, the migration potential of the contaminants, and the likely source of the contamination in the vadose zone and groundwater below the TX Tank Farm. Sediment from the probe holes was analyzed for: moisture, radionuclide and carbon contents;, one-to-one water extracts (soil pH, electrical conductivity, cation, trace metal, and anion data), and 8 M nitric acid extracts. Overall, our analyses showed that common ion exchange is a key mechanism that influences the distribution of contaminants within that portion of the vadose zone affected by tank liquor. We did not observe significant indications of caustic alteration of the sediment mineralogy or porosity, or significant zones of slightly elevated pH values in the probe holes. The sediments do show that sodium-, nitrate-, and sulfate-dominated fluids are present. The fluids are more dilute than tank fluids observed below tanks at the SX and BX Tank Farms. Three primary stratigraphic units were encountered in each probe hole: (1) backfill material, (2) the Hanford formation, and (3) the Cold Creek unit. Each of the probe holes contain thin fine-grained layers in the Hanford H2 stratigraphic unit that may impact the flow of leaked fluids and effect irregular and horizontal flow. The probe holes could not penetrate below the enriched calcium carbonate strata of the Cold Creek lower subunit; therefore, we did not

Deep Vadose Zone-Applied Field Research Initiative Fiscal Year 2011 Annual Report

International Nuclear Information System (INIS)

Wellman, Dawn M.; Johnson, Timothy C.; Smith, Ronald M.; Truex, Michael J.; Matthews, Hope E.

2011-01-01

This annual report describes the background of the Deep Vadose Zone-Applied Field Research Initiative, and some of the programmatic approaches and transformational technologies in groundwater and deep vadose zone remediation developed during fiscal year 2011. The Department of Energy (DOE) Office of Technology Innovation and Development's (OTID) mission is to transform science into viable solutions for environmental cleanup. In 2010, OTID developed the Impact Plan, Science and Technology to Reduce the Life Cycle Cost of Closure to outline the benefits of research and development of the lifecycle cost of cleanup across the DOE complex. This plan outlines OTID's ability to reduce by $50 billion, the $200 billion life-cycle cost in waste processing, groundwater and soil, nuclear materials, and deactivation and decommissioning. The projected life-cycle costs and return on investment are based on actual savings realized from technology innovation, development, and insertion into remedial strategies and schedules at the Fernald, Mound, and Ashtabula sites. To achieve our goals, OTID developed Applied Field Research Initiatives to facilitate and accelerate collaborative development and implementation of new tools and approaches that reduce risk, cost and time for site closure. The primary mission of the Deep Vadose Zone-Applied Field Research Initiative (DVZ-AFRI) is to protect our nation's water resources, keeping them clean and safe for future generations. The DVZ-AFRI was established for the DOE to develop effective, science-based solutions for remediating, characterizing, monitoring, and predicting the behavior and fate of deep vadose zone contamination. Subsurface contaminants include radionuclides, metals, organics, and liquid waste that originated from various sources, including legacy waste from the nation's nuclear weapons complexes. The DVZ-AFRI project team is translating strategy into action by working to solve these complex challenges in a collaborative

DOE capabilities for in-situ characterization and monitoring of formation properties in the vadose zone

International Nuclear Information System (INIS)

Hearst, J.R.; Brodeur, J.R.; Koizumi, C.J.; Conaway, J.G.; Mikesell, J.L.; Nelson, P.H.; Stromswold, D.C.; Wilson, R.D.

1993-09-01

The DOE Environmental Restoration (ER) Program faces the difficult task of characterizing the properties of the subsurface and identifying and mapping a large number of contaminants at landfills, surface disposal areas, spill sites, nuclear waste tanks, and subsurface contaminant plumes throughout the complex of DOE facilities. Geophysical borehole logs can measure formation properties such as bulk density, water content, and lithology, and can quantitatively analyze for radionuclides and such elements as chlorine and heavy metals. Since these measurements can be replaced as desired, they can be used for both initial characterization and monitoring of changes in contaminant concentration and water content (sometimes linked to contaminant migration), at a fraction of the cost of conventional sampling. The techniques develop at several DOE laboratories, and the experience that the authors have gained in making in-situ measurements in the vadose zone, are applicable to problems at many other DOE sites. Moreover, they can capitalize on existing inventories of boreholes. By building on this experience workers involved in ER projects at those sites should be able to obtain high-quality data at substantial reductions in cost and time

Wildfire effects on vadose zone hydrology in forested boreal peatland microforms

Science.gov (United States)

Thompson, Dan K.; Waddington, James M.

2013-04-01

SummaryPeatland vulnerability to wildfire disturbance has been shown to vary as a function of hummock and hollow microforms and vadose zone hydrology, with low-lying hollow microforms most susceptible to deep combustion of peat. To better understand how this microform induced pattern of burning alters vadose water storage, pore-water pressure, and water table relationships, we examined a paired burned and unburned peatland in the boreal plain region of north central Alberta. Water table response to rain events increased significantly after wildfire, resulting in a more variable unsaturated zone thickness that was more responsive to smaller rain events. Water storage losses in the vadose zone occurred primarily at depths greater than 15 cm. Large peat surface water loss occurred in hummock microforms in the early spring due to the presence of unsaturated frozen peat at depth, likely a result of a vapour gradient from the unfrozen peat into the frozen peat underneath. During this period, the loss of water storage in the vadose zone satisfied up to 25% of daily evaporative demand, compared to only 3-5% during ice-free periods. A similar but less severe drying was observed late in summer, with burned hummocks the most vulnerable with high pore-water pressures. The enhanced surface drying observed is a precursor to high pore-water pressure conditions that inhibit Sphagnum regeneration. Our observations point to a paradox where the hummocks, being most resistant to combustion, are themselves most prone to high pore-water pressures following wildfire. The harsher hummock environment may contribute to the observed delay in post-fire Sphagnum regeneration in hummocks compared to hollows.

High Frequency Electromagnetic Impedance Imaging for Vadose Zone and Groundwater Characterization

International Nuclear Information System (INIS)

Newman, Greory A.; Alumbaugh, David L.; Hoversten, Michael; Nichols, Edward

2003-01-01

A geophysical experiment is described for characterizing the clastic dike systems, which are ubiquitous within the vadose zone at the Hanford Nuclear Reservation. because the dikes possess a significant electrical contrast from the insulating host medium, we have applied controlled source audio magnetotelluric (CSAMT) measurements to map their geometric extent and to further clarify if the dike complex acts as a conduit for contaminant transport within the vadose zone. Because of cost and weak natural field signal levels, we employed controlled field sourcing using the STRATGEM acquisition system. Use of artificial fields often goes with the assumption that the data required in the far-field of the transmitter

Deep Vadose Zone Characterization at the Hanford Site: Accomplishments from the Last Ten Years

International Nuclear Information System (INIS)

Brown, Christopher F.; Serne, R. Jeffrey

2008-01-01

The overall goal of the Tank Farm Vadose Zone Project, led by CH2M HILL Hanford Group, Inc., is to define risks from past and future single-shell tank farm activities at Hanford. To meet this goal, CH2M HILL Hanford Group, Inc. tasked scientists from Pacific Northwest National Laboratory (PNNL) to perform detailed analyses on vadose zone sediments collected within/adjacent to the twelve single-shell tank farms contained within Hanford's Central Plateau region. This work has been performed under the Resource Conservation and Recovery Act (RCRA) Corrective Action Program and is associated with the Hanford Federal Facility Agreement and Consent Order. While there are many facets to the laboratory studies employed by PNNL, the four primary objectives of this work are to: identify the type and quantity of contamination present, understand the physical processes that affect the transport of contaminants in the vadose zone sediments, when practical, identify the source(s) of the contamination found in the sediment samples, and when practical, determine if a link can be made between the vadose zone contamination observed and any known groundwater contaminants in the vicinity. Since its inception in 1997, PNNL's Vadose Zone Characterization Project has evolved to better meet these four key objectives. The single-largest adaptation of the Vadose Zone Characterization Project over its ten years of operation was the advent of a tiered sample analysis approach. Use of a tiered approach allows resources to be focused on those samples/tests that provide the largest amount of scientific information to best meet the four key project objectives within the budget available. Another significant, but more recent, adaptation has been the implementation of a rapid turnaround characterization process in which sediment samples are analyzed in near real-time to aid drilling activities within the tank farms. This paper highlights details of the characterization activities performed as well

200-UP-1 Operable Unit borehole summary report for FY 1995

International Nuclear Information System (INIS)

Darrach, M.E.

1996-07-01

This report details the well construction, sampling, analyses, and geologic character of the Ringold Formation as it was encountered in five wells drilled in the 200-UP-1 Operable Unit during fiscal year (FY) 1995. The 200-UP-1 Interim Remedial Measure Drilling Description of Work was prepared to support the FY 95 field work and presented the specific field activities and procedural requirements to be implemented. The geology of the vadose zone is not described in the text of this report. Vadose zone geology in the immediate area is characterized in sufficient detail in existing documents. However, the borehole logs and well summary sheets provided in the appendices depict the vadose zone stratigraphy and well construction details. Sieve analyses conducted on sediments from the saturated zone were used to design the well completions; these analyses are included. Where applicable, inferences are made concerning the geologic character of the saturated interval. In addition, a synopsis of the preliminary well development process is outlined. Other related information is included with this report as supplemental data

Groundwater/Vadose Zone Integration Project Management Plan

International Nuclear Information System (INIS)

Hughes, M. C.

1999-01-01

This Project Management Plan (PMP) defines the authorities, roles, and responsibilities of the US Department of Energy (DOE), Richland Operations Office (RL) and those contractor organizations participating in the Hanford Site' s Groundwater/Vadose Zone (GW/VZ) Integration Project. The PMP also describes the planning and control systems, business processes, and other management tools needed to properly and consistently conduct the Integration Project scope of work

Transport and degradation of contaminants in the vadose zone

NARCIS (Netherlands)

Schotanus, D.

2013-01-01

Leaching of contaminants from the vadose zone to the groundwater depends on the soil properties and the infiltration rate. In this thesis, organic degradable contaminants were studied, such as de-icing chemicals (consisting of propylene glycol, PG) and pesticides. Heterogeneous soil properties

Calibrating vadose zone models with time-lapse gravity data

DEFF Research Database (Denmark)

Christiansen, Lars; Binning, Philip John; Rosbjerg, Dan

2011-01-01

The vadose zone plays an important role in the hydrologic cycle. Various geophysical methods can determine soil water content variations in time and space in volumes ranging from a few cubic centimeters to several cubic meters. In contrast to the established methods, time-lapse gravity measurements...... of changes in soil water content do not rely on a petrophysical relationship between the measured quantity and the water content but give a direct measure of the mass change in the soil. Only recently has the vadose zone been systematically incorporated when ground-based gravity data are used to infer...... hydrologic information. In this study, changes in the soil water content gave rise to a measurable signal in a forced infiltration experiment on a 107-m2 grassland area. Time-lapse gravity data were able to constrain the van Genuchten soil hydraulic parameters in both a synthetic example and a field...

Radiotracer technique to study pollutant behavior in the vadose zone for groundwater protection

International Nuclear Information System (INIS)

Kulkarni, U.P.; Sinha, U.K.; Navada, S.V.; Datta, P.S.; Sud, Y.K.; Kulkarni, K.M.; Aggrawal, P.; )

2004-01-01

Pollutants are generated either by industrial or agricultural activity. Pollutants produced due to industrial activities fall into point source category and those generated from agricultural are grouped into extended source category. Under an International Atomic Energy Agency/Coordinated Research Program study, emphasis has been given on transport of pollutants, generated from agricultural activities, in particular, due to the application of fertilizer inputs to a variety of crops. Pollutants take entry through the vadose zone and ultimately join the saturated zone. Once groundwater is polluted it is rather difficult or impossible to take remedial measures for groundwater protection. Groundwater being an important natural resource, it is important to protect it from getting polluted. It is hence essential to have a clear understanding of the complex processes (physical, biological and chemical etc.) undergoing in the unsaturated zone. Radiotracers give good insight about the pollutant behavior in the vadose zone. Tritiated water and 60 Co (a gamma emitting tracer in the cyanide complex form) were used as tracers and were injected at 60 cm depth in the vadose zone of IARI farm for pollutant transport study. Tritium and 60 Co tracer displacements were measured by liquid scintillation and sodium iodide scintillation method respectively. It was found that the tritium tracer moved up to 2.4 meters in six months and part of the tritium tracer was exchanged with immobile water in the soil, as three distinct peaks were observed in tritium profile. 60 Co and tritium tracers were found to move with the same velocity in the vadose zone. These tracer studies indicate that the pollutants may reach the groundwater in about three years. (author)

Evaluating Contaminant Flux from the Vadose Zone to the Groundwater in the Hanford Central Plateau. SX Tank Farms Case Study

Energy Technology Data Exchange (ETDEWEB)

Truex, Michael J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Oostrom, Martinus [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Last, George V. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Strickland, Christopher E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Tartakovsky, Guzel D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2015-09-01

At the DOE Hanford Site, contaminants were discharged to the subsurface through engineered waste sites in the Hanford Central Plateau. Additional waste was released through waste storage tank leaks. Much of the contaminant inventory is still present within the unsaturated vadose zone sediments. The nature and extent of future groundwater contaminant plumes and the growth or decline of current groundwater plumes beneath the Hanford Central Plateau are a function of the contaminant flux from the vadose zone to the groundwater. In general, contaminant transport is slow through the vadose zone and it is difficult to directly measure contaminant flux in the vadose zone. Predictive analysis, supported by site characterization and monitoring data, was applied using a structured, systems-based approach to estimate the future contaminant flux to groundwater in support of remediation decisions for the vadose zone and groundwater (Truex and Carroll 2013). The SX Tank Farm was used as a case study because of the existing contaminant inventory in the vadose zone, observations of elevated moisture content in portions of the vadose zone, presence of a limited-extent groundwater plume, and the relatively large amount and wide variety of data available for the site. Although the SX Tank Farm case study is most representative of conditions at tank farm sites, the study has elements that are also relevant to other types of disposal sites in the Hanford Central Plateau.

Preface: Research advances in vadose zone hydrology through simulations with the TOUGH codes

International Nuclear Information System (INIS)

Finsterle, Stefan; Oldenburg, Curtis M.

2004-01-01

Numerical simulators are playing an increasingly important role in advancing our fundamental understanding of hydrological systems. They are indispensable tools for managing groundwater resources, analyzing proposed and actual remediation activities at contaminated sites, optimizing recovery of oil, gas, and geothermal energy, evaluating subsurface structures and mining activities, designing monitoring systems, assessing the long-term impacts of chemical and nuclear waste disposal, and devising improved irrigation and drainage practices in agricultural areas, among many other applications. The complexity of subsurface hydrology in the vadose zone calls for sophisticated modeling codes capable of handling the strong nonlinearities involved, the interactions of coupled physical, chemical and biological processes, and the multiscale heterogeneities inherent in such systems. The papers in this special section of ''Vadose Zone Journal'' are illustrative of the enormous potential of such numerical simulators as applied to the vadose zone. The papers describe recent developments and applications of one particular set of codes, the TOUGH family of codes, as applied to nonisothermal flow and transport in heterogeneous porous and fractured media (http://www-esd.lbl.gov/TOUGH2). The contributions were selected from presentations given at the TOUGH Symposium 2003, which brought together developers and users of the TOUGH codes at the Lawrence Berkeley National Laboratory (LBNL) in Berkeley, California, for three days of information exchange in May 2003 (http://www-esd.lbl.gov/TOUGHsymposium). The papers presented at the symposium covered a wide range of topics, including geothermal reservoir engineering, fracture flow and vadose zone hydrology, nuclear waste disposal, mining engineering, reactive chemical transport, environmental remediation, and gas transport. This Special Section of ''Vadose Zone Journal'' contains revised and expanded versions of selected papers from the

A Catalog of Vadose Zone Hydraulic Properties for the Hanford Site

Energy Technology Data Exchange (ETDEWEB)

Freeman, Eugene J.; Khaleel, Raziuddin; Heller, Paula R.

2001-09-24

The purpose of this catalog is to integrate all available soil physics data and information from vadose zone characterization and performance assessments into one useable, scientifically defensible document.

Calculation of unmitigated release from reverse circulation drilling of a borehole three meters south of borehole 41-15-09 near SST 241-SX-115

International Nuclear Information System (INIS)

SCOTT, D.L.

1999-01-01

To more fully characterize the vadose zone near Single Shell Tank 241-SX-115, another borehole will be drilled and sampled by using reverse circulation drilling equipment. Compressed air propels the drill and sweeps out cuttings. Dose calculations in this document are performed for an unmitigated airborne release from the drill string. Doses were found not to exceed TWRS risk guideline values

CMI Remedy Selection for HE- and Barium-Contaminated Vadose Zone and Alluvium at LANL

Science.gov (United States)

Hickmott, D.; Reid, K.; Pietz, J.; Ware, D.

2008-12-01

A high explosives (HE) machining building outfall at Los Alamos National Laboratory's Technical Area 16 discharged millions of gallons of HE- and barium-contaminated water into the Canon de Valle watershed. The effluent contaminated surface soils, the alluvial aquifer, vadose zone waters, and deep-perched and regional groundwaters with HE and barium, frequently at levels greater than regulatory standards. Site characterization studies began in 1995 and included extensive monitoring of surface water, groundwater, soils, and subsurface solid media. Hydrogeologic and geophysical studies were conducted to help understand contaminant transport mechanisms and pathways. Results from the characterization studies were used to develop a site conceptual model. In 2000 the principal source area was removed. The ongoing Corrective Measure Study (CMS) and Corrective Measure Implementation (CMI) focus on residual vadose zone contamination and on the contaminated alluvial system. Regulators recently selected a CMI remedy that combined: 1) augmented source removal; 2) grouting of an HE- contaminated surge bed; 3) deployment of Stormwater Management System (SMS) stormfilters in contaminated springs; and 4) permeable reactive barriers (PRBs) in contaminated alluvium. The hydrogeologic conceptual model for the vadose zone and alluvial system as well as the status of the canyon as habitat for the Mexican Spotted Owl were key factors in selection of these minimal-environmental-impact remedies. The heterogeneous vadose zone, characterized by flow and contaminant transport in fractures and in surge beds, requires contaminant treatment at a point of discharge. The canyon PRB is being installed to capture water and contaminants prior to infiltration into the vadose zone. Pilot-scale testing of the SMS and lab-scale batch and column tests of a range of media suggest that granular activated carbon, zeolite, and gypsum may be effective media for removal of HE and/or barium from contaminated

The Mojave vadose zone: a subsurface biosphere analogue for Mars.

Science.gov (United States)

Abbey, William; Salas, Everett; Bhartia, Rohit; Beegle, Luther W

2013-07-01

If life ever evolved on the surface of Mars, it is unlikely that it would still survive there today, but as Mars evolved from a wet planet to an arid one, the subsurface environment may have presented a refuge from increasingly hostile surface conditions. Since the last glacial maximum, the Mojave Desert has experienced a similar shift from a wet to a dry environment, giving us the opportunity to study here on Earth how subsurface ecosystems in an arid environment adapt to increasingly barren surface conditions. In this paper, we advocate studying the vadose zone ecosystem of the Mojave Desert as an analogue for possible subsurface biospheres on Mars. We also describe several examples of Mars-like terrain found in the Mojave region and discuss ecological insights that might be gained by a thorough examination of the vadose zone in these specific terrains. Examples described include distributary fans (deltas, alluvial fans, etc.), paleosols overlain by basaltic lava flows, and evaporite deposits.

Second ILAW Site Borehole Characterization Plan

International Nuclear Information System (INIS)

Reidel, S.P.

2000-01-01

The US Department of Energy's Hanford Site has the most diverse and largest amounts of radioactive tank waste in the US. High-level radioactive waste has been stored at Hanford since 1944. Approximately 209,000 m 3 (54 Mgal) of waste are currently stored in 177 tanks. Vitrification and onsite disposal of low-activity tank waste (LAW) are embodied in the strategy described in the Tri-Party Agreement. The tank waste is to be retrieved, separated into low- and high-level fractions, and then immobilized. The low-activity vitrified waste will be disposed of in the 200 East Area of the Hanford Site. This report is a plan to drill and characterize the second borehole for the Performance Assessment. The first characterization borehole was drilled in 1998. The plan describes data collection activities for determining physical and chemical properties of the vadose zone and saturated zone on the northeast side of the proposed disposal site. These data will then be used in the 2005 Performance Assessment

Tank waste remediation system vadose zone program plan

International Nuclear Information System (INIS)

Fredenburg, E.A.

1998-01-01

The objective of the vadose zone characterization under this program is to develop a better conceptual geohydrologic model of identified tank farms which will be characterized so that threats to human health and the environment from past leaks and spills, intentional liquid discharges, potential future leaks during retrieval, and from residual contaminants that may remain in tank farms at closure can be explicitly addressed in decision processes. This model will include geologic, hydrologic, and hydrochemical parameters as defined by the requirements of each of the TWRS programs identified here. The intent of this TWRS Vadose Zone Program Plan is to provide justification and an implementation plan for the following activities: Develop a sufficient understanding of subsurface conditions and transport processes to support decisions on management, cleanup, and containment of past leaks, spills, and intentional liquid discharges; Develop a sufficient understanding of transport processes to support decisions on controlling potential retrieval leaks; Develop a sufficient understanding of transport processes to support decisions on tank farm closure, including allowable residual waste that may remain at closure; and Provide new information on geotechnical properties in the 200 Area to supplement data used for design and performance assessment for immobilized low-activity waste disposal facilities

Tank waste remediation system vadose zone program plan

Energy Technology Data Exchange (ETDEWEB)

Fredenburg, E.A.

1998-07-27

The objective of the vadose zone characterization under this program is to develop a better conceptual geohydrologic model of identified tank farms which will be characterized so that threats to human health and the environment from past leaks and spills, intentional liquid discharges, potential future leaks during retrieval, and from residual contaminants that may remain in tank farms at closure can be explicitly addressed in decision processes. This model will include geologic, hydrologic, and hydrochemical parameters as defined by the requirements of each of the TWRS programs identified here. The intent of this TWRS Vadose Zone Program Plan is to provide justification and an implementation plan for the following activities: Develop a sufficient understanding of subsurface conditions and transport processes to support decisions on management, cleanup, and containment of past leaks, spills, and intentional liquid discharges; Develop a sufficient understanding of transport processes to support decisions on controlling potential retrieval leaks; Develop a sufficient understanding of transport processes to support decisions on tank farm closure, including allowable residual waste that may remain at closure; and Provide new information on geotechnical properties in the 200 Area to supplement data used for design and performance assessment for immobilized low-activity waste disposal facilities.

TREATABILITY TEST PLAN FOR DEEP VADOSE ZONE REMEDIATION AT THE HANFORD'S SITE CENTRAL PLATEAU

International Nuclear Information System (INIS)

PETERSEN SW; MORSE JG; TRUEX MJ; LAST GV

2007-01-01

A treatability test plan has been prepared to address options for remediating portions of the deep vadose zone beneath a portion of the U.S. Department of Energy's (DOE's) Hanford Site. The vadose zone is the region of the subsurface that extends from the ground surface to the water table. The overriding objective of the treatability test plan is to recommend specific remediation technologies and laboratory and field tests to support the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 and Resource Conservation and Recovery Act of 1976 remedial decision-making process in the Central Plateau of the Hanford Site. Most of the technologies considered involve removing water from the vadose zone or immobilizing the contaminants to reduce the risk of contaminating groundwater. A multi-element approach to initial treatability testing is recommended, with the goal of providing the information needed to evaluate candidate technologies. The proposed tests focus on mitigating two contaminants--uranium and technetium. Specific technologies are recommended for testing at areas that may affect groundwater in the future, but a strategy to test other technologies is also presented

Description of Work for Borehole Sampling at the 116-DR-1and 116-DR-2 Trenches

International Nuclear Information System (INIS)

Bergstrom, K. A.

1999-01-01

This description of work (DOW) details the sampling and analysis activities for characterizing the deep zone soils below the 116-DR-1and 116-DR-2 trenches, which are located in the 100-DR- 1 Operable Unit (OU), and will serve as a guide for the personnel performing the work. The ''deep zone'' refers to the portion of the vadose zone between the bottom of the waste site and the water table. The scope of work includes drilling a borehole (B8786), sampling vadose zone and upper saturated zone soils at ∼ 1-m intervals, collecting a water sample below the top of the water table, and analyzing the samples for all contaminants of concern (COCs). Specific procedures for defined tasks are covered under the Bechtel Hanford, Inc. (BHI)manual, BHI-EE-01, Environmental Investigations Procedures

Deep Vadose Zone Treatability Test for the Hanford Central Plateau: Interim Post-Desiccation Monitoring Results, Fiscal Year 2014

Energy Technology Data Exchange (ETDEWEB)

Truex, Michael J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Strickland, Christopher E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Johnson, Christian D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Johnson, Timothy C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Clayton, Ray E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Chronister, Glen B. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2014-09-01

Over decades of operation, the U.S. Department of Energy (DOE) and its predecessors have released nearly 2 trillion L (450 billion gal.) of liquid into the vadose zone at the Hanford Site. Much of this discharge of liquid waste into the vadose zone occurred in the Central Plateau, a 200 km² (75 mi²) area that includes approximately 800 waste sites. Some of the inorganic and radionuclide contaminants in the deep vadose zone at the Hanford Site are at depths below the limit of direct exposure pathways, but may need to be remediated to protect groundwater. The Tri-Party Agencies (DOE, U.S. Environmental Protection Agency, and Washington State Department of Ecology) established Milestone M 015 50, which directed DOE to submit a treatability test plan for remediation of technetium-99 (Tc-99) and uranium in the deep vadose zone. These contaminants are mobile in the subsurface environment and have been detected at high concentrations deep in the vadose zone, and at some locations have reached groundwater. Testing technologies for remediating Tc-99 and uranium will also provide information relevant for remediating other contaminants in the vadose zone. A field test of desiccation is being conducted as an element of the DOE test plan published in March 2008 to meet Milestone M 015 50. The active desiccation portion of the test has been completed. Monitoring data have been collected at the field test site during the post-desiccation period and are reported herein. This is an interim data summary report that includes about 3 years of post-desiccation monitoring data. The DOE field test plan proscribes a total of 5 years of post-desiccation monitoring.

Immobilized low-activity waste site borehole 299-E17-21

International Nuclear Information System (INIS)

Reidel, S.P.; Reynolds, K.D.; Horton, D.G.

1998-08-01

The Tank Waste Remediation System (TWRS) is the group at the Hanford Site responsible for the safe underground storage of liquid waste from previous Hanford Site operations, the storage and disposal of immobilized tank waste, and closure of underground tanks. The current plan is to dispose of immobilized low-activity tank waste (ILAW) in new facilities in the southcentral part of 200-East Area and in four existing vaults along the east side of 200-East Area. Boreholes 299-E17-21, B8501, and B8502 were drilled at the southwest corner of the ILAW site in support of the Performance Assessment activities for the disposal options. This report summarizes the initial geologic findings, field tests conducted on those boreholes, and ongoing studies. One deep (480 feet) borehole and two shallow (50 feet) boreholes were drilled at the southwest corner of the ILAW site. The primary factor dictating the location of the boreholes was their characterization function with respect to developing the geohydrologic model for the site and satisfying associated Data Quality Objectives. The deep borehole was drilled to characterize subsurface conditions beneath the ILAW site, and two shallow boreholes were drilled to support an ongoing environmental tracer study. The tracer study will supply information to the Performance Assessment. All the boreholes provide data on the vadose zone and saturated zone in a previously uncharacterized area

Research Plan: Foam Delivery of Remedial Amendments to Deep Vadose Zone for Metals and Radionuclides Remediation

International Nuclear Information System (INIS)

Zhong, Lirong; Hart, Andrea T.; Szecsody, James E.; Zhang, Z.F.; Freedman, Vicky L.; Ankeny, Mark; Hull, Laurence; Oostrom, Martinus; Freshley, Mark D.; Wellman, Dawn M.

2009-01-01

Research proposals were submitted to the Scientific and Technical Basis for In Situ Treatment of Metals and Radionuclides Technical Working Group under the US Department of Energy (DOE) Environmental Management Office (specifically, EM-22). After a peer review and selection process, the proposal, 'Foam Delivery of Remedial Amendments to Deep Vadose Zone for Metals and Radionuclides Remediation,' submitted by Pacific Northwest National Laboratory (PNNL) was selected for support by the program. A research plan was requested for this EM funded project. The overall objective of this project is to develop foam delivery technology for the distribution of remedial amendments to deep vadose zone sediments for in situ immobilization of metal and radionuclide contaminants. The focus of this research in FY 2009 is on the physical aspects of the foam delivery approach. Specific objectives are to (1) study the foam quality (i.e. the gas volume fraction in foam) influence on injection pressure, (2) study the sediment air permeability influence on injection pressure, (3) investigate liquid uptake in sediment and determine whether a water front will be formed during foam delivery, (4) test amendment distance (and mass) delivery by foam from the injection point, (5) study the enhanced sweeping over heterogeneous systems (i.e., low K zones) by foam delivery relative to water-based delivery under vadose zone conditions, and (6) numerically simulate foam delivery processes in the vadose zone. Laboratory scale experiments will be conducted at PNNL to study a range of basic physical aspects of the foam propagation in sediments, including foam quality and sediment permeability influence on injection pressure, liquid uptake, and foam sweeping across heterogeneous systems. This study will be augmented with separate studies to be conducted at MSE Technology Applications, Inc. (MSE) to evaluate foam transport and amendment delivery at the intermediate-scale. The results of intermediate

COLLOID-FACILITATED TRANSPORT OF RADIONUCLIDES THROUGH THE VADOSE ZONE

International Nuclear Information System (INIS)

Flury, Markus

2003-01-01

Contaminants have leaked into the vadose zone at the USDOE Hanford reservation. It is important to understand the fate and transport of these contaminants to design remediation strategies and long-term waste management plans at the Hanford reservation. Colloids may play an important role in fate and transport of strongly sorbing contaminants, such as Cs or Pu. This project seeks to improve the basic understanding of colloid and colloid-facilitated transport of contaminants in the vadose zone. The specific objectives addressed are: (1) Determine the structure, composition, and surface charge characteristics of colloidal particles formed under conditions similar to those occurring during leakage of waste typical of Hanford tank supernatants into soils and sediments surrounding the tanks. (2) Characterize the mutual interactions between colloids, contaminant, and soil matrix in batch experiments under various ionic strength and pH conditions. We will investigate the nature of the solid-liquid interactions and the kinetics of the reactions. (3) Evaluate mobility of colloids through soil under different degrees of water saturation and solution chemistry (ionic strength and pH). (4) Determine the potential of colloids to act as carriers to transport the contaminant through the vadose zone and verify the results through comparison with field samples collected under leaking tanks. (5) Improve conceptual characterization of colloid-contaminant-soil interactions and colloid-facilitated transport for implementation into reactive chemical transport models. This project was in part supported by an NSF-IGERT grant to Washington State University. The IGERT grant provided funding for graduate student research and education, and two graduate students were involved in the EMSP project. The IGERT program also supported undergraduate internships. The project is part of a larger EMSP program to study fate and transport of contaminants under leaking Hanford waste tanks. The project has

Transport and degradation of perchlorate in deep vadose zone: implications from direct observations during bioremediation treatment

Science.gov (United States)

Dahan, Ofer; Katz, Idan; Avishai, Lior; Ronen, Zeev

2017-08-01

An in situ bioremediation experiment of a deep vadose zone ( ˜ 40 m) contaminated with a high concentration of perchlorate (> 25 000 mg L-1) was conducted through a full-scale field operation. Favourable environmental conditions for microbiological reduction of perchlorate were sought by infiltrating an electron donor-enriched water solution using drip irrigation underlying an airtight sealing liner. A vadose zone monitoring system (VMS) was used for real-time tracking of the percolation process, the penetration depth of dissolved organic carbon (DOC), and the variation in perchlorate concentration across the entire soil depth. The experimental conditions for each infiltration event were adjusted according to insight gained from data obtained by the VMS in previous stages. Continuous monitoring of the vadose zone indicated that in the top 13 m of the cross section, perchlorate concentration is dramatically reduced from thousands of milligrams per litre to near-detection limits with a concurrent increase in chloride concentration. Nevertheless, in the deeper parts of the vadose zone (< 17 m), perchlorate concentration increased, suggesting its mobilization down through the cross section. Breakthrough of DOC and bromide at different depths across the unsaturated zone showed limited migration capacity of biologically consumable carbon and energy sources due to their enhanced biodegradation in the upper soil layers. Nevertheless, the increased DOC concentration with concurrent reduction in perchlorate and increase in the chloride-to-perchlorate ratio in the top 13 m indicate partial degradation of perchlorate in this zone. There was no evidence of improved degradation conditions in the deeper parts where the initial concentrations of perchlorate were significantly higher.

Deep Vadose Zone Applied Field Research Center: Transformational Technology Development For Environmental Remediation

International Nuclear Information System (INIS)

Wellman, Dawn M.; Triplett, Mark B.; Freshley, Mark D.; Truex, Michael J.; Gephart, Roy E.; Johnson, Timothy C.; Chronister, Glen B.; Gerdes, Kurt D.; Chamberlain, Skip; Marble, Justin; Ramirez, Rosa

2011-01-01

DOE-EM, Office of Groundwater and Soil Remediation and DOE Richland, in collaboration with the Hanford site and Pacific Northwest National Laboratory, have established the Deep Vadose Zone Applied Field Research Center (DVZ-AFRC). The DVZ-AFRC leverages DOE investments in basic science from the Office of Science, applied research from DOE EM Office of Technology Innovation and Development, and site operation (e.g., site contractors [CH2M HILL Plateau Remediation Contractor and Washington River Protection Solutions], DOE-EM RL and ORP) in a collaborative effort to address the complex region of the deep vadose zone. Although the aim, goal, motivation, and contractual obligation of each organization is different, the integration of these activities into the framework of the DVZ-AFRC brings the resources and creativity of many to provide sites with viable alternative remedial strategies to current baseline approaches for persistent contaminants and deep vadose zone contamination. This cooperative strategy removes stove pipes, prevents duplication of efforts, maximizes resources, and facilitates development of the scientific foundation needed to make sound and defensible remedial decisions that will successfully meet the target cleanup goals for one of DOE EM's most intractable problems, in a manner that is acceptable by regulators.

IMPACT ASSESSMENT OF EXISTING VADOSE ZONE CONTAMINATION AT THE HANFORD SITE SX TANK FARM

International Nuclear Information System (INIS)

KHALEEL R

2007-01-01

The USDOE has initiated an impact assessment of existing vadose zone contamination at the Hanford Site SX tank farm in southeastern Washington State. The assessment followed the Resource Conservation and Recovery Act (RCRA) Corrective Action process to address the impacts of past tank waste releases to the vadose zone at the single-shell tank farm. Numerical models were developed that consider the extent of contamination presently within the vadose zone and predict contaminant movement through the vadose zone to groundwater. The transport of representative mobile (technetium-99) and immobile (cesium-137) constituents was evaluated in modeling. The model considered the accelerated movement of moisture around and beneath single-shell tanks that is attributed to bare, gravel surfaces resulting from the construction of the underground storage tanks. Infiltration, possibly nearing 100 mm yr -1 , is further amplified in the tank farm because of the umbrella effect created by percolating moisture being diverted by the impermeable, sloping surface of the large, 24-m-diameter, buried tank domes. For both the base case (no-action alternative) simulation and a simulation that considered placement of an interim surface barrier to minimize infiltration, predicted, groundwater concentrations for technetium-99 at the SX tank farm boundary were exceedingly high, on the order of 10 6 pCi L -1 . The predicted concentrations are, however, somewhat conservative because of our use of two-dimensional modeling for a three-dimensional problem. A series of simulations were performed, using recharge rates of 50, 30, and 10 mm yr -1 , and compared to the basecase(100 mm yr -1 ) results. As expected, lowering meteoric recharge delayed peak arrival times and reduced peak concentrations at the tank farm boundary

Impact Assessment of Existing Vadose Zone Contamination at the Hanford Site SX Tank Farm

International Nuclear Information System (INIS)

Khaleel, Raziuddin; White, Mark D.; Oostrom, Martinus; Wood, Marcus I.; Mann, Frederick M.; Kristofzski, John G.

2007-01-01

The USDOE has initiated an impact assessment of existing vadose zone contamination at the Hanford Site SX tank farm in southeastern Washington State. The assessment followed the Resource Conservation and Recovery Act (RCRA) Corrective Action process to address the impacts of past tank waste releases to the vadose zone at the single-shell tank farm. Numerical models were developed that consider the extent of contamination presently within the vadose zone and predict contaminant movement through the vadose zone to groundwater. The transport of representative mobile (technetium-99) and immobile (cesium-137) constituents was evaluated in modeling. The model considered the accelerated movement of moisture around and beneath single-shell tanks that is attributed to bare, gravel surfaces resulting from the construction of the underground storage tanks. Infiltration, possibly nearing 100 mm yr -1 , is further amplified in the tank farm because of the umbrella effect created by percolating moisture being diverted by the impermeable, sloping surface of the large, 24-m-diameter, buried tank domes. For both the base case (no-action alternative) simulation and a simulation that considered placement of an interim surface barrier to minimize infiltration, predicted groundwater concentrations for technetium-99 at the SX tank farm boundary were exceedingly high, on the order of 106 pCi L-1. The predicted concentrations are, however, somewhat conservative because of our use of two-dimensional modeling for a three-dimensional problem. A series of simulations were performed, using recharge rates of 50, 30, and 10 mm yr -1 , and compared to the base case (100 mm yr -1 ) results. As expected, lowering meteoric recharge delayed peak arrival times and reduced peak concentrations at the tank farm boundary.

Monitoring Plan for Fiscal Year 1999 Borehole Logging at 200 East Area Specific Retention Facilities

International Nuclear Information System (INIS)

Horton, D.G.

1999-01-01

The Hanford Groundwater Monitoring Project's vadose zone monitoring effort for fiscal year (FY) 1999 involves monitoring 30 boreholes for moisture content and gamma-ray emitting radionuclides. The boreholes are associated with specific retention trenches and cribs in the 200 East Area of the Hanford Site. The facilities to be monitored are the 216-A-2, -4, and -7 cribs, the 216-A-18 trench, the 216-B-14 through -19 cribs, the 216-B-20 through -34, -53A, and -58 trenches, the 216-B-35 through -42 trenches, and the 216-C-5 crib. This monitoring plan describes the facilities and the vadose zone at the cribs and trenches to be monitored; the field activities to be accomplished; the constituents of interest and the monitoring methods, including calibration issues; and the quality assurance and quality control requirements governing the monitoring effort. The results from the FY 1999 monitoring will show the current configuration of subsurface contamination and will be compared with past monitoring results to determine whether changes in contaminant distribution have occurred since the last monitoring effort

Integrated Field, Laboratory, and Modeling Studies to Determine the Effects of Linked Microbial and Physical Spatial Heterogeneity on Engineered Vadose Zone Bioremediation

Energy Technology Data Exchange (ETDEWEB)

Fred Brokman; John Selker; Mark Rockhold

2004-01-26

While numerous techniques exist for remediation of contaminant plumes in groundwater or near the soil surface, remediation methods in the deep vadose zone are less established due to complex transport dynamics and sparse microbial populations. There is a lack of knowledge on how physical and hydrologic features of the vadose zone control microbial growth and colonization in response to nutrient delivery during bioremediation. Yet pollution in the vadose zone poses a serious threat to the groundwater resources lying deeper in the sediment. While the contaminants may be slowly degraded by native microbial communities, microbial degradation rates rarely keep pace with the spread of the pollutant. It is crucial to increase indigenous microbial degradation in the vadose zone to combat groundwater contamination.

Integrated Field, Laboratory, and Modeling Studies to Determine the Effects of Linked Microbial and Physical Spatial Heterogeneity on Engineered Vadose Zone Bioremediation

Energy Technology Data Exchange (ETDEWEB)

Brockman, Fred J.; Selker, John S.; Rockhold, Mark L.

2004-10-31

Executive Summary - While numerous techniques exist for remediation of contaminant plumes in groundwater or near the soil surface, remediation methods in the deep vadose zone are less established due to complex transport dynamics and sparse microbial populations. There is a lack of knowledge on how physical and hydrologic features of the vadose zone control microbial growth and colonization in response to nutrient delivery during bioremediation. Yet pollution in the vadose zone poses a serious threat to the groundwater resources lying deeper in the sediment. While the contaminants may be slowly degraded by native microbial communities, microbial degradation rates rarely keep pace with the spread of the pollutant. It is crucial to increase indigenous microbial degradation in the vadose zone to combat groundwater contamination...

Colloid-Facilitated Transport of Radionuclides through the Vadose Zone

International Nuclear Information System (INIS)

Flury, Markus; Harsh, James B.; Zachara, John M.; McCarthy, John F.; Lichtner, Peter C.

2006-01-01

This project seeks to improve the basic understanding of the role of colloids in facilitating the transport of contaminants in the vadose zone. We focus on three major thrusts: (1) thermodynamic stability and mobility of colloids formed by reactions of sediments with highly alkaline tank waste solutions, (2) colloid-contaminant interactions, and (3) in-situ colloid mobilization and colloid facilitated contaminant transport occurring in both contaminated and uncontaminated Hanford sediments

Application of Vadose Zone Monitoring Technology for Characterization of Leachate Generation in Landfills

Science.gov (United States)

aharoni, imri; dahan, ofer

2016-04-01

Ground water contamination due to landfill leachate percolation is considered the most severe environmental threat related to municipal solid waste landfills. Natural waste degradation processes in landfills normally produce contaminated leachates up to decades after the waste has been buried. Studies have shown that understanding the mechanisms which govern attenuation processes and the fate of pollutants in the waste and in the underlying unsaturated zone is crucial for evaluation of environmental risks and selection of a restoration strategy. This work focuses on a closed landfill in the coastal plain of Israel that was active until 2002 without any lining infrastructure. A vadose zone monitoring system (VMS) that was implemented at the site enables continuous measurements across the waste body (15 m thick) and underlying sandy vadose zone (16 m thick). Data collected by the VMS included continuous measurements of water content as well as chemical composition of the leachates across the entire waste and vadose zone cross section. Results indicated that winter rain percolated through the waste, generating wetting waves which were observed across the waste and unsaturated sediment from land surface until groundwater at 31 m bls. Quick percolation and high fluxes were observed in spite of the clay cover that was implemented at the site as part of the rehabilitation scheme. The results show that the flow pattern is controlled by a preferential mechanism within the waste body. Specific sections showed rapid fluxes in response to rain events, while other sections remained unaffected. In the underlying sandy vadose zone the flow pattern exhibited characteristics of matrix flow. Yet, some sections received higher fluxes due to the uneven discharge of leachates from the overlying waste body. Water samples collected from the waste layer indicate production of highly polluted leachates over 14 years after the landfill was closed. The chemical composition within the waste

Transport and degradation of perchlorate in deep vadose zone: implications from direct observations during bioremediation treatment

Directory of Open Access Journals (Sweden)

O. Dahan

2017-08-01

Full Text Available An in situ bioremediation experiment of a deep vadose zone ( ∼  40 m contaminated with a high concentration of perchlorate (> 25 000 mg L−1 was conducted through a full-scale field operation. Favourable environmental conditions for microbiological reduction of perchlorate were sought by infiltrating an electron donor-enriched water solution using drip irrigation underlying an airtight sealing liner. A vadose zone monitoring system (VMS was used for real-time tracking of the percolation process, the penetration depth of dissolved organic carbon (DOC, and the variation in perchlorate concentration across the entire soil depth. The experimental conditions for each infiltration event were adjusted according to insight gained from data obtained by the VMS in previous stages. Continuous monitoring of the vadose zone indicated that in the top 13 m of the cross section, perchlorate concentration is dramatically reduced from thousands of milligrams per litre to near-detection limits with a concurrent increase in chloride concentration. Nevertheless, in the deeper parts of the vadose zone (< 17 m, perchlorate concentration increased, suggesting its mobilization down through the cross section. Breakthrough of DOC and bromide at different depths across the unsaturated zone showed limited migration capacity of biologically consumable carbon and energy sources due to their enhanced biodegradation in the upper soil layers. Nevertheless, the increased DOC concentration with concurrent reduction in perchlorate and increase in the chloride-to-perchlorate ratio in the top 13 m indicate partial degradation of perchlorate in this zone. There was no evidence of improved degradation conditions in the deeper parts where the initial concentrations of perchlorate were significantly higher.

Characterization of the vadose zone above a shallow aquifer contaminated with gas condensate hydrocarbons

International Nuclear Information System (INIS)

Sublette, K.; Duncan, K.; Thoma, G.; Todd, T.

2002-01-01

A gas production site in the Denver Basin near Ft. Lupton, Colorado has leaked gas condensate hydrocarbons from an underground concrete tank used to store produced water. The leak has contaminated a shallow aquifer. Although the source of pollution has been removed, a plume of hydrocarbon contamination still remains for nearly 46 m from the original source. An extensive monitoring program was conducted in 1993 of the groundwater and saturated sediments. The objective was to determine if intrinsic aerobic or anaerobic bioremediation of hydrocarbons occurred at the site at a rate that would support remediation. Geochemical indicators of hydrogen biodegradation by microorganisms in the saturated zone included oxygen depletion, increased alkalinity, sulfate depletion, methane production and Fe2+ production associated with hydrogen contamination. The presence of sulfate-reducing bacteria and methanogens was also much higher in the contaminated sediments. Degraded hydrocarbon metabolites were found in contaminated groundwater. An extensive characterization of the vadose zone was conducted in which the vadose zone was sample in increments of 15 cm from the surface to the water table at contaminated and non contaminated sites. The samples were tested for individual C3+ hydrocarbons, methane, CO2, total organic carbon, total inorganic carbon, and total petroleum hydrocarbons. The vadose zone consisted of an active and aerobic bioreactor fueled by condensate hydrocarbons transported into the unsaturated zone by evaporation of hydrocarbons at the water table. It was concluded that the unsaturated zone makes an important contribution to the natural attenuation of gas condensate hydrocarbons in the area. 17 refs., 2 tabs., 28 figs

In situ vadose zone remediation of petroleum-contaminated soils

International Nuclear Information System (INIS)

Greacen, J.R.; Finkel, D.J.

1991-01-01

This paper discusses a pilot-scale system treating vadose zone soils contaminated with petroleum products constructed and operated at a former petroleum bulk storage terminal in New England. A site investigation following decommissioning activities identified more than 100,000 yds of soil at the site contaminated by both No. 2 fuel oil and gasoline. Soil cleanup criteria of 50 ppm TPH and 0.25 ppm BTEX were established. A pilot-scale treatment unit with dimensions of 125 ft x 125 ft x 6 ft was constructed to evaluate the potential for in situ treatment of vadose zone soils. Contaminant levels in pilot cell soils ranged from 0 to 5,250 ppm TPH and 0.0 to 4.2 ppm BTEX. Two soil treatment methods n the pilot system were implemented; venting to treat the lighter petroleum fractions and bioremediation to treat the nonvolatile petroleum constituents. Seven soil gas probes were installed to monitor pressure and soil gas vapor concentrations in the subsurface. Changes in soil gas oxygen and carbon dioxide concentrations were used as an indirect measure of enhanced bioremediation of pilot cell soils. After operating the system for a period of 2.5 months, soil BTEX concentrations were reduced to concentrations below the remediation criteria for the site

Modeling foam delivery mechanisms in deep vadose-zone remediation using method of characteristics

Energy Technology Data Exchange (ETDEWEB)

Roostapour, A. [Craft and Hawkins Department of Petroleum Engineering, Louisiana State University, Baton Rouge, LA 70803 (United States); Kam, S.I., E-mail: kam@lsu.edu [Craft and Hawkins Department of Petroleum Engineering, Louisiana State University, Baton Rouge, LA 70803 (United States)

2012-12-15

Highlights: Black-Right-Pointing-Pointer A new mathematical framework established for vadose-zone foam remediation. Black-Right-Pointing-Pointer Graphical solutions presented by Method of Characteristics quantitatively. Black-Right-Pointing-Pointer Effects of design parameters in the field applications thoroughly investigated. Black-Right-Pointing-Pointer Implication of modeling study for successful field treatment discussed. - Abstract: This study investigates foam delivery mechanisms in vadose-zone remediation by using Method of Characteristics (MoC), a mathematical tool long been used for the analysis of miscible and immiscible flooding in porous media in petroleum industry. MoC converts the governing material-balance partial differential equations into a series of ordinary differential equations, and the resulting solutions are in a form of wave propagation (more specifically, for chemical species and phase saturations) through the system as a function of time and space. Deep vadose-zone remediation has special features compared to other conventional remediation applications. They include, not limited to, a high level of heterogeneity, a very dry initial condition with low water saturation (S{sub w}), pollutants such as metals and radionuclides fully dissolved in groundwater, and a serious concern about downward migration during the remediation treatments. For the vadose-zone remediation processes to be successful, the injected aqueous phase should carry chemicals to react with pollutants and precipitate them for immobilization and stabilization purposes. As a result, foams are believed to be an effective means, and understanding foam flow mechanism in situ is a key to the optimal design of field applications. Results show that foam delivery mechanism is indeed very complicated, making the optimum injection condition field-specific. The five major parameters selected (i.e., initial saturation of the medium, injection foam quality, surfactant adsorption, foam

Modeling foam delivery mechanisms in deep vadose-zone remediation using method of characteristics

International Nuclear Information System (INIS)

Roostapour, A.; Kam, S.I.

2012-01-01

Highlights: ► A new mathematical framework established for vadose-zone foam remediation. ► Graphical solutions presented by Method of Characteristics quantitatively. ► Effects of design parameters in the field applications thoroughly investigated. ► Implication of modeling study for successful field treatment discussed. - Abstract: This study investigates foam delivery mechanisms in vadose-zone remediation by using Method of Characteristics (MoC), a mathematical tool long been used for the analysis of miscible and immiscible flooding in porous media in petroleum industry. MoC converts the governing material-balance partial differential equations into a series of ordinary differential equations, and the resulting solutions are in a form of wave propagation (more specifically, for chemical species and phase saturations) through the system as a function of time and space. Deep vadose-zone remediation has special features compared to other conventional remediation applications. They include, not limited to, a high level of heterogeneity, a very dry initial condition with low water saturation (S w ), pollutants such as metals and radionuclides fully dissolved in groundwater, and a serious concern about downward migration during the remediation treatments. For the vadose-zone remediation processes to be successful, the injected aqueous phase should carry chemicals to react with pollutants and precipitate them for immobilization and stabilization purposes. As a result, foams are believed to be an effective means, and understanding foam flow mechanism in situ is a key to the optimal design of field applications. Results show that foam delivery mechanism is indeed very complicated, making the optimum injection condition field-specific. The five major parameters selected (i.e., initial saturation of the medium, injection foam quality, surfactant adsorption, foam strength, and foam stability) are shown to be all important, interacting with each other. Results also

Vadose Zone Infiltration Rate at Hanford, Washington, Inferred from Sr Isotope Measurements

International Nuclear Information System (INIS)

Maher, Katharine; DePaolo, Donald J.; Conrad, Mark E.; Serne, R. Jeffrey

2003-01-01

Sr isotope ratios were measured in the pore water, acid extracts, and sediments of a 70-m vadose zone core to obtain estimates of the long-term infiltration flux for a site in the Hanford/DOE complex in eastern Washington State. The 87Sr/86Sr values of the pore waters decrease systematically with depth, from a high value of 0.721 near the surface toward the bulk sediment average value of 0.711. Estimates of the bulk weathering rate combined with Sr isotopic data were used to constrain the long-term (century to millenial scale) natural diffuse infiltration flux for the site given both steady state and nonsteady state conditions. The models suggest that the infiltration fluc for the site is 7+- 3 mm/yr. The method shows potential for providing long-term in situ estimates of infiltration rates for deep heterogeneous vadose zones

Challenges for Deep Vadose Zone Remediation at the Hanford Site

International Nuclear Information System (INIS)

Morse, John G.; Charboneau, Briant L.; Lober, Robert W.; Triplett, Mark B.

2008-01-01

The 'deep vadose zone' is defined as the region below the practical depth of surface remedy influence (e.g., excavation or barrier). At the Hanford Site, this region of the Central Plateau poses unique challenges for characterization and remediation. The contaminants in this region also pose a potentially significant continuing or future threat to groundwater. Currently, deep vadose zone characterization efforts and remedy selection are spread over multiple waste site Operable Units and tank farm Waste Management Areas. A particular challenge for this effort is the situation in which past leaks from single-shell tanks have become commingled with discharges from nearby liquid disposal sites. The Hanford Site is working with all affected parties, including the Washington State Department of Ecology, the Environmental Protection Agency, DOE-RL, DOE-ORP, and multiple contractor organizations to develop a unified approach to conducting work and reaching remediation decisions. This effort addresses the complex and challenging technical and regulatory issues within this environment. A true inter-Agency effort is evaluating the best strategy or combination of strategies for focusing technical investigations, including treatability studies, and for attaining remedy decisions on the Hanford Site

Uemachi flexure zone investigated by borehole database and numeical simulation

Science.gov (United States)

Inoue, N.; Kitada, N.; Takemura, K.

2014-12-01

The Uemachi fault zone extending north and south, locates in the center of the Osaka City, in Japan. The Uemachi fault is a blind reverse fault and forms the flexure zone. The effects of the Uemachi flexure zone are considered in constructing of lifelines and buildings. In this region, the geomorphological survey is difficult because of the regression of transgression. Many organizations have carried out investigations of fault structures. Various surveys have been conducted, such as seismic reflection survey in and around Osaka. Many borehole data for construction conformations have been collected and the geotechnical borehole database has been constructed. The investigation with several geological borehole data provides the subsurface geological information to the geotechnical borehole database. Various numerical simulations have been carried out to investigate the growth of a blind reverse fault in unconsolidated sediments. The displacement of the basement was given in two ways. One is based on the fault movement, such as dislocation model, the other is a movement of basement block of hanging wall. The Drucker-Prager and elastic model were used for the sediment and basement, respectively. The simulation with low and high angle fault movements, show the good agree with the actual distribution of the marine clay inferred from borehole data in the northern and southern Uemachi fault flexure zone, respectively. This research is partly funded by the Comprehensive Research on the Uemachi Fault Zone (from FY2010 to FY2012) by The Ministry of Education, Culture, Sports, Science and Technology (MEXT).

Modeling potential migration of petroleum hydrocarbons from a mixed-waste disposal site in the vadose zone

International Nuclear Information System (INIS)

Rawson, S.A.; Walton, J.C.; Baca, R.G.

1989-01-01

Environmental monitoring of a mixed-waste disposal site at the Idaho National Engineering Laboratory has confirmed release and migration into the vadose zone of: (1) chlorinated hydrocarbons in the vapor phase and (2) trace levels of certain transuranic elements. The finding has prompted an evaluation of the potential role of waste petroleum hydrocarbons in mediating or influencing contaminant migration from the disposal site. Disposal records indicate that a large volume of machine oil contaminated with transuranic isotopes was disposed at the site along with the chlorinated solvents and other radioactive wastes. A multiphase flow model was used to assess the possible extent of oil and vapor movement through the 177 m thick vadose zone. One dimensional simulations were performed to estimate the vertical distribution of the vapor phase, the aqueous phase, and immiscible free liquid as a function of time. The simulations indicate that the oil may migrate slowly through the vadose zone, to potentially significant depths. Calculated transport rates support the following ranking with regard to relative mobility: vapor phase > aqueous phase > free liquid. 21 refs., 7 figs., 2 tabs

Results of 1998 spectral gamma-ray monitoring of boreholes at the 216-Z-1A tile field, 216-Z-9 trench, and 216-Z-12 crib

International Nuclear Information System (INIS)

Horton, D.G.; Randall, R.R.

1998-09-01

This document describes the results of fiscal year 1998 vadose zone monitoring of three inactive liquid waste disposal facilities associated with the Plutonium Finishing Plant: the 216-Z-1A tile field, the 216-Z-9 trench, and the 216-Z-12 crib. Monitoring consisted of spectral gamma-ray logging of 21 boreholes. This work was performed by Pacific Northwest National Laboratory in conjunction with Three Rivers Scientific and Waste management Federal Services, inc. Northwest Operations. These three liquid waste disposal facilities were chosen for monitoring because they were identified as containing some of the most significant sources of radioactive contamination in the Hanford Site vadose zone. The basic question addressed by this logging activity is ''Has the configuration of subsurface contamination changed since it was last measured?'' Previous borehole logging and laboratory analyses provide the baseline data to help answer this question

Characterization of Vadose Zone Sediments from C Waste Management Area: Investigation of the C-152 Transfer Line Leak

Energy Technology Data Exchange (ETDEWEB)

Brown, Christopher F.; Serne, R. Jeffrey; Bjornstad, Bruce N.; Valenta, Michelle M.; Lanigan, David C.; Vickerman, Tanya S.; Clayton, Ray E.; Geiszler, Keith N.; Iovin, Cristian; Clayton, Eric T.; Kutnyakov, Igor V.; Baum, Steven R.; Lindberg, Michael J.; Orr, Robert D.

2008-09-11

The sodium data was removed due to potential contamination introduced during the acid extraction process. The rest of the text remains unchanged from the original report issued in January 2007. The overall goal of the Tank Farm Vadose Zone Project, led by CH2M HILL Hanford Group, Inc., is to define risks from past and future single-shell tank farm activities at Hanford. To meet this goal, CH2M HILL Hanford Group, Inc., tasked scientists from Pacific Northwest National Laboratory to perform detailed analyses on vadose zone sediments from within waste management area (WMA) C. Specifically, this report contains all the geologic, geochemical, and selected physiochemical characterization data compiled on vadose zone sediment recovered from direct-push samples collected around the site of an unplanned release (UPR), UPR-200-E-82, adjacent to the 241-C-152 Diversion Box located in WMA C.

Vadose zone monitoring at the Radioactive Waste Management Complex at the Idaho National Engineering Laboratory, 1985--1989

International Nuclear Information System (INIS)

McElroy, D.L.

1990-12-01

Vadose zone monitoring at the Radioactive Waste Management Complex (RWMC) of the Idaho National Engineering Laboratory (INEL) was implemented under the Subsurface Investigation Program Plan. The objective of the Subsurface Investigation Program was to characterize the subsurface at the RWMC in order to measure and predict radionuclide transport. Soil moisture sensors were installed to characterize the uniformity of water entry to the surficial sediments and moisture flux in the surficial sediments and the deeper stratigraphic units. From 1985 to 1987, a network of vadose zone instruments was installed in sediments at the RWMC. The instruments included psychrometers, gypsum blocks, heat-dissipation sensors (HDSs), tensiometers, lysimeters, and neutron access tubes. These instruments were placed at depths up to 230 ft below land surface (BLS) in a heterogeneous geologic system comprised of sediments that overlie and are intercalated with basalt flows. After organic contaminants were detected in the subsurface at the RWMC in 1988, the vadose zone monitoring project was incorporated into a broader characterization effort. This report presents the analyses of the vadose zone monitoring data collected from FY-1985 to FY-1989. The performance of the instruments are compared. Matric potential ranges and trends in the surficial sediments and interbeds are discussed. Hydraulic gradients are calculated to determine the direction of moisture movement. Using the neutron logging data in conjunction with the matric potential and hydraulic gradient data, infiltration is examined with respect to seasonal nature and source. 14 refs., 19 figs., 4 tabs

Climate, soil, and vegetation controls on the temporal variability of vadose zone transport

NARCIS (Netherlands)

Harman, C.J.; Rao, P.S.C.; Basu, N.B.; McGrath, G.S.; Kumar, P.; Sivapalan, M.

2011-01-01

Temporal patterns of solute transport and transformation through the vadose zone are driven by the stochastic variability of water fluxes. This is determined by the hydrologic filtering of precipitation variability into infiltration, storage, drainage, and evapotranspiration. In this work we develop

Geophysical borehole logging in the unsaturated zone, Yucca Mountain, Nevada

International Nuclear Information System (INIS)

Schimschal, U.; Nelson, P.H.

1991-01-01

Borehole geophysical logging for site characterization in the volcanic rocks at the proposed nuclear waste repository at Yucca Mountain, Nevada, requires data collection under rather unusual conditions. Logging tools must operate in rugose, dry holes above the water table in the unsaturated zone. Not all logging tools will operate in this environment, therefore; careful consideration must be given to selection and calibration. A sample suite of logs is presented that demonstrates correlation of geological formations from borehole to borehole, the definition of zones of altered mineralogy, and the quantitative estimates of rock properties. The authors show the results of an exploratory calculation of porosity and water saturation based upon density and epithermal neutron logs. Comparison of the results with a few core samples is encouraging, particularly because the logs can provide continuous data in boreholes where core samples are not available

Aquifer recharge with stormwater runoff in urban areas: Influence of vadose zone thickness on nutrient and bacterial transfers from the surface of infiltration basins to groundwater.

Science.gov (United States)

Voisin, Jérémy; Cournoyer, Benoit; Vienney, Antonin; Mermillod-Blondin, Florian

2018-05-16

Stormwater infiltration systems (SIS) have been built in urban areas to reduce the environmental impacts of stormwater runoff. Infiltration basins allow the transfer of stormwater runoff to aquifers but their abilities to retain contaminants depend on vadose zone properties. This study assessed the influence of vadose zone thickness (VZT) on the transfer of inorganic nutrients (PO 4 3- , NO 3 - , NH 4 + ), dissolved organic carbon (total -DOC- and biodegradable -BDOC-) and bacteria. A field experiment was conducted on three SIS with a thin vadose zone (zone (>10 m). Water samples were collected at three times during a rainy period of 10 days in each infiltration basin (stormwater runoff), in the aquifer impacted by infiltration (impacted groundwater) and in the same aquifer but upstream of the infiltration area (non-impacted groundwater). Inorganic nutrients, organic matter, and dissolved oxygen (DO) were measured on all water samples. Bacterial community structures were investigated on water samples through a next-generation sequencing (NGS) scheme of 16S rRNA gene amplicons (V5-V6). The concentrations of DO and phosphate measured in SIS-impacted groundwaters were significantly influenced by VZT due to distinct biogeochemical processes occurring in the vadose zone. DOC and BDOC were efficiently retained in the vadose zone, regardless of its thickness. Bacterial transfers to the aquifer were overall low, but data obtained on day 10 indicated a significant bacterial transfer in SIS with a thin vadose zone. Water transit time and water saturation of the vadose zone were found important parameters for bacterial transfers. Most bacterial taxa (>60%) from impacted groundwaters were not detected in stormwater runoff and in non-impacted groundwaters, indicating that groundwater bacterial communities were significantly modified by processes associated with infiltration (remobilization of bacteria from vadose zone and/or species sorting). Copyright © 2018 Elsevier B

200-ZP-1 operable unit borehole summary report for FY 1995 and FY 1996

International Nuclear Information System (INIS)

Darrach, M.E.

1996-10-01

This document details the well construction, sampling, analyses, and geologic character of the Ringold Formation fluvial unit E gravels as encountered in 16 boreholes in the 200-ZP-1 Operable Unit. These boreholes were drilled by Water Development Hanford Corporation during fiscal years 1995 and 1996. Two of the sixteen boreholes were abandoned; the remaining 14 boreholes were completed as functioning production and compliance wells. The borehole logs and well summary sheets included as Appendices A and B of this document, respectively, depict and describe the vadose zone stratigraphic units encountered during the course of drilling. Appendix C contains the results of sieve analyses conducted on samples obtained via resonant sonic coring and standard split-spoon methods. The sieve analyses were the driver behind the majority of the well designs. Also, for completeness, Appendices D and E contain the well design calculations and the well development process

Conceptual Model of Uranium in the Vadose Zone for Acidic and Alkaline Wastes Discharged at the Hanford Site Central Plateau

Energy Technology Data Exchange (ETDEWEB)

Truex, Michael J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Szecsody, James E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Qafoku, Nikolla [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Serne, R. Jeffrey [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2014-09-01

Historically, uranium was disposed in waste solutions of varying waste chemistry at the Hanford Site Central Plateau. The character of how uranium was distributed in the vadose zone during disposal, how it has continued to migrate through the vadose zone, and the magnitude of potential impacts on groundwater are strongly influenced by geochemical reactions in the vadose zone. These geochemical reactions can be significantly influenced by the disposed-waste chemistry near the disposal location. This report provides conceptual models and supporting information to describe uranium fate and transport in the vadose zone for both acidic and alkaline wastes discharged at a substantial number of waste sites in the Hanford Site Central Plateau. The conceptual models include consideration of how co-disposed acidic or alkaline fluids influence uranium mobility in terms of induced dissolution/precipitation reactions and changes in uranium sorption with a focus on the conditions near the disposal site. This information, when combined with the extensive information describing uranium fate and transport at near background pH conditions, enables focused characterization to support effective fate and transport estimates for uranium in the subsurface.

Evidence of linked biogeochemical and hydrological processes in homogeneous and layered vadose zone systems

Science.gov (United States)

McGuire, J. T.; Hansen, D. J.; Mohanty, B. P.

2010-12-01

Understanding chemical fate and transport in the vadose zone is critical to protect groundwater resources and preserve ecosystem health. However, prediction can be challenging due to the dynamic hydrologic and biogeochemical nature of the vadose zone. Additional controls on hydrobiogeochemical processes are added by subsurface structural heterogeneity. This study uses repacked soil column experiments to quantify linkages between microbial activity, geochemical cycling and hydrologic flow. Three “short” laboratory soil columns were constructed to evaluate the effects of soil layering: a homogenized medium-grained sand, homogenized organic-rich loam, and a sand-over-loam layered column. In addition, two “long” columns were constructed using either gamma-irradiated (sterilized) or untreated sediments to evaluate the effects of both soil layers and the presence of microorganisms. The long columns were packed identically; a medium-grained sand matrix with two vertically separated and horizontally offset lenses of organic-rich loam. In all 5 columns, downward and upward infiltration of water was evaluated to simulate rainfall and rising water table events respectively. In-situ colocated probes were used to measure soil water content, matric potential, Eh, major anions, ammonium, Fe2+, and total sulfide. Enhanced biogeochemical cycling was observed in the short layered column versus the short, homogeneous columns, and enumerations of iron and sulfate reducing bacteria were 1-2 orders of magnitude greater. In the long columns, microbial activity caused mineral bands and produced insoluble gases that impeded water flow through the pores of the sediment. Capillary barriers, formed around the lenses due to soil textural differences, retarded water flow rates through the lenses. This allowed reducing conditions to develop, evidenced by the production of Fe2+ and S2-. At the fringes of the lenses, Fe2+ oxidized to form Fe(III)-oxide bands that further retarded water

Baseline mapping study of the Steed Pond aquifer and vadose zone beneath A/M Area, Savannah River Site, Aiken, South Carolina

International Nuclear Information System (INIS)

Jackson, D.G. Jr.

2000-01-01

This report presents the second phase of a baseline mapping project conducted for the Environmental Restoration Department (ERD) at Savannah River Site. The purpose of this second phase is to map the structure and distribution of mud (clay and silt-sized sediment) within the vadose zone beneath A/M Area. The results presented in this report will assist future characterization and remediation activities in the vadose zone and upper aquifer zones in A/M Area

Linking carbon and hydrologic fluxes in the critical zone: Observations from high-frequency monitoring of a weathered bedrock vadose zone

Science.gov (United States)

Tune, A. K.; Druhan, J. L.; Wang, J.; Cargill, S.; Murphy, C.; Rempe, D. M.

2017-12-01

A principle challenge in quantifying feedbacks between continental weathering and atmospheric CO2 is to improve understanding of how biogeochemical processes in the critical zone influence the distribution and mobility of organic and inorganic carbon. In particular, in landscapes characterized by thin soils and heterogeneous weathered and fractured bedrock, little data exist to inform and constrain predictive models for carbon dynamics. Here, we present the results of an intensive water and gas sampling campaign across an 18 m thick, variably saturated argillite weathering profile in the Eel River CZO. We monitor water content in situ and regularly collect samples of freely-draining water, tightly-held water, and gas through wet and dry seasons using a novel Vadose-zone Monitoring System (VMS) consisting of sensors and samplers distributed across a 20 m long inclined borehole. This novel approach facilitates the interception of gas and water during transport across the entire variably saturated weathering profile. The data demonstrate that seasonal changes in saturation control the vertical distribution and mobility of carbon in the fractured critical zone. Concentrations of gaseous CO2, O2, and dissolved organic and inorganic carbon fluctuate significantly and repeatably with seasonal additions of water infiltrating the weathered bedrock. A persistent vertical structure in the concentrations of dissolved phases and gas concentrations broadly corresponds to depths associated with unsaturated, seasonally saturated, and chronically saturated zones. Associated variations in the vertical structure of mineralogy and elemental composition, including solid phase organic carbon content, are observed in core obtained during drilling. Together, our observations indicate significant respiration of organic carbon at depths greater than the base of the soil, and thus motivate further investigation of the role of heterogeneous weathered, bedrock environments, which are needed to

Site Characterization Data from the U3ax/bl Exploratory Boreholes at the Nevada Test Site

International Nuclear Information System (INIS)

2005-01-01

potential gradient (water moves upward, via evapotranspiration) for the entire vertical depth. Very little liquid flow occurs through the vadose zone. The direction of flow in the upper vadose zone (approximately the upper 35 meters) is upward, based on unsaturated hydraulic conductivity data, water potential data, and environmental tracer data

Site Characterization Data from the U3ax/bl Exploratory Boreholes at the Nevada Test Site

Energy Technology Data Exchange (ETDEWEB)

Bechtel Nevada; U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office

2005-08-01

potential gradient (water moves upward, via evapotranspiration) for the entire vertical depth. Very little liquid flow occurs through the vadose zone. The direction of flow in the upper vadose zone (approximately the upper 35 meters) is upward, based on unsaturated hydraulic conductivity data, water potential data, and environmental tracer data.

Petrophysical characteristics of basalt in the vadose zone, Idaho National Engineering Laboratory, Eastern Snake River Plain, Idaho

International Nuclear Information System (INIS)

Knutson, C.F.; Harrison, W.E.; Smith, R.P.

1989-01-01

We have used a core characterization system to measure bulk densities, porosities, and permeabilities of basalt lavas from the vadose zone at the Idaho National Engineering Laboratory (INEL). At the INEL, basalt lava flows with intercalated alluvial, aeolian, and lacustrine sediments extend to depths of one kilometer or more. Individual lava flows are generally less than 15 meters thick and commonly have vesicular tops and bottoms with massive basalt in their interiors. Petrophysical characterization is essential to an understanding of fluid movement in the vadose zone and in the saturated zone. Many hundreds of closely spaced permeability/porosity/bulk density measurements have defined the variability of these parameters within and between individual basalt flows. Based on geological logging and porosity/permeability measurements made on many hundred feet of core, we feel that a rather sophisticated and rigorous logging program is necessary to characterize these complex and highly variable basaltic flow units. This paper endeavors to provide a petrophysical/geological conceptual model of the Snake River Plain basalts from the vadose zone under the Radioactive Waste Management Complex area at the INEL. We hope that this model will aid in subsequent geotechnical logging in this portion of the Eastern Snake River Plain. 8 refs., 14 figs., 2 tabs

Sampling and Hydrogeology of the Vadose Zone Beneath the 300 Area Process Ponds

International Nuclear Information System (INIS)

Bjornstad, Bruce N.

2004-01-01

Four open pits were dug with a backhoe into the vadose zone beneath the former 300 Area Process Ponds in April 2003. Samples were collected about every 2 feet for physical, chemical, and/or microbiological characterization. This reports presents a stratigraphic and geohydrologic summary of the four excavations

Using the natural biodegradation potential of shallow soils for in-situ remediation of deep vadose zone and groundwater

Energy Technology Data Exchange (ETDEWEB)

Avishai, Lior; Siebner, Hagar; Dahan, Ofer, E-mail: odahan@bgu.ac.il; Ronen, Zeev, E-mail: zeevrone@bgu.ac.il

2017-02-15

Highlights: • Integrated in-situ remediation treatment for soil, vadose zone and groundwater. • Turning the topsoil into an efficient bioreactor for perchlorate degradation. • Treating perchlorate leachate from the deep vadose zone in the topsoil. • Zero effluents discharge from the remediation process. - Abstract: In this study, we examined the ability of top soil to degrade perchlorate from infiltrating polluted groundwater under unsaturated conditions. Column experiments designed to simulate typical remediation operation of daily wetting and draining cycles of contaminated water amended with an electron donor. Covering the infiltration area with bentonite ensured anaerobic conditions. The soil remained unsaturated, and redox potential dropped to less than −200 mV. Perchlorate was reduced continuously from ∼1150 mg/L at the inlet to ∼300 mg/L at the outlet in daily cycles. Removal efficiency was between 60 and 84%. No signs of bioclogging were observed during three operation months although occasional iron reduction observed due to excess electron donor. Changes in perchlorate reducing bacteria numbers were inferred from an increased in pcrA gene abundances from ∼10{sup 5} to 10{sup 7} copied per gram at the end of the experiment indicating the growth of perchlorate-reducing bacteria. We proposed that the topsoil may serve as a bioreactor to treat high concentrations of perchlorate from the contaminated groundwater. The treated water that infiltrates from the topsoil through the vadose zone could be used to flush perchlorate from the deep vadose zone into the groundwater where it is retrieved again for treatment in the topsoil.

Using the natural biodegradation potential of shallow soils for in-situ remediation of deep vadose zone and groundwater

International Nuclear Information System (INIS)

Avishai, Lior; Siebner, Hagar; Dahan, Ofer; Ronen, Zeev

2017-01-01

Highlights: • Integrated in-situ remediation treatment for soil, vadose zone and groundwater. • Turning the topsoil into an efficient bioreactor for perchlorate degradation. • Treating perchlorate leachate from the deep vadose zone in the topsoil. • Zero effluents discharge from the remediation process. - Abstract: In this study, we examined the ability of top soil to degrade perchlorate from infiltrating polluted groundwater under unsaturated conditions. Column experiments designed to simulate typical remediation operation of daily wetting and draining cycles of contaminated water amended with an electron donor. Covering the infiltration area with bentonite ensured anaerobic conditions. The soil remained unsaturated, and redox potential dropped to less than −200 mV. Perchlorate was reduced continuously from ∼1150 mg/L at the inlet to ∼300 mg/L at the outlet in daily cycles. Removal efficiency was between 60 and 84%. No signs of bioclogging were observed during three operation months although occasional iron reduction observed due to excess electron donor. Changes in perchlorate reducing bacteria numbers were inferred from an increased in pcrA gene abundances from ∼10"5 to 10"7 copied per gram at the end of the experiment indicating the growth of perchlorate-reducing bacteria. We proposed that the topsoil may serve as a bioreactor to treat high concentrations of perchlorate from the contaminated groundwater. The treated water that infiltrates from the topsoil through the vadose zone could be used to flush perchlorate from the deep vadose zone into the groundwater where it is retrieved again for treatment in the topsoil.

Bayesian Markov-Chain-Monte-Carlo inversion of time-lapse crosshole GPR data to characterize the vadose zone at the Arrenaes Site, Denmark

DEFF Research Database (Denmark)

Scholer, Marie; Irving, James; Zibar, Majken Caroline Looms

2012-01-01

We examined to what extent time-lapse crosshole ground-penetrating radar traveltimes, measured during a forced infiltration experiment at the Arreneas field site in Denmark, could help to quantify vadose zone hydraulic properties and their corresponding uncertainties using a Bayesian Markov...... distributions compared with the corresponding priors, which in turn significantly improves knowledge of soil hydraulic properties. Overall, the results obtained clearly demonstrate the value of the information contained in time-lapse GPR data for characterizing vadose zone dynamics.......-chain-Monte-Carlo inversion approach with different priors. The ground-penetrating radar (GPR) geophysical method has the potential to provide valuable information on the hydraulic properties of the vadose zone because of its strong sensitivity to soil water content. In particular, recent evidence has suggested...

Effects of Lime and Concrete Waste on Vadose Zone Carbon Cycling

DEFF Research Database (Denmark)

Thaysen, Eike Marie; Jessen, Søren; Postma, D.

2014-01-01

In this work we investigate how lime and crushed concrete waste (CCW) affect carbon cycling in the vadose zone and explore whether these amendments could be employed to mitigate climate change by increasing the transport of CO2 from the atmosphere to the groundwater. We use a combination of exper......In this work we investigate how lime and crushed concrete waste (CCW) affect carbon cycling in the vadose zone and explore whether these amendments could be employed to mitigate climate change by increasing the transport of CO2 from the atmosphere to the groundwater. We use a combination...... of experimental and modeling tools to determine ongoing biogeochemical processes. Our results demonstrate that lime and CCW amendments to acid soil contribute to the climate forcing by largely increasing the soil CO2 efflux to the atmosphere. In a series of mesocosm experiments, with barley (Hordeum vulgare L.......) grown on podzolic soil material, we have investigated inorganic carbon cycling through the gaseous and liquid phases and how it is affected by different soil amendments. The mesocosm amendments comprised the addition of 0, 9.6, or 21.2 kg m−2 of crushed concrete waste (CCW) or 1 kg lime m−2. The CCW...

Imaging groundwater infiltration dynamics in the karst vadose zone with long-term ERT monitoring

Science.gov (United States)

Watlet, Arnaud; Kaufmann, Olivier; Triantafyllou, Antoine; Poulain, Amaël; Chambers, Jonathan E.; Meldrum, Philip I.; Wilkinson, Paul B.; Hallet, Vincent; Quinif, Yves; Van Ruymbeke, Michel; Van Camp, Michel

2018-03-01

Water infiltration and recharge processes in karst systems are complex and difficult to measure with conventional hydrological methods. In particular, temporarily saturated groundwater reservoirs hosted in the vadose zone can play a buffering role in water infiltration. This results from the pronounced porosity and permeability contrasts created by local karstification processes of carbonate rocks. Analyses of time-lapse 2-D geoelectrical imaging over a period of 3 years at the Rochefort Cave Laboratory (RCL) site in south Belgium highlight variable hydrodynamics in a karst vadose zone. This represents the first long-term and permanently installed electrical resistivity tomography (ERT) monitoring in a karst landscape. The collected data were compared to conventional hydrological measurements (drip discharge monitoring, soil moisture and water conductivity data sets) and a detailed structural analysis of the local geological structures providing a thorough understanding of the groundwater infiltration. Seasonal changes affect all the imaged areas leading to increases in resistivity in spring and summer attributed to enhanced evapotranspiration, whereas winter is characterised by a general decrease in resistivity associated with a groundwater recharge of the vadose zone. Three types of hydrological dynamics, corresponding to areas with distinct lithological and structural features, could be identified via changes in resistivity: (D1) upper conductive layers, associated with clay-rich soil and epikarst, showing the highest variability related to weather conditions; (D2) deeper and more resistive limestone areas, characterised by variable degrees of porosity and clay contents, hence showing more diffuse seasonal variations; and (D3) a conductive fractured zone associated with damped seasonal dynamics, while showing a great variability similar to that of the upper layers in response to rainfall events. This study provides detailed images of the sources of drip

Monitoring the Vadose Zone Moisture Regime Below a Surface Barrier

Science.gov (United States)

Zhang, Z. F.; Strickland, C. E.; Field, J. G.

2009-12-01

A 6000 m2 interim surface barrier has been constructed over a portion of the T Tank Farm in the Depart of Energy’s Hanford site. The purpose of using a surface barrier was to reduce or eliminate the infiltration of meteoric precipitation into the contaminated soil zone due to past leaks from Tank T-106 and hence to reduce the rate of movement of the plume. As part of the demonstration effort, vadose zone moisture is being monitored to assess the effectiveness of the barrier on the reduction of soil moisture flow. A vadose zone monitoring system was installed to measure soil water conditions at four horizontal locations (i.e., instrument Nests A, B, C, and D) outside, near the edge of, and beneath the barrier. Each instrument nest consists of a capacitance probe with multiple sensors, multiple heat-dissipation units, and a neutron probe access tube used to measure soil-water content and soil-water pressure. Nest A serves as a control by providing subsurface conditions outside the influence of the surface barrier. Nest B provides subsurface measurements to assess barrier edge effects. Nests C and D are used to assess the impact of the surface barrier on soil-moisture conditions beneath it. Monitoring began in September 2006 and continues to the present. To date, the monitoring system has provided high-quality data. Results show that the soil beneath the barrier has been draining from the shallower depth. The lack of climate-caused seasonal variation of soil water condition beneath the barrier indicates that the surface barrier has minimized water exchange between the soil and the atmosphere.

Vadose zone drilling at the NTS

International Nuclear Information System (INIS)

Efurd, D.W.

1994-01-01

The Yucca Mountain Project has an opportunity to evaluate possible mobilization and transport of radioactive materials away from the storage horizon in the proposed repository. One scenario by which such transport could occur involves water leaving the storage area and carrying radioactive particulates of colloidal size. The colloids could move along the gas-liquid interface in partially filled fractures within the vadose zone. It should be possible to check the reality of this proposed scenario by examining ''anthropogenic analogs'' of the repository. These are sites of nuclear tests conducted in unsaturated tuff at the Nevada Test Site (NTS). We propose to drill under one or more such sites to determine if radionuclides have moved from their original confinement in the puddle- glass at the bottom of the cavity. This document examines the characteristics of an ideal test site for such a study, suggests several possible locations that have some of the desired characteristics, and recommends one of these sites for the proposed drilling

LNAPL infiltration in the vadose zone: Comparisons of physical and numerical simulations

Energy Technology Data Exchange (ETDEWEB)

Pantazidou, M. [Carnegie Mellon Univ., Pittsburgh, PA (United States)

1995-03-01

The numerical model T2VOC was used to reproduce light, nonaqueous phase liquid (LNAPL) infiltration scenarios in the vadose zone. The numerical modeling results were compared to results from laboratory experiments simulating LNAPL spills in the vadose zone. Laboratory measurements included results from one-dimensional column and two-dimensional tank experiments using uniform sands of varying average grain sizes. The constitutive relationships for the sands were obtained from the one-dimensional experiments. The two-dimensional experiments simulated leakage of kerosene under constant head. The sensitivity of the numerical results to the constitutive relationships used and the specified boundary conditions was examined. For this purpose two different capillary pressure-saturation relationships were used for the same sand and both constant head and constant flux conditions were obtained for the two capillary pressure curves used. The constant flux boundary conditions produced a much better prediction. At the initial stages of infiltration the results for both capillary pressure curves were similar and in good agreement with the experimental results. However, as the LNAPL front approaches the capillary fringe the choice of the capillary pressure curve was found to influence the results.

Automated Passive Capillary Lysimeters for Estimating Water Drainage in the Vadose Zone

Science.gov (United States)

Jabro, J.; Evans, R.

2009-04-01

In this study, we demonstrated and evaluated the performance and accuracy of an automated PCAP lysimeters that we designed for in-situ continuous measuring and estimating of drainage water below the rootzone of a sugarbeet-potato-barley rotation under two irrigation frequencies. Twelve automated PCAPs with sampling surface dimensions of 31 cm width * 91 cm long and 87 cm in height were placed 90 cm below the soil surface in a Lihen sandy loam. Our state-of-the-art design incorporated Bluetooth wireless technology to enable an automated datalogger to transmit drainage water data simultaneously every 15 minutes to a remote host and had a greater efficiency than other types of lysimeters. It also offered a significantly larger coverage area (2700 cm2) than similarly designed vadose zone lysimeters. The cumulative manually extracted drainage water was compared with the cumulative volume of drainage water recorded by the datalogger from the tipping bucket using several statistical methods. Our results indicated that our automated PCAPs are accurate and provided convenient means for estimating water drainage in the vadose zone without the need for costly and manually time-consuming supportive systems.

A vadose zone Transport Processes Investigation within the glacial till at the Fernald Environmental Management Project

International Nuclear Information System (INIS)

Schwing, J.; Roepke, Craig Senninger; Brainard, James Robert; Glass, Robert John Jr.; Mann, Michael J.A.; Holt, Robert M..; Kriel, Kelly

2007-01-01

This report describes a model Transport Processes Investigation (TPI) where field-scale vadose zone flow and transport processes are identified and verified through a systematic field investigation at a contaminated DOE site. The objective of the TPI is to help with formulating accurate conceptual models and aid in implementing rational and cost effective site specific characterization strategies at contaminated sites with diverse hydrogeologic settings. Central to the TPI are Transport Processes Characterization (TPC) tests that incorporate field surveys and large-scale infiltration experiments. Hypotheses are formulated based on observed pedogenic and hydrogeologic features as well as information provided by literature searches. The field and literature information is then used to optimize the design of one or more infiltration experiments to field test the hypothesis. Findings from the field surveys and infiltration experiments are then synthesized to formulate accurate flow and transport conceptual models. Here we document a TPI implemented in the glacial till vadose zone at the Fernald Environmental Management Project (FEMP) in Fernald, Ohio, a US Department of Energy (DOE) uranium processing site. As a result of this TPI, the flow and transport mechanisms were identified through visualization of dye stain within extensive macro pore and fracture networks which provided the means for the infiltrate to bypass potential aquatards. Such mechanisms are not addressed in current vadose zone modeling and are generally missed by classical characterization methods

Vadose zone process that control landslide initiation and debris flow propagation

Science.gov (United States)

Sidle, Roy C.

2015-04-01

Advances in the areas of geotechnical engineering, hydrology, mineralogy, geomorphology, geology, and biology have individually advanced our understanding of factors affecting slope stability; however, the interactions among these processes and attributes as they affect the initiation and propagation of landslides and debris flows are not well understood. Here the importance of interactive vadose zone processes is emphasized related to the mechanisms, initiation, mode, and timing of rainfall-initiated landslides that are triggered by positive pore water accretion, loss of soil suction and increase in overburden weight, and long-term cumulative rain water infiltration. Both large- and small-scale preferential flow pathways can both contribute to and mitigate instability, by respectively concentrating and dispersing subsurface flow. These mechanisms are influenced by soil structure, lithology, landforms, and biota. Conditions conducive to landslide initiation by infiltration versus exfiltration are discussed relative to bedrock structure and joints. The effects of rhizosphere processes on slope stability are examined, including root reinforcement of soil mantles, evapotranspiration, and how root structures affect preferential flow paths. At a larger scale, the nexus between hillslope landslides and in-channel debris flows is examined with emphasis on understanding the timing of debris flows relative to chronic and episodic infilling processes, as well as the episodic nature of large rainfall and related stormflow generation in headwater streams. The hydrogeomorphic processes and conditions that determine whether or not landslides immediately mobilize into debris flows is important for predicting the timing and extent of devastating debris flow runout in steep terrain. Given the spatial footprint of individual landslides, it is necessary to assess vadose zone processes at appropriate scales to ascertain impacts on mass wasting phenomena. Articulating the appropriate

Electrical Conductivity in the Vadose Zone beneath a Tamarisk Grove along the Virgin River in Nevada

Science.gov (United States)

Shillito, R.; Sueki, S.; Berli, M.; Healey, J. M.; Acharya, K.

2013-12-01

Thick tamarisk groves along river corridors of the Southwest can transpire vast quantities of water and, as an invasive species, compete with native plants for space and resources. It is hypothesized that tamarisk can outcompete other species by not only tolerating high soil salinity, but by increasing soil salinity due to transpiration of salt-rich near-surface groundwater. The goal of this study was to garner experimental evidence for salt accumulation around tamarisk trees in comparison with other species (mesquite) along the Virgin River near Riverside, NV. At the experimental site, electrical conductivity (EC), temperature (T), and volumetric water content (VWC) within the vadose zone were monitored using sensors at 20, 40, 60, 80 and 100 cm depth on 30-minute intervals within the tamarisk thicket where several mesquite trees are found. Nearby groundwater levels were monitored every 40 days. The 2012 - 2013 data reveal an unexpected EC profile between the surface and the groundwater table (average depth 100 cm). A crust was found within depressions on the surface with EC values as high as 18.8 mS/cm. In the vadose zone (0 to 80 cm depth), average EC values of 4.4 mS/cm were recorded. Most interestingly, in the capillary fringe immediately above the water table (80 to 100 cm depth) average EC values of only 1.25 mS/cm were found whereas the groundwater (>100 cm depth) showed considerably higher EC values averaging 8.8 mS/cm. Additionally, the surface beneath the tamarisk had double the EC as that beneath the mesquite. The contrast in the EC indicates an increase in the aquifer salinity, which may be due to leachate infiltration through the vadose zone concentrated by plant transpiration and direct deposition of saline tamarisk leaf litter and secretions onto the understory. Evapotranspiration and shedding of litter by the tamarisk accelerated the salinity concentrations in the uppermost part of the vadose zone. Ultimately, understanding the salinity regime as

Fingerprints of zones in boreholes. An approach to identify the characteristics of structures

Energy Technology Data Exchange (ETDEWEB)

Straeng, Thomas; Waenstedt, Stefan; Tiren, Sven (GEOSIGMA AB (Sweden))

2010-11-15

The classification of geophysical borehole data in order to identify and characterize structures, which intercepts the borehole, is an important part of 3D modelling of the structural pattern of the bedrock. The objective of this study is to test a statistical approach, cluster analysis, on site data in order to see if it is possible to classify complex data set, geological and geophysical borehole data, in order to identify borehole intersects with increased brittle deformation, i.e. brittle deformation zones. The base data used in the study have been provided and delivered by SKB and consist of borehole logging data from the cored borehole KFM03A. The statistical method chosen for this study, cluster analysis using K-means method, groups data into a pre-defined number of clusters with the goal to minimize the variance of data within the group and to maximize the variance between the clusters. The idea is that data can and should be grouped into two categories, two clusters -corresponding to homogeneous bedrock (matrix) in one cluster and open fractures in the other cluster. The analysis also includes a repetition of the cluster analysis, with a stepwise refined data set to see whether strongly accentuated features could be identified. The results show that the use of K-mean Cluster analysis will present clusters that could represent the spatial distribution of bedrock matrix and the location of fractures respectively down the borehole. The results were compared with fracture frequency data (from core mapping) and also with the geological Single Hole Interpretation of KFM03A performed by SKB. The fracture zones identified in the Single Hole Interpretation process are all indicated in the cluster analysis results. The cluster analysis revealed eight additional possible zones. A majority of these are smaller than 5 metres (section width in the borehole) but they are still pronounced in the analysis. Based on the geophysical data, these sections should be taken into

Vadose Zone Modeling Workshop proceedings, March 29--30, 1993

International Nuclear Information System (INIS)

Khaleel, R.

1993-08-01

At the Hanford Site, the record of decision for remediation of CERCLA sites is largely based on results of the baseline risk and performance assessment of the remedial action alternatives. These assessments require the ability to predict the fate and transport of contaminants along appropriate exposure pathways which, in case of the Hanford Site, includes the migration of contaminants through the vadose zone to the water table. Listed below are some of the requirements, as prescribed by the regulators, relative to CERCLA risk and performance assessment at Hanford. A workshop was organized by the Environmental Risk and Performance Assessment Group, Westinghouse Hanford Company on March 29--30, 1993 at the Richland Best Western Tower Inn. During the workshop, an assessment was made of the need for and scope of various tasks being conducted or planned as part of the Hanford Site waste isolation performance assessment/risk assessment activities. Three external, nationally-recognized experts served as part of a review panel for the workshop: (a) Professor Lynn Gelhar of MIT; (b) Professor Peter Wierenga of University of Arizona; and (c) Dr. Rien van Genuchten of US Salinity Laboratory, Riverside, California. The technical experts provided their perspectives on the current state-of-the-art in vadose zone flow and transport modeling. In addition, the technical experts provided an outside independent assessment of the work being performed or planned in support of various activities identified in TPA Milestone M-29-02. This document includes the following: Recommendations from the three peer reviewers; areas of expertise of the three peer reviewers; workshop agenda; copies of viewgraphs (where available) from presenters at the workshop; workshop minutes; and list of workshop attendees

Geochemical Processes Data Package for the Vadose Zone in the Single-Shell Tank Waste Management Areas at the Hanford Site

Energy Technology Data Exchange (ETDEWEB)

Cantrell, Kirk J.; Zachara, John M.; Dresel, P. Evan; Krupka, Kenneth M.; Serne, R. Jeffrey

2007-09-28

This data package discusses the geochemistry of vadose zone sediments beneath the single-shell tank farms at the U.S. Department of Energy’s (DOE’s) Hanford Site. The purpose of the report is to provide a review of the most recent and relevant geochemical process information available for the vadose zone beneath the single-shell tank farms and the Integrated Disposal Facility. Two companion reports to this one were recently published which discuss the geology of the farms (Reidel and Chamness 2007) and groundwater flow and contamination beneath the farms (Horton 2007).

Remediation of Deep Vadose Zone Radionuclide and Metal Contamination: Status and Issues

Energy Technology Data Exchange (ETDEWEB)

Dresel, P. Evan; Truex, Michael J.; Cantrell, Keri

2008-12-30

This report documents the results of a PNNL literature review to report on the state of maturity of deep vadose zone remediation technologies for metal contaminants including some radionuclides. Its recommendations feed into decisionmakers need for scientific information and cost-effective in situ remediation technlogies needed under DOE's Environmental Management initiative Enhanced Remediation Methods: Scientific & Technical Basis for In Stu Treatment Systems for Metals and Radionuclides.

Unintentional contaminant transfer from groundwater to the vadose zone during source zone remediation of volatile organic compounds.

Science.gov (United States)

Chong, Andrea D; Mayer, K Ulrich

2017-09-01

Historical heavy use of chlorinated solvents in conjunction with improper disposal practices and accidental releases has resulted in widespread contamination of soils and groundwater in North America and worldwide. As a result, remediation of chlorinated solvents is required at many sites. For source zone treatment, common remediation strategies include in-situ chemical oxidation (ISCO) using potassium or sodium permanganate, and the enhancement of biodegradation by primary substrate addition. It is well known that these remediation methods tend to generate gas (carbon dioxide (CO 2 ) in the case of ISCO using permanganate, CO 2 and methane (CH 4 ) in the case of bioremediation). Vigorous gas generation in the presence of chlorinated solvents, which are categorized as volatile organic contaminants (VOCs), may cause gas exsolution, ebullition and stripping of the contaminants from the treatment zone. This process may lead to unintentional 'compartment transfer', whereby VOCs are transported away from the contaminated zone into overlying clean sediments and into the vadose zone. To this extent, benchtop column experiments were conducted to quantify the effect of gas generation during remediation of the common chlorinated solvent trichloroethylene (TCE/C 2 Cl 3 H). Both ISCO and enhanced bioremediation were considered as treatment methods. Results show that gas exsolution and ebullition occurs for both remediation technologies. Facilitated by ebullition, TCE was transported from the source zone into overlying clean groundwater and was subsequently released into the column headspace. For the case of enhanced bioremediation, the intermediate degradation product vinyl chloride (VC) was also stripped from the treatment zone. The concentrations measured in the headspace of the columns (TCE ∼300ppm in the ISCO column, TCE ∼500ppm and VC ∼1380ppm in the bioremediation column) indicate that substantial transfer of VOCs to the vadose zone is possible. These findings

Performance Evaluation of Automated Passive Capillary Sampler for Estimating Water Drainage in the Vadose Zone

Science.gov (United States)

Passive capillary samplers (PCAPs) are widely used to monitor, measure and sample drainage water under saturated and unsaturated soil conditions in the vadose zone. The objective of this study was to evaluate the performance and accuracy of automated passive capillary sampler for estimating drainage...

Scale-Up Information for Gas-Phase Ammonia Treatment of Uranium in the Vadose Zone at the Hanford Site Central Plateau

Energy Technology Data Exchange (ETDEWEB)

Truex, Michael J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Szecsody, James E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Zhong, Lirong [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Thomle, Jonathan N. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Johnson, Timothy C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2014-09-01

Uranium is present in the vadose zone at the Hanford Central Plateau and is of concern for protection of groundwater. The Deep Vadose Zone Treatability Test Plan for the Hanford Central Plateau identified gas-phase treatment and geochemical manipulation as potentially effective treatment approaches for uranium and technetium in the Hanford Central Plateau vadose zone. Based on laboratory evaluation, use of ammonia vapor was selected as the most promising uranium treatment candidate for further development and field testing. While laboratory tests have shown that ammonia treatment effectively reduces the mobility of uranium, additional information is needed to enable deployment of this technology for remediation. Of importance for field applications are aspects of the technology associated with effective distribution of ammonia to a targeted treatment zone, understanding the fate of injected ammonia and its impact on subsurface conditions, and identifying effective monitoring approaches. In addition, information is needed to select equipment and operational parameters for a field design. As part of development efforts for the ammonia technology for remediation of vadose zone uranium contamination, field scale-up issues were identified and have been addressed through a series of laboratory and modeling efforts. This report presents a conceptual description for field application of the ammonia treatment process, engineering calculations to support treatment design, ammonia transport information, field application monitoring approaches, and a discussion of processes affecting the fate of ammonia in the subsurface. The report compiles this information from previous publications and from recent research and development activities. The intent of this report is to provide technical information about these scale-up elements to support the design and operation of a field test for the ammonia treatment technology.

The effect of vadose zone heterogeneities on vapor phase migration and aquifer contamination by volatile organics

Energy Technology Data Exchange (ETDEWEB)

Seneviratne, A.; Findikakis, A.N. [Bechtel Corporation, San Francisco, CA (United States)

1995-03-01

Organic vapors migrating through the vadose zone and inter-phase transfer can contribute to the contamination of larger portions of aquifers than estimated by accounting only for dissolved phase transport through the saturated zone. Proper understanding of vapor phase migration pathways is important for the characterization of the extent of both vadose zone and the saturated zone contamination. The multiphase simulation code T2VOC is used to numerically investigate the effect of heterogeneties on the vapor phase migration of chlorobenzene at a hypothetical site where a vapor extraction system is used to remove contaminants. Different stratigraphies consisting of alternate layers of high and low permeability materials with soil properties representative of gravel, sandy silt and clays are evaluated. The effect of the extent and continuity of low permeability zones on vapor migration is evaluated. Numerical simulations are carried out for different soil properties and different boundary conditions. T2VOC simulations with zones of higher permeability were made to assess the role of how such zones in providing enhanced migration pathways for organic vapors. Similarly, the effect of the degree of saturation of the porous medium on vapor migration was for a range of saturation values. Increased saturation reduces the pore volume of the medium available for vapor diffusion. Stratigraphic units with higher aqueous saturation can retard the vapor phase migration significantly.

Aerosol Delivery for Amendment Distribution in Contaminated Vadose Zones

Science.gov (United States)

Hall, R. J.; Murdoch, L.; Riha, B.; Looney, B.

2011-12-01

Remediation of contaminated vadose zones is often hindered by an inability to effectively distribute amendments. Many amendment-based approaches have been successful in saturated formations, however, have not been widely pursued when treating contaminated unsaturated materials due to amendment distribution limitations. Aerosol delivery is a promising new approach for distributing amendments in contaminated vadose zones. Amendments are aerosolized and injected through well screens. During injection the aerosol particles are transported with the gas and deposited on the surfaces of soil grains. Resulting distributions are radially and vertically broad, which could not be achieved by injecting pure liquid-phase solutions. The objectives of this work were A) to characterize transport and deposition behaviors of aerosols; and B) to develop capabilities for predicting results of aerosol injection scenarios. Aerosol transport and deposition processes were investigated by conducting lab-scale injection experiments. These experiments involved injection of aerosols through a 2m radius, sand-filled wedge. A particle analyzer was used to measure aerosol particle distributions with time, and sand samples were taken for amendment content analysis. Predictive capabilities were obtained by constructing a numerical model capable of simulating aerosol transport and deposition in porous media. Results from tests involving vegetable oil aerosol injection show that liquid contents appropriate for remedial applications could be readily achieved throughout the sand-filled wedge. Lab-scale tests conducted with aqueous aerosols show that liquid accumulation only occurs near the point of injection. Tests were also conducted using 200 g/L salt water as the aerosolized liquid. Liquid accumulations observed during salt water tests were minimal and similar to aqueous aerosol results. However, particles were measured, and salt deposited distal to the point of injection. Differences between

Conceptual Models for Migration of Key Groundwater Contaminants Through the Vadose Zone and Into the Upper Unconfined Aquifer Below the B-Complex

Energy Technology Data Exchange (ETDEWEB)

Serne, R. Jeffrey; Bjornstad, Bruce N.; Keller, Jason M.; Thorne, Paul D.; Lanigan, David C.; Christensen, J. N.; Thomas, Gregory S.

2010-07-01

The B-Complex contains 3 major crib and trench disposal sites and 3 SST farms that have released nearly 346 mega-liters of waste liquids containing the following high groundwater risk drivers: ~14,000 kg of CN, 29,000 kg of Cr, 12,000 kg of U and 145 Ci of Tc-99. After a thorough review of available vadose zone sediment and pore water, groundwater plume, field gamma logging, field electrical resistivity studies, we developed conceptual models for which facilities have been the significant sources of the contaminants in the groundwater and estimated the masses of these contaminants remaining in the vadose zone and currently present in the groundwater in comparison to the totals released. This allowed us to make mass balance calculations on how consistent our knowledge is on the current deep vadose zone and groundwater distribution of contaminants. Strengths and weaknesses of the conceptual models are discussed as well as implications on future groundwater and deep vadose zone remediation alternatives. Our hypothesized conceptual models attribute the source of all of the cyanide and most of the Tc-99 currently in the groundwater to the BY cribs. The source of the uranium is the BX-102 tank overfill event and the source of most of the chromium is the B-7-A&B and B-8 cribs. Our mass balance estimates suggest that there are much larger masses of U, CN, and Tc remaining in the deep vadose zone within ~20 ft of the water table than is currently in the groundwater plumes below the B-Complex. This hypothesis needs to be carefully considered before future remediation efforts are chosen. The masses of these groundwater risk drivers in the the groundwater plumes have been increasing over the last decade and the groundwater plumes are migrating to the northwest towards the Gable Gap. The groundwater flow rate appears to flucuate in response to seasonal changes in hydraulic gradient. The flux of contaminants out of the deep vadose zone from the three proposed sources also

Imaging groundwater infiltration dynamics in the karst vadose zone with long-term ERT monitoring

Directory of Open Access Journals (Sweden)

A. Watlet

2018-03-01

Full Text Available Water infiltration and recharge processes in karst systems are complex and difficult to measure with conventional hydrological methods. In particular, temporarily saturated groundwater reservoirs hosted in the vadose zone can play a buffering role in water infiltration. This results from the pronounced porosity and permeability contrasts created by local karstification processes of carbonate rocks. Analyses of time-lapse 2-D geoelectrical imaging over a period of 3 years at the Rochefort Cave Laboratory (RCL site in south Belgium highlight variable hydrodynamics in a karst vadose zone. This represents the first long-term and permanently installed electrical resistivity tomography (ERT monitoring in a karst landscape. The collected data were compared to conventional hydrological measurements (drip discharge monitoring, soil moisture and water conductivity data sets and a detailed structural analysis of the local geological structures providing a thorough understanding of the groundwater infiltration. Seasonal changes affect all the imaged areas leading to increases in resistivity in spring and summer attributed to enhanced evapotranspiration, whereas winter is characterised by a general decrease in resistivity associated with a groundwater recharge of the vadose zone. Three types of hydrological dynamics, corresponding to areas with distinct lithological and structural features, could be identified via changes in resistivity: (D1 upper conductive layers, associated with clay-rich soil and epikarst, showing the highest variability related to weather conditions; (D2 deeper and more resistive limestone areas, characterised by variable degrees of porosity and clay contents, hence showing more diffuse seasonal variations; and (D3 a conductive fractured zone associated with damped seasonal dynamics, while showing a great variability similar to that of the upper layers in response to rainfall events. This study provides detailed images of

Application of vadose-zone monitoring system for real-time characterization of leachate percolation in and under a municipal landfill.

Science.gov (United States)

Aharoni, Imri; Siebner, Hagar; Dahan, Ofer

2017-09-01

Leachates from solid-waste landfills are considered a severe threat to groundwater quality. The fate of pollutants in the waste and underlying unsaturated zone is crucial for evaluating environmental risks and selecting a restoration strategy. In this study, a vadose-zone monitoring system (VMS) installed in a municipal landfill was used, for the first time, to continuously track leachates percolation dynamics and assess their chemical transformation across the entire thickness of the waste body (15m) and underlying unsaturated zone (16m) to the water table. Winter rains were found to quickly infiltrate through the waste and underlying vadose zone despite a clay cover that was implemented as part of a restoration and leachate-prevention strategy. Within the waste body, the flow pattern was controlled by preferential flow paths, which changed frequently. It is hypothesized that ongoing decomposition of the waste creates dynamic variations in the waste's physical structure and flow pattern. Water samples collected from the waste layer indicated the formation of highly polluted leachates. The chemical composition in the waste body showed extreme variability between sampling points with respect to DOC (407-31,464mg/L), BOD/COD ratios (0.07-0.55), Fe 2+ (6.8-1154mg/L), ammonium (68-2924mg/L) and heavy metal concentrations. Environmental hot spots creating concentrated, aggressive, "acid-phase" leachates still exist in the waste more than 13years after closing the landfill. However, continuous changes in the flow pattern and moisture distribution affected the creation and decay of such environments. In the underlying sandy vadose zone, some sections repeatedly exhibited stronger and faster flow characteristics than others. These local fluxes of concentrated leachates rapidly transported heavy contaminant loads toward the groundwater. However results showed evidence of continual attenuation processes in the deep vadose zone, with the anaerobic digestion of organic matter

In-situ bioaugmentation of vadose zone restoration

International Nuclear Information System (INIS)

Myers, J.M.; Minkel, K.A.; Schepart, B.S.

1992-01-01

Leakage from an underground gasoline storage tank caused evacuation from a restaurant and an insurance company. An engineering consultant was engaged to correct the problem. Upon remedy of the habitability situation, a groundwater recovery system was designed to recover whatever open-quotes free productclose quotes gasoline could be collected. Since traditional open-quotes Pump and treatclose quotes remedial technologies are successful only to the extent that the contaminant is mobile, an alternative is necessary to effectively remediate that contamination which is recalcitrant. At this point, Waste Stream Technology was enlisted to propose an in-situ remedial action plan. Approximately five injection wells were installed around the perimeter and in the zone of influence of each of eight recovery wells. The injection wells were designed to distribute the bacteria at various depths in the vadose zone. Bacteria were cultured on site in Waste Stream's proprietary bioreactor. Bacterial and nutrient applications were injected on a weekly basis. Bacterial population dynamics and BETX levels were monitored throughout the course of the remediation. Although the remediation is currently in progress, disappearance of open-quotes free productclose quotes on the water table and elimination of benzene in the groundwater over a reasonable time period marked the success of this project

Characterization Activities to Determine the Extent of DNAPL in the Vadose Zone at the A-014 Outfall of A/M Area

International Nuclear Information System (INIS)

Jackson, D.G.

2000-01-01

The purpose of this investigation was to perform characterization activities necessary to confirm the presence and extent of DNAPL in the shallow vadose zone near the headwaters of the A-014 Outfall. Following the characterization, additional soil vapor extraction wells and vadose monitoring probes were installed to promote and monitor remediation activities in regions of identified DNAPL

Experimental and Numerical Investigations of Soil Desiccation for Vadose Zone Remediation: Report for Fiscal Year 2007

Energy Technology Data Exchange (ETDEWEB)

Ward, Andy L.; Oostrom, Mart; Bacon, Diana H.

2008-02-04

Apart from source excavation, the options available for the remediation of vadose zone metal and radionuclide contaminants beyond the practical excavation depth (0 to 15 m) are quite limited. Of the available technologies, very few are applicable to the deep vadose zone with the top-ranked candidate being soil desiccation. An expert panel review of the work on infiltration control and supplemental technologies identified a number of knowledge gaps that would need to be overcome before soil desiccation could be deployed. The report documents some of the research conducted in the last year to fill these knowledge gaps. This work included 1) performing intermediate-scale laboratory flow cell experiments to demonstrate the desiccation process, 2) implementing a scalable version of Subsurface Transport Over Multiple Phases–Water-Air-Energy (STOMP-WAE), and 3) performing numerical experiments to identify the factors controlling the performance of a desiccation system.

A Low-Level Real-Time In Situ Monitoring System for Tritium in Groundwater and Vadose Zone

Science.gov (United States)

Santo, J. T.; Levitt, D. G.

2002-12-01

Tritium is a radioactive isotope of hydrogen produced as a by-product of the nuclear fuel cycle. It is also an integral part of the nuclear weapons industry and has been released into the environment through both the production and testing of nuclear weapons. There are many sites across the DOE complex where tritium has been released into the subsurface through the disposal of radioactive waste and at the Nevada Test Site, through the underground testing of nuclear weapons. Numerous DOE facilities have an on-going regulatory need to be able to monitor tritium concentrations in groundwater within deep hydrologic zones and in the shallower non-saturated vadose zone beneath waste disposal pits and shafts and other release sites. Typical access to groundwater is through deep monitoring wells and situated in remote locations. In response to this need, Science and Engineering Associates, Inc. (SEA) and its subcontractor, the University of Nevada Las Vegas (UNLV) Harry Reid Center (HRC) for Environmental Studies has conducted the applied research and engineering and produced a real time, in situ monitoring system for the detection and measurement of low levels of tritium in the groundwater and in the shallower vadose zone. The monitoring system has been deployed to measure tritium in both the vadose zone near a subsurface radioactive waste package and the groundwater in a deep hydrologic reservoir at the Nevada Test Site. The monitoring system has been designed to detect tritium in the subsurface below federal and/or state regulatory limits for safe drinking water and has been successfully demonstrated. The development effort is being funded through the U.S. Department of Energy, National Energy Technology Laboratory and the DOE Nevada Operations Office Advanced Monitoring Systems Initiative (AMSI).

Significance of water fluxes in a deep arid-region vadose zone to waste disposal strategies

International Nuclear Information System (INIS)

Johnejack, K.R.; Blout, D.O.; Sully, M.J.; Emer, D.F.; Hammermeister, D.P.; Dever, L.G.; O'Neill, L.J.; Tyler, S.W.; Chapman, J.

1994-01-01

Recently collected subsurface site characterization data have led to the development of a conceptual model of water movement beneath the Area 5 Radioactive Waste Management Site (RWMS) at the Nevada Test Site (NTS) that differs significantly from the conceptual model of water movement inherent in Resource Conservation and Recovery Act (RCRA) regulations. At the Area 5 RWMS, water fluxes in approximately the upper 75 m (250 ft) of the vadose zone point in the upward direction (rather than downward) which effectively isolates this region from the deep (approximately 250 m (820 ft)) uppermost aquifer. Standard RCRA approaches for detection and containment (groundwater monitoring and double liners/leachate collection/leak detection systems) are not able to fulfill their intended function in this rather unique hydrogeologic environment. In order to better fulfill the waste detection and containment intentions of RCRA for mixed waste disposal at the Area 5 RWMS, the Department of Energy, Nevada Operations Office (DOE/NV) is preparing a single petition for both a waiver from groundwater monitoring and an exemption from double liners with leachate collection/leak detection. DOE/NV proposes in this petition that the containment function of liners and leachate collection is better accomplished by the natural hydrogeologic processes operating in the upper vadose zone; and the detection function of groundwater monitoring and the leak detection system in liners is better fulfilled by an alternative vadose zone monitoring system. In addition, an alternative point of compliance is proposed that will aid in early detection, as well as limit the extent of potential contamination before detection. Finally, special cell design features and operation practices will be implemented to limit leachate formation, especially while the cell is open to the atmosphere during waste emplacement

Analysing the mechanisms of soil water and vapour transport in the desert vadose zone of the extremely arid region of northern China

Science.gov (United States)

Du, Chaoyang; Yu, Jingjie; Wang, Ping; Zhang, Yichi

2018-03-01

The transport of water and vapour in the desert vadose zone plays a critical role in the overall water and energy balances of near-surface environments in arid regions. However, field measurements in extremely dry environments face many difficulties and challenges, so few studies have examined water and vapour transport processes in the desert vadose zone. The main objective of this study is to analyse the mechanisms of soil water and vapour transport in the desert vadose zone (depth of ∼350 cm) by using measured and modelled data in an extremely arid environment. The field experiments are implemented in an area of the Gobi desert in northwestern China to measure the soil properties, daily soil moisture and temperature, daily water-table depth and temperature, and daily meteorological records from DOYs (Days of Year) 114-212 in 2014 (growing season). The Hydrus-1D model, which simulates the coupled transport of water, vapour and heat in the vadose zone, is employed to simulate the layered soil moisture and temperature regimes and analyse the transport processes of soil water and vapour. The measured results show that the soil water and temperatures near the land surface have visible daily fluctuations across the entire soil profile. Thermal vapour movement is the most important component of the total water flux and the soil temperature gradient is the major driving factor that affects vapour transport in the desert vadose zone. The most active water and heat exchange occurs in the upper soil layer (depths of 0-25 cm). The matric potential change from the precipitation mainly re-draws the spatio-temporal distribution of the isothermal liquid water in the soil near the land surface. The matric potential has little effect on the isothermal vapour and thermal liquid water flux. These findings offer new insights into the liquid water and vapour movement processes in the extremely arid environment.

DNAPL Surface Chemistry: Its Impact on DNAPL Distribution in the Vadose Zone and its Manipulation to Enhance Remediation

Energy Technology Data Exchange (ETDEWEB)

Suan Power; Stefan Grimberg; Miles Denham

2003-06-16

The remediation of DNAPLs in subsurface environments is often limited by the heterogeneous distribution of the organic fluid. The fraction of DNAPL that is in the high conductivity regions of the subsurface can often be recovered relatively easily, although DNAPL in lower conductivity regions is much more difficult to extract, either through direct pumping or remediation measures based on interface mass transfer. The distribution of DNAPL within the vadose zone is affected by a complex interplay of heterogeneities in the porous matrix and the interfacial properties defining the interactions among all fluid and solid phases. Decreasing the interfacial tension between a DNAPL and water in the vadose zone could change the spreading of the DNAPL, thereby increase the surface area for mass transfer and the effectiveness of soil vapor extraction remediation.

In-situ active/passive bioreclamation of vadose zone soils contaminated with gasoline and waste oil using soil vapor extraction/bioventing: Laboratory pilot study to full scale site operation

International Nuclear Information System (INIS)

Zachary, S.P.; Everett, L.G.

1993-01-01

The use of soil venting to supply oxygen and remove metabolites from the biodegradation of light hydrocarbons is a cost effective in-situ remediation approach. To date, little data exists on the effective in-situ bioreclamation of vadose zone soil contaminated with waste/hydraulic oil without excavation or the addition of water or nutrients to degrade the heavy petroleum contaminants. Gasoline and waste/hydraulic oil contaminated soils below an active commercial building required an in-situ non-disruptive remediation approach. Initial soil vapor samples collected from the vadose zone revealed CO 2 concentrations in excess of 16% and O 2 concentrations of less than 1% by volume. Soil samples were collected from below the building within the contaminated vadose zone for laboratory chemical and physical analysis as well as to conduct a laboratory biotreatability study. The laboratory biotreatability study was conducted for 30 days to simulate vadose zone bioventing conditions using soil taken from the contaminated vadose zone. Results of the biotreatability study revealed that the waste oil concentrations had been reduced from 960 mg/Kg to non-detectable concentrations within 30 days and the volatile hydrocarbon content had decreased exponentially to less than 0.1% of the original concentration. Post treatability study biological enumeration revealed an increase in the microbial population of two orders of magnitude

Borehole Calibration Facilities to Support Gamma Logging for Hanford Subsurface Investigation and Contaminant Monitoring - 13516

International Nuclear Information System (INIS)

McCain, R.G.; Henwood, P.D.; Pope, A.D.; Pearson, A.W.

2013-01-01

Repeated gamma logging in cased holes represents a cost-effective means to monitor gamma-emitting contamination in the deep vadose zone over time. Careful calibration and standardization of gamma log results are required to track changes and to compare results over time from different detectors and logging systems. This paper provides a summary description of Hanford facilities currently available for calibration of logging equipment. Ideally, all logging organizations conducting borehole gamma measurements at the Hanford Site will take advantage of these facilities to produce standardized and comparable results. (authors)

Borehole Calibration Facilities to Support Gamma Logging for Hanford Subsurface Investigation and Contaminant Monitoring - 13516

Energy Technology Data Exchange (ETDEWEB)

McCain, R.G.; Henwood, P.D.; Pope, A.D.; Pearson, A.W. [S M Stoller Corporation, 2439 Robertson Drive, Richland, WA 99354 (United States)

2013-07-01

Repeated gamma logging in cased holes represents a cost-effective means to monitor gamma-emitting contamination in the deep vadose zone over time. Careful calibration and standardization of gamma log results are required to track changes and to compare results over time from different detectors and logging systems. This paper provides a summary description of Hanford facilities currently available for calibration of logging equipment. Ideally, all logging organizations conducting borehole gamma measurements at the Hanford Site will take advantage of these facilities to produce standardized and comparable results. (authors)

An isotopic view of water and nitrate transport through the vadose zone in Oregon's southern Willamette Valley's Groundwater Management Area

Science.gov (United States)

Brooks, J. R.; Pearlstein, S.; Hutchins, S.; Faulkner, B. R.; Rugh, W.; Willard, K.; Coulombe, R.; Compton, J.

2017-12-01

Groundwater nitrate contamination affects thousands of households in Oregon's southern Willamette Valley and many more across the USA. The southern Willamette Valley Groundwater Management Area (GWMA) was established in 2004 due to nitrate levels in the groundwater exceeding the human health standard of 10 mg nitrate-N L-1. Much of the nitrogen (N) inputs to the GWMA comes from agricultural fertilizers, and thus efforts to reduce N inputs to groundwater are focused upon improving N management. However, the effectiveness of these improvements on groundwater quality is unclear because of the complexity of nutrient transport through the vadose zone and long groundwater residence times. Our objective was to focus on vadose zone transport and understand the dynamics and timing of N and water movement below the rooting zone in relation to N management and water inputs. Stable isotopes are a powerful tool for tracking water movement, and understanding N transformations. In partnership with local farmers and state agencies, we established lysimeters and groundwater wells in multiple agricultural fields in the GWMA, and have monitored nitrate, nitrate isotopes, and water isotopes weekly for multiple years. Our results indicate that vadose zone transport is highly complex, and the residence time of water collected in lysimeters was much longer than expected. While input precipitation water isotopes were highly variable over time, lysimeter water isotopes were surprisingly consistent, more closely resembling long-term precipitation isotope means rather than recent precipitation isotopic signatures. However, some particularly large precipitation events with unique isotopic signatures revealed high spatial variability in transport, with some lysimeters showing greater proportions of recent precipitation inputs than others. In one installation where we have groundwater wells and lysimeters at multiple depths, nitrate/nitrite concentrations decreased with depth. N concentrations

Calibrating vadose zone models with time-lapse gravity data: a forced infiltration experiment

DEFF Research Database (Denmark)

Christiansen, Lars; Hansen, Allan Bo; Zibar, Majken Caroline Looms

A change in soil water content is a change in mass stored in the subsurface, and when large enough, can be measured with a gravity meter. Over the last few decades there has been increased use of ground-based time-lapse gravity measurements to infer hydrogeological parameters. These studies have...... focused on the saturated zone, with specific yield as the most prominent target parameter and with few exceptions, changes in storage in the vadose zone have been considered as noise. Here modeling results are presented suggesting that gravity changes will be measureable when soil moisture changes occur...... in the unsaturated zone. These results are confirmed by field measurements of gravity and georadar data at a forced infiltration experiment conducted over 14 days on a grassland area of 10 m by 10 m. An unsaturated zone infiltration model can be calibrated using the gravity data with good agreement to the field data...

Electrical Resistivity Correlation to Vadose Zone Sediment and Pore-Water Composition for the BC Cribs and Trenches Area

International Nuclear Information System (INIS)

Serne, R. Jeffrey; Ward, Anderson L.; Um, Wooyong; Bjornstad, Bruce N.; Rucker, Dale F.; Lanigan, David C.; Benecke, Mark W.

2009-01-01

This technical report documents the results of geochemical and soil resistivity characterization of sediment obtained from four boreholes drilled in the BC Cribs and Trench area. Vadose zone sediment samples were obtained at a frequency of about every 2.5 ft from approximately 5 ft bgs to borehole total depth. In total, 505 grab samples and 39 six-inch long cores were obtained for characterization. The pore-water chemical composition data, laboratory-scale soil resistivity and other ancillary physical and hydrologic measurements and analyses described in this report are designed to provide a crucial link between direct measurements on sediments and the surface-based electrical-resistivity information obtained via field surveys. A second goal of the sediment characterization was to measure the total and water-leachable concentrations of key contaminants of concern as a function of depth and distance from the footprints of inactive disposal facilities. The total and water-leachable concentrations of key contaminants will be used to update contaminant distribution conceptual models and to provide more data for improving base-line risk predictions and remedial alternative selections. The ERC 'ground truthing' exercise for the individual boreholes showed mixed results. In general, the high concentrations of dissolved salts in the pore waters of sediments from C5923, C5924 and C4191 produced a low resistivity 'target' in the processed resistivity field surveys, and variability could be seen in the resistivity data that could relate to the variability in pore- water concentrations but the correlations (regression R2 were mediocre ranging from 0.2 to 0.7 at best; where perfect correlation is 1.0). The field-based geophysical data also seemed to suffer from a sort of vertigo, where looking down from the ground surface, the target (e.g., maximum pore-water salt concentration) depth was difficult to resolve. The best correlations between the field electrical resistivity

Electrical Resistivity Correlation to Vadose Zone Sediment and Pore-Water Composition for the BC Cribs and Trenches Area

Energy Technology Data Exchange (ETDEWEB)

Serne, R. Jeffrey; Ward, Anderson L.; Um, Wooyong; Bjornstad, Bruce N.; Rucker, Dale F.; Lanigan, David C.; Benecke, Mark W.

2009-06-01

This technical report documents the results of geochemical and soil resistivity characterization of sediment obtained from four boreholes drilled in the BC Cribs and Trench area. Vadose zone sediment samples were obtained at a frequency of about every 2.5 ft from approximately 5 ft bgs to borehole total depth. In total, 505 grab samples and 39 six-inch long cores were obtained for characterization. The pore-water chemical composition data, laboratory-scale soil resistivity and other ancillary physical and hydrologic measurements and analyses described in this report are designed to provide a crucial link between direct measurements on sediments and the surface-based electrical-resistivity information obtained via field surveys. A second goal of the sediment characterization was to measure the total and water-leachable concentrations of key contaminants of concern as a function of depth and distance from the footprints of inactive disposal facilities. The total and water-leachable concentrations of key contaminants will be used to update contaminant distribution conceptual models and to provide more data for improving base-line risk predictions and remedial alternative selections. The ERC “ground truthing” exercise for the individual boreholes showed mixed results. In general, the high concentrations of dissolved salts in the pore waters of sediments from C5923, C5924 and C4191 produced a low resistivity “target” in the processed resistivity field surveys, and variability could be seen in the resistivity data that could relate to the variability in pore- water concentrations but the correlations (regression R2 were mediocre ranging from 0.2 to 0.7 at best; where perfect correlation is 1.0). The field-based geophysical data also seemed to suffer from a sort of vertigo, where looking down from the ground surface, the target (e.g., maximum pore-water salt concentration) depth was difficult to resolve. The best correlations between the field electrical

Deep Vadose Zone–Applied Field Research Initiative Fiscal Year 2012 Annual Report

Energy Technology Data Exchange (ETDEWEB)

Wellman, Dawn M.; Truex, Michael J.; Johnson, Timothy C.; Bunn, Amoret L.; Golovich, Elizabeth C.

2013-03-14

This annual report describes the background of the Deep Vadose Zone-Applied Field Research Initiative, and some of the programmatic approaches and transformational technologies in groundwater and deep vadose zone remediation developed during fiscal year 2012.

Preliminary study of radioactive waste disposal in the vadose zone

International Nuclear Information System (INIS)

1978-09-01

To investigate the characteristics of the vadose zone with respect to radioactive waste disposal, the mechanics of unsaturated flow in arid regions and the geohydrology of four areas with a deep water table were studied. The studies indicated that (1) arid sites with a water table deeper than 200 m can be found in at least three distinct geologic settings in the western United States, (2) the physics of unsaturated flow in soils and rock with interstitial porosity at low water contents, particularly under thermal gradients, is not yet completely understood, and (3) under certain conditions unsaturated flow can be so slow that analytic modeling of an unflawed repository is unnecessary to prove effective containment

Preliminary study of radioactive waste disposal in the vadose zone

Energy Technology Data Exchange (ETDEWEB)

1978-09-01

To investigate the characteristics of the vadose zone with respect to radioactive waste disposal, the mechanics of unsaturated flow in arid regions and the geohydrology of four areas with a deep water table were studied. The studies indicated that (1) arid sites with a water table deeper than 200 m can be found in at least three distinct geologic settings in the western United States, (2) the physics of unsaturated flow in soils and rock with interstitial porosity at low water contents, particularly under thermal gradients, is not yet completely understood, and (3) under certain conditions unsaturated flow can be so slow that analytic modeling of an unflawed repository is unnecessary to prove effective containment.

Engineering report single-shell tank farms interim measures to limit infiltration through the vadose zone

International Nuclear Information System (INIS)

HAASS, C.C.

1999-01-01

Identifies, evaluates and recommends interim measures for reducing or eliminating water sources and preferential pathways within the vadose zone of the single-shell tank farms. Features studied: surface water infiltration and leaking water lines that provide recharge moisture, and wells that could provide pathways for contaminant migration. An extensive data base, maps, recommended mitigations, and rough order of magnitude costs are included

Engineering report single-shell tank farms interim measures to limit infiltration through the vadose zone

Energy Technology Data Exchange (ETDEWEB)

HAASS, C.C.

1999-10-14

Identifies, evaluates and recommends interim measures for reducing or eliminating water sources and preferential pathways within the vadose zone of the single-shell tank farms. Features studied: surface water infiltration and leaking water lines that provide recharge moisture, and wells that could provide pathways for contaminant migration. An extensive data base, maps, recommended mitigations, and rough order of magnitude costs are included.

Vadose zone processes delay groundwater nitrate reduction response to BMP implementation as observed in paired cultivated vs. uncultivated potato rotation fields

Science.gov (United States)

Jiang, Y.; Nyiraneza, J.; Murray, B. J.; Chapman, S.; Malenica, A.; Parker, B.

2017-12-01

Nitrate leaching from crop production contributes to groundwater contamination and subsequent eutrophication of the receiving surface water. A study was conducted in a 7-ha potato-grain-forages rotation field in Prince Edward Island (PEI), Canada during 2011-2016 to link potato rotation practices and groundwater quality. The field consists of fine sandy loam soil and is underlain by 7-9 m of glacial till, which overlies the regional fractured ;red-bed; sandstone aquifer. The water table is generally located in overburden close to the bedrock interface. Field treatments included one field zone taken out of production in 2011 with the remaining zones kept under a conventional potato rotation. Agronomy data including crop tissue, soil, and tile-drain water quality were collected. Hydrogeology data including multilevel monitoring of groundwater nitrate and hydraulic head and data from rock coring for nitrate distribution in overburden and bedrock matrix were also collected. A significant amount of nitrate leached below the soil profile after potato plant kill (referred to as topkill) in 2011, most of it from fertilizer N. A high level of nitrate was also detected in the till vadose zone through coring in December 2012 and through multilevel groundwater sampling from January to May 2014 in both cultivated and uncultivated field zones. Groundwater nitrate concentrations increased for about 2.5 years after the overlying potato field was removed from production. Pressure-driven uniform flow processes dominate water and nitrate transport in the vadose zone, producing an apparently instant water table response but a delayed groundwater quality response to nitrate leaching events. These data suggest that the uniform flow dominated vadose zone in agricultural landscapes can cause the accumulation of a significant amount of nitrate originated from previous farming activities, and the long travel time of this legacy nitrate in the vadose zone can result in substantially delayed

Site characterization for the in situ bioremediation of the vadose zone

International Nuclear Information System (INIS)

Montemagno, C.D.; Leo, A.; Craig, J.

1993-01-01

Studies were conducted to determine whether bioremediation can be used to treat a diesel fuel spill in the deep vadose zone (>30 m). After laboratory studies confirmed the ability of the natural population of organisms to degrade the diesel fuel, the technological issue of transporting the required mass of nutrients to the contaminated soils was addressed. Laboratory studies demonstrated that nutrient and oxygen transport can be enhanced by the addition of divalent cations to injected waters. This addition of minerals caused the observed hydraulic conductivity to be maintained at elevated levels that allowed the macronutrient nitrogen, provided as ammonium ion, to be more uniformly distributed to target soil domains

Bayesian Markov chain Monte Carlo Inversion of Time-Lapse Geophysical Data To Characterize the Vadose Zone

DEFF Research Database (Denmark)

Scholer, Marie; Irving, James; Zibar, Majken Caroline Looms

Geophysical methods have the potential to provide valuable information on hydrological properties in the unsaturated zone. In particular, time-lapse geophysical data, when coupled with a hydrological model and inverted stochastically, may allow for the effective estimation of subsurface hydraulic...... parameters and their corresponding uncertainties. In this study, we use a Bayesian Markov-chain-Monte-Carlo (MCMC) inversion approach to investigate how much information regarding vadose zone hydraulic properties can be retrieved from time-lapse crosshole GPR data collected at the Arrenaes field site...

Interfacial Reduction-Oxidation Mechanisms Governing Fate and Transport of Contaminants in the Vadose Zone

Energy Technology Data Exchange (ETDEWEB)

Principal Investigator: Baolin Deng, University of Missouri, Columbia, MO; Co-Principal Investigator: Silvia Sabine Jurisson, University of Missouri, Columbia, MO; Co-Principal Investigator: Edward C. Thornton, Pacific Northwest National Laboratory Richland, WA; Co-Principal Investigator: Jeff Terry, Illinois Institute of Technology, Chicago, IL

2008-05-12

There are many soil contamination sites at the Department of Energy (DOE) installations that contain radionuclides and toxic metals such as uranium (U), technetium (Tc), and chromium (Cr). Since these contaminants are the main 'risk drivers' at the Hanford site (WA) and some of them also pose significant risk at other DOE facilities (e.g., Oak Ridge Reservation - TN; Rocky Flats - CO), development of technologies for cost effective site remediation is needed. Current assessment indicates that complete removal of these contaminants for ex-situ disposal is infeasible, thus in-situ stabilization through reduction to insoluble species is considered one of the most important approaches for site remediation. In Situ Gaseous Reduction (ISGR) is a technology developed by Pacific Northwest National Laboratory (PNNL) for vadose zone soil remediation. The ISGR approach uses hydrogen sulfide (H{sub 2}S) for reductive immobilization of contaminants that show substantially lower mobility in their reduced forms (e.g., Tc, U, and Cr). The technology can be applied in two ways: (i) to immobilize or stabilize pre-existing contaminants in the vadose zone soils by direct H{sub 2}S treatment, or (ii) to create a permeable reactive barrier (PRB) that prevents the migration of contaminants. Direct treatment involves reduction of the contaminants by H{sub 2}S to less mobile species. Formation of a PRB is accomplished through reduction of ferric iron species in the vadose zone soils by H{sub 2}S to iron sulfides (e.g., FeS), which provides a means for capturing the contaminants entering the treated zone. Potential future releases may occur during tank closure activities. Thus, the placement of a permeable reactive barrier by ISGR treatment can be part of the leak mitigation program. Deployment of these ISGR approaches, however, requires a better understanding of the immobilization kinetics and mechanisms, and a better assessment of the long-term effectiveness of treatment. The

Natural analogues for processes affecting disposal of high-level radioactive waste in the vadose zone

Science.gov (United States)

Stuckless, J. S.

2003-04-01

Natural analogues can contribute to understanding and predicting the performance of subsystems and processes affecting a mined geologic repository for high-level radioactive waste in several ways. Most importantly, analogues provide tests for various aspects of systems of a repository at dimensional scales and time spans that cannot be attained by experimental study. In addition, they provide a means for the general public to judge the predicted performance of a potential high-level nuclear waste repository in familiar terms such that the average person can assess the anticipated long-term performance and other scientific conclusions. Hydrologists working on the Yucca Mountain Project (currently the U.S. Department of Energy's Office of Repository Development) have modeled the flow of water through the vadose zone at Yucca Mountain, Nevada and particularly the interaction of vadose-zone water with mined openings. Analogues from both natural and anthropogenic examples confirm the prediction that most of the water moving through the vadose zone will move through the host rock and around tunnels. This can be seen both quantitatively where direct comparison between seepage and net infiltration has been made and qualitatively by the excellent degree of preservation of archaeologic artifacts in underground openings. The latter include Paleolithic cave paintings in southwestern Europe, murals and artifacts in Egyptian tombs, painted subterranean Buddhist temples in India and China, and painted underground churches in Cappadocia, Turkey. Natural analogues also suggest that this diversion mechanism is more effective in porous media than in fractured media. Observations from natural analogues are also consistent with the modeled decrease in the percentage of infiltration that becomes seepage with a decrease in amount of infiltration. Finally, analogues, such as tombs that have ben partially filled by mud flows, suggest that the same capillary forces that keep water in the

T-TY Tank Farm Interim Surface Barrier Demonstration - Vadose Zone Monitoring Plan

International Nuclear Information System (INIS)

Zhang, Z.F.; Strickland, Christopher E.; Field, Jim G.; Parker, Danny L.

2010-01-01

The Hanford Site has 149 underground single-shell tanks that store hazardous radioactive waste. Many of these tanks and their associated infrastructure (e.g., pipelines, diversion boxes) have leaked. Some of the leaked waste has entered the groundwater. The largest known leak occurred from the T-106 Tank of the 241-T Tank Farm in 1973. Five tanks are assumed to have leaked in the TY Farm. Many of the contaminants from those leaks still reside within the vadose zone within the T and TY Tank Farms. The Department of Energy's Office of River Protection seeks to minimize the movement of these contaminant plumes by placing interim barriers on the ground surface. Such barriers are expected to prevent infiltrating water from reaching the plumes and moving them further. The soil water regime is monitored to determine the effectiveness of the interim surface barriers. Soil-water content and water pressure are monitored using off-the-shelf equipment that can be installed by the hydraulic hammer technique. Four instrument nests were installed in the T Farm in fiscal year (FY) 2006 and FY2007; two nests were installed in the TY Farm in FY2010. Each instrument nest contains a neutron probe access tube, a capacitance probe, and four heat-dissipation units. A meteorological station has been installed at the north side of the fence of the T Farm. This document summarizes the monitoring methods, the instrument calibration and installation, and the vadose zone monitoring plan for interim barriers in T farm and TY Farm.

LONG-TERM COLLOID MOBILIZATION AND COLLOID-FACILITATED TRANSPORT OF RADIONUCLIDES IN A SEMI-ARID VADOSE ZONE

Energy Technology Data Exchange (ETDEWEB)

Markus Flury; James B. Harsh; Fred Zhang; Glendon W. Gee; Earl D. Mattson; Peter C. L

2012-08-01

The main purpose of this project was to improve the fundamental mechanistic understanding and quantification of long-term colloid mobilization and colloid-facilitated transport of radionuclides in the vadose zone, with special emphasis on the semi-arid Hanford site. While we focused some of the experiments on hydrogeological and geochemical conditions of the Hanford site, many of our results apply to colloid and colloid-facilitated transport in general. Specific objectives were (1) to determine the mechanisms of colloid mobilization and colloid-facilitated radionuclide transport in undisturbed Hanford sediments under unsaturated flow, (2) to quantify in situ colloid mobilization and colloid-facilitated radionuclidetransport from Hanford sediments under field conditions, and (3) to develop a field-scale conceptual and numerical model for colloid mobilization and transport at the Hanford vadose zone, and use that model to predict long-term colloid and colloid- facilitated radionuclide transport. To achieve these goals and objectives, we have used a combination of experimental, theoretical, and numerical methods at different spatial scales, ranging from microscopic investigationsof single particle attachment and detachment to larger-scale field experiments using outdoor lysimeters at the Hanford site. Microscopic and single particle investigations provided fundamental insight into mechanisms of colloid interactions with the air-water interface. We could show that a moving air water interface (such as a moving water front during infiltration and drainage) is very effective in removing and mobilizing particles from a stationary surface. We further demonstrated that it is particularly the advancing air-water interface which is mainly responsible for colloid mobilization. Forces acting on the colloids calculated from theory corroborated our experimental results, and confirm that the detachment forces (surface tension forces) during the advancing air-water interface

A COMPARISON BETWEEN ZERO-OFFSET AND VERTICAL RADAR PROFILING GPR TECHNIQUES WITH EMPHASIS ON PROBLEMATIC BOREHOLE EFFECTS

DEFF Research Database (Denmark)

Rossi, Matteo; Vignoli, Giulio; Cassiani, Giorgio

that the dielectric relative permittivity profiles recovered from ZOP and VRP first-break inversions are in strong disagreement, providing very different permittivity profiles. The analysis of synthetic radargrams shows the presence of an electromagnetic (EM) wave established by the joint presence of the air...... of the first recorded event depends on the ratio between the wave length in air and the finite dimension of the borehole. Once these arrivals in the simulated VRP radargrams are recognized, their contribution can be removed by picking the “direct”ù arrivals, that correspond to the waves that directly...... characterizations. Thus, VRP surveys in vadose zone must be accurately interpreted, as the electromagnetic waves may propagate via guided modes along the borehole. Neglecting this phenomenon might generate misleading estimations of geophysical properties and the subsequently translation in hydrological quantities...

Cave breakdown by vadose weathering.

Directory of Open Access Journals (Sweden)

Osborne R. Armstrong L.

2002-01-01

Full Text Available Vadose weathering is a significant mechanism for initiating breakdown in caves. Vadose weathering of ore bodies, mineral veins, palaeokarst deposits, non-carbonate keystones and impure, altered or fractured bedrock, which is intersected by caves, will frequently result in breakdown. Breakdown is an active, ongoing process. Breakdown occurs throughout the vadose zone, and is not restricted to large diameter passages, or to cave ceilings. The surfaces of disarticulated blocks are commonly coated, rather than having fresh broken faces, and blocks continue to disintegrate after separating from the bedrock. Not only gypsum, but also hydromagnesite and aragonite are responsible for crystal wedging. It is impossible to study or identify potential breakdown foci by surface surveys alone, in-cave observation and mapping are essential.

Colloid-Facilitated Transport of Radionuclides Through The Vadose Zone

International Nuclear Information System (INIS)

Markus Flury; James B. Harsh; John F. McCarthy' Peter C. Lichtner; John M. Zachara

2007-01-01

The main purpose of this project was to advance the basic scientific understanding of colloid and colloid-facilitated Cs transport of radionuclides in the vadose zone. We focused our research on the hydrological and geochemical conditions beneath the leaking waste tanks at the USDOE Hanford reservation. Specific objectives were (1) to determine the lability and thermodynamic stability of colloidal materials, which form after reacting Hanford sediments with simulated Hanford Tank Waste, (2) to characterize the interactions between colloidal particles and contaminants, i.e., Cs and Eu, (3) to determine the potential of Hanford sediments for in situ mobilization of colloids, (4) to evaluate colloid-facilitated radionuclide transport through sediments under unsaturated flow, (5) to implement colloid-facilitated contaminant transport mechanisms into a transport model, and (6) to improve conceptual characterization of colloid-contaminant-soil interactions and colloid-facilitated transport for clean-up procedures and long-term risk assessment

Results of 1999 Spectral Gamma-Ray and Neutron Moisture Monitoring of Boreholes at Specific Retention Facilities in the 200 East Area, Hanford Site

Energy Technology Data Exchange (ETDEWEB)

DG Horton; RR Randall

2000-01-18

Twenty-eight wells and boreholes in the 200 East Are% Hanford Site, Washington were monitored in 1999. The monitored facilities were past-practice liquid waste disposal facilities and consisted of six cribs and nineteen ''specific retention'' cribs and trenches. Monitoring consisted of spectral gamma-ray and neutron moisture logging. All data are included in Appendix B. The isotopes {sup 137}Cs, {sup 60}Co, {sup 235}U, {sup 238}U, and {sup 154}Eu were identified on spectral gamma logs from boreholes monitoring the PUREX specific retention facilities; the isotopes {sup 137}Cs, {sup 60}Co, {sup 125}Sb, and {sup 154}Eu were identified on the logs from boreholes at the BC Controlled Area cribs and trenches; and {sup 137}Cs, {sup 60}Co, and {sup 125}Sb were, identified on the logs from boreholes at the BX specific retention trenches. Three boreholes in the BC Controlled Area and one at the BX trenches had previous spectral gamma logs available for comparison with 1999 logs. Two of those logs showed that changes in the subsurface distribution of {sup 137}CS and/or {sup 60}Co had occurred since 1992. Although the changes are not great, they do point to continued movement of contaminants in the vadose zone. The logs obtained in 1999 create a larger baseline for comparison with future logs. Numerous historical gross gamma logs exist from most of the boreholes logged. Qualitative comparison of those logs with the 1999 logs show many substantial changes, most of which reflect the decay of deeper short-lived isotopes, such as {sup 106}Ru and {sup 125}Sb, and the much slower decay of shallower and longer-lived isotopes such as {sup 137}Cs. The radionuclides {sup 137}Cs and {sup 60}Co have moved in two boreholes since 1992. Given the amount of movement and the half-lives of the isotopes, it is expected that they will decay to insignificant amounts before reaching groundwater. However, gamma ray logging cannot detect many of the contaminants of interest such

Vadose Zone Monitoring of Dairy Green Water Lagoons using Soil Solution Samplers.

Energy Technology Data Exchange (ETDEWEB)

Brainard, James R.; Coplen, Amy K

2005-11-01

Over the last decade, dairy farms in New Mexico have become an important component to the economy of many rural ranching and farming communities. Dairy operations are water intensive and use groundwater that otherwise would be used for irrigation purposes. Most dairies reuse their process/green water three times and utilize lined lagoons for temporary storage of green water. Leakage of water from lagoons can pose a risk to groundwater quality. Groundwater resource protection infrastructures at dairies are regulated by the New Mexico Environment Department which currently relies on monitoring wells installed in the saturated zone for detecting leakage of waste water lagoon liners. Here we present a proposal to monitor the unsaturated zone beneath the lagoons with soil water solution samplers to provide early detection of leaking liners. Early detection of leaking liners along with rapid repair can minimize contamination of aquifers and reduce dairy liability for aquifer remediation. Additionally, acceptance of vadose zone monitoring as a NMED requirement over saturated zone monitoring would very likely significantly reduce dairy startup and expansion costs. Acknowledgment Funding for this project was provided by the Sandia National Laboratories Small Business Assistance Program

Linking river, floodplain, and vadose zone hydrology to improve restoration of a coastal river affected by saltwater intrusion.

Science.gov (United States)

Kaplan, D; Muñoz-Carpena, R; Wan, Y; Hedgepeth, M; Zheng, F; Roberts, R; Rossmanith, R

2010-01-01

Floodplain forests provide unique ecological structure and function, which are often degraded or lost when watershed hydrology is modified. Restoration of damaged ecosystems requires an understanding of surface water, groundwater, and vadose (unsaturated) zone hydrology in the floodplain. Soil moisture and porewater salinity are of particular importance for seed germination and seedling survival in systems affected by saltwater intrusion but are difficult to monitor and often overlooked. This study contributes to the understanding of floodplain hydrology in one of the last bald cypress [Taxodium distichum (L.) Rich.] floodplain swamps in southeast Florida. We investigated soil moisture and porewater salinity dynamics in the floodplain of the Loxahatchee River, where reduced freshwater flow has led to saltwater intrusion and a transition to salt-tolerant, mangrove-dominated communities. Twenty-four dielectric probes measuring soil moisture and porewater salinity every 30 min were installed along two transects-one in an upstream, freshwater location and one in a downstream tidal area. Complemented by surface water, groundwater, and meteorological data, these unique 4-yr datasets quantified the spatial variability and temporal dynamics of vadose zone hydrology. Results showed that soil moisture can be closely predicted based on river stage and topographic elevation (overall Nash-Sutcliffe coefficient of efficiency = 0.83). Porewater salinity rarely exceeded tolerance thresholds (0.3125 S m(-1)) for bald cypress upstream but did so in some downstream areas. This provided an explanation for observed vegetation changes that both surface water and groundwater salinity failed to explain. The results offer a methodological and analytical framework for floodplain monitoring in locations where restoration success depends on vadose zone hydrology and provide relationships for evaluating proposed restoration and management scenarios for the Loxahatchee River.

Determining flow, recharge, and vadose zone drainage in an unconfined aquifer from groundwater strontium isotope measurements, Pasco Basin, WA

International Nuclear Information System (INIS)

2004-01-01

Strontium isotope compositions (87Sr/86Sr) measured in groundwater samples from 273 wells in the Pasco Basin unconfined aquifer below the Hanford Site show large and systematic variations that provide constraints on groundwater recharge, weathering rates of the aquifer host rocks, communication between unconfined and deeper confined aquifers, and vadose zone-groundwater interaction. The impact of millions of cubic meters of wastewater discharged to the vadose zone (103-105 times higher than ambient drainage) shows up strikingly on maps of groundwater 87Sr/86Sr. Extensive access through the many groundwater monitoring wells at the site allows for an unprecedented opportunity to evaluate the strontium geochemistry of a major aquifer, hosted primarily in unconsolidated sediments, and relate it to both long term properties and recent disturbances. Groundwater 87Sr/86Sr increases systematically from 0.707 to 0.712 from west to east across the Hanford Site, in the general direction of groundwater flow, as a result of addition of Sr from the weathering of aquifer sediments and from diffuse drainage through the vadose zone. The lower 87Sr/86Sr groundwater reflects recharge waters that have acquired Sr from Columbia River Basalts. Based on a steady-state model of Sr reactive transport and drainage, there is an average natural drainage flux of 0-1.4 mm/yr near the western margin of the Hanford Site, and ambient drainage may be up to 30 mm/yr in the center of the site assuming an average bulk rock weathering rate of 10-7.5 g/g/yr

Characterization plan for the immobilized low-activity waste borehole

International Nuclear Information System (INIS)

Reidel, S.P.; Reynolds, K.D.

1998-03-01

The US Department of Energy's (DOE's) Hanford Site has the most diverse and largest amounts of radioactive tank waste in the US. High-level radioactive waste has been stored at Hanford in large underground tanks since 1944. Approximately 209,000 m 3 (54 Mgal) of waste are currently stored in 177 tanks. Vitrification and onsite disposal of low activity tank waste (LAW) are embodied in the strategy described in the Tri-Party Agreement. The tank waste is to be retrieved, separated into low- and high-level fractions, and then immobilized by private vendors. The DOE will receive the vitrified waste from private vendors and dispose of the low-activity fraction in the Hanford Site 200 East Area. The Immobilized Low-Activity Waste Disposal Complex (ILAWDC) is part of the disposal complex. This report is a plan to drill the first characterization borehole and collect data at the ILAWDC. This plan updates and revises the deep borehole portion of the characterization plan for the ILAWDC by Reidel and others (1995). It describes data collection activities for determining the physical and chemical properties of the vadose zone and the saturated zone at and in the immediate vicinity of the proposed ILAWDC. These properties then will be used to develop a conceptual geohydrologic model of the ILAWDC site in support of the Hanford ILAW Performance Assessment

Fracture Modes and Identification of Fault Zones in Wenchuan Earthquake Fault Scientific Drilling Boreholes

Science.gov (United States)

Deng, C.; Pan, H.; Zhao, P.; Qin, R.; Peng, L.

2017-12-01

After suffering from the disaster of Wenchuan earthquake on May 12th, 2008, scientists are eager to figure out the structure of formation, the geodynamic processes of faults and the mechanism of earthquake in Wenchuan by drilling five holes into the Yingxiu-Beichuan fault zone and Anxian-Guanxian fault zone. Fractures identification and in-situ stress determination can provide abundant information for formation evaluation and earthquake study. This study describe all the fracture modes in the five boreholes on the basis of cores and image logs, and summarize the response characteristics of fractures in conventional logs. The results indicate that the WFSD boreholes encounter enormous fractures, including natural fractures and induced fractures, and high dip-angle conductive fractures are the most common fractures. The maximum horizontal stress trends along the borehole are deduced as NWW-SEE according to orientations of borehole breakouts and drilling-induced fractures, which is nearly parallel to the strikes of the younger natural fracture sets. Minor positive deviations of AC (acoustic log) and negative deviation of DEN (density log) demonstrate their responses to fracture, followed by CNL (neutron log), resistivity logs and GR (gamma ray log) at different extent of intensity. Besides, considering the fact that the reliable methods for identifying fracture zone, like seismic, core recovery and image logs, can often be hampered by their high cost and limited application, this study propose a method by using conventional logs, which are low-cost and available in even old wells. We employ wavelet decomposition to extract the high frequency information of conventional logs and reconstruction a new log in special format of enhance fracture responses and eliminate nonfracture influence. Results reveal that the new log shows obvious deviations in fault zones, which confirm the potential of conventional logs in fracture zone identification.

Surface and subsurface continuous gravimetric monitoring of groundwater recharge processes through the karst vadose zone at Rochefort Cave (Belgium)

Science.gov (United States)

Watlet, A.; Van Camp, M. J.; Francis, O.; Poulain, A.; Hallet, V.; Triantafyllou, A.; Delforge, D.; Quinif, Y.; Van Ruymbeke, M.; Kaufmann, O.

2017-12-01

Ground-based gravimetry is a non-invasive and integrated tool to characterize hydrological processes in complex environments such as karsts or volcanoes. A problem in ground-based gravity measurements however concerns the lack of sensitivity in the first meters below the topographical surface, added to limited infiltration below the gravimeter building (umbrella effect). Such limitations disappear when measuring underground. Coupling surface and subsurface gravity measurements therefore allow isolating hydrological signals occurring in the zone between the two gravimeters. We present a coupled surface/subsurface continuous gravimetric monitoring of 2 years at the Rochefort Cave Laboratory (Belgium). The gravity record includes surface measurements of a GWR superconducting gravimeter and subsurface measurements of a Micro-g LaCoste gPhone gravimeter, installed in a cave 35 m below the surface station. The recharge of karstic aquifers is extremely complex to model, mostly because karst hydrological systems are composed of strongly heterogeneous flows. Most of the problem comes from the inadequacy of conventional measuring tools to correctly sample such heterogeneous media, and particularly the existence of a duality of flow types infiltrating the vadose zone: from rapid flows via open conduits to slow seepage through porous matrix. Using the surface/subsurface gravity difference, we were able to identify a significant seasonal groundwater recharge within the karst vadose zone. Seasonal or perennial perched reservoirs have already been proven to exist in several karst areas due to the heterogeneity of the porosity and permeability gradient in karstified carbonated rocks. Our gravimetric experiment allows assessing more precisely the recharge processes of such reservoirs. The gravity variations were also compared with surface and in-cave hydrogeological monitoring (i.e. soil moisture, in-cave percolating water discharges, water levels of the saturated zone). Combined

Hydrologic properties of the vadose zone at B292

International Nuclear Information System (INIS)

Shinn, J.; Mallon, B.; Martins, S.

1992-09-01

A formula for the unsaturated hydraulic conductivity was derived for the vadose zone down to the 45-foot depth by analysis of data from 5 wells near B292. The formula gives the median hydraulic conductivity as a function of depth and soil-water content, and was obtained by parameterization of saturated hydraulic conductivity and the water-retention characteristics to the median particle diameter of soil samples. It was noted that the variation of median particle diameter among soil samples at the same depth, taken from 5 wells in close proximity to B292, would have a great effect on saturated hydraulic conductivity. The coefficient of variation of median particle diameter was estimated to be 1.23 at any depth, based on apparent log-normal frequency distribution. The coefficient of variation of measured and predicted saturated hydraulic conductivity was estimated to be 7.9; large values are found in the literature as well

An Exact Solution for the Assessment of Nonequilibrium Sorption of Radionuclides in the Vadose Zone

International Nuclear Information System (INIS)

Drake, R. L.; Chen, J-S.

2002-01-01

In a report on model evaluation, the authors ran the HYDRUS Code, among other transport codes, to evaluate the impacts of nonequilibrium sorption sites on the time-evolution of 99Tc and 90Sr through the vadose zone. Since our evaluation was based on a rather low, annual recharge rate, many of the numerical results derived from HYDRUS indicated that the nonequilibrium sorption sites, in essence, acted as equilibrium sorption sites. To help explain these results, we considered a ''stripped-down'' version of the HYDRUS system. This ''stripped-down'' version possesses two dependent variables, one for the radionuclides in solution and the other for the radionuclides adsorbed to the nonequilibrium sites; and it possesses constant physical parameters. The resultant governing equation for the radionuclides in solution is a linear, advection-dispersion-reaction (i.e., radioactive decay) partial differential equation containing a history integral term accounting for the nonequilibrium sorption sites. It is this ''stripped-down'' version, which is the subject of this paper. We found an exact solution to this new version of the model. The exact solution is given in terms of a single definite integral of terms involving elementary functions of the independent variables and the system parameters. This integral possesses adequate convergence properties and is easy to evaluate, both in a quantitative matter and in a qualitative manner. The parameters that are considered in the system are as follows: the radionuclide's equilibrium partition coefficient between water and soil, the bulk density of the soil, the fractions of equilibrium/nonequilibrium sorption sites, the volumetric water content, the first order equilibrium adsorption rate constant, the first order radioactive decay rate constant, the liquid water soil tortuosity factor, the molecular diffusion coefficient in water, the longitudinal dispersivity factor, and the Darcian fluid flux density. In addition, the system

Coupled effects of solution chemistry and hydrodynamics on the mobility and transport of quantum dot nanomaterials in the Vadose Zone

Science.gov (United States)

To investigate the coupled effects of solution chemistry and vadose zone processes on the mobility of quantum dot (QD) nanoparticles, laboratory scale transport experiments were performed. The complex coupled effects of ionic strength, size of QD aggregates, surface tension, contact angle, infiltrat...

Managed aquifer recharge of treated wastewater: water quality changes resulting from infiltration through the vadose zone.

Science.gov (United States)

Bekele, Elise; Toze, Simon; Patterson, Bradley; Higginson, Simon

2011-11-01

Secondary treated wastewater was infiltrated through a 9 m-thick calcareous vadose zone during a 39 month managed aquifer recharge (MAR) field trial to determine potential improvements in the recycled water quality. The water quality improvements of the recycled water were based on changes in the chemistry and microbiology of (i) the recycled water prior to infiltration relative to (ii) groundwater immediately down-gradient from the infiltration gallery. Changes in the average concentrations of several constituents in the recycled water were identified with reductions of 30% for phosphorous, 66% for fluoride, 62% for iron and 51% for total organic carbon when the secondary treated wastewater was infiltrated at an applied rate of 17.5 L per minute with a residence time of approximately four days in the vadose zone and less than two days in the aquifer. Reductions were also noted for oxazepam and temazepam among the pharmaceuticals tested and for a range of microbial pathogens, but reductions were harder to quantify as their magnitudes varied over time. Total nitrogen and carbamazepine persisted in groundwater down-gradient from the infiltration galleries. Infiltration does potentially offer a range of water quality improvements over direct injection to the water table without passage through the unsaturated zone; however, additional treatment options for the non-potable water may still need to be considered, depending on the receiving environment or the end use of the recovered water. Crown Copyright © 2011. Published by Elsevier Ltd. All rights reserved.

Bioventing - a new twist on soil vapor remediation of the vadose zone and shallow ground water

International Nuclear Information System (INIS)

Yancheski, T.B.; McFarland, M.A.

1992-01-01

Bioventing, which is a combination of soil vapor remediation and bioremediation techniques, may be an innovative, cost-effective, and efficient remedial technology for addressing petroleum contamination in the vadose zone and shallow ground water. The objective of bioventing is to mobilize petroleum compounds from the soil and ground water into soil vapor using soil vapor extraction and injection technology, and to promote the migration of the soil vapor upward to the turf root zone for degradation by active near-surface microbiological activity. Promoting and maintaining optimum microbiological activity in the turf root rhizosphere is a key component to the bioventing technique. Preliminary ongoing USEPA bioventing pilot studies (Kampbell, 1991) have indicated that this technique is a promising remediation technology, although feasibility studies are not yet complete. However, based on the preliminary data, it appears that proper bioventing design and implementation will result in substantial reductions of petroleum compounds in the capillary zone and shallow ground water, complete degradation of petroleum compounds in the turf root zone, and no surface emissions. A bioventing system was installed at a site in southern Delaware with multiple leaking underground storage tanks in early 1992 to remediate vadose zone and shallow ground-water contaminated by petroleum compounds. The system consists of a series of soil vapor extraction and soil vapor/atmospheric air injection points placed in various contamination areas and a central core remediation area (a large grassy plot). This system was chosen for this site because it was least costly to implement and operate as compared to other remedial alternatives (soil vapor extraction with carbon or catalytic oxidation of off-gas treatment, insitu bioremediation, etc.), and results in the generation of no additional wastes

The vadose zone as a geoindicator of environmental change and groundwater quality in water-scarce areas

Science.gov (United States)

Edmunds, W. M.; Baba Goni, I.; Gaye, C. B.; Jin, L.

2013-12-01

Inert and reactive tracers in moisture profiles provide considerable potential for the vadose zone to be used as an indicator of rapid environmental change. This indicator is particularly applicable in areas of water stress where long term (decade to century) scale records may be found in deep unsaturated zones in low rainfall areas and provide insights into recent recharge, climate variation and water-rock interactions which generate groundwater quality. Unsaturated zone Cl records obtained by elutriation of moisture are used widely for estimating recharge and water balance studies; isotope profiles (3H, δ2H, δ18O) from total water extraction procedures are used for investigation of residence times and hydrological processes. Apart from water taken using lysimeters, little work has been conducted directly on the geochemistry of pore fluids. This is mainly due to the difficulties of extraction of moisture from unsaturated material with low water contents (typically 2-6 wt%) and since dilution methods can create artifacts. Using immiscible liquid displacement techniques it is now possible to directly investigate the geochemistry of moisture from unsaturated zone materials. Profiles up to 35m from Quaternary sediments from dryland areas of the African Sahel (Nigeria, Senegal) as well as Inner Mongolia, China are used to illustrate the breadth of information obtainable from vadose zone profiles. Using pH, major and trace elements and comparing with isotopic data, a better understanding is gained of timescales of water movement, aquifer recharge, environmental records and climate history as well as water-rock interaction and contaminant behaviour. The usefulness of tritium as residence time indicator has now expired following cessation of atmospheric thermonuclear testing and through radioactive decay. Providing the rainfall Cl, moisture contents and bulk densities of the sediments are known, then Cl accumulation can be substituted to estimate timescales. Profiles

Three-dimensional modeling of nitrate-N transport in vadose zone: Roles of soil heterogeneity and groundwater flux

Science.gov (United States)

Akbariyeh, Simin; Bartelt-Hunt, Shannon; Snow, Daniel; Li, Xu; Tang, Zhenghong; Li, Yusong

2018-04-01

Contamination of groundwater from nitrogen fertilizers in agricultural lands is an important environmental and water quality management issue. It is well recognized that in agriculturally intensive areas, fertilizers and pesticides may leach through the vadose zone and eventually reach groundwater. While numerical models are commonly used to simulate fate and transport of agricultural contaminants, few models have considered a controlled field work to investigate the influence of soil heterogeneity and groundwater flow on nitrate-N distribution in both root zone and deep vadose zone. In this work, a numerical model was developed to simulate nitrate-N transport and transformation beneath a center pivot-irrigated corn field on Nebraska Management System Evaluation area over a three-year period. The model was based on a realistic three-dimensional sediment lithology, as well as carefully controlled irrigation and fertilizer application plans. In parallel, a homogeneous soil domain, containing the major sediment type of the site (i.e. sandy loam), was developed to conduct the same water flow and nitrate-N leaching simulations. Simulated nitrate-N concentrations were compared with the monitored nitrate-N concentrations in 10 multi-level sampling wells over a three-year period. Although soil heterogeneity was mainly observed from top soil to 3 m below the surface, heterogeneity controlled the spatial distribution of nitrate-N concentration. Soil heterogeneity, however, has minimal impact on the total mass of nitrate-N in the domain. In the deeper saturated zone, short-term variations of nitrate-N concentration correlated with the groundwater level fluctuations.

3D vadose zone modeling using geostatistical inferences

International Nuclear Information System (INIS)

Knutson, C.F.; Lee, C.B.

1991-01-01

In developing a 3D model of the 600 ft thick interbedded basalt and sediment complex that constitutes the vadose zone at the Radioactive Waste Management Complex (RWMC) at the Idaho National Engineering Laboratory (INEL) geostatistical data were captured for 12--15 parameters (e.g. permeability, porosity, saturation, etc. and flow height, flow width, flow internal zonation, etc.). This two scale data set was generated from studies of subsurface core and geophysical log suites at RWMC and from surface outcrop exposures located at the Box Canyon of the Big Lost River and from Hell's Half Acre lava field all located in the general RWMC area. Based on these currently available data, it is possible to build a 3D stochastic model that utilizes: cumulative distribution functions obtained from the geostatistical data; backstripping and rebuilding of stratigraphic units; an ''expert'' system that incorporates rules based on expert geologic analysis and experimentally derived geostatistics for providing: (a) a structural and isopach map of each layer, (b) a realization of the flow geometry of each basalt flow unit, and (c) a realization of the internal flow parameters (eg permeability, porosity, and saturation) for each flow. 10 refs., 4 figs., 1 tab

Vadose Zone Hydrogeology Data Package for Hanford Assessments

Energy Technology Data Exchange (ETDEWEB)

Last, George V.; Freeman, Eugene J.; Cantrell, Kirk J.; Fayer, Michael J.; Gee, Glendon W.; Nichols, William E.; Bjornstad, Bruce N.; Horton, Duane G.

2006-06-01

This data package documents the technical basis for selecting physical and geochemical parameters and input values that will be used in vadose zone modeling for Hanford assessments. This work was originally conducted as part of the Characterization of Systems Task of the Groundwater Remediation Project managed by Fluor Hanford, Inc., Richland, Washington, and revised as part of the Characterization of Systems Project managed by the Pacific Northwest National Laboratory (PNNL) for the U.S. Department of Energy, Richland Operations Office (DOE-RL). This data package describes the geologic framework, the physical, hydrologic, and contaminant transport properties of the geologic materials, and deep drainage (i.e., recharge) estimates, and builds on the general framework developed for the initial assessment conducted using the System Assessment Capability (SAC) (Bryce et al. 2002). The general approach for this work was to update and provide incremental improvements over the previous SAC data package completed in 2001. As with the previous SAC data package, much of the data and interpreted information were extracted from existing documents and databases. Every attempt was made to provide traceability to the original source(s) of the data or interpretations.

Description of Work for Drilling at the 183-DR Site in Support of the In Situ Gaseous Reduction Test

Energy Technology Data Exchange (ETDEWEB)

Thornton, Edward C.; Olsen, Khris B.; Schalla, Ronald

2000-06-26

In Situ Gaseous Reduction is a technology currently being developed by DOE for the remediation of soil waste sites contaminated with hexavalent chromium. Prior work suggests that a candidate for application of this approach is the 183-DR site at Hanford. However, deep vadose zone drilling is needed to verify the presence of a hexavalent chromium source and to determine the concentration levels and spatial distribution of contamination. This document presents the requirements associated with drilling one to two vadose zone boreholes at the 183-DR site to obtain this information. If hexavalent chromium is determined to be present at levels of at least 10 ppm in the vadose zone in one of the initial boreholes, this hole will be completed for gas injection and six additional gas extraction boreholes will be drilled and completed. This network will be used as a flowcell for performing a gas treatment test at the site.

H51E-1535: Biogeochemical factors influencing the transport and fate of colloids and colloid-associated contaminants in the vadose zone

Science.gov (United States)

The vadose zone exhibits large spatial and temporal variability in many physical, chemical, and biological factors that strongly influence the transport and fate of colloids (e.g., microbes, nanoparticles, clays, and dissolved organic matter) and colloid-associated contaminants (e.g., heavy metals, ...

Characterization of contaminant transport by gravity, capillarity and barometric pumping in heterogeneous vadose regimes. 1998 annual progress report

International Nuclear Information System (INIS)

Carrigan, C.R.; Hudson, G.B.

1998-01-01

'The intent of this research program is to obtain an improved understanding of vadose zone transport processes and to develop field and modeling techniques required to characterize contaminant transport in the unsaturated zone at DOE sites. For surface spills and near-surface leaks of chemicals, the vadose zone may well become a long-term source of contamination for the underlying water table. Transport of contaminants can occur in both the liquid and gas phases of the unsaturated zone. This transport occurs naturally as a result of diffusion, buoyancy forces (gravity), capillarity and barometric pressure variations. In some cases transport can be enhanced by anisotropies present in hydrologic regimes. This is particularly true for gas-phase transport which may be subject to vertical pumping resulting from atmospheric pressure changes. For liquid-phase flows, heterogeneity may enhance the downward transport of contaminants to the water table depending on soil properties and the scale of the surface spill or near-surface leak. Characterization techniques based upon the dynamics of transport processes are likely to yield a better understanding of the potential for contaminant transport at a specific site than methods depending solely on hydrologic properties derived from a borehole. Such dynamic-characterization techniques can be useful for evaluating sites where contamination presently exists as well as for providing an objective basis to evaluate the efficacy of proposed as well as implemented clean-up technologies. The real-time monitoring of processes that may occur during clean-up of tank waste and the mobility of contaminants beneath the Hanford storage tanks during sluicing operations is one example of how techniques developed in this effort can be applied to current remediation problems. In the future, such dynamic-characterization methods might also be used as part of the site-characterization process for determining suitable locations of new DOE facilities

Bioventing in the subarctic: Field scale implementation of soil heating to allow in situ vadose zone biodegradation throughout the year

International Nuclear Information System (INIS)

Oram, D.E.; Winters, A.T.; Winsor, T.R.

1994-01-01

Bioventing is a technique of in situ bioremediation of contaminants in unsaturated zone soils that has advantages over other technologies such as soil vapor extraction. At locations where off-gas treatment would be required, bioventing can be a more cost-effective method of remediation. Using bioventing to remediate petroleum hydrocarbons in the vadose zone soils in extremely cold climates may be augmented by heating the subsurface soils. The US Air Force has conducted a bioventing feasibility study at Eielson Air Force Base since 1991. The feasibility study evaluated different methods of heating soils to maintain biodegradation rates through the winter. Results from this study were used to optimize the design of a full-scale bioventing system that incorporated a soil heating system. The system installed consists of the typical components of a bioventing system including an air injection blower, a system to distribute air in the vadose zone, and a monitoring system. To maintain biodegradation at a constant rate throughout the year, soil heating and temperature monitoring systems were also installed. Results to date indicate that summer soil temperatures and biodegradation of hydrocarbons have been maintained through the winter

Immobilization of Radionuclides in the Hanford Vadose Zone by Incorporation in Solid Phases

International Nuclear Information System (INIS)

Brown, Gordon E. Jr.; Catalano, Jeffrey G.; Warner, Jeffrey A.; Samual Shaw; Daniel Grolimund

2005-01-01

The Department of Energy's Hanford Nuclear Site located in Washington State has accumulated over 2 million curies of radioactive waste from activities related to the production of plutonium (Ahearne, 1997). Sixty-seven of the single-shelled tanks located at the site are thought to have leaked, allowing between 2 and 4 million liters of waste fluids into the underlying vadose zone. The chemical processes employed at the Hanford Site to extract plutonium, as well as the need to minimize corrosion of the high-carbon steel storage tanks, resulted in uncharacterized hyperalkaline waste streams rich in radionuclides as well as other species including significant amounts of sodium and aluminum

Chaotic-Dynamical Conceptual Model to Describe Fluid Flow and Contaminant Transport in a Fractured Vadose Zone

International Nuclear Information System (INIS)

Faybishenko, Boris; Doughty, Christine; Geller, Jil T.

1999-01-01

DOE faces the remediation of numerous contaminated sites, such as those at Hanford, INEEL, LLNL, and LBNL, where organic and/or radioactive wastes were intentionally or accidentally released to the vadose zone from surface spills, underground tanks, cribs, shallow ponds, and deep wells. Migration of these contaminants through the vadose zone has led to the contamination of (or threatens to contaminate) underlying groundwater. A key issue in choosing a corrective action plan to clean up contaminated sites is the determination of the location, total mass, mobility and travel time to receptors for contaminants moving in the vadose zone. These problems are difficult to solve in a technically defensible and accurate manner because contaminants travel downward intermittently, through narrow pathways, driven by variations in environmental conditions. These preferential flow pathways can be difficult to find and predict. The primary objective of this project is to determine if and when dynamical chaos theory can be used to investigate infiltration of fluid and contaminant transport in heterogeneous soils and fractured rocks. The objective of this project is being achieved through the following activities: Development of multi scale conceptual models and mathematical and numerical algorithms for flow and transport, which incorporate both (a) the spatial variability of heterogeneous porous and fractured media and (b) the temporal dynamics of flow and transport; Development of appropriate experimental field and laboratory techniques needed to detect diagnostic parameters for chaotic behavior of flow; Evaluation of chaotic behavior of flow in laboratory and field experiments using methods from non-linear dynamics; Evaluation of the impact these dynamics may have on contaminant transport through heterogeneous fractured rocks and soils and remediation efforts. This approach is based on the consideration of multi scale spatial heterogeneity and flow phenomena that are affected by

Water movement and solute transport in deep vadose zone under four irrigated agricultural land-use types in the North China Plain

Science.gov (United States)

Min, Leilei; Shen, Yanjun; Pei, Hongwei; Wang, Ping

2018-04-01

Groundwater-fed agriculture has caused water table declines and groundwater quality degradation in the North China Plain. Based on sediment sampling in deep vadose zone (with a maximum depth of 11.0 m), groundwater recharge, seepage velocity, solute inventory and transport under four typical irrigated agricultural land-use types (winter wheat and summer maize, WM; pear orchards, PO; outdoor vegetables, VE; and cotton, CO) were investigated in this study. The results reveal that there are many solutes stored in the vadose zone. Nitrate storage per unit depth in the vadose zone is highest under PO (1703 kg/ha), followed by VE (970 kg/ha), WM (736 kg/ha) and CO (727 kg/ha). However, the amount of annual leached nitrate under the four land-use types results in a different order (VE, 404 kg/ha; WM, 108 kg/ha; PO, 23 kg/ha; CO, 13 kg/ha). The estimated average recharge rates are 180 mm/yr for WM, 27 mm/yr for CO, 320 mm/yr for VE and 49 mm/yr for PO. The seepage velocity under VE (2.22 m/yr) exceeds the values under the other three land-use types (WM, 0.85 m/yr; PO, 0.49 m/yr; CO, 0.09 m/yr). The highest seepage velocity under VE caused significant nitrate contamination in groundwater, whereas the other two land-use types (WM and PO) had no direct influence on groundwater quality. The results of this work could be used for groundwater resources management.

Description of work vadose drilling at the 1301-N and 1325-N facilities, 100-NR-1 operable unit

International Nuclear Information System (INIS)

1994-08-01

This description of work (DOW) details the field activities associated with the sampling of the vadose zone soils beneath the 1301-N and 1325-N cribs and trenches and will serve as a field guide for those performing the work. These activities are undertaken pursuant to the Hanford Federal Facility Agreement and Consent Order (Ecology et al., 1994a) Milestone M-16-94-01H-Tl and the June 30, 1994 Milestone Change Request M-16-94-02 (Ecology et al., 1994b). Three vadose zone borings, 1301-N-1, 1301-N-2, and 1325-N-1, will be constructed to investigate the vertical and horizontal distribution of radionuclide contamination in sediments beneath the cribs and trenches. The boreholes are also intended to intersect subsurface areas that may have been contaminated by dangerous wastes, i.e., metals, in effluent disposed during past operation of the facilities. This limited field investigation will provide data for the evaluation of remedial alternatives. Data from the investigation are expected to confirm that the cribs and trenches are high priority sites in the 100-NR-1 operable unit. Data, from the investigation will be used to evaluate alternatives for closure of the 1301-N and 1325-N sites. The contaminants of potential concern (COPCs) for the 1301-N/1325-N limited field investigation are presented in Table 1

Influence of colloids on the attenuation and transport of phosphorus in alluvial gravel aquifer and vadose zone media.

Science.gov (United States)

Pang, Liping; Lafogler, Mark; Knorr, Bastian; McGill, Erin; Saunders, Darren; Baumann, Thomas; Abraham, Phillip; Close, Murray

2016-04-15

Phosphorous (P) leaching (e.g., from effluents, fertilizers) and transport in highly permeable subsurface media can be an important pathway that contributes to eutrophication of receiving surface waters as groundwater recharges the base-flow of surface waters. Here we investigated attenuation and transport of orthophosphate-P in gravel aquifer and vadose zone media in the presence and absence of model colloids (Escherichia coli, kaolinite, goethite). Experiments were conducted using repacked aquifer media in a large column (2m long, 0.19m in diameter) and intact cores (0.4m long, 0.24m in diameter) of vadose zone media under typical field flow rates. In the absence of the model colloids, P was readily traveled through the aquifer media with little attenuation (up to 100% recovery) and retardation, and P adsorption was highly reversible. Conversely, addition of the model colloids generally resulted in reduced P concentration and mass recovery (down to 28% recovery), and increased retardation and adsorption irreversibility in both aquifer and vadose zone media. The degree of colloid-assisted P attenuation was most significant in the presence of fine material and Fe-containing colloids at low flow rate but was least significant in the presence of coarse gravels and E. coli at high flow rate. Based on the experimental results, setback distances of 49-53m were estimated to allow a reduction of P concentrations in groundwater to acceptable levels in the receiving water. These estimates were consistent with field observations in the same aquifer media. Colloid-assisted P attenuation can be utilized to develop mitigation strategies to better manage effluent applications in gravelly soils. To efficiently retain P within soil matrix and reduce P leaching to groundwater, it is recommended to select soils that are rich in iron oxides, to periodically disturb soil preferential flow paths by tillage, and to apply a low irrigation rate. Copyright © 2016 Elsevier B.V. All rights

E-Area Low-Level Waste Facility Vadose Zone Model: Confirmation of Water Mass Balance for Subsidence Scenarios

Energy Technology Data Exchange (ETDEWEB)

Dyer, J. A. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2017-11-30

In preparation for the next revision of the E-Area Low-Level Waste Facility (LLWF) Performance Assessment (PA), a mass balance model was developed in Microsoft Excel to confirm correct implementation of intact- and subsided-area infiltration profiles for the proposed closure cap in the PORFLOW vadose-zone model. The infiltration profiles are based on the results of Hydrologic Evaluation of Landfill Performance (HELP) model simulations for both intact and subsided cases.

Which key properties controls the preferential transport in the vadose zone under transient hydrological conditions

Science.gov (United States)

Groh, J.; Vanderborght, J.; Puetz, T.; Gerke, H. H.; Rupp, H.; Wollschlaeger, U.; Stumpp, C.; Priesack, E.; Vereecken, H.

2015-12-01

Understanding water flow and solute transport in the unsaturated zone is of great importance for an appropriate land use management strategy. The quantification and prediction of water and solute fluxes through the vadose zone can help to improve management practices in order to limit potential risk on our fresh water resources. Water related solute transport and residence time is strongly affected by preferential flow paths in the soil. Water flow in soils depends on soil properties and site factors (climate or experiment conditions, land use) and are therefore important factors to understand preferential solute transport in the unsaturated zone. However our understanding and knowledge of which on-site properties or conditions define and enhance preferential flow and transport is still poor and mostly limited onto laboratory experimental conditions (small column length and steady state boundary conditions). Within the TERENO SOILCan lysimeter network, which was designed to study the effects of climate change on soil functions, a bromide tracer was applied on 62 lysimeter at eight different test sites between Dec. 2013 and Jan. 2014. The TERENO SOILCan infrastructure offers the unique possibility to study the occurrence of preferential flow and transport of various soil types under different natural transient hydrological conditions and land use (crop, bare and grassland) at eight TERENO SOILCan observatories. Working with lysimeter replicates at each observatory allows defining the spatial variability of preferential transport and flow. Additionally lysimeters in the network were transferred within and between observatories in order to subject them to different rainfall and temperature regimes and enable us to relate the soil type susceptibility of preferential flow and transport not only to site specific physical and land use properties, but also to different transient boundary conditions. Comparison and statistical analysis between preferential flow indicators 5

Modeling non-steady state radioisotope transport in the vadose zone--A case study using uranium isotopes at Pena Blanca, Mexico

International Nuclear Information System (INIS)

Ku, T.L.; Luo, S.; Goldstein, S.J.; Murrell, M.T.; Chu, W.L.; Dobson, P.F.

2009-01-01

Current models using U- and Th-series disequilibria to study radioisotope transport in groundwater systems mostly consider a steady-state situation. These models have limited applicability to the vadose zone (UZ) where the concentration and migratory behavior of radioisotopes in fluid are often transitory. We present here, as a first attempt of its kind, a model simulating the non-steady state, intermittent fluid transport in vadose layers. It provides quantitative constraints on in-situ migration of dissolved and colloidal radioisotopes in terms of retardation factor and rock-water interaction (or water transit) time. For uranium, the simulation predicts that intermittent flushing in the UZ leads to a linear relationship between reciprocal U concentration and 234 U/ 238 U ratio in percolating waters, with the intercept and slope bearing information on the rates of dissolution and α-recoil of U isotopes, respectively. The general validity of the model appears to be borne out by the measurement of uranium isotopes in UZ waters collected at various times over a period during 1995-2006 from a site in the Pena Blanca mining district, Mexico, where the Nopal I uranium deposit is located. Enhanced 234 U/ 238 U ratios in vadose-zone waters resulting from lengthened non-flushing time as prescribed by the model provide an interpretative basis for using 234 U/ 238 U in cave calcites to reconstruct the regional changes in hydrology and climate. We also provide a theoretical account of the model's potential applications using radium isotopes.

Vadose zone monitoring at the radioactive waste management complex, Idaho National Engineering Laboratory

International Nuclear Information System (INIS)

McElroy, D.L.; Hubbell, J.M.

1989-01-01

A network of vadose zone instruments was installed in surficial sediments and sedimentary interbeds beneath the Radioactive Waste Management Complex (RWMC) of the Idaho National Engineering Laboratory. The network of instruments monitor moisture movement in a heterogeneous geologic system comprised of sediments which overlie and are intercalated with basalt flows. The general range of matric potentials in the surficial sediments (0 to 9.1 m) was from saturation to -3 bars. The basalt layer beneath the surficial sediments impedes downward water movement. The general range of matric potentials in the 9-, 34- and 73-m interbeds was from -0.3 to 1.7 bars. Preliminary results indicated downward moisture movement through the interbeds. 8 refs., 9 figs., 1 tab

Borehole logging in uranium exploration

International Nuclear Information System (INIS)

Kulkarni, N.H.

1992-01-01

The ultimate objective of exploration by drilling as far as Atomic Minerals Division is concerned is to locate the ore zone in the subsurface, draw samples and analyze them for their metal content. The presence of the ore zone is also indicated by gamma-ray logging of the borehole. A gamma-ray detector is lowered in the borehole and precise depth and grade of the ore zone is established. This helps the geologist in correlating the ore horizon with the surface outcrop or the ore zone intercepted in adjoining boreholes and in deciding about further drilling and location of boreholes. Most commonly, total gamma measurements are made although some units capable of measuring the gamma-ray spectrum are also in use. It is possible to know if the mineralization is due to uranium without waiting for the laboratory results. The present write up gives a brief account of the principles, equipment and methods of borehole gamma-ray logging including density and self-potential logging. (author). 8 refs., 5 figs

Three dimensional numerical modeling for investigation of fracture zone filled with water by borehole radar; Borehole radar ni yoru gansui hasaitai kenshutsu no sanjigen suchi modeling

Energy Technology Data Exchange (ETDEWEB)

Sanada, Y; Watanabe, T; Ashida, Y [Kyoto University, Kyoto (Japan); Hasegawa, K; Yabuuchi, S [Power Reactor and Nuclear Fuel Development Corp., Tokyo (Japan)

1997-05-27

Water bearing fracture zones existing in rock mass largely influence the underground water flow and dynamic property of rock mass. The detailed survey of the location and size of water bearing fracture zones is an important task in the fields such as civil engineering, environment and disaster prevention. Electromagnetic waves of high frequency zones can be grasped as a wave phenomenon, and the record obtained in the actual measurement is wave forms of time series. In the exploration using borehole radar, this water bearing fracture zone becomes the reflection surface, and also becomes a factor of damping in the transmitted wave. By examining changes which these give to the observed wave forms, therefore, water bearing fracture zones can be detected. This study made three dimensional numerical modeling using the time domain finite difference method, and obtained the same output as the observed wave form obtained using borehole radar. By using this program and changing each of the parameters such as frequency and resistivity in the homogeneous medium, changes of the wave forms were observed. Further, examples were shown of modeling of detection of water bearing fracture zones. 5 refs., 16 figs., 1 tab.

Plutonium Particle Migration in the Shallow Vadose Zone: The Nevada Test Site as an Analog Site

Science.gov (United States)

Hunt, J. R.; Smith, D. K.

2004-12-01

The upper meter of the vadose zone in desert environments is the horizon where wastes have been released and human exposure is determined through dermal, inhalation, and food uptake pathways. This region is also characterized by numerous coupled processes that determine contaminant transport, including precipitation infiltration, evapotranspiration, daily and annual temperature cycling, dust resuspension, animal burrowing, and geochemical weathering reactions. While there is considerable interest in colloidal transport of minerals, pathogenic organisms, and contaminants in the vadose zone, there are limited field sites where the actual occurrence of contaminant migration can be quantified over the appropriate spatial and temporal scales of interest. At the US Department of Energy Nevada Test Site, there have been numerous releases of radionuclides since the 1950's that have become field-scale tracer tests. One series of tests was the four safety shots conducted in an alluvial valley of Area 11 in the 1950's. These experiments tested the ability of nuclear materials to survive chemical explosions without initiating fission reactions. Four above-ground tests were conducted and they released plutonium and uranium on the desert valley floor with only one of the tests undergoing some fission. Shortly after the tests, the sites were surveyed for radionuclide distribution on the land surface using aerial surveys and with depth. Additional studies were conducted in the 1970's to better understand the fate of plutonium in the desert that included studies of depth distribution and dust resuspension. More recently, plutonium particle distribution in the soil profile was detected using autoradiography. The results to date demonstrate the vertical migration of plutonium particles to depths in excess of 30 cm in this arid vadose zone. While plutonium migration at the Nevada Test Site has been and continues to be a concern, these field experiments have become analog sites for the

A BENCHMARKING ANALYSIS FOR FIVE RADIONUCLIDE VADOSE ZONE MODELS (CHAIN, MULTIMED_DP, FECTUZ, HYDRUS, AND CHAIN 2D) IN SOIL SCREENING LEVEL CALCULATIONS

Science.gov (United States)

Five radionuclide vadose zone models with different degrees of complexity (CHAIN, MULTIMED_DP, FECTUZ, HYDRUS, and CHAIN 2D) were selected for use in soil screening level (SSL) calculations. A benchmarking analysis between the models was conducted for a radionuclide (99Tc) rele...

Modeling non-steady state radioisotope transport in the vadose zone--A case study using uranium isotopes at Pena Blanca, Mexico

Energy Technology Data Exchange (ETDEWEB)

Ku, T. L.; Luo, S.; Goldstein, S. J.; Murrell, M. T.; Chu, W. L.; Dobson, P. F.

2009-06-01

Current models using U- and Th-series disequilibria to study radioisotope transport in groundwater systems mostly consider a steady-state situation. These models have limited applicability to the vadose zone (UZ) where the concentration and migratory behavior of radioisotopes in fluid are often transitory. We present here, as a first attempt of its kind, a model simulating the non-steady state, intermittent fluid transport in vadose layers. It provides quantitative constraints on in-situ migration of dissolved and colloidal radioisotopes in terms of retardation factor and rock-water interaction (or water transit) time. For uranium, the simulation predicts that intermittent flushing in the UZ leads to a linear relationship between reciprocal U concentration and {sup 234}U/{sup 238}U ratio in percolating waters, with the intercept and slope bearing information on the rates of dissolution and {alpha}-recoil of U isotopes, respectively. The general validity of the model appears to be borne out by the measurement of uranium isotopes in UZ waters collected at various times over a period during 1995-2006 from a site in the Pena Blanca mining district, Mexico, where the Nopal I uranium deposit is located. Enhanced {sup 234}U/{sup 238}U ratios in vadose-zone waters resulting from lengthened non-flushing time as prescribed by the model provide an interpretative basis for using {sup 234}U/{sup 238}U in cave calcites to reconstruct the regional changes in hydrology and climate. We also provide a theoretical account of the model's potential applications using radium isotopes.

Perched-Water Evaluation for the Deep Vadose Zone Beneath the B, BX, and BY Tank Farms Area of the Hanford Site

Energy Technology Data Exchange (ETDEWEB)

Truex, Michael J.; Oostrom, Martinus; Carroll, KC; Chronister, Glen B.

2013-06-28

Perched-water conditions have been observed in the vadose zone above a fine-grained zone that is located a few meters above the water table within the B, BX, and BY Tank Farms area. The perched water contains elevated concentrations of uranium and technetium-99. This perched-water zone is important to consider in evaluating the future flux of contaminated water into the groundwater. The study described in this report was conducted to examine the perched-water conditions and quantitatively evaluate 1) factors that control perching behavior, 2) contaminant flux toward groundwater, and 3) associated groundwater impact.

Monitoring plan for borehole logging at 216-Z-1A Tile Field, 216-Z-9 Trench, and 216-Z-12 Crib

International Nuclear Information System (INIS)

Horton, D.G.

1998-04-01

This plan describes the fiscal year 1998 vadose monitoring of three inactive, liquid waste disposal facilities associated with the Plutonium Finishing Plant (Z-Plant): the 216-Z-1A Tile Field, the 216-Z-9 Trench, and the 216-Z-12 Crib. Monitoring will consist of spectral gamma ray logging of 21 boreholes. This plan describes the physical characteristics of the facilities, their operational histories, the subsurface geology and known contamination distribution at each facility. The plan then describes the specific monitoring to be done including the boreholes to be logged, the methods of data acquisition, data reduction, and data evaluation, and finally, the quality control, data management and data reporting for this effort. The three liquid waste disposal facilities at the Z Plant were chosen to be monitored because they were identified as containing some of the most significant sources of radioactive contamination in the Hanford vadose zone. Johnson's analysis was based on the relative hazard obtained by combining curie quantities disposed to the facilities with appropriate health risk standards. The basic question to be addressed by this logging activity addresses the configuration of subsurface contamination since it was last measured. Historical data from the 216-Z-1A Tile Field, the 216-Z-9 Trench, and the 216-Z-12 Crib form the baseline for comparisons to answer this question

Underground Corrosion of Activated Metals in an Arid Vadose Zone Environment

International Nuclear Information System (INIS)

Adler Flitton, M.K; Mizia, R.E.; Bishop, C.W.

2001-01-01

The subsurface radioactive disposal site located at the Idaho National Engineering and Environmental Laboratory contains neutron-activated metals from nonfuel nuclear-reactor- core components. A long-term corrosion test is being conducted to obtain site-specific corrosion rates to support efforts to more accurately estimate the transfer of activated elements in an arid vadose zone environment. The tests use nonradioactive metal coupons representing the prominent neutron-activated material buried at the disposal location, namely, Type 304L stainless steel, Type 315L stainless steel, nickel-chromium alloy (UNS NO7718), beryllium, aluminum 6061-T6, and a zirconium alloy, (UNS R60804). In addition, carbon steel (the material presently used in the cask disposal liners and other disposal containers) and a duplex stainless steel (UNS S32550) (the proposed material for the high- integrity disposal containers) are also included in the test program. This paper briefly describes the test program and presents the early corrosion rate results after 1 year and 3 years of underground exposure

Chromium(VI) generation in vadose zone soils and alluvial sediments of the southwestern Sacramento Valley, California: a potential source of geogenic Cr(VI) to groundwater

Science.gov (United States)

Mills, Christopher T.; Morrison, Jean M.; Goldhaber, Martin B.; Ellefsen, Karl J.

2011-01-01

Concentrations of geogenic Cr(VI) in groundwater that exceed the World Health Organization’s maximum contaminant level for drinking water (50 μg L−1) occur in several locations globally. The major mechanism for mobilization of this Cr(VI) at these sites is the weathering of Cr(III) from ultramafic rocks and its subsequent oxidation on Mn oxides. This process may be occurring in the southern Sacramento Valley of California where Cr(VI) concentrations in groundwater can approach or exceed 50 μg L−1. To characterize Cr geochemistry in the area, samples from several soil auger cores (approximately 4 m deep) and drill cores (approximately 25 m deep) were analyzed for total concentrations of 44 major, minor and trace elements, Cr associated with labile Mn and Fe oxides, and Cr(VI). Total concentrations of Cr in these samples ranged from 140 to 2220 mg per kg soil. Between 9 and 70 mg per kg soil was released by selective extractions that target Fe oxides, but essentially no Cr was associated with the abundant reactive Mn oxides (up to ~1000 mg hydroxylamine-reducible Mn per kg soil was present). Both borehole magnetic susceptibility surveys performed at some of the drill core sites and relative differences between Cr released in a 4-acid digestion versus total Cr (lithium metaborate fusion digestion) suggest that the majority of total Cr in the samples is present in refractory chromite minerals transported from ultramafic exposures in the Coast Range Mountains. Chromium(VI) in the samples studied ranged from 0 to 42 μg kg−1, representing a minute fraction of total Cr. Chromium(VI) content was typically below detection in surface soils (top 10 cm) where soil organic matter was high, and increased with increasing depth in the soil auger cores as organic matter decreased. Maximum concentrations of Cr(VI) were up to 3 times greater in the deeper drill core samples than the shallow auger cores. Although Cr(VI) in these vadose zone soils and sediments was only a

Diffusional mass transport phenomena in the buffer material and damaged zone of a borehole wall in an underground nuclear fuel waste vault

International Nuclear Information System (INIS)

Page, S.; Cheung, S.C.H.

1983-06-01

The effects of the geometry of the borehole and the characteristics of the damaged borehole rock wall on the movement of the radionuclides from an underground nuclear waste vault have been studied. The results show that radionuclide transport will occur mainly through the buffer into the damaged zone of the borehole wall. As the degree of facturing of the damaged zone increases, the total radionuclide flux will increase up to a limit which can be approximated by a one-dimensional radial diffusion model. For large degrees of fracturing of the damaged zone, an increase in the radial buffer material thickness will decrease the total flux, whereas, for small degrees of fracturing, an increase in the radial buffer thickness may slightly increase the total flux. Increasing the vertical buffer thickness will significantly decrease the total flux when the degree of fracturing of the damaged zone is small. An increase in the vertical extent of the damaged zone will cause an increase in total flux

Isotropic events observed with a borehole array in the Chelungpu fault zone, Taiwan.

Science.gov (United States)

Ma, Kuo-Fong; Lin, Yen-Yu; Lee, Shiann-Jong; Mori, Jim; Brodsky, Emily E

2012-07-27

Shear failure is the dominant mode of earthquake-causing rock failure along faults. High fluid pressure can also potentially induce rock failure by opening cavities and cracks, but an active example of this process has not been directly observed in a fault zone. Using borehole array data collected along the low-stress Chelungpu fault zone, Taiwan, we observed several small seismic events (I-type events) in a fluid-rich permeable zone directly below the impermeable slip zone of the 1999 moment magnitude 7.6 Chi-Chi earthquake. Modeling of the events suggests an isotropic, nonshear source mechanism likely associated with natural hydraulic fractures. These seismic events may be associated with the formation of veins and other fluid features often observed in rocks surrounding fault zones and may be similar to artificially induced hydraulic fracturing.

Using the natural biodegradation potential of shallow soils for in-situ remediation of deep vadose zone and groundwater.

Science.gov (United States)

Avishai, Lior; Siebner, Hagar; Dahan, Ofer; Ronen, Zeev

2017-02-15

In this study, we examined the ability of top soil to degrade perchlorate from infiltrating polluted groundwater under unsaturated conditions. Column experiments designed to simulate typical remediation operation of daily wetting and draining cycles of contaminated water amended with an electron donor. Covering the infiltration area with bentonite ensured anaerobic conditions. The soil remained unsaturated, and redox potential dropped to less than -200mV. Perchlorate was reduced continuously from ∼1150mg/L at the inlet to ∼300mg/L at the outlet in daily cycles. Removal efficiency was between 60 and 84%. No signs of bioclogging were observed during three operation months although occasional iron reduction observed due to excess electron donor. Changes in perchlorate reducing bacteria numbers were inferred from an increased in pcrA gene abundances from ∼10 5 to 10 7 copied per gram at the end of the experiment indicating the growth of perchlorate-reducing bacteria. We proposed that the topsoil may serve as a bioreactor to treat high concentrations of perchlorate from the contaminated groundwater. The treated water that infiltrates from the topsoil through the vadose zone could be used to flush perchlorate from the deep vadose zone into the groundwater where it is retrieved again for treatment in the topsoil. Copyright © 2016 Elsevier B.V. All rights reserved.

Building Conceptual Models of Field-Scale Uranium Reactive Transport in a Dynamic Vadose Zone-Aquifer-River System

International Nuclear Information System (INIS)

Yabusaki, Steven B.; Fang, Yilin; Waichler, Scott R.

2008-01-01

Subsurface simulation is being used to build, test, and couple conceptual process models to better understand controls on a 0.4 km by 1.0 km uranium plume that has persisted above the drinking water standard in the groundwater of the Hanford 300 Area over the last 15 years. At this site, uranium-contaminated sediments in the vadose zone and aquifer are subject to significant variations in water levels and velocities driven by the diurnal, weekly, seasonal, and episodic Columbia River stage dynamics. Groundwater flow reversals typically occur twice a day with significant exchange of river water and groundwater in the near-river aquifer. Mixing of the dilute solution chemistry of the river with the groundwater complicates the uranium sorption behavior as the mobility of U(VI) has been shown experimentally to be a function of pH, carbonate, calcium, and uranium. Furthermore, uranium mass transfer between solid and aqueous phases has been observed to be rate-limited in the context of the high groundwater velocities resulting from the river stage fluctuations and the highly transmissive sediments (hydraulic conductivities ∼1500 m/d). One- and two-dimensional vertical cross-sectional simulations of variably-saturated flow and reactive transport, based on laboratory-derived models of distributed rate mass transfer and equilibrium multicomponent surface complexation, are used to assess uranium transport at the dynamic vadose zone aquifer interface as well as changes to uranium mobility due to incursions of river water into the aquifer

Interpretation of vadose zone monitoring system data near Engineered Trench 1

Energy Technology Data Exchange (ETDEWEB)

Flach, G. P. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Whiteside, T. S. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2016-12-12

The E-Area Vadose Zone Monitoring System (VZMS) includes lysimeter sampling points at many locations alongside and angling beneath the Engineered Trench #1 (ET1) disposal unit footprint. The sampling points for ET1 were selected for this study because collectively they showed consistently higher tritium (H-3) concentrations than lysimeters associated with other trench units. The VZMS tritium dataset for ET1 from 2001 through 2015 comprises concentrations at or near background levels at approximately half of locations through time, concentrations up to about 600 pCi/mL at a few locations, and concentrations at two locations that have exceeded 1000 pCi/mL. The highest three values through 2015 were 6472 pCi/mL in 2014 and 4533 pCi/mL in 2013 at location VL-17, and 3152 pCi/mL in 2007 at location VL-15. As a point of reference, the drinking water standard for tritium and a DOE Order 435.1 performance objective in the saturated zone at the distant 100-meter facility perimeter is 20 pCi/mL. The purpose of this study is to assess whether these elevated concentrations are indicative of a general trend that could challenge 2008 E-Area Performance Assessment (PA) conclusions, or are isolated perturbations that when considered in the context of an entire disposal unit would support PA conclusions.

Deep Vadose Zone Treatability Test for the Hanford Central Plateau. Interim Post-Desiccation Monitoring Results, Fiscal Year 2015

Energy Technology Data Exchange (ETDEWEB)

Truex, Michael J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Strickland, Christopher E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Oostrom, Martinus [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Johnson, Christian D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Tartakovsky, Guzel D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Johnson, Timothy C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Clayton, Ray E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Chronister, Glen B. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2015-09-01

A field test of desiccation is being conducted as an element of the Deep Vadose Zone Treatability Test Program. The active desiccation portion of the test has been completed. Monitoring data have been collected at the field test site during the post-desiccation period and are reported herein. This is an interim data summary report that includes about 4 years of post-desiccation monitoring data. The DOE field test plan proscribes a total of 5 years of post-desiccation monitoring.

Soil Desiccation Techniques Strategies For Immobilization Of Deep Vadose Contaminants At The Hanford Central Plateau

International Nuclear Information System (INIS)

Benecke, M.W.; Chronister, G.B.; Truex, M.J.

2012-01-01

Deep vadose zone contamination poses some of the most difficult remediation challenges for the protection of groundwater at the Hanford Site where processes and technologies are being developed and tested for use in the on-going effort to remediate mobile contamination in the deep vadose zone, the area deep beneath the surface. Historically, contaminants were discharged to the soil along with significant amounts of water, which continues to drive contaminants deeper in the vadose zone toward groundwater. Soil desiccation is a potential in situ remedial technology well suited for the arid conditions and the thick vadose zone at the Hanford Site. Desiccation techniques could reduce the advance of contaminants by removing the pore water to slow the rate of contaminants movement toward groundwater. Desiccation technologies have the potential to halt or slow the advance of contaminants in unsaturated systems, as well as aid in reduction of contaminants from these same areas. Besides reducing the water flux, desiccation also establishes capillary breaks that would require extensive rewetting to resume pore water transport. More importantly, these techniques have widespread application, whether the need is to isolate radio nuclides or address chemical contaminant issues. Three different desiccation techniques are currently being studied at Hanford.

Characterization of crystalline rocks in deep boreholes. The Kola, Krivoy Rog and Tyrnauz boreholes

International Nuclear Information System (INIS)

1992-12-01

SKB studies, as one alternative, the feasibility of disposing of spent nuclear fuel in very deep boreholes. As a part of this work NEDRA has compiled geoscientific data from three superdeep boreholes within the former Soviet Union. The holes considered were: the Kola borehole, 12261 m deep and located on the Kola Peninsula, the Krivoy Rog borehole, 5000 m deep and located in Ukraine, and the Tyrnauz borehole, 4001 m deep and located between the Black Sea and the Caspian Sea. These boreholes all penetrate crystalline formations, but major differences are found when their tectonic environments are compared. Excluding the uppermost horizon affected by surface phenomena, data do not indicate any general correlation between depth and the state of rock fracturing, which is instead governed by site specific, lithological and tectonical factors. This applies also to fracture zones, which are found at similar frequencies at all depths. As opposed to the structural data, the hydrogeological and hydrochemical information reveals a vertical zonation, with clear similarities between the three boreholes. An upper zone with active circulation and fresh or slightly mineralized groundwaters reaches down 1000-2000 m. The interval from 1000-2000 m down to 4000-5000 m can be characterized as a transition zone with lower circulation rates and gradually increasing mineralisation. Below 4000-5000 m, strongly mineralized, stagnant, juvenile or metamorphogenic waters are found. Geothermal data verify the existence of this zonation. 28 figs, 30 tabs

Geochemical Characterization of Chromate Contamination in the 100 Area Vadose Zone at the Hanford Site

Energy Technology Data Exchange (ETDEWEB)

Dresel, P. Evan; Qafoku, Nikolla; McKinley, James P.; Fruchter, Jonathan S.; Ainsworth, Calvin C.; Liu, Chongxuan; Ilton, Eugene S.; Phillips, J. L.

2008-07-16

The major objectives of the proposed study were to: 1.) determine the leaching characteristics of hexavalent chromium [Cr(VI)] from contaminated sediments collected from 100 Area spill sites; 2.) elucidate possible Cr(VI) mineral and/or chemical associations that may be responsible for Cr(VI) retention in the Hanford Site 100 Areas through the use of i.) macroscopic leaching studies and ii.) microscale characterization of contaminated sediments; and 3.) provide information to construct a conceptual model of Cr(VI) geochemistry in the Hanford 100 Area vadose zone. In addressing these objectives, additional benefits accrued were: (1) a fuller understanding of Cr(VI) entrained in the vadose zone that will that can be utilized in modeling potential Cr(VI) source terms, and (2) accelerating the Columbia River 100 Area corridor cleanup by providing valuable information to develop remedial action based on a fundamental understanding of Cr(VI) vadose zone geochemistry. A series of macroscopic column experiments were conducted with contaminated and uncontaminated sediments to study Cr(VI) desorption patterns in aged and freshly contaminated sediments, evaluate the transport characteristics of dichromate liquid retrieved from old pipelines of the 100 Area; and estimate the effect of strongly reducing liquid on the reduction and transport of Cr(VI). Column experiments used the < 2 mm fraction of the sediment samples and simulated Hanford groundwater solution. Periodic stop-flow events were applied to evaluate the change in elemental concentration during time periods of no flow and greater fluid residence time. The results were fit using a two-site, one dimensional reactive transport model. Sediments were characterized for the spatial and mineralogical associations of the contamination using an array of microscale techniques such as XRD, SEM, EDS, XPS, XMP, and XANES. The following are important conclusions and implications. Results from column experiments indicated that most

Assessing the impact of dairy waste lagoons on groundwater quality using a spatial analysis of vadose zone and groundwater information in a coastal phreatic aquifer.

Science.gov (United States)

Baram, S; Kurtzman, D; Ronen, Z; Peeters, A; Dahan, O

2014-01-01

Dairy waste lagoons are considered to be point sources of groundwater contamination by chloride (Cl(-)), different nitrogen-species and pathogens/microorganisms. The objective of this work is to introduce a methodology to assess the past and future impacts of such lagoons on regional groundwater quality. The method is based on a spatial statistical analysis of Cl(-) and total nitrogen (TN) concentration distributions in the saturated and the vadose (unsaturated) zones. The method provides quantitative data on the relation between the locations of dairy lagoons and the spatial variability in Cl(-) and TN concentrations in groundwater. The method was applied to the Beer-Tuvia region, Israel, where intensive dairy farming has been practiced for over 50 years above the local phreatic aquifer. Mass balance calculations accounted for the various groundwater recharge and abstraction sources and sinks in the entire region. The mass balances showed that despite the small surface area covered by the dairy lagoons in this region (0.8%), leachates from lagoons have contributed 6.0% and 12.6% of the total mass of Cl(-) and TN (mainly as NO3(-)-N) added to the aquifer. The chemical composition of the aquifer and vadose zone water suggested that irrigated agricultural activity in the region is the main contributor of Cl(-) and TN to the groundwater. A low spatial correlation between the Cl(-) and NO3(-)-N concentrations in the groundwater and the on-land location of the dairy farms strengthened this assumption, despite the dairy waste lagoon being a point source for groundwater contamination by Cl(-) and NO3(-)-N. Mass balance calculations, for the vadose zone of the entire region, indicated that drying of the lagoons would decrease the regional groundwater salinization process (11% of the total Cl(-) load is stored under lagoons). A more considerable reduction in the groundwater contamination by NO3(-)-N is expected (25% of the NO3(-)-N load is stored under lagoons). Results

A National Roadmap for Vadose Zone Science and Technology

Energy Technology Data Exchange (ETDEWEB)

Kowall, Stephen Jacob

2001-08-01

This roadmap is a means of achieving, to the best of our current knowledge, a reasonable scientific understanding of how contaminants of all forms move in the vadose geological environments. This understanding is needed to reduce the present uncertainties in predicting contaminant movement, which in turn will reduce the uncertainties in remediation decisions.

Water and Solute Transport in Arid Vadose Zones: Innovations in Measurement and Analysis

International Nuclear Information System (INIS)

Tyler, S W.; Scanlon, Bridget R.; Gee, Glendon W.; Allison, G B.; Parlange, M. B.; Hopmans, J. W.

1999-01-01

Understanding the physics of flow and transport through the vadose zone has advanced significantly in the last three decades. These advances have been made primarily in humid regions or in irrigated agricultural settings. While some of the techniques are useful, many are not suited to arid regions. The fluxes of water and solutes typically found in arid regions are often orders of magnitude smaller than those found in agricultural settings, while the time scales for transport can be orders of magnitude larger. The depth over which transport must be characterized is also often much greater than in humid regions. Rather than relying on advances in applied tracers, arid-zone researchers have developed natural tracer techniques that are capable of quantifying transport over tens to thousands of years. Techniques have been developed to measure the hydraulic properties of sediments at all water contents, including the very dry range and at far greater depths. As arid and semiarid regions come under increased development pressures for such activities as hazardous- and radioactive-waste disposal, the development of techniques and the understanding of water and solute transport have become crucial components in defining the environmental impacts of activities at the landsurface

Monitoring the vadose zone in fractured tuff, Yucca Mountain, Nevada

International Nuclear Information System (INIS)

Montazer, P.; Weeks, E.P.; Thamir, F.; Yard, S.N.; Hofrichter, P.B.

1985-01-01

Unsaturated tuff beneath Yucca Mountain, Nevada, is being evaluated by the US Department of Energy as a host rock for a potential repository for high-level radioactive waste. As part of the Nevada Nuclear Waste Storage Investigations Project of the US Department of Energy, the US Geological Survey has been conducting hydrologic, geologic, and geophysical investigations at Yucca Mountain and the surrounding region to provide data evaluation of the potential suitability of the site. Hydrologic investigations of the unsaturated zone at this site were started in 1982. A 17.5-inch- (44.5-centimeter-) diameter borehole (USW UZ-1) was drilled by the reverse-air vacuum-drilling technique to a depth of 1269 feet (387 meters). This borehole was instrumented at 33 depth levels. At 15 of the levels, 3 well screens were embedded in coarse-sand columns. The sand columns were isolated from each other by thin layers of bentonite, columns of silica flour, and isolation plugs consisting of expansive cement. Thermocouple psychrometers and pressure transducers were installed within the screens and connected to the data-acquisition system at the land surface through thermocouple and logging cables. Two of the screens at each level were equipped with access tubes to allow collection of pore-gas samples. In addition to these instruments, 18 heat-dissipation probes were installed within the columns of silica flour, some of which also had thermocouple psychrometers. 20 refs., 13 figs., 2 tabs

Deep Vadose Zone Treatability Test for the Hanford Central Plateau: Interim Post-Desiccation Monitoring Results

Energy Technology Data Exchange (ETDEWEB)

Truex, Michael J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Oostrom, Martinus [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Strickland, Christopher E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Johnson, Timothy C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Johnson, Christian D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Clayton, Ray E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Chronister, Glen B. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2013-09-01

A field test of desiccation is being conducted as an element of the deep vadose zone treatability test program. Desiccation technology relies on removal of water from a portion of the subsurface such that the resultant low moisture conditions inhibit downward movement of water and dissolved contaminants. Previously, a field test report (Truex et al. 2012a) was prepared describing the active desiccation portion of the test and initial post-desiccation monitoring data. Additional monitoring data have been collected at the field test site during the post-desiccation period and is reported herein along with interpretation with respect to desiccation performance. This is an interim report including about 2 years of post-desiccation monitoring data.

Modeling non-steady state radioisotope transport in the vadose zone - A case study using uranium isotopes at Peña Blanca, Mexico

Science.gov (United States)

Ku, T. L.; Luo, S.; Goldstein, S. J.; Murrell, M. T.; Chu, W. L.; Dobson, P. F.

2009-10-01

Current models using U- and Th-series disequilibria to study radioisotope transport in groundwater systems mostly consider a steady-state situation. These models have limited applicability to the vadose zone (UZ) where the concentration and migratory behavior of radioisotopes in fluid are often transitory. We present here, as a first attempt of its kind, a model simulating the non-steady state, intermittent fluid transport in vadose layers. It provides quantitative constraints on in-situ migration of dissolved and colloidal radioisotopes in terms of retardation factor and rock-water interaction (or water transit) time. For uranium, the simulation predicts that intermittent flushing in the UZ leads to a linear relationship between reciprocal U concentration and 234U/ 238U ratio in percolating waters, with the intercept and slope bearing information on the rates of dissolution and α-recoil of U isotopes, respectively. The general validity of the model appears to be borne out by the measurement of uranium isotopes in UZ waters collected at various times over a period during 1995-2006 from a site in the Peña Blanca mining district, Mexico, where the Nopal I uranium deposit is located. Enhanced 234U/ 238U ratios in vadose-zone waters resulting from lengthened non-flushing time as prescribed by the model provide an interpretative basis for using 234U/ 238U in cave calcites to reconstruct the regional changes in hydrology and climate. We also provide a theoretical account of the model's potential applications using radium isotopes.

Vadose zone characterization of highly radioactive contaminated soil at the Hanford Site

International Nuclear Information System (INIS)

Buckmaster, M.A.

1993-05-01

The Hanford Site in south-central Washington State contains over 1500 identified waste sites and numerous groundwater plumes that will be characterized and remediated over the next 30 years. As a result of the Hanford Federal Facility Agreement and Consent Order, the US Department of Energy has initiated a remedial investigation/feasibility study at the 200-BP-1 operable unit. The 200-BP-1 remedial investigation is the first Comprehensive Environmental Response, Compensation, and Liability Act of 1980 investigation on the Hanford Site that involves drilling into highly radioactive and chemically contaminated soils. The initial phase of site characterization was designed to assess the nature and extent of contamination associated with the source waste site within the 200-BP-1 operable unit. Characterization activities consisted of drilling and sampling the waste site, chemical and physical analysis of samples, and development of a conceptual vadose zone model. Predicted modeling concentrations compared favorably to analytical data collected during the initial characterization activities

Vadose Zone Fate and Transport Simulation of Chemicals Associated with Coal Seam Gas Extraction

Science.gov (United States)

Simunek, J.; Mallants, D.; Jacques, D.; Van Genuchten, M.

2017-12-01

The HYDRUS-1D and HYDRUS (2D/3D) computer software packages are widely used finite element models for simulating the one-, and two- or three-dimensional movement of water, heat, and multiple solutes in variably-saturated media, respectively. While the standard HYDRUS models consider only the fate and transport of individual solutes or solutes subject to first-order degradation reactions, several specialized HYDRUS add-on modules can simulate far more complex biogeochemical processes. The objective of this presentation is to provide an overview of the HYDRUS models and their add-on modules, and to demonstrate applications of the software to the subsurface fate and transport of chemicals involved in coal seam gas extraction and water management operations. One application uses the standard HYDRUS model to evaluate the natural soil attenuation potential of hydraulic fracturing chemicals and their transformation products in case of an accidental release. By coupling the processes of retardation, first-order degradation and convective-dispersive transport of the biocide bronopol and its degradation products, we demonstrated how natural attenuation reduces initial concentrations by more than a factor of hundred in the top 5 cm of the vadose zone. A second application uses the UnsatChem module to explore the possible use of coal seam gas produced water for sustainable irrigation. Simulations with different irrigation waters (untreated, amended with surface water, and reverse osmosis treated) provided detailed results regarding chemical indicators of soil and plant health, notably SAR, EC and sodium concentrations. A third application uses the coupled HYDRUS-PHREEQC module to analyze trace metal transport involving cation exchange and surface complexation sorption reactions in the vadose zone leached with coal seam gas produced water following some accidental water release scenario. Results show that the main process responsible for trace metal migration is complexation of

Vadose Zone Nitrate Transport Dynamics Resulting from Agricultural Groundwater Banking

Science.gov (United States)

Murphy, N. P.; McLaughlin, S.; Dahlke, H. E.

2017-12-01

In recent years, California's increased reliance on groundwater resources to meet agricultural and municipal demands has resulted in significant overdraft and water quality issues. Agricultural groundwater banking (AGB) has emerged as a promising groundwater replenishment opportunity in California; AGB is a form of managed aquifer recharge where farmland is flooded during the winter using excess surface water in order to recharge the underlying groundwater. Suitable farmland that is connected to water delivery systems is available for AGB throughout the Central Valley. However, questions remain how AGB could be implemented on fertilized agricultural fields such that nitrate leaching from the root zone is minimized. Here, we present results from field and soil column studies that investigate the transport dynamics of nitrogen in the root and deeper vadose zone during flooding events. We are specifically interested in estimating how timing and duration of flooding events affect percolation rates, leaching and nitrification/denitrification processes in three soil types within the Central Valley. Laboratory and field measurements include nitrogen (NO3-, NH4+, NO2-, N2O), redox potentials, total organic carbon, dissolved oxygen, moisture content and EC. Soil cores are collected in the field before and after recharge events up to a depth of 4m, while other sensors monitor field conditions continuously. Preliminary results from the three field sites show that significant portions of the applied floodwater (12-62 cm) infiltrated below the root zone: 96.1% (Delhi), 88.6% (Modesto) and 76.8% (Orland). Analysis of the soil cores indicate that 70% of the residual nitrate was flushed from the sandy soil, while the fine sandy loam showed only a 5% loss and in some cores even an increase in soil nitrate (in the upper 20cm). Column experiments support these trends and indicate that increases in soil nitrate in the upper root zone might be due to organic nitrogen mineralization and

Vandose Zone Characterization Project at the Hanford Tank Farms: SX Tank Farm Report

International Nuclear Information System (INIS)

Brodeur, J.R.; Koizumi, C.J.; Bertsch, J.F.

1996-09-01

The SX Tank Farm is located in the southwest portion of the 200 West Area of the Hanford Site. This tank farm consists of 15 single-shell tanks (SSTs), each with an individual capacity of 1 million gallons (gal). These tanks currently store high-level nuclear waste that was primarily generated from what was called the oxidation-reduction or open-quotes REDOXclose quotes process at the S-Plant facility. Ten of the 15 tanks are listed in Hanlon as open-quotes assumed leakersclose quotes and are known to have leaked various amounts of high-level radioactive liquid to the vadose zone sediment. The current liquid content of each tank varies, but the liquid from known leaking tanks has been removed to the extent possible. In 1994, the U.S. Department of Energy Richland Office (DOE-RL) requested the DOE Grand Junction Projects Office (GJPO), Grand Junction, Colorado, to perform a baseline characterization of contamination in the vadose zone at all the SST farms with spectral gamma-ray logging of boreholes surrounding the tanks. The SX Tank Farm geophysical logging was completed, and the results of this baseline characterization are presented in this report

Accurate measurements of vadose zone fluxes using automated equilibrium tension plate lysimeters: A synopsis of results from the Spydia research facility, New Zealand.

Science.gov (United States)

Wöhling, Thomas; Barkle, Greg; Stenger, Roland; Moorhead, Brian; Wall, Aaron; Clague, Juliet

2014-05-01

Automated equilibrium tension plate lysimeters (AETLs) are arguably the most accurate method to measure unsaturated water and contaminant fluxes below the root zone at the scale of up to 1 m². The AETL technique utilizes a porous sintered stainless-steel plate to provide a comparatively large sampling area with a continuously controlled vacuum that is in "equilibrium" with the surrounding vadose zone matric pressure to ensure measured fluxes represent those under undisturbed conditions. This novel lysimeter technique was used at an intensive research site for investigations of contaminant pathways from the land surface to the groundwater on a sheep and beef farm under pastoral land use in the Tutaeuaua subcatchment, New Zealand. The Spydia research facility was constructed in 2005 and was fully operational between 2006 and 2011. Extending from a central access caisson, 15 separately controlled AETLs with 0.2 m² surface area were installed at five depths between 0.4 m and 5.1 m into the undisturbed volcanic vadose zone materials. The unique setup of the facility ensured minimum interference of the experimental equipment and external factors with the measurements. Over the period of more than five years, a comprehensive data set was collected at each of the 15 AETL locations which comprises of time series of soil water flux, pressure head, volumetric water contents, and soil temperature. The soil water was regularly analysed for EC, pH, dissolved carbon, various nitrogen compounds (including nitrate, ammonia, and organic N), phosphorus, bromide, chloride, sulphate, silica, and a range of other major ions, as well as for various metals. Climate data was measured directly at the site (rainfall) and a climate station at 500m distance. The shallow groundwater was sampled at three different depths directly from the Spydia caisson and at various observation wells surrounding the facility. Two tracer experiments were conducted at the site in 2009 and 2010. In the 2009

Chaotic-dynamical conceptual model to describe fluid flow and contaminant transport in a fractured vadose zone. 1998 annual progress report

International Nuclear Information System (INIS)

Doughty, C.; Dragila, M.I.; Faybishenko, B.; Podgorney, R.K.; Stoops, T.M.; Wheatcraft, S.W.; Wood, T.R.

1998-01-01

'DOE faces the remediation of numerous contaminated sites, such as those at Hanford, INEEL, LLNL, and LBNL, where organic and/or radioactive wastes were intentionally or accidentally released to the vadose zone from surface spills, underground tanks, cribs, shallow ponds, and deep wells. Migration of these contaminants through the vadose zone has lead to the contamination of or threatens to contaminate underlying groundwater. A key issue in choosing a corrective action plan to clean up contaminated sites is to determine the location, total mass, mobility and travel time to receptors for contaminants moving in the vadose zone. These problems are difficult to solve in a technically defensible and accurate manner because contaminants travel downward intermittently through narrow pathways driven by variations in environmental conditions. These preferential pathways can be difficult to find and predict. The primary objective of this project is to determine if and when dynamical chaos theory can be used to investigate infiltration of fluid and contaminant transport in heterogeneous soils and fractured rocks. The objective of this project is being achieved through the following Activities (1) Evaluation of chaotic behavior of flow in laboratory and field experiments using methods from non-linear dynamics; (2) Evaluation of the impact these dynamics may have on contaminant transport through heterogeneous fractured rocks and soils, and how it can be used to guide remediation efforts; (3) Development of a conceptual model and mathematical and numerical algorithms for flow and transport, which incorporate both: (a) the spatial variability of heterogeneous porous and fractured media, and (b) the description of the temporal dynamics of flow and transport, which may be chaotic; and (4) Development of appropriate experimental field and laboratory techniques needed to detect diagnostic parameters for chaotic behavior of flow. This approach is based on the assumption that spatial

Emerging organic pollutants in the vadose zone of a soil aquifer treatment system: Pore water extraction using positive displacement.

Science.gov (United States)

Sopilniak, Alexander; Elkayam, Roy; Rossin, Anna Voloshenko; Lev, Ovadia

2018-01-01

Trace organic compounds in effluents, water streams and aquifers are amply reported. However, the mobile pool of Emerging Organic Contaminants (EOCs) in the deep parts of the vadose zone is hard to estimate, due to difficulties in extraction of sufficient quantity of pore water. Here, we present a new methodology for depth profiling of EOCs in pore water by Positive Displacement Extraction (PDE): Pore water extraction from unsaturated soil samples is carried out by withdrawal of soil cores by direct-push drilling and infiltrating the core by organics free water. We show that EOC concentrations in the water eluted in the plateau region of the inverse breakthrough curve is equal to their pore water concentrations. The method was previously validated for DOC extraction, and here the scope of the methodology is extended to pore water extraction for organic pollutants analysis. Method characteristics and validation were carried out with atrazine, simazine, carbamazepine, venlafaxine, O-desmethylvenlafaxine and caffeine in the concentration range of several ng to several μg/liter. Validation was carried out by laboratory experiments on three different soils (sandy, sandy-clayey and clayey). Field studies in the vadose zone of a SAT system provided 27 m deep EOC profiles with less than 1.5 m spatial resolution. During the percolation treatment, carbamazepine remained persistent, while the other studied EOCs were attenuated to the extent of 50-99%.The highest degradation rate of all studied EOCs was in the aerobic zone. EOC levels based on PDE and extraction by centrifugation were compared, showing a positive bias for centrifugation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Inorganic carbon fluxes across the vadose zone of planted and unplanted soil mesocosms

DEFF Research Database (Denmark)

Thaysen, Eike Marie; Jacques, D.; Jessen, S.

2014-01-01

The efflux of carbon dioxide (CO2) from soils influences atmospheric CO2 concentrations and thereby climate change. The partitioning of inorganic carbon (C) fluxes in the vadose zone between emission to the atmosphere and to the groundwater was investigated to reveal controlling underlying...... mechanisms. Carbon dioxide partial pressure in the soil gas (pCO(2)), alkalinity, soil moisture and temperature were measured over depth and time in unplanted and planted (barley) mesocosms. The dissolved inorganic carbon (DIC) percolation flux was calculated from the pCO(2), alkalinity and the water flux...... to calculate the soil CO2 production. Carbon dioxide fluxes were modeled using the HP1 module of the Hydrus 1-D software. The average CO2 effluxes to the atmosphere from unplanted and planted mesocosm ecosystems during 78 days of experiment were 0.1 +/- 0.07 and 4.9 +/- 0.07 mu mol Cm-2 s(-1), respectively...

Electrical Resistance Tomography to monitor vadose water movement

International Nuclear Information System (INIS)

Ramirez, A.; Daily, W.; LaBrecque, D.

1991-01-01

We report results of one test in which Electrical Resistance Tomography (ERT) was used to map the changes in electrical resistivity in the vadose zone as a function of time while water infiltration occurred. The ERT images were used to infer shape and movement of the infiltration plume in the unsaturated soil. We supplied a continuous water source at a point about 10 feet below the surface (at the end of a shallow screened hole) for only a short time--2.5 hours. This pulsed source introduced a open-quote slug close-quote of water whose infiltration was followed to about 60 foot depth during a 23 hour period. The ERT images show resistivity decreases as the water content of the vadose zone increased while water was added to the soil; the resistivity of the soil later increased after the supply of water was cut-off and the induced soil moisture began to subside

300 Area Treatability Test: Laboratory Development of Polyphosphate Remediation Technology for In Situ Treatment of Uranium Contamination in the Vadose Zone and Capillary Fringe

Energy Technology Data Exchange (ETDEWEB)

Wellman, Dawn M.; Pierce, Eric M.; Bacon, Diana H.; Oostrom, Martinus; Gunderson, Katie M.; Webb, Samuel M.; Bovaird, Chase C.; Cordova, Elsa A.; Clayton, Eric T.; Parker, Kent E.; Ermi, Ruby M.; Baum, Steven R.; Vermeul, Vincent R.; Fruchter, Jonathan S.

2008-09-30

This report presents results from bench-scale treatability studies conducted under site-specific conditions to optimize the polyphosphate amendment for implementation of a field-scale technology demonstration to stabilize uranium within the 300 Area vadose and smear zones of the Hanford Site. The general treatability testing approach consisted of conducting studies with site sediment and under site conditions, to develop an effective chemical formulation and infiltration approach for the polyphosphate amendment under site conditions. Laboratory-scale dynamic column tests were used to 1) quantify the retardation of polyphosphate and its degradation products as a function of water content, 2) determine the rate of polyphosphate degradation under unsaturated conditions, 3) develop an understanding of the mechanism of autunite formation via the reaction of solid phase calcite-bound uranium and aqueous polyphosphate remediation technology, 4) develop an understanding of the transformation mechanism, the identity of secondary phases, and the kinetics of the reaction between uranyl-carbonate and -silicate minerals with the polyphosphate remedy under solubility-limiting conditions, and 5) quantify the extent and rate of uranium released and immobilized based on the infiltration rate of the polyphosphate remedy and the effect of and periodic wet-dry cycling on the efficacy of polyphosphate remediation for uranium in the vadose zone and smear zone.

Borehole geophysical and flowmeter data for eight boreholes in the vicinity of Jim Woodruff Lock and Dam, Lake Seminole, Jackson County, Florida

Science.gov (United States)

Clarke, John S.; Hamrick, Michael D.; Holloway, O. Gary

2011-01-01

Borehole geophysical logs and flowmeter data were collected in April 2011 from eight boreholes to identify the depth and orientation of cavernous zones within the Miocene Tampa Limestone in the vicinity of Jim Woodruff Lock and Dam in Jackson County, Florida. These data are used to assess leakage near the dam. Each of the eight boreholes was terminated in limestone at depths ranging from 84 to 104 feet. Large cavernous zones were encountered in most of the borings, with several exceeding 20-inches in diameter. The cavernous zones generally were between 1 and 5 feet in height, but a cavern in one of the borings reached a height of about 6 feet. The resistivity of limestone layers penetrated by the boreholes generally was less than 1,000 ohm-meters. Formation resistivity near the cavernous zones did not show an appreciable contrast from surrounding bedrock, probably because the bedrock is saturated, owing to its primary permeability. Measured flow rates in the eight boreholes determined using an electromagnetic flowmeter were all less than ±0.1 liter per second. These low flow rates suggest that vertical hydraulic gradients in the boreholes are negligible and that hydraulic head in the various cavernous zones shows only minor, if any, variation.

Colloid Genesis/Transport and Flow Pathway Alterations Resulting From Interactions of Reactive Waste Solutions and Hanford Vadose Zone Sediments

International Nuclear Information System (INIS)

Wan, Jiamin; Tokunaga, Tetsu K.

2001-01-01

Leakage of underground tanks containing high-level nuclear waste solutions has been identified at various DOE facilities. The Hanford Site is one the main facilities of concern, with about 2,300 to 3,400 m3 of leaked waste liquids. Radionuclides and other contaminants have been found in elevated concentrations in the vadose zone and groundwater underneath single shell tank farms. We do not currently know the mechanisms responsible for the unexpected deep migration of some contaminants through the vadose zone, and such understanding is urgently needed for planning remediation. Due to the extreme chemical conditions of the tank waste solutions (very high pH, aluminum concentration, and ionic strength), interactions between the highly reactive waste solutions and sediments underneath the tanks can result in dissolution of primary minerals of the sediments and precipitation of secondary phases including colloidal particles. Contaminants can sorb onto and/or co-precipitate with the secondary phases. Therefore transport of strongly associated contaminants on mobile colloids can be substantially greater than without colloids. The overall objective of this research is to improve our understanding on the effects of interactions between the tank waste solution and sediments on deep contaminant migration under Hanford Site conditions. This objective will be achieved through the following four tasks: (1) colloid generation and transport studies, (2) studies on sediment permeability and chemical composition alterations, (3) quantifying associations of contaminants with secondary colloids, and (4) studies on the combined effects of the aforementioned processes on deep contaminant migration

Borehole DC-12 hydrostratigraphic chart

International Nuclear Information System (INIS)

Gephart, R.E.

1981-09-01

This hydrostratigraphic chart identifies the basic stratigraphy and preliminary hydrologic testing results for Borehole DC-12. This borehole was cored through the Saddle Mountains and Wanapum basalt formations and into the Grande Ronde. Selected zones were hydrologically tested during coring

Borehole DC-14 hydrostratigraphic chart

International Nuclear Information System (INIS)

Gephart, R.E.

1981-09-01

This hydrostratigraphic chart identifies the basic stratigraphy and preliminary hydrologic testing results for Borehole DC-14. This borehole was cored through the Saddle Mountains and Wanapum basalt formations and into the Grande Ronde. Selected zones were hydrologically tested during coring

Borehole DC-15 hydrostratigraphic chart

International Nuclear Information System (INIS)

Gephart, R.E.

1981-09-01

This hydrostratigraphic chart identifies the basic stratigraphy and preliminary hydrologic testing results for Borehole DC-15. This borehole was cored through the Saddle Mountains and Wanapum basalt formations and into the Grande Ronde. Selected zones were hydrologically tested during coring

Pedotransfer functions for isoproturon sorption on soils and vadose zone materials.

Science.gov (United States)

Moeys, Julien; Bergheaud, Valérie; Coquet, Yves

2011-10-01

Sorption coefficients (the linear K(D) or the non-linear K(F) and N(F)) are critical parameters in models of pesticide transport to groundwater or surface water. In this work, a dataset of isoproturon sorption coefficients and corresponding soil properties (264 K(D) and 55 K(F)) was compiled, and pedotransfer functions were built for predicting isoproturon sorption in soils and vadose zone materials. These were benchmarked against various other prediction methods. The results show that the organic carbon content (OC) and pH are the two main soil properties influencing isoproturon K(D) . The pedotransfer function is K(D) = 1.7822 + 0.0162 OC(1.5) - 0.1958 pH (K(D) in L kg(-1) and OC in g kg(-1)). For low-OC soils (OC isoproturon sorption in soils in unsampled locations should rely, whenever possible, and by order of preference, on (a) site- or soil-specific pedotransfer functions, (b) pedotransfer functions calibrated on a large dataset, (c) K(OC) values calculated on a large dataset or (d) K(OC) values taken from existing pesticide properties databases. Copyright © 2011 Society of Chemical Industry.

Estimation of percolating water dynamics through the vadose zone of the Postojna cave on the basis of isotope composition

Directory of Open Access Journals (Sweden)

Janja Kogovšek

2007-12-01

Full Text Available Within the scope of monitoring water percolation through the 100-m thick vadose zone in the area of Postojnska jama continuous measurements of precipitation were carried out on the surface, and continuous measurements of water flowandphysicalandchemicalparametersof selected water trickles were performed under the surface. Occasional samples of percolating waters were taken for the analysis of water oxygen isotope composition. An exponential model of groundwater flowwaselaborated,bymeansofwhichtheretentiontime of water in individual trickles was estimated. Modelled retention times of groundwater range from 2.5 months to over one year.

Borehole radar applied to the characterization of hydraulically conductive fracture zones in crystalline rock

International Nuclear Information System (INIS)

Olsson, O.; Falk, L.; Forslund, O.; Lundmark, L.; Sandberg, E.

1992-01-01

This paper discusses the borehole radar system, RAMAC, developed within the framework of the International Stripa Project, which can be used in three different measuring modes; single-hole reflection, cross-hole reflection and cross-hole tomography. The reflection modes basically provide geometrical data on features located at some distance from the borehole. In addition the strength of the reflections indicate the contrast in electrical properties. Single-hole reflection data are cylindrically symmetrical with respect to the borehole, which means that a unique fracture orientation cannot be obtained. A method has been devised where absolute orientation of fracture zones is obtained by combining single-hole reflection data from adjacent holes. Similar methods for the analysis of cross-hole reflection data have also been developed and found to be efficient. The radar operates in the frequency range 20-60 MHz which gives a resolution of 1-3 m in crystalline rock. The investigation range obtained in the Stripa granite is approximately 100 m in the single-hole mode and 200-300 m in the cross-hole model. Variations in the arrival time and amplitude of the direct wave between transmitter and receiver have been used for cross-hole tomographic imaging to yield maps of radar velocity and attenuation. The cross-hole measurement configuration coupled with tomographic inversion has less resolution than the reflection methods but provides better quantitative estimates of the values of measured properties. The analysis of the radar data has provided a consistent description of the fracture zones at the Stripa Cross-hole site in agreement with both geological and geophysical observations

Laboratory investigations of the effects of nitrification-induced acidification on Cr cycling in vadose zone material partially derived from ultramafic rocks

Science.gov (United States)

Mills, Christopher T.; Goldhaber, Martin B.

2012-01-01

Sacramento Valley (California, USA) soils and sediments have high concentrations of Cr(III) because they are partially derived from ultramafic material. Some Cr(III) is oxidized to more toxic and mobile Cr(VI) by soil Mn oxides. Valley soils typically have neutral to alkaline pH at which Cr(III) is highly immobile. Much of the valley is under cultivation and is both fertilized and irrigated. A series of laboratory incubation experiments were conducted to assess how cultivation might impact Cr cycling in shallow vadose zone material from the valley. The first experiments employed low (7.1 mmol N per kg soil) and high (35 mmol N kg− 1) concentrations of applied (NH4)2SO4. Initially, Cr(VI) concentrations were up to 45 and 60% greater than controls in low and high incubations, respectively. After microbially-mediated oxidation of all NH4+, Cr(VI) concentrations dropped below control values. Increased nitrifying bacterial populations (estimated by measurement of phospholipid fatty acids) may have increased the Cr(VI) reduction capacity of the vadose zone material resulting in the observed decreases in Cr(VI). Another series of incubations employed vadose zone material from a different location to which low (45 meq kg− 1) and high (128 meq kg− 1) amounts of NH4Cl, KCl, and CaCl2 were applied. All treatments, except high concentration KCl, resulted in mean soil Cr(VI) concentrations that were greater than the control. High concentrations of water-leachable Ba2 + (mean 38 μmol kg− 1) in this treatment may have limited Cr(VI) solubility. A final set of incubations were amended with low (7.1 mmol N kg− 1) and high (35 mmol N kg− 1) concentrations of commercial liquid ammonium polyphosphate (APP) fertilizer which contained high concentrations of Cr(III). Soil Cr(VI) in the low APP incubations increased to a concentration of 1.8 μmol kg− 1 (5 × control) over 109 days suggesting that Cr(III) added with the APP fertilizer was more

Seasonal Variability in Vadose zone biodegradation at a crude oil pipeline rupture site

Science.gov (United States)

Sihota, Natasha J.; Trost, Jared J.; Bekins, Barbara; Berg, Andrew M.; Delin, Geoffrey N.; Mason, Brent E.; Warren, Ean; Mayer, K. Ulrich

2016-01-01

Understanding seasonal changes in natural attenuation processes is critical for evaluating source-zone longevity and informing management decisions. The seasonal variations of natural attenuation were investigated through measurements of surficial CO2 effluxes, shallow soil CO2 radiocarbon contents, subsurface gas concentrations, soil temperature, and volumetric water contents during a 2-yr period. Surficial CO2 effluxes varied seasonally, with peak values of total soil respiration (TSR) occurring in the late spring and summer. Efflux and radiocarbon data indicated that the fractional contributions of natural soil respiration (NSR) and contaminant soil respiration (CSR) to TSR varied seasonally. The NSR dominated in the spring and summer, and CSR dominated in the fall and winter. Subsurface gas concentrations also varied seasonally, with peak values of CO2 and CH4 occurring in the fall and winter. Vadose zone temperatures and subsurface CO2 concentrations revealed a correlation between contaminant respiration and temperature. A time lag of 5 to 7 mo between peak subsurface CO2 concentrations and peak surface efflux is consistent with travel-time estimates for subsurface gas migration. Periods of frozen soils coincided with depressed surface CO2 effluxes and elevated CO2 concentrations, pointing to the temporary presence of an ice layer that inhibited gas transport. Quantitative reactive transport simulations demonstrated aspects of the conceptual model developed from field measurements. Overall, results indicated that source-zone natural attenuation (SZNA) rates and gas transport processes varied seasonally and that the average annual SZNA rate estimated from periodic surface efflux measurements is 60% lower than rates determined from measurements during the summer.

Chromium(VI) generation in vadose zone soils and alluvial sediments of the southwestern Sacramento Valley, California: A potential source of geogenic Cr(VI) to groundwater

International Nuclear Information System (INIS)

Mills, Christopher T.; Morrison, Jean M.; Goldhaber, Martin B.; Ellefsen, Karl J.

2011-01-01

�g kg -1 , representing a minute fraction of total Cr. Chromium(VI) content was typically below detection in surface soils (top 10 cm) where soil organic matter was high, and increased with increasing depth in the soil auger cores as organic matter decreased. Maximum concentrations of Cr(VI) were up to 3 times greater in the deeper drill core samples than the shallow auger cores. Although Cr(VI) in these vadose zone soils and sediments was only a very small fraction of the total solid phase Cr, they are a potentially important source for Cr(VI) to groundwater. Enhanced groundwater recharge through the vadose zone due to irrigation could carry Cr(VI) from the vadose zone to the groundwater and may be the mechanism responsible for the correlation observed between elevated Cr(VI) and NO 3 - concentrations in previously published data for valley groundwaters. Incubation of a valley subsoil showed a Cr(VI) production rate of 24 μg kg -1 a -1 suggesting that field Cr(VI) concentrations could be regenerated annually. Increased Cr(VI) production rates in H + -amended soil incubations indicate that soil acidification processes such as nitrification of ammonium in fertilizers could potentially increase the occurrence of geogenic Cr(VI) in groundwater. Thus, despite the natural origin of the Cr, Cr(VI) generation in the Sacramento Valley soils and sediments has the potential to be influenced by human activities.

Chromium(VI) generation in vadose zone soils and alluvial sediments of the southwestern Sacramento Valley, California: A potential source of geogenic Cr(VI) to groundwater

Energy Technology Data Exchange (ETDEWEB)

Mills, Christopher T., E-mail: cmills@usgs.gov [United States Geological Survey, Crustal Geophysics and Geochemistry Science Center, Denver Federal Center, MS 964D, Denver, CO 80225 (United States); Morrison, Jean M.; Goldhaber, Martin B.; Ellefsen, Karl J. [United States Geological Survey, Crustal Geophysics and Geochemistry Science Center, Denver Federal Center, MS 964D, Denver, CO 80225 (United States)

2011-08-15

from 0 to 42 {mu}g kg{sup -1}, representing a minute fraction of total Cr. Chromium(VI) content was typically below detection in surface soils (top 10 cm) where soil organic matter was high, and increased with increasing depth in the soil auger cores as organic matter decreased. Maximum concentrations of Cr(VI) were up to 3 times greater in the deeper drill core samples than the shallow auger cores. Although Cr(VI) in these vadose zone soils and sediments was only a very small fraction of the total solid phase Cr, they are a potentially important source for Cr(VI) to groundwater. Enhanced groundwater recharge through the vadose zone due to irrigation could carry Cr(VI) from the vadose zone to the groundwater and may be the mechanism responsible for the correlation observed between elevated Cr(VI) and NO{sub 3}{sup -} concentrations in previously published data for valley groundwaters. Incubation of a valley subsoil showed a Cr(VI) production rate of 24 {mu}g kg{sup -1} a{sup -1} suggesting that field Cr(VI) concentrations could be regenerated annually. Increased Cr(VI) production rates in H{sup +}-amended soil incubations indicate that soil acidification processes such as nitrification of ammonium in fertilizers could potentially increase the occurrence of geogenic Cr(VI) in groundwater. Thus, despite the natural origin of the Cr, Cr(VI) generation in the Sacramento Valley soils and sediments has the potential to be influenced by human activities.

Parallel inversion of a massive ERT data set to characterize deep vadose zone contamination beneath former nuclear waste infiltration galleries at the Hanford Site B-Complex (Invited)

Science.gov (United States)

Johnson, T.; Rucker, D. F.; Wellman, D.

2013-12-01

The Hanford Site, located in south-central Washington, USA, originated in the early 1940's as part of the Manhattan Project and produced plutonium used to build the United States nuclear weapons stockpile. In accordance with accepted industrial practice of that time, a substantial portion of relatively low-activity liquid radioactive waste was disposed of by direct discharge to either surface soil or into near-surface infiltration galleries such as cribs and trenches. This practice was supported by early investigations beginning in the 1940s, including studies by Geological Survey (USGS) experts, whose investigations found vadose zone soils at the site suitable for retaining radionuclides to the extent necessary to protect workers and members of the general public based on the standards of that time. That general disposal practice has long since been discontinued, and the US Department of Energy (USDOE) is now investigating residual contamination at former infiltration galleries as part of its overall environmental management and remediation program. Most of the liquid wastes released into the subsurface were highly ionic and electrically conductive, and therefore present an excellent target for imaging by Electrical Resistivity Tomography (ERT) within the low-conductivity sands and gravels comprising Hanford's vadose zone. In 2006, USDOE commissioned a large scale surface ERT survey to characterize vadose zone contamination beneath the Hanford Site B-Complex, which contained 8 infiltration trenches, 12 cribs, and one tile field. The ERT data were collected in a pole-pole configuration with 18 north-south trending lines, and 18 east-west trending lines ranging from 417m to 816m in length. The final data set consisted of 208,411 measurements collected on 4859 electrodes, covering an area of 600m x 600m. Given the computational demands of inverting this massive data set as a whole, the data were initially inverted in parts with a shared memory inversion code, which

Recommendations for computer code selection of a flow and transport code to be used in undisturbed vadose zone calculations for TWRS immobilized wastes environmental analyses

International Nuclear Information System (INIS)

VOOGD, J.A.

1999-01-01

An analysis of three software proposals is performed to recommend a computer code for immobilized low activity waste flow and transport modeling. The document uses criteria restablished in HNF-1839, ''Computer Code Selection Criteria for Flow and Transport Codes to be Used in Undisturbed Vadose Zone Calculation for TWRS Environmental Analyses'' as the basis for this analysis

A hybrid hydrologic-geophysical inverse technique for the assessment and monitoring of leachates in the vadose zone. 1997 annual progress report

International Nuclear Information System (INIS)

Alumbaugh, D.L.

1997-01-01

'It is the objective of this proposed study to develop and field test a new, integrated Hybrid Hydrologic-Geophysical Inverse Technique (HHGIT) for characterization of the vadose zone at contaminated sites. This fundamentally new approach to site characterization and monitoring will provide detailed knowledge about hydrological properties, geological heterogeneity and the extent and movement of contamination. HHGIT combines electrical resistivity tomography (ERT) to geophysically sense a 3D volume, statistical information about fabric of geological formations, and sparse data on moisture and contaminant distributions. Combining these three types of information into a single inversion process will provide much better estimates of spatially varied hydraulic properties and three-dimensional contaminant distributions than could be obtained from interpreting the data types individually. Furthermore, HHGIT will be a geostatistically based estimation technique; the estimates represent conditional mean hydraulic property fields and contaminant distributions. Thus, this method will also quantify the uncertainty of the estimates as well as the estimates themselves. The knowledge of this uncertainty is necessary to determine the likelihood of success of remediation efforts and the risk posed by hazardous materials. Controlled field experiments will be conducted to provide critical data sets for evaluation of these methodologies, for better understanding of mechanisms controlling contaminant movement in the vadose zone, and for evaluation of the HHGIT method as a long term monitoring strategy.'

Computer code selection criteria for flow and transport code(s) to be used in undisturbed vadose zone calculations for TWRS environmental analyses

International Nuclear Information System (INIS)

Mann, F.M.

1998-01-01

The Tank Waste Remediation System (TWRS) is responsible for the safe storage, retrieval, and disposal of waste currently being held in 177 underground tanks at the Hanford Site. In order to successfully carry out its mission, TWRS must perform environmental analyses describing the consequences of tank contents leaking from tanks and associated facilities during the storage, retrieval, or closure periods and immobilized low-activity tank waste contaminants leaving disposal facilities. Because of the large size of the facilities and the great depth of the dry zone (known as the vadose zone) underneath the facilities, sophisticated computer codes are needed to model the transport of the tank contents or contaminants. This document presents the code selection criteria for those vadose zone analyses (a subset of the above analyses) where the hydraulic properties of the vadose zone are constant in time the geochemical behavior of the contaminant-soil interaction can be described by simple models, and the geologic or engineered structures are complicated enough to require a two-or three dimensional model. Thus, simple analyses would not need to use the fairly sophisticated codes which would meet the selection criteria in this document. Similarly, those analyses which involve complex chemical modeling (such as those analyses involving large tank leaks or those analyses involving the modeling of contaminant release from glass waste forms) are excluded. The analyses covered here are those where the movement of contaminants can be relatively simply calculated from the moisture flow. These code selection criteria are based on the information from the low-level waste programs of the US Department of Energy (DOE) and of the US Nuclear Regulatory Commission as well as experience gained in the DOE Complex in applying these criteria. Appendix table A-1 provides a comparison between the criteria in these documents and those used here. This document does not define the models (that

Implementation of Solute Transport in the Vadose Zone into the `HYDRUS Package for MODFLOW'

Science.gov (United States)

Simunek, J.; Beegum, S.; Szymkiewicz, A.; Sudheer, K. P.

2017-12-01

The 'HYDRUS package for MODFLOW' was developed by Seo et al. (2007) and Twarakavi et al. (2008) to simultaneously evaluate transient water flow in both unsaturated and saturated zones. The package, which is based on the HYDRUS-1D model (Šimůnek et al., 2016) simulating unsaturated water flow in the vadose zone, was incorporated into MODFLOW (Harbaugh et al., 2000) simulating saturated groundwater flow. The HYDRUS package in the coupled model can be used to represent the effects of various unsaturated zone processes, including infiltration, evaporation, root water uptake, capillary rise, and recharge in homogeneous or layered soil profiles. The coupled model is effective in addressing spatially-variable saturated-unsaturated hydrological processes at the regional scale, allowing for complex layering in the unsaturated zone, spatially and temporarily variable water fluxes at the soil surface and in the root zone, and with alternating recharge and discharge fluxes (Twarakavi et al., 2008). One of the major limitations of the coupled model was that it could not be used to simulate at the same time solute transport. However, solute transport is highly dependent on water table fluctuations due to temporal and spatial variations in groundwater recharge. This is an important concern when the coupled model is used for analyzing groundwater contamination due to transport through the unsaturated zone. The objective of this study is to integrate the solute transport model (the solute transport part of HYDRUS-1D for the unsaturated zone and MT3DMS (Zheng and Wang, 1999; Zheng, 2009) for the saturated zone) into an existing coupled water flow model. The unsaturated zone component of the coupled model can consider solute transport involving many biogeochemical processes and reactions, including first-order degradation, volatilization, linear or nonlinear sorption, one-site kinetic sorption, two-site sorption, and two-kinetic sites sorption (Šimůnek and van Genuchten, 2008

T Tank Farm Interim Surface Barrier Demonstration--Vadose Zone Monitoring Plan

International Nuclear Information System (INIS)

Zhang, Z. F.; Keller, Jason M.; Strickland, Christopher E.

2007-01-01

The Hanford Site has 149 underground single-shell tanks that store hazardous radioactive waste. Many of these tanks and their associated infrastructure (e.g., pipelines, diversion boxes) have leaked. Some of the leaked waste has entered the groundwater. The largest known leak occurred from the T-106 Tank in 1973. Many of the contaminants from that leak still reside within the vadose zone beneath the T Tank Farm. CH2M Hill Hanford Group, Inc. seeks to minimize movement of this residual contaminant plume by placing an interim barrier on the surface. Such a barrier is expected to prevent infiltrating water from reaching the plume and moving it further. A plan has been prepared to monitor and determine the effectiveness of the interim surface barrier. Soil water content and water pressure will be monitored using off-the-shelf equipment that can be installed by the hydraulic hammer technique. In fiscal year 2006, two instrument nests were installed. Each instrument nest contains a neutron probe access tube, a capacitance probe, four heat-dissipation units, and a drain gauge to measure soil water flux. A meteorological station has been installed outside of the fence. In fiscal year 2007, two additional instrument nests are planned to be installed beneath the proposed barrier.

Estimating fate and transport of multiple contaminants in the vadose zone using a multi-layered soil column and three-phase equilibrium partitioning model

International Nuclear Information System (INIS)

Rucker, Gregory G.

2007-01-01

Soils at waste sites must be evaluated for the potential of residual soil contamination to leach and migrate to the groundwater beneath the disposal area. If migration to the aquifer occurs, contaminants can travel vast distances and pollute drinking water wells, thus exposing human receptors to harmful levels of toxins and carcinogens. To prevent groundwater contamination, a contaminant fate and transport analysis is necessary to assess the migration potential of residual soil contaminants. This type of migration analysis is usually performed using a vadose zone model to account for complex geotechnical and chemical variables including: decay processes, infiltration rate, soil properties, vadose zone thickness, and chemical behavior. The distinct advantage of using a complex model is that less restrictive, but still protective, soil threshold levels may be determined avoiding the unnecessary and costly remediation of marginally contaminated soils. However, the disadvantage of such modeling is the additional cost for data collection and labor required to apply these models. In order to allay these higher costs and to achieve a less restrictive but still protective clean-up level, a multiple contaminant and multi layered soil column equilibrium partitioning model was developed which is faster, simpler and less expensive to use. (authors)

An analytical model for predicting transport in a coupled vadose/phreatic system

International Nuclear Information System (INIS)

Tomasko, D.

1997-05-01

A simple analytical model is presented for predicting the transport of a contaminant in both the unsaturated (vadose) and saturated (phreatic) zones following a surficial spill. The model incorporates advection, dispersion, adsorption, and first-order decay in both zones and couples the transport processes at the water table. The governing equation is solved by using the method of Laplace transforms, with numerical inversion of the Laplace space equation for concentration. Because of the complexity of the functional form for the Laplace space solution, a numerical methodology using the real and imaginary parts of a Fourier series was implemented. To reduce conservatism in the model, dilution at the water table was also included. Verification of the model is demonstrated by its ability to reproduce the source history at the surface and to replicate appropriate one-dimensional transport through either the vadose or phreatic zone. Because of its simplicity and lack of detailed input data requirements, the model is recommended for scoping calculations

Borehole project - Final report of phase 3

International Nuclear Information System (INIS)

Pusch, R.; Ramqvist, G.

2008-03-01

The report describes borehole plugging techniques for use in deep boreholes extending from the ground surface, and construction and placement of plugs in holes of different lengths and orientations bored from the repository rooms. The principle employed is the one proposed in earlier phases of the project, i.e. to tightly seal those parts of boreholes where the rock has few fractures and a low hydraulic conductivity, and filling of those parts that intersect water-bearing fracture zones with physically stable material that does not need to be low-permeable. Four methods for tight plugging have been identified and tested and a technique has been found for filling boreholes that are intersected by fracture zones. The upper end of boreholes extending from the ground surface needs a 'mechanical' seal for which copper metal and concrete work well. The experience from plugging of a 550 m deep borehole at Olkiluoto (OL-KR24) has been compiled and plans worked out for sampling and testing of contacting clay and concrete in this hole and in short holes in the Aespoe URL. (orig.)

Electrical resistivity tomography at the DOE Hanford site

International Nuclear Information System (INIS)

Narbutovskih, S.M.; Halter, T.D.; Sweeney, M.D.; Daily, W.; Ramirez, A.L.

1996-01-01

Recent work at the DOE Hanford site has established the potential of applying Electrical Resistivity Tomography (ERT) for early leak detection under hazardous waste storage facilities. Several studies have been concluded to test the capabilities and limitations of ERT for two different applications. First, field experiments have been conducted to determine the utility of ERT to detect and map leaks from underground storage tanks during waste removal processes. Second, the use of ERT for long term vadose zone monitoring has been tested under different field conditions of depth, installation design, acquisition mode/equipment and infiltration chemistry. This work involves transferring the technology from Lawrence Livermore National Laboratory (LLNL) to the Resource Conservation and Recovery Act (RCRA) program at the DOE Hanford Site. This paper covers field training studies relevant to the second application for long term vadose zone monitoring. Electrical resistivity tomography is a cross-borehole, imaging technique for mapping subsurface resistivity variations. Electrodes are placed at predetermined depths in an array of boreholes. Electrical current is introduced into one electrode pair located in one borehole while the resulting voltage change is detected between electrode pairs in other boreholes similar to a surface dipole-dipole array. These data are tomographically inverted to image temporal resistivity contrasts associated with an infiltration event. Thus a dynamic plume is spatially mapped as a function of time. As a long-term vadose zone monitoring method, different field conditions and performance requirements exist than those for short term tank leak detection. To test ERT under these conditions, two vertical electrode arrays were constructed to a depth of 160 feet with a linear surface array between boreholes

Local fluid flow and borehole strain in the South Iceland Seismic Zone

Science.gov (United States)

Jónsson, S.; Segall, P.; Ágústsson, K.; Agnew, D.

2003-12-01

Installation of 175 borehole strainmeters is planned for PBO. It is therefore vital to understand the behavior of existing strainmeter installations. We investigate signals recorded by three borehole dilatometers in the south Iceland seismic zone following two Mw6.5 earthquakes in June 2000. Poroelastic relaxation has been documented following these events based on InSAR and water level data [Jónsson et al., 2003, Nature]. According to poroelastic theory for a homogeneous isotropic (unfractured) medium, the anticipated post-seismic volumetric strain has the same sign as the coseismic strain step. For example, coseismic compression results in pore-pressure increases; post-earthquake fluid drainage causes additional compression. However, we find that observed strain changes vary considerably between different instruments after the earthquakes. One instrument (HEL) behaves as expected with transient strain increasing with the same sign as the coseismic strain step. Another instrument (SAU) shows partial strain relaxation, opposite in sign to the coseismic signal. The third (BUR) exhibits complete strain relaxation by 3-4 days after the earthquakes (i.e., BUR does not record any permanent strain). BUR has responded in the same fashion to three different earthquakes and two volcanic eruptions, demonstrating conclusively that the transient response is due to processes local to the borehole. Fluid drainage from cracks can explain these observations. Rapid straining results in compression (extension) of the rock and strainmeter. Fluid filled fractures near the borehole transmit normal stress, due to the relative incompressibility of water. Thus, at short time scales the instrument records a coseismic strain step. With time, however, fluid flows out of (in to) the fractures, and the normal stress transmitted across the fractures decreases (increases). As the stress relaxes the strainmeter expands (contracts), reversing the coseismic strain. Barometric responses are

Noise Configuration and fault zone anisotropy investigation from Taiwan Chelungpu-fault Deep Borehole Array

Science.gov (United States)

Hung, R. J.; Ma, K. F.; Song, T. R. A.; Nishida, K.; Lin, Y. Y.

2016-12-01

The Taiwan Chelungpu-fault Drilling Project was operated to understand the fault zone characteristics associated with the 1999 Chichi earthquake. Seven Borehole Seismometers (TCDPBHS) were installed through the identified fault zone to monitor the micro-seismic activities, as well as the fault-zone seismic structure properties. To understand the fault zone anisotropy and its possible temporal variations after the Chichi earthquake, we calculated cross-correlations of the noise at different stations to obtain cross correlation functions (CCFs) of the ambient noise field between every pair of the stations. The result shows that TCDP well site suffers from complex wavefield, and phase traveltime from CCF can't provide explicit result to determine the dominated wavefield. We first analyze the power density spectra and probability density functions of this array. We observe that the spectra show diurnal variation in the frequency band 1-25 Hz, suggesting human-generated sources are dominated in this frequency band. Then, we focus on the particle motion analysis at each CCF. We assume one component at a station plays as a visual source and compute the CCF tensor in other station components. The particle motion traces show high linearity which indicate that the dominated wavefield in our study area is body wave signals with the azimuth approximate to 60° from north. We also analyze the Fourier spectral amplitudes by rotating every 5 degrees in time domain to search for the maximum background energy distribution. The result shows that the spectral amplitudes are stronger at NE-SW direction, with shallow incident angles which are comparable with the CCF particle motion measurement. In order to obtain higher resolution about the dominated wavefield in our study area, we also used beamforming from surface station array to validate our results from CCF analysis. In addition to the CCF analysis to provide the noise configuration at the TCDPBHS site for further analysis on

CO2 leakage monitoring and analysis to understand the variation of CO2 concentration in vadose zone by natural effects

Science.gov (United States)

Joun, Won-Tak; Ha, Seung-Wook; Kim, Hyun Jung; Ju, YeoJin; Lee, Sung-Sun; Lee, Kang-Kun

2017-04-01

Controlled ex-situ experiments and continuous CO2 monitoring in the field are significant implications for detecting and monitoring potential leakage from CO2 sequestration reservoir. However, it is difficult to understand the observed parameters because the natural disturbance will fluctuate the signal of detections in given local system. To identify the original source leaking from sequestration reservoir and to distinguish the camouflaged signal of CO2 concentration, the artificial leakage test was conducted in shallow groundwater environment and long-term monitoring have been performed. The monitoring system included several parameters such as pH, temperature, groundwater level, CO2 gas concentration, wind speed and direction, atmospheric pressure, borehole pressure, and rainfall event etc. Especially in this study, focused on understanding a relationship among the CO2 concentration, wind speed, rainfall and pressure difference. The results represent that changes of CO2 concentration in vadose zone could be influenced by physical parameters and this reason is helpful in identifying the camouflaged signal of CO2 concentrations. The 1-D column laboratory experiment also was conducted to understand the sparking-peak as shown in observed data plot. The results showed a similar peak plot and could consider two assumptions why the sparking-peak was shown. First, the trapped CO2 gas was escaped when the water table was changed. Second, the pressure equivalence between CO2 gas and water was broken when the water table was changed. These field data analysis and laboratory experiment need to advance due to comprehensively quantify local long-term dynamics of the artificial CO2 leaking aquifer. Acknowledgement Financial support was provided by the "R&D Project on Environmental Management of Geologic CO2 Storage" from the KEITI (Project Number: 2014001810003)

VAMOS: The verification and monitoring options study: Current research options for in-situ monitoring and verification of contaminant remediation and containment within the vadose zone

International Nuclear Information System (INIS)

Betsill, J.D.; Gruebel, R.D.

1995-09-01

The Verification and Monitoring Options Study Project (VAMOS) was established to identify high-priority options for future vadose-zone environmental research in the areas of in-situ remediation monitoring, post-closure monitoring, and containment emplacement and verification monitoring. VAMOS examined projected needs not currently being met with applied technology in order to develop viable monitoring and verification research options. The study emphasized a compatible systems approach to reinforce the need for utilizing compatible components to provide user friendly site monitoring systems. To identify the needs and research options related to vadose-zone environmental monitoring and verification, a literature search and expert panel forums were conducted. The search included present drivers for environmental monitoring technology, technology applications, and research efforts. The forums included scientific, academic, industry, and regulatory environmental professionals as well as end users of environmental technology. The experts evaluated current and future monitoring and verification needs, methods for meeting these needs, and viable research options and directions. A variety of high-priority technology development, user facility, and technology guidance research options were developed and presented as an outcome of the literature search and expert panel forums

Results of Tank-Leak Detection Demonstration Using Geophysical Techniques at the Hanford Mock Tank Site-Fiscal Year 2001

International Nuclear Information System (INIS)

Barnett, D BRENT.; Gee, Glendon W.; Sweeney, Mark D.

2002-01-01

During July and August of 2001, Pacific Northwest National Laboratory (PNNL), hosted researchers from Lawrence Livermore and Lawrence Berkeley National laboratories, and a private contractor, HydroGEOPHYSICS, Inc., for deployment of the following five geophysical leak-detection technologies at the Hanford Site Mock Tank in a Tank Leak Detection Demonstration (TLDD): Electrical Resistivity Tomography (ERT); Cross-Borehole Electromagnetic Induction (CEMI) ; High-Resolution Resistivity (HRR); Cross-Borehole Radar (XBR); Cross-Borehole Seismic Tomography (XBS). Under a ''Tri-party Agreement'' with Federal and state regulators, the U.S. Department of Energy will remove wastes from single-shell tanks (SSTs) and other miscellaneous underground tanks for storage in the double-shell tank system. Waste retrieval methods are being considered that use very little, if any, liquid to dislodge, mobilize, and remove the wastes. As additional assurance of protection of the vadose zone beneath the SSTs, tank wastes and tank conditions may be aggressively monitored during retrieval operations by methods that are deployed outside the SSTs in the vadose zone

Test Plan for the Demonstration of Geophysical Techniques for Single-Shell Tank Leak Detection at the Hanford Mock Tank Site: Fiscal Year 2001

Energy Technology Data Exchange (ETDEWEB)

Barnett, D. Brent; Gee, Glendon W.; Sweeney, Mark D.

2001-07-31

As part of the Leak Detection, Monitoring and Mitigation (LDMM) program conducted by CH2M HILL 105-A during FY 2001. These tests are being conducted to assess the applicability of these methods (Electrical Resistance Tomography [ERT], High Resolution Resistivity [HRR], Cross-Borehole Seismography [XBS], Cross-Borehole Radar [XBR], and Cross-Borehole Electromagnetic Induction [CEMI]) to the detection and measurement of Single Shell Tank (SST) leaks into the vadose zone during planned sluicing operations. The testing in FY 2001 will result in the selection of up to two methods for further testing in FY 2002. In parallel with the geophysical tests, a Partitioning Interwell Tracer Test (PITT) study will be conducted simultaneously at the Mock Tank to assess the effectiveness of this technology in detecting and quantifying tank leaks in the vadose zone. Preparatory and background work using Cone Penetrometer methods (CPT) will be conducted at the Mock Tank site and an adjacent test area to derive soil properties for groundtruthing purposes for all methods.

Collecting soil vapor from the Vadose Zone with an instrumented membrane system

International Nuclear Information System (INIS)

Martins, S.A.

1992-07-01

As part of an on-going program to monitor ground water pollution, the SEAMIST instrumented membrane system was purchased and installed in two boreholes at the Lawrence Livermore National Laboratory (LLNL). SEAMIST is a flexible, removable, polyvinylchloride-coated, nylon membrane tube used to seal the sides of a borehole and to which sampling devices and other types of instrumentation may be attached. This paper describes a method to sample soil vapor (a component of soil gas) with the SEAMIST system from a borehole at several depths simultaneously. The cryotraps used with this technique were tested for their collection efficiency, and those data are presented. Data on the integrity of the SEAMIST borehole seal are also reported

System-Scale Model of Aquifer, Vadose Zone, and River Interactions for the Hanford 300 Area - Application to Uranium Reactive Transport

Energy Technology Data Exchange (ETDEWEB)

Rockhold, Mark L.; Bacon, Diana H.; Freedman, Vicky L.; Parker, Kyle R.; Waichler, Scott R.; Williams, Mark D.

2013-10-01

This report represents a synthesis and integration of basic and applied research into a system-scale model of the Hanford 300 Area groundwater uranium plume, supported by the U.S. Department of Energy’s Richland Operations (DOE-RL) office. The report integrates research findings and data from DOE Office of Science (DOE-SC), Office of Environmental Management (DOE-EM), and DOE-RL projects, and from the site remediation and closure contractor, Washington Closure Hanford, LLC (WCH). The three-dimensional, system-scale model addresses water flow and reactive transport of uranium for the coupled vadose zone, unconfined aquifer, and Columbia River shoreline of the Hanford 300 Area. The system-scale model of the 300 Area was developed to be a decision-support tool to evaluate processes of the total system affecting the groundwater uranium plume. The model can also be used to address “what if” questions regarding different remediation endpoints, and to assist in design and evaluation of field remediation efforts. For example, the proposed cleanup plan for the Hanford 300 Area includes removal, treatment, and disposal of contaminated sediments from known waste sites, enhanced attenuation of uranium hot spots in the vadose and periodically rewetted zone, and continued monitoring of groundwater with institutional controls. Illustrative simulations of polyphosphate infiltration were performed to demonstrate the ability of the system-scale model to address these types of questions. The use of this model in conjunction with continued field monitoring is expected to provide a rigorous basis for developing operational strategies for field remediation and for defining defensible remediation endpoints.

A borehole instrumentation program for characterization of unsaturated-zone percolation

International Nuclear Information System (INIS)

Kume, J.; Rousseau, J.P.

1994-01-01

A borehole instrumentation and monitoring program has been designed by the US Geological Survey to support site characterization of unsaturated-zone percolation at Yucca Mountain, Nye County, Nevada. This program provides a means of defining the unsaturated-zone fluid flow (liquid and gas) potential field in a setting that incorporates large-scale stratigraphic and structural features, and the influences of geothermal heat flow and atmospheric pressure changes. Data derived from this program will be used to evaluate the suitability of Yucca Mountain as a mined geologic-repository for the storage of high-level, radioactive waste. These data include in-situ temperature, pneumatic pressure, and water potential. In addition, the instrumentation program provides facilities for gas-sampling, gas-tracer diffusion testing, water-injection testing, water-level monitoring, neutron moisture-meter monitoring, temperature profiling, and in-situ recalibration of the downhole sensors. The program included testing and development of: (1) precision sensors for measurement; (2) a downhole instrumentation-station-apparatus to house the sensors, recalibrate sensors in-situ, and allow access to instrument stations for other testing purposes; and (3) surface-based support and instrumentation facilities

Analysis of borehole-radar reflection logs from selected HC boreholes at the Project Shoal area, Churchill County, Nevada

Science.gov (United States)

Lane, J.W.; Joesten, P.K.; Pohll, G.M.; Mihevic, Todd

2001-01-01

Single-hole borehole-radar reflection logs were collected and interpreted in support of a study to characterize ground-water flow and transport at the Project Shoal Area (PSA) in Churchill County, Nevada. Radar logging was conducted in six boreholes using 60-MHz omni-directional electric-dipole antennas and a 60-MHz magnetic-dipole directional receiving antenna.Radar data from five boreholes were interpreted to identify the location, orientation, estimated length, and spatial continuity of planar reflectors present in the logs. The overall quality of the radar data is marginal and ranges from very poor to good. Twenty-seven reflectors were interpreted from the directional radar reflection logs. Although the range of orientation interpreted for the reflectors is large, a significant number of reflectors strike northeast-southwest and east-west to slightly northwest-southeast. Reflectors are moderate to steeply dipping and reflector length ranged from less than 7 m to more than 133 m.Qualitative scores were assigned to each reflector to provide a sense of the spatial continuity of the reflector and the characteristics of the field data relative to an ideal planar reflector (orientation score). The overall orientation scores are low, which reflects the general data quality, but also indicates that the properties of most reflectors depart from the ideal planar case. The low scores are consistent with reflections from fracture zones that contain numerous, closely spaced, sub-parallel fractures.Interpretation of borehole-radar direct-wave velocity and amplitude logs identified several characteristics of the logged boreholes: (1) low-velocity zones correlate with decreased direct-wave amplitude, indicating the presence of fracture zones; (2) direct-wave amplitude increases with depth in three of the boreholes, suggesting an increase in electrical resistivity with depth resulting from changes in mineral assemblage or from a decrease in the specific conductance of ground

Interpretation of chemical and isotopic data from boreholes in the unsaturated zone at Yucca Mountain, Nevada

International Nuclear Information System (INIS)

Yang, I.C.; Rattray, G.W.; Yu, P.

1996-01-01

Analyses of pore water from boreholes at Yucca Mountain indicate that unsaturated-zone pore water has significantly larger concentrations of chloride and dissolved solids than the saturated-zone water or perched-water bodies. Chemical compositions are of the calcium sulfate or calcium chloride types in the Paintbrush Group (Tiva Canyon, Yucca Mountain, Pah Canyon, and bedded tuffs), and sodium carbonate or bicarbonate type water in the Calico Hills Formation. Tritium profiles from boreholes at Yucca Mountain indicate tritium-concentration inversions (larger tritium concentrations are located below the smaller tritium concentration in a vertical profile) occur in many places. These inversions indicate preferential flow through fractures. Rock-gas compositions are similar to that of atmospheric air except that carbon dioxide concentrations are generally larger than those in the air. The delta carbon-13 values of gas are fairly constant from surface to 365.8 meters, indicating little interaction between the gas CO 2 and caliche in the soil. Model calculations indicate that the gas transport in the unsaturated zone at Yucca Mountain agrees well with the gas-diffusion process. Tritium-modeling results indicate that the high tritium value of about 100 tritium units in the Calico Hills Formation of UZ-16 is within limits of a piston-flow model with a water residence time of 32 to 35 years. The large variations in tritium concentrations with narrow peaks imply piston flow or preferential fracture flow rather than matrix flow. In reality, the aqueous-phase flow in the unsaturated zone is between piston and well-mixed flows but is closer to a piston flow

Vapor Intrusion Estimation Tool for Unsaturated Zone Contaminant Sources. User’s Guide

Science.gov (United States)

2016-08-30

estimation process when applying the tool. The tool described here is focused on vapor-phase diffusion from the current vadose zone source , and is not...from the current defined vadose zone source ). The estimated soil gas contaminant concentration obtained from the pre-modeled scenarios for a building...need a full site-specific numerical model to assess the impacts beyond the current vadose zone source . 35 5.0 References Brennan, R.A., N

Long-term pumping test in borehole KR24 flow measurements

Energy Technology Data Exchange (ETDEWEB)

Rouhiainen, P.; Poellaenen, J. [PRG-Tec Oy, Espoo (Finland)

2005-09-15

The Difference Flow method can be used for the relatively fast determination of transmissivity and hydraulic head in fractures or fractured zones in cored boreholes. In this study, the Difference Flow method was used for hydraulic crosshole interference tests. The tests were performed in boreholes KR24 (pumped borehole) KR4, KR7, KR8, KRlO, KR14, KR22, KR22B, KR26, KR27, KR27B, KR28 and KR28B at Olkiluoto during the first and second quarters of 2004. The distance between the boreholes varies from approximately tens of meters to hundreds of meters. All the measurements were carried out in open boreholes, i.e. no packers were used. For interpretation, a normal single hole test was first performed in each borehole. Flow rates and drawdown were first measured both without pumping and with pumping the borehole under test. For practical reasons, the data set is neither complete nor similar in all tested boreholes. Connected flow to borehole KR24 was detected in all these boreholes. These flow responses were concentrated on a few zones. (orig.)

Analysis of borehole-radar reflection logs from selected HC boreholes at the Project Shoal area, Churchill County, Nevada; TOPICAL

International Nuclear Information System (INIS)

Lane, J.W. Jr.; Joesten, P.K.; Pohll, Greg; Mihevic, Todd

2001-01-01

Single-hole borehole-radar reflection logs were collected and interpreted in support of a study to characterize ground-water flow and transport at the Project Shoal Area (PSA) in Churchill County, Nevada. Radar logging was conducted in six boreholes using 60-MHz omni-directional electric-dipole antennas and a 60-MHz magnetic-dipole directional receiving antenna. Radar data from five boreholes were interpreted to identify the location, orientation, estimated length, and spatial continuity of planar reflectors present in the logs. The overall quality of the radar data is marginal and ranges from very poor to good. Twenty-seven reflectors were interpreted from the directional radar reflection logs. Although the range of orientation interpreted for the reflectors is large, a significant number of reflectors strike northeast-southwest and east-west to slightly northwest-southeast. Reflectors are moderate to steeply dipping and reflector length ranged from less than 7 m to more than 133 m. Qualitative scores were assigned to each reflector to provide a sense of the spatial continuity of the reflector and the characteristics of the field data relative to an ideal planar reflector (orientation score). The overall orientation scores are low, which reflects the general data quality, but also indicates that the properties of most reflectors depart from the ideal planar case. The low scores are consistent with reflections from fracture zones that contain numerous, closely spaced, sub-parallel fractures. Interpretation of borehole-radar direct-wave velocity and amplitude logs identified several characteristics of the logged boreholes: (1) low-velocity zones correlate with decreased direct-wave amplitude, indicating the presence of fracture zones; (2) direct-wave amplitude increases with depth in three of the boreholes, suggesting an increase in electrical resistivity with depth resulting from changes in mineral assemblage or from a decrease in the specific conductance of ground

Experimental Plan: 300 Area Treatability Test: In Situ Treatment of the Vadose Zone and Smear Zone Uranium Contamination by Polyphosphate Infiltration

International Nuclear Information System (INIS)

Wellman, Dawn M.; Pierce, Eric M.; Oostrom, Mart; Fruchter, Jonathan S.

2007-01-01

The overall objectives of the treatability test is to evaluate and optimize polyphosphate remediation technology for infiltration either from ground surface, or some depth of excavation, providing direct stabilization of uranium within the deep vadose and capillary fringe above the 300 Area aquifer. Expected result from this experimental plan is a data package that includes: (1) quantification of the retardation of polyphosphate, (2) the rate of degradation and the retardation of degradation products as a function of water content, (3) an understanding of the mechanism of autunite formation via the reaction of solid phase calcite-bound uranium and aqueous polyphosphate remediation technology, (4) an understanding of the transformation mechanism, identity of secondary phases, and the kinetics of the reaction between uranyl-carbonate and silicate minerals with the polyphosphate remedy under solubility-limiting conditions, (5) quantification of the extent and rate of uranium released and immobilized based on the infiltration rate of the polyphosphate remedy and the effect of and periodic wet-dry cycling on the efficacy of polyphosphate remediation for uranium in the vadose zone and capillary fringe, and (6) quantification of reliable equilibrium solubility values for autunite under hydraulically unsaturated conditions allowing accurate prediction of the long-term stability of autunite. Moreover, results of intermediate scale testing will quantify the transport of polyphosphate and degradation products, and yield degradation rates, at a scale that is bridging the gap between the small-scale UFA studies and the field scale. These results will be used to test and verify a site-specific, variable saturation, reactive transport model and to aid in the design of a pilot-scale field test of this technology. In particular, the infiltration approach and monitoring strategy of the pilot test would be primarily based on results from intermediate-scale testing. Results from this

New experiences in borehole dilution techniques

International Nuclear Information System (INIS)

Umesh Chandra

1977-01-01

A study of filtration rate and direction of groundwater flow was made at various depths in borehole using bromine-82 as groundwater tracer. The filtration rates were found to vary along the depth of borehole. Vertical flow in the borehole was observed in an alluvial aquifer even after sealing the borehole by rubber packers. The filtration rates, obtained without the packer at various depths, were much less than those obtained with packer. Microscopic hydrological information was obtained around the borehole which was useful in planning a drainage system in the area. A depth was located in the borehole where vertical flow was in opposite directions. At another depth a zone of horizontal flow was observed where vertical flow was in opposite directions. The improved instrumentation used rendered the field work extremely easy quick and readily reproducible. (author)

Evaluating the role of soil variability on groundwater pollution and recharge at regional scale by integrating a process-based vadose zone model in a stochastic approach

Science.gov (United States)

Coppola, Antonio; Comegna, Alessandro; Dragonetti, Giovanna; Lamaddalena, Nicola; Zdruli, Pandi

2013-04-01

Interpreting and predicting the evolution of water resources and soils at regional scale are continuing challenges for natural scientists. Examples include non-point source (NPS) pollution of soil and surface and subsurface water from agricultural chemicals and pathogens, as well as overexploitation of groundwater resources. The presence and build up of NPS pollutants may be harmful for both soil and groundwater resources. The accumulation of salts and trace elements in soils can significantly impact crop productivity, while loading of salts, nitrates, trace elements and pesticides into groundwater supplies can deteriorate a source of drinking and irrigation water. Consequently, predicting the spatial distribution and fate of NPS pollutants in soils at applicative scales is now considered crucial for maintaining the fragile balance between crop productivity and the negative environmental impacts of NPS pollutants, which is a basis of sustainable agriculture. Soil scientists and hydrologists are regularly asked to assist state agencies to understand these critical environmental issues. The most frequent inquiries are related to the development of mathematical models needed for analyzing the impacts of alternative land-use and best management use and management of soil and water resources. Different modelling solutions exist, mainly differing on the role of the vadose zone and its horizontal and vertical variability in the predictive models. The vadose zone (the region from the soil surface to the groundwater surface) is a complex physical, chemical and biological ecosystem that controls the passage of NPS pollutants from the soil surface where they have been deposited or accumulated due to agricultural activities, to groundwater. Physically based distributed hydrological models require the internal variability of the vadose zone be explored at a variety of scales. The equations describing fluxes and storage of water and solutes in the unsaturated zone used in these

Room Q data report: Test borehole data from April 1989 through November 1991

International Nuclear Information System (INIS)

Jensen, A.L.; Howard, C.L.; Jones, R.L.; Peterson, T.P.

1993-03-01

Pore-pressure and fluid-flow tests were performed in 15 boreholes drilled into the bedded evaporites of the Salado Formation from within the Waste Isolation Pilot Plant (WIPP). The tests measured fluid flow and pore pressure within the Salado. The boreholes were drilled into the previously undisturbed host rock around a proposed cylindrical test room, Room Q, located on the west side of the facility about 655 m below ground surface. The boreholes were about 23 m deep and ranged over 27.5 m of stratigraphy. They were completed and instrumented before excavation of Room Q. Tests were conducted in isolated zones at the end of each borehole. Three groups of 5 isolated zones extend above, below, and to the north of Room Q at increasing distances from the room axis. Measurements recorded before, during, and after the mining of the circular test room provided data about borehole closure, pressure, temperature, and brine seepage into the isolated zones. The effects of the circular excavation were recorded. This data report presents the data collected from the borehole test zones between April 25, 1989 and November 25, 1991. The report also describes test development, test equipment, and borehole drilling operations

Characterization of Vadose Zone Sediments from C Waste Management Area: Investigation of the C-152 Transfer Line Leak

Energy Technology Data Exchange (ETDEWEB)

Brown, Christopher F; Serne, R JEFFREY; Bjornstad, Bruce N; Valenta, Michelle M; Lanigan, David C; Vickerman, Tanya S; Clayton, Ray E; Geiszler, Keith N; Iovin, Cristian; Clayton, Eric T; Kutynakov, I V; Baum, Steven R; Lindberg, Michael J; Orr, Robert D

2007-02-05

A geologic/geochemical investigation in the vicinity of UPR-200-E-82 was performed using pairs of cone-penetrometer probe holes. A total of 41 direct-push cone-penetrometer borings (19 pairs to investigate different high moisture zones in the same sampling location and 3 individual) were advanced to characterize vadose zone moisture and the distribution of contaminants. A total of twenty sample sets, containing up to two split-spoon liners and one grab sample, were delivered to the laboratory for characterization and analysis. The samples were collected around the documented location of the C-152 pipeline leak, and created an approximately 120-ft diameter circle around the waste site. UPR-200-E-82 was a loss of approximately 2,600 gallons of Cs-137 Recovery Process feed solution containing an estimated 11,300 Ci of cesium-137 and 5 Ci of technetium-99. Several key parameters that are used to identify subsurface contamination were measured, including: water extract pH, electrical conductivity, nitrate, technetium-99, sodium, and uranium concentrations and technetium-99 and uranium concentrations in acid extracts. All of the parameters, with the exception of electrical conductivity, were elevated in at least some of the samples analyzed as part of this study. Specifically, soil pH was elevated (from 8.69 to 9.99) in five samples collected northeast and southwest of the C-152 pipeline leak. Similarly, samples collected from these same cone-pentrometer holes contained significantly more water-extractable sodium (more than 50 g/g of dry sediment), uranium (as much as 7.66E-01 g/g of dry sediment), nitrate (up to 30 g/g of dry sediment), and technetium-99 (up to 3.34 pCi/g of dry sediment). Most of the samples containing elevated concentrations of water-extractable sodium also had decreased levels of water extractable calcium and or magnesium, indicating that tank-related fluids that were high in sodium did seep into the vadose zone near these probe holes. Several of the

Results of Tank-Leak Detection Demonstration Using Geophysical Techniques at the Hanford Mock Tank Site-Fiscal Year 2001

Energy Technology Data Exchange (ETDEWEB)

Barnett, D BRENT.; Gee, Glendon W.; Sweeney, Mark D.

2002-03-01

During July and August of 2001, Pacific Northwest National Laboratory (PNNL), hosted researchers from Lawrence Livermore and Lawrence Berkeley National laboratories, and a private contractor, HydroGEOPHYSICS, Inc., for deployment of the following five geophysical leak-detection technologies at the Hanford Site Mock Tank in a Tank Leak Detection Demonstration (TLDD): (1) Electrical Resistivity Tomography (ERT); (2) Cross-Borehole Electromagnetic Induction (CEMI); (3) High-Resolution Resistivity (HRR); (4) Cross-Borehole Radar (XBR); and (5) Cross-Borehole Seismic Tomography (XBS). Under a ''Tri-party Agreement'' with Federal and state regulators, the U.S. Department of Energy will remove wastes from single-shell tanks (SSTs) and other miscellaneous underground tanks for storage in the double-shell tank system. Waste retrieval methods are being considered that use very little, if any, liquid to dislodge, mobilize, and remove the wastes. As additional assurance of protection of the vadose zone beneath the SSTs, tank wastes and tank conditions may be aggressively monitored during retrieval operations by methods that are deployed outside the SSTs in the vadose zone.

Sediment Properties: E-Area Completion Project

Energy Technology Data Exchange (ETDEWEB)

Millings, M.; Bagwell, L.; Amidon, M.; Dixon, K.

2011-04-29

Characterization and Analysis Penetrometer System (SCAPS) cone penetrometer test (CPT) truck at ECP plots 6, 7, 8 and 9 to collect inferred lithology data for the vadose zone. Results from this study are used to make recommendations for future modeling efforts involving the ECP plots. The conceptual model of the ECP hydrogeology differs from the conceptual model of the current ELLWF disposal area in that for the ECP plots, the topography (ground surface) is generally lower in elevation; The Upland and top of Tobacco Road lithostratigraphic units are missing (eroded); The water table occurs lower in elevation (i.e., it occurs in lower stratigraphic units); and the Tan Clay Confining Zone (TCCZ) often occurs within the vadose zone (rather than in the saturated zone). Due to the difference in the hydrogeology between the current ELLWF location and the ECP plots, different vadose zone properties are recommended for the ECP plots versus the properties recommended by Phifer et al. (2006) for the current disposal units. Results from this study do not invalidate or conflict with the current PA's use of the Upper and Lower Vadose Zone properties as described by Phifer et al. (2006) for the current ELLWF disposal units. The following modeling recommendations are made for future modeling of the ECP plots where vadose zone properties are required: (1) If a single vadose zone property is preferred, the properties described by Phifer et al. (2006) for the Upper Vadose Zone encompass the general physical properties of the combined sands and clays in the ECP vadose zone sediments despite the differences in hydrostratigraphic units. (2) If a dual zone system is preferred, a combination of the Lower Zone properties and the Clay properties described by Phifer et al. (2006) are appropriate for modeling the physical properties of the ECP vadose zone. The Clay properties would be assigned to the Tan Clay Confining Zone (TCCZ) and any other significant clay layers, while the Lower Zone properties

Current challenges in quantifying preferential flow through the vadose zone

Science.gov (United States)

Koestel, John; Larsbo, Mats; Jarvis, Nick

2017-04-01

In this presentation, we give an overview of current challenges in quantifying preferential flow through the vadose zone. A review of the literature suggests that current generation models do not fully reflect the present state of process understanding and empirical knowledge of preferential flow. We believe that the development of improved models will be stimulated by the increasingly widespread application of novel imaging technologies as well as future advances in computational power and numerical techniques. One of the main challenges in this respect is to bridge the large gap between the scales at which preferential flow occurs (pore to Darcy scales) and the scale of interest for management (fields, catchments, regions). Studies at the pore scale are being supported by the development of 3-D non-invasive imaging and numerical simulation techniques. These studies are leading to a better understanding of how macropore network topology and initial/boundary conditions control key state variables like matric potential and thus the strength of preferential flow. Extrapolation of this knowledge to larger scales would require support from theoretical frameworks such as key concepts from percolation and network theory, since we lack measurement technologies to quantify macropore networks at these large scales. Linked hydro-geophysical measurement techniques that produce highly spatially and temporally resolved data enable investigation of the larger-scale heterogeneities that can generate preferential flow patterns at pedon, hillslope and field scales. At larger regional and global scales, improved methods of data-mining and analyses of large datasets (machine learning) may help in parameterizing models as well as lead to new insights into the relationships between soil susceptibility to preferential flow and site attributes (climate, land uses, soil types).

Use of Gas Transported Reactants for Uranium Remediation in Vadose Zone Sediments

International Nuclear Information System (INIS)

Szecsody, James E.; Zhong, Lirong; Truex, Michael J.; Resch, Charles T.; Williams, Mark D.

2010-01-01

This laboratory-scale investigation is focused on decreasing mobility of uranium in subsurface contaminated sediments in the vadose zone by in situ geochemical manipulation at low water content. This geochemical manipulation of the sediment surface phases included reduction, pH change (acidic and alkaline), and additions of chemicals (phosphate, ferric iron) to form specific precipitates. Reactants were advected into 1-D columns packed with Hanford 200 area U-contaminated sediment as a reactive gas (for CO2, NH3, H2S, SO2), with a 0.1% water content mist (for NaOH, Fe(III), HCl, PO4) and with a 1% water content foam (for PO4). Because uranium is present in the sediment in multiple phases, changes in U surface phases were evaluated with a series of liquid extractions that dissolve progressively less soluble phases and electron microbe identification of mineral phases. In terms of the short-term decrease in U mobility (in decreasing order), NH3, NaOH mist, CO2, HCl mist, and Fe(III) mist showed 20% to 35% change in U surface phases. The two reductive gas treatments (H2S and SO2) showed little change. For long-term decrease in U transport, mineral phases created that had low solubility (phosphates, silicates) were desired, so NH3, phosphates (mist and foam delivered), and NaOH mist showed the greatest formation of these minerals.

Summary of Uranium Solubility Studies in Concrete Waste Forms and Vadose Zone Environments

Energy Technology Data Exchange (ETDEWEB)

Golovich, Elizabeth C.; Wellman, Dawn M.; Serne, R. Jeffrey; Bovaird, Chase C.

2011-09-30

One of the methods being considered for safely disposing of Category 3 low-level radioactive wastes is to encase the waste in concrete. Concrete encasement would contain and isolate the waste packages from the hydrologic environment and act as an intrusion barrier. The current plan for waste isolation consists of stacking low-level waste packages on a trench floor, surrounding the stacks with reinforced steel, and encasing these packages in concrete. These concrete-encased waste stacks are expected to vary in size with maximum dimensions of 6.4 m long, 2.7 m wide, and 4 m high. The waste stacks are expected to have a surrounding minimum thickness of 15 cm of concrete encasement. These concrete-encased waste packages are expected to withstand environmental exposure (solar radiation, temperature variations, and precipitation) until an interim soil cover or permanent closure cover is installed and to remain largely intact thereafter. Any failure of concrete encasement may result in water intrusion and consequent mobilization of radionuclides from the waste packages. This report presents the results of investigations elucidating the uranium mineral phases controlling the long-term fate of uranium within concrete waste forms and the solubility of these phases in concrete pore waters and alkaline, circum-neutral vadose zone environments.

Borehole Breakout Growth and In-Situ Stress Orientation in the Central Scandinavian Caledonides: Results from the Cosc-1 Borehole

Science.gov (United States)

Wenning, Q.; Zappone, A.; Berthet, T.; Ask, M. V. S.; Rosberg, J. E.; Almqvist, B. S. G.

2017-12-01

Borehole breakouts are often assumed to form near instantaneously due to stress perturbations around boreholes after the rock mass was removed. Recent observations in sediments [e.g., Moore et al., 2011] and crystalline rocks [e.g., Berard and Cornet, 2003], as well as numerical modelling results [e.g., Schoenball et al., 2014], suggest that there are cases in which borehole breakout grows radially over time, forcing us to reconsider subsurface stress estimation. These observations are rare due to drilling difficulties (i.e., cementing and casing the borehole after drilling), often only allowing a single image logging campaign. In 2014, the Collisional Orogeny in the Scandinavian Caledonides deep scientific borehole (COSC-1) was drilled to a depth of 2.5 km. To date the borehole is open and uncased, allowing two acoustic televiewer logging campaigns, with more than one year between campaigns. The borehole is still available for supplementary data collactions. These logs provide detailed images along the full length of the 2.5 km deep borehole with 1.6 km of overlapping logs for breakout and drilling induced tensile fracture analysis. The results show from the sparse occurrence of breakouts and drilling induced tensile fractures a NW-SE average maximum horizontal stress direction, consistent with the general trend in Scandinavia. The unique acquisition of image logs in two successions allows for analysis of time-dependent borehole deformation, indicating that six breakout zones have crept, both along the borehole axis and radially (up to 20° growth) around the borehole. While some breakouts have grown, the formation of new breakouts has not occurred. The occurrence of breakouts and their growth appear to be independent of lithology. The observed growth after the second logging campaign suggests that under conditions where the stress exceeded the strength of the rock, the resulting breakout causes perturbations in the stresses around the borehole in the near

Geophysical borehole logging test procedure: Final draft

International Nuclear Information System (INIS)

1986-09-01

The purpose of geophysical borehole logging from the At-Depth Facility (ADF) is to provide information which will assist in characterizing the site geologic conditions and in classifying the engineering characteristics of the rock mass in the vicinity of the ADF. The direct goals of borehole logging include identification of lithologic units and their correlation from hole to hole, identification of fractured or otherwise porous or permeable zones, quantitative or semi-quantitative estimation of various formation properties, and evaluation of factors such as the borehole diameter and orientation. 11 figs., 4 tabs

The experimental results and analysis of a borehole radar prototype

International Nuclear Information System (INIS)

Liu, Sixin; Wu, Junjun; Dong, Hang; Fu, Lei; Wang, Fei

2012-01-01

A prototype of borehole radar has been successfully tested in three sites for different purposes under a field condition. The objective of the prototype is providing an effective down-hole tool for detecting targets in deep boreholes situated in a relatively high conductivity area such as the metal ores. The first testing site is at a geothermal field. The fractures extending more than 20 m from the borehole are delineated by the borehole radar in the single-hole reflection mode. The second testing site is located in a jade mine for basement evaluation. The cross-hole measurement mode was used to detect the cavities made by previous unorganized mining activities. Several high-velocity anomalies were found in the velocity profile and presumably the targets of the mine shafts and tunnels. The third test site is located in a mineralized belt characterized by low resistivity less than 1000 Ohm m, the surface-borehole measurement was carried out and the data were processed with velocity tomography. The low-velocity zone corresponds to a mineralized zone from geological records. The three testing results proved the readiness of this borehole radar prototype for further deployment in more complicated and realistic field situations. (paper)

Waste storage in the vadose zone affected by water vapor condensation and leaching

International Nuclear Information System (INIS)

Cary, J.W.; Gee, G.W.; Whyatt, G.A.

1990-08-01

One of the major concerns associated with waste storage in the vadose zone is that toxic materials may somehow be leached and transported by advecting water down to the water table and reach the accessible environment through either a well or discharge to a river. Consequently, care is taken to provide barriers over and around the storage sites to reduce contact between infiltrating water and the buried waste form. In some cases, it is important to consider the intrusion of water vapor as well as water in the liquid phase. Water vapor diffuses through porous material along vapor pressure gradients. A slightly low temperature, or the presence of water-soluble components in the waste, favors water condensation resulting in leaching of the waste form and advection of water-soluble components to the water table. A simple analysis is presented that allows one to estimate the rate of vapor condensation as a function of waste composition and backfill materials. An example using a waste form surrounded by concrete and gravel layers is presented. The use of thermal gradients to offset condensation effects of water-soluble components in the waste form is discussed. Thermal gradients may be controlled by design factors that alter the atmospheric energy exchange across the soil surface or that interrupt the geothermal heat field. 7 refs., 2 figs., 1 tab

Site characterization and validation - monitoring of saline tracer transport by borehole radar measurements

International Nuclear Information System (INIS)

Olsson, O.; Andersson, P.; Gustafsson, E.

1991-08-01

The objective of this experiment was to map tracer transport in fractured crystalline rock through a combination of radar difference tomography and measurements of tracer concentration in boreholes and the validation drift. The experiment was performed twice, first the D-boreholes were used as a sink and then they were replaced by the validation drift and the experiment repeated. In both experiments saline tracer (200 ml/min, 2% salinity) was injected into fracture zone H about 25 m from the validation drift. The experiment revealed an inhomogeneous transmissivity distribution in Zone H. A significant portion of the tracer is transported upwards along Zone H and towards boreholes T1, T2, and W1. The breakthrough data from both experiments indicate that there are two major transport paths from borehole C2 to the D-boreholes/validation drift. One slow and diluted path to the bottom of the drift which carries the bulk of the mass and one fast path to the crown of the drift with high tracer concentration. The radar difference tomograms show that some tracer is lost through Zone S which intersects Zone H and is nearly perpendicular to it. The intersection between the two zones seems to constitute a preferred flow path. The breakthrough data and the radar difference tomograms have also been used to estimate flow porosity. The estimate obtained area of the same order approximately 10 -4 . (au) (28 refs.)

Geomechanical Considerations for the Deep Borehole Field Test

Science.gov (United States)

Park, B. Y.

2015-12-01

Deep borehole disposal of high-level radioactive waste is under consideration as a potential alternative to shallower mined repositories. The disposal concept consists of drilling a borehole into crystalline basement rocks to a depth of 5 km, emplacement of canisters containing solid waste in the lower 2 km, and plugging and sealing the upper 3 km of the borehole. Crystalline rocks such as granites are particularly attractive for borehole emplacement because of their low permeability and porosity at depth, and high mechanical strength to resist borehole deformation. In addition, high overburden pressures contribute to sealing of some of the fractures that provide transport pathways. We present geomechanical considerations during construction (e.g., borehole breakouts, disturbed rock zone development, and creep closure), relevant to both the smaller-diameter characterization borehole (8.5") and the larger-diameter field test borehole (17"). Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

Crosshole investigations - results from borehole radar investigations

International Nuclear Information System (INIS)

Olsson, O.; Falk, L.; Sandberg, E.; Forslund, O.; Lundmark, L.

1987-05-01

A new borehole radar system has been designed, built and tested. The system consists of borehole transmitter and receiver probes, a signal control unit for communication with the borehole probes, and a computer unit for storage and display of data. The system can be used both in singlehole and crosshole modes and probing ranges of 115 m and 300 m, respectively, have been obtained at Stripa. The borehole radar is a short pulse system which uses center frequencies in the range 20 to 60 MHz. Single hole reflection measurements have been used to identify fracture zones and to determine their position and orientation. The travel time and amplitude of the first arrival measured in a crosshole experiment can be used as input data in a tomographic analysis. (orig./DG)

Electrical resistivity tomography at the DOE Hanford site

International Nuclear Information System (INIS)

Narbutovskih, S.M.

1996-01-01

Recent work at the DOE Hanford site has established the potential of applying Electrical Resistivity Tomography (ERT) for early leak detection under hazardous waste storage facilities. Several studies have been concluded to test the capabilities and limitations of ERT for two different applications. First, field experiments have been conducted to determine the utility of ERT to detect and map leaks from underground storage tanks during waste removal processes. Second, the use of ERT for long term vadose zone monitoring has been tested under different field conditions of depth, installation design, acquisition mode/equipment and infiltration chemistry. This work involves transferring the technology from Lawrence Livermore National Laboratory (LLNL) to the Resource Conservation and Recovery Act (RCRA) program at the DOE Hanford Site. This paper covers field training studies relevant to the second application for long term vadose monitoring. Electrical resistivity tomography is a cross-borehole, imaging technique for mapping subsurface resistivity variations. Electrodes are placed at predetermined depths in an array of boreholes. Electrical current is introduced into one electrode pair located in one borehole while the resulting voltage change is detected between electrode pairs in other boreholes similar to a surface dipole-dipole array. These data are topographically inverted to image temporal resistivity contrasts associated with an infiltration event. Thus a dynamic plume is spatially mapped as a function of time. As a long-term vadose zone monitoring method, different field conditions and performance requirements exist than those for short term tank leak detection. To test ERT under these conditions, two vertical electrode arrays were constructed to a depth of 160 feet with a linear surface array between boreholes. The fielding was used to facilitate the technology transfer from LLNL to the Hanford RCRA program. Installation methods, commercial equipment and

Characterization of Direct-Push Vadose Zone Sediments from the 241-B and 241-BX Tank Farms

International Nuclear Information System (INIS)

Brown, Christopher F.; Icenhower, Jonathan P.; Um, Wooyong; Bjornstad, Bruce N.; Valenta, Michelle M.; Iovin, Cristian; Lanigan, David C.; Clayton, Ray E.; Geiszler, Keith N.; Clayton, Eric T.; Kutnyakov, Igor V.; Baum, Steven R.; Lindberg, Michael J.; Orr, Robert D.

2007-01-01

Geochemical tests provide evidence for the transit of a plume of caustic waste solution through the sediment column at the Hanford 241-B and -BX Tank Farms. Direct-push samples recovered from boreholes surrounding Tanks 241-B-110 and 241-BX-102 and related waste transfer lines and diversion boxes included sediments typical of those previously recovered from other localities on the Hanford Site. The Hanford formation sediments are dominantly quartzo-feldspathic sands strewn with lithic fragments, displaying a range of particle size distributions and sorting characteristics. Some moderately well-sorted, fine-grained lithologies are interpreted as lenticular bodies irregularly dispersed in coarser-grained, more poorly sorted sediments. Tier I tests conducted on the vadose zone sediments revealed an inverse correlation between moisture content and sediment size fraction (i.e., there is greater moisture content in finer-grained sediments). The Tier I tests also showed that the pore water solutions were likely sodium-rich, moderately saline, and possessed higher pH values than background (untainted) sediments. These data are characteristic of sediments that have encountered sodium-rich, saline, caustic waste solution, as documented in other reports at other suspect contamination sites around Hanford. Analyses of solutions from 1:1 water extracts reveal relatively balanced cation and anion concentrations, indicating that most of the geochemical species have been accounted for. The water extract data for affected sediments also indicate unusually high concentrations of aluminum, iron, and phosphorus. The relatively high concentrations of aluminum and iron may be the result of dissolution of secondary amorphous phases that precipitated after a reactive plume partially dissolved aluminum- and iron-bearing phases as it migrated through the sediment column. On the other hand, the presence of elevated concentrations of phosphorous may be the tell-tale signature of wastes

Characterization of Direct-Push Vadose Zone Sediments from the 241-B and 241-BX Tank Farms

Energy Technology Data Exchange (ETDEWEB)

Brown, Christopher F.; Icenhower, Jonathan P.; Um, Wooyong; Bjornstad, Bruce N.; Valenta, Michelle M.; Iovin, Cristian; Lanigan, David C.; Clayton, Ray E.; Geiszler, Keith N.; Clayton, Eric T.; Kutnyakov, Igor V.; Baum, Steven R.; Lindberg, Michael J.; Orr, Robert D.

2007-12-21

Geochemical tests provide evidence for the transit of a plume of caustic waste solution through the sediment column at the Hanford 241-B and -BX Tank Farms. Direct-push samples recovered from boreholes surrounding Tanks 241-B-110 and 241-BX-102 and related waste transfer lines and diversion boxes included sediments typical of those previously recovered from other localities on the Hanford Site. The Hanford formation sediments are dominantly quartzo-feldspathic sands strewn with lithic fragments, displaying a range of particle size distributions and sorting characteristics. Some moderately well-sorted, fine-grained lithologies are interpreted as lenticular bodies irregularly dispersed in coarser-grained, more poorly sorted sediments. Tier I tests conducted on the vadose zone sediments revealed an inverse correlation between moisture content and sediment size fraction (i.e., there is greater moisture content in finer-grained sediments). The Tier I tests also showed that the pore water solutions were likely sodium-rich, moderately saline, and possessed higher pH values than background (untainted) sediments. These data are characteristic of sediments that have encountered sodium-rich, saline, caustic waste solution, as documented in other reports at other suspect contamination sites around Hanford. Analyses of solutions from 1:1 water extracts reveal relatively balanced cation and anion concentrations, indicating that most of the geochemical species have been accounted for. The water extract data for affected sediments also indicate unusually high concentrations of aluminum, iron, and phosphorus. The relatively high concentrations of aluminum and iron may be the result of dissolution of secondary amorphous phases that precipitated after a reactive plume partially dissolved aluminum- and iron-bearing phases as it migrated through the sediment column. On the other hand, the presence of elevated concentrations of phosphorous may be the tell-tale signature of wastes

Appraisal of nuclear waste isolation in the vadose zone in arid and semiarid regions (with emphasis on the Nevada Test Site)

International Nuclear Information System (INIS)

Wollenberg, H.A.; Wang, J.S.Y.; Korbin, G.

1983-05-01

An appraisal was made of the concept of isolating high-level radioactive waste in the vadose zone of alluvial-filled valleys and tuffaceous rocks of the Basin and Range geomorphic province. Principal attributes of these terranes are: (1) low population density, (2) low moisture influx, (3) a deep water table, (4) the presence of sorptive rocks, and (5) relative ease of construction. Concerns about heat effects of waste on unsaturated rocks of relatively low thermal conductivity are considered. Calculations show that a standard 2000-acre repository with a thermal loading of 40 kW/acre in partially saturated alluvium or tuff would experience an average temperature rise of less than 100 0 C above the initial temperature. The actual maximum temperature would depend strongly on the emplacement geometry. Concerns about seismicity, volcanism, and future climatic change are also mitigated. The conclusion reached in this appraisal is that unsaturated zones in alluvium and tuff of arid regions should be investigated as comprehensively as other geologic settings considered to be potential repository sites

Appraisal of nuclear waste isolation in the vadose zone in arid and semiarid regions (with emphasis on the Nevada Test Site)

Energy Technology Data Exchange (ETDEWEB)

Wollenberg, H.A.; Wang, J.S.Y.; Korbin, G.

1983-05-01

An appraisal was made of the concept of isolating high-level radioactive waste in the vadose zone of alluvial-filled valleys and tuffaceous rocks of the Basin and Range geomorphic province. Principal attributes of these terranes are: (1) low population density, (2) low moisture influx, (3) a deep water table, (4) the presence of sorptive rocks, and (5) relative ease of construction. Concerns about heat effects of waste on unsaturated rocks of relatively low thermal conductivity are considered. Calculations show that a standard 2000-acre repository with a thermal loading of 40 kW/acre in partially saturated alluvium or tuff would experience an average temperature rise of less than 100{sup 0}C above the initial temperature. The actual maximum temperature would depend strongly on the emplacement geometry. Concerns about seismicity, volcanism, and future climatic change are also mitigated. The conclusion reached in this appraisal is that unsaturated zones in alluvium and tuff of arid regions should be investigated as comprehensively as other geologic settings considered to be potential repository sites.

Clay mineralogy of selected borehole sediments from the Lawrence Livermore National Laboratory and Sandia National Laboratories, Livermore, California

International Nuclear Information System (INIS)

Smith, D.K.; Peifer, D.W.; Rood, C.K.

1992-04-01

Smectite, 90 to 100% interstratified illite-smectite, chlorate, and kaolinite are identified in boreholes drilled in fluvial and alluvial fan deposits of the Plio-Pleistocene Livermore Formation in the vicinity of Lawrence Livermore National Laboratory (LLNL) and Sandia National Laboratories (SNL), Livermore. X-ray diffraction, scanning electron microscopy, and electron microprobe studies indicate the clays persist through 150 ft of gravels, sands, silts, and mudstones of the vadose zone to total drilling depths of 200 ft in the saturated zone. Scanning electron microscopy indicates that true clays (layer silicate only) comprise between 2 and 15 modal percent of the Livermore Formation. Authigenic and detrital smectite, 90% interlayered illite-smectite, and chlorate persist throughout the stratigraphic section; kaolinite occurs only in the upper 100 ft of the section and is absent below. Smectite comprises between 60 to 90% of the true (layer silicate only) clay fraction. Illite and kaolinite±chlorite abundances fluctuate between 10 to 30% and 10 to 20% of this fraction, respectively. Authigenic smectite, illite, and chlorate crystallize together with detrital phases; the authigenic component increases with depth. The relative percentages of clay minerals define unique mineralogical intervals, which can be correlated between boreholes. Pervasive microfractures and interconnected porosity are inherent in the finer sediments; the microfractures typically are 1 mm or less in width and are variably spaced. Voids and microfractures are conspicuously lined by clays. Porosity for the argillaceous sediments ranges between 23 and 40%; Brunauer, Emmett, and Teller (BET) specific surface area decreases variably from 40 m 2 /g near the surface to 15 m 2 /g at the 115-ft depth. Within the pelitic matrix, iron, iron-titanium, chromium, and manganese oxides are pervasive

SITE CHARACTERIZATION AND MONITORING DATA FROM THE AREA 5 PILOT WELLS

International Nuclear Information System (INIS)

2005-01-01

Three exploratory boreholes were drilled and completed to the uppermost alluvial aquifer in Area 5 of the Nevada Test Site, Nye County, Nevada, in 1992. The boreholes and associated investigations were part of the Area 5 Site Characterization Program developed to meet data needs associated with regulatory requirements applicable to the disposal of low-level, mixed, and high-specific-activity waste at this site. This series of boreholes was specifically designed to characterize the hydrogeology of the thick vadose zone and to help define the water quality and hydraulic properties of the uppermost aquifer. Wells UE5PW-1, UE5PW-2, and UE5PW-3 are located in a triangular array near the southeast, northeast, and northwest corners, respectively, of the approximately 2.6-square-kilometer Area 5 Radioactive Waste Management Site to give reasonable spatial coverage for sampling and characterization, and to help define the nearly horizontal water table. Two of the wells, UE5PW-1 and UE5PW-2, penetrated only unconsolidated alluvial materials. The third well, located closer to the margin of the basin, penetrated both alluvium and underlying ash-flow and bedded tuff units. The watertable was encountered at the elevation of approximately 734 meters. The results of laboratory testing of core and drill cuttings samples indicate that the mineralogical, material, and hydrologic properties of the alluvium are very similar within and between boreholes. Additional tests on the same core and drill cuttings samples indicate that hydrologic conditions within the alluvium are also similar between pilot wells. Both core and drill cuttings samples are dry (less than 10 percent water content by weight) throughout the entire unsaturated section of alluvium, and water content increases slightly with depth in each borehole. Water potential measurements on core samples show a large positive potential gradient (water tends to move upward, rather than downward) to a depth of approximately 30

Feasibility of the Shallow High Resolution Seismic Reflection Technique for Use at the Hanford Site

International Nuclear Information System (INIS)

S.M., Narbutovskih.

1993-01-01

Data obtained during site characterization should be useful to assess the need for remediation, to evaluate and design effective remedial plans, and to allow long-term monitoring to discern remediation effectiveness. A valuable environmental tool that incorporates this data is a model that describes groundwater and vadose zone flow and transport characteristics. Data on geology and hydrology combined with information on contaminant sources are incorporated into these conceptual models that delineate the relative significance of the various fluid migration pathways. Downstream these same models also support risk assessment, remediation design, and long-term assessment of remediation effectiveness. Consequently, the building of coherent, accurate vadose zone and groundwater models is fundamental to a successful remediation. Among the important requirements for these models is accurate knowledge of flow domain boundaries and soil characteristics. At the Hanford Site, this knowledge is obtained primarily from borehole data, which provides information only at a point. In the high energy flood and fluvial deposits found at the Hanford Site, it can, at times, be difficult to correlate lithologic horizons between boreholes. Where there is no borehole control, our understanding of the geometry of hydrogeologic boundaries and thus of fluid migration paths is limited. Surface geophysical techniques are generally used to provide a measure of geologic control between boreholes. In particular, the seismic reflection method has the potential to provide the greatest resolution of the subsurface hydrogeology between and beyond boreholes

Hydraulic effects of unsealed boreholes. Numerical groundwater flow modelling of the Forsmark and Laxemar sites

International Nuclear Information System (INIS)

Bockgaard, Niclas

2011-06-01

The objective of the work was to investigate hydraulic effects of open and poorly sealed boreholes on groundwater flow conditions through simulations using a numerical groundwater model. Specifically, the boreholes KFM07A, KFM09A, and KFM09B in Forsmark and the boreholes KLX04, KLX06, and KLX10 in Laxemar were studied. The criteria for the selection of these boreholes were that the boreholes should represent typical conditions of the site, the borehole length should exceed 500 m, and that several major fractured zones should be intersected. The boreholes KFM07A and KLX06, respectively, were selected as reference boreholes for more detailed studies of different sealing schemes. The model setup of the Forsmark model followed the Forsmark 2.2 regional-scale conceptual hydrogeological model. The model domain was approximately 15 km (north-south) x 10 km (west- east) x 1.2 km (depth). The 131 deformation zones and three layers of superficial horizontal sheet joint were modelled deterministically. A stochastic discrete fracture network (DFN) representing fractures and minor deformation zones were also generated between the deterministic deformation zones inside central model volume. The side lengths of the square fractures were from 1,000 m down to 10 m. In order to resolve the details of flow in to and out from the borehole, a more detailed DFN was generated in a zone around the borehole KFM07A, where fractures down to a side length of 0.5 m were considered. The model setup of the Laxemar model followed the SDM-Site Laxemar (Laxemar 2.3) regional scale conceptual hydrogeological model. The model domain was approximately 12 km (north-south) x 20 km (west-east) x 2.1 km (depth). A number of 71 deformation zones were modelled deterministically, and one realization of a stochastic DFN, the so-called hydrogeological DFN model base case, was imported to the model. Similar to the Forsmark case, a more detailed DFN was also generated around the reference borehole KLX06. The

Hydraulic effects of unsealed boreholes. Numerical groundwater flow modelling of the Forsmark and Laxemar sites

Energy Technology Data Exchange (ETDEWEB)

Bockgaard, Niclas [Golder Associates AB, Stockholm (Sweden)

2011-06-15

The objective of the work was to investigate hydraulic effects of open and poorly sealed boreholes on groundwater flow conditions through simulations using a numerical groundwater model. Specifically, the boreholes KFM07A, KFM09A, and KFM09B in Forsmark and the boreholes KLX04, KLX06, and KLX10 in Laxemar were studied. The criteria for the selection of these boreholes were that the boreholes should represent typical conditions of the site, the borehole length should exceed 500 m, and that several major fractured zones should be intersected. The boreholes KFM07A and KLX06, respectively, were selected as reference boreholes for more detailed studies of different sealing schemes. The model setup of the Forsmark model followed the Forsmark 2.2 regional-scale conceptual hydrogeological model. The model domain was approximately 15 km (north-south) x 10 km (west- east) x 1.2 km (depth). The 131 deformation zones and three layers of superficial horizontal sheet joint were modelled deterministically. A stochastic discrete fracture network (DFN) representing fractures and minor deformation zones were also generated between the deterministic deformation zones inside central model volume. The side lengths of the square fractures were from 1,000 m down to 10 m. In order to resolve the details of flow in to and out from the borehole, a more detailed DFN was generated in a zone around the borehole KFM07A, where fractures down to a side length of 0.5 m were considered. The model setup of the Laxemar model followed the SDM-Site Laxemar (Laxemar 2.3) regional scale conceptual hydrogeological model. The model domain was approximately 12 km (north-south) x 20 km (west-east) x 2.1 km (depth). A number of 71 deformation zones were modelled deterministically, and one realization of a stochastic DFN, the so-called hydrogeological DFN model base case, was imported to the model. Similar to the Forsmark case, a more detailed DFN was also generated around the reference borehole KLX06. The

Assessment of geophysical logs from borehole USW G-2, Yucca Mountain, Nevada

International Nuclear Information System (INIS)

Nelson, P.H.; Schimschal, U.

1993-01-01

Commercial logging contractors, Western Atlas, Schlumberger, and Edcon obtained borehole geophysical logs at the site of a potential high level nuclear waste repository at Yucca Mountain, Nevada. Drill hole USW-G2 was picked for this test of suitable logging tools and logging technology, both representing state-of-the-art technology by these commercial companies. Experience gained by analysis of existing core data and a variety of logs obtained earlier by Birdwell and Dresser Atlas served as a guide to a choice of logs to be obtained. Logs were obtained in water-filled borehole in zeolitized tuff (saturated zone) and in air-filled borehole largely in unaltered welded tuff (unsaturated zone)

Utilization of test boreholes in prospecting and mining operations

International Nuclear Information System (INIS)

Sierak, J.P.

1987-01-01

Test boreholes are of fundamental importance for mining and prospecting operations. The drilling techniques are suited to the geological conditions and to the nature of the information desired. At Cogema, non-coring test boreholes, mainly drilled by a rotary percussive method, represent over 90% of the footage drilled; they achieve impressive performances at a cost which is by far less than that of coring test boreholes. The geological exploitation of these test boreholes is effected by a combined investigation of well logging and of cuttings. These investigations lead to an assessment for certain substances like uranium or coal or they mark the limits for favourable zones which alone will form the object of coring boreholes. In mining operations, boreholes indicate the definition for workable panels; they ensure at less cost the distribution of fluids, the forwarding of stowing material and the mine ventilation [fr

Cost effectiveness analysis of the SEAMIST trademark membrane system technology

International Nuclear Information System (INIS)

Henriksen, A.D.; Booth, S.R.

1993-01-01

This report describes the cost and performance characteristics of SEAMIST trademark, an innovative technology that facilitates measurements of contaminants in both vertical and horizontal vadose zone boreholes. This new technology consists of an airtight membrane linear that is pneumatically emplaced inside the borehole structure. Sampling ports with attached tubing, absorbent collectors, or various in situ measuring devices can be fabricated into the linear and used for monitoring volatile organic compounds (VOCs), semivolatile organic compounds (SVOCs), pesticides, herbicides, polynuclear aromatic hydrocarbons, polychlorinated biphenyls, or radioactive substances. In addition, small instruments can be guided through the lined borehole and measurements taken inside at specified intervals

Assessing toxic levels of hydrocarbons on microbial degrader communities in vadose zone fill soils

International Nuclear Information System (INIS)

Schoenberg, T.H.; Long, S.C.

1995-01-01

Authentic fill samples were collected from the vadose zone at a highway travel plaza. The contamination at the site is a combination of gasoline, diesel, and waste oil resulting from leaking underground storage tanks. Microbial assessments including plate counts and specific-degrader enumerations were performed to establish the presence of degrader microbial communities, and thus bioremediation potential. Contaminant levels were estimated in samples by quantifying headspace VOCs in collection jars. Physical soil characteristics including soil grain size distribution and moisture content were measured to evaluate the potential ecological variables that would affect implementation of a bioremediation technology. Toxicity screening using the Microtox trademark acute toxicity assay was used to compare the level of toxicity present among samples. These analyses were used to assess the potential for using in situ bioventing remediation to clean-up the leaking underground storage tank spill study site. High contaminant levels appear to have exerted a toxic effect and resulted in smaller total microbial community sizes in highly contaminated areas (thousands of ppmv) of the site. Microtox trademark EC50 results generally corroborated with the trends of the enumeration experiments. Microbial characterization results indicate that in situ bioremediation would be possible at the study site. Soil heterogeneity appears to pose the greatest challenges to the design and implementation of bioremediation at this site

Vadose-zone instrumentation in coarse alluvial deposits of the Amargosa Desert near Beatty, Nevada

International Nuclear Information System (INIS)

Morgan, D.S.; Fischer, J.M.

1984-01-01

A vadose-zone monitoring shaft near Beatty, NV, is 1.52 m in diameter and penetrates nearly 14 m of unsaturated fluvial sediments. These sediments are comprised of silty sand, coarse sandy gravel, and poorly cemented sand, with gravel and occasional cobbles and boulders. Thirty-three lateral ports at 11 levels between 3 and 13 m deep allow access to undisturbed sediments outside the vertical shaft. The prefabricated metal shaft was emplaced in a 2.44-m-diameter hole excavated by using a crane drill with bucket and flight augers. Laboratory-calibrated thermocouple-psychrometers are being used to measure soil-matrix potential. A method of installing the phychrometers was developed which will allow their retrieval, after extended periods in the soil, for cleaning, recalibration, and reinstallation. Primary access holes 2.5 cm in diameter are drilled laterally outward from the monitoring shaft to a distance of approximately 4 m. The psychrometer is then inserted into the primary access hole and sealed into a smaller diameter boring in the undisturbed material at the outer end of the primary access hole. Data are collected and stored by a programmable measurement-control and data-logger system powered by photovoltaic cells. Magnetic-tape data storage is used to back up daily data retrieval via telecommunication with the project headquarters in Carson City, Nev., 520 km north of the study

Poly-use multi-level sampling system for soil-gas transport analysis in the vadose zone.

Science.gov (United States)

Nauer, Philipp A; Chiri, Eleonora; Schroth, Martin H

2013-10-01

Soil-gas turnover is important in the global cycling of greenhouse gases. The analysis of soil-gas profiles provides quantitative information on below-ground turnover and fluxes. We developed a poly-use multi-level sampling system (PMLS) for soil-gas sampling, water-content and temperature measurement with high depth resolution and minimal soil disturbance. It is based on perforated access tubes (ATs) permanently installed in the soil. A multi-level sampler allows extraction of soil-gas samples from 20 locations within 1 m depth, while a capacitance probe is used to measure volumetric water contents. During idle times, the ATs are sealed and can be equipped with temperature sensors. Proof-of-concept experiments in a field lysimeter showed good agreement of soil-gas samples and water-content measurements compared with conventional techniques, while a successfully performed gas-tracer test demonstrated the feasibility of the PMLS to determine soil-gas diffusion coefficients in situ. A field application of the PMLS to quantify oxidation of atmospheric CH4 in a field lysimeter and in the forefield of a receding glacier yielded activity coefficients and soil-atmosphere fluxes well in agreement with previous studies. With numerous options for customization, the presented tool extends the methodological choices to investigate soil-gas transport in the vadose zone.

Characterization of contaminant transport by gravity, capilliarity and barometric pumping in heterogeneous vadose regimes. 1997 annual progress report

International Nuclear Information System (INIS)

Carrigan, C.R.

1997-01-01

'Vadose regimes can be the sites of complex interactions between the atmosphere and groundwater. When a volatile contaminant exists as free product or in dissolved form in the vadose environment, upward transport can occur with the contaminant ultimately being vented as a vapor into the atmosphere. This transport happens naturally and can be enhanced by anisotropy resulting from heterogenities in the vadose regime. Several stages in the transport process are involved in going from a volatile, liquid state contaminant to a contaminant vapor vented at the surface. In a three-year effort, called the Vadose Zone Transport Study, the authors are investigating, with the aid of existing data, new field studies involving dissolved tracer gases and 3-D diagnostic computer simulations that provide a framework to interpret the observations, the detailed nature of each of these stages of transport in several different kinds of vadose regimes. They are emphasizing the impact of features specific to a site, that is, the local geology and hydrology, on each stage of the transport process. In particular they want to better understand how the time scales for (1) partitioning contaminants from the liquid to the vapor states and then (2) transporting the vapor out of the vadose regime are dependent on the specific character of a site. Such time-scale information will be important for evaluating the potential of contaminant sources as well as remediation strategies including natural remediation approaches.'

Monitoring percolation of a conductive tracer, as a proxy for nitrate transport, through glacial till and fractured sandstone in the vadose zone underlying a potato field, using 3D cross-hole electrical resistivity imaging

Science.gov (United States)

Wang, S.; Butler, K. E.; Serban, D.; Petersen, B.; Grimmett, M.

2016-12-01

Nitrate is a necessary nutrient for crops, but high surface water and groundwater concentrations can negatively affect aquatic ecosystem and human health. At AAFC-AAC Harrington Research Farm (PEI, Canada), 3D cross-hole electrical resistivity imaging (ERI) is being used to investigate the percolation of a conductive tracer (KCl) through a 17 m thick vadose zone as a proxy for the transport of nitrate under natural recharge conditions. The objectives are to investigate the effect of heterogeneity on transport pathways and infer how long it would take for changes in farming practices at the surface to affect nitrate loading to the underlying aquifer. The resistivity array consists of 96 permanently installed electrodes - 24 at 0.68 m spacing in each of three 16 m deep boreholes arranged in a triangle with 9 m sides, and 24 at 1 m spacing buried in shallow trenches connecting the boreholes. A background survey revealed five sub-horizontal layers of alternating resistivity in general agreement with the geology of 6 m soil and glacial till overburden overlying interbedded sandstone and shaley sandstone layers. On March 27th, 2015, 1.1 m of snow was removed from a 15.2 m2 area positioned symmetrically inside the triangular array and 100 kg of granular KCl was distributed on the ground surface. The removed snow was immediately replaced to await the spring thaw. Post-tracer surveys indicate tracer had percolated to depths of 1 m, 1.2 m, 3.0 m and 3.5 m by the 4th, 26th, 30th, and 46th days after tracer application. Its movement slowed significantly by early May, 2015, with the end of snow melt. Tracer spread laterally very slowly through the summer and early fall, 2015, but has remained within the triangular array. The shallow conductivity anomaly produced by the tracer diminished significantly over the winter and spring of 2016 but showed little evidence of bulk matrix flow below 3.5 m depth. It is speculated that fractures in the glacial till, too thin to be resolved by

A chaotic-dynamical conceptual model to describe fluid flow and contaminant transport in a fractured vadose zone. 1997 progress report and presentations at the annual meeting, Ernest Orlando Lawrence Berkeley National Laboratory, December 3-4, 1997

International Nuclear Information System (INIS)

Faybishenko, B.; Doughty, C.; Geller, J.

1998-07-01

Understanding subsurface flow and transport processes is critical for effective assessment, decision-making, and remediation activities for contaminated sites. However, for fluid flow and contaminant transport through fractured vadose zones, traditional hydrogeological approaches are often found to be inadequate. In this project, the authors examine flow and transport through a fractured vadose zone as a deterministic chaotic dynamical process, and develop a model of it in these terms. Initially, the authors examine separately the geometric model of fractured rock and the flow dynamics model needed to describe chaotic behavior. Ultimately they will put the geometry and flow dynamics together to develop a chaotic-dynamical model of flow and transport in a fractured vadose zone. They investigate water flow and contaminant transport on several scales, ranging from small-scale laboratory experiments in fracture replicas and fractured cores, to field experiments conducted in a single exposed fracture at a basalt outcrop, and finally to a ponded infiltration test using a pond of 7 by 8 m. In the field experiments, they measure the time-variation of water flux, moisture content, and hydraulic head at various locations, as well as the total inflow rate to the subsurface. Such variations reflect the changes in the geometry and physics of water flow that display chaotic behavior, which they try to reconstruct using the data obtained. In the analysis of experimental data, a chaotic model can be used to predict the long-term bounds on fluid flow and transport behavior, known as the attractor of the system, and to examine the limits of short-term predictability within these bounds. This approach is especially well suited to the need for short-term predictions to support remediation decisions and long-term bounding studies. View-graphs from ten presentations made at the annual meeting held December 3--4, 1997 are included in an appendix to this report

Geochemical evolution of highly alkaline and saline tank waste plumes during seepage through vadose zone sediments

International Nuclear Information System (INIS)

Wan, Jiamin; Tokunaga, Tetsu K.; Larsen, Joern T.; Serne, R. JEFFREY

2004-01-01

Leakage of highly saline and alkaline radioactive waste from storage tanks into underlying sediments is a serious environmental problem at the Hanford Site in Washington State. This study focuses on geochemical evolution of tank waste plumes resulting from interactions between the waste solution and sediment. A synthetic tank waste solution was infused into unsaturated Hanford sediment columns (0.2, 0.6, and 2 m) maintained at 70C to simulate the field contamination process. Spatially and temporally resolved geochemical profiles of the waste plume were obtained. Thorough OH neutralization (from an initial pH 14 down to 6.3) was observed. Three broad zones of pore solutions were identified to categorize the dominant geochemical reactions: the silicate dissolution zone (pH > 10), pH-neutralized zone (pH 10 to 6.5), and displaced native sediment pore water (pH 6.5 to 8). Elevated concentrations of Si, Fe, and K in plume fluids and their depleted concentrations in plume sediments reflected dissolution of primary minerals within the silicate dissolution zone. The very high Na concentrations in the waste solution resulted in rapid and complete cation exchange, reflected in high concentrations of Ca and Mg at the plume front. The plume-sediment profiles also showed deposition of hydrated solids and carbonates. Fair correspondence was obtained between these results and analyses of field borehole samples from a waste plume at the Hanford Site. Results of this study provide a well-defined framework for understanding waste plumes in the more complex field setting and for understanding geochemical factors controlling transport of contaminant species carried in waste solutions that leaked from single-shell storage tanks in the past

Fault fracture zone evaluation using borehole geophysical logs; case study at Nojima fault, Awaji island; Kosei butsuri kenso ni yoru danso hasaitai no hyoka

Energy Technology Data Exchange (ETDEWEB)

Ikeda, R; Omura, K [National Research Institute for Disaster Prevention, Tsukuba (Japan); Yamamoto, T [Geophysical Surveying and Consulting Co. Ltd., Tokyo (Japan)

1997-10-22

Ikeda, et al., in their examination of log data obtained from a borehole (2000m deep) drilled at Ashio, Tochigi Prefecture, where micro-earthquakes swarm at very shallow levels, pay special attention to porosity. Using correlationship between the porosity and elastic wave velocity/resistivity, the authors endeavor to find the presence of secondary pores, dimensions of faults, composition of water in strata in faults, and difference in matrix between rocks, all these for the classification and evaluation of fault fracture zones. In the present report, log data from a borehole (1800m deep) drilled to penetrate the Nojima fault (Nojima-Hirabayashi, Awaji island) that emerged during the Great Hanshin-Himeji Earthquake are analyzed in the same way as the above-named Ashio data, and the results are compared with the Ashio results. Immediately below the Nojima-Hirabayashi fault fractured zone, stress is found remarkably reduced and the difference stress quite small in size. This is interpreted as indicating a state in which clay has already developed well in the fault fractured zone ready to allow the occurrence of shear fracture or a state in which such has already occurred for the release of stress. 4 refs., 5 figs.

Fate of trace organic compounds during vadose zone soil treatment in an onsite wastewater system.

Science.gov (United States)

Conn, Kathleen E; Siegrist, Robert L; Barber, Larry B; Meyer, Michael T

2010-02-01

During onsite wastewater treatment, trace organic compounds are often present in the effluents applied to subsurface soils for advanced treatment during vadose zone percolation and groundwater recharge. The fate of the endocrine-disrupting surfactant metabolites 4-nonylphenol (NP), 4-nonylphenolmonoethoxylate (NP1EO), and 4-nonylphenolmonoethoxycarboxylate (NP1EC), metal-chelating agents ethylenediaminetetraacetic acid (EDTA) and nitrilotriacetic acid (NTA), antimicrobial agent triclosan, stimulant caffeine, and antibiotic sulfamethoxazole during transport through an unsaturated sandy loam soil was studied at a field-scale test site. To assess the effects of effluent quality and hydraulic loading rate (HLR) on compound fate in the soil profile, two effluents (septic tank or textile biofilter) were applied at two design HLRs (2 or 8 cm/d). Chemical concentrations were determined in the two effluents and soil pore water at 60, 120, and 240 cm below the soil infiltrative surface. Concentrations of trace organic compounds in septic tank effluent were reduced by more than 90% during transport through 240 cm (often within 60 cm) of soil, likely due to sorption and biotransformation. However, the concentration of NP increased with depth in the shallow soil profile. Additional treatment of anaerobic septic tank effluent with an aerobic textile biofilter reduced effluent concentrations of many compounds, but generally did not affect any changes in pore water concentrations. The soil profile receiving septic tank effluent (vs. textile biofilter effluent) generally had greater percent removal efficiencies. EDTA, NP, NP1EC, and sulfamethoxazole were measured in soil pore water, indicating the ability of some trace organic compounds to reach shallow groundwater. Risk is highly dependent on the degree of further treatment in the saturated zone and the types and proximity of uses for the receiving groundwater environment. Copyright 2009 SETAC.

Fate of trace organic compounds during vadose zone soil treatment in an onsite wastewater system

Science.gov (United States)

Conn, K.E.; Siegrist, R.L.; Barber, L.B.; Meyer, M.T.

2010-01-01

During onsite wastewater treatment, trace organic compounds are often present in the effluents applied to subsurface soils for advanced treatment during vadose zone percolation and groundwater recharge. The fate of the endocrine-disrupting surfactant metabolites 4-nonylphenol (NP), 4-nonylphenolmonoethoxylate (NP1EO), and 4-nonylphenolmonoethoxycarboxylate (NP1EC), metal-chelating agents ethylenediaminetetraacetic acid (EDTA) and nitrilotriacetic acid (NTA), antimicrobial agent triclosan, stimulant caffeine, and antibiotic sulfamethoxazole during transport through an unsaturated sandy loam soil was studied at a field-scale test site. To assess the effects of effluent quality and hydraulic loading rate (HLR) on compound fate in the soil profile, two effluents (septic tank or textile biofilter) were applied at two design HLRs (2 or 8 cm/d). Chemical concentrations were determined in the two effluents and soil pore water at 60, 120, and 240 cm below the soil infiltrative surface. Concentrations of trace organic compounds in septic tank effluent were reduced by more than 90% during transport through 240 cm (often within 60 cm) of soil, likely due to sorption and biotransformation. However, the concentration of NP increased with depth in the shallow soil profile. Additional treatment of anaerobic septic tank effluent with an aerobic textile biofilter reduced effluent concentrations of many compounds, but generally did not affect any changes in pore water concentrations. The soil profile receiving septic tank effluent (vs. textile biofilter effluent) generally had greater percent removal efficiencies. EDTA, NP, NP1EC, and sulfamethoxazole were measured in soil pore water, indicating the ability of some trace organic compounds to reach shallow groundwater. Risk is highly dependent on the degree of further treatment in the saturated zone and the types and proximity of uses for the receiving groundwater environment. ?? 2009 SETAC.

Core-logs of borehole VI down to 505 m

International Nuclear Information System (INIS)

Carlsson, L.; Olsson, T.; Stejskal, V.

1981-01-01

In the hydrogeological program of the Stripa project the vertical borehole V1 has been drilled 505.5 m. The drillcore has been logged with regard to rock characteristic, fracture frequency, dipping and filling. The results presented as cumulative fracture diagram have formed the base for subdivision of the borehole according to fracture frequency. The variation in the fracture dipping was also taken into account. Chlorite is the most common of the infilling material in the fractures. For the borehole 0-466 m the average fracture frequency is 1.46 fractures/m. Below 466 m the core is highly fractured and crushed indicating that the borehole has entered a crushed zone. Because of this the drilling is temporarily stopped. (Auth.)

Trace Metals in Groundwater and the Vadose Zone Calcite: In Situ Containment and Stabilization of Strontium-90 and Other Divalent Metals and Radionuclides at Arid West DOE

International Nuclear Information System (INIS)

Smith, Robert W.

2004-01-01

Radionuclide and metal contaminants such as strontium-90 are present beneath U.S. Department of Energy (DOE) lands in both the groundwater (e.g., 100-N area at Hanford, WA) and vadose zone (e.g., Idaho Nuclear Technology and Engineering Center at the Idaho National Engineering and Environmental Laboratory). In situ containment and stabilization of these contaminants is a cost-effective treatment strategy. However, implementing in situ containment and stabilization approaches requires definition of the mechanisms that control contaminant sequestration. We are investigating the in situ immobilization of radionuclides or contaminant metals (e.g., strontium-90) by their facilitated co-precipitation with calcium carbonate in groundwater and vadose zone systems. Our facilitated approach, shown schematically in Figure 1, relies upon the hydrolysis of introduced urea to cause the acceleration of calcium carbonate precipitation (and trace metal co-precipitation) by increasing pH and alkalinity. Subsurface urea hydrolysis is catalyzed by the urease enzyme, which may be either introduced with the urea or produced in situ by ubiquitous subsurface urea hydrolyzing microorganisms. Because the precipitation process tends to be irreversible and many western aquifers are saturated with respect to calcite, the co-precipitated metals and radionuclides will be effectively removed from the aqueous phase over the long-term. Another advantage of the ureolysis approach is that the ammonium ions produced by the reaction can exchange with radionuclides sorbed to subsurface minerals, thereby enhancing the availability of the radionuclides for re-capture in a more stable solid phase (co-precipitation rather than adsorption)

Optimization of Deep Borehole Systems for HLW Disposal

International Nuclear Information System (INIS)

Driscoll, Michael; Baglietto, Emilio; Buongiorno, Jacopo; Lester, Richard; Brady, Patrick; Arnold, B. W.

2015-01-01

This is the final report on a project to update and improve the conceptual design of deep boreholes for high level nuclear waste disposal. The effort was concentrated on application to intact US legacy LWR fuel assemblies, but conducted in a way in which straightforward extension to other waste forms, host rock types and countries was preserved. The reference fuel design version consists of a vertical borehole drilled into granitic bedrock, with the uppermost kilometer serving as a caprock zone containing a diverse and redundant series of plugs. There follows a one to two kilometer waste canister emplacement zone having a hole diameter of approximately 40-50 cm. Individual holes are spaced 200-300 m apart to form a repository field. The choice of verticality and the use of a graphite based mud as filler between the waste canisters and the borehole wall liner was strongly influenced by the expectation that retrievability would continue to be emphasized in US and worldwide repository regulatory criteria. An advanced version was scoped out using zinc alloy cast in place to fill void space inside a disposal canister and its encapsulated fuel assembly. This excludes water and greatly improves both crush resistance and thermal conductivity. However the simpler option of using a sand fill was found adequate and is recommended for near-term use. Thermal-hydraulic modeling of the low permeability and porosity host rock and its small (@@@ 1%) saline water content showed that vertical convection induced by the waste's decay heat should not transport nuclides from the emplacement zone up to the biosphere atop the caprock. First order economic analysis indicated that borehole repositories should be cost-competitive with shallower mined repositories. It is concluded that proceeding with plans to drill a demonstration borehole to confirm expectations, and to carry out priority experiments, such as retention and replenishment of in-hole water is in order.

Optimization of Deep Borehole Systems for HLW Disposal

Energy Technology Data Exchange (ETDEWEB)

Driscoll, Michael [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Baglietto, Emilio [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Buongiorno, Jacopo [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Lester, Richard [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Brady, Patrick [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Arnold, B. W. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2015-09-09

This is the final report on a project to update and improve the conceptual design of deep boreholes for high level nuclear waste disposal. The effort was concentrated on application to intact US legacy LWR fuel assemblies, but conducted in a way in which straightforward extension to other waste forms, host rock types and countries was preserved. The reference fuel design version consists of a vertical borehole drilled into granitic bedrock, with the uppermost kilometer serving as a caprock zone containing a diverse and redundant series of plugs. There follows a one to two kilometer waste canister emplacement zone having a hole diameter of approximately 40-50 cm. Individual holes are spaced 200-300 m apart to form a repository field. The choice of verticality and the use of a graphite based mud as filler between the waste canisters and the borehole wall liner was strongly influenced by the expectation that retrievability would continue to be emphasized in US and worldwide repository regulatory criteria. An advanced version was scoped out using zinc alloy cast in place to fill void space inside a disposal canister and its encapsulated fuel assembly. This excludes water and greatly improves both crush resistance and thermal conductivity. However the simpler option of using a sand fill was found adequate and is recommended for near-term use. Thermal-hydraulic modeling of the low permeability and porosity host rock and its small (≤ 1%) saline water content showed that vertical convection induced by the waste’s decay heat should not transport nuclides from the emplacement zone up to the biosphere atop the caprock. First order economic analysis indicated that borehole repositories should be cost-competitive with shallower mined repositories. It is concluded that proceeding with plans to drill a demonstration borehole to confirm expectations, and to carry out priority experiments, such as retention and replenishment of in-hole water is in order.

Spectroscopic and Microscopic Characterization of Contaminant Uptake and Retention by Carbonates in the Soil and Vadose Zone

International Nuclear Information System (INIS)

Reeder, Richard J.; Fisher, Nicholas S.; Hess, Wayne P.; Beck, Kenneth M.

2003-01-01

The research focus of this previous EMSP grant was assessment of the role that carbonate minerals play in the uptake and sequestration of metal and radionuclide contaminants in soils and the vadose zone for conditions relevant to the Hanford Site and other sites in the DOE Complex. The project was a collaboration among researchers at SUNY-Stony Brook and EMSL/PNNL. Carbonates, particularly calcite, are present in the Hanford subsurface as grain coatings, disseminated particles, and dense caliche layers. Calcite is also predicted to be forming beneath leaking tanks. A range of metal and radionuclide species that pose risks at Hanford and other DOE sites were considered, including U(VI), Cr(CV), Cs, Pb(II), and selected lanthanides (as models for trivalent actinides). Batch sorption and co-precipitation experiments of these metals with pre-equilibrated calcite and selected uptake experiments on natural caliche formed the basis to determine the mechanisms of metal/radionuclide binding and to assess the effect on the stability of the sorbed species and the potential for remobilization. Our results provide ne information that can benefit DOE clean-up methodology and potentially provide new approaches for uptake of selected heavy metals

An analytical solution to assess the SH seismoelectric response of the vadose zone

Science.gov (United States)

Monachesi, L. B.; Zyserman, F. I.; Jouniaux, L.

2018-03-01

We derive an analytical solution of the seismoelectric conversions generated in the vadose zone, when this region is crossed by a pure shear horizontal (SH) wave. Seismoelectric conversions are induced by electrokinetic effects linked to relative motions between fluid and porous media. The considered model assumes a one-dimensional soil constituted by a single layer on top of a half space in contact at the water table, and a shearing force located at the earth's surface as the wave source. The water table is an interface expected to induce a seismoelectric interfacial response (IR). The top layer represents a porous rock which porous space is partially saturated by water and air, while the half-space is completely saturated with water, representing the saturated zone. The analytical expressions for the coseismic fields and the interface responses, both electric and magnetic, are derived by solving Pride's equations with proper boundary conditions. An approximate analytical expression of the solution is also obtained, which is very simple and applicable in a fairly broad set of situations. Hypothetical scenarios are proposed to study and analyse the dependence of the electromagnetic fields on various parameters of the medium. An analysis of the approximate solution is also made together with a comparison to the exact solution. The main result of the present analysis is that the amplitude of the interface response generated at the water table is found to be proportional to the jump in the electric current density, which in turn depends on the saturation contrast, poro-mechanical and electrical properties of the medium and on the amplitude of the solid displacement produced by the source. This result is in agreement with the one numerically obtained by the authors, which has been published in a recent work. We also predict the existence of an interface response located at the surface, and that the electric interface response is several orders of magnitude bigger than

An analytical solution to assess the SH seismoelectric response of the vadose zone

Science.gov (United States)

Monachesi, L. B.; Zyserman, F. I.; Jouniaux, L.

2018-06-01

We derive an analytical solution of the seismoelectric conversions generated in the vadose zone, when this region is crossed by a pure shear horizontal (SH) wave. Seismoelectric conversions are induced by electrokinetic effects linked to relative motions between fluid and porous media. The considered model assumes a 1D soil constituted by a single layer on top of a half-space in contact at the water table, and a shearing force located at the earth's surface as the wave source. The water table is an interface expected to induce a seismoelectric interfacial response (IR). The top layer represents a porous rock in which porous space is partially saturated by water and air, while the half-space is completely saturated with water, representing the saturated zone. The analytical expressions for the coseismic fields and the interface responses, both electric and magnetic, are derived by solving Pride's equations with proper boundary conditions. An approximate analytical expression of the solution is also obtained, which is very simple and applicable in a fairly broad set of situations. Hypothetical scenarios are proposed to study and analyse the dependence of the electromagnetic fields on various parameters of the medium. An analysis of the approximate solution is also made together with a comparison to the exact solution. The main result of the present analysis is that the amplitude of the interface response generated at the water table is found to be proportional to the jump in the electric current density, which in turn depends on the saturation contrast, poro-mechanical and electrical properties of the medium and on the amplitude of the solid displacement produced by the source. This result is in agreement with the one numerically obtained by the authors, which has been published in a recent work. We also predict the existence of an interface response located at the surface, and that the electric interface response is several orders of magnitude bigger than the

Moisture monitoring in large diameter boreholes

International Nuclear Information System (INIS)

Tyler, S.

1985-01-01

The results of both laboratory and field experiments indicate that the neutron moisture gauge traditionally used in soil physics experiments can be extended for use in large diameter (up to 15 cm) steel-cased boreholes with excellent results. This application will permit existing saturated zone monitoring wells to be used for unsaturated zone monitoring of recharge, redistribution and leak detection from waste disposal facilities. Its applicability to large diameter cased wells also gives the soil physicist and ground-water hydrologist and new set of monitoring points in the unsaturated zone to study recharge and aquifer properties. 6 refs., 6 figs., 2 tabs

The boreholes and geology of the Down Ampney fault research site

International Nuclear Information System (INIS)

Brightman, M.A.; Hallam, J.R.; Ambrose, K.; Horton, A.

1991-01-01

An exploratory programme of core drilling confirmed the location of a major fault with a 50-m throw and 70 0 dip and provided geological reference sections. These data enabled a measurement array of boreholes to be planned and constructed for the geophysical and hydrogeological characterization of the fault. Full details are given of the design, drilling, coring, completion and surveying of the 22 boreholes. The geological sequence is described, together with the structure of the fault zone, which was penetrated by eight boreholes

a Borehole-Dilution Method for Quantifying Vertical Darcy Fluxes in the Hyporheic Zone

Science.gov (United States)

Augustine, S. D.; Annable, M. D.; Cho, J.

2017-12-01

The borehole dilution method has consistently and successfully been used for estimating local water fluxes, however, this method can be relatively labor intensive and expensive. The focus of this research is aimed at developing a low-cost, borehole dilution method for quantifying vertical water fluxes in the hyporheic zone at the surface-groundwater interface. This would allow for the deployment of multiple units within a targeted surface water body and thus produce high-resolution, spatially distributed data on the infiltration rates over a short period of time with minimal set-up requirements. The device consists of a 2-inch, inner diameter PVC pipe containing short, screened sections in its upper and lower segments. The working unit is driven into the sediment and acts as a continuous flow reactor creating a pathway between the subsurface pore-water and the overlying surface water where the presence of a hydraulic gradient facilitates vertical movement. We developed a simple electrode and tracer-injection system housed within the unit to inject and measure salt tracer concentrations at the desired intervals while monitoring and storing those measurements using open-source Arduino technology. Preliminary lab and field scale trials provided data that was fit to both zero and first order reaction rate functions for analysis. The field test was conducted over approximately one day within a wet retention basin. The initial results estimated a vertical Darcy flux of 113.5 cm/d. Additional testing over a range of expected Darcy fluxes will be presented along with an evaluation considering enhanced water flow due to the high hydraulic conductivity of the device.

Seismic Readings from the Deepest Borehole in the New Madrid Seismic Zone

Energy Technology Data Exchange (ETDEWEB)

Woolery, Edward W [KY Geological Survey, Univ of KY; Wang, Zhenming [KY Geological Survey, Univ of KY; Sturchio, Neil C [Dept of earth and Env. Sciences, Univ of Ill at Chicago

2006-03-01

Since the 1980s, the research associated with the UK network has been primarily strong-motion seismology of engineering interest. Currently the University of Kentucky operates a strong-motion network of nine stations in the New Madrid Seismic Zone. A unique feature of the network is the inclusions of vertical strong-motion arrays, each with one or two downhole accelerometers. The deepest borehole array is 260 m below the surfaces at station VASA in Fulton County, Kentucky. A preliminary surface seismic refraction survey was conducted at the site before drilling the hole at VSAS (Woolery and Wang, 2002). The depth to the Paleozoic bedrock at the site was estimated to be approximately 595 m, and the depth to the first very stiff layer (i.e. Porters Creek Clay) was found to be about 260 m. These depths and stratigraphic interpretation correlated well with a proprietary seismic reflection line and the Ken-Ten Oil Exploration No. 1 Sanger hole (Schwalb, 1969), as well as our experience in the area (Street et al., 1995; Woolery et al., 1999).

A strategy to seal exploratory boreholes in unsaturated tuff

International Nuclear Information System (INIS)

Fernandez, J.A.; Case, J.B.; Givens, C.A.; Carney, B.C.

1994-04-01

This report presents a strategy for sealing exploratory boreholes associated with the Yucca Mountain Site Characterization Project. Over 500 existing and proposed boreholes have been considered in the development of this strategy, ranging from shallow (penetrating into alluvium only) to deep (penetrating into the groundwater table). Among the comprehensive list of recommendations are the following: Those boreholes within the potential repository boundary and penetrating through the potential repository horizon are the most significant boreholes from a performance standpoint and should be sealed. Shallow boreholes are comparatively insignificant and require only nominal sealing. The primary areas in which to place seals are away from high-temperature zones at a distance from the potential repository horizon in the Paintbrush nonwelded tuff and the upper portion of the Topopah Spring Member and in the tuffaceous beds of the Calico Hills Unit. Seals should be placed prior to waste emplacement. Performance goals for borehole seals both above and below the potential repository are proposed. Detailed construction information on the boreholes that could be used for future design specifications is provided along with a description of the environmental setting, i.e., the geology, hydrology, and the in situ and thermal stress states. A borehole classification scheme based on the condition of the borehole wall in different tuffaceous units is also proposed. In addition, calculations are presented to assess the significance of the boreholes acting as preferential pathways for the release of radionuclides. Design calculations are presented to answer the concerns of when, where, and how to seal. As part of the strategy development, available technologies to seal exploratory boreholes (including casing removal, borehole wall reconditioning, and seal emplacement) are reviewed

Site characterization and validation - Borehole radar investigations stage 3

International Nuclear Information System (INIS)

Sandberg, E.; Olsson, O.; Falk, L.

1989-11-01

The borehole radar investigation program Stage 3 of the SCV-site has comprised single hole reflection measurements with centre frequencies of 22 and 60 MHz. Single hole reflection measurement with both omni-directional and directional antennas have been performed in the boreholes C1, C2, C3 and the D-holes. Crosshole tomographic measurements as well as cross- hole reflection measurement have been made between the bore- holes C1-C2, W1-C1 and W1-C2. The range obtained in the single hole reflection measurements was approximately 100 m for the lower frequency and about 60-70 m for the centre frequency 60 MHz. In the crosshole measurements transmitter-receiver separations from 20 to 120 m have been used. The Stage 3 radar investigations have essentially confirmed the three dimensional description of the structures at the SCV-site. The conceptual model of the site which was produced based on the Stage 1 data included three major zones, two minor zones and a circular feature. The major features are considered to be the most significant at the site and are all observed in the Stage 3 boreholes close to their predicted locations. The circular feature has also been found in two of the additional tomograms at the predicted location. The results indicate that the zones are not homogeneous but rather that they are highly irregular containing parts of considerably increased fracturing and parts where their contrast to the background rock is quite small. The zones appear to be approximately planar at least at the scale of the site. At a smaller scale the zones can appear quite irregular

VTT test borehole for bedrock investigations

International Nuclear Information System (INIS)

Okko, O.; Hassinen, P.; Front, K.

1994-02-01

A borehole of depth 150 m and diameter 56 mm has been drilled in the area adjacent to the premises of the Technical Research Centre of Finland (VTT) at Otaniemi, Espoo, for the purposes of calibrating geophysical measurements devices. This report presents the test results obtained so far and illustrates the processing of these, in which the various measurements are plotted as curves and combinations of curves. The interpretations provided so far consists of analyses of lithological variations, bedrock fracturing, the nature and occurrence of fracture zones and groundwater flow patterns. Samples were taken from those parts of the core shown by the borehole measurements to be homogenous and thin sections made from these for mineralogical determinations. The rock mechanical and petrophysical properties of the same points were examined. The core is in the possession of VTT, and the hole itself is available to outsiders for the calibration and testing of borehole measurement equipment. (orig.). (21 refs., 13 figs., 5 tabs.)

Mechanical properties of fracture zones

International Nuclear Information System (INIS)

Leijon, B.

1993-05-01

Available data on mechanical characteristics of fracture zones are compiled and discussed. The aim is to improve the basis for adequate representation of fracture zones in geomechanical models. The sources of data researched are primarily borehole investigations and case studies in rock engineering, involving observations of fracture zones subjected to artificial load change. Boreholes only yield local information about the components of fracture zones, i.e. intact rock, fractures and various low-strength materials. Difficulties are therefore encountered in evaluating morphological and mechanical properties of fracture zones from borehole data. Although often thought of as macroscopically planar features, available field data consistently show that fracture zones are characterized by geometrical irregularities such as thickness variations, surface undulation and jogs. These irregularities prevail on all scales. As a result, fracture zones are on all scales characterized by large, in-plane variation of strength- and deformational properties. This has important mechanical consequences in terms of non-uniform stress transfer and complex mechanisms of shear deformation. Field evidence for these findings, in particular results from the underground research laboratory in Canada and from studies of induced fault slip in deep mines, is summarized and discussed. 79 refs

Geophysical borehole logging in Lavia borehole - results and interpretation of sonic and tube wave measurements

International Nuclear Information System (INIS)

Andersson, P.; Stenberg, L.

1985-02-01

Swedish Nuclear Fuel and Waste Management Co, SKB has been contracted by Industrial Power Company LTD, TVO to perform geophysical logging in a borehole at Lavia in Western Finland. The logging has been conducted by Swedish Geological Co, SGAB in accordance with an agreement for cooperation with SKB. The depth of the borehole is 1001 m, diameter 56 mm and inclination 10-20 degrees to the vertical. The aim of the logging was to determine the various geophysical parameters in the borehole in order to interpret and understand the rock mass properties in the vicinity of the borehole. According to the contract the report covers the following main objectives: a technical description of the field work and the equipment used; a review of the theoretical base for the sonic and tube wave methods; an interpretation and presentation of the results obtained by sonic and tube wave mesurements. The evaluation of the sonic and tube wave measurements shows good correlation. On a qualitative basis there seems to be a correlation between tube wave generating points, the relative tube wave amplitudes and the hydraulic conductivity measurements performed as hydraulical tests between packers in the borehole. The low velocity anamalies in the sonic log are mainly caused by tectonic features like fractures and fracture zones but to some extent also by contacts between granite and diorite. The estimation of elastic properties of the rock mass from observation of tube wave velocity are in accordance with laboratory determinations made on core samples. (author)

Core drilling of deep borehole OL-KR32 at Olkiluoto in Eurajoki 2004

International Nuclear Information System (INIS)

Rautio, T.

2005-01-01

Posiva Oy submitted an application for the Decision in Principle to the Finnish Government in May 1999. A positive decision was made at the end of 2000 by the Government. The Finnish Parliament ratified the Decision in Principle on the final disposal facility for spent nuclear fuel at Olkiluoto, Eurajoki in May 2001. The decision makes it possible for Posiva to focus the confirming bedrock investigations at Olkiluoto, where in the next few years an underground rock characterisation facility, the ONKALO, will be constructed. As a part of the investigations Suomen Malmi Oy (Smoy) core drilled a 191.81 m deep borehole with a diameter of 75.7 mm at Olkiluoto in November 2004. This borehole was aimed to get additional information of the quality and the location of the fractured zones R20A and R20B and the fractured zones near rock surface noticed in investigation trench TK8. The identification number of the borehole is OL-KR32. A set of monitoring measurements and samplings from the drilling and returning water was carried out during the drilling. Both the volume and the electric conductivity of the drilling water and the returning water were recorded as well as the pressure of the drilling water. The objective of these measurements was to obtain more information about bedrock and groundwater properties. Sodium fluorescein was used as a label agent in the drilling water. The volume of the used drilling water was about 93 m 3 and the measured volume of the returning water was about 6 m 3 in borehole OL-KR32. The deviation of the borehole was measured with the deviation measuring instruments EMS and Maxibor. The results of the Maxibor measurements indicate that borehole OL-KR32 deviates 4.42 m right and 4.66 m up at the borehole depth of 189 m. Uniaxial compressive strength, Young's Modulus and Poisson's ratio were measured from the core samples. The average uniaxial compressive strength is about 130 MPa, the average Young's modulus is 47 GPa and the average Poisson

Recordings from the deepest borehole in the New Madrid Seismic Zone

Science.gov (United States)

Wang, Z.; Woolery, E.W.

2006-01-01

The recordings at the deepest vertical strong-motion array (VSAS) from three small events, the 21 October 2004 Tiptonville, Tennessee, earthquake; the 10 February 2005 Arkansas earthquake; and the 2 June 2005 Ridgely, Tennessee, earthquake show some interesting wave-propagation phenomena through the soils: the S-wave is attenuated from 260 m to 30 m depth and amplified from 30 m to the surface. The S-wave arrival times from the three events yielded different shear-wave velocity estimates for the soils. These different estimates may be the result of different incident angles of the S-waves due to different epicentral distances. The epicentral distances are about 22 km, 110 km, and 47 km for the Tiptonville, Arkansas, and Ridgely earthquakes, respectively. These recordings show the usefulness of the borehole strong-motion array. The vertical strong-motion arrays operated by the University of Kentucky have started to accumulate recordings that will provide a database for scientists and engineers to study the effects of the near-surface soils on the strong ground motion in the New Madrid Seismic Zone. More information about the Kentucky Seismic and Strong-Motion Network can be found at www.uky.edu/KGS/geologichazards. The digital recordings are available at ftp://kgsweb.uky.edu.

Difference flow measurements in borehole KOV01 at Oskarshamn

International Nuclear Information System (INIS)

Poellaenen, J.; Rouhiainen, P.

2001-09-01

Posiva Flow Log/Difference Flow method can be used for relatively fast determination of hydraulic conductivity and hydraulic head in fractures or fractured zones in cored boreholes. This report presents the principles of the method as well as the results of the measurements carried out in borehole KOV01 at Oskarshamn in February and March 2001. The aim of the measurements presented in this report was to determine the depth and flow rate of flowing fractures in borehole KOV01 prior to groundwater sampling. The measurements in borehole KOV01 were carried out between 100-1000 m depth using the so called detailed flow logging mode; the flow rate into a 5 m long test section was measured. Detailed flow logging was repeated at the location of the detected flow anomalies using 0.5 m section length and 0.1 m point intervals. The borehole was pumped during these measurements. The occurrence of saline water in the borehole was studied by electric conductivity measurements. The flow guide encloses also an electrode for measuring of single point resistance of the bedrock. It was measured with 0.01 m point intervals during the detailed flow logging. Depth calibration was made on the basis of the known depth marks in the borehole. The depth marks were detected by caliper measurements and by single point resistance measurements

Geological data summary for a borehole drilled between 1991 September 16 and 1991 October 1 for the Transport Properties in Highly Fractured Rock Experiment at the Underground Research Laboratory

Energy Technology Data Exchange (ETDEWEB)

Woodcock, D. R.; Everitt, R. A.

1992-08-01

Borehole 101-013-HG4 was drilled between 1991 September 16 and October 1 from the 130 Level station, as part of the Transport Properties in Highly Fractured Rock Experiment, to explore the geological, hydrogeological and geochemical conditions of the rock mass in an area northwest of the Underground Research Laboratory (URL) shaft. The borehole was drilled to provide information at an intersection with Fracture Zone 2.0, 100 m to the west of boreholes collared from Room 211 of the 240 Level for future solute transport experiments within Fracture Zone 2.0, and to further our understanding of the rock mass in the area. Fracture Zones 2.5, 2.0, 1.9 and a subvertical joint zone in the footwall were all intersected in the borehole. Preliminary results from detailed core logging show that the lithostructural domains intersected in the borehole correlate with those previously identified in the URL shaft, and in nearby exploration boreholes drilled from the 130 Level. The domains are shallow-dipping toward the southeast and are parallel to the three main fracture zones intersected in the borehole.

Borehole radar measurements performed on preliminary investigation areas in Finland for final disposal of spent nuclear fuel

International Nuclear Information System (INIS)

Carlsten, S.

1991-05-01

Borehole radar measurements with the RAMAC system have been performed in 24 boreholes distributed between the investigation areas Kuhmo Romuvaara, Hyrynsalmi Veitsivaara, Konginkangas Kivetty, Sievi Syyry, and Eurajoki Olkiluoto. The purpose of the borehole radar measurement program has been to investigate the bedrock in the vicinity of the boreholes in order to obtain information about geometry and extent of fracture zones, lithological contacts and other structures. The measurements have been performed as singlehole radar reflection measurements and Vertical Radar Profiling (VRP) measurements, using antennas with 22 MHz frequency range in both configurations. The total measured length in the singlehole radar reflection mode is 13304 meter and in the VRP mode 9200 meter. The VRP measurements are not presented in the report. Radar data from the singlehole reflection measurements are presented as grey scale radar maps after digital filtering with a bandpass filter and a moving average filter. Interpreted zones from the singlehole radar measurements are presented in tables for each borehole. It has been possible to study structures at distances of more than 110 meter from the borehole

Geophysical and geological borehole investigations for the characterization of a site for radioactive waste disposal

International Nuclear Information System (INIS)

Olsson, O.; Ahlbom, K.

1984-02-01

In the Swedish program for site investigations detailed geological and geophysical investigations are performed at areas of 4-6 km 2 at the surface. Normally around 10 deep core bore holes are drilled. The length of the holes is normally from 600 to 1000 m. The holes are drilled to verify the location of fracture zones and to investigate the physical and hydraulic properties of the fracture zones at large depths. Investigations have been performed in a number of sites with mainly granitic and gneissic rocks. The core from these boreholes is logged with the aid of a microcomputer system. The cores are mapped with respect to rock type, structure, fractures and fracture minerals. Indications of water flow, shearing and core-discing are also studied. The boreholes are logged with a suite of geophysical logs. Several different electrical logs are used and have been found to be good indicators of fracture zones. Normally the electrical logs in combination with the fracture frequency are used to define the limits of fracture zones crossing the borehole. The temperature log and the salinity log have proved to be good indicators of permeable zones. The data from each hole is correlated with data obtained from the other holes and the surface investigations to build a fracture zone model which is used for the hydraulic modelling of the site. In order to verify the extension of the fracture zones at a distance from the borehole cross-hole techniques have been applied. At the Swedish test site Finnsjoe and in the Stripa mine the suitability of the mise a la masse technique for mapping of fracture zones was tested. At the Finnsjoe site it was possible to map a fairly complex fracture system over distances up to 150 m. In the Stripa mine the object was to follow the extent of a major fracture zone for distances up to 600 m. It was possible to obtain an indication of the orientation of the fracture zone

Flow measurements in boreholes PHO1 and PHO2 in ONKALO

International Nuclear Information System (INIS)

Rouhiainen, P.; Pollanen, J.

2005-10-01

Posiva Flow Log/Difference Flow method can be used for relatively fast determination of hydraulic properties of fractures or fractured zones in boreholes. The flow sensor for flow along a borehole and a special flow guide are used for this measurement. This report presents the principles of the method as well as the results of the measurements carried out in the underground facilities of the ONKALO. Pilot boreholes PH01 and PH02 were measured. Borehole PH01 was measured on February 2004 and borehole PH02 on December 2004. Borehole PH01 was measured using 2 m section when it was in natural sate (without pumping it) and when water was pumped out from it. The upper part of the borehole was also measured when water was injected into the borehole. In addition to this, a detailed flow log was performed with 0.1 m point intervals using 0.5 m section length when water was pumped out from the borehole. Borehole PH02 was measured only with 0.5 m section length. The borehole was open during measurements and there was a natural outflow from the borehole during measurements. The flow guide encloses an electrode for single point resistance measurement, which was also carried out with 0.01 m point intervals during the flow measurements. Flow measurement and single point resistance measurement were used to locate flowing fractures and to evaluate their transmissivity. Electric conductivity (EC) and temperature of water was registered during flow logging. The conductivity values are temperature corrected to 25 deg C. (orig.)

Focused modelling. Fracture identification in Olkiluoto borehole OL-KR04

International Nuclear Information System (INIS)

Jokinen, J.; Jakobsson, K.

2004-10-01

An extensive set of measured borehole data has been obtained from geological repository investigations in the bedrock of Olkiluoto. Our hypothesis is that geophysical data may be used more efficiently to identify and classify fracture zones. It is known that several geophysical logging methods yield useful information outside the borehole walls that cannot be reached otherwise. At present, this data is used for additional fracture characterization but not for identification purposes. The study focuses on the application of 14 different geophysical data measured in the borehole OL-KR04. The whole data set is divided into main groups using the Principal Component Analysis (PCA). Each group is composed mainly of sensitive methods detecting specific physical characteristics. The main groups from the geophysical point of view are open fractures, reduced density, increased electrical conductivity, and increased natural radiation. The Varimax optimization method is used to maximize the importance of supporting data as well as to emphasize differences between the discovered principal components. In fracture zone analysis, drilling core samples and the hydrological measurement results form an indispensable data set. For practical reasons, and in order to fulfill the requirements of the PCA analysis, S-wave velocity and electrical resistivity measurements are also performed. A combination of these methods, simultaneously applied using suitable 'trigger limits', identifies penetrated extensive fracture sections in a borehole cost-effectively and unambiguously. (orig.)

Polarimetric borehole radar measurement near Nojima fault and its application to subsurface crack characterization; Polarimetric borehole radar ni yoru Nojima danso shuhen no chika kiretsu keisoku jikken

Energy Technology Data Exchange (ETDEWEB)

Sato, M.; Taniguchi, Y.; Miwa, T.; Niitsuma, H. [Tohoku University, Sendai (Japan); Ikeda, R. [National Research Institute for Disaster Prevention, Tsukuba (Japan); Makino, K. [Geophysical Surveying and Consulting Co. Ltd., Tokyo (Japan)

1997-05-27

Practical application of subsurface crack characterization by the borehole radar measurement to which the radar polarimetric method was introduced was attempted to measuring objects for which the borehole radar has not been much used, for example, the inside of low loss rock mass or fracture zone where cracks tightly exist. A system was trially manufactured which makes the radar polarimetric measurement possible in the borehole at a 1000m depth and with a about 10cm diameter, and a field experiment was conducted for realizing the subsurface crack characterization near the Nojima fault. For the measuring experiment by the polarimetric borehole radar, used were Iwaya borehole and Hirabayashi borehole drilled in the north of Awaji-shima, Hyogo-ken. In a comparison of both polarization systems of Hirabayashi borehole, reflected waves at depths of 1038m and 1047m are relatively stronger in both polarization systems than those with the same polarization form and at different depths, whereas reflected waves around a 1017m depth are strong only as to the parallel polarization system. Characteristics of the polarization in this experiment indirectly reflect crack structures. 6 refs., 6 figs., 1 tab.

Calculation of the apparent neutron parameters in a borehole geometry for neutron porosity tools

International Nuclear Information System (INIS)

Woznicka, U.; Drabina, A.

2001-01-01

This paper presents the next step of a development of the theoretical solutions, which gives a possibility to calculate the apparent neutron slowing down and migration lengths in the three region cylindrical system which represents the borehole, the intermediate zone (e.g. mud cake at the borehole walls), and the geological formation. A solution of the neutron diffusion equation in energy two-group approach for spatial moments of the neutron flux is given for the three-region cylindrical coaxial geometry. The influence of the intermediate zone is presented. The numerical code MOM3 has been written to calculate the apparent slowing down and migration lengths for the three-region cylindrical system as mentioned above. Additionally the MCNP calculation for the three-region borehole geometry is presented in the paper

Core drilling of deep borehole OL-KR32 at Olkiluoto in Eurajoki 2004

Energy Technology Data Exchange (ETDEWEB)

Rautio, T. [Suomen Malmi Oy, Espoo (Finland)

2005-01-15

Posiva Oy submitted an application for the Decision in Principle to the Finnish Government in May 1999. A positive decision was made at the end of 2000 by the Government. The Finnish Parliament ratified the Decision in Principle on the final disposal facility for spent nuclear fuel at Olkiluoto, Eurajoki in May 2001. The decision makes it possible for Posiva to focus the confirming bedrock investigations at Olkiluoto, where in the next few years an underground rock characterisation facility, the ONKALO, will be constructed. As a part of the investigations Suomen Malmi Oy (Smoy) core drilled a 191.81 m deep borehole with a diameter of 75.7 mm at Olkiluoto in November 2004. This borehole was aimed to get additional information of the quality and the location of the fractured zones R20A and R20B and the fractured zones near rock surface noticed in investigation trench TK8. The identification number of the borehole is OL-KR32. A set of monitoring measurements and samplings from the drilling and returning water was carried out during the drilling. Both the volume and the electric conductivity of the drilling water and the returning water were recorded as well as the pressure of the drilling water. The objective of these measurements was to obtain more information about bedrock and groundwater properties. Sodium fluorescein was used as a label agent in the drilling water. The volume of the used drilling water was about 93 m{sup 3} and the measured volume of the returning water was about 6 m{sup 3} in borehole OL-KR32. The deviation of the borehole was measured with the deviation measuring instruments EMS and Maxibor. The results of the Maxibor measurements indicate that borehole OL-KR32 deviates 4.42 m right and 4.66 m up at the borehole depth of 189 m. Uniaxial compressive strength, Young's Modulus and Poisson's ratio were measured from the core samples. The average uniaxial compressive strength is about 130 MPa, the average Young's modulus is 47 GPa and

Hydrogeological characterisation using cross-borehole ground penetration radar and electrical resistivity tomography

DEFF Research Database (Denmark)

Zibar, Majken Caroline Looms

2007-01-01

was characterized by ~30 m thick unsaturated zone consisting mainly of sands of varying coarseness. Following an instrumentation of 16 boreholes two geophysical methods (cross-borehole ground penetrating radar and electrical resistivity tomography) were applied during natural precipitation and forced infiltration...... properties of the subsurface. On the other hand, volumetric moisture content variations of up to 5% were observed during a 20-day long forced infiltration experiment. The cross-borehole electrical resistance tomography and ground penetrating radar data collected during this experiment were subsequently....... The methods provided estimates of soil moisture content and electrical resistivity variations among 12 m deep boreholes located 5 – 7 m apart. The moisture content change following natural precipitation was observed to be practically negligible, providing minimal information to constrain the dynamic...

A Preliminary Assessment of a Deep Borehole disposal of Spent Fuels

International Nuclear Information System (INIS)

Lee, Younmyoung; Jeon, Jongtae

2014-01-01

Deep borehole disposal (DBD) of such radioactive waste as spent nuclear fuels (SFs) and other waste forms has been investigating mainly at Sandia National Labs for the US DOE as an alternative option. DBD can give advantages over less deep geological disposal since the disposal of wastes at a great depth where a low degree of permeability in the potentially steady rock condition will be beneficial for nuclide movement. Groundwater in the deep basement rock can even have salinity and less chance to mix with groundwater above. The DBD concept is quite straightforward and even simple: Waste canisters are simply emplaced in the lower 2 km part of the borehole down to 5 km deep. Through this study, a conceptual DBD is assessed for a similar case as the US DOE's approach, in which 400 SF canisters are to be emplaced at a deep bottom between 3km and 5km depths, upon which an additional 1km-thick compacted bentonite is overbuffered, and the remaining upper part of the borehole is backfilled again with a mixture of crushed rock and bentonite. Then, the total 5km-deep borehole has three zones: a disposal zone at the bottom 2km, a buffer zone at the next 1km, and backfill zone at the rest top 2km, as illustrated conceptually in Fig. 1. To demonstrate the feasibility in view of long-term radiological safety, a rough model for a safety assessment of this conceptual deep borehole repository system, providing detailed models for nuclide transport in and around the geosphere and biosphere under normal nuclide release scenarios that can occur after a closure of the repository, has been developed using GoldSim. A simple preliminary result in terms of the dose exposure rate from a safety assessment of the DBD is also presented and compared to the case of direct disposal of SFs in a KBS-3V vertical type repository, carried out in previous studies. For different types and shapes of repositories at each different depth, direct comparison between a DBD and a KBS-3 type disposal of

A Preliminary Assessment of a Deep Borehole disposal of Spent Fuels

Energy Technology Data Exchange (ETDEWEB)

Lee, Younmyoung; Jeon, Jongtae [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2014-05-15

Deep borehole disposal (DBD) of such radioactive waste as spent nuclear fuels (SFs) and other waste forms has been investigating mainly at Sandia National Labs for the US DOE as an alternative option. DBD can give advantages over less deep geological disposal since the disposal of wastes at a great depth where a low degree of permeability in the potentially steady rock condition will be beneficial for nuclide movement. Groundwater in the deep basement rock can even have salinity and less chance to mix with groundwater above. The DBD concept is quite straightforward and even simple: Waste canisters are simply emplaced in the lower 2 km part of the borehole down to 5 km deep. Through this study, a conceptual DBD is assessed for a similar case as the US DOE's approach, in which 400 SF canisters are to be emplaced at a deep bottom between 3km and 5km depths, upon which an additional 1km-thick compacted bentonite is overbuffered, and the remaining upper part of the borehole is backfilled again with a mixture of crushed rock and bentonite. Then, the total 5km-deep borehole has three zones: a disposal zone at the bottom 2km, a buffer zone at the next 1km, and backfill zone at the rest top 2km, as illustrated conceptually in Fig. 1. To demonstrate the feasibility in view of long-term radiological safety, a rough model for a safety assessment of this conceptual deep borehole repository system, providing detailed models for nuclide transport in and around the geosphere and biosphere under normal nuclide release scenarios that can occur after a closure of the repository, has been developed using GoldSim. A simple preliminary result in terms of the dose exposure rate from a safety assessment of the DBD is also presented and compared to the case of direct disposal of SFs in a KBS-3V vertical type repository, carried out in previous studies. For different types and shapes of repositories at each different depth, direct comparison between a DBD and a KBS-3 type disposal of

Effect of Stresses and Strains of Roadway Surrounding Rocks on Borehole Airtightness

Directory of Open Access Journals (Sweden)

WU Wei

2016-02-01

Full Text Available At present, many high gas and outburst mines have poor gas drainage effects. An important reason influencing the gas drainage effect is a poor hole-sealing effect. Most studies on gas drainage borehole sealing focus on local and foreign borehole sealing methods, borehole sealing equipment, and borehole sealing materials. Numerical simulations of initial drilling sealing depth are insufficient because studies on this subject are few. However, when the initial sealing depth of the borehole is not chosen reasonably, air can enter the gas drainage drill hole through the circumferential crack of roadway surrounding rocks under the influence of suction pressure of the drainage system. This phenomenon ultimately affects the hole-sealing effect. To improve the drilling hole sealing of gas drainage boring, we deduced the expression formulas of the crushing zone, plastic zone, and elastic zone around the coal-seam floor stone drift and conducted a stress–strain analysis of the coal-seam floor stone drift of the 2145 working surfaces of the Sixth Coal Mine of Hebi Coal Mine Group Company by using theoretical analysis, numerical simulation, and on-scene verification. Finally, we obtain the initial drilling sealing depth, which is a main contribution of this study. The results prove the following. The performed hole-sealing process with an initial drilling sealing depth of 8 m has a gas drainage efficiency of 55%. Compared with the previous 6.8 m initial drilling sealing depth with a gas drainage efficiency of less than 30%, which was adopted by the mine, the initial sealing depth of 8 m chosen in the numerical simulation is reasonable and conforms to the actual situation on the spot. Therefore, the initial drilling sealing depth chosen in the numerical simulation will produce practical and effective guidance to study the field hole-sealing depth.

Core drilling of deep borehole OL-KR33 at Olkiluoto in Eurajoki 2004

Energy Technology Data Exchange (ETDEWEB)

Rautio, T. [Suomen Malmi Oy, Espoo (Finland)

2005-01-15

Posiva Oy submitted an application for the Decision in Principle to the Finnish Government in May 1999. A positive decision was made at the end of 2000 by the Government. The Finnish Parliament ratified the Decision in Principle on the final disposal facility for spent nuclear fuel at Olkiluoto, Eurajoki in May 2001. The decision makes it possible for Posiva to focus the confirming bedrock investigations at Olkiluoto, where in the next few years an underground rock characterisation facility, the ONKALO, will be constructed. As a part of the investigations Suomen Malmi Oy (Smoy) core drilled 311.02 m and 45.53 m deep boreholes with a diameter of 75.7 mm at Olkiluoto in November-December 2004. These boreholes were aimed to get additional information of the quality of bedrock and the quality and the location of the fractured zones R2, RH9 and R72. The identification numbers of the boreholes are OL-KR33 and OL-KR33B, respectively. A set of monitoring measurements and samplings from the drilling and returning water was carried out during the drilling. Both the volume and the electric conductivity of the drilling water and the returning water were recorded as well as the pressure of the drilling water. The objective of these measurements was to obtain more information about bedrock and groundwater properties. Sodium fluorescein was used as a label agent in the drilling water. The volumes of the used drilling water were about 195m{sup 3} and 14m{sup 3} and the measured volumes of the returning water were about 100 m{sup 3} and 9 m{sup 3} in boreholes OL-KR33 and OL-KR33B, respectively. The deviations of the boreholes were measured with the deviation measuring instruments EMS and Maxibor. The results of the Maxibor measurements indicate that borehole OL-KR33 deviates 15.97 m right and 31.04 m up at the borehole depth of 309 m. Uniaxial compressive strength, Young's Modulus and Poisson's ratio were measured from the core samples. The average uniaxial compressive

Characterization of deep-seated rock masses by means of borehole investigation

International Nuclear Information System (INIS)

1982-04-01

Swedish State Power Board. The main objective of the programme was to test a method of measuring in-situ rock stresses in the deep, water-filled boreholes and to correlate measured rock stresses with the hydraulic and geological properties of the rock mass. The investigations consist of the following activities: - Coredrillin of two main boreholes with a depth of 500 m and 250 m respectively. - Rock stress measurements at 11 and 9 main levels in the boreholes respectively. At each level at least 3 complete measurements were made. - Logging of the cores with respect to rock type, fractures and fracture characteristics. - Water injection tests in the boreholes. The rock mass investigated is composed of a gneiss granite of Svecocarelian age (1500 Ma), with inclusions of younger pegmatites and greenstones of variable ages. The fracture density is as a mean 2 fractures per meter with a marked decrease in frequency with increased depth. The fractures are generally coated with calcite and chlorite as the dominating coating minerals. For the rock stress measurements, the method of Leeman and Hayes was chosen. The result show that there is a very high stress level in the rock mass, recordings of about 70 MPa were taken below a horizontal fracture zone at 320 m depth. In this lower rock masses the high stresses were also illustrated by intense disking of the hollow core which made measurements impossible in large sections of the boreholes. Water injection tests were performed, mainly as double-packer tests alon the entire boreholes. For the evaluation, both stationary and transient calculation theories were used and the results show a good agreement. The hyddraulic conductivities of the rock mass vary from below 10 -10 m/s up to 10 -7 m/s. The conductivity decreases with depth, though there are zones even at great depth with high conductivity. (Author)

Preliminary report on geophysical and mechanical borehole measurements at Stripa

International Nuclear Information System (INIS)

Nelson, P.; Paulsson, B.; Rachiele, R.; Andersson, L.; Schrauf, T.; Hustrulid, W.; Duran, O.; Magnusson, K.A.

1979-05-01

A suite of seven logs--neutron, gamma--gamma, resistivity, gamma ray, sonic, caliper, and temperature--operated in a borehole of 380-m depth located eleven zones where the rock permeability is expected to be enhanced due to the presence of open fractures. The sonic waveform record proved especially useful in this regard. Borehole measurements were also acquired in a large number of boreholes from 5- to 14-m length located in experimental drifts some 340-m underground. Here several physical properties, including the porosity, density, sonic velocity, and borehole rugosity, are generally quite uniform, with the exception of a few local chloritic zones and a few minor fractures. However, in situ determinations of the mechanical modulus with the CSM cell indicate substantial variability, with some apparent fracture control. Uranium and thorium concentrations are quite high in the Stripa granite, with local fluctuations associated with mineralogical changes as revealed by the gamma-ray log. A differential resistance probe appears promising as a sensitive detector of fine fracturing. A cross-hole ultrasonic system indicates variations of a few percent in compressional- and shear-wave velocities, reflecting the presence of fractures and changes in fracture characteristics as the rock is heated in a simulated storage test. The geophysical and mechanical data are being compared with the results from core and television logging, with hydrological test data on static pressure and injection permeability, and with displacements induced by thermal loading

Directional borehole antenna - Theory

International Nuclear Information System (INIS)

Falk, L.

1992-02-01

A directional antenna has been developed for the borehole radar constructed during phase 2 of the Stripa project. The new antenna can determine the azimuth of a strong reflector with an accuracy of about 3 degrees as confirmed during experiments in Stripa, although the ratio of borehole diameter to wavelength is small, about 0.03. The antenna synthesizes the effect of a loop antenna rotating in the borehole from four signals measured in turn by a stationary antenna. These signals are also used to calculate an electric dipole signal and a check sum which is used to examine the function of the system. The theory of directional antennas is reviewed and used to design an antenna consisting of four parallel wires. The radiation pattern of this antenna is calculated using transmission line theory with due regard to polarization, which is of fundamental importance for the analysis of directional data. In particular the multipole expansion of the field is calculated to describe the antenna radiation pattern. Various sources of error, e.g. the effect of the borehole, are discussed and the methods of calibrating the antenna are reviewed. The ambiguity inherent in a loop antenna can be removed by taking the phase of the signal into account. Typical reflectors in rock, e.g. fracture zones an tunnels, may be modelled as simple geometrical structures. The corresponding analysis is described and exemplified on measurements from Stripa. Radar data is nowadays usually analyzed directly on the computer screen using the program RADINTER developed within the Stripa project. An algorithm for automatic estimation of the parameters of a reflector have been tested with some success. The relation between measured radar data and external coordinates as determined by rotational indicators is finally expressed in terms of Euler angles. (au)

Study on the Geological Structure around KURT Using a Deep Borehole Investigation

International Nuclear Information System (INIS)

Park, Kyung Woo; Kim, Kyung Su; Koh, Yong Kwon; Choi, Jong Won

2010-01-01

To characterize geological features in study area for high-level radioactive waste disposal research, KAERI (Korea Atomic Energy Research Institute) has been performing the several geological investigations such as geophysical surveys and borehole drilling since 1997. Especially, the KURT (KAERI Underground Research Tunnel) constructed to understand the deep geological environments in 2006. Recently, the deep borehole of 500 m depths was drilled to confirm and validate the geological model at the left research module of the KURT. The objective of this research was to identify the geological structures around KURT using the data obtained from the deep borehole investigation. To achieve the purpose, several geological investigations such as geophysical and borehole fracture surveys were carried out simultaneously. As a result, 7 fracture zones were identified in deep borehole located in the KURT. As one of important parts of site characterization on KURT area, the results will be used to revise the geological model of the study area

Borehole sealing. Final report, March 1, 1973--October 31, 1973

Energy Technology Data Exchange (ETDEWEB)

Eilers, L.H.

1977-01-01

A program to evaluate existing materials and techniques to permanently plug boreholes penetrating salt strata near prospective radioactive waste depository sites is described. A new subcontract No. 78X-33542C has been issued to seal a borehole near Lyons, Kansas, using the materials and techniques recommended in this report. It is recommended that the well be thoroughly cleaned including removing any casing penetrating the critical salt strata. Following this, any fluid-bearing zones should be grouted using the best grout available. Silica gel was recommended for porous zones backed up by Portland cement to seal fractures and vugs. Recommendations were made to use sulfate resistant Chem Comp or sulfate resistant regular Portland (Type V) as the primary sealing material in the areas where anhydrite strata are present such as the existing wells at Lyons, Kansas, or the prospective wells near Carlsbad, New Mexico. This would be modified to meet existing conditions such as salt saturated slurry through the salt strata or added powdered silica in the zones which might exceed 230/sup 0/F at any time. A short epoxy plug was recommended at the top and bottom of the salt strata and a short Seal Ring plug at the base of any extensive water zones. Extensive water zones are not expected in the New Mexico area, however.

Deep Borehole Field Test Laboratory and Borehole Testing Strategy

Energy Technology Data Exchange (ETDEWEB)

Kuhlman, Kristopher L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Brady, Patrick V. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); MacKinnon, Robert J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Heath, Jason E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Herrick, Courtney G. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Jensen, Richard P. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Gardner, W. Payton [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Sevougian, S. David [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Bryan, Charles R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Jang, Je-Hun [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Stein, Emily R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Bauer, Stephen J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Daley, Tom [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Freifeld, Barry M. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Birkholzer, Jens [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Spane, Frank A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2016-09-19

Deep Borehole Disposal (DBD) of high-level radioactive wastes has been considered an option for geological isolation for many years (Hess et al. 1957). Recent advances in drilling technology have decreased costs and increased reliability for large-diameter (i.e., ≥50 cm [19.7”]) boreholes to depths of several kilometers (Beswick 2008; Beswick et al. 2014). These advances have therefore also increased the feasibility of the DBD concept (Brady et al. 2009; Cornwall 2015), and the current field test design will demonstrate the DBD concept and these advances. The US Department of Energy (DOE) Strategy for the Management and Disposal of Used Nuclear Fuel and High-Level Radioactive Waste (DOE 2013) specifically recommended developing a research and development plan for DBD. DOE sought input or expression of interest from States, local communities, individuals, private groups, academia, or any other stakeholders willing to host a Deep Borehole Field Test (DBFT). The DBFT includes drilling two boreholes nominally 200m [656’] apart to approximately 5 km [16,400’] total depth, in a region where crystalline basement is expected to begin at less than 2 km depth [6,560’]. The characterization borehole (CB) is the smaller-diameter borehole (i.e., 21.6 cm [8.5”] diameter at total depth), and will be drilled first. The geologic, hydrogeologic, geochemical, geomechanical and thermal testing will take place in the CB. The field test borehole (FTB) is the larger-diameter borehole (i.e., 43.2 cm [17”] diameter at total depth). Surface handling and borehole emplacement of test package will be demonstrated using the FTB to evaluate engineering feasibility and safety of disposal operations (SNL 2016).

Fuzzy systems modeling of in situ bioremediation of chlorinatedsolve n ts

Energy Technology Data Exchange (ETDEWEB)

Faybishenko, Boris; Hazen, Terry C.

2001-09-05

A large-scale vadose zone-groundwater bioremediationdemonstration was conducted at the Savannah River Site (SRS) by injectingseveral types of gases (ambient air, methane, and nitrous oxide andtriethyl phosphate mixtures) through a horizontal well in the groundwaterat a 175 ft depth. Simultaneously, soil gas was extracted through aparallel horizontal well in the vadose zone at a 80 ft depth Monitoringrevealed a wide range of spatial and temporal variations ofconcentrations of VOCs, enzymes, and biomass in groundwater and vadosezone monitoring boreholes over the field site. One of the powerful modernapproaches to analyze uncertain and imprecise data chemical data is basedon the use of methods of fuzzy systems modeling. Using fuzzy modeling weanalyzed the spatio-temporal TCE and PCE concentrations and methanotrophdensities in groundwater to assess the effectiveness of differentcampaigns of air stripping and bioremediation, and to determine the fuzzyrelationship between these compounds. Our analysis revealed some detailsabout the processes involved in remediation, which were not identified inthe previous studies of the SRS demonstration. We also identified somefuture directions for using fuzzy systems modeling, such as theevaluation of the mass balance of the vadose zone - groundwater system,and the development of fuzzy-ruled methods for optimization of managingremediation activities, predictions, and risk assessment.

Heterogeneity and Scaling in Geologic Media: Applications to Transport in the Vadose and Saturated Zones

Energy Technology Data Exchange (ETDEWEB)

Brown, Stephen R.

2003-06-01

Heterogeneity and Scaling in Geologic Media: Applications to Transport in the Vadose and Saturated Zones Stephen Brown, Gregory Boitnott, and Martin Smith New England Research In rocks and soils, the bulk geophysical and transport properties of the matrix and of fracture systems are determined by the juxtaposition of geometric features at many length scales. For sedimentary materials the length scales are: the pore scale (irregularities in grain surface roughness and cementation), the scale of grain packing faults (and the resulting correlated porosity structures), the scale dominated by sorting or winnowing due to depositional processes, and the scale of geomorphology at the time of deposition. We are studying the heterogeneity and anisotropy in geometry, permeability, and geophysical response from the pore (microscopic), laboratory (mesoscopic), and backyard field (macroscopic) scales. In turn these data are being described and synthesized for development of mathematical models. Eventually, we will perform parameter studies to explore these models in the context of transport in the vadose and saturated zones. We have developed a multi-probe physical properties scanner which allows for the mapping of geophysical properties on a slabbed sample or core. This device allows for detailed study of heterogeneity at those length scales most difficult to quantify using standard field and laboratory practices. The measurement head consists of a variety of probes designed to make local measurements of various properties, including: gas permeability, acoustic velocities (compressional and shear), complex electrical impedance (4 electrode, wide frequency coverage), and ultrasonic reflection (ultrasonic impedance and permeability). We can thus routinely generate detailed geophysical maps of a particular sample. With the exception of the acoustic velocity, we are testing and modifying these probes as necessary for use on soil samples. As a baseline study we have been

Numerical Simulation of Hydraulic Fracture Propagation Guided by Single Radial Boreholes

Directory of Open Access Journals (Sweden)

Tiankui Guo

2017-10-01

Full Text Available Conventional hydraulic fracturing is not effective in target oil development zones with available wellbores located in the azimuth of the non-maximum horizontal in-situ stress. To some extent, we think that the radial hydraulic jet drilling has the function of guiding hydraulic fracture propagation direction and promoting deep penetration, but this notion currently lacks an effective theoretical support for fracture propagation. In order to verify the technology, a 3D extended finite element numerical model of hydraulic fracturing promoted by the single radial borehole was established, and the influences of nine factors on propagation of hydraulic fracture guided by the single radial borehole were comprehensively analyzed. Moreover, the term ‘Guidance factor (Gf’ was introduced for the first time to effectively quantify the radial borehole guidance. The guidance of nine factors was evaluated through gray correlation analysis. The experimental results were consistent with the numerical simulation results to a certain extent. The study provides theoretical evidence for the artificial control technology of directional propagation of hydraulic fracture promoted by the single radial borehole, and it predicts the guidance effect of a single radial borehole on hydraulic fracture to a certain extent, which is helpful for planning well-completion and fracturing operation parameters in radial borehole-promoted hydraulic fracturing technology.

Sixth national outdoor action conference on aquifer restoration, ground water monitoring and geophysical methods

International Nuclear Information System (INIS)

Anon.

1992-01-01

The 1992 Outdoor Action Conference was comprised of three days of technical presentations, workshops, demonstrations, and an exhibition. The sessions were devoted to the following topics: Vadose Zone Monitoring Technology; Ground Water Monitoring Technology; Ground Water Sampling Technology; Soil and Ground Water Remediation; and Surface and Borehole Geophysics. The meeting was sponsored by the National Ground Water Association. These papers were published exactly as submitted, without technical and grammatical editing or peer review

Description and results of tracer tests conducted for a deep fracture zone within granitic rock at the Leuggern borehole

International Nuclear Information System (INIS)

Spane, F.A. jr.

1990-09-01

A tracer test program was planned at the Leuggern borehole, to provide hydrogeologic information concerning the fracture zone(s) intersected within the depth interval 1,634.9 - 1,688.9 m. The original design of the tracer-dilution test was to: establish a uniform tracer concentration within the test system, and then monitor (at ground surface) the decline of tracer concentration within the circulated test system fluid. Analysis of the tracer concentration decline pattern was expected to provide an estimate of the natural lateral flux and lateral hydraulic gradient for the isolated test interval. A later pump-back test was also designed to recover tracer that had been 'flushed' into the test section, during the previous closed-circulation period. Analysis of the tracer recovery pattern was expected to provide an estimate of the dispersivity within the intersected fracture system. Results obtained from 'arrival-time' information during the Eosin and Naphtionat injection/recovery phases indicate a downward vertical flow of approximately 195-225 ml/min in the isolated interval, from an analysis of the dilution levels of Uranin and Eosin during the injection/recovery periods, and review of field data, the top of the upper inflow zone was determined to be approximately 13 m below the top flow line and the bottom of the outflow zone to be approximately 3 to 5 meters above the bottom flow line. (author) 30 figs., tabs., 42 refs

Trial coring in LLRW trenches at Chalk River

International Nuclear Information System (INIS)

Donders, R.E.; Killey, R.W.D.; Franklin, K.J.; Strobel, G.S.

1996-11-01

As part of a program to better characterize the low-hazard radioactive waste managed by AECL at Chalk River Laboratories, coring techniques in waste trenches are being assessed. Trial coring has demonstrated that sampling in waste regions is possible, and that boreholes can be placed through the waste trenches. Such coring provides a valuable information-gathering technique. Information available from trench coring includes: trench cover depth, waste region depth, waste compaction level, and detailed stratigraphic data; soil moisture content and facility drainage performance; borehole gamma logs that indicate radiation levels in the region of the borehole; biochemical conditions in the waste regions, vadose zone, and groundwater; site specific information relevant to contaminant migration modelling or remedial actions; information on contaminant releases and inventories. Boreholes through the trenches can also provide a means for early detection of potential contaminant releases. (author). 4 refs., 4 tabs., 4 figs

Drilling and the associated borehole measurements of the pilot hole ONK-PH2

International Nuclear Information System (INIS)

Oehberg, A.; Aaltonen, I.; Kemppainen, K.; Mattila, J.; Heikkinen, E.; Lahti, M.; Pussinen, V.; Niemonen, J.; Paaso, N.; Rouhiainen, P.

2005-11-01

The construction of the ONKALO access tunnel started in September 2004 at Olkiluoto. Most of the investigations related to the construction of the access tunnel aim to ensure successful excavations, reinforcement and sealing. Pilot holes are boreholes, which are core drilled along the tunnel profile. The length of the pilot holes typically varies from several tens of metres to a couple of hundred metres. The pilot holes will mostly aim to confirm the quality of the rock mass for tunnel construction, and in particular at identifying water conductive fractured zones and at providing information that could result in modifications of the existing construction plans. The pilot hole ONK-PH2 was drilled in December 2004. The length of the borehole is about 122 metres. The aim during the drilling work was to orientate core samples as much as possible. The deviation of the borehole was measured during and after the drilling phase. Electric conductivity was measured from the collected returning water samples. Logging of the core samples included the following parameters: lithology, foliation, fracturing, fracture frequency, RQD, fractured zones, core loss and weathering. The rock mechanical logging was based on Q-classification. The tests to determine rock strength and deformation properties were made with a Rock Tester-equipment. Difference Flow method was used for the determination of hydraulic conductivity and hydraulic head in fractures and fractured zones in the borehole. The overlapping i.e. the detailed flow logging mode was used. The flow logging was performed with 0.5 m section length and with 0.1 m depth increments. Geophysical borehole logging and optical imaging surveys of the pilot hole PH2 included the field work of all the surveys, the integration of the data as well as interpretation of the acoustic and borehole radar data. One of the objectives of the geochemical study was to get information of composition of ONKALO's groundwater before the construction will

Drilling and the associated borehole measurements of the pilot hole ONK-PH3

International Nuclear Information System (INIS)

Oehberg, A.; Heikkinen, E.; Hirvonen, H.; Kemppainen, K.; Majapuro, J.; Niemonen, J.; Poellaenen, J.; Rouhiainen, P.

2006-03-01

The construction of the ONKALO access tunnel started in September 2004 at Olkiluoto. Most of the investigations related to the construction of the access tunnel aim to ensure successful excavations, reinforcement and sealing. Pilot holes are boreholes, which are core drilled along the tunnel profile. The length of the pilot holes typically varies from several tens of metres to a couple of hundred metres. The pilot holes will mostly aim to confirm the quality of the rock mass for tunnel construction, and in particular at identifying water conductive fractured zones and at providing information that could result in modifications of the existing construction plans. The pilot hole ONK-PH3 was drilled in September 2005. The length of the borehole is 145.04 metres. The aim during the drilling work was to orientate core samples as much as possible. The deviation of the borehole was measured during and after the drilling phase. Electric conductivity was measured from the collected returning water samples. Logging of the core samples included the following parameters: lithology, foliation, fracturing, fracture frequency, RQD, fractured zones, core loss and weathering. The rock mechanical logging was based on Q-classification. The tests to determine rock strength and deformation properties were made with a Rock Tester-equipment. Difference Flow method was used for the determination of hydraulic conductivity in fractures and fractured zones in the borehole. The overlapping i.e. the detailed flow logging mode was used. The flow logging was performed with 0.5 m section length and with 0.1 m depth increments. Water loss tests (Lugeon tests) and a pressure build-up test were used to give background information for the grouting design. Geophysical borehole logging and optical imaging surveys of the pilot hole PH3 included the field work of all the surveys, the integration of the data as well as interpretation of the acoustic and borehole radar data. One of the objectives of the

Borehole geophysical investigations of Lavia deep testhole, Finland

International Nuclear Information System (INIS)

Saksa, Pauli

1985-02-01

According to the Goverment's decision in principle in 1983 Industrial Power Company Ltd (TVO) is making preparations for all the steps of final disposal of the spent fuel produced by its power plants. Before the actual site investigation phase, TVO drilled a deep borehole in Lavia, Western Finland. The borehole is used during 1984-85 for testing investigation techniques and methods used for bedrock characterization. Borehole geophysical loggings performed in Lavia consisted of galvanic electrical, transient electromagnetic, radiometric, temperature, seismic and magnetic msurements. This composite survey provided both lithological and structural information of rock mass. The neutron-neutron, density, natural gamma radiation and susceptibility methods characterized rock type. Fracturing and its type could be interpreted most effectively with resistivity, acoustic P-wave velocity and density logs. Temperature and tube-wave measurements revealed several fractured zones related to possible water flow in rock. Lavia investigations indicated that a high quality of instrumentation and careful calibration are necessary for site investigations. The large amount of log data also requires efficient data collection and processing systems both in the field and laboratory. (author)

Core drilling of deep borehole OL-KR46 at Olkiluoto in Eurajoki 2007

International Nuclear Information System (INIS)

Toropainen, V.

2007-09-01

granite. The average fracture frequency is 1.2 pcs/m in borehole OL-KR46 and 3.6 pcs/m in borehole OL-KR46B. The average RQD values were 98.3 % and 93.1 %. In borehole OL-KR46 eight fractured zones and in borehole OL-KR46B three fractured zones were penetrated during drilling work. (orig.)

Synthesis of borehole geophysical data at the Underground Research Laboratory, Manitoba, Canada

International Nuclear Information System (INIS)

Keys, W.S.

1984-07-01

A suite of borehole-geophysical logs, supported by core data, was used to describe the rock matrix and fractures in a granitic pluton near Lac du Bonnet, Manitoba, Canada. The site is being developed by Atomic Energy of Canada Limited, as an underground research laboratory to conduct geotechnical research and to validate predictive models as part of Canada's nuclear-fuel, waste-management program. However, the site is not planned to be used for waste disposal. Geophysical well logs were used to distinguish and correlate rock types and fractures between drill holes. Two significant fracture zones that are two of the major zones of ground-water movement at the site were identified by acoustic-televiewer logs. A new heat-pulse flowmeter provided repeatable measurements of very low-velocity, vertical flow in drill holes which enabled the identification of specific fractures that were transmitting water. Borehole gamma spectra showed that some fractures are enriched in uranium, and others may be depleted. This study demonstrates some of the advantages of synthesizing available borehole-geophysical logs at a site in fractured plutonic rocks and indicates how this information can contribute to an understanding of the geophysical conditions at the site

Remediation of Uranium in the Hanford Vadose Zone Using Ammonia Gas: FY 2010 Laboratory-Scale Experiments

Energy Technology Data Exchange (ETDEWEB)

Szecsody, James E.; Truex, Michael J.; Zhong, Lirong; Qafoku, Nikolla; Williams, Mark D.; McKinley, James P.; Wang, Zheming; Bargar, John; Faurie, Danielle K.; Resch, Charles T.; Phillips, Jerry L.

2010-12-01

This investigation is focused on refining an in situ technology for vadose zone remediation of uranium by the addition of ammonia (NH3) gas. Objectives are to: a) refine the technique of ammonia gas treatment of low water content sediments to minimize uranium mobility by changing uranium surface phases (or coat surface phases), b) identify the geochemical changes in uranium surface phases during ammonia gas treatment, c) identify broader geochemical changes that occur in sediment during ammonia gas treatment, and d) predict and test injection of ammonia gas for intermediate-scale systems to identify process interactions that occur at a larger scale and could impact field scale implementation.Overall, NH3 gas treatment of low-water content sediments appears quite effective at decreasing aqueous, adsorbed uranium concentrations. The NH3 gas treatment is also fairly effective for decreasing the mobility of U-carbonate coprecipitates, but shows mixed success for U present in Na-boltwoodite. There are some changes in U-carbonate surface phases that were identified by surface phase analysis, but no changes observed for Na-boltwoodite. It is likely that dissolution of sediment minerals (predominantly montmorillonite, muscovite, kaolinite) under the alkaline conditions created and subsequent precipitation as the pH returns to natural conditions coat some of the uranium surface phases, although a greater understanding of these processes is needed to predict the long term impact on uranium mobility. Injection of NH3 gas into sediments at low water content (1% to 16% water content) can effectively treat a large area without water addition, so there is little uranium mobilization (i.e., transport over cm or larger scale) during the injection phase.

Remediation of Uranium in the Hanford Vadose Zone Using Ammonia Gas: FY 2010 Laboratory-Scale Experiments

International Nuclear Information System (INIS)

Szecsody, James E.; Truex, Michael J.; Zhong, Lirong; Qafoku, Nikolla; Williams, Mark D.; McKinley, James P.; Wang, Zheming; Bargar, John; Faurie, Danielle K.; Resch, Charles T.; Phillips, Jerry L.

2010-01-01

This investigation is focused on refining an in situ technology for vadose zone remediation of uranium by the addition of ammonia (NH3) gas. Objectives are to: (a) refine the technique of ammonia gas treatment of low water content sediments to minimize uranium mobility by changing uranium surface phases (or coat surface phases), (b) identify the geochemical changes in uranium surface phases during ammonia gas treatment, (c) identify broader geochemical changes that occur in sediment during ammonia gas treatment, and (d) predict and test injection of ammonia gas for intermediate-scale systems to identify process interactions that occur at a larger scale and could impact field scale implementation. Overall, NH3 gas treatment of low-water content sediments appears quite effective at decreasing aqueous, adsorbed uranium concentrations. The NH3 gas treatment is also fairly effective for decreasing the mobility of U-carbonate coprecipitates, but shows mixed success for U present in Na-boltwoodite. There are some changes in U-carbonate surface phases that were identified by surface phase analysis, but no changes observed for Na-boltwoodite. It is likely that dissolution of sediment minerals (predominantly montmorillonite, muscovite, kaolinite) under the alkaline conditions created and subsequent precipitation as the pH returns to natural conditions coat some of the uranium surface phases, although a greater understanding of these processes is needed to predict the long term impact on uranium mobility. Injection of NH3 gas into sediments at low water content (1% to 16% water content) can effectively treat a large area without water addition, so there is little uranium mobilization (i.e., transport over cm or larger scale) during the injection phase.

Advective Removal of Intraparticle Uranium from Contaminated Vadose Zone Sediments, Hanford, USA

International Nuclear Information System (INIS)

Ilton, Eugene S.; Qafoku, Nikolla; Liu, Chongxuan; Moore, D. A.; Zachara, John M.

2008-01-01

A column study on U contaminated vadose zone sediments from the Hanford Site, WA, was performed in order to aid the development of a model for predicting U(VI) release rates under a dynamic flow regime and for variable geochemical conditions. The sediments of interest are adjacent to and below tank BX-102, part of the BX tank farm that contained high level liquid radioactive waste. Two sediments, with different U(VI) loadings and intraparticle large fracture vs. smaller fracture ratios, were reacted with three different solutions. The primary reservoir for U(VI) appears to be a micron-sized nanocrystalline Na-U-Si phase, possibly Na-boltwoodite, that nucleated and grew on plagioclase grains that line fractures within sand-sized granitic clasts. The solutions were all calcite saturated and in equilibrium with atmospheric CO2, where one solution was simply DI-water, the second was a synthetic ground water (SGW) with elevated Na, and the third was the same SGW but with both elevated Na and Si. The latter two solutions were employed, in part, to test the effect of saturation state on U(VI) release. For both sediments and all three electrolytes, there was an initial rapid release of U(VI) to the advecting solution followed by a plateau of low U(VI) concentration. U(VI) effluent concentration increased during subsequent stop flow (SF) events. The electrolytes with elevated Na and Si appreciably depressed U(VI) concentrations relative to DI water. The effluent data for both sediments and all three electrolytes was simulated reasonably well by a three domain model (the advecting fluid, fractures, and matrix) that coupled U(VI) dissolution rates, intraparticle U(VI) diffusion, and interparticle advective transport of U(VI); where key transport and dissolution processes had been parameterized in previous batch studies. For the calcite-saturated DI-water, U(VI) concentrations in the effluent remained far below saturation with respect to Na-boltwoodite and release of U(VI) to

Preliminary results of hydrologic testing of the Umtanum Basalt Fracture Zone at borehole RRL-2 (3,781 to 3,827 ft)

International Nuclear Information System (INIS)

Strait, S.R.; Spane, F.A. Jr.

1983-02-01

This report presents preliminary results and description of hydrologic test activities for the Umtanum Basalt Fracture Zone at Borehole RRL-2, within the test interval 3,781 to 3,827 feet. Hydrologic tests conducted include two short-term, constant discharge pumping tests and two slug tests. Preliminary results indicate an observed hydraulic head for the test interval of 406.7 feet above mean sea level. Transmissivity values determined from hydrologic tests performed range between 205 and 881 ft 2 /day. The best estimate of equivalent hydraulic conductivity, based on an effective test thickness of 6 feet, is 147 ft/day. 8 refs., 6 figs., 3 tabs

Summary of lithologic logging of new and existing boreholes at Yucca Mountain, Nevada, March 1994 to June 1994

International Nuclear Information System (INIS)

Geslin, J.K.; Moyer, T.C.

1995-01-01

This report summarizes lithologic logging of core from boreholes at Yucca Mountain, Nevada, conducted from March 1994 to June 1994. Units encountered during logging include Quaternary-Tertiary alluvium and colluvium, Tertiary Rainier Mesa Tuff, all units in the Tertiary Paintbrush Group, and Tertiary Calico Hills Formation. Logging results are presented in a table of contact depths for core from unsaturated zone neutron (UZN) boreholes and graphic lithologic logs for core from north ramp geology (NRG) boreholes

Analysis and Summary Report of Historical Dry Well Gamma Logs for the 241-B Tank Farm - 200 East

International Nuclear Information System (INIS)

SYDNOR, H.A.

2000-01-01

This report provides a summary of the gross gamma ray data for the 241-B Tank Farm and is intended to identify changes in the gamma activity of gamma-emitting radionuclide contaminants around each accessible borehole, and is not intended to provide interpretation of the data relative to vadose zone mechanics. Trends in data, as well as areas where additional information would be helpful in evaluating the unusual nature of some of the data, are discussed

A strategy to seal exploratory boreholes in unsaturated tuff; Yucca Mountain Site Characterization Project

Energy Technology Data Exchange (ETDEWEB)

Fernandez, J.A. [Sandia National Labs., Albuquerque, NM (United States); Case, J.B.; Givens, C.A.; Carney, B.C. [IT Corp., Albuquerque, NM (United States)

1994-04-01

This report presents a strategy for sealing exploratory boreholes associated with the Yucca Mountain Site Characterization Project. Over 500 existing and proposed boreholes have been considered in the development of this strategy, ranging from shallow (penetrating into alluvium only) to deep (penetrating into the groundwater table). Among the comprehensive list of recommendations are the following: Those boreholes within the potential repository boundary and penetrating through the potential repository horizon are the most significant boreholes from a performance standpoint and should be sealed. Shallow boreholes are comparatively insignificant and require only nominal sealing. The primary areas in which to place seals are away from high-temperature zones at a distance from the potential repository horizon in the Paintbrush nonwelded tuff and the upper portion of the Topopah Spring Member and in the tuffaceous beds of the Calico Hills Unit. Seals should be placed prior to waste emplacement. Performance goals for borehole seals both above and below the potential repository are proposed. Detailed construction information on the boreholes that could be used for future design specifications is provided along with a description of the environmental setting, i.e., the geology, hydrology, and the in situ and thermal stress states. A borehole classification scheme based on the condition of the borehole wall in different tuffaceous units is also proposed. In addition, calculations are presented to assess the significance of the boreholes acting as preferential pathways for the release of radionuclides. Design calculations are presented to answer the concerns of when, where, and how to seal. As part of the strategy development, available technologies to seal exploratory boreholes (including casing removal, borehole wall reconditioning, and seal emplacement) are reviewed.

Nuclear waste package design for the Vadose zone in tuff

International Nuclear Information System (INIS)

O'Neal, W.C.; Ballou, L.B.; Gregg, D.W.; Russell, E.W.

1984-02-01

This report presents an overview of the selection and analysis of conceptual waste package designs that will be used by the Nevada Nuclear Waste Storage Investigations (NNWSI) project for disposal of high-level nuclear waste (HLW) at the proposed Yucca Mountain, Nevada Site. The design requirements that the waste packages are required to meet are listed. Concept drawings for the reference designs and one alternative package design are shown. Four metal alloys; 304L SS, 321 SS, 316L SS and Incoloy 825 have been selected for candidate canister/overpack materials, and 1020 carbon steel has been selected as the reference metal for the borehole liners. A summary of the results of technical and economic analysis supporting the selection of the conceptual waste package designs is included. Post-closure containment and release rates are not discussed in this paper. 17 references, 2 figures, 2 tables

Role of Competitive Cation Exchange on Chromatographic Displacement of Cesium in the Vadose Zone beneath the Hanford S/SX Tank Farm

International Nuclear Information System (INIS)

Lichtner, Peter C.; Yabusaki, Steven B.; Pruess, Karsten; Steefel, Carl

2004-01-01

believed to have been released from the SX-108/SX-109 tanks. The calculations indicate that during the initial period of the tank leak when Cs + is associated with high Na + concentrations, there is little retardation of the Cs + plume. However, as time increases the Na + and Cs + profiles become chromatographically separated due to differences in their selectivity coefficients and dilution of the tank leak plume with infiltrating rainwater. Eventually the two species become separated spatially, and Cs + becomes highly retarded and remains essentially fixed in the sediments by cation exchange. For the 20 m Na + simulated tank leak, the sorbed Cs + profile is in close agreement with data obtained from the slant borehole and consistent with the estimated tank supernatant concentration. The simulations suggest that natural attenuation processes should result in strong fixation of Cs + in the vadose zone in spite of the release of high Na + concentrations during a tank leak event

Effects of the deviation characteristics of nuclear waste emplacement boreholes on borehole liner stresses

International Nuclear Information System (INIS)

Glowka, D.A.

1990-09-01

This report investigates the effects of borehole deviation on the useability of lined boreholes for the disposal of high-level nuclear waste at the proposed Yucca Mountain Repository in Nevada. Items that lead to constraints on borehole deviation include excessive stresses that could cause liner failure and possible binding of a waste container inside the liner during waste emplacement and retrieval operations. Liner stress models are developed for two general borehole configurations, one for boreholes drilled with a steerable bit and one for boreholes drilled with a non-steerable bit. Procedures are developed for calculating liner stresses that arise both during insertion of the liner into a borehole and during the thermal expansion process that follows waste emplacement. The effects of borehole curvature on the ability of the waste container to pass freely inside the liner without binding are also examined. Based on the results, specifications on borehole deviation allowances are developed for specific vertical and horizontal borehole configurations of current interest. 11 refs., 22 figs., 4 tabs

Borehole MET-1/04 near Metlika, between the External and Internal Dinarides (SE Slovenia

Directory of Open Access Journals (Sweden)

Marijan Poljak

2005-06-01

Full Text Available In the year 2004, a deep borehole MET/04 east of Metlika in Bela Krajina was drilled. It reached the depth of 841 meters. The aim of drilling was to catch thermal water that would be used for touristical purposes. The area where the borehole is located belongsto the transitional zone of the External to the Internal Dinarides. The first ones are characterized mainly by shallow water carbonate rocks of Mesozoic age, while the other ones are composed mainly of deep water clastic rocks also of Mesozoic age. Structurally,this zone consists of a series of the Dinaric, NW-SE oriented, thrusts along which the Internal Dinarides are thrusted over the External ones. The bore hole itself is located in the flysch sequence of Upper Cretaceous age that is deposed transgressivelly onto theUpper Jurassic limestone. The flysch, that is composed of conglomerate, breccia, calcarenite and marl, is drilled to 182,5 m of depth. Further, to the 275 of depth, there follow Lower Cretaceous limestones, that belong either to large olistolitic blocks in the base of the flysch series or to a tectonic block of the imbricated structure. To the bottom of the borehole, there follow mainly ref and perireefal limestones of Upper Jurassic age. The upper part of these is determined to be of Upper Malmian age, since the lower part couldbelong to Lower Malmian. In the borehole, two water bearing zones were determined. The first one is in the interval from 92,5 to 184, and the second one in the interval from 220 to 355 meters at the depth.

Core drilling of deep borehole OL-KR43 at Olkiluoto in Eurajoki 2006

Energy Technology Data Exchange (ETDEWEB)

Niinimaeki, R. [Suomen Malmi Oy, Espoo (Finland)

2006-12-15

, tonalitic-granodioritic- granitic gneiss and pegmatite granite. The average fracture frequency is 1.6 pes/m in borehole OL-KR43 and 1.5 pes/m in borehole OL-KR43B. The average RQD values were 96.2 % and 97.7 %. In borehole OL-KR43 24 fractured zones and in borehole OL-KR43B one fractured zone were penetrated during drilling work. (orig.)

Experimental assessment of borehole wall drilling damage in basaltic rocks

International Nuclear Information System (INIS)

Fuenkajorn, K.; Daemen, J.J.K.

1986-06-01

Ring tension tests, permeability tests, and microscopic fracture studies have been performed to investigate the borehole damage induced at low confining pressure by three drilling techniques (diamond, percussion and rotary). Specimens are drilled with three hole sizes (38, 76, and 102 mm diameter) in Pomona basalt and Grande basaltic andesite. The damaged zone is characterized in terms of fractures and fracture patterns around the hole, and in terms of tensile strength reduction of the rock around the holes. Experimental results show that the thickness of the damaged zone around the hole ranges from 0.0 to 1.7 mm. A larger drill bit induces more wall damage than does a smaller one. Different drilling techniques show different damage characteristics (intensity and distribution). Damage characteristics are governed not only by drilling parameters (bit size, weight on bit, rotational speed, diamond radius, and energy), but also by properties of the rock. The weaker rock tends to show more intense damage than does the stronger one. Cracks within grains or cleavage fractures are predominant in slightly coarser grained rock (larger than 0.5 mm grain size) while intergranular cracks are predominant in very fine grained rock (smaller than 0.01 mm grain size). The damaged zones play no significant role in the flow path around a borehole plug

Identification of flow paths and quantification of return flow volumes and timing at field scale

Science.gov (United States)

Claes, N.; Paige, G. B.; Parsekian, A.

2017-12-01

Flood irrigation, which constitutes a large part of agricultural water use, accounts for a significant amount of the water that is diverted from western streams. Return flow, the portion of the water applied to irrigated areas that returns to the stream, is important for maintaining base flows in streams and ecological function of riparian zones and wetlands hydrologically linked with streams. Prediction of timing and volumes of return flow during and after flood irrigation pose a challenge due to the heterogeneity of pedogenic and soil physical factors that influence vadose zone processes. In this study, we quantify volumes of return flow and potential pathways in the subsurface through a vadose zone flow model that is informed by both hydrological and geophysical observations in a Bayesian setting. We couple a two-dimensional vadose zone flow model through a Bayesian Markov Chain Monte Carlo approach with time lapse ERT, borehole NMR datasets that are collected during and after flood irrigation experiments, and soil physical lab analysis. The combination of both synthetic models and field observations leads to flow path identification and allows for quantification of volumes and timing and associated uncertainties of subsurface return that stems from flood irrigation. The quantification of the impact of soil heterogeneity enables us to translate these results to other sites and predict return flow under different soil physical settings. This is key when managing irrigation water resources and predictions of outcomes of different scenarios have to be evaluated.

Physicochemical quality of borehole water in Abonnema and its ...

African Journals Online (AJOL)

Physicochemical quality of borehole water in Abonnema and its public health importance. ... The result of the analysis showed that the pH values across the zones had a mean range of 6.2 + 0.2 to 6.8 + 0.4, while conductivity values for Briggs and Obonoma compounds were 47.8 and 50.6 μs/cm respectively. However, the ...

Borehole logging

International Nuclear Information System (INIS)

Olsen, H.

1995-01-01

Numerous ground water investigations have been accomplished by means of borehole logging. Borehole logging can be applied to establish new water recovery wells, to control the existing water producing wells and source areas and to estimate ground water quality. (EG)

Results of hydraulic tests at Gibson Dome No. 1, Elk Ridge No. 1, and E. J. Kubat boreholes, Paradox Basin, Utah

International Nuclear Information System (INIS)

Thackston, J.W.; Preslo, L.M.; Hoexter, D.E.; Donnelly, N.

1984-03-01

Hydraulic testing was conducted in three boreholes in southeastern Utah to provide a portion of the data needed to characterize the hydrogeology of the Elk Ridge and Gibson Dome areas of the western Paradox Basin, Utah. The tests at the E. J. Kubat borehole yielded representative values of transmissivity, hydraulic conductivity, storativity, and potentiometric levels of the Leadville Limestone. Testing at Elk Ridge No. 1 provided values of similar parameters for the combined thickness of the upper Honaker Trail, Elephant Canyon, and Cedar Mesa formations. Composite transmissivities of similar zones from these borehole tests compared closely with the results of testing at borehole GD-1. A comparison of results from lab tests on core with results of extensive borehole testing at GD-1 indicates that short-term drill stem tests in a single well can provide representative estimates of bulk transmissivities and hydraulic conductivities in this field area for test zones that have a hydraulic conductivity of greater than about 1 x 10 -7 cm/sec. However, lab tests produce more representative values of effective porosity and matrix permeability of individual strata. Results of lab tests and long-term borehole tests confirm that the lower Honaker Trail and upper Paradox formations have extremely low conductivities in the vicinity of the GD-1 borehole. The results of these tests were complete as of January 1981. 22 references, 29 figures, 5 tables

Metamorphic rocks in the deep boreholes near Maribor

Directory of Open Access Journals (Sweden)

Mirka Trajanova

2002-12-01

Full Text Available Six research-captive boreholes for thermal water passed through a pile of metamorphic rocks near Maribor (Eastern Slovenia that is on average about 1000 m thick. The succession of metamorphic rocks is characteristic for the Pohorje Mt. and eastern Kobansko region. In the area of the boreholes two tectonic zones are more pronounced: the upper one, at a depth of about 510 to 550 m at the contact of the Štelenska Gora and Phyllite formations and the deeper one at a depth of about 460 to 590 m, indicating the reverse fault junction of the Phyllite and Kobansko formations. They belong to the second andthe third thrust unit of the accretionary wedge formed at the collision of the European and African plates. Four Alpine nappe units are proven in the Slovenian part of the Eastern Alps.

Borehole radar survey at the granite quarry mine, Pocheon, Kyounggi province

Energy Technology Data Exchange (ETDEWEB)

Kim, Jung Ho; Cho, Seong Jun; Yi, Myeong Jong; Chung, Seung Hwan; Lee, Hee Il; Shin, In Chul [Korea Institute of Geology Mining and Materials, Taejon (Korea, Republic of)

1997-12-01

Borehole radar survey in combination with the reflection and tomography methods was conducted at the Donga granite quarry mine of Pocheon area in Kyounggi province. The purpose of radar survey in quarry mine is to delineate the inhomogeneities including fractures and to estimate the freshness of rock. 20 MHz was adopted as the central frequency for the radar reflection and tomography surveys for the longer distance of penetration. The reflection survey using the direction finding antenna was also conducted to get the information on the spatial orientation of reflectors. Besides the various kinds of radar borehole survey, two surface geophysical methods, dipole-dipole resistivity survey and ground penetrating radar, were also applied to delineate the hidden parts of geological structures which was confirmed by geological mapping. The reflection data processing package, RADPRO ver. 2.2, developed continuously through in this study, was used to process the borehole reflection radar data. The new programs to process radar reflection data using directional antenna were devised and used to calculate and image the orientation of reflectors. The major dip angle of fractured zones were determined from the radar reflection images. With the aid of direction finding antenna and the newly developed algorithm to image the orientation of reflectors, it was possible to get the three dimensional attitudes of reflectors. Detailed interpretation results of the surveyed area are included in this report. Through the interpretation of borehole reflection data using dipole and direction finding antenna, we could determine the orientation of the major fractured zone, the boundary of two mining areas. Many of hidden inhomogeneities were found by borehole radar methods. By the image of direction finding antenna, it was confirmed that nearly all of them were located at the outside of the planned mining area or were situated very deeply. Therefore, the surveyed area consists of very fresh and

Water and vapor transfer in vadose zone of Gobi desert and riparian in the hyper arid environment of Ejina, China

Science.gov (United States)

Du, C.; Yu, J.; Sun, F.; Liu, X.

2015-12-01

To reveal how water and vapor transfer in vadose zone affect evapotranspiration in Gobi desert and riparian in hyper arid region is important for understanding eco-hydrological process. Field studies and numerical simulations were imported to evaluate the water and vapor movement processes under non isothermal and lower water content conditions. The soil profiles (12 layers) in Gobi desert and riparian sites of Ejina were installed with sensors to monitor soil moisture and temperature for 1 year. The meteorological conditions and water table were measured by micro weather stations and mini-Divers respectively in the two sites. Soil properties, including particles composition, moisture, bulk density, water retention curve, and saturated hydraulic conductivity of two site soil profiles, was measured. The observations showed that soil temperatures for the two sites displayed large diurnal and seasonal fluctuations. Temperature gradients with depth resulted in a downward in summer and upward in winter and became driving force for thermal vapor movement. Soil moistures in Gobi desert site were very low and varied slowly with time. While the soil moistures in riparian site were complicated due to root distribution but water potentials remained uniform with time. The hydrus-1D was employed to simulate evapotranspiration processes. The simulation results showed the significant difference of evaporation rate in the Gobi desert and riparian sites.

Core drilling of deep borehole OL-KR39 at Olkiluoto in Eurajoki 2005

Energy Technology Data Exchange (ETDEWEB)

Niinimaeki, R. [Suomen Malmi Oy, Espoo (Finland)

2005-11-15

fracture type. The average fracture frequency is 1. 7 pes/m in borehole OL-KR39 and 3.5 pes/m in borehole OL-KR39B. The average RQD values were 96.3 % and 92.0 %. In borehole OL-KR39 18 fractured zones and in borehole OL-KR39B three fractured zones were penetrated during this drilling work. (orig.)

Core drilling of deep borehole OL-KR34 at Olkiluoto in Eurajoki 2005

Energy Technology Data Exchange (ETDEWEB)

Rautio, T. [Suomen Malmi Oy, Espoo (Finland)

2005-07-15

Posiva Oy submitted an application for the Decision in Principle to the Finnish Government in May 1999. A positive decision was made at the end of 2000 by the Government. The Finnish Parliament ratified the Decision in Principle on the final disposal facility for spent nuclear fuel at Olkiluoto, Eurajoki in May 2001. The decision makes it possible for Posiva to focus the confirming bedrock investigations at Olkiluoto, where in the next few years an underground rock characterisation facility, ONKALO, will be constructed. As a part of the investigations Suomen Malmi Oy (Smoy) core drilled 100.07 m deep borehole with a diameter of 75.7 mm at Olkiluoto in April 2005. This borehole was aimed to get additional information of the quality of bedrock and the anomalous part of the bedrock and quality and the location of the fractured zones R19A and R19B. The identification number of the borehole is OL-KR34. A set of monitoring measurements and samplings from the drilling and returning water was carried out during the drilling. Both the volume and the electric conductivity of the drilling water and the returning water were recorded. The drill rig was computer controlled and during drilling the computer recorded information about drilling parameters. The objective of all measurements was to obtain more information about bedrock and groundwater properties. Sodium fluorescein was used as a label agent in the drilling water. The volume of the used drilling water was about 37m{sup 3} and the measured volume of the returning water was about 18m{sup 3} in borehole OL-KR34. The deviation of the borehole was measured with the deviation measuring instruments EMS and Maxibor. The results of the Maxibor measurements indicate that borehole OLKR34 deviates 0.84 m right and 0.15 m up at the borehole depth of 99 m. Uniaxial compressive strength, Young's Modulus and Poisson' s ratio were measured from the core samples. The average uniaxial compressive strength is about 142 MPa, the

Core drilling of deep borehole OL-KR36 at Olkiluoto in Eurajoki 2005

Energy Technology Data Exchange (ETDEWEB)

Niinimaeki, R.; Rautio, T. [Suomen Malmi Oy, Espoo (Finland)

2005-07-15

Posiva Oy submitted an application for the Decision in Principle to the Finnish Government in May 1999. A positive decision was made at the end of 2000 by the Government. The Finnish Parliament ratified the Decision in Principle on the final disposal facility for spent nuclear fuel at Olkiluoto, Eurajoki in May 2001. The decision makes it possible for Posiva to focus the confirming bedrock investigations at Olkiluoto, where in the next few years an underground rock characterisation facility, ONKALO, will be constructed. As a part of the investigations Suomen Malmi Oy (Smoy) core drilled 205.17 m deep borehole with a diameter of 75.7 mm at Olkiluoto in May 2005. This borehole was aimed to get additional information of the quality of bedrock and the anomalous part of the bedrock and quality and the location of the fractured zones R19A and R19B. The identification number of the borehole is OL-KR36. A set of monitoring measurements and samplings from the drilling and returning water was carried out during the drilling. Both the volume and the electric conductivity of the drilling water and the returning water were recorded. The drill rig was computer controlled and during drilling the computer recorded information about drilling measurements. The objective of all these measurements was to obtain more information about bedrock and groundwater properties. Sodium fluorescein was used as a label agent in the drilling water. The volume of the used drilling water was about 117 m{sup 3} and the measured volume of the returning water was about 51m{sup 3} in borehole OL-KR36. The deviation of the borehole was measured with the deviation measuring instruments EMS and Maxibor. The results of the Maxibor measurements indicate that borehole OL-KR36 deviates 10.34 m left and 7.11 m up at the borehole depth of 204 m. Uniaxial compressive strength, Young's Modulus and Poisson' s ratio were measured from the core samples. The average uniaxial compressive strength is about 126

Core drilling of deep borehole OL-KR35 at Olkiluoto in Eurajoki 2005

Energy Technology Data Exchange (ETDEWEB)

Rautio, T. [Suomen Malmi Oy, Espoo (Finland)

2005-07-15

Posiva Oy submitted an application for the Decision in Principle to the Finnish Government in May 1999. A positive decision was made at the end of 2000 by the Government. The Finnish Parliament ratified the Decision in Principle on the final disposal facility for spent nuclear fuel at Olkiluoto, Eurajoki in May 2001. The decision makes it possible for Posiva to focus the confirming bedrock investigations at Olkiluoto, where in the next few years an underground rock characterisation facility, ONKALO, will be constructed. As a part of the investigations Suomen Malmi Oy (Smoy) core drilled 100.87 m deep borehole with a diameter of 75.7 mm at Olkiluoto in May 2005. This borehole was aimed to get additional information of the quality of bedrock and the anomalous part of the bedrock and quality and the location of the fractured zones R19A and R19B. The identification number of the borehole is OL-KR35. A set of monitoring measurements and samplings from the drilling and returning water was carried out during the drilling. Both the volume and the electric conductivity of the drilling water and the returning water were recorded. The drill rig was computer controlled and during drilling the computer recorded information about drilling parameters. The objective of all measurements was to obtain more information about bedrock and groundwater properties. Sodium fluorescein was used as a label agent in the drilling water. The volume of the used drilling water was about 53 m{sup 3} and the measured volume of the returning water was about 25 m{sup 3} in borehole OL-KR35. The deviation of the borehole was measured with the deviation measuring instruments EMS and Maxibor. The results of the Maxibor measurements indicate that borehole OL-KR35 deviates 0.49 m right and 0.30 m up at the borehole depth of 99 m. Uniaxial compressive strength, Young's Modulus and Poisson' s ratio were measured from the core samples. The average uniaxial compressive strength is about 90 MPa, the

Core drilling of deep borehole OL-KR39 at Olkiluoto in Eurajoki 2005

International Nuclear Information System (INIS)

Niinimaeki, R.

2005-11-01

frequency is 1. 7 pes/m in borehole OL-KR39 and 3.5 pes/m in borehole OL-KR39B. The average RQD values were 96.3 % and 92.0 %. In borehole OL-KR39 18 fractured zones and in borehole OL-KR39B three fractured zones were penetrated during this drilling work. (orig.)

Basalt features observed in outcrops, cores, borehole video imagery and geophysical logs, and basalt hydrogeologic study at the Idaho National Engineering Laboratory, Eastern Idaho

International Nuclear Information System (INIS)

Bennecke, W.M.

1996-10-01

A study was undertaken to examine permeable zones identified in boreholes open to the underlying basalt and to describe the vertical cross flows present in the boreholes. To understand the permeable zones in the boreholes detailed descriptions and measurements of three outcrops in the Snake River Plain, three cores at the Idaho Chemical Processing Plant (ICPP) at the INEL, and over fifty borehole TV logs from the INEL were carried out. Based on the observations made on the three outcrops an idealized basalt lava flow model was generated that used a set of nomenclature that would be standard for the basalt lava flows studied. An upper vesicular zone, a sometimes absent columnar zone, central zone, and lower vesicular zone make up the basalt lava flow model. The overall distinction between the different zones are based on the vesicle shape size, vesicularity, and fractures present. The results of the studies also indicated that the basalt lava flows at the INEL are distal to medial facies pahoehoe lava flows with close fitting contacts. The most permeable zones identified in these basalts are fractured vesiculated portions of the top of the lava flow, the columnar areas, and basalt-flow contacts in order of importance. This was determined from impeller flowmeter logging at the INEL. Having this information a detailed stratigraphy of individual basalt lava flows and the corresponding permeable units were generated. From this it was concluded that groundwater flow at the ICPP prefers to travel along thin basalt lava flows or flow-units. Flow direction and velocity of intrawell flows detected by flowmeter is controlled by a nearby pumping well

Borehole radar and BIPS investigations in boreholes at the Boda area

Energy Technology Data Exchange (ETDEWEB)

Carlsten, S.; Straahle, A. [GEOSIGMA AB, Uppsala (Sweden)

2000-12-01

As part of the studies conducted in the Boda area, measurements with borehole radar, borehole TV (BIPS) and deviation measurements were performed during May 2000. The investigations were carried out in four percussion-drilled boreholes with a total length of 514 m. Two boreholes are vertical and two are directed into and below the cave area. The BIPS measurement showed the presence of 14 open fractures. Largest apparent aperture width of open fractures was 133 mm. In the lowest part in boreholes 2, 3, and 4, particles in suspension deteriorated the visibility. BIPS has revealed a dominating subhorizontal fracture set and another striking NW to N-S with a dip close to vertical. Possible but very uncertain is a third fracture set striking NE and dipping steeply towards S. The open and partly open fractures forms an average block size 11 m wide and 6 m high, while the length of the block is uncertain. Of 98 borehole radar reflectors interpreted to intersect within BIPS-mapped sections, 90 were possible to combine with BIPS-mapped structures, i.e. 92% of the radar reflectors. The fractured rock around Boda is a shallow feature, since borehole radar and BIPS measurements shows no evidence of increased fracturing or the presence of caves at larger depth in the Boda area. The result indicates that the formation of the superficial fracture system (with caves included) at Boda in all probability is connected to glacial action, such as banking.

Borehole radar and BIPS investigations in boreholes at the Boda area

International Nuclear Information System (INIS)

Carlsten, S.; Straahle, A.

2000-12-01

As part of the studies conducted in the Boda area, measurements with borehole radar, borehole TV (BIPS) and deviation measurements were performed during May 2000. The investigations were carried out in four percussion-drilled boreholes with a total length of 514 m. Two boreholes are vertical and two are directed into and below the cave area. The BIPS measurement showed the presence of 14 open fractures. Largest apparent aperture width of open fractures was 133 mm. In the lowest part in boreholes 2, 3, and 4, particles in suspension deteriorated the visibility. BIPS has revealed a dominating subhorizontal fracture set and another striking NW to N-S with a dip close to vertical. Possible but very uncertain is a third fracture set striking NE and dipping steeply towards S. The open and partly open fractures forms an average block size 11 m wide and 6 m high, while the length of the block is uncertain. Of 98 borehole radar reflectors interpreted to intersect within BIPS-mapped sections, 90 were possible to combine with BIPS-mapped structures, i.e. 92% of the radar reflectors. The fractured rock around Boda is a shallow feature, since borehole radar and BIPS measurements shows no evidence of increased fracturing or the presence of caves at larger depth in the Boda area. The result indicates that the formation of the superficial fracture system (with caves included) at Boda in all probability is connected to glacial action, such as banking

Borehole sealing method and apparatus

International Nuclear Information System (INIS)

Hartley, J.N.; Jansen, G. Jr.

1977-01-01

A method and apparatus is described for sealing boreholes in the earth. The borehole is blocked at the sealing level, and a sealing apparatus capable of melting rock and earth is positioned in the borehole just above seal level. The apparatus is heated to rock-melting temperature and powdered rock or other sealing material is transported down the borehole to the apparatus where it is melted, pooling on the mechanical block and allowed to cool and solidify, sealing the hole. Any length of the borehole can be sealed by slowly raising the apparatus in the borehole while continuously supplying powdered rock to the apparatus to be melted and added to the top of the column of molten and cooling rock, forming a continuous borehole seal. The sealing apparatus consists of a heater capable of melting rock, including means for supplying power to the heater, means for transporting powdered rock down the borehole to the heater, means for cooling the apparatus and means for positioning the apparatus in the borehole. 5 claims, 1 figure

Application of radiometric core data in developing correlation index for insitu gamma log and disequilibrium status across exploratory boreholes: a case study in Wahkut Block of West Khasi Hills District, Meghalaya, India

International Nuclear Information System (INIS)

Kukreti, B.M.; Kumar, Pramod

2011-01-01

With the objective to affirm apparent Uranium ore zone grade/thickness with good confidence for non-coring and coring boreholes with poor core recovery, a systematic study in the mineralised coring boreholes between insitu measured gamma ray log and laboratory measured core assay has been carried out, in the sedimentary environment of Wahkut block, West Khasi Hills district of Meghalaya. This also helps in quantifying correlation index and U disequilibrium status across the drilled boreholes and to convert apparent eU 3 O 8 grade to ore reserve (U 3 O 8 ). Study area consist of 2 sq km having 33 coring and 39 non coring boreholes with cumulative drilled depth of about 11,000 mts. On this available database, grade thickness continuity of uranium ore zone, in coring boreholes was evaluated with the criteria of minimal ore zone thickness of 1.0 mts at 100 ppm eU 3 O 8 cut-off grade. The same criteria were also extended to the core assay of drilled core. A population of 19 such simultaneous qualifying zone (borehole log and core assay) meeting the set criteria from 17 coring boreholes (average core recovery > 90%) was drawn. Study results gave grade thickness continuity index of 0.93 between radiometric core assay and borehole log with moderately strong relationship. Disequilibrium status of apparent eU 3 O 8 grade in the borehole was examined using chemically checked U 3 O 8 (β/γ) (Having high degree uranium data confidence 91%) and Ra (e) plot, after getting complete core samples radiometric and spectral gamma analysed for 14 such boreholes. Equilibrium status on this population indicates, disequilibrium in favour of parent (0.90-1.78 range) having log normal distribution and skewed to the higher side of mean 1.37 disequilibrium factor. (author)

Soil-water flux in the southern Great Basin, United States: temporal and spatial variations over the last 120,000 years

International Nuclear Information System (INIS)

Tyler, S.W.; Chapman, J.B.; Conrad, S.H.; Hammermeister, D.P.; Blout, D.O.; Miller, J.J.; Sully, M.J.; Ginanni, J.M.

1996-01-01

The disposal of hazardous and radioactive waste in arid regions requires a thorough understanding of the occurrence of soil-water flux and recharge. Soil-water chemistry and isotopic data are presented from three deep vadose zone boreholes (> 230 m) at the Nevada Test Site, located in the Great Basin geographic province of the southwestern United States, to quantify soil-water flux and its relation to climate. The low water contents found in the soils significantly reduce the mixing of tracers in the subsurface and provide a unique opportunity to examine the role of climate variation on recharge in arid climates. Tracing techniques and core data are examined in this work to reconstruct the paleohydrologic conditions existing in the vadose zone well beyond the timescales typically investigated. Stable chloride and chlorine 36 profiles indicate that the soil waters deep in the vadose zone range in age from approximately 20,000 to 120,000 years. Secondary chloride bulges that are present in two of the three profiles support the concept of recharge occurring at or near the last two glacial maxima, when the climate of the area was considerably wetter and cooler. The stable isotopic composition of the soil water in the profiles is significantly more depleted in heavy isotopes than is modern precipitation, suggesting that recharge under the current climate is not occurring at this arid site. Past and present recharge appears to have been strongly controlled by surface topography, with increased incidence of recharge where runoff from the surrounding mountains may have been concentrated. The data obtained from this detailed drilling and sampling program shed new light on the behavior of water in thick vadose zones and, in particular, show the sensitivity of arid regions to the extreme variations in climate experienced by the region over the last two glacial maxima

Classification of lithological units based on geophysical borehole logging - data from the Stripa mine

International Nuclear Information System (INIS)

Triumf, C.A.

1992-06-01

At the Crosshole site, located at the 360 m level in the Stripa mine, six boreholes F1-F6 have been drilled in a fanlike fashion. To achieve further knowledge of the geological conditions in the rock volumes outside the major tectonized zones, a classification of the pseudo-lithology has been carried out using data from boreholes F3-F6. The analysis has been supported by determination of density and magnetic susceptibility on core samples from boreholes F1-F5. This study demonstrates that the bulk of the tectonically less disturbed rock, forming the matrix in a network of dominant tectonical features, can be considered as homogeneous according to the silicate density. Three volumes with deviating lithology have however been identified in more than one borehole. Furthermore narrow sections are encountered, showing mineralogical, and probably also, micro-structural deviations from the normal granite. These narrow sections are irregularly spread along the boreholes. Their irregular distribution and narrowness, prevents correlation between boreholes. The result of the lithology identification is displayed using a modified Briggs cube. The method used in this project is applicable in many stages of an investigation programme where different disciplines are co-operating and partly complex information must be passed between individuals. (au)

Identification of potential water-bearing zones by the use of borehole geophysics in the vicinity of Keystone Sanitation Superfund Site, Adams County, Pennsylvania and Carroll County, Maryland

Science.gov (United States)

Conger, Randall W.

1997-01-01

Between April 23, 1996, and June 21, 1996, the U.S. Environmental Protection Agency contracted Haliburton-NUS, Inc., to drill four clusters of three monitoring wells near the Keystone Sanitation Superfund Site. The purpose of the wells is to allow monitoring and sampling of shallow, intermediate, and deep waterbearing zones for the purpose of determining the horizontal and vertical distribution of any contaminated ground water migrating from the Keystone Site. Twelve monitoring wells, ranging in depth from 50 to 397.9 feet below land surface, were drilled in the vicinity of the Keystone Site. The U.S. Geological Survey conducted borehole-geophysical logging and determined, with geophysical logs and other available data, the ideal intervals to be screened in each well. Geophysical logs were run on four intermediate and four deep wells, and a caliper log only was run on shallow well CL-AD-173 (HN-1S). Interpretation of geophysical logs and existing data determined the placement of screens within each borehole.

Groundwater sampling and chemical characterisation of the Laxemar deep borehole KLX02

International Nuclear Information System (INIS)

Laaksoharju, M.; Skaarman, C.; Smellie, J.; Nilsson, A.C.

1995-02-01

The Laxemar deep borehole, KLX02 (1705 m depth), located close to the Aespoe Hard Rock Laboratory (HRL), has been investigated. Groundwater sampling was conducted on two occasions and using different methods. The first sampling was taken in the open borehole using the so-called Tube sampler; the second sampling carried out using the SKB-packer equipment to isolate pre-determined borehole sections. Groundwater compositions consist of two distinct groupings; one shallow to intermediate Sodium-Bicarbonate type (Na(Ca,K):HC 3 Cl(SO 4 )) to a depth of 1000 m, and the other of deep origin, a calcium-chloride type (Ca-Na(K):Cl-SO 4 (Br)), occurring below 1000 m. The deep brines contain up to 46000 mg of Cl per litre. The influence of borehole activities are seen in the tritium data which record significant tritium down to 1000 m, and even to 1420 m. Mixing modelling shows that water from the 1960's is the main source for this tritium. The high tritium values in the 1090-1096.2 m section are due to contamination of 1% shallow water from 1960 and 2% of modern shallow water. The upper 800 m of bedrock at Laxemar lies within a groundwater recharge area; the sub-vertical to moderate angled fracture zones facilitate groundwater circulation to considerable depths, at least to 800 m, thus accounting for some of the low saline brackish groundwaters in these conducting fracture zones. Below 1000 m the system is hydraulically and geochemically 'closed' such that highly saline brines exist in a near-stagnant environment. 30 refs, 22 figs, 8 tabs

Influence of Wetting and Mass Transfer Properties of Organic Chemical Mixtures in Vadose Zone Materials on Groundwater Contamination by Nonaqueous Phase Liquids

Energy Technology Data Exchange (ETDEWEB)

Charles J Werth; Albert J Valocchi, Hongkyu Yoon

2011-05-21

Previous studies have found that organic acids, organic bases, and detergent-like chemicals change surface wettability. The wastewater and NAPL mixtures discharged at the Hanford site contain such chemicals, and their proportions likely change over time due to reaction-facilitated aging. The specific objectives of this work were to (1) determine the effect of organic chemical mixtures on surface wettability, (2) determine the effect of organic chemical mixtures on CCl4 volatilization rates from NAPL, and (3) accurately determine the migration, entrapment, and volatilization of organic chemical mixtures. Five tasks were proposed to achieve the project objectives. These are to (1) prepare representative batches of fresh and aged NAPL-wastewater mixtures, (2) to measure interfacial tension, contact angle, and capillary pressure-saturation profiles for the same mixtures, (3) to measure interphase mass transfer rates for the same mixtures using micromodels, (4) to measure multiphase flow and interphase mass transfer in large flow cell experiments, all using the same mixtures, and (5) to modify the multiphase flow simulator STOMP in order to account for updated P-S and interphase mass transfer relationships, and to simulate the impact of CCl4 in the vadose zone on groundwater contamination. Results and findings from these tasks and summarized in the attached final report.

Nuclear-waste isolation in the unsaturated zone of arid regions

International Nuclear Information System (INIS)

Wollenberg, H.A.; Wang, J.S.Y.; Korbin, G.

1982-05-01

The vadose zone in arid regions is considered as a possible environment for geologic isolation of nuclear waste. There are several topographic and lithologic combinations in the vadose zone of arid regions that may lend themselves to waste isolation considerations. In some cases, topographic highs such as mesas and interbasin ranges - comprised of several rock types, may contain essentially dry or partially saturated conditions favorable for isolation. The adjacent basins, especially in the far western and southwestern US, may have no surface or subsurface hydrologic connections with systems ultimately leading to the ocean. Some rock types may have the favorable characteristics of very low permeability and contain appropriate minerals for the strong chemical retardation of radionuclides. Environments exhibiting these hydrologic and geochemical attributes are the areas underlain by tuffaceous rocks, relatively common in the Basin and Range geomorphic province. Adjacent valley areas, where tuffaceous debris makes up a significant component of valley fill alluvium, may also contain thick zones of unsaturated material, and as such also lend themselves to strong consideration as respository environments. This paper summarizes the aspects of nuclear waste isolation in unsaturated regimes in alluvial-filled valleys and tuffaceous rocks of the Basin and Range province

Assessment of vulnerability zones for ground water pollution using ...

Indian Academy of Sciences (India)

D Anantha Rao

2018-05-22

May 22, 2018 ... and should always be free from contamination. But, the .... net Recharge, Aquifer media, Soil media, Topo- graphy, Impact of vadose zone .... The Yamuna River flows along this strike-slip ..... of factors such as inter-granular porosity, fractur- ing and ... from the basin boundary in the south-western part (figure ...

Site characterization and validation - drift and borehole fracture data. Stage 1

International Nuclear Information System (INIS)

Gale, J.; Straahle, A.

1988-09-01

This report describes the procedures used in mapping fractures intersecting seven scanlines along the southern and eastern boundaries of the Site Characterization and Validation (SCV) site and the procedures used in logging and orienting the fractures intersecting the core from six 'boundary boreholes' that were drilled as part of the site characterization program for the SCV site at the 360 m level in the Stripa mine. Scanline mapping along the mine drifts provided a detailed description of the fracture geomentry on the boundaries of the SCV site. The cores from the boundary boreholes have been logged, reconstructed and oriented using a borehole Televiewer and a borehole TV camera and the true fracture orientations calcilated. This has provide additional data on the fracture geometry within the SCV site. The fractire data from both the scanlines and the core logging are presented in the appendices. In addition, an initial analysis has been completed of the fracture orientations, trace lengths and spacings. Based on the variation in fracture orientations over the SCV site, there are two strong subvertical fracture sets or or clusters and a poorly represented sub-horizontal fracture set. An empirical approach, based on the 'blind zone' concept has been used to correct for orientation bias and to predict the orientations of the fracture system that will be intersected by the C and D boreholes in stage III. (33 figs., 6 tabl., 19 refs.)

The use of radiometric-logging techniques to determine uranium grade in certain mineralised Karoo boreholes

International Nuclear Information System (INIS)

Corner, B.; De Beer, G.P.

1976-05-01

During the period September-October 1975, 22 mineralised boreholes in nine different Karoo uranium occurrences were logged radiometrically with the aim of determining to what accuracy the actual uranium grade could be predicted from the gamma logs. The true uranium grades of the mineralised zones logged were known from existing chemical analyses. The results showed that the uranium grades could be predicted to an accuracy of better than 10% through the use of gamma-logging equipment calibrated at Pelindaba, provided that the ore was in equilibrium and that little or no thorium was present. Disequilibrium is, however, prevalent in the Karoo, and in the holes logged it occurred by depletion of uranium relative to its gamma-emitting daughter products. Such effects were mostly confined to the zone above the water table, and it is concluded that for Karoo-type occurrences, the high radiometric background levels observed over extended distances in some boreholes were indicative of radon-gas buildup, and hence of disequilibrium. It is further concluded that radiometric borehole logging can largely replace chemical analyses in the determination of uranium grade for ore-reserve calculations, although chemical checks for disequilibrium would always be necessary [af

Sealing of investigation boreholes, Phase 4 - Final report

Energy Technology Data Exchange (ETDEWEB)

Pusch, Roland [Drawrite AB, Luleaa Technical University, Luleaa (Sweden); Ramqvist, Gunnar [El-Tekno AB, Figeholm (Sweden); Bockgaard, Niclas [Golder Associates, Goeteborg (Sweden); Ekman, Lennart [LE Geokonsult AB, Baelinge (Sweden)

2011-09-15

The report describes the outcome of Phase 4 of the project 'Sealing of investigation boreholes', which deals with 1) characterization and planning of borehole sealing, 2) performance and quality assessment, 3) sealing of large diameter holes, and 4) interaction of clay and concrete plugs. A specific goal was to find ways to characterize, plan and seal of boreholes so that their impact on the overall hydraulic performance of the repository rock can predicted and controlled. The work comprised selection of representative 'reference holes' at the Laxemar and Forsmark sites for development of a general programme for planning and simulating implementation of borehole plugging campaigns, considering also cost issues. A second aim was to define and quantify the role of seals in the reference holes for finding out how important sealing really is. A third was to test a practical way to seal large diameter boreholes and a fourth to find out how concrete matures and performs in contact with smectite clay. The study demonstrated, in conclusion, the need for developing techniques for preparing deep boreholes before lasting seals are installed in them, since poor sealing can short-circuit hydraulically important fracture zones intersected by the holes. The practically oriented sealing activities showed that the technique developed for tight sealing of large-diameter boreholes is practical and feasible. The issue of chemical stability was investigated by testing the performance and constitution of a plug consisting of CBI concrete in contact with smectite-rich seals for almost three years. This study showed that none of them underwent substantial degradation in this period of time, but chemical reactions and thereby generated changes in physical behaviour of the plug components had taken place, particularly in the clay. The rate of degradation is, however, not yet known. It was concluded from this study that it is suitable to carry out a corresponding