WorldWideScience

Sample records for sanitary sewer overflows

  1. DEP Reported Sanitary Sewer Overflows

    Data.gov (United States)

    Montgomery County of Maryland — Sanitary sewer overflows reported to the Department of Environmental Protection by the Washington Suburban Sanitary Commission or individuals in the County. Update...

  2. 76 FR 35215 - Notice of EPA Workshop on Sanitary Sewer Overflows and Peak Wet Weather Discharges

    Science.gov (United States)

    2011-06-16

    ... Pennsylvania Avenue, NW. FOR FURTHER INFORMATION CONTACT: For further information about this notice, contact... or e-mail: schaner.greg@epa.gov . SUPPLEMENTARY INFORMATION: I. Background Properly designed..., line breaks, sewer defects that allow storm water and groundwater to overload the system, lapses in...

  3. Locations of Combined Sewer Overflow Outfalls

    Data.gov (United States)

    U.S. Environmental Protection Agency — This data layer identifies the locations of Combined sewer overflow outfalls. Combined sewer systems are sewers that are designed to collect rainwater runoff,...

  4. Sanitary Sewer Systems and Association with Gastrointestinal Illness: A case crossover analysis of Massachusetts Data, 2006-2008

    Science.gov (United States)

    Sanitary sewer overflows (SSOs) occur when untreated sewage is discharged into water sources before reaching the treatment facility potentially contaminating them with gastrointestinal pathogens. Causes of SSOs include heavy rainfall and rupture/blockage of sewer lines. Few studi...

  5. [Pollutant source apportionment of combined sewer overflows using chemical mass balance method].

    Science.gov (United States)

    Dai, Mei-Hong; Li, Tian; Zhang, Wei

    2013-11-01

    Pollutant characteristics of surface runoff, sanitary sewage and sewer deposits from a combined sewer system in Shanghai were studied. It was confirmed that the content of Zn, NH4(+) -N, P, respectively in surface runoff, sanitary sewage and sewer deposits was specific and relatively stable based on contrasting pollutant characteristics of different sources. Three non-dimensional parameters-Zn/P, NH4(+) -N/Zn, P/K were proposed as characteristic index for surface runoff, sanitary sewage and sewer deposits. In order to find sources of pollutants in CSO, the application of chemical mass balance method was discussed: the average contributions to CSO were 42.8% for surface runoff, 12.2% for sanitary sewage, 23.8% for sewer deposits, and the results basically reflected the composition of CSO pollution. The research method and results can provide guidance for pollutant source apportionment of combined sewer overflows.

  6. Solids separation efficiency of combined sewer overflows.

    Science.gov (United States)

    Luyckx, G; Vaes, G; Berlamont, J

    2005-01-01

    The removal of sewer solids at combined sewer overflow locations depends on the flow patterns inside the overflow structure on the one hand and on the sediment characteristics on the other hand. Flow conditions can be described by the residence time distribution; sewer sediments can be characterised by their settling velocity distribution. The combination of both distributions leads to a dimensionless efficiency curve, which gives the removal efficiency as a function of the Hazen number. For field conditions this efficiency curve is mainly influenced by the settling velocity distribution of the sewer sediments and, as a consequence, nearly identical efficiency curves are found for different types of prototype CSO structure. For design purposes, a methodology using return frequency analysis is proposed.

  7. 40 CFR 35.2024 - Combined sewer overflows.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Combined sewer overflows. 35.2024... from the State allotment for correction of combined sewer overflows provided that the project is on the... impacts of the combined sewer overflows and otherwise meets the requirements of this subpart. The...

  8. Locations of Combined Sewer Overflow Outfalls - US EPA Region 3

    Data.gov (United States)

    U.S. Environmental Protection Agency — This data layer identifies the locations of Combined sewer overflow outfalls. Combined sewer systems are sewers that are designed to collect rainwater runoff,...

  9. Urban Runoff and Combined Sewer Overflow.

    Science.gov (United States)

    Field, Richard; Gardner, Bradford B.

    1978-01-01

    Presents a literature review of wastewater treatment, covering publications of 1976-77. This review includes areas such as: (1) urban runoff quality and quantity; (2) urban hydrology; (3) management practices; and (4) combined sewer overflows. A list of 140 references is also presented. (HM)

  10. Estimation of combined sewer overflow discharge

    DEFF Research Database (Denmark)

    Ahm, Malte; Thorndahl, Søren Liedtke; Nielsen, Jesper Ellerbæk;

    2016-01-01

    Combined sewer overflow (CSO) structures are constructed to effectively discharge excess water during heavy rainfall, to protect the urban drainage system from hydraulic overload. Consequently, most CSO structures are not constructed according to basic hydraulic principles for ideal measurement...... weirs. It can, therefore, be a challenge to quantify the discharges from CSOs. Quantification of CSO discharges are important in relation to the increased environmental awareness of the receiving water bodies. Furthermore, CSO discharge quantification is essential for closing the rainfall-runoff mass......-balance in combined sewer catchments. A closed mass-balance is an advantage for calibration of all urban drainage models based on mass-balance principles. This study presents three different software sensor concepts based on local water level sensors, which can be used to estimate CSO discharge volumes from hydraulic...

  11. Measuring Flow Reductions in a Combined Sewer System using Green Infrastructure - abstract

    Science.gov (United States)

    In 2009, the Louisville and Jefferson County Metropolitan Sewer District (MSD) submitted an Integrated Overflow Abatement Plan (IOAP) addressing combined sewer overflows (CSOs) and sanitary sewer overflows. Many of the solutions involve gray infrastructure, such as large, end-of...

  12. Using data from monitoring combined sewer overflows to assess, improve, and maintain combined sewer systems

    OpenAIRE

    Montserrat Royuela, Albert; Bosch, Ll.; Kiser, M.A.; Poch, Manuel; Corominas Tabares, Lluís

    2015-01-01

    Using low-cost sensors, data can be collected on the occurrence and duration of overflows in each combined sewer overflow (CSO) structure in a combined sewer system (CSS). The collection and analysis of real data can be used to assess, improve, and maintain CSSs in order to reduce the number and impact of overflows. The objective of this study was to develop a methodology to evaluate the performance of CSSs using low-cost monitoring. This methodology includes (1) assessing the capacity of a C...

  13. Modelling total suspended solids, E. coli and carbamazepine, a tracer of wastewater contamination from combined sewer overflows

    Science.gov (United States)

    Pongmala, Khemngeun; Autixier, Laurène; Madoux-Humery, Anne-Sophie; Fuamba, Musandji; Galarneau, Martine; Sauvé, Sébastien; Prévost, Michèle; Dorner, Sarah

    2015-12-01

    Urban source water protection requires knowledge of sources of fecal contamination upstream of drinking water intakes. Combined and sanitary sewer overflows (CSOs and SSOs) are primary sources of microbiological contamination and wastewater micropollutants (WWMPs) in urban water supplies. To quantify the impact of sewer overflows, predictive simulation models are required and have not been widely applied for microbial contaminants such as fecal indicator bacteria and pathogens in urban drainage networks. The objective of this study was to apply a simulation model to estimate the dynamics of three contaminants in sewer overflows - total suspended solids, Escherichia coli (E. coli) and carbamazepine, a WWMP. A mixed combined and pseudo-sanitary drainage network in Québec, Canada was studied and modelled for a total of 7 events for which water quality data were available. Model results were significantly correlated with field water quality data. The model confirmed that the contributions of E. coli from runoff and sewer deposits were minor and their dominant source was from sewage. In contrast, the main sources of total suspended solids were stormwater runoff and sewer resuspension. Given that it is not present in stormwater, carbamazepine was found to be a useful stable tracer of sewage contributions to total contaminant loads and also provided an indication of the fraction of total suspended solids originating from sewer deposits because of its similar response to increasing flowrates.

  14. HIGH-RATE DISINFECTION TECHNIQUES FOR COMBIND SEWER OVERFLOW

    Science.gov (United States)

    This paper presents high-rate disinfection technologies for combined sewer overflow (CSO). The high-rate disinfection technologies of interest are: chlorination/dechlorination, ultraviolet light irradiation (UV), chlorine dioxide (ClO2 ), ozone (O3), peracetic acid (CH3COOOH )...

  15. Using data from monitoring combined sewer overflows to assess, improve, and maintain combined sewer systems.

    Science.gov (United States)

    Montserrat, A; Bosch, Ll; Kiser, M A; Poch, M; Corominas, Ll

    2015-02-01

    Using low-cost sensors, data can be collected on the occurrence and duration of overflows in each combined sewer overflow (CSO) structure in a combined sewer system (CSS). The collection and analysis of real data can be used to assess, improve, and maintain CSSs in order to reduce the number and impact of overflows. The objective of this study was to develop a methodology to evaluate the performance of CSSs using low-cost monitoring. This methodology includes (1) assessing the capacity of a CSS using overflow duration and rain volume data, (2) characterizing the performance of CSO structures with statistics, (3) evaluating the compliance of a CSS with government guidelines, and (4) generating decision tree models to provide support to managers for making decisions about system maintenance. The methodology is demonstrated with a case study of a CSS in La Garriga, Spain. The rain volume breaking point from which CSO structures started to overflow ranged from 0.6 mm to 2.8 mm. The structures with the best and worst performance in terms of overflow (overflow probability, order, duration and CSO ranking) were characterized. Most of the obtained decision trees to predict overflows from rain data had accuracies ranging from 70% to 83%. The results obtained from the proposed methodology can greatly support managers and engineers dealing with real-world problems, improvements, and maintenance of CSSs.

  16. Reducing pathogens in combined sewer overflows using performic acid.

    Science.gov (United States)

    Tondera, Katharina; Klaer, Kassandra; Koch, Christoph; Hamza, Ibrahim Ahmed; Pinnekamp, Johannes

    2016-10-01

    Combined sewer overflows contribute significantly to pathogen loads in surface water. Some chemical disinfectants such as chlorine have proved to reduce the levels of microorganisms even in complex matrices such as wastewater in combined sewer systems; however, some of them release toxic by-products into water bodies and increase costs of plant maintenance and repair. In this study, we determined if performic acid (PFA) disinfection units can be operated at decentralized treatment facilities and reduce bacteria, viruses, and protozoan parasites in combined sewer overflows (CSOs). The PFA dosing unit at the inflow of a CSO storage tank dosed a fixed flow volume into the inflowing stormwater and, thus, concentrations varied between approximately 12-24mgl(-1). The results showed a reduction of most hygienically relevant bacteria with mean removal efficiencies of 1.8log10 for Aeromonas spp. and 3.1log10 for E. coli. For viruses, however, reduction was only observed for somatic coliphages with 2.7log10. In this setting, PFA does not seem to be suitable to remove e.g. protozoan parasites such as Giardia lamblia. In terms of operation, dosing the substance is uncritical in decentralized facilities, but the PFA needs too much time to react with pathogens after being dosed into the overflow of CSO storage tanks and before dilution with surface water in most facilities.

  17. Detention storage volume for combined sewer overflow into a river.

    Science.gov (United States)

    Temprano, J; Tejero, I

    2002-06-01

    This article discusses the storage volume needed in a combined sewer system tank in order to preserve the water quality. There are a lot of design criteria which do not take into account the conditions of the receiving water, and as a result are inappropriate. A model was used to simulate the performance of a theoretical combined sewer system where a tank was located downstream. Results were obtained from the overflows produced by the rain recorded in Santander (Spain) for 11 years, with several combinations of storage volume and treatment capacity in the wastewater treatment plant. Quality criteria were also proposed for faecal coliforms, BOD, and total nitrogen to evaluate the effects from the overflows in the river water quality. Equations have been obtained which relate the number of overflows, the storage volume and the treatment plant capacity. The bacteriological pollution, quantified by means of faecal coliforms, was the analytical parameter which produced the most adverse effects in the river, so that more storage volume is needed (45 to 180 m3 ha(-1) net) than with other simulated pollutants (5 to 50 m3 ha(-1) net for BOD, and less than 4 m3 ha(-1) net for the total nitrogen). The increase in the treatment plant's capacity, from two to three times the flow in dry weather, reduces the impact on the river water in a more effective way, allowing a reduction of up to 65% in the number of overflows rather than increasing the storage volume.

  18. Identification of in-sewer sources of organic solids contributing to combined sewer overflows.

    Science.gov (United States)

    Ahyerre, M; Chebbo, G

    2002-09-01

    Previous research has shown that combined sewer systems are the main source of particle and organic pollution during rainfall events contributing to combined sewer overflow. The aim of this article is to identify in an urban catchment area called "Le Marais", in the center of Paris, the types of sediments that are eroded and contribute to the pollution of combined sewer overflow. Three sediment types are considered: granular material found in the inverts of pipes, organic biofilms and organic sediment at the water bed interface, identified as an immobile layer in the "Le Marais" catchment area. The method used consist, firstly, of sampling and assessing the organic pollutant loads and metallic loads of the particles in each type of sediment. Then, the mass of each type of sediment is assessed. The mass and the characteristics of each type of sediment is finally compared to the mass and characteristics of the particles eroded in the catchment area, estimated by mass balances, in order to find the source of eroded particles. The only identified type of deposit that can contribute to combined sewer overflows is the organic layer. Indeed, the solids of this layer have mean and metallic loads that are of the same order of magnitude as the eroded particles. Moreover, the mass of the organic layer considered over different time scales is of the same order of magnitude as the eroded masses during rainfall events and an erosion experiment showed that the organic layer is actually eroded.

  19. A software-based sensor for combined sewer overflows.

    Science.gov (United States)

    Leonhardt, G; Fach, S; Engelhard, C; Kinzel, H; Rauch, W

    2012-01-01

    A new methodology for online estimation of excess flow from combined sewer overflow (CSO) structures based on simulation models is presented. If sufficient flow and water level data from the sewer system is available, no rainfall data are needed to run the model. An inverse rainfall-runoff model was developed to simulate net rainfall based on flow and water level data. Excess flow at all CSO structures in a catchment can then be simulated with a rainfall-runoff model. The method is applied to a case study and results show that the inverse rainfall-runoff model can be used instead of missing rain gauges. Online operation is ensured by software providing an interface to the SCADA-system of the operator and controlling the model. A water quality model could be included to simulate also pollutant concentrations in the excess flow.

  20. Critical velocity of floatables in combined sewer overflow (CSO) chambers.

    Science.gov (United States)

    Cigana, J; Lefebvre, G; Marche, C

    2001-01-01

    Although the efficiency of underflow baffles has never been clearly proven, these underflow baffles have gained in popularity over the last few years as a viable means to intercept floatables in Combined Sewer Overflows (CSOs). These pilot scale essays, performed in a 17.0 metres basin at various flowrates, show that a critical horizontal velocity (V(CR)) may develop in the overflow chamber. Whenever this critical velocity is exceeded, floatables that would normally rise to the surface are kept within the flow and never intercepted, thus rendering the underflow baffle ineffective. The equation relating the critical horizontal velocity to the vertical velocity is found to be: V(CR) = 16 w R(H) 1/6.

  1. Relationships between rainfall and Combined Sewer Overflow (CSO) occurrences

    Science.gov (United States)

    Mailhot, A.; Talbot, G.; Lavallée, B.

    2015-04-01

    Combined Sewer Overflow (CSO) has been recognized as a major environmental issue in many countries. In Canada, the proposed reinforcement of the CSO frequency regulations will result in new constraints on municipal development. Municipalities will have to demonstrate that new developments do not increase CSO frequency above a reference level based on historical CSO records. Governmental agencies will also have to define a framework to assess the impact of new developments on CSO frequency and the efficiency of the various proposed measures to maintain CSO frequency at its historic level. In such a context, it is important to correctly assess the average number of days with CSO and to define relationships between CSO frequency and rainfall characteristics. This paper investigates such relationships using available CSO and rainfall datasets for Quebec. CSO records for 4285 overflow structures (OS) were analyzed. A simple model based on rainfall thresholds was developed to forecast the occurrence of CSO on a given day based on daily rainfall values. The estimated probability of days with CSO have been used to estimate the rainfall threshold value at each OS by imposing that the probability of exceeding this rainfall value for a given day be equal to the estimated probability of days with CSO. The forecast skill of this model was assessed for 3437 OS using contingency tables. The statistical significance of the forecast skill could be assessed for 64.2% of these OS. The threshold model has demonstrated significant forecast skill for 91.3% of these OS confirming that for most OS a simple threshold model can be used to assess the occurrence of CSO.

  2. Treatment of combined sewer overflows using ferrate (VI).

    Science.gov (United States)

    Gandhi, Rohan; Ray, Ajay K; Sharma, Virender K; Nakhla, George

    2014-11-01

    This paper presents the results of a study conducted on the treatment of combined sewer overflows using ferrate (VI) [Fe (VI)]. At a Fe (VI) dose of 0.24 mg/L, total chemical oxygen demand (TCOD), soluble chemical oxygen demand (SCOD), total biochemical oxygen demand (TBOD5), soluble biochemical oxygen demand (SBOD5), total suspended solids (TSS), volatile suspended solids (VSS), total phosphorus (TP), total nitrogen (TN), and soluble TN removal efficiencies of 71, 75, 69, 68, 72, 83, 64, 38, and 36%, respectively, were achieved. Kinetic studies revealed that a contact time of only 15 minutes is sufficient to achieve secondary effluent criteria. An innovative technique of using primary sludge (PS) and thickened waste activated sludge as a source for the in situ synthesis of ferrate was developed. A comparative study of treatment efficiencies achieved by Fe (VI) generated from different sources was done. At 0.1 mg/L dose of Fe (VI) synthesized from PS, TCOD, SCOD, TSS, VSS, TP, and TN removal efficiencies of 60, 62, 63, 67, 30, and 25%, respectively, were achieved.

  3. Chemical pretreatment of combined sewer overflows for improved UV disinfection.

    Science.gov (United States)

    Gibson, J; Farnood, R; Seto, P

    2016-01-01

    The aim of this research was to better understand chemical pre-treatment of combined sewer overflows (CSOs) for subsequent ultraviolet (UV) disinfection. Approximately 200 jar tests were completed. Alum (Al2(S04)3·12H2O) resulted in a higher UV light transmission (UVT), and equivalent total suspended solids (TSS) removal, than ferric chloride (FeCl3). An alum dose of 20 mg/L increased the UVT of the raw CSO from 30 to 60% after settling. The addition of 100 mg/L of alum maximized UVT reaching approximately 85%. Flocculation did not increase UVT. However, it did improve the removal of TSS. Cationic polymers worked quickly compared with metal coagulants, but only reached a UVT of 60%. A high positive charge density on the polymer improved the removal of turbidity when compared with low charge, but did not affect UVT. If the goal is to maximise UVT, a very high alum dose may be preferred. If the goal is to minimize coagulant dose with moderate UV performance, cationic polymer at approximately 3 mg/L is recommended.

  4. Priority substances in combined sewer overflows: case study of the Paris sewer network.

    Science.gov (United States)

    Gasperi, J; Garnaud, S; Rocher, V; Moilleron, R

    2011-01-01

    This study was undertaken to supply data on both priority pollutant (PP) occurrence and concentrations in combined sewer overflows (CSOs). A single rain event was studied on 13 sites within the Paris sewer network. For each sample, a total of 66 substances, including metals, polycyclic aromatic hydrocarbons (PAHs), pesticides, organotins, volatile organic compounds, chlorobenzenes, phthalates and alkylphenols were analyzed. Of the 66 compounds analyzed in all, 40 PPs including 12 priority hazardous substances were detected in CSOs. As expected, most metals were present in all samples, reflecting their ubiquitous nature. Chlorobenzenes and most pesticides were never quantified above the limit of quantification, while the majority of the other organic pollutants, except DEHP (median concentration: 22 μg.l(-1)), were found to lie in the μg.l(-1) range. For the particular rain event studied, the pollutant loads discharged by CSOs were evaluated and then compared to pollutant loads conveyed by the Seine River. Under the hydraulic conditions considered and according to the estimations performed, this comparison suggests that CSOs are potentially significant local source of metals, PAHs and DEHP. Depending on the substance, the ratio between the CSO and Seine River loads varied from 0.5 to 26, underscoring the important local impact of CSOs at the scale of this storm for most pollutants.

  5. Sewer System Management Plan.

    Energy Technology Data Exchange (ETDEWEB)

    Holland, Robert C. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-08-01

    A Sewer System Management Plan (SSMP) is required by the State Water Resources Control Board (SWRCB) Order No. 2006-0003-DWQ Statewide General Waste Discharge Requirements (WDR) for Sanitary Sewer Systems (General Permit). DOE, National Nuclear Security Administration (NNSA), Sandia Field Office has filed a Notice of Intent to be covered under this General Permit. The General Permit requires a proactive approach to reduce the number and frequency of sanitary sewer overflows (SSOs) within the State. SSMPs must include provisions to provide proper and efficient management, operation, and maintenance of sanitary sewer systems and must contain a spill response plan.

  6. Combined sewer overflows to surface waters detected by the anthropogenic marker caffeine.

    Science.gov (United States)

    Buerge, Ignaz J; Poiger, Thomas; Müller, Markus D; Buser, Hans-Rudolf

    2006-07-01

    Continuous progress in wastewater treatment technology and the growing number of households connected to wastewater treatment plants (WWTPs) have generally resulted in decreased environmental loading of many pollutants. Nonetheless, further reduction of pollutant inputs is required to improve the quality of surface waters in densely populated areas. In this context, the relative contribution of combined sewer overflows as sources of wastewater-derived contaminants has attracted more and more attention, but the quantitative importance of these overflows has barely been investigated. In this study, caffeine was successfully used as a chemical marker to estimate the fraction of sewer overflows in the catchment area of lake Greifensee, Switzerland. Caffeine is a ubiquitous compound in raw, domestic wastewater with typical per capita loads of approximately 16 mg person(-1) d(-1). In WWTPs of the Greifensee region, caffeine is largely eliminated (>99%), resulting in much smaller loads of combined sewer overflows were the most likely source of caffeine. Using a mass balance approach, it was possible to determine the fraction of wastewater (in dry weather equivalents) discharged untreated to the receiving streams (up to 10%, annual mean, approximately 2-3%). The concept of caffeine as a marker for combined sewer overflows was then applied to estimate phosphorus inputs to Greifensee with untreated and treated wastewater (approximately 1.5 and 2.0 t P y(-1), respectively), which corresponded well with P inputs determined in a separate study based on hydraulic considerations. For compounds with high elimination in WWTPs such as phosphorus (96-98% in the Greifensee area), inputs from combined sewer overflows are thus of similar magnitude as inputs from treated wastewater. The study demonstrated that caffeine is a suitable marker for untreated wastewater (from combined sewer overflows, direct discharges, etc.), but its sensitivity depends on regional conditions and decreases

  7. Combined Sewer Overflow pretreatment with chemical coagulation and a particle settler for improved peracetic acid disinfection

    DEFF Research Database (Denmark)

    Chhetri, Ravi Kumar; Bonnerup, Arne; Andersen, Henrik Rasmus

    2016-01-01

    Full scale disinfection by peracetic acid (PAA) was achieved on Combined Sewer Overflow (CSO) water, which was pre-treated physically by a fast settling-filtration unit. Disinfection of untreated CSO water using PAA was compared to treatment using a particle separator (HydroSeparator®) and additi......Full scale disinfection by peracetic acid (PAA) was achieved on Combined Sewer Overflow (CSO) water, which was pre-treated physically by a fast settling-filtration unit. Disinfection of untreated CSO water using PAA was compared to treatment using a particle separator (Hydro...

  8. New Approach for Receiving Water Objectives for Overflows from Sewer Systems

    DEFF Research Database (Denmark)

    Larsen, Torben

    2000-01-01

    The paper describes the results of the work for the establishment of consistent objectives for storm overflows from sewer systems in respect to the physical conditions in streams and rivers in Denmark. First the result of a questionnaire is mentioned. Next some principles of the methods for formu......The paper describes the results of the work for the establishment of consistent objectives for storm overflows from sewer systems in respect to the physical conditions in streams and rivers in Denmark. First the result of a questionnaire is mentioned. Next some principles of the methods...

  9. New approach for receiving water objectives for overflows from sewer systems

    DEFF Research Database (Denmark)

    Larsen, Torben

    1999-01-01

    The paper describes the results of the work for the establishment of consistent objectives for storm overflows from sewer systems in respect to the physical conditions in streams and rivers in Denmark. First the result of a questionnaire is mentioned. Next some principles of the methods for formu......The paper describes the results of the work for the establishment of consistent objectives for storm overflows from sewer systems in respect to the physical conditions in streams and rivers in Denmark. First the result of a questionnaire is mentioned. Next some principles of the methods...

  10. Distribution of selected PCB congeners in the Babcock Street sewer district: a multimedia approach to identify PCB sources in combined sewer overflows (CSOs) discharging to the Buffalo River, New York.

    Science.gov (United States)

    Loganathan, B G; Irvine, K N; Kannan, K; Pragatheeswaran, V; Sajwan, K S

    1997-08-01

    To evaluate sources of PCBs in combined sewer overflows (CSOs) to the Buffalo River, New York, combined sewage, sanitary flow, atmospheric wet and dry depositions, and street dust samples were collected from the Babcock Street sewer district and analyzed. Total PCB concentrations (sum of the PCB congeners quantitated) in particulate and dissolved phases of sanitary flow were 101-269 ng g-1 dry weight and 50% of the total PCB load in street dust samples. PCB congener composition in the particulate phase of CSOs reflects the congener pattern of the street dusts. In this context, it can be suggested that the local contaminated street dusts are one of the potential sources of PCBs in CSOs, which is a source of PCBs to the Buffalo River.

  11. Modeling climate change impacts on combined sewer overflow using synthetic precipitation time series.

    Science.gov (United States)

    Bendel, David; Beck, Ferdinand; Dittmer, Ulrich

    2013-01-01

    In the presented study climate change impacts on combined sewer overflows (CSOs) in Baden-Wuerttemberg, Southern Germany, were assessed based on continuous long-term rainfall-runoff simulations. As input data, synthetic rainfall time series were used. The applied precipitation generator NiedSim-Klima accounts for climate change effects on precipitation patterns. Time series for the past (1961-1990) and future (2041-2050) were generated for various locations. Comparing the simulated CSO activity of both periods we observe significantly higher overflow frequencies for the future. Changes in overflow volume and overflow duration depend on the type of overflow structure. Both values will increase at simple CSO structures that merely divide the flow, whereas they will decrease when the CSO structure is combined with a storage tank. However, there is a wide variation between the results of different precipitation time series (representative for different locations).

  12. Laboratory and field investigation of chemical disinfection of combined sewer overflow in Copenhagen area

    DEFF Research Database (Denmark)

    Chhetri, Ravi Kumar; Thornberg, Dines; Berner, Jesper;

    We investigated the possibility to apply performic acid (PFA) and peracetic acid (PAA) for disinfection of combined sewer overflow (CSO) in existing CSO management infrastructures. The disinfection power of PFA and PAA to Escherichia coli (E. coli) and enterococcus were studied in batch scale...

  13. Chemical disinfection of combined sewer overflow waters using performic acid or peracetic acids

    DEFF Research Database (Denmark)

    Chhetri, Ravi Kumar; Thornberg, Dines; Berner, Jesper;

    2014-01-01

    We investigated the possibility of applying performic acid (PFA) and peracetic acid (PAA) for disinfection of combined sewer overflow (CSO) in existing CSO management infrastructures. The disinfection power of PFA and PAA towards Escherichia coli (E. coli) and Enterococcus was studied in batch...

  14. High-Rate Disinfection Techniques for Combined Sewer Overflow (Proceedings Paper)

    Science.gov (United States)

    This paper presents high-rate disinfection technologies for combined sewer overflow (CSO). The high-rate disinfection technologies of interest are: chlorination/dechlorination, ultraviolet light irradiation (UV), chlorine dioxide (ClO2 ), ozone (O3), peracetic acid (CH3COOOH ), a...

  15. Combined sewer overflows in urban areas - interpreting and comparing European CSO monitoring results

    NARCIS (Netherlands)

    Aarts, A.L.F.; Langeveld, J.G.; Ten Veldhuis, J.A.E.; Rietveld, L.C.

    2013-01-01

    Since the initiation of environmental legislation, monitoring campaigns have been done to estimate the characteristic pollutant concentrations of combined sewer overflow water. Such local campaigns are expensive due to the large number of events which should ideally be followed. This study focused o

  16. Assessment of pollutant load emission from combined sewer overflows based on the online monitoring.

    Science.gov (United States)

    Brzezińska, Agnieszka; Zawilski, Marek; Sakson, Grażyna

    2016-09-01

    Cities equipped with combined sewer systems discharge during wet weather a lot of pollutants into receiving waters by combined storm overflows (CSOs). According to the Polish legislation, CSOs should be activated no more than ten times per year, but in Lodz, most of the 18 existing CSOs operate much more frequently. To assess the pollutant load emitted by one of the existing CSOs, the sensors for measuring the concentration of total suspended solids (SOLITAX sc) and dissolved chemical oxygen demand (UVAS plus) installed in the overflow chamber as well as two flowmeters placed in the outflow sewer were used. In order to check the data from sensors, laboratory tests of combined wastewater quality were conducted simultaneously. For the analysis of the total pollutant load emitted from the overflow, the raw data was denoised using the Savitzky-Golay method. Comparing the load calculated from the analytical results to online smoothed measurements, negligible differences were found, which confirms the usefulness of applying the sensors in the combined sewer system. Online monitoring of the quantity and quality of wastewater emitted by the combined sewer overflows to water receivers, provides a considerable amount of data very useful for combined sewerage upgrading based on computer modelling, and allows for a significant reduction of laboratory analysis.

  17. Bacterial diversity impacts as a result of combined sewer overflow in a polluted waterway

    Directory of Open Access Journals (Sweden)

    O. Calderon

    2017-12-01

    Full Text Available Newtown Creek is an industrial waterway and former tidal wetland in New York City. It is one of the most polluted water bodies in the United States and was designated as a superfund site in 2010. For over a century, organic compounds, heavy metals, and other forms of industrial pollution have disrupted the creek’s environment. The creek is also impacted by discharges from twenty combined sewer overflow pipes, which may deposit raw sewage or partially treated wastewater directly into the creek during heavy or sustained rain events. Combined sewer overflow events and associated nutrient over-enrichment at the creek drive eutrophication and subsequent hypoxia. At the current study, three sites were sampled one week apart during a dry period and a wet period, where indication of a combined sewage overflow event could be detected. 16s rRNA high-throughput sequencing from these three sites collectively yielded over 1000 species of bacteria belonging to twenty-two classes. Based on these data, it is hypothesized that differences identified in the microbiome on wet versus dry days are as a result of combined sewage overflow, street runoff, and additional fluctuations in the creek’s environment associated with rain. It was found that after a combined sewer overflows event, the levels of Gamma Proteobacteria increased while the levels of Actinobacteria decreased. However, levels of bacteria stayed relatively unchanged at a site further away from combined sewer overflows discharge. Species found in Newtown Creek include pelagic, marine, human and animal pathogens, hydrocarbonoclastic, and other environmental microbes.

  18. Design of self-cleansing sanitary sewer systems with the use of flushing devices.

    Science.gov (United States)

    Goormans, T; Engelen, D; Bouteligier, R; Willems, P; Berlamont, J

    2009-01-01

    Many European countries tend to shift from constructing combined sewer systems to separate ones, in order to optimise wastewater treatment efficiency and reduce CSO impact on surface waters. An economic design minimises maintenance requirements by aiming at self-cleansing pipes. However, providing the necessary slopes for self-cleansing sanitary sewer pipes often is unfeasible in flat regions, resulting in an increased risk of loss of hydraulic capacity or blocking. To reduce these risks, flushing tanks can be installed in the sewer system. Where most other researchers contribute to a better understanding of the hydraulics of flushing, this paper rather tries to formulate a methodology to design and test flushing devices in sanitary sewer systems using standards and hydrodynamic simulations. Therefore, several aspects that require consideration when incorporating flushing devices into a sanitary sewer system are discussed. For instance, when flushing sanitary sewers the increase in discharge has to be explicitly considered. A Belgian case study is used to investigate the suitability of the developed methodology. Although the pipe slopes in the methodology are derived assuming uniform flow, the simulation results comply with it. Furthermore, pressurisation of the conduits due to multiple flushing waves remains within acceptable limits.

  19. Effects of combined-sewer overflows and urban runoff on the water quality of Fall Creek, Indianapolis, Indiana

    Science.gov (United States)

    Martin, J.D.

    1995-01-01

    In 1986, the U.S. Geological Survey and the Indianapolis Department of Public Works began a study to evaluate the effects of combined-sewer overflows and urban runoff discharging to Fall Geek on the White River. This report describes the effects of combined-sewer overflows and urban runoff on the water quality of Fall Creek during summer 1987 by comparing the water quality during base flow with that during storm runoff and by comparing water quality in the urbanized area with that in the less urbanized area upstream from the combined-sewer overflows. Data were collected at three streamflow-gaging stations located upstream from, downstream from, and in the middle of 27 combined-sewer overflows on Fall Creek. The most downstream station also was immediately downstream from the discharge of filter backwash from a water-treatment plant for public supply.

  20. EMISSION OF POLLUTANTS FROM COMBINED SEWER OVERFLOWS IN THE ASPECT OF THEIR IMPACT ON A RECEIVER

    Directory of Open Access Journals (Sweden)

    Agnieszka Brzezińska

    2016-06-01

    Full Text Available Increased efficiency of wastewater treatment highlights the role of combined sewer overflows in deterioration the quality of water receiver because pollutant loads discharged by them have a growing share in entire load discharged into a receiver. The article contains the results of the wastewater quality analyzes emitted into the receiver from the three studied combined sewer overflows of the city of Lodz. The results demonstrated a large variations in the pollutant concentration directed to the receiver during rain events. The possible impact of untreated wastewater emitted to the receiver is also presented. Apart from the pollution of the receiver, mainly by organic and nutrient substances, the microbiological contamination which is dangerous for people using the river as a recreation area and for animals that use a water receiver as a source of drinking water, should be taken into particular attention.

  1. Cumulative effects of fecal contamination from combined sewer overflows: Management for source water protection.

    Science.gov (United States)

    Jalliffier-Verne, Isabelle; Heniche, Mourad; Madoux-Humery, Anne-Sophie; Galarneau, Martine; Servais, Pierre; Prévost, Michèle; Dorner, Sarah

    2016-06-01

    The quality of a drinking water source depends largely on upstream contaminant discharges. Sewer overflows can have a large influence on downstream drinking water intakes as they discharge untreated or partially treated wastewaters that may be contaminated with pathogens. This study focuses on the quantification of Escherichia coli discharges from combined sewer overflows (CSOs) and the dispersion and diffusion in receiving waters in order to prioritize actions for source water protection. E. coli concentrations from CSOs were estimated from monitoring data at a series of overflow structures and then applied to the 42 active overflow structures between 2009 and 2012 using a simple relationship based upon the population within the drainage network. From these estimates, a transport-dispersion model was calibrated with data from a monitoring program from both overflow structures and downstream drinking water intakes. The model was validated with 15 extreme events such as a large number of overflows (n > 8) or high concentrations at drinking water intakes. Model results demonstrated the importance of the cumulative effects of CSOs on the degradation of water quality downstream. However, permits are typically issued on a discharge point basis and do not consider cumulative effects. Source water protection plans must consider the cumulative effects of discharges and their concentrations because the simultaneous discharge of multiple overflows can lead to elevated E. coli concentrations at a drinking water intake. In addition, some CSOs have a disproportionate impact on peak concentrations at drinking water intakes. As such, it is recommended that the management of CSOs move away from frequency based permitting at the discharge point to focus on the development of comprehensive strategies to reduce cumulative and peak discharges from CSOs upstream of drinking water intakes.

  2. Assessment of pollutant load emission from combined sewer overflows based on the online monitoring

    OpenAIRE

    Brzezińska, Agnieszka; Zawilski, Marek; Sakson, Grażyna

    2016-01-01

    Cities equipped with combined sewer systems discharge during wet weather a lot of pollutants into receiving waters by combined storm overflows (CSOs). According to the Polish legislation, CSOs should be activated no more than ten times per year, but in Lodz, most of the 18 existing CSOs operate much more frequently. To assess the pollutant load emitted by one of the existing CSOs, the sensors for measuring the concentration of total suspended solids (SOLITAX sc) and dissolved chemical oxygen ...

  3. Effects of combined sewer overflows on a periurban stream ecosystem: Methodological approach

    OpenAIRE

    Breil, P.; Lafont, M.; Vivier, A.; Namour, P.; Schmitt, L.

    2007-01-01

    International audience; Here we develop from a long term field experiment an assessment method of interstitial fauna resilience to combined sewer overflows (CSOs) effect. We address the case of small water courses for which the ratio of CSOs to natural flow can be 1 to much more. Biotic material was collected in the benthic and hyporheic layers. Biotic material focussed mainly on oligocheates species whose diversity, species category and abundance are resumed into metrics, called functional t...

  4. Water Quality of Combined Sewer Overflows, Stormwater, and Streams, Omaha, Nebraska, 2006-07

    Science.gov (United States)

    Vogel, Jason R.; Frankforter, Jill D.; Rus, David L.; Hobza, Christopher M.; Moser, Matthew T.

    2009-01-01

    The U.S. Geological Survey, in cooperation with the City of Omaha, investigated the water quality of combined sewer overflows, stormwater, and streams in the Omaha, Nebraska, area by collecting and analyzing 1,175 water samples from August 2006 through October 2007. The study area included the drainage area of Papillion Creek at Capeheart Road near Bellevue, Nebraska, which encompasses the tributary drainages of the Big and Little Papillion Creeks and Cole Creek, along with the Missouri River reach that is adjacent to Omaha. Of the 101 constituents analyzed during the study, 100 were detected in at least 1 sample during the study. Spatial and seasonal comparisons were completed for environmental samples. Measured concentrations in stream samples were compared to water-quality criteria for pollutants of concern. Finally, the mass loads of water-quality constituents in the combined sewer overflow discharges, stormwater outfalls, and streams were computed and compared. The results of the study indicate that combined sewer overflow and stormwater discharges are affecting the water quality of the streams in the Omaha area. At the Papillion Creek Basin sites, Escherichia coli densities were greater than 126 units per 100 milliliters in 99 percent of the samples (212 of 213 samples analyzed for Escherichia coli) collected during the recreational-use season from May through September (in 2006 and 2007). Escherichia coli densities in 76 percent of Missouri River samples (39 of 51 samples) were greater than 126 units per 100 milliliters in samples collected from May through September (in 2006 and 2007). None of the constituents with human health criteria for consumption of water, fish, and other aquatic organisms were detected at levels greater than the criteria in any of the samples collected during this study. Total phosphorus concentrations in water samples collected in the Papillion Creek Basin were in excess of the U.S. Environmental Protection Agency's proposed

  5. Calculation of Intercepted Volume of Sewer Overflows: a Model for Control of Nonpoint Pollution Sources in Urban Areas

    Institute of Scientific and Technical Information of China (English)

    S. C. Choi; D. I. Jung; C. H. Won; J. M. Rim

    2006-01-01

    The authors discovered large differences in the characteristics of overflows by the calculation of 1) intercepting volume of overflows for sewer systems using SWMM model which takes into consideration the runoff and pollutants from rainfalls and 2) the intercepted volume in the total flow at an investigation site. The intercepting rate at the investigation point of CSOs showed higher values than the SSDs. Based on the modeling of the receiving water quality after calculating the intercepting amount of overflows by considering the characteristics of outflows for a proper management of the overflow of sewer systems with rainfalls, it is clear that the BOD decreased by 82.9%-94.0% for the discharge after intercepting a specific amount of flows compared to the discharge from unprocessed overflows.

  6. Reducing pathogens in combined sewer overflows using ozonation or UV irradiation.

    Science.gov (United States)

    Tondera, Katharina; Klaer, Kassandra; Gebhardt, Jens; Wingender, Jost; Koch, Christoph; Horstkott, Marina; Strathmann, Martin; Jurzik, Lars; Hamza, Ibrahim Ahmed; Pinnekamp, Johannes

    2015-11-01

    Fecal contamination of water resources is a major public health concern in densely populated areas since these water bodies are used for drinking water production or recreational purposes. A main source of this contamination originates from combined sewer overflows (CSOs) in regions with combined sewer systems. Thus, the treatment of CSO discharges is urgent. In this study, we explored whether ozonation or UV irradiation can efficiently reduce pathogenic bacteria, viruses, and protozoan parasites in CSOs. Experiments were carried out in parallel settings at the outflow of a stormwater settling tank in the Ruhr area, Germany. The results showed that both techniques reduce most hygienically relevant bacteria, parasites and viruses. Under the conditions tested, ozonation yielded lower outflow values for the majority of the tested parameters.

  7. [Study on the characteristics of combined sewer overflow from the high density residential area in Shanghai].

    Science.gov (United States)

    Li, He; Li, Tian

    2006-08-01

    The urban non-point pollution has become main pollution resource of urban water bodies of Shanghai. Character of combined sewer overflow from watershed SA in Shanghai was studied, and the correlation of influence factors to the EMCs of overflows was discussed. It is found that the EMCs of COD, BOD, SS, NH3-N, TN, TP are 614 mg/L, 208.5 mg/L, 684 mg/L, 17.6 mg/L, 29.8 mg/L, 3.0 mg/L respectively, and the values obtained herein are much higher than the documented data from other countries. From the probability plot of the EMCs, it is found that the BOD has the best fitness for lognormal distribution; and correlation between the EMCs of COD, SS and the ratio of antecedent dry weather time to rain duration is quite good.

  8. Laboratory and field investigation of chemical disinfection of combined sewer overflow in Copenhagen area

    DEFF Research Database (Denmark)

    Chhetri, Ravi Kumar; Thornberg, Dines; Berner, Jesper

    We investigated the possibility to apply performic acid (PFA) and peracetic acid (PAA) for disinfection of combined sewer overflow (CSO) in existing CSO management infrastructures. The disinfection power of PFA and PAA to Escherichia coli (E. coli) and enterococcus were studied in batch scale...... and pre-field experiment. There were no toxicological effect measured by Vibrio fischeri when CSO was disinfected with PFA, slight toxicological effect was observed on CSO disinfected with PAA. When the design for PFA based disinfection was applied to CSO collected from an authentic event. Disinfection...

  9. Probabilistic modelling of combined sewer overflow using the First Order Reliability Method

    DEFF Research Database (Denmark)

    Thorndahl, Søren; Schaarup-Jensen, Kjeld; Jensen, Jacob Birk

    2007-01-01

    This paper presents a new and alternative method (in the context of urban drainage) for probabilistic hydrodynamical analysis of drainage systems in general and especially prediction of combined sewer overflow. Using a probabilistic shell it is possible to implement both input and parameter...... uncertainties on an application of the commercial urban drainage model MOUSE combined with the probabilistic First Order Reliability Method (FORM). Applying statistical characteristics on several years of rainfall, it is possible to derive a parameterization of the rainfall input and the failure probability...

  10. Probabilistic Modelling of Combined Sewer Overflow Using the First Order Reliability Method

    DEFF Research Database (Denmark)

    Thorndahl, Søren; Schaarup-Jensen, Kjeld; Jensen, Jacob Birk

    2008-01-01

    This paper presents a new and alternative method (in the context of urban drainage) for probabilistic hydrodynamical analysis of drainage systems in general and especially prediction of combined sewer overflow. Using a probabilistic shell it is possible to implement both input and parameter...... uncertainties on an application of the commercial urban drainage model MOUSE combined with the probabilistic First Order Reliability Method (FORM). Applying statistical characteristics on several years of rainfall, it is possible to derive a parameterization of the rainfall input and the failure probability...

  11. Post-rehabilitation evaluation of the sanitary sewer system at Lawrence Livermore National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Royal, D.

    1995-11-01

    We are updating a CH2M Hill study which found that the sanitary sewer system is sufficient to transport peak dry weather flow. However, under peak wet weather conditions, the system has insufficient capacity to transport the projected flows for existing and future development. This is due to the amount of infiltration/inflow (I/I) that enters the sewer system when it rains. Our goal is to examine the existing system to determine its adequacy to accommodate present and future peak flows, and also to further update and improve the CH2M Hill study. A set of alternatives was also developed to address deficiencies of the existing system.

  12. Constructed Wetlands for Treatment of Combined Sewer Overflow in the US: A Review of Design Challenges and Application Status

    OpenAIRE

    Wendong Tao; James S. Bays; Daniel Meyer; Smardon, Richard C.; Zeno F. Levy

    2014-01-01

    As combined sewer systems and centralized wastewater treatment facilities age, many communities in the world are challenged by management of combined sewer overflow (CSO). Constructed wetlands are considered to be one of the green infrastructure solutions to CSOs in the US. Despite the wide application of constructed wetlands to different types of wastewaters, the stochastic and intermittent nature of CSO presents challenges for design and performance assessment of constructed wetlands. This ...

  13. Removal of nutrients from combined sewer overflows and lake water in a vertical-flow constructed wetland system.

    Science.gov (United States)

    Gervin, L; Brix, H

    2001-01-01

    Lake Utterslev is situated in a densely built-up area of Copenhagen, and is heavily eutrophicated from combined sewer overflows. At the same time the lake suffers from lack of water. Therefore, a 5,000 m2 vertical flow wetland system was constructed in 1998 to reduce the phosphorus discharge from combined sewer overflows without reducing the water supply to the lake. During dry periods the constructed wetland is used to remove phosphorus from the lake water. The system is designed as a 90 m diameter circular bed with a bed depth of c. 2 m. The system is isolated from the surroundings by a polyethylene membrane. The bed medium consists of a mixture of gravel and crushed marble, which has a high binding capacity for phosphorus. The bed is located within the natural littoral zone of the lake and is planted with common reed (Phragmites australis). The constructed wetland is intermittently loaded with combined sewer overflow water or lake water and, after percolation through the bed medium, the water is collected in a network of drainage pipes at the bottom of the bed and pumped to the lake. The fully automated loading cycle results in alternating wet and dry periods. During the initial two years of operation, the phosphorus removal for combined sewer overflows has been consistently high (94-99% of inflow concentrations). When loaded with lake water, the phosphorus removal has been high during summer (71-97%) and lower during winter (53-75%) partly because of lower inlet concentrations. Effluent phosphorus concentrations are consistently low (0.03-0.04 mg/L). Ammonium nitrogen is nitrified in the constructed wetland, and total suspended solids and COD are generally reduced to concentrations below 5 mg/L and 25 mg/L, respectively. The study documents that a subsurface flow constructed wetland system can be designed and operated to effectively remove phosphorus and other pollutants from combined sewer overflows and eutrophicated lake water.

  14. Combined sewer overflows: an environmental source of hormones and wastewater micropollutants

    Science.gov (United States)

    Phillips, P.J.; Chalmers, A.T.; Gray, J.L.; Kolpin, D.W.; Foreman, W.T.; Wall, G.R.

    2012-01-01

    Data were collected at a wastewater treatment plant (WWTP) in Burlington, Vermont, USA, (serving 30,000 people) to assess the relative contribution of CSO (combined sewer overflow) bypass flows and treated wastewater effluent to the load of steroid hormones and other wastewater micropollutants (WMPs) from a WWTP to a lake. Flow-weighted composite samples were collected over a 13 month period at this WWTP from CSO bypass flows or plant influent flows (n = 28) and treated effluent discharges (n = 22). Although CSO discharges represent 10% of the total annual water discharge (CSO plus treated plant effluent discharges) from the WWTP, CSO discharges contribute 40–90% of the annual load for hormones and WMPs with high (>90%) wastewater treatment removal efficiency. By contrast, compounds with low removal efficiencies (hormones and many WMPs in samples from treated discharges can increase with increasing flow due to decreasing removal efficiency.

  15. Toxicity of combined sewer overflows on river phytoplankton: the role of heavy metals.

    Science.gov (United States)

    Seidl, M; Huang, V; Mouchel, J M

    1998-01-01

    The toxic effect of a combined sewer overflow (CSO) on the phytoplankton community of the river Seine has been studied by means of short-term primary production measurements. As the discharged solids usually do not remain in the water column, only filtered or centrifugated fractions were tested. The collected phytoplankton were grown in the laboratory for 2 days, after addition of N, P and EDTA. Stock cultures in exponential growth were directly tested with heavy metals, but resuspended algal cells were used for effluent testing. The results show an increase of EC50 value for the single metal species in the order Cu

  16. Assessing combined sewer overflows with long lead time for better surface water management.

    Science.gov (United States)

    Abdellatif, Mawada; Atherton, William; Alkhaddar, Rafid

    2014-01-01

    During high-intensity rainfall events, the capacity of combined sewer overflows (CSOs) can exceed resulting in discharge of untreated stormwater and wastewater directly into receiving rivers. These discharges can result in high concentrations of microbial pathogens, biochemical oxygen demand, suspended solids, and other pollutants in the receiving waters. The frequency and severity of the CSO discharge are strongly influenced by climatic factors governing the occurrence of urban stormwater runoff, particularly the amount and intensity of the rainfall. This study attempts to assess the impact of climate change (change in rainfall amount and frequency) on CSO under the high (A1FI) and low (B1) Special Report on Emissions Scenarios of the greenhouse concentration derived from three global circulation models in the north west of England at the end of the twenty-first century.

  17. Modelling the impacts of Combined Sewer Overflows on the river Seine water quality.

    Science.gov (United States)

    Even, Stéphanie; Mouchel, Jean-Marie; Servais, Pierre; Flipo, Nicolas; Poulin, Michel; Blanc, Stéphanie; Chabanel, Matthieu; Paffoni, Catherine

    2007-04-01

    To achieve the objectives of the European Water Framework Directive (EWFD), the Seine basin Water Authority has constructed a number of prospective scenarios forecasting the impact of planned investments in water quality. Paris and its suburbs were given special attention because of their impact on the river Seine. Paris sewer system and overflow control is of major concern in future management plans. The composition and fate of the urban effluents have been characterized through numerous in situ samplings, laboratory experiments and modelling studies. The PROSE model was especially designed to simulate the impact on the river of both permanent dry-weather effluents and of highly transient Combined Sewer Overflow (CSO). It was also used to represent the impact of Paris at large spatial and temporal scales. In addition to immediate effects on oxygen levels, heavy particulate organic matter loads that settle downstream of the outlets contribute to permanent oxygen consumption. Until the late 90s, the 50 km long reach of the Seine inside Paris was permanently affected by high oxygen consumption accounting for 112% of the flux upstream of the city. 20% of this demand resulted from CSO. However, the oxygenation of the system is strong due to high phytoplankton activity. As expected, the model results predict a reduction of both permanent dry-weather effluents and CSOs in the future that will greatly improve the oxygen levels (concentrations higher than 7.3 mgO(2) L(-1), 90% of the time instead of 4.0 mgO(2) L(-1) in the late 90s). The main conclusion is that, given the spatial and temporal extent of the impact of many CSOs, water quality models should take into account the CSOs in order to be reliable.

  18. Coupled 1D-2D hydrodynamic inundation model for sewer overflow: Influence of modeling parameters

    Directory of Open Access Journals (Sweden)

    Adeniyi Ganiyu Adeogun

    2015-10-01

    Full Text Available This paper presents outcome of our investigation on the influence of modeling parameters on 1D-2D hydrodynamic inundation model for sewer overflow, developed through coupling of an existing 1D sewer network model (SWMM and 2D inundation model (BREZO. The 1D-2D hydrodynamic model was developed for the purpose of examining flood incidence due to surcharged water on overland surface. The investigation was carried out by performing sensitivity analysis on the developed model. For the sensitivity analysis, modeling parameters, such as mesh resolution Digital Elevation Model (DEM resolution and roughness were considered. The outcome of the study shows the model is sensitive to changes in these parameters. The performance of the model is significantly influenced, by the Manning's friction value, the DEM resolution and the area of the triangular mesh. Also, changes in the aforementioned modeling parameters influence the Flood characteristics, such as the inundation extent, the flow depth and the velocity across the model domain.

  19. Combined sewer overflow control with LID based on SWMM: an example in Shanghai, China.

    Science.gov (United States)

    Liao, Z L; Zhang, G Q; Wu, Z H; He, Y; Chen, H

    2015-01-01

    Although low impact development (LID) has been commonly applied across the developed countries for mitigating the negative impacts of combined sewer overflows (CSOs) on urban hydrological environment, it has not been widely used in developing countries yet. In this paper, a typical combined sewer system in an urbanized area of Shanghai, China was used to demonstrate how to design and choose CSO control solutions with LID using stormwater management model. We constructed and simulated three types of CSO control scenarios. Our findings support the notion that LID measures possess favorable capability on CSO reduction. Nevertheless, the green scenarios which are completely comprised by LID measures fail to achieve the maximal effectiveness on CSO reduction, while the gray-green scenarios (LID measure combined with gray measures) achieve it. The unit cost-effectiveness of each type of scenario sorts as: green scenario > gray-green scenario > gray scenario. Actually, as the storage tank is built in the case catchment, a complete application of green scenario is inaccessible here. Through comprehensive evaluation and comparison, the gray-green scenario F which used the combination of storage tank, bio-retention and rain barrels is considered as the most feasible one in this case.

  20. Contribution of combined sewer overflows to trace contaminant loads in urban streams.

    Science.gov (United States)

    Weyrauch, Philip; Matzinger, Andreas; Pawlowsky-Reusing, Erika; Plume, Stephan; von Seggern, Dörthe; Heinzmann, Bernd; Schroeder, Kai; Rouault, Pascale

    2010-08-01

    The present study examines the contribution of combined sewer overflows (CSO) to loads and concentrations of trace contaminants in receiving surface water. A simple method to assess the ratio of CSO to wastewater treatment plant (WWTP) effluents was applied to the urban River Spree in Berlin, Germany. The assessment indicated that annual loads are dominated by CSO for substances with removal in WWTP above approximately 95%. Moreover, it showed that substances with high removal in WWTP can lead to concentration peaks in the river during CSO events. The calculated results could be verified based on eight years of monitoring data from the River Spree, collected between 2000 and 2007. Substances that are well removed in WWTP such as NTA (nitrilotriacetic acid) were found to occur in significantly increased concentration during CSO, while the concentration of substances that are poorly removable in WWTP such as EDTA (ethylenediaminetetraacetic acid) decreased in CSO-influenced samples due to dilution effects. The overall results indicate the potential importance of the CSO pathway of well-removable sewage-based trace contaminants to rivers. In particular, high concentrations during CSO events may be relevant for aquatic organisms. Given the results, it is suggested to include well-removable, sewage-based trace contaminants, a substance group often neglected in the past, in future studies on urban rivers in case of combined sewer systems. The presented methodology is suggested for a first assessment, since it is based solely on urban drainage data, which is available in most cities.

  1. Predicting combined sewer overflows chamber depth using artificial neural networks with rainfall radar data.

    Science.gov (United States)

    Mounce, S R; Shepherd, W; Sailor, G; Shucksmith, J; Saul, A J

    2014-01-01

    Combined sewer overflows (CSOs) represent a common feature in combined urban drainage systems and are used to discharge excess water to the environment during heavy storms. To better understand the performance of CSOs, the UK water industry has installed a large number of monitoring systems that provide data for these assets. This paper presents research into the prediction of the hydraulic performance of CSOs using artificial neural networks (ANN) as an alternative to hydraulic models. Previous work has explored using an ANN model for the prediction of chamber depth using time series for depth and rain gauge data. Rainfall intensity data that can be provided by rainfall radar devices can be used to improve on this approach. Results are presented using real data from a CSO for a catchment in the North of England, UK. An ANN model trained with the pseudo-inverse rule was shown to be capable of predicting CSO depth with less than 5% error for predictions more than 1 hour ahead for unseen data. Such predictive approaches are important to the future management of combined sewer systems.

  2. Toxicity and pollutant impact analysis in an urban river due to combined sewer overflows loads.

    Science.gov (United States)

    Casadio, A; Maglionico, M; Bolognesi, A; Artina, S

    2010-01-01

    The Navile Channel (Bologna, Italy) is an ancient artificial water course derived from the Reno river. It is the main receiving water body for the urban catchment of Bologna sewer systems and also for the Waste Water Treatment Plant (WWTP) main outlet. The aim of this work is to evaluate the Combined Sewer Overflows (CSOs) impact on Navile Channel's water quality. In order to collect Navile flow and water quality data in both dry and wet weather conditions, two measuring and sampling stations were installed, right upstream and downstream the WWTP outflow. The study shows that even in case of low intensity rain events, CSOs have a significant effect on both water quantity and quality, spilling a considerable amount of pollutants into the Navile Channel and presenting also acute toxicity effects. The collected data shown a good correlations between the concentrations of TSS and of chemical compounds analyzed, suggesting that the most part of such substances is attached to suspended solids. Resulting toxicity values are fairly high in both measuring points and seem to confirm synergistic interactions between heavy metals.

  3. Climate change impacts on the duration and frequency of combined sewer overflows

    Science.gov (United States)

    Fortier, C.; Mailhot, A.

    2012-12-01

    Combined sewer overflows (CSO) occur when large rainwater inflow from heavy precipitation exceeds the capacity of urban combined sewage systems. Many American and European cities with old sewage systems see their water quality significantly deteriorate during such events. In the long term, changes in the rainfall regime due to climate change may lead to more severe and more frequent CSO episodes and thus compel cities to review their global water management. The overall objective of this study is to investigate how climate change will impact CSO frequency and duration. Data from rain gauges located nearby 30 overflow outfalls, in southern Quebec, Canada, were used to identify rain events leading to overflows, using CSO monitored data from May to October during the period 2007-2009. For each site, occurrence and duration of CSO events were recorded and linked to a rainfall event. Many rain events features can be used to predict CSO events, such as total depth, duration, average intensity and peak intensity. Results based on Pearson product-moment correlation coefficients and multiple regression analysis show that CSO occurrence is best predicted by total rainfall. A methodology is proposed to calculate the CSO probability of occurrence and duration for each site of interest using rainfall series as input data. Monte Carlo method is then used to estimate CSO frequency. To evaluate the climate change impact on CSO, these relationships are used with simulated data from the Canadian Regional Climate Model to compare the distribution of annual number of CSO events over the 1960-1990 period and the 2070-2100 period.

  4. Impact of sewage treatment plants and combined sewer overflow basins on the microbiological quality of surface water.

    Science.gov (United States)

    Rechenburg, A; Koch, Ch; Classen, Th; Kistemann, Th

    2006-01-01

    In a small river catchment, microbiological quality of different sewage treatment plants under regular conditions and in case of heavy rainfall, when combined sewage overflow basins (CSOs) are activated, was examined regarding microbial indicators and pathogens. In the watercourse, no self-cleaning effects could be observed. Small compact treatment plants discharge treated wastewater with a poor microbiological quality compared to river water quality and the quality of treated wastewater of larger plants. During storm water events, concentrations of microorganisms downstream of sewer overflows were approximately two logs higher than during dry weather conditions. Concentrations of parasites decreased slowly during the overflow, in parallel to filterable matter and particle-bound substances. The annual load of microorganisms originating from CSOs significantly exceeds the load from treated effluent of the sewage plants. Thus, an improved hygienic quality of the water course could be achieved by preventing overflows and by enhancing sewage treatment plants.

  5. Remaining Sites Verification Package for the 1607-F3 Sanitary Sewer System, Waste Site Reclassification Form 2006-047

    Energy Technology Data Exchange (ETDEWEB)

    L. M. Dittmer

    2007-04-26

    The 1607-F3 waste site is the former location of the sanitary sewer system that supported the 182-F Pump Station, the 183-F Water Treatment Plant, and the 151-F Substation. The sanitary sewer system included a septic tank, drain field, and associated pipeline, all in use between 1944 and 1965. In accordance with this evaluation, the verification sampling results support a reclassification of this site to Interim Closed Out. The results of verification sampling demonstrated that residual contaminant concentrations do not preclude any future uses and allow for unrestricted use of shallow zone soils. The results also showed that residual contaminant concentrations are protective of groundwater and the Columbia River.

  6. Organic micropollutants discharged by combined sewer overflows - Characterisation of pollutant sources and stormwater-related processes.

    Science.gov (United States)

    Launay, Marie A; Dittmer, Ulrich; Steinmetz, Heidrun

    2016-11-01

    To characterise emissions from combined sewer overflows (CSOs) regarding organic micropollutants, a monitoring study was undertaken in an urban catchment in southwest Stuttgart, Germany. The occurrence of 69 organic micropollutants was assessed at one CSO outfall during seven rain events as well as in the sewage network at the influent of the wastewater treatment plant (WWTP) and in the receiving water. Several pollutant groups like pharmaceuticals and personal care products (PPCPs), urban biocides and pesticides, industrial chemicals, organophosphorus flame retardants, plasticisers and polycyclic aromatic hydrocarbons (PAHs) were chosen for analysis. Out of the 69 monitored substances, 60 were detected in CSO discharges. The results of this study show that CSOs represent an important pathway for a wide range of organic micropollutants from wastewater systems to urban receiving waters. For most compounds detected in CSO samples, event mean concentrations varied between the different events in about one order of magnitude range. When comparing CSO concentrations with median wastewater concentrations during dry weather, two main patterns could be observed depending on the source of the pollutant: (i) wastewater is diluted by stormwater; (ii) stormwater is the most important source of a pollutant. Both wastewater and stormwater only play an important role in pollutant concentration for a few compounds. The proportion of stormwater calculated with the conductivity is a suitable indicator for the evaluation of emitted loads of dissolved wastewater pollutants, but not for all compounds. In fact, this study demonstrates that remobilisation of in-sewer deposits contributed from 10% to 65% to emissions of carbamazepine in CSO events. The contribution of stormwater to CSO emitted loads was higher than 90% for all herbicides as well as for PAHs. Regarding the priority substance di(2-ethylhexyl)phthalate (DEHP), this contribution varied between 39% and 85%. The PAH

  7. Evaluation of Ecotoxicological Risks Related to the Discharge of Combined Sewer Overflows (CSOs) in a Periurban River

    OpenAIRE

    Evens Emmanuel; Yves Perrodin; Ruth Angerville; Christine Bazin

    2013-01-01

    Discharges of Combined Sewer Overflows (CSOs) into periurban rivers present risks for the concerned aquatic ecosystems. In this work, a specific ecotoxicological risk assessment methodology has been developed as management tool to municipalities equipped with CSOs. This methodology comprises a detailed description of the spatio-temporal system involved, the choice of ecological targets to be preserved, and carrying out bioassays adapted to each compartment of the river receiving CSOs. Once fo...

  8. Temporal variability of combined sewer overflow contaminants: evaluation of wastewater micropollutants as tracers of fecal contamination.

    Science.gov (United States)

    Madoux-Humery, Anne-Sophie; Dorner, Sarah; Sauvé, Sébastien; Aboulfadl, Khadija; Galarneau, Martine; Servais, Pierre; Prévost, Michèle

    2013-09-01

    A monitoring program was initiated for two sewage outfalls (OA and OB) with different land uses (mainly residential versus institutional) over the course of a year. Eleven CSO events resulting from fall and summer precipitations and a mixture of snowmelt and precipitation in late winter and early spring were monitored. Median concentrations measured in CSOs were 1.5 × 10(6)Escherichia coli/100 mL, 136.0 mg/L of Total Suspended Solids (TSS), 4599.0 ng/L of caffeine (CAF), 158.9 ng/L of carbamazepine (CBZ), in outfall OA and 5.1 × 10(4)E. coli/100 mL, 167.0 mg TSS/L, 300.8 ng CAF/L, 4.1 ng CBZ/L, in outfall OB. Concentration dynamics in CSOs were mostly related to the dilution by stormwater and the time of day of the onset of overflows. Snowmelt was identified as a critical period with regards to the protection of drinking water sources given the high contaminant concentrations and long duration of events in addition to a lack of restrictions on overflows during this period. Correlations among measured parameters reflected the origins and transport pathways of the contaminants, with E. coli being correlated with CBZ. TSS were not correlated with E. coli because E. coli was found to be mostly associated with raw sewage whereas TSS were additionally from the resuspension of in-sewer deposits and surface runoff. In receiving waters, E. coli remained the best indicator of fecal contamination in strongly diluted water samples as compared to WWMPs because WWMPs can be diluted to below their detection limits.

  9. Evaluation of exposure pathways to man from disposal of radioactive materials into sanitary sewer systems

    Energy Technology Data Exchange (ETDEWEB)

    Kennedy, W.E. Jr.; Parkhurst, M.A.; Aaberg, R.L.; Rhoads, K.C.; Hill, R.L.; Martin, J.B. [Pacific Northwest Lab., Richland, WA (United States)

    1992-05-01

    In accordance with 10 CFR 20, the US Nuclear Regulatory Commission (NRC) regulates licensees` discharges of small quantities of radioactive materials into sanitary sewer systems. This generic study was initiated to examine the potential radiological hazard to the public resulting from exposure to radionuclides in sewage sludge during its treatment and disposal. Eleven scenarios were developed to characterize potential exposures to radioactive materials during sewer system operations and sewage sludge treatment and disposal activities and during the extended time frame following sewage sludge disposal. Two sets of deterministic dose calculations were performed; one to evaluate potential doses based on the radionuclides and quantities associated with documented case histories of sewer system contamination and a second, somewhat more conservative set, based on theoretical discharges at the maximum allowable levels for a more comprehensive list of 63 radionuclides. The results of the stochastic uncertainty and sensitivity analysis were also used to develop a collective dose estimate. The collective doses for the various radionuclides and scenarios range from 0.4 person-rem for {sup 137}Cs in Scenario No. 5 (sludge incinerator effluent) to 420 person-rem for {sup 137}Cs in Scenario No. 3 (sewage treatment plant liquid effluent). None of the 22 scenario/radionuclide combinations considered have collective doses greater than 1000 person-rem/yr. However, the total collective dose from these 22 combinations was found to be about 2100 person-rem.

  10. Wastewater effluent, combined sewer overflows, and other sources of organic compounds to Lake Champlain

    Science.gov (United States)

    Phillips, P.; Chalmers, A.

    2009-01-01

    Some sources of organic wastewater compounds (OWCs) to streams, lakes, and estuaries, including wastewater-treatment-plant effluent, have been well documented, but other sources, particularly wet-weather discharges from combined-sewer-overflow (CSO) and urban runoff, may also be major sources of OWCs. Samples of wastewater-treatment-plant (WWTP) effluent, CSO effluent, urban streams, large rivers, a reference (undeveloped) stream, and Lake Champlain were collected from March to August 2006. The highest concentrations of many OWCs associated with wastewater were in WWTP-effluent samples, but high concentrations of some OWCs in samples of CSO effluent and storm runoff from urban streams subject to leaky sewer pipes or CSOs were also detected. Total concentrations and numbers of compounds detected differed substantially among sampling sites. The highest total OWC concentrations (10-100 ??g/l) were in samples of WWTP and CSO effluent. Total OWC concentrations in samples from urban streams ranged from 0.1 to 10 ??g/l, and urban stream-stormflow samples had higher concentrations than baseflow samples because of contributions of OWCs from CSOs and leaking sewer pipes. The relations between OWC concentrations in WWTP-effluent and those in CSO effluent and urban streams varied with the degree to which the compound is removed through normal wastewater treatment. Concentrations of compounds that are highly removed during normal wastewater treatment [including caffeine, Tris(2-butoxyethyl)phosphate, and cholesterol] were generally similar to or higher in CSO effluent than in WWTP effluent (and ranged from around 1 to over 10 ??g/l) because CSO effluent is untreated, and were higher in urban-stream stormflow samples than in baseflow samples as a result of CSO discharge and leakage from near-surface sources during storms. Concentrations of compounds that are poorly removed during treatment, by contrast, are higher in WWTP effluent than in CSO, due to dilution. Results indicate

  11. Chemical disinfection of combined sewer overflow waters using performic acid or peracetic acids.

    Science.gov (United States)

    Chhetri, Ravi Kumar; Thornberg, Dines; Berner, Jesper; Gramstad, Robin; Öjstedt, Ulrik; Sharma, Anitha Kumari; Andersen, Henrik Rasmus

    2014-08-15

    We investigated the possibility of applying performic acid (PFA) and peracetic acid (PAA) for disinfection of combined sewer overflow (CSO) in existing CSO management infrastructures. The disinfection power of PFA and PAA towards Escherichia coli (E. coli) and Enterococcus was studied in batch-scale and pre-field experiments. In the batch-scale experiment, 2.5 mg L(-1) PAA removed approximately 4 log unit of E. coli and Enterococcus from CSO with a 360 min contact time. The removal of E. coli and Enterococcus from CSO was always around or above 3 log units using 2-4 mg L(-1) PFA; with a 20 min contact time in both batch-scale and pre-field experiments. There was no toxicological effect measured by Vibrio fischeri when CSO was disinfected with PFA; a slight toxic effect was observed on CSO disinfected with PAA. When the design for PFA based disinfection was applied to CSO collected from an authentic event, the disinfection efficiencies were confirmed and degradation rates were slightly higher than predicted in simulated CSO.

  12. The evaluation of rainfall influence on combined sewer overflows characteristics: the Berlin case study.

    Science.gov (United States)

    Sandoval, S; Torres, A; Pawlowsky-Reusing, E; Riechel, M; Caradot, N

    2013-01-01

    The present study aims to explore the relationship between rainfall variables and water quality/quantity characteristics of combined sewer overflows (CSOs), by the use of multivariate statistical methods and online measurements at a principal CSO outlet in Berlin (Germany). Canonical correlation results showed that the maximum and average rainfall intensities are the most influential variables to describe CSO water quantity and pollutant loads whereas the duration of the rainfall event and the rain depth seem to be the most influential variables to describe CSO pollutant concentrations. The analysis of partial least squares (PLS) regression models confirms the findings of the canonical correlation and highlights three main influences of rainfall on CSO characteristics: (i) CSO water quantity characteristics are mainly influenced by the maximal rainfall intensities, (ii) CSO pollutant concentrations were found to be mostly associated with duration of the rainfall and (iii) pollutant loads seemed to be principally influenced by dry weather duration before the rainfall event. The prediction quality of PLS models is rather low (R² < 0.6) but results can be useful to explore qualitatively the influence of rainfall on CSO characteristics.

  13. Micropollutants in stormwater runoff and combined sewer overflow in the Copenhagen area, Denmark.

    Science.gov (United States)

    Birch, H; Mikkelsen, P S; Jensen, J K; Lützhøft, H-C Holten

    2011-01-01

    Stormwater runoff contains a broad range of micropollutants. In Europe a number of these substances are regulated through the Water Framework Directive, which establishes Environmental Quality Standards (EQSs) for surface waters. Knowledge about discharge of these substances through stormwater runoff and combined sewer overflows (CSOs) is essential to ensure compliance with the EQSs. Results from a screening campaign including more than 50 substances at four stormwater discharge locations and one CSO in Copenhagen are reported here. Heavy metal concentrations were detected at levels similar to earlier findings, e.g., with copper found at concentrations up to 13 times greater than the Danish standard for surface waters. The concentration of polyaromatic hydrocarbons (PAHs) exceeded the EQSs by factors up to 500 times for stormwater and 2,000 times for the CSO. Glyphosate was found in all samples whilst diuron, isoproturon, terbutylazine and MCPA were found only in some of the samples. Diethylhexylphthalate (DEHP) was also found at all five locations in concentrations exceeding the EQS. The results give a valuable background for designing further monitoring programmes focusing on the chemical status of surface waters in urban areas.

  14. Modelling of E. coli distribution in coastal areas subjected to combined sewer overflows.

    Science.gov (United States)

    De Marchis, Mauro; Freni, Gabriele; Napoli, Enrico

    2013-01-01

    Rivers, lakes and the sea were the natural receivers of raw urban waste and storm waters for a long time but the low sustainability of such practice, the increase of population and a renewed environmental sensibility increased researcher interest in the analysis and mitigation of the impact of urban waters on receiving water bodies (RWB). In Europe, the integrated modelling of drainage systems and RWB has been promoted as a promising approach for implementing the Water Framework Directive. A particular interest is given to the fate of pathogens and especially of Escherichia coli, in all the cases in which an interaction between population and the RWB is foreseen. The present paper aims to propose an integrated water quality model involving the analysis of several sewer systems (SS) discharging their polluting overflows on the coast in a sensitive marine environment. From a modelling point of view, the proposed application integrated one-dimensional drainage system models with a complex three-dimensional model analysing the propagation in space and time of E. coli in the coastal marine area. The integrated approach was tested in a real case study (the Acicastello bay in Italy) where data were available both for SS model and for RWB propagation model calibration. The analysis shows a good agreement between the model and monitored data. The integrated model was demonstrated to be a valuable tool for investigating the pollutant propagation and to highlight the most impacted areas.

  15. Combined Sewer Overflows as a Source of Hormones to Surface Water

    Science.gov (United States)

    Phillips, P.; Chalmers, A.; Gray, J. L.; Foreman, W.; Kolpin, D. W.; Wall, G.; Esposito, K.

    2009-12-01

    Some sources of hormones to surface water, such as wastewater-treatment-plant (WWTP) effluent, have been well documented, but other sources, particularly wet-weather discharges from combined-sewer-overflows (CSOs), are not well characterized. Flow-weighted composite samples of secondarily treated WWTP effluent and untreated sewage discharges from WWTP inflows and CSO discharges were collected during 12 storms and 6 non-storm conditions from November 2007-December 2008 at the main Burlington Vermont WWTP. Concentrations of many androgens and estrogens were highest in samples from untreated sewage, and lower in samples from treated sewage. For example, concentrations of estriol in CSO samples ranged from 5 to over 100 ng/L (nanograms per liter), but were generally less than 1 ng/L in treated sewage. Many androgens were detected in CSO discharge samples in concentrations ranging from 1 to over 1000 ng/L, but were not detected above 1 ng/L in treated samples. For many of the hormones, including androgens and estriol, CSO discharges comprised over half of the total load discharged by the WWTP, even though annual CSO discharge is less than 10% of the treated plant discharge. These results indicate that untreated discharges during CSO events can be a major source of some hormones and other wastewater compounds to the environment.

  16. Model evaluation of faecal contamination in coastal areas affected by urban rivers receiving combined sewer overflows.

    Science.gov (United States)

    Shibata, T; Kojima, K; Lee, S A; Furumai, H

    2014-01-01

    Odaiba seaside park is one of the most popular waterfronts in Tokyo Bay, but is easily affected by wet weather pollutant loads through combined sewer overflows (CSOs). The monitoring data of Escherichia coli clearly showed high faecal contamination after a rainfall event on 9-11 November 2007. We estimated the amounts of discharge volume and E. coli pollutant loads of urban rivers receiving CSO from rainfall chambers as well as pumping stations and primary effluent discharge. The result suggested that Sumida River and Meguro River were more influential to the Odaiba coastal area than other sources including the nearest wastewater treatment plant. Subsequently, we simulated the dynamic behaviour of E. coli by a three-dimensional (3D) hydro-dynamic and water quality model. The model simulation reproduced that E. coli concentration after the rainfall event increased rapidly at first and later gradually decreased. The simulations with and without inflow pollutant loads from urban rivers suggested that the E. coli concentration can be influenced by the Meguro River just after the rainfall event and Sumida River about 1 week later. From the spatial and temporal distribution of surface E. coli concentration, after at least 6 days from the rainfall event, high faecal contamination spread to the whole of the coastal area.

  17. London Tideway Tunnels: tackling London's Victorian legacy of combined sewer overflows.

    Science.gov (United States)

    Thomas, G B; Crawford, D

    2011-01-01

    It takes a few millimetres of rainfall to cause the 34 most polluting combined sewer overflows (CSOs) to discharge into the River Thames. Currently, in a typical year, spillages to the tidal reaches of the River Thames occur about 60 times, with an estimated spill volume of 39 million cubic metres. Both the UK Government and the European Union have determined that the CSO discharges have an adverse environmental impact on fish species, introduce unacceptable aesthetics and elevate the health risks for recreational users of the Thames, with a frequency of discharge which is in breach of the Urban Wastewater Treatment Directive. Studies have established that the environmental objectives can be fully met on the most cost-effective basis by completing both quality improvements to treatment works and by the provision of a storage and transfer tunnel to intercept unsatisfactory CSOs. Extensive modelling has been undertaken to develop an optimised solution. In parallel with the design development a rigorous and comprehensive site selection methodology has been established to select sites and consult stakeholders and the public on the preferred sites and scheme, with the first stage of public consultation planned for later in 2010. The London Tideway Tunnels are an essential part of the delivery of improvements to the water quality of the tidal River Thames, and this ambitious, historic scheme represents a vital strategic investment in London's infrastructure.

  18. Widespread, routine occurrence of pharmaceuticals in sewage effluent, combined sewer overflows and receiving waters.

    Science.gov (United States)

    Kay, Paul; Hughes, Stephen R; Ault, James R; Ashcroft, Alison E; Brown, Lee E

    2017-01-01

    Research addressing the occurrence, fate and effects of pharmaceuticals in the aquatic environment has expanded rapidly over the past two decades, primarily due to the development of improved chemical analysis methods. Significant research gaps still remain, however, including a lack of longer term, repeated monitoring of rivers, determination of temporal and spatial changes in pharmaceutical concentrations, and inputs from sources other than wastewater treatment plants (WWTPs), such as combined sewer overflows (CSOs). In addressing these gaps it was found that the five pharmaceuticals studied were routinely (51-94% of the time) present in effluents and receiving waters at concentrations ranging from single ng to μg L(-1). Mean concentrations were in the tens to hundreds ng L(-1) range and CSOs appear to be a significant source of pharmaceuticals to water courses in addition to WWTPs. Receiving water concentrations varied throughout the day although there were no pronounced peaks at particular times. Similarly, concentrations varied throughout the year although no consistent patterns were observed. No dissipation of the study compounds was found over a 5 km length of river despite no other known inputs to the river. In conclusion, pharmaceuticals are routinely present in semi-rural and urban rivers and require management alongside more traditional pollutants.

  19. Modelling sewer sediment deposition, erosion, and transport processes to predict acute influent and reduce combined sewer overflows and CO(2) emissions.

    Science.gov (United States)

    Mouri, Goro; Oki, Taikan

    2010-01-01

    Understanding of solids deposition, erosion, and transport processes in sewer systems has improved considerably in the past decade. This has provided guidance for controlling sewer solids and associated acute pollutants to protect the environment and improve the operation of wastewater systems. Although measures to decrease combined sewer overflow (CSO) events have reduced the amount of discharged pollution, overflows continue to occur during rainy weather in combined sewer systems. The solution lies in the amount of water allotted to various processes in an effluent treatment system, in impact evaluation of water quality and prediction technology, and in stressing the importance of developing a control technology. Extremely contaminated inflow has been a serious research subject, especially in connection with the influence of rainy weather on nitrogen and organic matter removal efficiency in wastewater treatment plants (WWTP). An intensive investigation of an extremely polluted inflow load to WWTP during rainy weather was conducted in the city of Matsuyama, the region used for the present research on total suspended solid (TSS) concentration. Since the inflow during rainy weather can be as much as 400 times that in dry weather, almost all sewers are unsettled and overflowing when a rain event is more than moderate. Another concern is the energy consumed by wastewater treatment; this problem has become important from the viewpoint of reducing CO(2) emissions and overall costs. Therefore, while establishing a prediction technology for the inflow water quality characteristics of a sewage disposal plant is an important priority, the development of a management/control method for an effluent treatment system that minimises energy consumption and CO(2) emissions due to water disposal is also a pressing research topic with regards to the quality of treated water. The procedure to improve water quality must make use of not only water quality and biotic criteria, but also

  20. Field validation of a new low-cost method for determining occurrence and duration of combined sewer overflows.

    Science.gov (United States)

    Montserrat, A; Gutierrez, O; Poch, M; Corominas, Ll

    2013-10-01

    Combined sewer overflow (CSO) events produced in combined sewer systems (CSS) during wet weather conditions are a threat for the receiving water bodies. The large number of CSO structures normally present in a CSS makes that the monitoring of the complete CSO network in a simultaneous way would drastically increase the investment costs. In this paper, a new methodology is presented aiming to characterize the occurrence and duration of CSO events by means of low-cost temperature sensors. Hence, a large number of CSO structures can be simultaneously monitored and the system can be characterized as a whole. The method assumes temperature differences between the overflowing mix of wastewater and stormwater and the sewer gas phase, so the temperature shift produced during a rainfall episode is related to a CSO event occurrence. The method has been tested and validated in La Garriga CSS (Spain) where the temperature at 13 CSO weirs was monitored for a period of 1 year (57 rainfall episodes). For the whole set of CSO events, occurrence and duration were successfully determined in 80% of cases. Advantages, limitations and potential applications of the method are discussed at the end of the paper.

  1. Hydraulic Modeling and Evolutionary Optimization for Enhanced Real-Time Decision Support of Combined Sewer Overflows

    Science.gov (United States)

    Zimmer, A. L.; Minsker, B. S.; Schmidt, A. R.; Ostfeld, A.

    2011-12-01

    Real-time mitigation of combined sewer overflows (CSOs) requires evaluation of multiple operational strategies during rapidly changing rainfall events. Simulation models for hydraulically complex systems can effectively provide decision support for short time intervals when coupled with efficient optimization. This work seeks to reduce CSOs for a test case roughly based on the North Branch of the Chicago Tunnel and Reservoir Plan (TARP), which is operated by the Metropolitan Water Reclamation District of Greater Chicago (MWRDGC). The North Branch tunnel flows to a junction with the main TARP system. The Chicago combined sewer system alleviates potential CSOs by directing high interceptor flows through sluice gates and dropshafts to a deep tunnel. Decision variables to control CSOs consist of sluice gate positions that control water flow to the tunnel as well as a treatment plant pumping rate that lowers interceptor water levels. A physics-based numerical model is used to simulate the hydraulic effects of changes in the decision variables. The numerical model is step-wise steady and conserves water mass and momentum at each time step by iterating through a series of look-up tables. The look-up tables are constructed offline to avoid extensive real-time calculations, and describe conduit storage and water elevations as a function of flow. A genetic algorithm (GA) is used to minimize CSOs at each time interval within a moving horizon framework. Decision variables are coded at 15-minute increments and GA solutions are two hours in duration. At each 15-minute interval, the algorithm identifies a good solution for a two-hour rainfall forecast. Three GA modifications help reduce optimization time. The first adjustment reduces the search alphabet by eliminating sluice gate positions that do not influence overflow volume. The second GA retains knowledge of the best decision at the previous interval by shifting the genes in the best previous sequence to initialize search at

  2. Coupling urban event-based and catchment continuous modelling for combined sewer overflow river impact assessment

    Science.gov (United States)

    Andrés-Doménech, I.; Múnera, J. C.; Francés, F.; Marco, J. B.

    2010-10-01

    Since Water Framework Directive (WFD) was passed in year 2000, the conservation of water bodies in the EU must be understood in a completely different way. Regarding to combined sewer overflows (CSOs) from urban drainage networks, the WFD implies that we cannot accept CSOs because of their intrinsic features, but they must be assessed for their impact on the receiving water bodies in agreement with specific environmental aims. Consequently, both, urban system and the receiving water body must be jointly analysed to evaluate the environmental impact generated on the latter. In this context, a coupled scheme is presented in this paper to assess the CSOs impact on a river system in Torrelavega (Spain). First, a urban model is developed to statistically characterise the CSOs frequency, volume and duration. The main feature of this first model is the fact of being event-based: the system is modelled with some built synthetic storms which cover adequately the probability range of the main rainfall descriptors, i.e., rainfall event volume and peak intensity. Thus, CSOs are characterised in terms of their occurrence probability. Secondly, a continuous and distributed basin model is built to assess river response at different points in the river network. This model was calibrated initially on a daily scale and downscaled later to hourly scale. The main objective of this second element of the scheme is to provide the most likely state of the receiving river when a CSO occurs. By combining results of both models, CSO and river flows are homogeneously characterised from a statistical point of view. Finally, results from both models were coupled to estimate the final concentration of some analysed pollutants (biochemical oxygen demand, BOD, and total ammonium, NH4+), within the river just after the spills.

  3. Coupling urban event-based and catchment continuous modelling for combined sewer overflow river impact assessment

    Directory of Open Access Journals (Sweden)

    I. Andrés-Doménech

    2010-10-01

    Full Text Available Since Water Framework Directive (WFD was passed in year 2000, the conservation of water bodies in the EU must be understood in a completely different way. Regarding to combined sewer overflows (CSOs from urban drainage networks, the WFD implies that we cannot accept CSOs because of their intrinsic features, but they must be assessed for their impact on the receiving water bodies in agreement with specific environmental aims. Consequently, both, urban system and the receiving water body must be jointly analysed to evaluate the environmental impact generated on the latter. In this context, a coupled scheme is presented in this paper to assess the CSOs impact on a river system in Torrelavega (Spain. First, a urban model is developed to statistically characterise the CSOs frequency, volume and duration. The main feature of this first model is the fact of being event-based: the system is modelled with some built synthetic storms which cover adequately the probability range of the main rainfall descriptors, i.e., rainfall event volume and peak intensity. Thus, CSOs are characterised in terms of their occurrence probability. Secondly, a continuous and distributed basin model is built to assess river response at different points in the river network. This model was calibrated initially on a daily scale and downscaled later to hourly scale. The main objective of this second element of the scheme is to provide the most likely state of the receiving river when a CSO occurs. By combining results of both models, CSO and river flows are homogeneously characterised from a statistical point of view. Finally, results from both models were coupled to estimate the final concentration of some analysed pollutants (biochemical oxygen demand, BOD, and total ammonium, NH4+, within the river just after the spills.

  4. Coupling urban event-based and catchment continuous modelling for combined sewer overflow river impact assessment

    Directory of Open Access Journals (Sweden)

    I. Andrés-Doménech

    2010-05-01

    Full Text Available Since the Water Framework Directive (WFD was passed in year 2000, the protection of water bodies in the EU must be understood in a completely different way. Regarding to combined sewer overflows (CSOs from urban drainage networks, the WFD implies that CSOs cannot be accepted because of their intrinsic features, but must be assessed for their impact on the receiving water bodies in agreement with specific environmental aims. Consequently, both, the urban system and the receiving one must be jointly analysed to evaluate their impact. In this context, a coupled scheme is presented in this paper to assess the CSOs impact in a river system in Torrelavega (Spain. First, an urban model is developed to characterise statistically the CSOs frequency, volume and duration. The main feature of this first model is the fact of being event-based: the system is modelled with some built synthetic storms which cover adequately the probability range of the main rainfall descriptors, i.e., rainfall event volume and peak intensity. Thus, CSOs are characterised in terms of their occurrence probability. Secondly, a continuous and distributed basin model is built to assess the river response at different points in the river network. This model was calibrated initially on a daily scale and downscaled later to the hourly scale. The main objective of this second element of the scheme is to provide the most likely state of the receiving river when a CSO occurs. By combining results of both models, CSO and river flows are homogeneously characterised from a statistical point of view. Finally, results from both models were coupled to estimate the final concentration of some analysed pollutants (the biochemical oxygen demand, BOD, and the total ammonium, NH4+, in the river just after the spills.

  5. Quantitative detection of human adenoviruses in wastewater and combined sewer overflows influencing a Michigan river.

    Science.gov (United States)

    Fong, Theng-Theng; Phanikumar, Mantha S; Xagoraraki, Irene; Rose, Joan B

    2010-02-01

    Enteric viruses are important pathogens found in contaminated surface waters and have previously been detected in waters of the Great Lakes. Human adenoviruses were monitored because of their high prevalence and persistence in aquatic environments. In this study, we quantified adenoviruses in wastewater, surface water, and combined sewer overflows (CSOs) by real-time PCR. Between August 2005 and August 2006, adenovirus concentrations in raw sewage, primary-treated effluent, secondary-treated effluent, and chlorinated effluent from a wastewater treatment plant in Michigan were examined. CSO samples (n = 6) were collected from a CSO retention basin in Grand Rapids, MI. Adenoviruses were detected in 100% of wastewater and CSO discharge samples. Average adenovirus DNA concentrations in sewage and CSOs were 1.15 x 10(6) viruses/liter and 5.35 x 10(5) viruses/liter, respectively. Adenovirus removal was <2 log(10) (99%) at the wastewater treatment plant. Adenovirus type 41 (60% of clones), type 12 (29%), type 40 (3%), type 2 (3%), and type 3 (3%) were isolated from raw sewage and primary effluents (n = 28). Six of 20 surface water samples from recreational parks at the lower Grand River showed virus concentrations above the real-time PCR detection limit (average, 7.8 x 10(3) viruses/liter). This research demonstrates that wastewater effluents and wastewater-impacted surface waters in the lower Grand River in Michigan contain high levels of viruses and may not be suitable for full-body recreational activities. High concentrations of adenovirus in these waters may be due to inefficient removal during wastewater treatment and to the high persistence of these viruses in the environment.

  6. Full scale evaluation of combined sewer overflows disinfection using performic acid in a sea-outfall pipe

    DEFF Research Database (Denmark)

    Chhetri, Ravi Kumar; Flagstad, Rasmus; Sonne Munch, Ebbe

    2015-01-01

    Pollution of surface waters with pathogens from combined sewer overflows limits recreational use of surface waters. Large retention basins are a satisfactory solution but they are rarely sufficient for economic or space reasons. Fast disinfection during the overflow is an alternative, but few...... methods are known and each has problems. This work evaluated for the first time the full-scale disinfection using performic acid by the removal of the two currently regulated indicator bacteria for bathing water quality, E. coli and Enterococcus. Experiments were performed at a sewage bypass through a sea......-outfall pipe with a minimum hydraulic retention time of 24 min. The disinfection efficiency in the field was measured by analyzing samples taken before and after the treatment. Samples were also treated with performic acid in the laboratory to measure the disinfection effectiveness and kinetic of degradation...

  7. Influence of changes of the wastewater composition on the applicability of UV-absorption measurements at combined sewer overflows.

    Science.gov (United States)

    Stumwöhrer, K; Matsché, N; Winkler, S

    2003-01-01

    The applicability of UV-absorption measurements at combined sewer overflows was investigated under different storm water conditions. Three specific rainfall events of different intensity, different duration and different intervals between the events were investigated. An individual evaluation of each single event resulted in an acceptable correlation between the UV absorption and the pollution measured as COD. A combined evaluation of the different events exhibited a very poor correlation which could not be used as pollution control parameter. Since the calibration procedure of the spectrometer used was not flexible enough to distinguish between different wastewater matrices from the different storm events the applicability of this type of spectrometer for the control of storm water overflows is questionable.

  8. Evaluating rain gardens as a method to reduce the impact of sewer overflows in sources of drinking water.

    Science.gov (United States)

    Autixier, Laurène; Mailhot, Alain; Bolduc, Samuel; Madoux-Humery, Anne-Sophie; Galarneau, Martine; Prévost, Michèle; Dorner, Sarah

    2014-11-15

    The implications of climate change and changing precipitation patterns need to be investigated to evaluate mitigation measures for source water protection. Potential solutions need first to be evaluated under present climate conditions to determine their utility as climate change adaptation strategies. An urban drainage network receiving both stormwater and wastewater was studied to evaluate potential solutions to reduce the impact of combined sewer overflows (CSOs) in a drinking water source. A detailed hydraulic model was applied to the drainage basin to model the implementation of best management practices at a drainage basin scale. The model was calibrated and validated with field data of CSO flows for seven events from a survey conducted in 2009 and 2010. Rain gardens were evaluated for their reduction of volumes of water entering the drainage network and of CSOs. Scenarios with different levels of implementation were considered and evaluated. Of the total impervious area within the basin directly connected to the sewer system, a maximum of 21% could be alternately directed towards rain gardens. The runoff reductions for the entire catchment ranged from 12.7% to 19.4% depending on the event considered. The maximum discharged volume reduction ranged from 13% to 62% and the maximum peak flow rate reduction ranged from 7% to 56%. Of concern is that in-sewer sediment resuspension is an important process to consider with regard to the efficacy of best management practices aimed at reducing extreme loads and concentrations. Rain gardens were less effective for large events, which are of greater importance for drinking water sources. These practices could increase peak instantaneous loads as a result of greater in-sewer resuspension during large events. Multiple interventions would be required to achieve the objectives of reducing the number, total volumes and peak contaminant loads of overflows upstream of drinking water intakes.

  9. The effects of combined sewer overflow events on riverine sources of drinking water.

    Science.gov (United States)

    Madoux-Humery, Anne-Sophie; Dorner, Sarah; Sauvé, Sébastien; Aboulfadl, Khadija; Galarneau, Martine; Servais, Pierre; Prévost, Michèle

    2016-04-01

    This study was set out to investigate the impacts of Combined Sewer Overflows (CSOs) on the microbiological water quality of a river used as a source of drinking water treatment plants. Escherichia coli concentrations were monitored at various stations of a river segment located in the Greater Montreal Area including two Drinking Water Intakes (DWIs) in different weather conditions (dry weather and wet weather (precipitation and snowmelt period)). Long-term monitoring data (2002-2011) at DWIs revealed good microbiological water quality with E. coli median concentrations of 20 and 30 CFU/100 mL for DWI-1 and DWI-2 respectively. However, E. coli concentration peaks reached up to 510 and 1000 CFU/100 mL for both DWIs respectively. Statistical Process Control (SPC) analysis allowed the identification of E. coli concentration peaks in almost a decade of routine monitoring data at DWIs. Almost 80% of these concentrations were linked to CSO discharges caused by precipitation exceeding 10 mm or spring snowmelt. Dry weather monitoring confirmed good microbiological water quality. Wet weather monitoring showed an increase of approximately 1.5 log of E. coli concentrations at DWIs. Cumulative impacts of CSO discharges were quantified at the river center with an increase of approximately 0.5 log of E. coli concentrations. Caffeine (CAF) was tested as a potential chemical indicator of CSO discharges in the river and CAF concentrations fell within the range of previous measurements performed for surface waters in the same area (∼20 ng/L). However, no significant differences were observed between CAF concentrations in dry and wet weather, as the dilution potential of the river was too high. CSO event based monitoring demonstrated that current bi-monthly or weekly compliance monitoring at DWIs underestimate E. coli concentrations entering DWIs and thus, should not be used to quantify the risk at DWIs. High frequency event-based monitoring is a desirable approach to

  10. Combined-sewer overflow data and methods of sample collection for selected sites, Detroit, Michigan

    Science.gov (United States)

    Sweat, M.J.; Wolf, J.R.

    1997-01-01

    The discharge of untreated sewage is illegal in Michigan unless permitted under Act 245 due to public health concerns. In October, 1992, the Michigan Department of Natural Resources (MDNR, now the Michigan Department of Environmental Quality) issued a discharge permit to Detroit authorizing discharge from the City's 78 combined-sewer overflows (CSOs), and requiring that a long-term control plan be developed to achieve mandated waterquality standards in receiving waters. The U.S. Environmental Protection Agency (USEPA) issued a national CSO policy in April, 1994, which requires (1) operational improvements of existing systems to minimize discharges and prevent their occurrence in dry weather; (2) publicly operated treatment works (POTW) to characterize the frequency and volume of discharges; and (3) construction of CSO discharge control projects where necessary.In 1993, the Southeast Michigan Council of Governments (SEMCOG) requested assistance from the U.S. Geological Survey (USGS), in cooperation with Detroit Water and Sewerage Department (DWSD) and MDNR, Surface Water Quality Division, to address part of the technical data requirements for requirement 2. The USGS scope of services for this interdisciplinary, multiagency investigation consisted of collection, compilation, and interpretation of the necessary hydrologic data, and documentation of results. In addition to USGS personnel, personnel from DWSD assisted with the field collection of samples and in alerting USGS personnel to CSO effluent discharges.From October 1, 1994 through December 31, 1995, four CSOs discharging to the Detroit River in Detroit, Michigan (figure 1) were monitored to characterize storm-related water quantity and quality. Water velocity, stage, and precipitation were measured continuously and recorded at 5-minute intervals. Water-quality samples were collected at discrete times during storms and analyzed for inorganic and organic pollutants. Discharges were sampled between 30 and 78 times

  11. Design and performance evaluation of a simplified dynamic model for combined sewer overflows in pumped sewer systems

    Science.gov (United States)

    van Daal-Rombouts, Petra; Sun, Siao; Langeveld, Jeroen; Bertrand-Krajewski, Jean-Luc; Clemens, François

    2016-07-01

    Optimisation or real time control (RTC) studies in wastewater systems increasingly require rapid simulations of sewer systems in extensive catchments. To reduce the simulation time calibrated simplified models are applied, with the performance generally based on the goodness of fit of the calibration. In this research the performance of three simplified and a full hydrodynamic (FH) model for two catchments are compared based on the correct determination of CSO event occurrences and of the total discharged volumes to the surface water. Simplified model M1 consists of a rainfall runoff outflow (RRO) model only. M2 combines the RRO model with a static reservoir model for the sewer behaviour. M3 comprises the RRO model and a dynamic reservoir model. The dynamic reservoir characteristics were derived from FH model simulations. It was found that M2 and M3 are able to describe the sewer behaviour of the catchments, contrary to M1. The preferred model structure depends on the quality of the information (geometrical database and monitoring data) available for the design and calibration of the model. Finally, calibrated simplified models are shown to be preferable to uncalibrated FH models when performing optimisation or RTC studies.

  12. Effects of wastewater and combined sewer overflows on water quality in the Blue River basin, Kansas City, Missouri and Kansas, July 1998-October 2000

    Science.gov (United States)

    Wilkison, Donald H.; Armstrong, Daniel J.; Blevins, Dale W.

    2002-01-01

    Samples were collected from 16 base-flow events and a minimum of 10 stormflow events between July 1998 and October 2000 to characterize the effects of wastewater and combined sewer overflows on water quality in the Blue River Basin, Kansas City, Missouri and Kansas. Waterquality effects were determined by analysis of nutrients, chloride, chemical and biochemical oxygen demand, and suspended sediment samples from three streams (Blue River, Brush Creek, and Indian Creek) in the basin as well as the determination of a suite of compounds known to be indicative of wastewater including antioxidants, caffeine, detergent metabolites, antimicrobials, and selected over-the-counter and prescription pharmaceuticals. Constituent loads were determined for both hydrologic regimes and a measure of the relative water-quality impact of selected stream reaches on the Blue River and Brush Creek was developed. Genetic fingerprint patterns of Escherichia coli bacteria from selected stream samples were compared to a data base of knownsource patterns to determine possible sources of bacteria. Water quality in the basin was affected by wastewater during both base flows and stormflows; however, there were two distinct sources that contributed to these effects. In the Blue River and Indian Creek, the nearly continuous discharge of treated wastewater effluent was the primary source of nutrients, wastewater indicator compounds, and pharmaceutical compounds detected in stream samples. Wastewater inputs into Brush Creek were largely the result of intermittent stormflow events that triggered the overflow of combined storm and sanitary sewers, and the subsequent discharge of untreated wastewater into the creek. A portion of the sediment, organic matter, and associated constituents from these events were trapped by a series of impoundments constructed along Brush Creek where they likely continued to affect water quality during base flow. Concentrations and loads of most wastewater constituents in

  13. Quantitative and qualitative assessment of the impact of climate change on a combined sewer overflow and its receiving water body.

    Science.gov (United States)

    Bi, Eustache Gooré; Monette, Frédéric; Gachon, Philippe; Gaspéri, Johnny; Perrodin, Yves

    2015-08-01

    Projections from the Canadian Regional Climate Model (CRCM) for the southern part of the province of Québec, Canada, suggest an increase in extreme precipitation events for the 2050 horizon (2041-2070). The main goal of this study consisted in a quantitative and qualitative assessment of the impact of the 20 % increase in rainfall intensity that led, in the summer of 2013, to overflows in the "Rolland-Therrien" combined sewer system in the city of Longueuil, Canada. The PCSWMM 2013 model was used to assess the sensitivity of this overflow under current (2013) and future (2050) climate conditions. The simulated quantitative variables (peak flow, Q(CSO), and volume discharged, VD) served as the basis for deriving ecotoxicological risk indices and event fluxes (EFs) transported to the St. Lawrence (SL) River. Results highlighted 15 to 500% increases in VD and 13 to 148% increases in Q(CSO) by 2050 (compared to 2013), based on eight rainfall events measured from May to October. These results show that (i) the relationships between precipitation and combined sewer overflow variables are not linear and (ii) the design criteria for current hydraulic infrastructure must be revised to account for the impact of climate change (CC) arising from changes in precipitation regimes. EFs discharged into the SL River will be 2.24 times larger in the future than they are now (2013) due to large VDs resulting from CC. This will, in turn, lead to excessive inputs of total suspended solids (TSSs) and tracers for numerous urban pollutants (organic matter and nutrients, metals) into the receiving water body. Ecotoxicological risk indices will increase by more than 100% by 2050 compared to 2013. Given that substantial VDs are at play, and although CC scenarios have many sources of uncertainty, strategies to adapt this drainage network to the effects of CC will have to be developed.

  14. Reducing combined sewer overflows by using outlet controls for Green Stormwater Infrastructure: Case study in Richmond, Virginia

    Science.gov (United States)

    Lucas, William C.; Sample, David J.

    2015-01-01

    Combined sewer overflows (CSOs) are a major problem in many cities. This paper assesses two Low Impact Development (LID) Green Stormwater Infrastructure (GSI) alternatives applied within a 7.05 ha catchment of the Shockoe Creek tributary of the James River in Richmond, Virginia. The LID alternatives were the "Green-Free" (typical free discharge underdrains) and the "Green-Control" (underdrains with flow controlled outlets). These alternatives were compared to two non-LID alternatives: "Existing" (existing conditions) and "Gray" (tunnel storage). A normal year scenario with average rainfall depths and intensities was compared to a scenario with anticipated higher intensity rainfall due to climate change (CC). In the normal year, the Green-Control alternative performed substantially better than both the Green-Free and the Gray alternatives in terms of volume control. However it experienced slightly more CSO events than Grey. The relative performance of both green alternatives improved with the CC climate year, indicating that GSI is more resilient than gray infrastructure. In particular, Green-Control exhibited much better performance. While the gray infrastructure solution reduced CSOs to the fewest number of occurrences, the smallest overflow volumes, lowest peak flows and the most resilient system was obtained by the Green-Control alternative. Since CSO volume is strongly related to the negative ecological impacts from overflows, and CSO occurrences are not, GSI provides a more sustainable solution than gray. These results find that hydraulic control of discharges should be the preferred option when considering GSI in CSO mitigation.

  15. Coordinated management of combined sewer overflows by means of advanced environmental decision support systems

    DEFF Research Database (Denmark)

    Murla, Damian; Gutierrez, Oriol; Martinez, Montse

    2016-01-01

    been tested in a specially designed virtual UWS, including two sewers systems, two WWTP and one river subjected to typical Mediterranean rain conditions. Results show that sewer systems, retention tanks and wastewater treatment plants improve their performance under wet weather conditions and that EDSS......During heavy rainfall, the capacity of sewer systems and wastewater treatment plants may be surcharged producing uncontrolled wastewater discharges and a depletion of the environmental quality. Therefore there is a need of advanced management tools to tackle with these complex problems...

  16. Impact of climate change and urban development scenarios on waste water overflows from the combined sewage in Nantes, France

    OpenAIRE

    Mahaut, Valérie; Andrieu, Hervé; Joannis, Claude

    2011-01-01

    In Nantes (France) important overflowings from the combined sewer network towards the Erdre, a tributary of the Loire, occur regularly and contribute to the pollution of the water resource. The present paper intends to assess the impact of climate change and of the different urban development scenarios on overflowing volumes of the sanitary sewer network in the natural environment. It proposes and discusses a method using climate model outputs at the temporal and spatial resolutions available...

  17. To what extent does variability of historical rainfall series influence extreme event statistics of sewer system surcharge and overflows?

    DEFF Research Database (Denmark)

    Schaarup-Jensen, Kjeld; Rasmussen, Michael R.; Thorndahl, Søren

    2009-01-01

    In urban drainage modelling long term extreme statistics has become an important basis for decision-making e.g. in connection with renovation projects. Therefore it is of great importance to minimize the uncertainties concerning long term prediction of maximum water levels and combined sewer...... overflow (CSO) in drainage systems. These uncertainties originate from large uncertainties regarding rainfall inputs, parameters, and assessment of return periods. This paper investigates how the choice of rainfall time series influences the extreme events statistics of max water levels in manholes and CSO...... gauges are located at a distance of max 20 kilometers from the catchment. All gauges are included in the Danish national rain gauge system which was launched in 1976. The paper describes to what extent the extreme events statistics based on these 9 series diverge from each other and how this diversity...

  18. To what extent does variability of historical rainfall series influence extreme event statistics of sewer system surcharge and overflows?

    DEFF Research Database (Denmark)

    Schaarup-Jensen, Kjeld; Rasmussen, Michael R.; Thorndahl, Søren

    2008-01-01

    In urban drainage modeling long term extreme statistics has become an important basis for decision-making e.g. in connection with renovation projects. Therefore it is of great importance to minimize the uncertainties concerning long term prediction of maximum water levels and combined sewer...... overflow (CSO) in drainage systems. These uncertainties originate from large uncertainties regarding rainfall inputs, parameters, and assessment of return periods. This paper investigates how the choice of rainfall time series influences the extreme events statistics of max water levels in manholes and CSO...... gauges are located at a distance of max 20 kilometers from the catchment. All gauges are included in the Danish national rain gauge system which was launched in 1976. The paper describes to what extent the extreme events statistics based on these 9 series diverge from each other and how this diversity...

  19. Comparing peracetic acid and hypochlorite for disinfection of combined sewer overflows: Effects of suspended-solids and pH.

    Science.gov (United States)

    McFadden, M; Loconsole, J; Schockling, A J; Nerenberg, R; Pavissich, J P

    2017-12-01

    Peracetic acid (PAA) is an alternative disinfectant that may be effective for combined sewer overflow (CSO) disinfection, but little is known about the effect of particle size on PAA disinfection efficiency. In this work, PAA and hypochlorite were compared as disinfectants, with a focus on the effect of wastewater particles. Inactivation experiments were conducted on suspended cultures of Escherichia coli and wastewater suspended solids. Tested size fractions included particle diameters solids size. However, solids size had little effect on PAA disinfection. The PAA disinfection efficiency decreased at pH values above 7.5. Live/dead staining revealed that PAA disinfection leaves most cells in a viable but non-culturable condition. Fourier transform infrared spectroscopy (FTIR) analyses suggests that PAA and hypochlorite may inactivate E. coli bacteria by similar mechanisms. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Series of surveys for enteric viruses and indicator organisms in Tokyo Bay after an event of combined sewer overflow.

    Science.gov (United States)

    Katayama, H; Okuma, K; Furumai, H; Ohgaki, S

    2004-01-01

    Combined sewer overflows (CSOs) have been recognised as one of the serious sources of pollution to the water environment during rain events, although field surveys to investigate the effect of their magnitude and duration on receiving waters have been very limited. The fates of enteric viruses (norovirus G1, G2, enteroviruses) and coliforms were determined in the wastewater treatment plant on a fine day and on a rainy day. Not all microorganisms were reduced in the primary treatment, but were reduced in the secondary treatment. Occurrences of enteric viruses and levels of coliforms were surveyed in the receiving coastal area after a CSO event, with the profiles of the enteric viruses in the coastal seawater being almost at the same positive ratio for 4 d after the CSO event.

  1. Evaluation of ecotoxicological risks related to the Discharge of Combined Sewer Overflows (CSOs) in a periurban River.

    Science.gov (United States)

    Angerville, Ruth; Perrodin, Yves; Bazin, Christine; Emmanuel, Evens

    2013-06-28

    Discharges of Combined Sewer Overflows (CSOs) into periurban rivers present risks for the concerned aquatic ecosystems. In this work, a specific ecotoxicological risk assessment methodology has been developed as management tool to municipalities equipped with CSOs. This methodology comprises a detailed description of the spatio-temporal system involved, the choice of ecological targets to be preserved, and carrying out bioassays adapted to each compartment of the river receiving CSOs. Once formulated, this methodology was applied to a river flowing through the outskirts of the city of Lyon in France. The results obtained for the scenario studied showed a moderate risk for organisms of the water column and a major risk for organisms of the benthic and hyporheic zones of the river. The methodology enabled identifying the critical points of the spatio-temporal systems studied, and then making proposals for improving the management of CSOs.

  2. Evaluation of Ecotoxicological Risks Related to the Discharge of Combined Sewer Overflows (CSOs in a Periurban River

    Directory of Open Access Journals (Sweden)

    Evens Emmanuel

    2013-06-01

    Full Text Available Discharges of Combined Sewer Overflows (CSOs into periurban rivers present risks for the concerned aquatic ecosystems. In this work, a specific ecotoxicological risk assessment methodology has been developed as management tool to municipalities equipped with CSOs. This methodology comprises a detailed description of the spatio-temporal system involved, the choice of ecological targets to be preserved, and carrying out bioassays adapted to each compartment of the river receiving CSOs. Once formulated, this methodology was applied to a river flowing through the outskirts of the city of Lyon in France. The results obtained for the scenario studied showed a moderate risk for organisms of the water column and a major risk for organisms of the benthic and hyporheic zones of the river. The methodology enabled identifying the critical points of the spatio-temporal systems studied, and then making proposals for improving the management of CSOs.

  3. Uncertainties Related to Extreme Event Statistics of Sewer System Surcharge and Overflow

    DEFF Research Database (Denmark)

    Schaarup-Jensen, Kjeld; Johansen, C.; Thorndahl, Søren Liedtke

    2005-01-01

    by performing long term simulations - using a sewer flow simulation model - and draw up extreme event statistics from the model simulations. In this context it is important to realize that uncertainties related to the input parameters of rainfall runoff models will give rise to uncertainties related...... to draw up extreme event statistics covering return periods of as much as 33 years. By comparing these two different extreme event statistics it is evident that these to a great extent depend on the uncertainties related to the input parameters of the rainfall runoff model....... proceeding in an acceptable manner, if flooding of these levels is having an average return period bigger than a predefined value. This practice is also often used in functional analysis of existing sewer systems. If a sewer system can fulfil recommended flooding frequencies or not, can only be verified...

  4. Coordinated management of combined sewer overflows by means of environmental decision support systems.

    Science.gov (United States)

    Murla, Damian; Gutierrez, Oriol; Martinez, Montse; Suñer, David; Malgrat, Pere; Poch, Manel

    2016-04-15

    During heavy rainfall, the capacity of sewer systems and wastewater treatment plants may be surcharged producing uncontrolled wastewater discharges and a depletion of the environmental quality. Therefore there is a need of advanced management tools to tackle with these complex problems. In this paper an environmental decision support system (EDSS), based on the integration of mathematical modeling and knowledge-based systems, has been developed for the coordinated management of urban wastewater systems (UWS) to control and minimize uncontrolled wastewater spills. Effectiveness of the EDSS has been tested in a specially designed virtual UWS, including two sewers systems, two WWTP and one river subjected to typical Mediterranean rain conditions. Results show that sewer systems, retention tanks and wastewater treatment plants improve their performance under wet weather conditions and that EDSS can be very effective tools to improve the management and prevent the system from possible uncontrolled wastewater discharges.

  5. Remaining Sites Verification Package for the 100-F-26:10, 1607-F3 Sanitary Sewer Pipelines (182-F, 183-F, and 151-F Sanitary Sewer Lines), Waste Site Reclassification Form 2007-028

    Energy Technology Data Exchange (ETDEWEB)

    L. M. Dittmer

    2007-12-03

    The 100-F-26:10 waste site includes sanitary sewer lines that serviced the former 182-F, 183-F, and 151-F Buildings. In accordance with this evaluation, the verification sampling results support a reclassification of this site to Interim Closed Out. The results of verification sampling show that residual contaminant concentrations do not preclude any future uses and allow for unrestricted use of shallow zone soils. The results also demonstrate that residual contaminant concentrations are protective of groundwater and the Columbia River.

  6. Remaining Sites Verification Package for the 1607-F1 Sanitary Sewer System (124-F-1) and the 100-F-26:8 (1607-F1) Sanitary Sewer Pipelines Waste Sites, Waste Site Reclassification Form 2004-130

    Energy Technology Data Exchange (ETDEWEB)

    L. M. Dittmer

    2008-03-14

    The 1607-F1 Sanitary Sewer System (124-F-1), consisted of a septic tank, drain field, and associated pipelines that received sanitary waste water from the 1701-F Gatehouse, 1709-F Fire Station, and the 1720-F Administrative Office via the 100-F-26:8 pipelines. The septic tank required remedial action based on confirmatory sampling. In accordance with this evaluation, the verification sampling results support a reclassification of this site to Interim Closed Out. The results of verification sampling show that residual contaminant concentrations do not preclude any future uses and allow for unrestricted use of shallow zone soils. The results also demonstrate that residual contaminant concentrations are protective of groundwater and the Columbia River.

  7. Remaining Sites Verification Package for the 1607-F1 Sanitary Sewer System (124-F-1) and the 100-F-26:8 (1607-F1) Sanitary Sewer Pipelines Waste Sites, Waste Site Reclassification Form 2004-130

    Energy Technology Data Exchange (ETDEWEB)

    L. M. Dittmer

    2008-03-14

    The 1607-F1 Sanitary Sewer System (124-F-1), consisted of a septic tank, drain field, and associated pipelines that received sanitary waste water from the 1701-F Gatehouse, 1709-F Fire Station, and the 1720-F Administrative Office via the 100-F-26:8 pipelines. The septic tank required remedial action based on confirmatory sampling. In accordance with this evaluation, the verification sampling results support a reclassification of this site to Interim Closed Out. The results of verification sampling show that residual contaminant concentrations do not preclude any future uses and allow for unrestricted use of shallow zone soils. The results also demonstrate that residual contaminant concentrations are protective of groundwater and the Columbia River.

  8. Constructed Wetlands for Treatment of Combined Sewer Overflow in the US: A Review of Design Challenges and Application Status

    Directory of Open Access Journals (Sweden)

    Wendong Tao

    2014-11-01

    Full Text Available As combined sewer systems and centralized wastewater treatment facilities age, many communities in the world are challenged by management of combined sewer overflow (CSO. Constructed wetlands are considered to be one of the green infrastructure solutions to CSOs in the US. Despite the wide application of constructed wetlands to different types of wastewaters, the stochastic and intermittent nature of CSO presents challenges for design and performance assessment of constructed wetlands. This paper reviews the application status of CSO constructed wetlands in the US, assesses the benefits of CSO constructed wetlands, identifies challenges to designing CSO constructed wetlands, and proposes design considerations. This review finds that constructed wetlands are effective in CSO treatment and relatively less expensive to build than comparable grey infrastructure. Constructed wetlands not only remove pollutants, but also mitigate the event-associated flow regime. The design challenges include incorporating considerations of green infrastructure into permit requirements, determining design capacity for highly variable flows, requiring pretreatment, and needing adaptive design and intensive monitoring. Simultaneous monitoring of flow rate and water quality at both the inflow and outflow of CSO constructed wetlands is required for performance assessment and needed to support design, but is rarely available.

  9. Temporal analysis of E. coli, TSS and wastewater micropollutant loads from combined sewer overflows: implications for management.

    Science.gov (United States)

    Anne-Sophie, Madoux-Humery; Dorner, Sarah M; Sauvé, Sébastien; Aboulfadl, Khadija; Galarneau, Martine; Servais, Pierre; Prévost, Michèle

    2015-05-01

    A combined sewer overflow (CSO) outfall was monitored to assess the impact of temporal mass loads on the appropriateness of treatment options. Instantaneous loads (mass per s) varied by approximately three orders of magnitude during events (n = 9 in spring, summer and the fall) with no significant seasonal variations. The median fraction of total loads discharged with the first 25% of the total volume ranged from 28% (theophylline) to 40% (Total Suspended Solids (TSS)) and loads remained high for the duration of the events. E. coli and TSS loads originated primarily from wastewater (WW) (63% and 75%, respectively). However, a mix of stormwater (SW) and sewer deposit (SD) resuspension contributed from 73 to 95% for the first 50% of the volume discharged of total TSS loads for 2 events. The contribution of SD resuspension was not negligible for Wastewater Micropollutants (WWMPs), especially for carbamazepine. Sustained high loads over the course of CSOs highlight the need to revisit current CSO and SW management strategies that focus on the treatment of early discharge volumes.

  10. Biological assessment of effects of combined sewer overflows and storm water discharges.

    NARCIS (Netherlands)

    Lijklema, L.; Roijackers, R.M.M.; Cuppen, J.G.M.

    1989-01-01

    The biological effects of discharges from combined or separated sewer systems are difficult to assess or to predict due to variahilities in concentrations, environmental conditions, morphometry, susceptibility of organisms, seasonality and other factors. A general discussion of the problem results i

  11. Remaining Sites Verification Package for the 1607-F4 Sanitary Sewer System, Waste Site Reclassification Form 2004-131

    Energy Technology Data Exchange (ETDEWEB)

    L. M. Dittmer

    2007-12-03

    The 1607-F4 waste site is the former location of the sanitary sewer system that serviced the former 115-F Gas Recirculation Building. The system included a septic tank, drain field, and associated pipeline that were in use from 1944 to 1965. The 1607-F4 waste site received unknown amounts of sanitary sewage from the 115-F Gas Recirculation Building and may have potentially contained hazardous and radioactive contamination. In accordance with this evaluation, the verification sampling results support a reclassification of this site to Interim Closed Out. The results of verification sampling demonstrated that residual contaminant concentrations do not preclude any future uses and allow for unrestricted use of shallow zone soils. The results also showed that residual contaminant concentrations are protective of groundwater and the Columbia River.

  12. Constructed Wetlands for Combined Sewer Overflow Treatment—Comparison of German, French and Italian Approaches

    Directory of Open Access Journals (Sweden)

    Daniel Meyer

    2012-12-01

    Full Text Available Combined sewer systems are designed to transport stormwater surface run off in addition to the dry weather flows up to defined limits. In most European countries, hydraulic loads greater than the design flow are discharged directly into receiving water bodies, with minimal treatment (screening, sedimentation, or with no treatment at all. One feasible solution to prevent receiving waters from strong negative impacts seems to be the application of vertical flow constructed wetlands. In Germany, first attempts to use this ecological technology were recognized in early 1990s. Since then, further development continued until a high level of treatment performance was reached. During recent years the national “state-of-the-art” (defined in 2005 was adapted in other European countries, including France and Italy. Against the background of differing national requirements in combined sewer system design, substantial developmental steps were taken. The use of coarser filter media in combination with alternating loadings of separated filter beds allows direct feedings with untreated combined runoff. Permanent water storage in deep layers of the wetland improves the system’s robustness against extended dry periods, but contains operational risks. Besides similar functions (but different designs and layouts, correct dimensioning of all approaches suffers from uncertainties in long-term rainfall predictions as well as inside sewer system simulation tools.

  13. Distribution and mobilization of pollutants in the sediment of a constructed floating wetland used for treatment of combined sewer overflow events

    OpenAIRE

    Van de Moortel, Annelies; Du Laing, Gijs; De Pauw, Niels; Tack, Filip

    2011-01-01

    Sediments in combined sewer overflow treatment systems may exhibit elevated pollutant concentrations. Concentrations measured in the sediment of a floating treatment wetland ranged from 0.17 to 1.6 (cadmium), 28 to 142 (copper), 10 to 33 (chromium), 50 to 141 (manganese), 5 to 20 (nickel), 50 to 203 (lead), and 185 to 804 (zinc) mg/kg dry matter and 7.4 to 17 (iron), 2 to 8 (total nitrogen), and 1.3 to 4.4 (total phosphorus) g/kg dry matter. During overflow events, the entering water volumes ...

  14. Sandia National Laboratories, California sewer system management plan.

    Energy Technology Data Exchange (ETDEWEB)

    Holland, Robert C.

    2010-02-01

    A Sewer System Management Plan (SSMP) is required by the State Water Resources Control Board (SWRCB) Order No. 2006-0003-DWQ Statewide General Waste Discharge Requirements (WDR) for Sanitary Sewer Systems (General Permit). DOE, National Nuclear Security Administration (NNSA), Sandia Site Office has filed a Notice of Intent to be covered under this General Permit. The General Permit requires a proactive approach to reduce the number and frequency of sanitary sewer overflows (SSOs) within the State. SSMPs must include provisions to provide proper and efficient management, operation, and maintenance of sanitary sewer systems and must contain a spill response plan. Elements of this Plan are under development in accordance with the SWRCB's schedule.

  15. Monitoring and analysis of combined sewer overflows, Riverside and Evanston, Illinois, 1997-99

    Science.gov (United States)

    Waite, Andrew M.; Hornewer, Nancy J.; Johnson, Gary P.

    2002-01-01

    The U.S. Geological Survey, in cooperation with the U.S. Army Corps of Engineers, collected and analyzed flow data in combined sewer systems in Riverside and Evanston, northeastern Illinois, from March 1997 to December 1999. Continuous 2- and 5-minute stage and velocity data were collected during surcharged and nonsurcharged conditions at 12 locations. Mass balances were calculated to determine the volume of water flowing through the tide-gate openings to the Des Plaines River and the North Shore Channel and to determine the volume of water flowing past the sluice gate to the deep tunnel. The sewer systems consist of circular pipes ranging in diameter from 0.83 feet to 10.0 feet, elliptical siphon pipes, ledges, and tide and sluice gates. Pipes were constructed of either brick and mortar or concrete, and ranged from having smooth surfaces to rough, pitted and crumbling surfaces. One pipe was noticeably affected by water infiltration from saturated ground. During data analysis, many assumptions were necessary because of the complexity of the flow data and sewer-system configurations. These assumptions included estimating the volume of water entering an interceptor sewer at the ''Gage Street pipe'' at Riverside, the effect of infiltration on the ''brick pipe'' at Riverside, and the minimum velocity required for the meter to make an accurate velocity determination. Other factors affecting the analysis of flow data included possible non-instrumented sources of inflow, and backwater conditions in some pipes, which could have caused error in the data analysis. Variations of these assumptions potentially could cause appreciable changes to the final massbalance calculations. Mass-balance analysis at Riverside indicated a total inflow volume into chamber 3 of approximately 721,000 cubic feet (ft3) during April 22-26, 1999. Outflow volume to the Des Plaines River at Riverside through the tide gate was approximately 132,000 ft3; outflow volume to the deep tunnel through the

  16. Impacts of combined sewer overflows on a large urban river - Understanding the effect of different management strategies.

    Science.gov (United States)

    Riechel, Mathias; Matzinger, Andreas; Pawlowsky-Reusing, Erika; Sonnenberg, Hauke; Uldack, Mathias; Heinzmann, Bernd; Caradot, Nicolas; von Seggern, Dörthe; Rouault, Pascale

    2016-11-15

    To support decision makers in planning effective combined sewer overflow (CSO) management strategies an integrated modelling and impact assessment approach has been developed and applied for a large urban area in Berlin, Germany. It consists of an urban drainage model, a river water quality model and a tool for the quantification of adverse dissolved oxygen (DO) conditions in the river, one of the main stressors for urban lowland rivers. The coupled model was calibrated successfully with average Nash-Sutcliffe-efficiencies for DO in the river of 0.61 and 0.70 for two validation years. Moreover, the whole range of observed DO concentrations after CSO down to 0 mg L(-1) is simulated by the model. A local sensitivity analysis revealed that in the absence of CSO dissolved oxygen principally depends on phytoplankton dynamics. Regarding CSO impacts, it was shown that 97% of the observed DO deficit can be explained by the three processes (i) mixing of river water with CSO spill water poor in DO, (ii) reduced phytoplankton activity due to CSO-induced turbidity and (iii) degradation of organic matter by heterotrophic bacteria. As expected, process (iii) turned out to be the most important one. However depending on the time lag after CSO the other processes can become dominant. Given the different involved processes, we found that different mitigation schemes tested in a scenario analysis can reduce the occurrence of critical DO deficits in the river by 30-70%. Overall, the study demonstrates that integrated sewer-river-models can be set up to represent CSO impacts under complex urban conditions. However, a significant effort in monitoring and modelling is a requisite for achieving reliable results.

  17. Assessment of the ecotoxicological risk of combined sewer overflows for an aquatic system using a coupled "substance and bioassay" approach.

    Science.gov (United States)

    Gooré Bi, Eustache; Monette, Frederic; Gasperi, Johnny; Perrodin, Yves

    2015-03-01

    Very few tools are available for assessing the impact of combined sewer overflows (CSOs) on receiving aquatic environments. The main goal of the study was to assess the ecotoxicological risk of CSOs for a surface aquatic ecosystem using a coupled "substance and bioassay" approach. Wastewater samples from the city of Longueuil, Canada CSO were collected for various rainfall events during one summer season and analyzed for a large panel of substances (n = 116). Four bioassays were also conducted on representative organisms of surface aquatic systems (Pimephales promelas, Ceriodaphnia dubia, Daphnia magna, and Oncorhynchus mykiss). The analytical data did not reveal any ecotoxicological risk for St. Lawrence River organisms, mainly due to strong effluent dilution. However, the substance approach showed that, because of their contribution to the ecotoxicological hazard posed by the effluent, total phosphorus (Ptot), aluminum (Al), total residual chlorine, chromium (Cr), copper (Cu), pyrene, ammonia (N-NH4 (+)), lead (Pb), and zinc (Zn) require more targeted monitoring. While chronic ecotoxicity tests revealed a potential impact of CSO discharges on P. promelas and C. dubia, acute toxicity tests did not show any effect on D. magna or O. mykiss, thus underscoring the importance of chronic toxicity tests as part of efforts aimed at characterizing effluent toxicity. Ultimately, the study leads to the conclusion that the coupled "substance and bioassay" approach is a reliable and robust method for assessing the ecotoxicological risk associated with complex discharges such as CSOs.

  18. Deep Tunnel for Regulating Combined Sewer Overflow Pollution and Flood Disaster: A Case Study in Guangzhou City, China

    Directory of Open Access Journals (Sweden)

    Haichun Wu

    2016-08-01

    Full Text Available The DongHaoChong (DHC basin is located in the central city zone of Guangzhou City, China. Owing to the high density of buildings and low quality of the drainage pipe network in the city, diversion of rain and sewage is difficult. Waterlogging occurs frequently and combined sewer overflow (CSO pollution is a serious problem during the rainy season. Therefore, a deep tunnel for the DongHaoChong basin has been planned and its construction is currently underway. An urban rainstorm model for the DongHaoChong basin was developed on the basis of the Storm Water Management Model (SWMM, and both the interception effect of CSO pollution and the degree of mitigation of flood were analyzed. Reasonable scenarios for the deep tunnel in terms of rainstorms with different design recurrence periods were evaluated. From the viewpoints of preventing rainstorm waterlogging disasters and protecting water quality in the region downstream of DongHaoChong River, the river flood control and drainage capacities of the region were improved to a 2-year rainstorm design recurrence period by the construction of the deep tunnel. Furthermore, the main pollutant load of the CSO is expected to be reduced by about 30%–40%.

  19. Nitrogen patterns in subsurface waters of the Yzeron stream: effect of combined sewer overflows and subsurface-surface water mixing.

    Science.gov (United States)

    Aucour, A M; Bariac, T; Breil, P; Namour, P; Schmitt, L; Gnouma, R; Zuddas, P

    2013-01-01

    Urbanization subjects streams to increased nitrogen loads. Therefore studying nitrogen forms at the interface between urban stream and groundwater is important for water resource management. In this study we report results on water δ(18)O and nitrogen forms in subsurface waters of a stream (Yzeron, France). The sites studied were located upstream and downstream of combined sewer overflows (CSO) in a rural area and a periurban area, respectively. Water δ(18)O allowed us to follow the mixing of subsurface water with surface water. Dissolved organic nitrogen and organic carbon of fine sediment increased by 20-30% between rural and periurban subsurface waters in the cold season, under high flow. The highest nitrate levels were observed in rural subsurface waters in the cold season. The lowest nitrate levels were found in periurban subsurface waters in the warm season, under low flow. They corresponded to slow exchange of subsurface waters with channel water. Thus reduced exchange between surface and subsurface waters and organic-matter-rich input seemed to favor nitrate reduction in the downstream, periurban, subsurface waters impacted by CSO.

  20. Effects of rainfall events on the occurrence and detection efficiency of viruses in river water impacted by combined sewer overflows.

    Science.gov (United States)

    Hata, Akihiko; Katayama, Hiroyuki; Kojima, Keisuke; Sano, Shoichi; Kasuga, Ikuro; Kitajima, Masaaki; Furumai, Hiroaki

    2014-01-15

    Rainfall events can introduce large amount of microbial contaminants including human enteric viruses into surface water by intermittent discharges from combined sewer overflows (CSOs). The present study aimed to investigate the effect of rainfall events on viral loads in surface waters impacted by CSO and the reliability of molecular methods for detection of enteric viruses. The reliability of virus detection in the samples was assessed by using process controls for virus concentration, nucleic acid extraction and reverse transcription (RT)-quantitative PCR (qPCR) steps, which allowed accurate estimation of virus detection efficiencies. Recovery efficiencies of poliovirus in river water samples collected during rainfall events (10%). The log10-transformed virus concentration efficiency was negatively correlated with suspended solid concentration (r(2)=0.86) that increased significantly during rainfall events. Efficiencies of DNA extraction and qPCR steps determined with adenovirus type 5 and a primer sharing control, respectively, were lower in dry weather. However, no clear relationship was observed between organic water quality parameters and efficiencies of these two steps. Observed concentrations of indigenous enteric adenoviruses, GII-noroviruses, enteroviruses, and Aichi viruses increased during rainfall events even though the virus concentration efficiency was presumed to be lower than in dry weather. The present study highlights the importance of using appropriate process controls to evaluate accurately the concentration of water borne enteric viruses in natural waters impacted by wastewater discharge, stormwater, and CSOs.

  1. Sewer Systems and Climate Change

    NARCIS (Netherlands)

    Brandsma, T.

    1993-01-01

    In this article the impact of climate change on the overflows of sewer systems is assessed. The emphasis is on the overflows of combined sewer systems. The purpose is twofold: first, to obtain a first-order estimate of the impact of climate change on overflows of sewer systems; and second, to obtain

  2. Management of combined sewer overflows based on observations from the urbanized Liguori catchment of Cosenza, Italy.

    Science.gov (United States)

    Piro, P; Carbone, M; Garofalo, G; Sansalone, J J

    2010-01-01

    This paper examines an urbanized catchment in Cosenza, Italy where an off-line basin intercepting CSOs was studied to illustrate reduction in CSO discharges to the Crati River. While the hydrologic transport of pollutant mass is never known a-priori and can be flow-limited, the volumetric requirements of the basin were modeled based on the classic assumption that wet weather flows transport urban and sewer loads in a mass-limited (first-flush) delivery. The volumetric capacity of the basin was varied from 10 to 50 m(3)/ha. Operational basin control was simulated with historical datasets from the Liguori catchment, event-based loading data, and continuous simulation modelling with SWMM. Utilizing data from the catchment, the SWMM simulations were conducted considering the storage basin with or without sedimentation treatment. Results illustrate the potential benefits of the off-line operation for the system with respect to the volume and mass reduction of CSOs into the Crati River. Results demonstrate the importance of particle size distribution (PSD) as an index of basin efficiency, coupled with analysis of the hydrodynamic response of the basin. The basin model attenuated influent PSDs, separating the coarser fraction of the PSD, and reduced the load of influent particulate matter (PM).

  3. An elutriation apparatus for assessing settleability of combined sewer overflows (CSOs).

    Science.gov (United States)

    Marsalek, J; Krishnappan, B G; Exall, K; Rochfort, Q; Stephens, R P

    2006-01-01

    An elutriation apparatus was proposed for testing the settleability of combined sewer outflows (CSOs) and applied to 12 CSO samples. In this apparatus, solids settling is measured under dynamic conditions created by flow through a series of settling chambers of varying diameters and upward flow velocities. Such a procedure reproduces better turbulent settling in CSO tanks than the conventional settling columns, and facilitates testing coagulant additions under dynamic conditions. Among the limitations, one could name the relatively large size of the apparatus and samples (60 L), and inadequate handling of floatables. Settleability results obtained for the elutriation apparatus and a conventional settling column indicate large inter-event variation in CSO settleability. Under such circumstances, settling tanks need to be designed for "average" conditions and, within some limits, the differences in test results produced by various settleability testing apparatuses and procedures may be acceptable. Further development of the elutriation apparatus is under way, focusing on reducing flow velocities in the tubing connecting settling chambers and reducing the number of settling chambers employed. The first measure would reduce the risk of floc breakage in the connecting tubing and the second one would reduce the required sample size.

  4. Predicting Air-Water Geysers and Their Implications on Reducing Combined Sewer Overflows

    Science.gov (United States)

    Choi, Y.; Leon, A.; Apte, S.

    2014-12-01

    An air-water geyser in a closed conduit system is characterized by an explosive jetting of a mixture of air and water through drop-shafts. In this study, three scenarios of geysers are numerically simulated using a 3D computational fluid dynamics (CFD) model. The three tested scenarios are comprised of a drop shaft that is closed at its bottom and partially or fully open at the top. Initially, the lower section of the drop shaft is filled with pressurized air, the middle section with stagnant water and the upper section with air at atmospheric pressure. The pressure and volume of the pressurized air, and hence the stored energy, is different for all three test cases. The volume of the stagnant water and the air at atmospheric pressure are kept constant in the tests. The numerical simulations aim to identify the correlation between dimensionless energy stored in the pressurized air pocket and dimensionless maximum pressure reached at the outlet. This dimensionless correlation could be used to determine the energy threshold that does not produce air-water geyser, which in turn could be used in the design of combined sewer systems for minimizing geysers.

  5. Impacts of global change on the concentrations and dilution of combined sewer overflows in a drinking water source.

    Science.gov (United States)

    Jalliffier-Verne, Isabelle; Leconte, Robert; Huaringa-Alvarez, Uriel; Madoux-Humery, Anne-Sophie; Galarneau, Martine; Servais, Pierre; Prévost, Michèle; Dorner, Sarah

    2015-03-01

    This study presents an analysis of climate change impacts on a large river located in Québec (Canada) used as a drinking water source. Combined sewer overflow (CSO) effluents are the primary source of fecal contamination of the river. An analysis of river flowrates was conducted using historical data and predicted flows from a future climate scenario. A spatio-temporal analysis of water quality trends with regard to fecal contamination was performed and the effects of changing flowrates on the dilution of fecal contaminants were analyzed. Along the river, there was a significant spatial trend for increasing fecal pollution downstream of CSO outfalls. Escherichia coli concentrations (upper 95th percentile) increased linearly from 2002 to 2012 at one drinking water treatment plant intake. Two critical periods in the current climate were identified for the drinking water intakes considering both potential contaminant loads and flowrates: local spring snowmelt that precedes river peak flow and extra-tropical storm events that occur during low flows. Regionally, climate change is expected to increase the intensity of the impacts of hydrological conditions on water quality in the studied basin. Based on climate projections, it is expected that spring snowmelt will occur earlier and extreme spring flowrates will increase and low flows will generally decrease. High and low flows are major factors related to the potential degradation of water quality of the river. However, the observed degradation of water quality over the past 10 years suggests that urban development and population growth may have played a greater role than climate. However, climate change impacts will likely be observed over a longer period. Source water protection plans should consider climate change impacts on the dilution of contaminants in addition to local land uses changes in order to maintain or improve water quality.

  6. Determination of micropollutants in combined sewer overflows and their removal in a wastewater treatment plant (Seoul, South Korea).

    Science.gov (United States)

    Ryu, Jaena; Oh, Jeill; Snyder, Shane A; Yoon, Yeomin

    2014-05-01

    The present study investigated the occurrence of 29 selected micropollutants such as endocrine disrupting compounds (EDCs) and pharmaceuticals and personal care products (PPCPs) in surface waters and wastewaters in Seoul (South Korea) during both dry and wet weather conditions. The study area was selected based on the lack of available information regarding the suspected contamination of rivers/creeks by EDCs and PPCPs in the Seoul region and the presence of a wastewater treatment plant (WWTP), which serves approximately 4.1 million inhabitants and has a design capacity of 1,297 × 10(3) m(3)/day. Many target compounds (83 %) were detected in samples collected from wastewater treatment influent/effluent, creek water, and combined sewer overflow (CSO). The total EDC/PPCP concentrations were as follows: WWTP influent (69,903 ng/L) > WWTP effluent (50,175 ng/L) >3 creek samples (16,035-44,446 ng/L) during dry weather, and WWTP influent (53,795 ng/L) > WWTP bypass (38,653 ng/L) >5 creek samples (15,260-29,113 ng/L) >2 CSO samples (11,109-11,498 ng/L) during wet weather. EDCs and PPCPs were found to be present at high daily loads (65.1 and 69.8 kg/day during dry and wet weather, respectively) in the WWTP effluent. Compound removal by the WWTP varied significantly by compound: caffeine, diclofenac, ibuprofen, naproxen, and propylparaben (>90 %), and acesulfame, DEET, iohexol, iopromide, and iopamidol (<5 %). These findings and literature information support the hypothesis that the efficiency of removal of EDCs and PPCPs is strongly dependent on both removal mechanism (e.g., biodegradation, adsorption to sludge, and oxidation by chlorine) and compound physicochemical properties (e.g., pK a and hydrophobicity).

  7. Dynamics of toxicity within different compartments of a peri-urban river subject to combined sewer overflow discharges.

    Science.gov (United States)

    Becouze-Lareure, C; Thiebaud, L; Bazin, C; Namour, P; Breil, P; Perrodin, Y

    2016-01-01

    Combined Sewer Overflows (CSO) in small peri-urban streams and rivers are potentially toxic for their biocenosis. Improving the management of CSO discharges requires better knowledge of their dynamics and toxicity. In view to characterizing this toxicity, we sampled the different compartments (benthic and hyporheic zone) of a peri-urban stream located near the city of Lyon in France. The samples were taken at different distances from a CSO and at three period characteristic of different hydrological conditions. Their toxic effects were assessed by bioassays on the dissolved fraction (D. magna, V. fisheri and B. calyciflorus bioassays) and on the particle fraction (V. fisheri and H. incongruens bioassays). The results highlighted significant toxicity of the particulate fraction for the benthic and hyporheic samples, in particular downstream of the CSO, but with high spatio-temporal variability. This variability can first be attributed to the variability of CSO discharge sampling as a function of season and rainfall, and the dynamics of polluted particles (trapping of transported particles in infiltration zones, mobilization during floods). These parameters play a fundamental role in the distribution of pollutants according to the geomorphology of stream facies. Regarding dissolved pollutants, the chemical exchanges taking place at the "water-sediment" interface trigger the transfer of pollutants from one phase to another, after which the dispersion of these pollutants is governed by hydraulic flows. Finally, critical zones and periods are identified for the peri-urban river toxicity studied: benthic sediments under mean flow downstream; hyporheic sediments after a storm event downstream, close to the CSO. Recommendations are made on the basis of the knowledge obtained to optimize the management of these discharges.

  8. Resilience of sewage services to climate change uncertainty: analysis of the management of sewer overflows in two Parisian suburban areas.

    Science.gov (United States)

    Rioust, E.; Deroubaix, J. F.; Barroca, B.; Bonierbale, T.; de Gouvello, B.; Deutsch, J. C.; Hubert, G.

    2009-04-01

    This paper considers the resilience perspective as an approach for understanding social and political vulnerabilities of urban services. The authors examine to what extend uncertainty due to climate change may affect the resilience of these urban services. The resilience perspective is increasingly used for analysing social groups' capacities to adapt to and live with disturbances. A lot of work on resilience has focused on the capacity to absorb shocks and still maintain functions. But there is also another aspect of resilience, which leads to take into account systems vulnerabilities and to aim at understanding their equilibrium and re-organization capacity. The purpose with this paper is to assess sewage systems capacities to adapt to climate change. Indeed, climate change could cause an increase of extreme rain events and, as a matter of consequence, an increase of sewer overflows and flooding of urbanised areas. Sewer systems have to cope with this change that may gravely affect urban planning. In recent studies of political science, risk management has been considered as a public policy involving and resulting from complex social, political and technical processes (Gilbert et al. 2003). From this point of view, the management of wastewaters and storm waters has to be considered not only as a technical but also as a political and a social system. Therefore, political science can be a fruitful perspective to understand the stakeholders perceptions of uncertainty and the way they are going to integrate this issue in their practices. The authors analyse the adaptive capacities of two sewer systems located in the Parisian suburban area. The chosen areas are highly populated. Each network is managed within a political and administrative unit called "Département". Both authorities of these "Départements" implement a public sewage service. Nonetheless these networks are connected and part of the greater Paris sewage policy. In both areas a real time control of

  9. Watershed-scale impacts of stormwater green infrastructure on hydrology, nutrient fluxes, and combined sewer overflows in the mid-Atlantic region.

    Science.gov (United States)

    Pennino, Michael J; McDonald, Rob I; Jaffe, Peter R

    2016-09-15

    Stormwater green infrastructure (SGI), including rain gardens, detention ponds, bioswales, and green roofs, is being implemented in cities across the globe to reduce flooding, combined sewer overflows, and pollutant transport to streams and rivers. Despite the increasing use of urban SGI, few studies have quantified the cumulative effects of multiple SGI projects on hydrology and water quality at the watershed scale. To assess the effects of SGI, Washington, DC, Montgomery County, MD, and Baltimore County, MD, were selected based on the availability of data on SGI, water quality, and stream flow. The cumulative impact of SGI was evaluated over space and time by comparing watersheds with and without SGI, and by assessing how long-term changes in SGI impact hydrologic and water quality metrics over time. Most Mid-Atlantic municipalities have a goal of achieving 10-20% of the landscape drain runoff through SGI by 2030. Of these areas, Washington, DC currently has the greatest amount of SGI (12.7% of the landscape drained through SGI), while Baltimore County has the lowest (7.9%). When controlling for watersheds size and percent impervious surface cover, watersheds with greater amounts of SGI have less flashy hydrology, with 44% lower peak runoff, 26% less frequent runoff events, and 26% less variable runoff. Watersheds with more SGI also show 44% less NO3(-) and 48% less total nitrogen exports compared to watersheds with minimal SGI. There was no significant reduction in phosphorus exports or combined sewer overflows in watersheds with greater SGI. When comparing individual watersheds over time, increases in SGI corresponded to non-significant reductions in hydrologic flashiness compared to watersheds with no change in SGI. While the implementation of SGI is somewhat in its infancy in some regions, cities are beginning to have a scale of SGI where there are statistically significant differences in hydrologic patterns and water quality.

  10. Remaining Sites Verification Package for the 100-C-9:2 Sanitary Sewer Pipelines, Waste Site Reclassification Form 2004-013

    Energy Technology Data Exchange (ETDEWEB)

    L. M. Dittmer

    2007-07-11

    The 100-C-9:2 sanitary sewer pipelines include the feeder pipelines associated with the 1607-B8, the 1607-B9, the 1607-B10 and the 1607-B11 septic systems. Contaminated soil and piping from the feeder lines to the septic systems were removed and disposed of. The remaining soil in the excavations has been shown to meet the remedial action objectives specified in the Remaining Sites ROD. The results of verification sampling show that residual contaminant concentrations do not preclude any future uses and allow for unrestricted use of shallow zone soils. The results also demonstrate that residual contaminant concentrations are protective of groundwater and the Columbia River.

  11. Evaluation of Green Alternatives for Combined Sewer Overflow Mitigation: A Proposed Economic Impact Framework and Illustration of its Application

    Science.gov (United States)

    This report develops a broad framework, or taxonomy, for identifying and organizing the socio-economic impacts of sewer infrastructure projects. It focuses on a green project in Cincinnati, Ohio that has adopted broader economic goals. The report then uses this example to illustr...

  12. Distribution and mobilization of pollutants in the sediment of a constructed floating wetland used for treatment of combined sewer overflow events.

    Science.gov (United States)

    Van de Moortel, Annelies M K; Du Laing, Gijs; De Pauw, Niels; Tack, Filip M G

    2011-05-01

    Sediments in combined sewer overflow treatment systems may exhibit elevated pollutant concentrations. Concentrations measured in the sediment of a floating treatment wetland ranged from 0.17 to 1.6 (cadmium), 28 to 142 (copper), 10 to 33 (chromium), 50 to 141 (manganese), 5 to 20 (nickel), 50 to 203 (lead), and 185 to 804 (zinc) mg/kg dry matter and 7.4 to 17 (iron), 2 to 8 (total nitrogen), and 1.3 to 4.4 (total phosphorus) g/kg dry matter. During overflow events, the entering water volumes can disturb the sediments. A greenhouse experiment was set up to evaluate the possible mobilization of pollutants through disturbation. The disturbation did not result in an increased mobilization of cadmium, copper, chromium, nickel, lead, zinc, nitrogen, phosphorus, and organic carbon towards the pore and surface water. Calcium concentrations in the surface water increased for all sediments, as a result of release from the exchangeable sediment pool and dissolution of carbonates. Geochemical speciation modeling indicated that, in the pore water, the free ion form was the most abundant for calcium, iron, manganese, cadmium, and nickel, with its fraction increasing with time.

  13. Water quality deterioration at a karst spring (Gallusquelle, Germany) due to combined sewer overflow: evidence of bacterial and micro-pollutant contamination

    Science.gov (United States)

    Heinz, B.; Birk, S.; Liedl, R.; Geyer, T.; Straub, K. L.; Andresen, J.; Bester, K.; Kappler, A.

    2009-04-01

    The concurrent use of karst aquifers as drinking water resources and receptors of combined sewer overflow lacking appropriate pre-treatment may cause conflicts between drinking water supply and storm water management. A storm water tank (SWT) for combined wastewater is identified as the source of sporadic contamination of a karst spring (Gallusquelle, “Schwäbische Alb”, SW Germany) used for public water supply. Spring water quality was examined by routine and event sampling and by evaluating physicochemical and microbiological parameters. The total number of microbial colonies growing at 20°C and the number of Escherichia coli colonies rose to values up to four orders of magnitude higher than background, 2-5 days after overflow of the SWT. High concentrations of chloride, sodium, and total organic carbon (TOC) and high values of turbidity coincide with this increase. However, high bacterial contamination is also observed while turbidity and TOC are low. Several wastewater-related organic micro-pollutants such as chlorinated and non-chlorinated organophosphates were detected in the SWT and, depending on their K ow values and their biodegradability, in lower concentrations at the spring.

  14. Determining the spill flow discharge of combined sewer overflows using rating curves based on computational fluid dynamics instead of the standard weir equation.

    Science.gov (United States)

    Fach, S; Sitzenfrei, R; Rauch, W

    2009-01-01

    It is state of the art to evaluate and optimise sewer systems with urban drainage models. Since spill flow data is essential in the calibration process of conceptual models it is important to enhance the quality of such data. A wide spread approach is to calculate the spill flow volume by using standard weir equations together with measured water levels. However, these equations are only applicable to combined sewer overflow (CSO) structures, whose weir constructions correspond with the standard weir layout. The objective of this work is to outline an alternative approach to obtain spill flow discharge data based on measurements with a sonic depth finder. The idea is to determine the relation between water level and rate of spill flow by running a detailed 3D computational fluid dynamics (CFD) model. Two real world CSO structures have been chosen due to their complex structure, especially with respect to the weir construction. In a first step the simulation results were analysed to identify flow conditions for discrete steady states. It will be shown that the flow conditions in the CSO structure change after the spill flow pipe acts as a controlled outflow and therefore the spill flow discharge cannot be described with a standard weir equation. In a second step the CFD results will be used to derive rating curves which can be easily applied in everyday practice. Therefore the rating curves are developed on basis of the standard weir equation and the equation for orifice-type outlets. Because the intersection of both equations is not known, the coefficients of discharge are regressed from CFD simulation results. Furthermore, the regression of the CFD simulation results are compared with the one of the standard weir equation by using historic water levels and hydrographs generated with a hydrodynamic model. The uncertainties resulting of the wide spread use of the standard weir equation are demonstrated.

  15. Assessing changes in the Presque Isle Bay watershed fish community using a modified index of biotic integrity: before and after the elimination of combined sewer overflows.

    Science.gov (United States)

    Rafferty, Sean D; Lybrook, Jake; Kaczmarek, Karla M; Lethaby, Mark; Wellington, Robert; Pyron, Mark

    2013-12-01

    An index of biotic integrity and species richness were used to assess changes in the Presque Isle Bay watershed fish community before and after the elimination of combined sewer overflows (CSOs). The fish community was sampled with a backpack electrofisher in 2011 at 12 stream locations on 4 tributaries of Presque Isle Bay, Erie County, Pennsylvania. All sites were previously sampled in 2001. Significant increases in species richness and index of biotic integrity (IBI) scores were observed in 2011 compared to 2001. The significant increases in species richness and IBI scores occurred following the elimination of 10 CSOs to Garrison Run, 7 CSOs to Cascade Creek, and 37 CSOs to Mill Creek. Despite the increased richness and IBI scores, the fish community remains in poor condition, which may be related to the highly urbanized land use of the watershed. Urban land uses comprise 77% of the Presque Isle Bay watershed, and in both 2011 and 2001, the watershed as a whole did not meet warm-water habitat criteria. It is unlikely that the fish community will continue to recover without addressing urbanization throughout the watershed.

  16. Remaining Sites Verification Package for the 1607-B2 Septic System and 100-B-14:2 Sanitary Sewer System, Waste Site Reclassification Form 2004-006

    Energy Technology Data Exchange (ETDEWEB)

    L. M. Dittmer

    2007-03-21

    The 100-B-14:2 subsite encompasses the former sanitary sewer feeder lines associated with the 1607-B2 and 1607-B7 septic systems. Feeder lines associated with the 185/190-B building have also been identified as the 100-B-14:8 subsite, and feeder lines associated with the 1607-B7 septic system have also been identified as the 100-B-14:9 subsite. These two subsites have been administratively cancelled to resolve the redundancy. The results of verification sampling show that residual contaminant concentrations do not preclude any future uses and allow for unrestricted use of shallow zone soils. The results also demonstrate that residual contaminant concentrations are protective of groundwater and the Columbia River.

  17. Remaining Sites Verification Package for the 100-F-26:9, 1607-F2 Sanitary Sewer Pipelines, Waste Site Reclassification Form 2008-029

    Energy Technology Data Exchange (ETDEWEB)

    J. M. Capron

    2008-10-29

    The 100-F-26:9 underground pipeline subsite consists of the sanitary sewers servicing the 105-F, 108-F, 184-F, 185-F, and 190-F buildings, and the 1700-F administration and service buildings (1704-F, 1707-F, 1707-FA, 1713-F, 1717-F, 1719-F, and 1722-F). In accordance with this evaluation, the confirmatory and verification sampling results support a reclassification of this site to Interim Closed Out. The current site conditions achieve the remedial action objectives and the corresponding remedial action goals established in the Remaining Sites ROD. The results of verification sampling show that residual contaminant concentrations do not preclude any future uses and allow for unrestricted use of shallow zone soils. The results also demonstrate that residual contaminant concentrations are protective of groundwater and the Columbia River.

  18. Three-dimensional model to capture the fate and transport of combined sewer overflow discharges: A case study in the Chicago Area Waterway System.

    Science.gov (United States)

    Quijano, Juan C; Zhu, Zhenduo; Morales, Viviana; Landry, Blake J; Garcia, Marcelo H

    2017-01-15

    We used a numerical model to analyze the impact of combined sewer overflows (CSOs) in the hydrodynamics and water quality of the Chicago Area Waterway System (CAWS). We coupled the Environmental Fluid Dynamics Code (EFDC) with the Water Quality Analysis Simulation Program (WASP) to perform three-dimensional simulations of the hydrodynamics and water quality in CAWS. The analysis was performed for two different storms: (i) May 6, 2009 representing a 6-hour duration 4-month return period, and (ii) September 12, 2008 representing a 48-hour duration 100-year return period. Results from the simulations show distinct differences between the two storms. During the May 2009 storm there was only one major CSO pumping event with negligible impact on the water quality of CAWS. During the September 2008 storm there were several CSOs that impacted the hydrodynamics and water quality of CAWS. In particular, CSOs during the September 2008 event induced a reversal flow in CAWS, with a plume of constituents that traveled in the opposite direction as water does under normal conditions. However, the simulation results show that CSOs events in CAWS take place during periods of high rainfall, thus the discharge of CSOs is significantly diluted along the CAWS. As a result, the concentrations of organic matter and inorganic nutrients observed at the downstream boundary in CAWS were significantly lower than those recorded at the CSOs outfalls and are within the limits established in the regulation for regular effluents. These results suggest that even during storms events with significant CSOs into the CAWS there is a significant dilution that reduce the impact in the water quality at the system boundaries.

  19. Remaining Sites Verification Package for the 1607-F1 Sanitary Sewer System (124-F-1) and the 100-F-26:8 (1607-F1) Sanitary Sewer Pipelines Waste Sites, Waste Site Reclassification Form 2005-004

    Energy Technology Data Exchange (ETDEWEB)

    L. M. Dittmer

    2008-03-14

    The 100-F-26:8 waste site consisted of the underground pipelines that conveyed sanitary waste water from the 1701-F Gatehouse, 1709-F Fire Station, and the 1720-F Administrative Office to the 1607-F1 septic tank. The site has been remediated and presently exists as an open excavation. In accordance with this evaluation, the verification sampling results support a reclassification of this site to Interim Closed Out. The results of verification sampling demonstrated that residual contaminant concentrations do not preclude any future uses and allow for unrestricted use of shallow zone soils. The results also showed that residual contaminant concentrations are protective of groundwater and the Columbia River.

  20. Remaining Sites Verification Package for the 1607-F1 Sanitary Sewer System (124-F-1) and the 100-F-26:8 (1607-F1) Sanitary Sewer Pipelines Waste Sites, Waste Site Reclassification Form 2005-004

    Energy Technology Data Exchange (ETDEWEB)

    L. M. Dittmer

    2008-03-14

    The 100-F-26:8 waste site consisted of the underground pipelines that conveyed sanitary waste water from the 1701-F Gatehouse, 1709-F Fire Station, and the 1720-F Administrative Office to the 1607-F1 septic tank. The site has been remediated and presently exists as an open excavation. In accordance with this evaluation, the verification sampling results support a reclassification of this site to Interim Closed Out. The results of verification sampling demonstrated that residual contaminant concentrations do not preclude any future uses and allow for unrestricted use of shallow zone soils. The results also showed that residual contaminant concentrations are protective of groundwater and the Columbia River.

  1. Sewer Systems and Climate Change

    OpenAIRE

    Brandsma, T.

    1993-01-01

    In this article the impact of climate change on the overflows of sewer systems is assessed. The emphasis is on the overflows of combined sewer systems. The purpose is twofold: first, to obtain a first-order estimate of the impact of climate change on overflows of sewer systems; and second, to obtain insight into the relevant meteorological variables that are important with respect to climate change. A reservoir model is used to assess the impact of climate change on several combinations of st...

  2. 考虑暴雨重现期下雨水管网溢流的优化理论初探%Optimization of Overflow from Storm Sewer System Based on Storm Return Period

    Institute of Scientific and Technical Information of China (English)

    王赫婧; 张志成; 尤学一; 季民

    2012-01-01

    According to Tianjin Municipal Engineering Budget Price, a model for construction cost of storm sewer system was built. Five low-cost schemes were found by enumeration algorithm and by applying global search under given conditions of design flow, original buried depth and length of pipe. The cost of these five schemes decreased by 10. 13% , 9. 47% , 6. 25% , 5. 57% and 4. 82% respectively compared with the originally planned scheme. The overflows of the above five schemes in different storm return periods were simulated by SWMM. The quantitative relations of overflow risk to storm return periods and structure of storm sewer system were determined. All six schemes would lead to node overflow, pipe overload and high load of pipe drainage in different return periods except for 0. 5 a.%以《天津市市政工程预算基价》为基础,建立了雨水管网建设费用模型,并在给定设计流量、起始管埋深和管长条件下,利用枚举算法,全局搜索出造价较优的5种设计方案,且这5种方案的造价分别比规划方案低了10.13%、9.47%、6.25%、5.57%、4.82%.利用SWMM模型模拟了优选方案在不同降雨重现期下的溢流情况,确定了溢流风险与暴雨重现期和管网结构之间的定量关系.结果表明,包括规划方案在内的6种方案,在除0.5年外的其他不同重现期下都存在节点溢流和管道过载情况,管道排水负荷偏高.

  3. Dynamic gauge adjustment of high-resolution X-band radar data for convective rain storms: Model-based evaluation against measured combined sewer overflow

    DEFF Research Database (Denmark)

    Borup, Morten; Grum, Morten; Linde, Jens Jørgen

    2016-01-01

    , well defined, 64 ha urban catchment, for nine overflow generating rain events. The dynamically adjusted radar data perform best when the aggregation period is as small as 10–20 min, in which case it performs much better than static adjusted radar data and data from rain gauges situated 2–3 km away.......Numerous studies have shown that radar rainfall estimates need to be adjusted against rain gauge measurements in order to be useful for hydrological modelling. In the current study we investigate if adjustment can improve radar rainfall estimates to the point where they can be used for modelling...... overflows from urban drainage systems, and we furthermore investigate the importance of the aggregation period of the adjustment scheme. This is done by continuously adjusting X-band radar data based on the previous 5–30 min of rain data recorded by multiple rain gauges and propagating the rainfall...

  4. 76 FR 53941 - Notice of Lodging of a Consent Decree Under the Clean Water Act

    Science.gov (United States)

    2011-08-30

    ... Euclid's operation of its municipal wastewater and sewer system. The Complaint alleges that the City discharges combined sewer overflows (``CSOs'') and sanitary sewer overflows (``SSOs'') in violation of...

  5. Dynamic gauge adjustment of high-resolution X-band radar data for convective rain storms: Model-based evaluation against measured combined sewer overflow

    Science.gov (United States)

    Borup, Morten; Grum, Morten; Linde, Jens Jørgen; Mikkelsen, Peter Steen

    2016-08-01

    Numerous studies have shown that radar rainfall estimates need to be adjusted against rain gauge measurements in order to be useful for hydrological modelling. In the current study we investigate if adjustment can improve radar rainfall estimates to the point where they can be used for modelling overflows from urban drainage systems, and we furthermore investigate the importance of the aggregation period of the adjustment scheme. This is done by continuously adjusting X-band radar data based on the previous 5-30 min of rain data recorded by multiple rain gauges and propagating the rainfall estimates through a hydraulic urban drainage model. The model is built entirely from physical data, without any calibration, to avoid bias towards any specific type of rainfall estimate. The performance is assessed by comparing measured and modelled water levels at a weir downstream of a highly impermeable, well defined, 64 ha urban catchment, for nine overflow generating rain events. The dynamically adjusted radar data perform best when the aggregation period is as small as 10-20 min, in which case it performs much better than static adjusted radar data and data from rain gauges situated 2-3 km away.

  6. Reducing CSOs and giving the river back to the public: innovative combined sewer overflow control and riverbanks restoration of the St. Charles River in Quebec City.

    Science.gov (United States)

    Fradet, Olivier; Pleau, Martin; Marcoux, Christiane

    2011-01-01

    After the construction of its wastewater treatment plants, the City of Quebec began to implement overflow control in wet weather to ultimately meet the effluent discharge objectives, i.e. no more than two overflows per summer season in the St. Lawrence River and no more than four in the St-Charles River. After several years of studies to determine which management strategies would best suit the purpose, and to propose optimum solutions, a first project to implement optimal and predictive management in real time, called "Pilot", came to life in 1999. Construction in phases soon followed and the work was completed in the fall of 2009. As a result, requirements with regard to environmental rejects were met in two sectors, namely the St-Charles River and the Jacques-Cartier Beach, and aquatic recreational activities could resume. Meanwhile, the City also worked at giving back access to the water courses to the public by developing sites at the Jacques-Cartier Beach and in the Bay of Beauport, and by rehabilitating the banks of the St-Charles River.

  7. Some Experiences with Numerical Modelling of Overflows

    DEFF Research Database (Denmark)

    Larsen, Torben; Nielsen, L.; Jensen, B.

    2007-01-01

    Overflows are commonly applied in storm sewer systems to control flow and water surface level. Therefore overflows play a central role in the control of discharges of pollutants from sewer systems to the environment. The basic hydrodynamic principle of an overflow is the so-called critical flow...... across the edge of the overflow. To ensure critical flow across the edge, the upstream flow must be subcritical whereas the downstream flow is either supercritical or a free jet. Experimentally overflows are well studied. Based on laboratory experiments and Froude number scaling, numerous accurate...... the term for curvature of the water surface (the so-called Boussinesq approximation) 2. 2- and 3-dimensional so-called Volume of Fluid Models (VOF-models) based on the full Navier-Stokes equations (named NS3 and developed by DHI Water & Environment) As a general conclusion, the two numerical models show...

  8. Mechanisms of fat, oil and grease (FOG) deposit formation in sewer lines.

    Science.gov (United States)

    He, Xia; de los Reyes, Francis L; Leming, Michael L; Dean, Lisa O; Lappi, Simon E; Ducoste, Joel J

    2013-09-01

    FOG deposits in sewer systems have recently been shown to be metallic salts of fatty acids. However, the fate and transport of FOG deposit reactant constituents and the complex interactions during the FOG deposit formation process are still largely unknown. In this study, batch tests were performed to elucidate the mechanisms of FOG deposit formation that lead to sanitary sewer overflows (SSOs). We report the first formation of FOG deposits on a concrete surface under laboratory conditions that mimic the formation of deposits in sewer systems. Results showed that calcium, the dominant metal in FOG deposits, can be released from concrete surfaces under low pH conditions and contribute to the formation process. Small amounts of additional oil to grease interceptor effluent substantially facilitated the air/water or pipe surface/water interfacial reaction between free fatty acids and calcium to produce surface FOG deposits. Tests of different fatty acids revealed that more viscous FOG deposit solids were formed on concrete surfaces, and concrete corrosion was accelerated, in the presence of unsaturated FFAs versus saturated FFAs. Based on all the data, a comprehensive model was proposed for the mechanisms of FOG deposit formation in sewer systems.

  9. Sewer Processes

    DEFF Research Database (Denmark)

    Hvitved-Jacobsen, Thorkild; Vollertsen, Jes; Nielsen, Asbjørn Haaning

    by hydrogen sulfide and other volatile organic compounds, as well as other potential health issues, have caused environmental concerns to rise. Reflecting the most current developments, Sewer Processes: Microbial and Chemical Process Engineering of Sewer Networks, Second Edition, offers the reader updated...... revisions of chapters from the previous edition, adds three new chapters, and presents extensive study questions. • Presents new modeling tools for the design and operation of sewer networks • Establishes sewer processes as a key element in preserving water quality • Includes greatly expanded coverage...... of odor formation and prediction • Details the WATS sewer process model • Highlights the importance of aerobic, anoxic, and anaerobic processes Sewer Processes: Microbial and Chemical Process Engineering of Sewer Networks, Second Edition, provides a basis for up-to-date understanding and modeling of sewer...

  10. Sewer Processes

    DEFF Research Database (Denmark)

    Hvitved-Jacobsen, Thorkild; Vollertsen, Jes; Nielsen, Asbjørn Haaning

    and valuable information on the sewer as a chemical and biological reactor. It focuses on how to predict critical impacts and control adverse effects. It also provides an integrated description of sewer processes in modeling terms. This second edition is full of illustrative examples and figures, includes...... microbial and chemical processes and demonstrates how this knowledge can be applied for the design, operation, and the maintenance of wastewater collection systems. The authors add chemical and microbial dimensions to the design and management of sewer networks with an overall aim of improved sustainability...... by hydrogen sulfide and other volatile organic compounds, as well as other potential health issues, have caused environmental concerns to rise. Reflecting the most current developments, Sewer Processes: Microbial and Chemical Process Engineering of Sewer Networks, Second Edition, offers the reader updated...

  11. Extreme Precipitation and Emergency Room Visits for Gastrointestinal Illness in Areas With and Without Combined Sewer Systems: An Analysis of Massachusetts Data, 2003-2007

    Science.gov (United States)

    Background: Combined sewer overflows (CSOs) occur in combined sewer systems when sewage and stormwater runoff discharge into waterbodies potentially contaminating water sources. CSOs are often caused by heavy precipitation and are expected to increase with increasing extreme pre...

  12. Extreme Precipitation and Emergency Room Visits for Gastrointestinal Illness in Areas With and Without Combined Sewer Systems: An Analysis of Massachusetts Data, 2003-2007

    Science.gov (United States)

    Background: Combined sewer overflows (CSOs) occur in combined sewer systems when sewage and stormwater runoff discharge into waterbodies potentially contaminating water sources. CSOs are often caused by heavy precipitation and are expected to increase with increasing extreme pre...

  13. On Hydraulic and Pollution Effects of Converting Combined Sewer Catchments to Separate Sewer Catchments

    DEFF Research Database (Denmark)

    Thorndahl, Søren Liedtke; Schaarup-Jensen, Kjeld; Rasmussen, Michael R.

    2015-01-01

    systems to become serviced with separate sewer systems decreases the volumes of storm water and pollutants diverted to the waste water treatment plant and discharged as combined sewer overflow. This happens at the expense of an increase in volumes of storm water and pollutant loads diverted to local...... receiving waters when detention ponds are not built-in the new separate sewer systems. It is concluded that consequences can be fatal for receiving waters, if no retention of pollutants is integrated into the system....

  14. The Effect of Converting Combined Sewer Catchments to Separate Sewer Catchments

    DEFF Research Database (Denmark)

    Schaarup-Jensen, Kjeld; Rasmussen, Michael R.; Thorndahl, Søren Liedtke

    2011-01-01

    The overall objective of this paper is to contribute to the standing debate concerning the advantages of separate sewer systems compared to traditional combined sewers. By a case study this investigation reveals that a transformation of one fourth of a given total area from being combined to become...... separate sewer catchments decreases the amounts of storm water and pollutants diverted to the waste water treatment plant (WWTP) or as combined sewer overflows (CSO). But this happens at the expense of an increase in amounts of storm water and pollutants diverted to local receiving waters when detention...... ponds are not built-in the new separate sewer systems. If a total catchment area transformation – instead of only one fourth – is put through, the consequences could be fatal for receiving waters if no retention of pollutants is integrated in such a transformation....

  15. The Effect of Converting Combined Sewer Catchments to Separate Sewer Catchments

    DEFF Research Database (Denmark)

    Schaarup-Jensen, Kjeld; Rasmussen, Michael R.; Thorndahl, Søren Liedtke

    2011-01-01

    The overall objective of this paper is to contribute to the standing debate concerning the advantages of separate sewer systems compared to traditional combined sewers. By a case study this investigation reveals that a transformation of one fourth of a given total area from being combined to become...... separate sewer catchments decreases the amounts of storm water and pollutants diverted to the waste water treatment plant (WWTP) or as combined sewer overflows (CSO). But this happens at the expense of an increase in amounts of storm water and pollutants diverted to local receiving waters when detention...... ponds are not built-in the new separate sewer systems. If a total catchment area transformation – instead of only one fourth – is put through, the consequences could be fatal for receiving waters if no retention of pollutants is integrated in such a transformation....

  16. Towards better management of combined sewer systems. A methodology based on low-cost monitoring

    OpenAIRE

    Montserrat Royuela, Albert

    2015-01-01

    In combined sewer systems (CSS) wastewater and stormwater flow through the same pipes. During severe rain episodes, the excess combined flow of untreated wastewater and stormwater is released out from the system through overflow structures, producing the combined sewer overflows (CSO). CSOs represent a threat for water quality of receiving water bodies and for human health, for what current (and future) legislation on the protection of water quality, are demanding more control on this transie...

  17. SEWER NETWORK DISCHARGE OPTIMIZATION USING THE DYNAMIC PROGRAMMING

    Directory of Open Access Journals (Sweden)

    Viorel MINZU

    2015-12-01

    Full Text Available It is necessary to adopt an optimal control that allows an efficient usage of the existing sewer networks, in order to avoid the building of new retention facilities. The main objective of the control action is to minimize the overflow volume of a sewer network. This paper proposes a method to apply a solution obtained by discrete dynamic programming through a realistic closed loop system.

  18. Catchment & sewer network simulation model to benchmark control strategies within urban wastewater systems

    DEFF Research Database (Denmark)

    Saagi, Ramesh; Flores Alsina, Xavier; Fu, Guangtao

    2016-01-01

    This paper aims at developing a benchmark simulation model to evaluate control strategies for the urban catchment and sewer network. Various modules describing wastewater generation in the catchment, its subsequent transport and storage in the sewer system are presented. Global/local overflow bas...

  19. Flood Grouting for Infiltration Reduction on Private Side Sewers (WERF Report INFR5R11)

    Science.gov (United States)

    The sewers in Seattle’s Broadview neighborhood, built in the 1950s, experience significant inflow and infiltration. Intense wet weather events have resulted in sewer overflows into private residences and the environment and previous work indicates that the majority of this excess...

  20. The Characteristics of Waste Water Flow in a Danish Combined Sewer

    DEFF Research Database (Denmark)

    Schaarup-Jensen, Kjeld; Rasmussen, Michael R.

    2004-01-01

    have been analysed in order to extract some of their characteristics. Furthermore it is emphasised that the presence of a self-cleansing capacity of a combined sewer system is of vital importance in order to reduce the impact of combined sewer overflows on receiving waters. Whether or not the pipelines...

  1. Flood Grouting for Infiltration Reduction on Private Side Sewers (WERF Report INFR5R11)

    Science.gov (United States)

    The sewers in Seattle’s Broadview neighborhood, built in the 1950s, experience significant inflow and infiltration. Intense wet weather events have resulted in sewer overflows into private residences and the environment and previous work indicates that the majority of this excess...

  2. An approach to pathogens flux simulation in a combined sewer system

    OpenAIRE

    Breil, P.; Petit, S.; Boukerb, A.; Namour, P.; McCarthy, D; Cournoyer, B

    2013-01-01

    International audience; Combined sewer systems convey organic matters and pathogens coming from human and animal faeces. They are mixed with rainfall runoff during storm event and can overflows to natural aquatic systems. Preliminary genetic analyses of pathogens were conducted in an experimental small water course and its lateral combined sewer system (OTHU site). Results indicate that natural system pathogens are an evolution of sewer system pathogens. However their presumed survival should...

  3. 76 FR 49505 - Notice of Lodging of a Consent Decree Under the Clean Water Act

    Science.gov (United States)

    2011-08-10

    ... sewage from its sanitary sewer system-- discharges that often are referred to as Sanitary Sewer Overflows or ``SSOs''--and from MSD's combined storm water and sanitary sewer system--discharges that often are referred to as Combined Sewer Overflows or ``CSOs''--violate MSD's National Pollutant Discharge...

  4. Self-optimising control of sewer systems

    DEFF Research Database (Denmark)

    Mauricio Iglesias, Miguel; Montero-Castro, I.; Mollerup, Ane Loft

    2013-01-01

    Self-optimising control is a useful concept to select optimal controlled variables from a set of candidate measurements in a systematic manner. In this study, use self-optimizing control tools and apply them to the specific features of sewer systems, e.g. the continuously transient dynamics......, the availability of a large number of measurements, the stochastic and unforeseeable character of the disturbances (rainfall). Using a subcatchment area in the Copenhagen sewer system as a case study we demonstrate, step by step, the formulation of the self-optimising control problem. The final result...... is an improved control structure aimed at optimizing the losses for a given control objective, here the minimization of the combined sewer overflows despite rainfall variations....

  5. Handling Overflow in MLton

    DEFF Research Database (Denmark)

    Hansen, Alexander Bjerremand; Midtgaard, Jan

    The definition of Standard ML dictates that overflow in integer arithmetic raises an overflow exception. As a consequence standard-conforming implementations of the language have to check for overflow which can be costly.We examine the possibility of further optimizing the code generated by the i...

  6. Handling Overflow in MLton

    DEFF Research Database (Denmark)

    Hansen, Alexander Bjerremand; Midtgaard, Jan

    The definition of Standard ML dictates that overflow in integer arithmetic raises an overflow exception. As a consequence standard-conforming implementations of the language have to check for overflow which can be costly.We examine the possibility of further optimizing the code generated by the i......The definition of Standard ML dictates that overflow in integer arithmetic raises an overflow exception. As a consequence standard-conforming implementations of the language have to check for overflow which can be costly.We examine the possibility of further optimizing the code generated...... prototype in Standard ML and integrated it into MLton as an additional optimization pass. It is able to remove 22% of the overflow checks in the MLton benchmark suite. The binary size of the programs decrease up to 10% and the run time of arithmetic heavy programs decrease significantly - in some cases up...

  7. Real Rainfall Time Series for Storm Sewer Design

    DEFF Research Database (Denmark)

    Larsen, Torben

    1981-01-01

    This paper describes a simulation method for the design of retention storages, overflows etc. in storm sewer systems. The method is based on computer simulation with real real rainfall time series as input and with a simple transfer model of the ARMA-type (Autoregressive moving average) applied...

  8. Real Rainfall Time Series for Storm Sewer Design

    DEFF Research Database (Denmark)

    Larsen, Torben

    The paper describes a simulation method for the design of retention storages, overflows etc. in storm sewer systems. The method is based on computer simulation with real rainfall time series as input ans with the aply of a simple transfer model of the ARMA-type (autoregressiv moving average model...

  9. Hydrocarbons and heavy metals in the different sewer deposits in the ‘Le Marais’ catchment (Paris, France): stocks, distributions and origins

    OpenAIRE

    Rocher, Vincent; Azimi, Sam; Moilleron, Régis; Chebbo, Ghassan

    2004-01-01

    International audience; The knowledge of the pollution stored in combined sewers is of prime importance in terms of management of wet weather flow pollution since sewer deposits play a significant role as source of pollution in combined sewer overflows. This work, which focused on the hydrocarbon (aliphatic and aromatic hydrocarbons) and metallic (Fe, Zn, Pb, Cu and Cd) pollution fixed to the different kinds of sewer deposits (gross bed sediment wGBSx, organic layer wOLx and biofilm), was per...

  10. Simulating groundwater-induced sewer flooding

    Science.gov (United States)

    Mijic, A.; Mansour, M.; Stanic, M.; Jackson, C. R.

    2016-12-01

    During the last decade, Chalk catchments of southern England experienced severe groundwater flooding. High groundwater levels resulted in the groundwater ingress into the sewer network that led to restricted toilet use and the overflow of diluted, but untreated sewage to road surfaces, rivers and water courses. In response to these events the water and sewerage company Thames Water Utilities Ltd (TWUL) had to allocate significant funds to mitigate the impacts. It was estimated that approximately £19m was spent responding to the extreme wet weather of 2013-14, along with the use of a fleet of over 100 tankers. However, the magnitude of the event was so large that these efforts could not stop the discharge of sewage to the environment. This work presents the analysis of the risk of groundwater-induced sewer flooding within the Chalk catchment of the River Lambourn, Berkshire. A spatially distributed groundwater model was used to assess historic groundwater flood risk and the potential impacts of changes in future climate. We then linked this model to an urban groundwater model to enable us to simulate groundwater-sewer interaction in detail. The modelling setup was used to identify relationships between infiltration into sewers and groundwater levels at specific points on TWUL's sewer network, and to estimate historic and future groundwater flood risk, and how this varies across the catchment. The study showed the significance of understanding the impact of groundwater on the urban water systems, and producing information that can inform a water company's response to groundwater flood risk, their decision making process and their asset management planning. However, the knowledge gained through integrated modelling of groundwater-sewer interactions has highlighted limitations of existing approaches for the simulation of these coupled systems. We conclude this work with number of recommendations about how to improve such hydrological/sewer analysis.

  11. REMOTELY CONTROLLED SEWERS

    OpenAIRE

    2014-01-01

    The basics of remotely controlled sewers [1] are presented focusing on Leipzig Municipality’s sewer control project [2] located in Germany. The consequences of sewer surcharge events are outlined considering possible counter measures. The required data basis, the controllable sewer objects and their relevant control units are pointed out. The presentation is finished exposing the types of control network, possible control algorithms as well as important aspects regarding the decision for / ag...

  12. Characterization of Washoff Behavior of In-Sewer Deposits in Combined Sewer Systems.

    Science.gov (United States)

    Kim, WeonJae; Furumai, Hiroaki

    2016-06-01

    In-sewer deposits in combined sewer systems (CSSs) are closely related with the behavior of first foul flush and combined sewer overflows. The artificial flushing experiment separating the washoff of in-sewer deposits from the inflow of surface pollutants was carried out to simulate first foul flush in a CSS. The washoff behaviors of each pollutant including chemical pollutants, bacterial indicators, and enteric viruses were intensively investigated. By using several morphological analyses, some of which were suggested through this study, the characteristics of first foul flush were examined. As a result, the washoff behaviors of each pollutant were characterized according to their (i) event load ratios (ELRs), (ii) time-series concentration and load curves, (iii) concentration vs. flow rate curves, and (iv) dimensionless runoff concentrations (DRCs). The first foul flush patterns of each parameter were categorized into 3 typical groups: the strong-, partial-, and no first foul flush group. The order of these groups signifies their different physicochemical properties of in-sewer deposits in CSSs, their strength of first foul flush phenomena, and the washoff priority as well.

  13. Use of online water quality monitoring for assessing the effects of WWTP overflows in rivers.

    Science.gov (United States)

    Boënne, Wesley; Desmet, Nele; Van Looy, Stijn; Seuntjens, Piet

    2014-05-01

    The effects on river water quality of sewer overflows are not well known. Since the duration of the overflow is in the order of magnitude of minutes to hours, continuous measurements of water quality are needed and traditional grab sampling is unable to quantify the pollution loads. The objective of this paper was to demonstrate the applicability of high frequency measurements for assessing the impacts of waste water treatment plants on the water quality of the receiving surface water. In our in situ water quality monitoring setup, two types of multiparameter sensors mounted on a floating fixed platform were used to determine the dynamics of dissolved oxygen, specific conductivity, ammonium-N, nitrate-N and dissolved organic carbon downstream of a waste water treatment plant (WWTP), in combination with data on rainfall, river discharge and WWTP overflow discharge. The monitoring data for water quantity and water quality were used to estimate the pollution load from waste water overflow events and to assess the impact of waste water overflows on the river water quality. The effect of sewer overflow on a small river in terms of N load was shown to be significant. The WWTP overflow events accounted for about 1/3 of the river discharge. The NH4-N loads during overflow events contributed 29% and 21% to the August 2010 and June 2011 load, respectively, in only 8% and 3% of the monthly time span. The results indicate that continuous monitoring is needed to accurately represent the effects of sewer overflows in river systems.

  14. Biodegradability of organic matter associated with sewer sediments during first flush.

    OpenAIRE

    Sakrabani, R.; Vollertsen, J.; Ashley, R.M.; Hvitved-Jacobsen, T.

    2009-01-01

    The high pollution load in wastewater at the beginning of a rain event is commonly known to originate from the erosion of sewer sediments due to the increased flow rate under storm weather conditions. It is essential to characterize the biodegradability of organic matter during a storm event in order to quantify the effect it can have further downstream to the receiving water via discharges from Combined Sewer Overflow (CSO). The approach is to characterize the pollutograph during first flush...

  15. Peracetic Acid as a Green Disinfectant for Combined Sewer Overflows

    Science.gov (United States)

    This cooperative research and development agreement between U.S. EPA, Solvay, MSDGC, and CB&I is evaluating the potential of PAA for disinfection of Muddy Creek CSO wastewater and comparing that with sodium hypochlorite disinfection. This presentation will document the effectiven...

  16. Molecular survey of concrete sewer biofilm microbial communities.

    Science.gov (United States)

    Santo Domingo, Jorge W; Revetta, Randy P; Iker, Brandon; Gomez-Alvarez, Vicente; Garcia, Jarissa; Sullivan, John; Weast, James

    2011-10-01

    The microbial composition of concrete biofilms within wastewater collection systems was studied using molecular assays. SSU rDNA clone libraries were generated from 16 concrete surfaces of manholes, a combined sewer overflow, and sections of a corroded sewer pipe. Of the 2457 sequences analyzed, α-, β-, γ-, and δ-Proteobacteria represented 15%, 22%, 11%, and 4% of the clones, respectively. β-Proteobacteria (47%) sequences were more abundant in the pipe crown than any of the other concrete surfaces. While 178 to 493 Operational Taxonomic Units (OTUs) were associated with the different concrete samples, only four sequences were shared among the different clone libraries. Bacteria implicated in concrete corrosion were found in the clone libraries while archaea, fungi, and several bacterial groups were also detected using group-specific assays. The results showed that concrete sewer biofilms are more diverse than previously reported. A more comprehensive molecular database will be needed to better study the dynamics of concrete biofilms.

  17. Assessing the Role of Sewers and Atmospheric Deposition as Nitrate Contamination Sources to Urban Surface Waters using Stable Nitrate Isotopes

    Science.gov (United States)

    Sikora, M. T.; Elliott, E. M.

    2009-12-01

    Excess nitrate (NO3-) contributes to the overall degraded quality of streams in many urban areas. These systems are often dominated by impervious surfaces and storm sewers that can route atmospherically deposited nitrogen, from both wet and dry deposition, to waterways. Moreover, in densely populated watersheds there is the potential for interaction between urban waterways and sewer systems. The affects of accumulated nitrate in riverine and estuary systems include low dissolved oxygen, loss of species diversity, increased mortality of aquatic species, and general eutrophication of the waterbody. However, the dynamics of nitrate pollution from each source and it’s affect on urban waterways is poorly constrained. The isotopes of nitrogen and oxygen in nitrate have been proven effective in helping to distinguish contamination sources to ground and surface waters. In order to improve our understanding of urban nitrate pollution sources and dynamics, we examined nitrate isotopes (δ15N and δ18O) in base- and stormflow samples collected over a two-year period from a restored urban stream in Pittsburgh, Pennsylvania (USA). Nine Mile Run drains a 1,600 hectare urban watershed characterized by 38% impervious surface cover. Prior work has documented high nitrate export from the watershed (~19 kg NO3- ha-1 yr-1). Potential nitrate sources to the watershed include observed sewer overflows draining directly to the stream, as well as atmospheric deposition (~23 kg NO3- ha-1 yr-1). In this and other urban systems with high percentages of impervious surfaces, there is likely minimal input from nitrate derived from soil or fertilizer. In this presentation, we examine spatial and temporal patterns in nitrate isotopic composition collected at five locations along Nine Mile Run characterized by both sanitary and combined-sewer cross-connections. Preliminary isotopic analysis of low-flow winter streamwater samples suggest nitrate export from Nine Mile Run is primarily influenced by

  18. Measuring Flow Reductions in a Combined Sewer System Using Green Infrastructure

    Science.gov (United States)

    A green infrastructure (GI) design approach was used in CSO Basin #130, a 17-acre sewershed in the Butchertown section of Louisville, Kentucky, to reduce combined sewer overflows (CSOs). For the design year, the modeled design was expected to reduce the CSO frequency from 34 to ...

  19. City sewer collectors biocorrosion

    Science.gov (United States)

    Ksiażek, Mariusz

    2014-12-01

    This paper presents the biocorrosion of city sewer collectors impregnated with special polymer sulphur binders, polymerized sulphur, which is applied as the industrial waste material. The city sewer collectors are settled with a colony of soil bacteria which have corrosive effects on its structure. Chemoautotrophic nitrifying bacteria utilize the residues of halites (carbamide) which migrate in the city sewer collectors, due to the damaged dampproofing of the roadway and produce nitrogen salts. Chemoorganotrophic bacteria utilize the traces of organic substrates and produce a number of organic acids (formic, acetic, propionic, citric, oxalic and other). The activity of microorganisms so enables the origination of primary and secondary salts which affect physical properties of concretes in city sewer collectors unfavourably.

  20. Air Conditioning Overflow Sensor

    Science.gov (United States)

    1996-01-01

    The Technology Transfer Office at Stennis Space Center helped a local inventor develop a prototype of an attachment for central air conditioners and heat pumps that helps monitor water levels to prevent condensation overflow. The sensor will indicate a need for drain line maintenance and prevent possible damage caused by drain pan water spillover. An engineer in the Stennis Space Center prototype Development Laboratory used SSC sensor technology in the development of the sensor.

  1. Air Conditioning Overflow Sensor

    Science.gov (United States)

    1996-01-01

    The Technology Transfer Office at Stennis Space Center helped a local inventor develop a prototype of an attachment for central air conditioners and heat pumps that helps monitor water levels to prevent condensation overflow. The sensor will indicate a need for drain line maintenance and prevent possible damage caused by drain pan water spillover. An engineer in the Stennis Space Center prototype Development Laboratory used SSC sensor technology in the development of the sensor.

  2. A generalised Dynamic Overflow Risk Assessment (DORA) for Real Time Control of urban drainage systems

    DEFF Research Database (Denmark)

    Vezzaro, Luca; Grum, Morten

    2014-01-01

    An innovative and generalised approach to the integrated Real Time Control of urban drainage systems is presented. The Dynamic Overflow Risk Assessment (DORA) strategy aims to minimise the expected Combined Sewer Overflow (CSO) risk by considering (i) the water volume presently stored in the drai......An innovative and generalised approach to the integrated Real Time Control of urban drainage systems is presented. The Dynamic Overflow Risk Assessment (DORA) strategy aims to minimise the expected Combined Sewer Overflow (CSO) risk by considering (i) the water volume presently stored...... in the drainage network, (ii) the expected runoff volume (calculated by radar-based nowcast models) and – most important – (iii) the estimated uncertainty of the runoff forecasts. The inclusion of uncertainty allows for a more confident use of Real Time Control (RTC). Overflow risk is calculated by a flexible...... periods, using a simple conceptual model, is presented. Compared to a traditional local control approach, DORA contributed to reduce CSO volumes from the most sensitive points while reducing total CSO volumes discharged from the catchment. Additionally, the results show that the inclusion of forecasts...

  3. Effects of climate and sewer condition on virus transport to groundwater

    Science.gov (United States)

    Pathogen contamination from leaky sanitary sewers poses a threat to groundwater quality in urban areas, yet the spatial and temporal dimensions of this contamination are not well understood. In this study, 16 monitoring wells and six municipal wells were repeatedly sampled for human enteric viruses....

  4. Sewer Lateral Electro Scan Field Verification Pilot (WERF Report INFR4R12)

    Science.gov (United States)

    Abstract:WERF selected a proposed research project to field test an emerging technology for inspecting sanitary sewer lateral pipes. The technology is called Electro Scan and is used to find defects in laterals that allow the infiltration of groundwater into the lateral. Electro ...

  5. USEPA CAPSTONE REPORT: CONTROL AND TREATMENT

    Science.gov (United States)

    Combined-sewer overflows (CSOs), sanitary-sewer overflows and stormwater (SW) are significant contributors of contamination to surface waters. During a rain event, the flow in a combined sewer system may exceed the capacity of the intercepting sewer leading to the wastewater trea...

  6. Narratives of Public Health in Dickens's Journalism: The Trouble with Sanitary Reform.

    Science.gov (United States)

    Smith, Ralph F

    2015-01-01

    Although Dickens is still known as having been a highly visible supporter of England's well-known nineteenth-century sanitary movement, he became, in fact, deeply troubled by many of this movement's fundamental tenets, as evidenced by journal narratives on fever that he edited and wrote in the mid-nineteenth century. Rather than water and sewer engineering works and a sanitary regime policed by government agencies as envisaged by Edwin Chadwick and other sanitary reformers, Dickens's view by 1855 was that only a massive erasure of the existing social and political systems and their replacement by an utterly new infrastructure would suffice.

  7. Quality of local control for simple sewer networks

    Science.gov (United States)

    Kolechkina, Alla; van Nooijen, Ronald

    2016-04-01

    Combined sewer networks, where both foul water and storm water are transported through the same system, tend to develop into complex networks due to expansion of towns and villages. The transport capacity of these systems is always limited, so occasional controlled spills into surface water, combined sewer overflows (CSO), are part of the normal operating procedure. Occasionally the ideas and rules present in the original design are not respected when the system is extended to cover a larger area. One way to deal with this problem is to implement central control. Another is to add pipes and hardware to bring the extended system into line with the original rules and ideas. We show that for a design rule often followed in the Netherlands, local control does quite well as long as the rule is respected and there are no large variations in precipitation intensity over the area covered by the system.

  8. A generic methodology for the optimisation of sewer systems using stochastic programming and self-optimizing control

    DEFF Research Database (Denmark)

    Maurico-Iglesias, Miguel; Castro, Ignacio Montero; Mollerup, Ane Loft

    2015-01-01

    The design of sewer system control is a complex task given the large size of the sewer networks, the transient dynamics of the water flow and the stochastic nature of rainfall. This contribution presents a generic methodology for the design of a self-optimising controller in sewer systems....... Such controller is aimed at keeping the system close to the optimal performance, thanks to an optimal selection of controlled variables. The definition of an optimal performance was carried out by a two-stage optimisation (stochastic and deterministic) to take into account both the overflow during the current...... rain event as well as the expected overflow given the probability of a future rain event. The methodology is successfully applied to design an optimising control strategy for a subcatchment area in Copenhagen. The results are promising and expected to contribute to the advance of the operation...

  9. Wastewater compounds in urban shallow groundwater wells correspond to exfiltration probabilities of nearby sewers.

    Science.gov (United States)

    Lee, Do Gyun; Roehrdanz, Patrick R; Feraud, Marina; Ervin, Jared; Anumol, Tarun; Jia, Ai; Park, Minkyu; Tamez, Carlos; Morelius, Erving W; Gardea-Torresdey, Jorge L; Izbicki, John; Means, Jay C; Snyder, Shane A; Holden, Patricia A

    2015-11-15

    Wastewater compounds are frequently detected in urban shallow groundwater. Sources include sewage or reclaimed wastewater, but origins are often unknown. In a prior study, wastewater compounds were quantified in waters sampled from shallow groundwater wells in a small coastal California city. Here, we resampled those wells and expanded sample analyses to include sewage- or reclaimed water-specific indicators, i.e. pharmaceutical and personal care product chemicals or disinfection byproducts. Also, we developed a geographic information system (GIS)-based model of sanitary sewer exfiltration probability--combining a published pipe failure model accounting for sewer pipe size, age, materials of construction, with interpolated depths to groundwater--to determine if sewer system attributes relate to wastewater compounds in urban shallow groundwater. Across the wells, groundwater samples contained varying wastewater compounds, including acesulfame, sucralose, bisphenol A, 4-tert-octylphenol, estrone and perfluorobutanesulfonic acid (PFBS). Fecal indicator bacterial concentrations and toxicological bioactivities were less than known benchmarks. However, the reclaimed water in this study was positive for all bioactivity tested. Excluding one well intruded by seawater, the similarity of groundwater to sewage, based on multiple indicators, increased with increasing sanitary sewer exfiltration probability (modeled from infrastructure within ca. 300 m of each well). In the absence of direct exfiltration or defect measurements, sewer exfiltration probabilities modeled from the collection system's physical data can indicate potential locations where urban shallow groundwater is contaminated by sewage.

  10. Statistically based sustainable re-design of stormwater overflow control systems in urban catchments

    Science.gov (United States)

    Ganora, Daniele; Isacco, Silvia; Claps, Pierluigi

    2017-04-01

    Control and reduction of pollution from stormwater overflow is a major concern for municipalities to manage the quality of the receiving water bodies according to the Framework Water Directive 2000/60/CE. In this regard, assessment studies of the potential pollution load from sewer networks recognize the need for adaptation and upgrade of existing drainage systems, which can be achieved with either traditional water works (detention tanks, increase of wastewater treatment plant capacity, etc.) or even Nature-based solutions (constructed wetlands, restored floodplains, etc.) sometimes used in combination. Nature-based solutions are recently receiving consistent attentions as they are able to enhance urban and degraded environments being, in the same time, more resilient and adaptable to climatic and anthropic changes than most traditional engineering works. On the other hand, restoration of the urban environment using natural absorbing surfaces requires diffuse interventions, high costs and a considerable amount of time. In this work we investigate how simple, economically-sustainable and quick solutions to the problem at hand can be addressed by changes in the management rules when pumping stations play a role in sewer systems. In particular, we provide a statistically-based framework to be used in the calibration of the management rules, facing improved quality of overflows from sewer systems. Typical pumping rules favor a massive delivery of stormwater volumes to the wastewater treatment plans, requiring large storage tanks in the sewer network, heavy pumping power and reducing the efficiency of the treatment plant due to pollutant dilution. In this study we show that it is possible to optimize the pumping rule in order to reduce pumped volumes to the plant (thus saving energy), while simultaneously keeping high pollutant concentration. On the other hand, larger low-concentration overflow volumes are released outside the sewer network with respect to the standard

  11. Probabilistic modelling of overflow, surcharge and flooding in urban drainage using the first-order reliability method and parameterization of local rain series

    DEFF Research Database (Denmark)

    Thorndahl, Søren; Willems, Patrick

    2007-01-01

    Failure of urban drainage systems may occur due to surcharge or flooding at specific manholes in the system, or due to overflows from combined sewer systems to receiving waters. To quantify the probability or return period of failure, standard approaches make use of the simulation of design storm...

  12. Design and Development of Vision Based Blockage Clearance Robot for Sewer Pipes

    Directory of Open Access Journals (Sweden)

    Krishna Prasad Nesaian

    2012-03-01

    Full Text Available Robotic technology is one of the advanced technologies, which is capable of completing tasks at situations where humans are unable to reach, see or survive. The underground sewer pipelines are the major tools for the transportation of effluent water. A lot of troubles caused by blockage in sewer pipe will lead to overflow of effluent water, sanitation problems. So robotic vehicle that is capable of traveling at underneath effluent water determining blockage using ultrasonic sensors and clearing by means of drilling mechanism is done. In addition to that wireless camera is fixed which acts as a robot vision by which we can monitor video and capture images using MATLAB tool. Thus in this project a prototype model of underground sewer pipe blockage clearance robot with drilling type will be developed

  13. A methodological approach to the design of optimising control strategies for sewer systems

    DEFF Research Database (Denmark)

    Mollerup, Ane Loft; Mikkelsen, Peter Steen; Sin, Gürkan

    2016-01-01

    This study focuses on designing an optimisation based control for sewer system in a methodological way and linking itto a regulatory control. Optimisation based design is found to depend on proper choice of a model, formulation of objective function and tuning of optimisation parameters. Accordin......This study focuses on designing an optimisation based control for sewer system in a methodological way and linking itto a regulatory control. Optimisation based design is found to depend on proper choice of a model, formulation of objective function and tuning of optimisation parameters...... control; a rule based expert system. On the other hand, compared with a regulatory control technique designed earlier in Mollerup et al. (2015), the optimisation showed similar performance with respect to minimising overflow volume. Hence for operation of small sewer systems, regulatory control strategies...... can offer promising potential and should be considered along more advanced strategies when identifying novel solutions....

  14. Changes in water quality parameters due to in-sewer processes.

    Science.gov (United States)

    Boxall, J; Shepherd, W; Guymer, I; Fox, K

    2003-01-01

    Combined sewer systems contain a large number of organic and inorganic pollutants from both domestic and industrial sources. These pollutants are often retained within the combined sewer system for significant lengths of time before entering sewage treatment works, or being spilt to a watercourse via a combined sewer overflow (CSO) during storm conditions. Currently little knowledge exists concerning the effects of in sewer processes on pollutants. Understanding of in-sewer processes is important for the effective and efficient design of treatment works and CSO chambers and for impact assessments on receiving waters. A series of studies covering storm and dry weather flow conditions were undertaken with the aim of investigating the nature of in-sewer processes. These studies consisted of marking a body of water with a fluorescent tracer. The tracer was then monitored at a series of downstream sites, and discrete samples collected from the body of water as it progressed through the sewer. The samples were analysed for water quality parameters and these results investigated in tandem with the detailed hydraulic information gained through the tracer studies. The results highlight the hydraulic differences between storm and dry weather conditions such as increased travel times and mixing under storm conditions. The Advection Dispersion Equation (ADE) and Aggregated Dead Zone (ADZ) model parameters have been quantified for the tracer data. The ADE mixing coefficient is shown to increase by an order of magnitude for storm conditions. The ADZ dispersive fraction parameter is shown to be approximately constant with flow. Chemical reactions and decay within the sewer system were found to be consistent with oxygen limitation.

  15. The distribution dynamics and desorption behaviour of mobile pharmaceuticals and caffeine to combined sewer sediments.

    Science.gov (United States)

    Hajj-Mohamad, M; Darwano, H; Duy, S Vo; Sauvé, S; Prévost, M; Arp, H P H; Dorner, S

    2017-01-01

    Pharmaceuticals are discharged to the environment from wastewater resource recovery facilities, sewer overflows, and illicit sewer connections. To understand the fate of pharmaceuticals, there is a need to better understand their sorption dynamics to suspended sediments (SS) and settled sediments (StS) in sewer systems. In this study, such sorption dynamics to both SS and StS were assessed using a batch equilibrium method under both static and dynamic conditions. Experiments were performed with natively occurring and artificially modified concentrations of sewer pharmaceuticals (acetaminophen, theophylline, carbamazepine, and a metabolite of carbamazepine) and caffeine. Differences in apparent distribution coefficients, Kd,app, between SS and StS were related to differences in their organic carbon (OC) content, and the practice of artificially modifying the concentration. Kd,app values of modified contaminant concentrations and high OC sediments were substantially higher. Pseudo-second order desorption rates for these mobile compounds were also quantified. Successive flushing events to simulate the addition of stormwater to sewer networks revealed that aqueous concentrations would not necessarily decrease, because the added water will rapidly return to equilibrium concentrations with the sediments. Sorption and desorption kinetics must be considered in addition to dilution, to avoid underestimating the influence of dilution on concentrations of pharmaceuticals discharged to the environment.

  16. The myth of phenomenological overflow.

    Science.gov (United States)

    Brown, Richard

    2012-06-01

    In this paper I examine the dispute between Hakwan Lau, Ned Block, and David Rosenthal over the extent to which empirical results can help us decide between first-order and higher-order theories of consciousness. What emerges from this is an overall argument to the best explanation against the first-order view of consciousness and the dispelling of the mythological notion of phenomenological overflow that comes with it. Copyright © 2011 Elsevier Inc. All rights reserved.

  17. Sewer Gas: An Indoor Air Source of PCE to Consider During Vapor Intrusion Investigations.

    Science.gov (United States)

    Pennell, Kelly G; Scammell, Madeleine Kangsen; McClean, Michael D; Ames, Jennifer; Weldon, Brittany; Friguglietti, Leigh; Suuberg, Eric M; Shen, Rui; Indeglia, Paul A; Heiger-Bernays, Wendy J

    2013-01-01

    The United States Environmental Protection Agency (USEPA) is finalizing its vapor intrusion guidelines. One of the important issues related to vapor intrusion is background concentrations of volatile organic chemicals (VOCs) in indoor air, typically attributed to consumer products and building materials. Background concentrations can exist even in the absence of vapor intrusion and are an important consideration when conducting site assessments. In addition, the development of accurate conceptual models that depict pathways for vapor entry into buildings is important during vapor intrusion site assessments. Sewer gas, either as a contributor to background concentrations or as part of the site conceptual model, is not routinely evaluated during vapor intrusion site assessments. The research described herein identifies an instance where vapors emanating directly from a sanitary sewer pipe within a residence were determined to be a source of tetrachloroethylene (PCE) detected in indoor air. Concentrations of PCE in the bathroom range from 2.1 to 190 ug/m(3) and exceed typical indoor air concentrations by orders of magnitude resulting in human health risk classified as an "Imminent Hazard" condition. The results suggest that infiltration of sewer gas resulted in PCE concentrations in indoor air that were nearly two-orders of magnitude higher as compared to when infiltration of sewer gas was not known to be occurring. This previously understudied pathway whereby sewers serve as sources of PCE (and potentially other VOC) vapors is highlighted. Implications for vapor intrusion investigations are also discussed.

  18. Real-time control of sewer systems using turbidity measurements.

    Science.gov (United States)

    Lacour, C; Schütze, M

    2011-01-01

    Real-time control (RTC) of urban drainage systems has been proven useful as a means to reduce pollution by combined sewer overflow discharges. So far, RTC has been investigated mainly with a sole focus on water quantity aspects. However, as measurement techniques for pollution of wastewater are advancing, pollution-based RTC might be of increasing interest. For example, turbidity data sets from an extensive measurement programme in two Paris catchments allow a detailed investigation of the benefits of using pollution-based data for RTC. This paper exemplifies this, comparing pollution-based RTC with flow-based RTC. Results suggest that pollution-based RTC indeed has some potential, particularly when measurements of water-quality characteristics are readily available.

  19. A model for methane production in sewers.

    Science.gov (United States)

    Chaosakul, Thitirat; Koottatep, Thammarat; Polprasert, Chongrak

    2014-09-19

    Most sewers in developing countries are combined sewers which receive stormwater and effluent from septic tanks or cesspools of households and buildings. Although the wastewater strength in these sewers is usually lower than those in developed countries, due to improper construction and maintenance, the hydraulic retention time (HRT) could be relatively long and resulting considerable greenhouse gas (GHG) production. This study proposed an empirical model to predict the quantity of methane production in gravity-flow sewers based on relevant parameters such as surface area to volume ratio (A/V) of sewer, hydraulic retention time (HRT) and wastewater temperature. The model was developed from field survey data of gravity-flow sewers located in a peri-urban area, central Thailand and validated with field data of a sewer system of the Gold Coast area, Queensland, Australia. Application of this model to improve construction and maintenance of gravity-flow sewers to minimize GHG production and reduce global warming is presented.

  20. Self-optimising control of sewer systems

    DEFF Research Database (Denmark)

    Mauricio Iglesias, Miguel; Montero-Castro, Ignacio; Mollerup, Ane Loft;

    The design of sewer system control is a complex task given the large size of the sewer networks, the transient dynamics of the water flows and the stochastic nature of rainfall. This contribution presents a generic methodology for the design of a self-optimising controller in sewer systems...... to design an optimising control strategy for a subcathcment area in Copenhagen....

  1. Sanitary costs of osteoarthritis

    Directory of Open Access Journals (Sweden)

    M. Franceschini

    2011-09-01

    Full Text Available Muscoloskeletal disorders are the first cause of disability and the second cause of permanent disablement in Italy. Osteoarthritis is the most frequent rheumatic disease and affects about 4 million Italians. In spite of that, data concerning social costs are lacking. On account of this lack we measured sanitary costs of 314 patients suffering from osteoarthritis. A retrospective, prevalence- based multicentric study was performed using a bottom-up approach. The study period was 12 months and referred to 1999. Eight percent of patients didn’t take any drug for the treatment of osteoarthritis; NSAIDs were prescribed to 86.9% of patients, analgesics to 29.9%, chondroprotective drugs to 7.6%, and gastroprotective drugs to 36.9%. Total sanitary costs came to 455 € / patient / year: 122 € were spent on diagnostics, 293 € on therapy and 40 € on management of drug-related gastropathy. Since the costs of anti-inflammatory drugs came to 30 € we calculated iatrogenic cost factor of 2.3. Moreover, the study supplied interesting informations about prescriptive habits, which differ in Italy from international guidelines for the medical treatment of OA, about patient management, because of hospitalization, which by itself absorbs 1/3 of resources, and about physiotherapy, which costs twice as much as pharmacological therapy. At last, data analysis gave the cue for suggestions on changing patients’ management.

  2. Planning solutions of sanitary facilities in modern residential buildings

    Directory of Open Access Journals (Sweden)

    Orlov Evgeniy Vladimirovich

    2015-01-01

    Full Text Available In the article the short historical review on the design of sanitary rooms and their configurations is given. The main errors of the recent years, which led to the decrease in accommodation convenience because of the wrong approach from both the architect and engineers, are given. It is possible to use a small useful area for sanitary facilities, but it is connected with the lack of possibility of connecting washing and dishwashers. The author considers the options of engineering equipment placement in sanitary rooms taking into account the convenience of use, safety, and also resource-saving aspect. Various solutions on the organization of heating and ventilation are provided. The possible technical solutions allowing solving a flooding problem of the first floors in elite housing estates in case of accident are offered with the help of full waterproofing of sanitary rooms, and also the whole area of the apartment. The main attention was focused on the improvements of sanitary rooms for one-room and two-room apartments, which are the most demanded in the modern market of real estate. Layout solutions of the reduced bathrooms on the placement of the necessary equipment with choice justification are provided. The attention is paid to the layout solution for modern kitchens on order to increase their comfort by the use of special two-section sinks, and also a grinder of food waste in order to allow to lower the load of the systems of rubbish disposal of a building, by dumping the crushed garbage in an internal sewer network. Various options of evolutionary development of sanitary rooms for increasing the comfort degree are given. First of all, the development should happen in the direction of not only sanitation and hygiene, but also of the maintenance of the physical health of the people living in the building. It can be carried out by increase in a useful area of sanitary rooms, installation of exercise machines, medical bathtubs and a Jacuzzi

  3. Fat, oil and grease deposits in sewers: characterisation of deposits and formation mechanisms.

    Science.gov (United States)

    Williams, J B; Clarkson, C; Mant, C; Drinkwater, A; May, E

    2012-12-01

    Fat, oil and grease deposits (FOG) in sewers are a major problem and can cause sewer overflows, resulting in environmental damage and health risks. Often simplistically portrayed as cooling of fats, recent research has suggested that saponification may be involved in FOG formation. However there are still questions about the mechanisms effecting transformations in sewers and the role and source of metal cations involved in saponification. This study characterises FOG deposits from pumping stations, sewers and sewage works from different water hardness zones across the UK. The sites all had previous problems with FOG and most catchments contained catering and food preparation establishments. The FOG deposits were highly variable with moisture content ranging from 15 to 95% and oil content from 0 to 548 mg/g. Generally the pumping stations had lower moisture content and higher fat content, followed by the sewers then the sewage works. The water in contact with the FOG had high levels of oil (mean of about 800 mg/L) and this may indicate poor kitchen FOG management practices. FOG fatty acid profiles showed a transformation from unsaturated to saturated forms compared to typical cooking oils. This seems to relate to ageing in the sewer network or the mechanism of formation, as samples from pumping stations had higher proportions of C18:1 compared to C16. This may be due to microbial transformations by bacteria such as Clostridium sp. in a similar process to adipocere formation. There was an association between water hardness and increased Ca levels in FOG along with harder deposits and higher melting points. A link between FOG properties and water hardness has not been previously reported for field samples. This may also be due to microbial processes, such as biocalcification. By developing the understanding of these mechanisms it may be possible to more effectively control FOG deposits, especially when combined with promotion of behavioural change.

  4. Temporal asymmetry in precipitation time series and its influence on flow simulations in combined sewer systems

    Science.gov (United States)

    Müller, Thomas; Schütze, Manfred; Bárdossy, András

    2017-09-01

    A property of natural processes is temporal irreversibility. However, this property cannot be reflected by most statistics used to describe precipitation time series and, consequently, is not considered in most precipitation models. In this paper, a new statistic, the asymmetry measure, is introduced and applied to precipitation enabling to detect and quantify irreversibility. It is used to analyze two different data sets of Singapore and Germany. The data of both locations show a significant asymmetry for high temporal resolutions. The asymmetry is more pronounced for Singapore where the climate is dominated by convective precipitation events. The impact of irreversibility on applications is analyzed on two different hydrological sewer system models. The results show that the effect of the irreversibility can lead to biases in combined sewer overflow statistics. This bias is in the same order as the effect that can be achieved by real time control of sewer systems. Consequently, wrong conclusion can be drawn if synthetic time series are used for sewer systems if asymmetry is present, but not considered in precipitation modeling.

  5. Research of trace metals as markers of entry pathways in combined sewers.

    Science.gov (United States)

    Gounou, C; Varrault, G; Amedzro, K; Gasperi, J; Moilleron, R; Garnaud, S; Chebbo, G

    2011-01-01

    Combined sewers receive high toxic trace metal loads emitted by various sources, such as traffic, industry, urban heating and building materials. During heavy rain events, Combined Sewer Overflows (CSO) can occur and, if so, are discharged directly into the aquatic system and therefore could have an acute impact on receiving waters. In this study, the concentrations of 18 metals have been measured in 89 samples drawn from the three pollutant Entry Pathways in Combined Sewers (EPCS): i) roof runoff, ii) street runoff, and iii) industrial and domestic effluents and also drawn from sewer deposits (SD). The aim of this research is to identify metallic markers for each EPCS; the data matrix was submitted to principal component analysis in order to determine metallic markers for the three EPCS and SD. This study highlights the fact that metallic content variability across samples from different EPCS and SD exceeds the spatio-temporal variability of samples from the same EPCS. In the catchment studied here, the most valuable EPCS and SD markers are lead, sodium, boron, antimony and zinc; these markers could be used in future studies to identify the contributions of each EPCS to CSO metallic loads.

  6. Storm water management in an urban catchment: effects of source control and real-time management of sewer systems on receiving water quality.

    Science.gov (United States)

    Frehmann, T; Nafo, I; Niemann, A; Geiger, W F

    2002-01-01

    For the examination of the effects of different storm water management strategies in an urban catchment area on receiving water quality, an integrated simulation of the sewer system, wastewater treatment plant and receiving water is carried out. In the sewer system real-time control measures are implemented. As examples of source control measures the reduction of wastewater and the reduction of the amount of impervious surfaces producing storm water discharges are examined. The surface runoff calculation and the simulation of the sewer system and the WWTP are based on a MATLAB/SIMULINK simulation environment. The impact of the measures on the receiving water is simulated using AQUASIM. It can be shown that the examined storm water management measures, especially the source control measures, can reduce the combined sewer overflow volume and the pollutant discharge load considerably. All examined measures also have positive effects on the receiving water quality. Moreover, the reduction of impervious surfaces avoids combined sewer overflow activities, and in consequence prevents pollutants from discharging into the receiving water after small rainfall events. However, the receiving water quality improvement may not be seen as important enough to avoid acute receiving water effects in general.

  7. Spatial Models of Sewer Pipe Leakage Predict the Occurrence of Wastewater Indicators in Shallow Urban Groundwater.

    Science.gov (United States)

    Roehrdanz, Patrick R; Feraud, Marina; Lee, Do Gyun; Means, Jay C; Snyder, Shane A; Holden, Patricia A

    2017-02-07

    Twentieth century municipal wastewater infrastructure greatly improved U.S. urban public health and water quality. However, sewer pipes deteriorate, and their accumulated structural defects may release untreated wastewater to the environment via acute breaks or insidious exfiltration. Exfiltrated wastewater constitutes a loss of potentially reusable water and delivers a complex and variable mix of contaminants to urban shallow groundwater. Yet, predicting where deteriorated sewers impinge on shallow groundwater has been challenging. Here we develop and test a spatially explicit model of exfiltration probability based on pipe attributes and groundwater elevation without prior knowledge of exfiltrating defect locations. We find that models of exfiltration probability can predict the probable occurrence in underlying shallow groundwater of established wastewater indicators including the artificial sweetener acesulfame, tryptophan-like fluorescent dissolved organic matter, nitrate, and a stable isotope of water (δ(18)O). The strength of the association between exfiltration probability and indicators of wastewater increased when multiple pipe attributes, distance weighting, and groundwater flow direction were considered in the model. The results prove that available sanitary sewer databases and groundwater digital elevation data can be analyzed to predict where pipes are likely leaking and contaminating groundwater. Such understanding could direct sewer infrastructure reinvestment toward water resource protection.

  8. Cesium and strontium loads into a combined sewer system from rainwater runoff.

    Science.gov (United States)

    Kamei-Ishikawa, Nao; Yoshida, Daiki; Ito, Ayumi; Umita, Teruyuki

    2016-12-01

    In this study, combined sewage samples were taken with time in several rain events and sanitary sewage samples were taken with time in dry weather to calculate Cs and Sr loads to sewers from rainwater runoff. Cs and Sr in rainwater were present as particulate forms at first flush and the particulate Cs and Sr were mainly bound with inorganic suspended solids such as clay minerals in combined sewage samples. In addition, multiple linear regression analysis showed Cs and Sr loads from rainwater runoff could be estimated by the total amount of rainfall and antecedent dry weather days. The variation of the Sr load from rainwater to sewers was more sensitive to total amount of rainfall and antecedent dry weather days than that of the Cs load.

  9. A generalised Dynamic Overflow Risk Assessment (DORA) for Real Time Control of urban drainage systems

    Science.gov (United States)

    Vezzaro, Luca; Grum, Morten

    2014-07-01

    An innovative and generalised approach to the integrated Real Time Control of urban drainage systems is presented. The Dynamic Overflow Risk Assessment (DORA) strategy aims to minimise the expected Combined Sewer Overflow (CSO) risk by considering (i) the water volume presently stored in the drainage network, (ii) the expected runoff volume (calculated by radar-based nowcast models) and - most important - (iii) the estimated uncertainty of the runoff forecasts. The inclusion of uncertainty allows for a more confident use of Real Time Control (RTC). Overflow risk is calculated by a flexible function which allows for the prioritisation of the discharge points according to their sensitivity and intended use. DORA was tested on a hypothetical example inspired by the main catchment in the city of Aarhus (Denmark). An analysis of DORA’s performance over a range of events with different return periods, using a simple conceptual model, is presented. Compared to a traditional local control approach, DORA contributed to reduce CSO volumes from the most sensitive points while reducing total CSO volumes discharged from the catchment. Additionally, the results show that the inclusion of forecasts and their uncertainty contributed to further improving the performance of drainage systems. The results of this paper will contribute to the wider usage of global RTC methods in the management of urban drainage networks.

  10. APPROACH TO "FURTHER-REASONABLE-PROGRESS" TO ATTAIN WATER QUALITY STANDARDS

    Science.gov (United States)

    Watershed managers in urban areas in the US are pursuing optimum strategies or plans for managing wastewater treatment plants, stormwater systems, sanitary sewer overflows (SSO) and combined sewer overflows (CSO). Often these strategies are based on an iterative process or a "fur...

  11. Corrosion and odor management in sewer systems.

    Science.gov (United States)

    Jiang, Guangming; Sun, Jing; Sharma, Keshab R; Yuan, Zhiguo

    2015-06-01

    Sewers emit hydrogen sulfide and various volatile organic sulfur and carbon compounds, which require control and mitigation. In the last 5-10 years, extensive research was conducted to optimize existing sulfide abatement technologies based on newly developed in-depth understanding of the in-sewer processes. Recent advances have also led to low-cost novel solutions targeting sewer biofilms. Online control has been demonstrated to greatly reduce the chemical usage. Dynamic models for both the water, air and solid (concrete) phases have been developed and used for the planning and maintenance of sewer systems. Existing technologies primarily focused on 'hotspots' in sewers. Future research should aim to achieve network-wide corrosion and emission control and management of sewers as an integrated component of an urban water system.

  12. Green-blue water in the city: quantification of impact of source control versus end-of-pipe solutions on sewer and river floods.

    Science.gov (United States)

    De Vleeschauwer, K; Weustenraad, J; Nolf, C; Wolfs, V; De Meulder, B; Shannon, K; Willems, P

    2014-01-01

    Urbanization and climate change trends put strong pressures on urban water systems. Temporal variations in rainfall, runoff and water availability increase, and need to be compensated for by innovative adaptation strategies. One of these is stormwater retention and infiltration in open and/or green spaces in the city (blue-green water integration). This study evaluated the efficiency of three adaptation strategies for the city of Turnhout in Belgium, namely source control as a result of blue-green water integration, retention basins located downstream of the stormwater sewers, and end-of-pipe solutions based on river flood control reservoirs. The efficiency of these options is quantified by the reduction in sewer and river flood frequencies and volumes, and sewer overflow volumes. This is done by means of long-term simulations (100-year rainfall simulations) using an integrated conceptual sewer-river model calibrated to full hydrodynamic sewer and river models. Results show that combining open, green zones in the city with stormwater retention and infiltration for only 1% of the total city runoff area would lead to a 30 to 50% reduction in sewer flood volumes for return periods in the range 10-100 years. This is due to the additional surface storage and infiltration and consequent reduction in urban runoff. However, the impact of this source control option on downstream river floods is limited. Stormwater retention downstream of the sewer system gives a strong reduction in peak discharges to the receiving river. However due to the difference in response time between the sewer and river systems, this does not lead to a strong reduction in river flood frequency. The paper shows the importance of improving the interface between urban design and water management, and between sewer and river flood management.

  13. INVESTIGATION AND EVALUATION OF CRYPTOSPORIDIUM AND GIARDIA IN COMBINED SEWER OVERFLOW (CSO) AND STORMWATER RUNOFF

    Science.gov (United States)

    Since the first identified Cryptosporidium outbreaks occurred in the 1980s and the massive 1993 Milwaukee, WI outbreak affected more than 400,000 people, the concern over the public health risks related to protozoan pathogens Cryptosporidium and Giardia has g...

  14. Coordinated management of combined sewer overflows by means of advanced environmental decision support systems

    DEFF Research Database (Denmark)

    Murla, Damian; Gutierrez, Oriol; Martinez, Montse

    2016-01-01

    Highlights •A decision support system was developed for CSO minimization during wet weather. •The acquired expert knowledge was implemented in a set of 21 decision trees. •The operational intercomparison illustrated better results for the EDSS mode. •The expert quality evaluation exposed environm......Highlights •A decision support system was developed for CSO minimization during wet weather. •The acquired expert knowledge was implemented in a set of 21 decision trees. •The operational intercomparison illustrated better results for the EDSS mode. •The expert quality evaluation exposed...

  15. Application of Green Infrastructure for Combined Sewer Overflow, Kansas City, MO

    Science.gov (United States)

    The U.S. Environmental Protection Agency (EPA) encourages communities to adopt environmentally friendly design practices and other “green” management techniques when addressing stormwater control and management. Advanced design concepts such as Low Impact Development (LID) and Gr...

  16. ENVIRONMENTAL RESEARCH BRIEF: STORAGE/SEDIMENTATION FACILITIES FOR CONTROL OF STORM AND COMBINED SEWER OVERFLOWS

    Science.gov (United States)

    This report describes applications of storage facilities in wet-weather flow (WWF) control and presents step-by-step procedures for the analysis and design of storage-treatment facilities. Retention, detention, and sedimentation storage are classified and described. International...

  17. Comparing Peracetic Acid with Sodium Hypochlorite for Disinfection of Combined Sewer Overflows

    Science.gov (United States)

    This cooperative research and development agreement between U.S. EPA, Solvay, MSDGC, and CB&I is evaluating the potential of PAA for disinfection of Muddy Creek CSO wastewater and comparing that with sodium hypochlorite disinfection. This presentation will document the effective...

  18. Quantifying fat, oil, and grease deposit formation kinetics

    Science.gov (United States)

    Fat, oil, and grease (FOG) deposits formed in sanitary sewers are calcium-based saponified solids that are responsible for a significant number of nationwide sanitary sewer overflows (SSOs) across United States. In the current study, the kinetics of lab-based saponified solids were determined to un...

  19. The Sewer Research Station in Frejlev

    DEFF Research Database (Denmark)

    Schaarup-Jensen, Kjeld; Hvitved-Jacobsen, T.

    This report for the 2000 activities at the sewer research station in Frejlev. Only few - if any - sewer monitoring stations like the one in Frejlev exist. Without no doubt the field data produced - especially the time series - in the course of time will serve as a unique basis for projects dealing...

  20. A Novel Model for Sewer Ventilation

    DEFF Research Database (Denmark)

    Fuglsang, Emil Dietz; Nielsen, Asbjørn Haaning; Vollertsen, Jes

    2013-01-01

    Based on the naturally occurring gas CO2 the dynamics of natural ventilation and gas flow was studied in an intercepting sewer receiving wastewater from a pressure main. A deterministic physiochemical model including description of release of CO2 into the sewer gas phase was built and validated a...... against field measurements....

  1. Information use in Dutch sewer assest management

    NARCIS (Netherlands)

    Van Riel, W.A.P.; Langeveld, J.G.; Herder, P.M.; Clemens, F.H.L.R.

    2012-01-01

    Sewer systems are capital-intensive infrastructures, requiring appropriate asset management to safeguard serviceability. In the Netherlands, effective sewer asset management is described by De Leeuw’s control paradigm. Reliable data and information are key elements in decision-making for rehabilitat

  2. The Sewer Research Station in Frejlev

    DEFF Research Database (Denmark)

    Hvitved-Jacobsen, Thorkild; Schaarup-Jensen, Kjeld

    2003-01-01

    This report for the 1999 activities at the sewer research station in Frejlev. Only few - if any - sewer monitoring stations like the one in Frejlev exist. Without no doubt the field data produced - especially the time series - in the course of time will serve as a unigue basis for projects dealing...

  3. In-place rehabilitation of process sewers

    Energy Technology Data Exchange (ETDEWEB)

    Arles, K.R.; Faller, C.C. [E.I. DuPont de Nemours and Co., Inc., Wilmington, DE (United States)

    1996-07-01

    The majority of petrochemical manufacturing facilities have thousands of feet of existing underground gravity sewers that convey the site`s industrial wastes to treatment facilities. The integrity of these sewer systems is a serious concern to owners. A potential consequence of leaks is soil and groundwater contamination. Prior to 1992, only two options were available to remedy this situation. The sewer systems could be replaced with either a new dual-walled, monitored underground pipe system via direct bury, or with an above ground pumped system. In 1992, Engineering, in conjunction with several trenchless technology vendors, developed and demonstrated modified relining systems that can rehabilitate existing sewers and result in monitored dual-walled gravity sewer systems. These proven systems have since been enhanced, upgraded, and installed at two operating facilities. With thorough sewer investigation and assessments, industry now has viable, cost effective options to rehabilitate underground chemical process sewers. These upgraded sewer systems provide the environmental security of monitored dual-walled pipe, enhanced flow characteristics, and retain accessibility for maintenance and inspections.

  4. [Topical problems of sanitary and epidemiologic examination concerning projects of sanitary protection zones in airports].

    Science.gov (United States)

    Isayeva, A M; Zibaryov, E V

    2015-01-01

    The article covers data on major errors in sanitary protection zones specification for civil airports, revealed through sanitary epidemiologic examination. The authors focus attention on necessity to develop unified methodic approach to evaluation of aviation noise effects, when justifying sanitary protection zone of airports and examining sanitary and epidemiologic project documents.

  5. Ventilation in Sewers Quantified by Measurements of CO2

    DEFF Research Database (Denmark)

    Fuglsang, Emil Dietz; Vollertsen, Jes; Nielsen, Asbjørn Haaning

    2012-01-01

    H, alkalinity and sewer-air CO2 concentrations. An intercepting sewer was studied and an average sewer-air retention time of approximately 1.5-2.5 hours was found at CO2 levels around 4-6 times the natural background. Also an upstream sub-catchment was studied. In this part of the sewer system the level of CO2...

  6. [Numerical simulation of TP transport after overflow of rainwater into urban lake].

    Science.gov (United States)

    Gong, Chun-Sheng; Mao, Xian-Zhong; Zhang, Xi-Hui

    2009-04-15

    Based on the three-dimensional advection-diffusion-reflection equation, a two-dimensional TP transport equation was deduced to simulate TP distribution and transport after overflow rainwater into urban lake from storm sewer system during rainstorm. The model has a good agreement with a group of monitor data at Lake Lichee in Shenzhen, China. The model was applied to compute the scenario in Lake Lichee under the design rainstorm, and analyse the fate of TP. It shows that TP flux into lake is 15.385 kg under city storm intensity of 28 mm/h, in which 62.3% of flux goes into water in lake and 28.1% TP flux settles surface sediment. It would take 3.0 days for the integrated treatment project operation to recover TP to the level before the rain.

  7. Buffer Overflow Detection on Binary Code

    Institute of Scientific and Technical Information of China (English)

    ZHENG Yan-fei; LI Hui; CHEN Ke-fei

    2006-01-01

    Most solutions for detecting buffer overflow are based on source code. But the requirement for source code is not always practical especially for business software. A new approach was presented to detect statically the potential buffer overflow vulnerabilities in the binary code of software. The binary code was translated into assembly code without the lose of the information of string operation functions. The feature code abstract graph was constructed to generate more accurate constraint statements, and analyze the assembly code using the method of integer range constraint. After getting the elementary report on suspicious code where buffer overflows possibly happen, the control flow sensitive analysis using program dependence graph was done to decrease the rate of false positive. A prototype was implemented which demonstrates the feasibility and efficiency of the new approach.

  8. Sulfide and methane production in sewer sediments.

    Science.gov (United States)

    Liu, Yiwen; Ni, Bing-Jie; Ganigué, Ramon; Werner, Ursula; Sharma, Keshab R; Yuan, Zhiguo

    2015-03-01

    Recent studies have demonstrated significant sulfide and methane production by sewer biofilms, particularly in rising mains. Sewer sediments in gravity sewers are also biologically active; however, their contribution to biological transformations in sewers is poorly understood at present. In this study, sediments collected from a gravity sewer were cultivated in a laboratory reactor fed with real wastewater for more than one year to obtain intact sediments. Batch test results show significant sulfide production with an average rate of 9.20 ± 0.39 g S/m(2)·d from the sediments, which is significantly higher than the areal rate of sewer biofilms. In contrast, the average methane production rate is 1.56 ± 0.14 g CH4/m(2)·d at 20 °C, which is comparable to the areal rate of sewer biofilms. These results clearly show that the contributions of sewer sediments to sulfide and methane production cannot be ignored when evaluating sewer emissions. Microsensor and pore water measurements of sulfide, sulfate and methane in the sediments, microbial profiling along the depth of the sediments and mathematical modelling reveal that sulfide production takes place near the sediment surface due to the limited penetration of sulfate. In comparison, methane production occurs in a much deeper zone below the surface likely due to the better penetration of soluble organic carbon. Modelling results illustrate the dependency of sulfide and methane productions on the bulk sulfate and soluble organic carbon concentrations can be well described with half-order kinetics.

  9. Management of storm water in unitary sewer systems; Gestion de las aguas de tormenta en las redes de alcantarillado unitarias

    Energy Technology Data Exchange (ETDEWEB)

    Rayos, C.

    1999-08-01

    A brief review is provided of the general problems of storm waters and how they are dealt with in Directive 91/27/EEC. An experiment in Asturias, Spain, is reported in which storm water storage tanks were designed to reduce the number and impact of discharges from the unitary sewer systems. The criteria for calculating the design flows in accordance with the guidelines of Spain`s Northern Hydrographic Confederation, the procedures used in determining the size of the overflows and the different elements employed in the equipment, control systems and safety systems are all described. (Author) 31 refs.

  10. Time series modelling of overflow structures

    DEFF Research Database (Denmark)

    Carstensen, J.; Harremoës, P.

    1997-01-01

    to the overflow structures. The capacity of a pump draining the storage pipe has been estimated for two rain events, revealing that the pump was malfunctioning during the first rain event. The grey-box modelling approach is applicable for automated on-line surveillance and control. (C) 1997 IAWQ. Published......The dynamics of a storage pipe is examined using a grey-box model based on on-line measured data. The grey-box modelling approach uses a combination of physically-based and empirical terms in the model formulation. The model provides an on-line state estimate of the overflows, pumping capacities...

  11. Model Predictive Control of Sewer Networks

    Science.gov (United States)

    Pedersen, Einar B.; Herbertsson, Hannes R.; Niemann, Henrik; Poulsen, Niels K.; Falk, Anne K. V.

    2017-01-01

    The developments in solutions for management of urban drainage are of vital importance, as the amount of sewer water from urban areas continues to increase due to the increase of the world’s population and the change in the climate conditions. How a sewer network is structured, monitored and controlled have thus become essential factors for effcient performance of waste water treatment plants. This paper examines methods for simplified modelling and controlling a sewer network. A practical approach to the problem is used by analysing simplified design model, which is based on the Barcelona benchmark model. Due to the inherent constraints the applied approach is based on Model Predictive Control.

  12. Model Predictive Control of Sewer Networks

    DEFF Research Database (Denmark)

    Pedersen, Einar B.; Herbertsson, Hannes R.; Niemann, Henrik;

    2016-01-01

    The developments in solutions for management of urban drainage are of vital importance, as the amount of sewer water from urban areas continues to increase due to the increase of the world’s population and the change in the climate conditions. How a sewer network is structured, monitored...... and controlled have thus become essential factors for efficient performance of waste water treatment plants. This paper examines methods for simplified modelling and controlling a sewer network. A practical approach to the problem is used by analysing simplified design model, which is based on the Barcelona...

  13. OPTIMAL OPERATIONAL CONTROL OF INTERCEPTOR SEWER SYSTEM

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In this paper, a mathematical model was built up to solve the problem of optimal operational control by analysing the factors on an interceptor sewer system and a Fortran program was produced for this model. This paper shows that the optimal control states can be determined by working out the optimal flow rates by means of Linear Programming (LP). The result is very sensitive to interception points and the concentration weight coefficients over time. The result further highlights some practical applications for the existing sewer systems or the sewer systems under design.

  14. Following a drop of water from the cloud, throughout the sewer system, into the receiving water - Model predictive control of integrated sewer-wastewater treatment systems

    DEFF Research Database (Denmark)

    Mikkelsen, Peter Steen; Vezzaro, Luca; Sharma, Anitha Kumari

    of pollutants discharged from treatment plants, etc.). The tools developed in the SWI project include (but are not limited to (i) rainfall nowcasting based on radar measurements, (ii) probabilistic flow forecasting based on data assimilation and stochastic models, (iii) prediction and optimization of wet...... measurements, flow and water levels, operational parameters at treatment plants) it is possible to dynamically optimize the integrated storm- and wastewater systems according to different criteria (e.g. utilizing the system fully at all times and reducing volumes of combined sewer overflows, loads......-weather performance of wastewater treatment plants, and (iv) integrated control of the different elements of the integrated wastewater systems. Full-scale testing of these tools in different catchment located in Denmark ensure that the developed tools can represent an important step forwards for on-line operation...

  15. Numerical 3-D Modelling of Overflows

    DEFF Research Database (Denmark)

    Larsen, Torben; Nielsen, L.; Jensen, B.;

    2008-01-01

    The present study uses laboratory experiments to evaluate the reliability of two types of numerical models of sewers systems: - 1-dimensional model based on the extended Saint-Venant equation including the term for curvature of the water surface (the so-called Boussinesq approximation) - 2- and 3...

  16. 300 Area process sewer piping upgrade and 300 Area treated effluent disposal facility discharge to the City of Richland Sewage System, Hanford Site, Richland, Washington

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-05-01

    The U.S. Department of Energy (DOE) is proposing to upgrade the existing 300 Area Process Sewer System by constructing and operating a new process sewer collection system that would discharge to the 300 Area Treated Effluent Disposal Facility. The DOE is also considering the construction of a tie-line from the TEDF to the 300 Area Sanitary Sewer for discharging the process wastewater to the City of Richland Sewage System. The proposed action is needed because the integrity of the old piping in the existing 300 Area Process Sewer System is questionable and effluents might be entering the soil column from leaking pipes. In addition, the DOE has identified a need to reduce anticipated operating costs at the new TEDF. The 300 Area Process Sewer Piping Upgrade (Project L-070) is estimated to cost approximately $9.9 million. The proposed work would involve the construction and operation of a new process sewer collection system. The new system would discharge the effluents to a collection sump and lift station for the TEDF. The TEDF is designed to treat and discharge the process effluent to the Columbia River. The process waste liquid effluent is currently well below the DOE requirements for radiological secondary containment and is not considered a RCRA hazardous waste or a State of Washington Hazardous Waste Management Act dangerous waste. A National Pollutant Discharge Elimination, System (NPDES) permit has been obtained from the U.S. Environmental Protection Agency for discharge to the Columbia River. The proposed action would upgrade the existing 300 Area Process Sewer System by the construction and operation of a new combined gravity, vacuum, and pressurized process sewer collection system consisting of vacuum collection sumps, pressure pump stations, and buried polyvinyl chloride or similar pipe. Two buildings would also be built to house a main collection station and a satellite collection station.

  17. Optimization of Overflow Policies in Call Centers

    DEFF Research Database (Denmark)

    Koole, G.M.; Nielsen, B.F.; Nielsen, T.B.

    2015-01-01

    We examine how overflow policies in a multi-skill call center should be designed to accommodate performance measures that depend on waiting time percentiles such as service level. This is done using a discrete Markovian approximation of the waiting time of the first customers waiting in line...... and customers are treated in a FCFS order....

  18. Analysis and Study of Buffer Overflow

    Institute of Scientific and Technical Information of China (English)

    Liu Sidong; Zen TaoYu; Yongquan

    2009-01-01

    Buffer overflow attack is one of the most threatening attack types and it jeopardizes security a lot. According to the principle of the attack, this paper demonstrates how it works, and emphasizes the importance of writing code that does not permit such attacks.

  19. Comparison of Suspended Solid Separation in Advanced Storm Overflow Structures

    DEFF Research Database (Denmark)

    Larsen, Torben; Sørensen, Morten Steen

    1990-01-01

    This paper describes a laboratory investigation of the separation of suspended solids in a circular weir overflow and a vortex separator. The basic idea is to evaluate the efficiency of a vortical flow in the overflow chamber, and to compare these results with other overflow structures....

  20. Stream restoration and sewers impact sources and fluxes of water, carbon, and nutrients in urban watersheds

    Science.gov (United States)

    Pennino, Michael J.; Kaushal, Sujay S.; Mayer, Paul M.; Utz, Ryan M.; Cooper, Curtis A.

    2016-08-01

    An improved understanding of sources and timing of water, carbon, and nutrient fluxes associated with urban infrastructure and stream restoration is critical for guiding effective watershed management globally. We investigated how sources, fluxes, and flowpaths of water, carbon (C), nitrogen (N), and phosphorus (P) shift in response to differences in urban stream restoration and sewer infrastructure. We compared an urban restored stream with two urban degraded streams draining varying levels of urban development and one stream with upland stormwater management systems over a 3-year period. We found that there was significantly decreased peak discharge in response to precipitation events following stream restoration. Similarly, we found that the restored stream showed significantly lower (p exported most carbon, nitrogen, and phosphorus at relatively lower streamflow than the two more urban catchments, which exported most carbon and nutrients at higher streamflow. Annual exports of total carbon (6.6 ± 0.5 kg ha-1 yr-1), total nitrogen (4.5 ± 0.3 kg ha-1 yr-1), and total phosphorus (161 ± 15 kg ha-1 yr-1) were significantly lower in the restored stream compared to both urban degraded streams (p exports. However, nitrate isotope data suggested that 55 ± 1 % of the nitrate in the urban restored stream was derived from leaky sanitary sewers (during baseflow), statistically similar to the urban degraded streams. These isotopic results as well as additional tracers, including fluoride (added to drinking water) and iodide (contained in dietary salt), suggested that groundwater contamination was a major source of urban nutrient fluxes, which has been less considered compared to upland sources. Overall, leaking sewer pipes are a problem globally and our results suggest that combining stream restoration with restoration of aging sewer pipes can be critical to more effectively minimizing urban nonpoint nutrient sources. The sources, fluxes, and flowpaths of groundwater

  1. Environmental Assessment: Replace Sanitary Sewer from Building 801 to Lagoons at Grand Forks AFB, North Dakota

    Science.gov (United States)

    2010-09-01

    for Grand Forks AFB include Marsh Milkweed , Bottlebrush Sedge, Prairie Cordgrass, Wooly Sedge, Awl- Fruit Sedge, Baltic Rush, Wool-Grass, Soft-stem...AFB has a humid continental climate that is characterized by frequent and drastic weather changes. The summers are short and humid with frequent...Vegetation is robust at GFAFB wetlands and many are characterized as typical prairie potholes found within the northern plains ecoregion. Wetlands

  2. Predicting concrete corrosion of sewers using artificial neural network.

    Science.gov (United States)

    Jiang, Guangming; Keller, Jurg; Bond, Philip L; Yuan, Zhiguo

    2016-04-01

    Corrosion is often a major failure mechanism for concrete sewers and under such circumstances the sewer service life is largely determined by the progression of microbially induced concrete corrosion. The modelling of sewer processes has become possible due to the improved understanding of in-sewer transformation. Recent systematic studies about the correlation between the corrosion processes and sewer environment factors should be utilized to improve the prediction capability of service life by sewer models. This paper presents an artificial neural network (ANN)-based approach for modelling the concrete corrosion processes in sewers. The approach included predicting the time for the corrosion to initiate and then predicting the corrosion rate after the initiation period. The ANN model was trained and validated with long-term (4.5 years) corrosion data obtained in laboratory corrosion chambers, and further verified with field measurements in real sewers across Australia. The trained model estimated the corrosion initiation time and corrosion rates very close to those measured in Australian sewers. The ANN model performed better than a multiple regression model also developed on the same dataset. Additionally, the ANN model can serve as a prediction framework for sewer service life, which can be progressively improved and expanded by including corrosion rates measured in different sewer conditions. Furthermore, the proposed methodology holds promise to facilitate the construction of analytical models associated with corrosion processes of concrete sewers.

  3. Analysis and integrated modelling of groundwater infiltration to sewer networks

    DEFF Research Database (Denmark)

    Thorndahl, Søren Liedtke; Balling, Jonas Dueholm; Larsen, Uffe Bay Bøgh

    2016-01-01

    Infiltration of groundwater to sewer systems is a problem for the capacity of the system as well as for treatment processes at waste water treatment plants. This paper quantifies the infiltration of groundwater to a sewer system in Frederikshavn Municipality, Denmark, by measurements of sewer flow...... and novel model set-up, which simulates the interaction between groundwater and sewer flow. The study area has a separate waste water sewer system, but the discharged volumes from the system are approximately twice the volumes from a tight system without infiltration. The model set-up makes use of two...

  4. Rapidly solidified titanium alloys by melt overflow

    Science.gov (United States)

    Gaspar, Thomas A.; Bruce, Thomas J., Jr.; Hackman, Lloyd E.; Brasmer, Susan E.; Dantzig, Jonathan A.; Baeslack, William A., III

    1989-01-01

    A pilot plant scale furnace was designed and constructed for casting titanium alloy strips. The furnace combines plasma arc skull melting techniques with melt overflow rapid solidification technology. A mathematical model of the melting and casting process was developed. The furnace cast strip of a suitable length and width for use with honeycomb structures. Titanium alloys Ti-6Al-4V and Ti-14Al-21 Nb were successfully cast into strips. The strips were evaluated by optical metallography, microhardness measurements, chemical analysis, and cold rolling.

  5. Value of Information for Sewer Replacement Decisions

    NARCIS (Netherlands)

    Van Riel, W.A.P.; Langeveld, J.G.; Herder, P.M.; Clemens, F.H.L.R.

    2014-01-01

    Decision-making for sewer asset management is partially based on intuition and often lacks explicit argumentation, hampering decision transparency and reproducibility. It is unknown to what extent each information source is appreciated by decision makers. Further insight into this relative

  6. Water Hammer in Pumped Sewer Mains

    DEFF Research Database (Denmark)

    Larsen, Torben

    This publication is intended for engineers seeking an introduction to the problem of water hammer in pumped pressure mains. This is a subject of increasing interest because of the development of larger and more integrated sewer systems. Consideration of water hammer is essential for structural...

  7. Agile Design of Sewer System Control

    NARCIS (Netherlands)

    Van Nooijen, R.P.; Kolechkina, A.G.; Van Leeuwen, P.E.R.M.; Van Velzen, E.

    2011-01-01

    We describe the first part of an attempt to include stakeholder participation in the design of a central automatic controller for a sewer system in a small pilot project (five subcatchments) and present lessons learned so far. The pilot is part of a project aimed at the improvement of water quality

  8. A Sediment Transport Model for Sewers

    DEFF Research Database (Denmark)

    Mark, Ole; Larsson, Johan; Larsen, Torben

    1993-01-01

    This paper describes a mathematical model for transport processes in sewers. The model consists of three sub models, a surface model for the description of the buildup and the washoff of sediment particles from the surface area, a morphological model and an advection-dispersion model. The model...

  9. Effects Of Leaky Sewers On Groundwater Quality

    Science.gov (United States)

    Leschik, S.; Musolff, A.; Reinstorf, F.; Strauch, G.; Oswald, S. E.; Schirmer, M.

    2007-12-01

    The impact of urban areas on groundwater quality has become an emerging research field in hydrogeology. Urban subsurface infrastructures like sewer networks are often leaky, so untreated wastewater may enter the urban aquifer. The transport of wastewater into the groundwater is still not well understood under field conditions. In the research platform WASSER Leipzig (Water And Sewershed Study of Environmental Risk in Leipzig- Germany) the effects of leaky sewers on the groundwater quality are investigated. The research is focused on the occurrence and transport of so-called "xenobiotics" such as pharmaceuticals and personal care product additives. Xenobiotics may pose a threat on human health, but can also be considered a marker for an urban impact on water resources. A new test site was established in Leipzig to quantify mass fluxes of xenobiotics into the groundwater from a leaky sewer. Corresponding to the leaks which were detected by closed circuit television inspections, monitoring wells were installed up- and downstream of the sewer. Concentrations of eight xenobiotics (technical-nonylphenol, bisphenol-a, caffeine, galaxolide, tonalide, carbamazepine, phenazone, ethinylestradiol) obtained from first sampling programmes were found to be highly heterogeneous, but a relation between the position of the sampling points and the sewer could not be clearly identified. However, concentrations of sodium, chloride, potassium and nitrate increased significantly downstream of the sewer which may be due to wastewater exfiltration, since no other source is known on the water flowpath from the upstream to the downstream wells. Because of the highly heterogeneous spatial distribution of xenobiotics at the test site, a monitoring concept was developed comprising both high-resolution sampling and an integral approach to obtain representative average concentrations. Direct-push techniques were used to gain insight into the fine-scale spatial distribution of the target compounds

  10. Modelling the impact of soakaway retrofits on combined sewage overflows in a 3km2 urban catchment in Copenhagen, Denmark

    DEFF Research Database (Denmark)

    Roldin, Maria Kerstin; Fryd, Ole; Jeppesen, Jan;

    2012-01-01

    -step approach that employed GIS analyses and physically distributed, dynamic pipe flow modelling in an iterative manner, this study estimates the impact of infiltration on combined sewage overflows (CSOs) in a 3km2 urban catchment in Copenhagen. The first step was the creation of a baseline scenario. The second...... a more realistic scenario where only 8% of the impervious area was connected to soakaways and the reduction in CSO volume was 24%. The potential and realistic scenarios were modelled both with hydraulic coupling between soakaway and sewer, and as fully disconnected. Results show that infiltration...... is constrained mainly by the quality of the stormwater runoff from roads and limited land availability in the potential infiltration scenario, and by low-permeable soils and a problematically high groundwater level in the realistic infiltration scenario. The hydraulically coupled model gives higher CSO volume...

  11. Sanitary survey rapport 2: Nissum Bredning

    DEFF Research Database (Denmark)

    Larsen, Martin Mørk; Jakobsen, Hans Henrik; Göke, Cordula

    .3and the associated sampling plan are required to be based on so-called ‘sanitary surveys’. A sanitary survey is an assessment of the interactions between potential sources of microbial pollution, climate conditions and oceanography in the area. The EU Commission guidance for making a sanitary...... survey formed the basis for this report. However, in certain cases, the Danish practice for microbiological sampling frequency and classification made previously on the basis of this, as described in ‘muslingebekendtgørelsen’ is summarized in Appendix 13. The report covers production areas P1, P2, P3...... is determined in samples of mussels, etc. taken at different sampling points within each area. The report points to the most precautionary fixed sampling points for future monitoring In summary, the sanitary survey of Nissum Broads identifies an area that in general is a microbial homogeneous, stable...

  12. Systems with selective overflow and change of bandwidth

    DEFF Research Database (Denmark)

    Iversen, Villy Bæk

    2012-01-01

    on the overflow group, we show by balance equations that the number of calls of each service will be Multinomial distributed with probabilities proportional with the arrival rates. Using a recent result of Newcomer & al, we then find moments (done up to fourth order) of individual overflow streams or any...

  13. Climate impacts of parameterized Nordic Sea overflows

    Science.gov (United States)

    Danabasoglu, Gokhan; Large, William G.; Briegleb, Bruce P.

    2010-11-01

    A new overflow parameterization (OFP) of density-driven flows through ocean ridges via narrow, unresolved channels has been developed and implemented in the ocean component of the Community Climate System Model version 4. It represents exchanges from the Nordic Seas and the Antarctic shelves, associated entrainment, and subsequent injection of overflow product waters into the abyssal basins. We investigate the effects of the parameterized Denmark Strait (DS) and Faroe Bank Channel (FBC) overflows on the ocean circulation, showing their impacts on the Atlantic Meridional Overturning Circulation and the North Atlantic climate. The OFP is based on the Marginal Sea Boundary Condition scheme of Price and Yang (1998), but there are significant differences that are described in detail. Two uncoupled (ocean-only) and two fully coupled simulations are analyzed. Each pair consists of one case with the OFP and a control case without this parameterization. In both uncoupled and coupled experiments, the parameterized DS and FBC source volume transports are within the range of observed estimates. The entrainment volume transports remain lower than observational estimates, leading to lower than observed product volume transports. Due to low entrainment, the product and source water properties are too similar. The DS and FBC overflow temperature and salinity properties are in better agreement with observations in the uncoupled case than in the coupled simulation, likely reflecting surface flux differences. The most significant impact of the OFP is the improved North Atlantic Deep Water penetration depth, leading to a much better comparison with the observational data and significantly reducing the chronic, shallow penetration depth bias in level coordinate models. This improvement is due to the deeper penetration of the southward flowing Deep Western Boundary Current. In comparison with control experiments without the OFP, the abyssal ventilation rates increase in the North

  14. Overflow Concentration and Sedimentation in Hoppers

    DEFF Research Database (Denmark)

    Hjelmager Jensen, Jacob; Saremi, Sina

    2014-01-01

    at the inflow. The hopper constitutes a complex system despite its geometrical regularity; the complexities are largely from the settling processes in concentrated polydisperse mixtures. These settling processes can, however, be captured by employing available settling formulas applicable for multifractional...... stages can be captured using a sediment budget approach, i.e., by using continuity equations for water and sediment phases. In this study, the compositional transformation and the bed height inside the hopper are obtained by solving these equations, considering monodisperse, bidisperse, and polydisperse...... mixtures, the former analytically. Although assumptions tied to the mathematical model are fulfilled best for hoppers rigged with a multiple-inflow system, the model accurately predicts measured concentrations in the final stage of overflow for single-inflow systems. The model can be used...

  15. Integrated planning of rehabilitation strategies for sewers.

    Science.gov (United States)

    Kleidorfer, Manfred; Möderl, Michael; Tscheikner-Gratl, Franz; Hammerer, Max; Kinzel, Heiko; Rauch, Wolfgang

    2013-01-01

    Building measures in sewer systems are increasingly driven by rehabilitation/retrofitting and adaptation needs. Aging infrastructure together with changing boundary conditions (due to climate change, land-use change, demographic change) and also changing design standards and legislation require a prospective design to preserve the functionality of urban drainage systems not only today, but also in a long-term perspective. To improve a prospective design of urban water infrastructure, the Austrian Research Promotion Agency funded the research project 'REHAB - Integrated planning of rehabilitation strategies of urban infrastructure systems'. Therein a novel strategic planning tool which considers these external drivers of rehabilitation strategies is developed. In this study the scope of the project is described and, as well as first results regarding sewer pipe conditions, future development and vulnerability assessment are also discussed.

  16. Water Hammer in Pumped Sewer Mains

    DEFF Research Database (Denmark)

    Larsen, Torben

    This publication is intended for students and engineers seeking an introduction to the problem of water transients in pumped sewer and water mains. This is a subject of increasing interest because of the development of larger and more integrated systems. Consideration of transients is essential...... for the structural design of pipelines and for the planning of the proper function of the systems. The text is written by Torben Larsen, who is a professor of environmental hydraulics at the Department of Civil Engineering, Aalborg University. Torben Larsen has many years of experience with computer simulations...... of transients in pumped pipeline systems. This present publication can be understood as the second and revised edition of the pamphlet ”Transients in pumped sewer mains” (2006) which was published as a technical report by The EVA committee under The Danish Water Pollution Committee (The Danish Society...

  17. Treatment of Sewer Water Using Alum Salt

    OpenAIRE

    Qaid M. Saleem; Yousif Mohamed Algamal; Majed H. Shtaiwi; Mohammad S. Aldahmashi

    2014-01-01

    This investigation was carried out to study the effect of addition of different concentrations of alum salt used in the treatment of sewer water of the pond and also to study the physico-chemical parameters such as pH ,electrical conductivity ,salinity and total sediments besides that the bacteriological analysis such as total viable count (TVC) or standard plate count (SPC) and total coliform count (MPN) content were analysed in the water sample collected from the pond estimation of viable...

  18. The Historical Development of Sewers Worldwide

    Directory of Open Access Journals (Sweden)

    Giovanni De Feo

    2014-06-01

    Full Text Available Although there is evidence of surface-based storm drainage systems in early Babylonian and Mesopotamian Empires in Iraq (ca. 4000–2500 BC, it is not until after ca. 3000 BC that we find evidence of the well organized and operated sewer and drainage systems of the Minoans and Harappans in Crete and the Indus valley, respectively. The Minoans and Indus valley civilizations originally, and the Hellenes and Romans thereafter, are considered pioneers in developing basic sewerage and drainage technologies, with emphasis on sanitation in the urban environment. The Hellenes and Romans further developed these techniques and greatly increased the scale of these systems. Although other ancient civilizations also contributed, notably some of the Chinese dynasties, very little progress was made during the Dark ages from ca. 300 AD through to the middle of the 18th century. It was only from 1850 onwards that that modern sewerage was “reborn”, but many of the principles grasped by the ancients are still in use today. This paper traces the development of the sewer from those earliest of civilizations through to the present day and beyond. A 6000 year technological history is a powerful validation of the vital contribution of sewers to human history.

  19. Satellite Sanitary Systems in Kampala, Uganda

    NARCIS (Netherlands)

    Letema, S.; Van Vliet, B.; Van Lier, J.B.

    2011-01-01

    Satellite sewage collection and treatment systems have been independently developed and managed in East African cities outside the centrally planned and sewered areas. A satellite approach is a promising provisioning option parallel to public sewerage for middle- and high-income residential areas, e

  20. Satellite Sanitary Systems in Kampala, Uganda

    NARCIS (Netherlands)

    Letema, S.C.; Vliet, van B.J.M.; Lier, van J.B.

    2012-01-01

    Satellite sewage collection and treatment systems have been independently developed and managed in East African cities outside the centrally planned and sewered areas. A satellite approach is a promising provisioning option parallel to public sewerage for middle- and high-income residential areas, e

  1. The effect of motor overflow on bimanual asymmetric force coordination.

    Science.gov (United States)

    Cunningham, David A; Roelle, Sarah M; Allexandre, Didier; Potter-Baker, Kelsey A; Sankarasubramanian, Vishwanath; Knutson, Jayme S; Yue, Guang H; Machado, Andre G; Plow, Ela B

    2017-01-16

    Motor overflow, typically described in the context of unimanual movements, refers to the natural tendency for a 'resting' limb to move during movement of the opposite limb and is thought to be influenced by inter-hemispheric interactions and intra-cortical networks within the 'resting' hemisphere. It is currently unknown, however, how motor overflow contributes to asymmetric force coordination task accuracy, referred to as bimanual interference, as there is need to generate unequal forces and corticospinal output for each limb. Here, we assessed motor overflow via motor evoked potentials (MEPs) and the regulation of motor overflow via inter-hemispheric inhibition (IHI) and short-intra-cortical inhibition (SICI) using transcranial magnetic stimulation in the presence of unimanual and bimanual isometric force production. All outcomes were measured in the left first dorsal interosseous (test hand) muscle, which maintained 30% maximal voluntary contraction (MVC), while the right hand (conditioning hand) was maintained at rest, 10, 30, or 70% of its MVC. We have found that as higher forces are generated with the conditioning hand, MEP amplitudes at the active test hand decreased and inter-hemispheric inhibition increased, suggesting reduced motor overflow in the presence of bimanual asymmetric forces. Furthermore, we found that subjects with less motor overflow (i.e., reduced MEP amplitudes in the test hemisphere) demonstrated poorer accuracy in maintaining 30% MVC across all conditions. These findings suggest that motor overflow may serve as an adaptive substrate to support bimanual asymmetric force coordination.

  2. New Findings in Hydrogen Sulfide Related Corrosion of Concrete Sewers

    DEFF Research Database (Denmark)

    Nielsen, Asbjørn Haaning; Jensen, Henriette Stokbro; Hvitved-Jacobsen, Thorkild

    2009-01-01

    This paper summarizes major findings of a long-term study of hydrogen sulfide gas (H2S) adsorption and oxidation on concrete and plastic sewer pipe surfaces. The processes have been studied using a pilot-scale setup designed to replicate conditions in a gravity sewer located downstream of a force...... H2S concentration in concrete sewers would typically amount to a few percent of the equilibrium concentration calculated from Henrys law. In plastic pipe sewers, significantly higher concentrations were predicted because of the slower adsorption and oxidation kinetics on these surfaces. Finally...

  3. OVERFLOW DAMS ON SMOLL CHANNELS OF IRRIGATION SYSTEMS

    Directory of Open Access Journals (Sweden)

    Sainov Mihail Petrovich

    2013-04-01

    Full Text Available The article has data on potential designs of overflow structures made of soil rather than concrete. The most reliable and cheap ones are dykes made of sandbags. This viewpoint is substantiated by the operation of peatland irrigation systems, constructed in the Moscow region in 2011 — 2012. The construction of overflow sandbag dykes must have slope/riverbed protection structures to withstand their erosion by open and filtration flows of the downstream. Designs of overflow dykes having their downstream sides protected by geosynthetic coats, which are patented by other hydraulic engineers, have proven unreliable.

  4. Report: EPA Needs to Track Whether Its Major Municipal Settlements for Combined Sewer Overflows Benefit Water Quality

    Science.gov (United States)

    Report #15-P-0280, September 16, 2015. By tracking environmental results, the EPA can show how the $32 billion that communities are spending to address discharges of untreated sewage and contaminated storm water improves water quality.

  5. Felsenthal and Overflow National Wildlife Refuges: Comprehensive Conservation Plan

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This Comprehensive Conservation Plan (CCP) was written to guide management on Overflow and Felsenthal NWRs for the next 15 years. This plan outlines the refuges'...

  6. Single electron based binary multipliers with overflow detection

    African Journals Online (AJOL)

    ATHARVA

    Multipliers with overflow detection based on serial and parallel ... current following through a tunnel junction is a series of events in which only one electron ..... Processing delay based on SED and analyzed SED for parallel prefix circuit.

  7. A stable Faroe Bank Channel overflow 1995-2015

    Science.gov (United States)

    Hansen, Bogi; Húsgarð, Margretha; Larsen, Karin; Hátún, Hjálmar; Østerhus, Svein

    2016-11-01

    The Faroe Bank Channel (FBC) is the deepest passage across the Greenland-Scotland Ridge (GSR) and there is a continuous deep flow of cold and dense water passing through it from the Arctic Mediterranean into the North Atlantic and further to the rest of the world ocean. This FBC overflow is part of the Atlantic Meridional Overturning Circulation (AMOC), which has recently been suggested to have weakened. From November 1995 to May 2015, the FBC overflow has been monitored by a continuous ADCP (acoustic Doppler current profiler) mooring, which has been deployed in the middle of this narrow channel. Combined with regular hydrography cruises and several short-term mooring experiments, this allowed us to construct time series of volume transport and to follow changes in the hydrographic properties and density of the FBC overflow. The mean kinematic overflow, derived solely from the velocity field, was found to be (2.2 ± 0.2) Sv (1 Sv = 106 m3 s-1) with a slight, but not statistically significant, positive trend. The coldest part, and probably the bulk, of the FBC overflow warmed by a bit more than 0.1 °C, especially after 2002, increasing the transport of heat into the deep ocean. This warming was, however, accompanied by increasing salinities, which seem to have compensated for the temperature-induced density decrease. Thus, the FBC overflow has remained stable in volume transport as well as density during the 2 decades from 1995 to 2015. After crossing the GSR, the overflow is modified by mixing and entrainment, but the associated change in volume (and heat) transport is still not well known. Whatever effect this has on the AMOC and the global energy balance, our observed stability of the FBC overflow is consistent with reported observations from the other main overflow branch, the Denmark Strait overflow, and the three Atlantic inflow branches to the Arctic Mediterranean that feed the overflows. If the AMOC has weakened during the last 2 decades, it is not likely

  8. NUMERICAL SIMULATION FOR THE STEPPED SPILLWAY OVERFLOW WITH TURBULENCE MODEL

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Stepped spillways have increasingly become a very important measure for flood discharge and energy dissipation. Therefore, the velocity, pressure and other characteristics of the flow on the stepped spillway should be known clearly. But so far the study for the stepped spillway overflow is only based on the model test. In this paper, the stepped spillway overflow was simulated by the Reynolds stress turbulence model. The simulation results were analyzed and compared with measured data, which shows they are satisfactory.

  9. Model-Data Intercomparison for Marginal Sea Overflows

    Science.gov (United States)

    2016-06-07

    Model -Data Intercomparison for Marginal Sea Overflows Tamay M. Özgökmen Division of Meteorology and Physical Oceanography Rosenstiel School of...ambient stratification. 3) To develop parameterizations of mixing for ocean general circulation models . 4) To explore the large-scale impact of mixing in...overflows. APPROACH The research has been been carried out using a combination of oceanic data, high-resolution nonhydrostatic numerical model , and

  10. Transports and pathways of overflow water in the Rockall Trough

    Science.gov (United States)

    Johnson, Clare; Sherwin, Toby; Cunningham, Stuart; Dumont, Estelle; Houpert, Loïc; Holliday, N. Penny

    2017-04-01

    Water mass analysis reveals a persistent core of deep overflow water within the Rockall Trough which hugs the northern and western boundaries of the basin. Mean speeds within this overflow are 10-15 cm s-1 giving a transport time from the Wyville Thomson Ridge to the central basin of banks, we suggest that the volume transport will likely increase as the flow pathway is traced back around the boundary of the Rockall Trough towards the Wyville Thomson Ridge.

  11. Recent findings on sinks for sulfide in gravity sewer networks

    DEFF Research Database (Denmark)

    Nielsen, Asbjørn Haaning; Hvitved-Jacobsen, Thorkild; Vollertsen, Jes

    2006-01-01

    summarizes this newly obtained knowledge and emphasizes important implications of the findings. Model simulations of the in-sewer processes important for the sulfur cycle showed that sulfide oxidation in the wetted biofilm is typically the most important sink for dissolved sulfide in gravity sewers. However...

  12. Tolerable Time-Varying Overflow on Grass-Covered Slopes

    Directory of Open Access Journals (Sweden)

    Steven A. Hughes

    2015-03-01

    Full Text Available Engineers require estimates of tolerable overtopping limits for grass-covered levees, dikes, and embankments that might experience steady overflow. Realistic tolerance estimates can be used for both resilient design and risk assessment. A simple framework is developed for estimating tolerable overtopping on grass-covered slopes caused by slowly-varying (in time overtopping discharge (e.g., events like storm surges or river flood waves. The framework adapts the well-known Hewlett curves of tolerable limiting velocity as a function of overflow duration. It has been hypothesized that the form of the Hewlett curves suggests that the grass erosion process is governed by the flow work on the slope above a critical threshold velocity (referred to as excess work, and the tolerable erosional limit is reached when the cumulative excess work exceeds a given value determined from the time-dependent Hewlett curves. The cumulative excess work is expressed in terms of overflow discharge above a critical discharge that slowly varies in time, similar to a discharge hydrograph. The methodology is easily applied using forecast storm surge hydrographs at specific locations where wave action is minimal. For preliminary planning purposes, when storm surge hydrographs are unavailable, hypothetical equations for the water level and overflow discharge hydrographs are proposed in terms of the values at maximum overflow and the total duration of overflow. An example application is given to illustrate use of the methodology.

  13. A biofilm model for prediction of pollutant transformation in sewers.

    Science.gov (United States)

    Jiang, Feng; Leung, Derek Hoi-Wai; Li, Shiyu; Chen, Guang-Hao; Okabe, Satoshi; van Loosdrecht, Mark C M

    2009-07-01

    This study developed a new sewer biofilm model to simulate the pollutant transformation and biofilm variation in sewers under aerobic, anoxic and anaerobic conditions. The biofilm model can describe the activities of heterotrophic, autotrophic, and sulfate-reducing bacteria (SRB) in the biofilm as well as the variations in biofilm thickness, the spatial profiles of SRB population and biofilm density. The model can describe dynamic biofilm growth, multiple biomass evolution and competitions among organic oxidation, denitrification, nitrification, sulfate reduction and sulfide oxidation in a heterogeneous biofilm growing in a sewer. The model has been extensively verified by three different approaches, including direct verification by measurement of the spatial concentration profiles of dissolved oxygen, nitrate, ammonia, and hydrogen sulfide in sewer biofilm. The spatial distribution profile of SRB in sewer biofilm was determined from the fluorescent in situ hybridization (FISH) images taken by a confocal laser scanning microscope (CLSM) and were predicted well by the model.

  14. Integrated design of sewers and wastewater treatment plants.

    Science.gov (United States)

    Vollertsen, J; Hvitved-Jacobsen, T; Ujang, Z; Talib, S A

    2002-01-01

    Sewer system design must be integrated with wastewater treatment plant design when moving towards a more sustainable urban wastewater management. This integration allows an optimization of the design of both systems to achieve a better and more cost-effective wastewater management. Hitherto integrated process design has not been an option because the tools to predict in-sewer wastewater transformations have been inadequate. In this study the WATS model--being a new and validated tool for in-sewer microbial process simulations--is presented and its application for integrated sewer and treatment plant design is exemplified. A case study on a Malaysian catchment illustrates this integration. The effects of centralization of wastewater treatment and the subsequently longer transport distances are addressed. The layout of the intercepting sewer is optimized to meet the requirements of different treatment scenarios.

  15. 21 CFR 1210.14 - Sanitary inspection of plants.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Sanitary inspection of plants. 1210.14 Section... FEDERAL IMPORT MILK ACT Inspection and Testing § 1210.14 Sanitary inspection of plants. The sanitary conditions of any plant handling milk or cream any part of which is to be shipped or transported into...

  16. 21 CFR 1210.11 - Sanitary inspection of dairy farms.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Sanitary inspection of dairy farms. 1210.11... UNDER THE FEDERAL IMPORT MILK ACT Inspection and Testing § 1210.11 Sanitary inspection of dairy farms. The sanitary conditions of any dairy farm producing milk or cream to be shipped or transported...

  17. [Safety and electromagnetic compatibility in sanitary field].

    Science.gov (United States)

    Bini, M; Feroldi, P; Ferri, C; Ignesti, A; Olmi, R; Priori, S; Riminesi, C; Tobia, L

    2012-01-01

    In sanitary field and especially in a hospital, multiple sources of non ionizing radiation are used for diagnostic and therapeutic aims. In sanitary sector both workers and users are present at the same time, and in some cases general population could need higher protection than workers in relationship to the exposition to electromagnetic fields. In order to protect health and safety of patients, general population and workers of hospitals and with the aim to identify, analyze, evaluate and study its level of significance, electrical, magnetic and electromagnetic sources Research Italian project Si.C.E.O. (Safety And Electromagnetic Compatibility In Sanitary Field) was instituted. Target of our research project was to deepen risk of exposition elements with analysis of outdoor (e.g. power lines, transmission cabinets) and indoor (e.g. equipment for physical therapy) sources, located in sanitary structures and to verify the level exposition of workers and common population end the respect of specific regulation, and finally to define technical and organizational measures really useful for protection and reduction of risk.

  18. Sanitary technology. Special issue; Sanitairtechniek. Themanummer

    Energy Technology Data Exchange (ETDEWEB)

    Lodder, H. [Deerns Raadgevende Ingenieurs, Rijswijk (Netherlands); De Veer, T. [PWN Waterleidingbedrijf Noord-Holland, Velserbroek (Netherlands); Korstanje, H.; De Gids, Ph. K. [LegioFreeWaterSystems, Wijk bij Duurstede (Netherlands); Lansbergen, A. [Itho, Schiedam (Netherlands); Scheffer, W.J.H. [UNETO-VNI, Zoetermeer (Netherlands); Van Wolferen, H. [TNO Milieu en Energie, Apeldoorn (Netherlands); Donker, H. [Kemper Nederland, Groenlo (Netherlands); Engelenburg, M. [ATECA, Den Haag (Netherlands); Wolters, J. [Tour en Andersson, Alphen aan den Rijn (Netherlands); Doldersum, R.H. [De Melker Sanitairtechniek, Veenendaal (Netherlands)

    2007-09-15

    In 11 articles attention is paid to several aspects of sanitary technology, in particular the prevention and control of legionella in heating systems and water supply installations. [Dutch] In 11 artikelen wordt aandacht besteed aan verschillende aspecten m.b.t. sanitaire techniek, in het bijzonder legionella preventie en beheer in verwarmingssystemen en leidingwaterinstallaties.

  19. 21 CFR 110.35 - Sanitary operations.

    Science.gov (United States)

    2010-04-01

    ..., when cleaning is necessary to protect against the introduction of microorganisms into food, all food... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Sanitary operations. 110.35 Section 110.35 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD...

  20. [Sanitary-hygienic assessment of microbial biofertilizer].

    Science.gov (United States)

    Arkhipchenko, N A; Akhtemava, G A; Lebedeva, T V; Voronina, A A; Makhan'kova, T I; Pavlova, M M; Shteĭntsaĭg, T A

    1991-10-01

    Biological treatment of sewage from pig-breeding complexes allowed to produce microbial biomass and primary sediments. The mixture of these components (1:1) after rendering harmless and drying out become the high effective biofertilizer. The results of chronic experiment on sanitary status of soil (microbial and helminthological indexes) under this biofertilizer usage are discussed, and the harmlessness of it is demonstrated.

  1. Consequential environmental and economic life cycle assessment of green and gray stormwater infrastructures for combined sewer systems.

    Science.gov (United States)

    Wang, Ranran; Eckelman, Matthew J; Zimmerman, Julie B

    2013-10-01

    A consequential life cycle assessment (LCA) is conducted to evaluate the trade-offs between water quality improvements and the incremental climate, resource, and economic costs of implementing green (bioretention basin, green roof, and permeable pavement) versus gray (municipal separate stormwater sewer systems, MS4) alternatives of stormwater infrastructure expansions against a baseline combined sewer system with combined sewer overflows in a typical Northeast US watershed for typical, dry, and wet years. Results show that bioretention basins can achieve water quality improvement goals (e.g., mitigating freshwater eutrophication) for the least climate and economic costs of 61 kg CO2 eq. and $98 per kg P eq. reduction, respectively. MS4 demonstrates the minimum life cycle fossil energy use of 42 kg oil eq. per kg P eq. reduction. When integrated with the expansion in stormwater infrastructure, implementation of advanced wastewater treatment processes can further reduce the impact of stormwater runoff on aquatic environment at a minimal environmental cost (77 kg CO2 eq. per kg P eq. reduction), which provides support and valuable insights for the further development of integrated management of stormwater and wastewater. The consideration of critical model parameters (i.e., precipitation intensity, land imperviousness, and infrastructure life expectancy) highlighted the importance and implications of varying local conditions and infrastructure characteristics on the costs and benefits of stormwater management. Of particular note is that the impact of MS4 on the local aquatic environment is highly dependent on local runoff quality indicating that a combined system of green infrastructure prior to MS4 potentially provides a more cost-effective improvement to local water quality.

  2. Valuing information for sewer replacement decisions.

    Science.gov (United States)

    van Riel, Wouter; Langeveld, Jeroen; Herder, Paulien; Clemens, François

    Decision-making for sewer asset management is partially based on intuition and often lacks explicit argumentation, hampering decision transparency and reproducibility. This is not to be preferred in light of public accountability and cost-effectiveness. It is unknown to what extent each decision criterion is appreciated by decision-makers. Further insight into this relative importance improves understanding of decision-making of sewer system managers. As such, a digital questionnaire (response ratio 43%), containing pairwise comparisons between 10 relevant information sources, was sent to all 407 municipalities in the Netherlands to analyse the relative importance and assess whether a shared frame of reasoning is present. Thurstone's law of comparative judgment was used for analysis, combined with several consistency tests. Results show that camera inspections were valued highest, while pipe age was considered least important. The respondents were pretty consistent per individual and also showed consistency as a group. This indicated a common framework of reasoning among the group. The feedback of the group showed, however, the respondents found it difficult to make general comparisons without having a context. This indicates decision-making in practice is more likely to be steered by other mechanisms than purely combining information sources.

  3. Storm water management implications on WWTPS in combined sewer systems: Integration strategies and process conditions; Implicaciones sobre la estacion depuradora de la gestion de aguas pluviales en los sistemas de saneamiento unitario: estrategias de integracion y afecciones sobre los procesos

    Energy Technology Data Exchange (ETDEWEB)

    Suarez Lopez, J.; Jacome Burgos, A.; Anta Alvarez, J.; Blanco Menendez, J. P.; Hernaez Oubina, D.; Rio Cambeses, H. del

    2012-07-01

    New design and strategies to manage wet weather floes in combined sewer systems, which main objective is to minimize environmental impacts on water bodies, require the treatment of large volumes of storm water. Wet weather flows introduced into combined sewer show dynamic-transient behavior both in terms of flow discharges and pollution. With traditional design strategies, large pollution peaks are spilled during rain events into water receiving bodies by combined sewer overflows (CSOs). Nowadays, CSOs have been reduced providing some storage capacity into the combined sewer systems (either in network, by means storm water tanks, or in WWTP). The stored storm water and its associated pollution should be treated. WWTP inflows during rainy events are conditioned by the local storm water management strategy. The WWTP can be overcome if it is managed using traditional dry weather strategies. In order to optimize the treatment performance and to assure that urban pollution do not reach aquatic environment, the WWTP must participate in the system in an integrated manner. This is a key element. This paper shows firstly the importance of CSO pollution and the development of new strategies for storm water management in combined sewer systems. Storm water tanks, located in the sewerage system, have been one of the most common solutions adopted but there are some experiences of wet weather flow management at the WWTP. All these strategies are revised in the paper. Once the role of the WWTP in the new combined sewer systems is known, the article presents a review about the problems generated by the hydraulic overloads and the large variations of the pollution characteristics on different stages of the water line. Special emphasis is made on the problems generated in secondary processes based on activated sludge. these problems are analysed in detail and some mitigation strategies are proposed. (Author) 20 refs.

  4. Development of Overflow-Prevention Valve with Trigger Mechanism.

    Science.gov (United States)

    Ishino, Yuji; Mizuno, Takeshi; Takasaki, Masaya

    2016-09-01

    A new overflow-prevention valve for combustible fluid is developed which uses a trigger mechanism. Loading arms for combustible fluid are used for transferring oil from a tanker to tanks and vice versa. The loading arm has a valve for preventing overflow. Overflow- prevention valves cannot use any electric component to avoid combustion. Therefore, the valve must be constructed only by mechanical parts. The conventional overflow-prevention valve uses fluid and pneumatic forces. It consists of a sensor probe, a cylinder, a main valve for shutting off the fluid and a locking mechanism for holding an open state of the main valve. The proposed overflow-prevention valve uses the pressure due to the height difference between the fluid level of the tank and the sensor probe. However, the force of the cylinder produced by the pressure is too small to release the locking mechanism. Therefore, a trigger mechanism is introduced between the cylinder and the locking mechanism. The trigger mechanism produces sufficient force to release the locking mechanism and close the main valve when the height of fluid exceeds a threshold value. A trigger mechanism is designed and fabricated. The operation necessary for closing the main valve is conformed experimentally.

  5. Radar Based Flow and Water Level Forecasting in Sewer Systems

    DEFF Research Database (Denmark)

    Thorndahl, Søren; Rasmussen, Michael R.; Grum, M.

    2009-01-01

    This paper describes the first radar based forecast of flow and/or water level in sewer systems in Denmark. The rainfall is successfully forecasted with a lead time of 1-2 hours, and flow/levels are forecasted an additional ½-1½ hours using models describing the behaviour of the sewer system. Both...... radar data and flow/water level model are continuously updated using online rain gauges and online in-sewer measurements, in order to make the best possible predictions. The project show very promising results, and show large potentials, exploiting the existing water infrastructure in future climate...

  6. Numerical Modelling Approaches for Sediment Transport in Sewer Systems

    DEFF Research Database (Denmark)

    Mark, Ole

    A study of the sediment transport processes in sewers has been carried out. Based on this study a mathematical modelling system has been developed to describe the transport processes of sediments and dissolved matter in sewer systems. The modelling system consists of three sub-models which...... constitute the basic modelling system necessary to give a discription of the most dominant physical transport processes concerning particles and dissolved matter in sewer systems: A surface model. An advection-dispersion model. A sediment transport model....

  7. A methodological approach to designing sewer system control

    DEFF Research Database (Denmark)

    Mollerup, Ane Loft

    for this thesis was therefore the wish for a methodological approach to sewer system control design. Using a case study the following research hypothesis was tested in this thesis: Using classical and modern control theory, a methodological approach can be derived for designing sewer system control. This can aid...... urban drainage planner and other professionals in the planning phase of sewer system con-trol design and effectively contribute to find novel control solution. It was investigated if the established methodology used in classic control the-ory for process control design can be applied meaningfully....... This was not unexpected, since the true potential of having optimisation arises, when a system has many control loops with limit-ing constraints and/or changing prioritisation between them. The results showed that for small sewer systems, where the complexity is limited, it is not necessarily the best option to implement...

  8. Colorado River Sewer System Joint Venture to Upgrade Wastewater System

    Science.gov (United States)

    SAN FRANCISCO -Today, the Colorado River Sewer System Joint Venture, located in Parker, Ariz. entered into an agreement with the EPA to upgrade their wastewater treatment system to meet stringent water quality standards. The cost of the upgrade is ap

  9. Safe Drinking Water Information System (SDWIS) Sewer Treatment Plants

    Data.gov (United States)

    U.S. Environmental Protection Agency — This is a point feature dataset showing the locations of sewer treatment plants. These facility locations are part of the safe drinking water information system...

  10. Development of Sediment Deposition Height Capacity Equation in Sewer Networks

    Science.gov (United States)

    Song, Yangho; Jo, Deokjun; Lee, Jungho

    2017-04-01

    Sediment characteristics and transport processes in sewers are markedly different from river. There is a wide range of particle densities and smaller particle size variation in sewers. Sediment supply and the available erodible material are more limited in sewers, and the diverse hydraulic characteristics in sewer systems are more unsteady. Prevention of sewer sediment accumulation, which can cause major sewer operational problems, is imperative and has been an immense concern for engineers. The effects of sediment formation in sewer systems, an appropriate sediment transport modelling with the ability to determine the location and depth of sediment deposit is needed. It is necessary to design efficiently considering the transfer and settling phenomena of the sediment coming into the sewer systems. During transport in the sewer, the minimum shear flow velocity and possible shear stress at which the sediment is transported smoothly. However, the interaction of sediment and fluid within the sewer systems has been very complex and the rigorous theoretical handling of this problem has not been developed. It is derived from the empirical values obtained from the river bed. The basic theory that particles float is based on the balance between sedimentation of particles by gravity and turbulent diffusion of fluids. There are many variables related. Representative parameters include complex phenomena due to collisions between particles, particles and fluids, and interactions between particles and tube walls. In general, the main parameters that form the boundary between the main transport and sediment are particle size, density, volume fraction, pipe diameter and gravity. As the particle size and volume concentration increase, the minimum feed rate increases and the same tendency is observed for the change of the capillary diameter. Based on this tendency, this study has developed a sediment deposition height capacity formula to take into consideration the sewer discharge

  11. Factors affecting economies of scale in combined sewer systems.

    Science.gov (United States)

    Maurer, Max; Wolfram, Martin; Anja, Herlyn

    2010-01-01

    A generic model is introduced that represents the combined sewer infrastructure of a settlement quantitatively. A catchment area module first calculates the length and size distribution of the required sewer pipes on the basis of rain patterns, housing densities and area size. These results are fed into the sewer-cost module in order to estimate the combined sewer costs of the entire catchment area. A detailed analysis of the relevant input parameters for Swiss settlements is used to identify the influence of size on costs. The simulation results confirm that an economy of scale exists for combined sewer systems. This is the result of two main opposing cost factors: (i) increased construction costs for larger sewer systems due to larger pipes and increased rain runoff in larger settlements, and (ii) lower costs due to higher population and building densities in larger towns. In Switzerland, the more or less organically grown settlement structures and limited land availability emphasise the second factor to show an apparent economy of scale. This modelling approach proved to be a powerful tool for understanding the underlying factors affecting the cost structure for water infrastructures.

  12. Utilities:Water:Sewer Line Nodes at Pipe Spring National Monument, Arizona (Utilities.gdb:Water:sewer_node)

    Data.gov (United States)

    National Park Service, Department of the Interior — This feature class represents sewer line nodes at Pipe Spring National Monument, Arizona. The data were collected using Trimble Global Positioning System (GPS) units...

  13. Assessment of sewer source contamination of drinking water wells using tracers and human enteric viruses.

    Science.gov (United States)

    Hunt, Randall J; Borchardt, Mark A; Richards, Kevin D; Spencer, Susan K

    2010-10-15

    This study investigated the source, transport, and occurrence of human enteric viruses in municipal well water, focusing on sanitary sewer sources. A total of 33 wells from 14 communities were sampled once for wastewater tracers and viruses. Wastewater tracers were detected in four of these wells, and five wells were virus- positive by qRT-PCR. These results, along with exclusion of wells with surface water sources, were used to select three wells for additional investigation. Viruses and wastewater tracers were found in the groundwater at all sites. Some wastewater tracers, such as ionic detergents, flame retardants, and cholesterol, were considered unambiguous evidence of wastewater. Sampling at any given time may not show concurrent virus and tracer presence; however, given sufficient sampling over time, a relation between wastewater tracers and virus occurrence was identified. Presence of infectious viruses at the wellhead demonstrates that high-capacity pumping induced sufficiently short travel times for the transport of infectious viruses. Therefore, drinking-water wells are vulnerable to contaminants that travel along fast groundwater flowpaths even if they contribute a small amount of virus-laden water to the well. These results suggest that vulnerability assessments require characterization of "low yield-fast transport" in addition to traditional "high yield-slow transport", pathways.

  14. [Modern problems of the application of sanitary regulations concerning sanitary protection zones and sanitary classification of enterprises, buildings and other facilities].

    Science.gov (United States)

    Lomtev, A Iu; Eremin, G B; Mozzhukhina, N A; Kombarova, M Iu; Mel'tser, A V; Giul'mamedov, É Iu

    2013-01-01

    In this paper there was performed an analysis of the application of sanitary norms and rules concerning sanitary protective zones and sanitary classification of enterprises, buildings and other facilities, including requirements for the sufficiency and accuracy of information in the performance of projects in sanitary protection zone (SPZ). There is presented an analysis of regulations that set requirements for implementation of mapping works in drafting the SPZ. The design of the SPZ was shown to be, on the one hand, the element of territorial planning subjects of the Russian Federation, on the other hand, the object of capital construction. The substantiations of requirements for graphic and text content, structure, and composition of data, sources of their obtaining, methods of data convergence are reported. There are revealed inconsistencies in Sanitary Regulations and Norms (SanPins) and in their relationship with the Town Planning and Land Code and other laws, and regulations adopted in their development.

  15. Sanitary effects of fossil fuels; Effets sanitaires des combustibles fossiles

    Energy Technology Data Exchange (ETDEWEB)

    Nifenecker, H. [Centre National de la Recherche Scientifique (IN2P3/CNRS), 38 - Grenoble (France)

    2006-07-01

    In this compilation are studied the sanitary effects of fossil fuels, behavioral and environmental sanitary risks. The risks in connection with the production, the transport and the distribution(casting) are also approached for the oil(petroleum), the gas and the coal. Accidents in the home are evoked. The risks due to the atmospheric pollution are seen through the components of the atmospheric pollution as well as the sanitary effects of this pollution. (N.C.)

  16. Efficient Heuristics for Simulating Population Overflow in Parallel Networks

    NARCIS (Netherlands)

    Zaburnenko, T.S.; Nicola, V.F.

    2006-01-01

    In this paper we propose a state-dependent importance sampling heuristic to estimate the probability of population overflow in networks of parallel queues. This heuristic approximates the “optimal��? state-dependent change of measure without the need for costly optimization involved in other

  17. Multi-Factor Duplicate Question Detection in Stack Overflow

    Institute of Scientific and Technical Information of China (English)

    张芸; David Lo; 夏鑫; 孙建伶

    2015-01-01

    Stack Overflow is a popular on-line question and answer site for software developers to share their experience and expertise. Among the numerous questions posted in Stack Overflow, two or more of them may express the same point and thus are duplicates of one another. Duplicate questions make Stack Overflow site maintenance harder, waste resources that could have been used to answer other questions, and cause developers to unnecessarily wait for answers that are already available. To reduce the problem of duplicate questions, Stack Overflow allows questions to be manually marked as duplicates of others. Since there are thousands of questions submitted to Stack Overflow every day, manually identifying duplicate questions is a di昋cult work. Thus, there is a need for an automated approach that can help in detecting these duplicate questions. To address the above-mentioned need, in this paper, we propose an automated approach named DUPPREDICTOR that takes a new question as input and detects potential duplicates of this question by considering multiple factors. DUPPREDICTOR extracts the title and description of a question and also tags that are attached to the question. These pieces of information (title, description, and a few tags) are mandatory information that a user needs to input when posting a question. DUPPREDICTOR then computes the latent topics of each question by using a topic model. Next, for each pair of questions, it computes four similarity scores by comparing their titles, descriptions, latent topics, and tags. These four similarity scores are finally combined together to result in a new similarity score that comprehensively considers the multiple factors. To examine the benefit of DUPPREDICTOR, we perform an experiment on a Stack Overflow dataset which contains a total of more than two million questions. The result shows that DUPPREDICTOR can achieve a recall-rate@20 score of 63.8%. We compare our approach with the standard search engine of Stack

  18. CRITICAL HYDROLOGIC CONDITIONS FOR OVERFLOW BURST OF MORAINE LAKE

    Institute of Scientific and Technical Information of China (English)

    JIANG Zhong-xin; CUI Peng; JIANG Liang-wei

    2004-01-01

    Floodwater and debris flow caused by glacial lake burst is an important land process and a serious mountain disaster in glacial area of Xizang (Tibet) Autonomous Region, and the overflow burst is mainly caused by glacial landslide falling into moraine lake. On the premise that moraine lake is full, instantaneous burst in part of the lake bank happens, as flow velocity at burst mouth caused by overflow head is higher than threshold flow velocity of glacial till. Under some supposes, d90 and d10 of the glacial till in the bank were used as the threshold sizes of coarse and fine grains respectively. Thus, the formula of calculating threshold flow velocity of uniform sand was simplified,and threshold flow velocity of glacial till was calculated with the formula. Then, with synthesis formula calculating flow velocity of instantaneous part burst, flow velocity at overflow burst mouth was calculated, and calculation formula of critical height (H0) of overflow head was derived. Overflow head was caused by volume and surge of glacial landslide falling into moraine lake, calculation formulas of ascendant height (H1) of lake water surface and surge height (H2) on burst mouth caused by glacial landslide falling into moraine lake were derived. To sum up, critical hydrologic conditions of moraine lake burst with overflow form are: the burst is inevitable as H1 >H0; the burst is possible as H1 <H0 and (H1+H2) >H0; the burst is impossible as (H1+H2) <H0. In the factors influencing the burst critical conditions, it is advantageous for the burst that scale of the lake is 105n2 range; terminal glacial till is more fine and is even more uniform; the width of overflow mouth is even smaller than the length of the bank; the landslide haslarge scale and steep slip surface; and glacial end is close to the lake. With burst of Guangxiecuo Lake in Midui Valley of the Polongzanghu River in Xizang as an example, the burst critical conditions were tested.

  19. Sanitary hot water; Eau chaude sanitaire

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-07-01

    Cegibat, the information-recommendation agency of Gaz de France for building engineering professionals, has organized this conference meeting on sanitary hot water to present the solutions proposed by Gaz de France to meet its clients requirements in terms of water quality, comfort, energy conservation and respect of the environment: quantitative aspects of the hot water needs, qualitative aspects, presentation of the Dolce Vita offer for residential buildings, gas water heaters and boilers, combined solar-thermal/natural gas solutions, key-specifications of hot water distribution systems, testimony: implementation of a gas hot water reservoir and two accumulation boilers in an apartment building for young workers. (J.S.)

  20. Postural stability assessment in sewer workers.

    Science.gov (United States)

    Kuo, W; Bhattacharya, A; Succop, P; Linz, D

    1996-01-01

    In this study, postural stability was measured with a microcomputer-based force platform as an indirect assessment of central nervous system effect in 28 sewer workers (age range 23.4 to 64.5 years, standard deviation of 8.7 years). All workers performed four 30-second postural sway tests. The organic-solvent exposure was measured by a photo-ionization detector. The photo-ionization detector was calibrated to measure volatile organic solvents in total benzene equivalence, and concentrations were measured in various parts of the plant. The mean exposure was .32 parts per million (ppm) benzene equivalent (range of .02 to .95 ppm, standard deviation .19 ppm). Based on a covariate adjusted linear multiple-regression model, a statistically significant (p organic-solvent exposure. These workers also had increased postural sway compared with a nonexposed population. The statistically significant correlation between postural sway determinations and organic-solvent exposure was surprising given the very low exposures measured. It is possible that the organic-solvent exposure might not be the causative agent, but rather that the solvents themselves correlate with some other causative exposure, ie, total volatile organics as implicated in the cause of sick-building syndrome.

  1. Sulfide elimination by intermittent nitrate dosing in sewer sediments

    Institute of Scientific and Technical Information of China (English)

    Yanchen Liu; Chen Wu; Xiaohong Zhou; David Z.Zhu; Hanchang Shi

    2015-01-01

    The formation of hydrogen sulfide in biofilms and sediments in sewer systems can cause severe pipe corrosions and health hazards,and requires expensive programs for its prevention.The aim of this study is to propose a new control strategy and the optimal condition for sulfide elimination by intermittent nitrate dosing in sewer sediments.The study was carried out based on lab-scale experiments and batch tests using real sewer sediments.The intermittent nitrate dosing mode and the optimal control condition were investigated.The results indicated that the sulfide-intermittent-elimination strategy by nitrate dosing is advantageous for controlling sulfide accumulation in sewer sediment.The oxidation-reduction potential is a sensitive indicator parameter that can reflect the control effect and the minimum N/S (nitrate/sulfide)ratio with slight excess nitrate is necessary for optimal conditions ofefficient sulfide control with lower carbon source loss.The opth-nal control condition is feasible for the sulfide elimination in sewer systems.

  2. Wastewater-Enhanced Microbial Corrosion of Concrete Sewers.

    Science.gov (United States)

    Jiang, Guangming; Zhou, Mi; Chiu, Tsz Ho; Sun, Xiaoyan; Keller, Jurg; Bond, Philip L

    2016-08-02

    Microbial corrosion of concrete in sewers is known to be caused by hydrogen sulfide, although the role of wastewater in regulating the corrosion processes is poorly understood. Flooding and splashing of wastewater in sewers periodically inoculates the concrete surface in sewer pipes. No study has systematically investigated the impacts of wastewater inoculation on the corrosion of concrete in sewers. This study investigated the development of the microbial community, sulfide uptake activity, and the change of the concrete properties for coupons subjected to periodic wastewater inoculation. The concrete coupons were exposed to different levels of hydrogen sulfide under well-controlled conditions in laboratory-scale corrosion chambers simulating real sewers. It was evident that the periodic inoculation induced higher corrosion losses of the concrete in comparison to noninoculated coupons. Instantaneous measurements such as surface pH did not reflect the cumulative corrosion losses caused by long-term microbial activity. Analysis of the long-term profiles of the sulfide uptake rate using a Gompertz model supported the enhanced corrosion activity and greater corrosion loss. The enhanced corrosion rate was due to the higher sulfide uptake rates induced by wastewater inoculation, although the increasing trend of sulfide uptake rates was slower with wastewater. Increased diversity in the corrosion-layer microbial communities was detected when the corrosion rates were higher. This coincided with the environmental conditions of increased levels of gaseous H2S and the concrete type.

  3. [Sanitary-and-epidemiologic examination of the food-products].

    Science.gov (United States)

    Sukhanov, V B; Kerimova, M G; Elizarova, E V

    2011-01-01

    Some aspects of sanitary and epidemiologic examination of food products are considered. The examination is an important part of sanitary and epidemiologic control and surveillance in the sphere of food safety and quality, consumer rights protection, consumer market and human welfare.

  4. EXAMINATION AND TESTING OF CRANE BEAMS OF AN OVERFLOW DAM

    Directory of Open Access Journals (Sweden)

    Kholopov Igor' Serafimovich

    2012-10-01

    Full Text Available The following conclusions were made upon completion of the testing of crane beams: The lowest rigidity is demonstrated by welded beams exposed to temporary mobile loads; the maximal buckling caused by temporary mobile loads is equal to 12 mm, or 1/1,1790 of the span; the rigidity of crane beams of an overflow dam meets the requirements set by Section E2.1 of Construction Rules 20.13330.2011 "Loads and Actions". In general, the authors state that the crane beams of the span structure of the overflow dam are in a serviceable operating condition, according to their opinion issued upon completion of examination and testing procedures. The recommendation is to regularly tighten screw nuts and to install high-strength bolts in the points of missing rivets. The authors also recommend applying a rust-proofing coating to all metal structures of the dam spans.

  5. Method of Preventing Buffer Overflow Attacks by Intercepting DLL Functions

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The way of intercepting Windows DLL functions against buffer overflow attacks is evaluated. It's produced at the expense of hooking vulnerable DLL functions by addition of check code. If the return address in the stack belongs to a heap or stack page, the call is from illicit code and the program is terminated. The signature of malicious code is recorded, so it is possible for the next attack to be filtered out. The return-into-libc attacks are detected by comparing the entry address of DLL functions with the overwritten return address in the stack. The presented method interrupts the execution of malicious code and prevents the system from being hijacked when these intercepted DLL functions are invoked in the context of buffer overflow.

  6. Increasing NADH oxidation reduces overflow metabolism in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Vemuri, Goutham; Eiteman, M.A; McEwen, J.E

    2007-01-01

    Respiratory metabolism plays an important role in energy production in the form of ATP in all aerobically growing cells. However, a limitation in respiratory capacity results in overflow metabolism, leading to the formation of byproducts, a phenomenon known as ‘‘overflow metabolism’’ or ‘‘the...... Crabtree effect.’’ The yeast Saccharomyces cerevisiae has served as an important model organism for studying the Crabtree effect. When subjected to increasing glycolytic fluxes under aerobic conditions, there is a threshold value of the glucose uptake rate at which the metabolism shifts from purely...... by overexpression of a water-forming NADH oxidase reduced aerobic glycerol formation. The metabolic response to elevated alternative oxidase occurred predominantly in the mitochondria, whereas NADH oxidase affected genes that catalyze cytosolic reactions. Moreover, NADH oxidase restored the deficiency of cytosolic...

  7. A Novel Nanometric Reversible Signed Divider with Overflow Checking Capability

    Directory of Open Access Journals (Sweden)

    Faraz Dastan

    2012-03-01

    Full Text Available One of the best approaches for designing future computers is that we use reversible logic. Reversible logic circuits have lower power consumption than the common circuits, used in computers nowadays. In this study we propose a new reversible division circuit. This reversible division circuit is signed divider and has an overflow checking capability. Among the designed and proposed reversible division circuits, our proposed division circuit is the first reversible signed divider with overflow checking capability which has been designed. In this circuit we use some reversible components like reversible parallel adder, reversible left-shift register, reversible multiplexer, reversible n-bit register and reversible n-bit register with parallel load line. In this paper all the scales are in the nanometric area.

  8. Research on Overflow Monitoring Mechanism Based on Downhole Microflow Detection

    Directory of Open Access Journals (Sweden)

    Liang Ge

    2014-01-01

    Full Text Available The flow rate variation of the drilling fluid and micro-overflow loss is difficult to analyze. The purpose to prevent the occurrence of kick, lost circulation, and other complex conditions is not easy to be achieved. Therefore, the microflow-induced annulus multiphase flow rate and annulus pressure field model were studied, and a downhole microflow measurement system has been developed. A differential pressure type flow measurement was used in the system, and real-time downhole information was obtained to achieve deep, narrow windows and other safety-density complex formation security. This paper introduced a new bottom-hole flow meter which can measure the annular flux while drilling and monitor overflow and circulation loss. The accuracy and reliability of the MPD (managed pressure drilling system can be improved obviously by applying the device; as a result, the safety of drilling is enhanced and the cost is reduced.

  9. Comparison of core sampling and visual inspection for assessment of sewer pipe condition

    NARCIS (Netherlands)

    Stanic, N.; Haan, C.; Tirion, M.; Langeveld, J.G.; Clemens, F.H.L.R.

    2012-01-01

    Sewer systems are costly to construct and even more costly to replace, requiring proper asset management Sewer asset management relies to a large extent on available information. In sewer systems where pipe corrosion is the dominant failure mechanism, visual inspection (CCTV) and core sampling are a

  10. 40 CFR 35.935-16 - Sewer use ordinance and evaluation/rehabilitation program.

    Science.gov (United States)

    2010-07-01

    .../rehabilitation program. 35.935-16 Section 35.935-16 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY...-Clean Water Act § 35.935-16 Sewer use ordinance and evaluation/rehabilitation program. (a) The grantee... sewer use ordinance, and the grantee is complying with the sewer system evaluation and...

  11. Comparison of core sampling and visual inspection for assessment of sewer pipe condition

    NARCIS (Netherlands)

    Stanic, N.; Haan, C.; Tirion, M.; Langeveld, J.G.; Clemens, F.H.L.R.

    2012-01-01

    Sewer systems are costly to construct and even more costly to replace, requiring proper asset management Sewer asset management relies to a large extent on available information. In sewer systems where pipe corrosion is the dominant failure mechanism, visual inspection (CCTV) and core sampling are a

  12. Comparison of core sampling and visual inspection for assessment of sewer pipe condition

    NARCIS (Netherlands)

    Stanic, N.; Haan, C.; Tirion, M.; Langeveld, J.G.; Clemens, F.H.L.R.

    2012-01-01

    Sewer systems are costly to construct and even more costly to replace, requiring proper asset management Sewer asset management relies to a large extent on available information. In sewer systems where pipe corrosion is the dominant failure mechanism, visual inspection (CCTV) and core sampling are

  13. Long-term pollution simulation in combined sewer networks.

    Science.gov (United States)

    Masse, B; Zug, M; Tabuchi, J P; Tisserand, B

    2001-01-01

    This paper presents results of long term pollution simulations on the example of the sewerage system of Grand-Couronne. This modelling work is part of a study where objective is to develop a method to define the reference flow of a WWTP. The model HYDROWORKS DM has been successfully validated in hydraulics and pollution for the sewer network, for long time simulations. A conceptual model has been built to model the pollution in the tank at the outlet of the combined system. One synthetic year of rain has been used to simulate the working of the "up stream system" of the WWTP (combined sewer + tank + separate sewer + pre-treatments) and has been successfully validated by measurements of the 1998-1999 year. If this paper is focused on the "up stream system", the SIMBA/SIMBAD WWTP model has been successfully calibrated and validated too, and the combination represents a fully validated "Integrated Model" for the sewerage system.

  14. Wind forcing of salinity anomalies in the Denmark Strait overflow

    Directory of Open Access Journals (Sweden)

    S. Hall

    2011-06-01

    Full Text Available The overflow of dense water from the Nordic Seas to the North Atlantic through Denmark Strait is an important part of the global thermohaline circulation. The salinity of the overflow plume has been measured by an array of current meters across the continental slope off the coast of Angmagssalik, southeast Greenland since September 1998. During 2004 the salinity of the overflow plume changed dramatically, with the entire width of the array (70 km freshening between January 2004 and July 2004, with a significant negative salinity anomaly of about 0.06 in May. The event in May represents a fresh anomaly of over 3 standard deviations from the mean since recording began in 1998. We show that the OCCAM 1/12° Ocean General Circulation Model not only reproduces the 2004 freshening event (r=0.96, p<0.01, but also correlates well with salinity observations over a previous 6 year period (r=0.54, p<0.01. Consequently the physical processes causing the 2004 anomaly and prior variability in salinity are investigated using the model output. Our results reject the hypotheses that the anomaly is caused by processes occurring between the overflow sill and the moorings, or by an increase in upstream net freshwater input. Instead, we show that the 2004 salinity anomaly is caused by an increase in volume flux of low salinity water, with a potential density greater than 27.60 kg m−3, flowing towards the Denmark Strait sill in the East Greenland Current. This is caused by an increase of southward wind stress upstream of the sill at around 75° N 20° W four and a half months earlier, and an associated spin-up of the Greenland Sea Gyre.

  15. Tidal Decay and Roche-Lobe Overflow of Gaseous Exoplanets

    Science.gov (United States)

    Jackson, Brian; Jensen, Emily; Peacock, Sarah; Arras, Phil; Penev, Kaloyan

    2016-10-01

    Many gaseous exoplanets in short-period orbits are on the verge or are in the process of Roche-lobe overflow (RLO). Moreover, orbital stability analysis shows tides can drive many hot Jupiters to spiral inevitably toward their host stars, and the distributions of orbital periods and semi-major axes point to non-negligible orbital decay during the main sequence lifetimes of the host stars. Thus, the coupled processes of orbital evolution and RLO likely shape the observed distribution of close-in exoplanets. However, the exact outcome for an overflowing planet depends on its internal response to mass loss, and the accompanying orbital evolution can act to enhance or inhibit RLO. Applying the Modules for Experiments in Stellar Astrophysics (MESA) suite to model RLO, we find that, although the detailed evolution may depend on several properties of the planetary system, it is largely determined by the core mass of the overflowing gas giant. In particular, we find that the orbital expansion that accompanies RLO often stops and reverses at a specific maximum period that depends on the core mass. We suggest that RLO may often strand the remnant of a gas giant near or interior to this orbital period, providing an observational prediction that can corroborate the RLO hypothesis. We conduct a preliminary comparison of this prediction to the observed population of small, short-period planets and find some planets in orbits that may be consistent with this picture.

  16. Binary Evolution: Roche Lobe Overflow and Blue Stragglers

    Science.gov (United States)

    Ivanova, Natalia

    One of the principal mechanisms that is responsible for the origin of blue stragglers is mass transfer that takes place while one of the binary companions overfills its Roche lobe. In this Chapter, we overview the theoretical understanding of mass transfer via Roche lobe overflow: classification, how both the donor and of the accretor respond to the mass transfer on different timescales (adiabatic response, equilibrium response, superadiabatic response, time-dependent response) for different types of their envelopes (convective and radiative). These responses, as well as the assumption on how liberal the process is, are discussed in terms of the stability of the ensuing mass transfer. The predictions of the theory of mass transfer via Roche lobe overflow are then briefly compared with the observed mass-transferring systems with both degenerate and non-degenerate donors. We conclude with the discussion which cases of mass transfer and which primordial binaries could be responsible for blue stragglers formation via Roche lobe overflow, as well as how this can be enhanced for blue stragglers formed in globular clusters

  17. Gene Expression Changes in Venous Segment of Overflow Arteriovenous Fistula

    Directory of Open Access Journals (Sweden)

    Yasuhiro Hashimoto

    2013-01-01

    Full Text Available Aim. The objective of this study was to characterize coordinated molecular changes in the structure and composition of the walls of venous segments of arteriovenous (AV fistulas evoked by overflow. Methods. Venous tissue samples were collected from 6 hemodialysis patients with AV fistulas exposed to overflow and from the normal cephalic veins of 4 other hemodialysis patients. Total RNA was extracted from the venous tissue samples, and gene expression between the 2 groups was compared using Whole Human Genome DNA microarray 44 K. Microarray data were analyzed by GeneSpring GX software and Ingenuity Pathway Analysis. Results. The cDNA microarray analysis identified 397 upregulated genes and 456 downregulated genes. Gene ontology analysis with GeneSpring GX software revealed that biological developmental processes and glycosaminoglycan binding were the most upregulated. In addition, most upregulation occurred extracellularly. In the pathway analysis, the TGF beta signaling pathway, cytokines and inflammatory response pathway, hypertrophy model, and the myometrial relaxation and contraction pathway were significantly upregulated compared with the control cephalic vein. Conclusion. Combining microarray results and pathway information available via the Internet provided biological insight into the structure and composition of the venous wall of overflow AV fistulas.

  18. Two Overflows in the Northern Gulf of California

    Science.gov (United States)

    López, M.; Candela, J.; García, J.

    2007-05-01

    Two overflows in the Northern Gulf of California are marked by strong average slopes of 15 and 5%. The long term (~ a year) average current at both sills is bottom intensified with average speeds of about 30 and 15 cm/s, respectively. At both sills there are strong tidal currents, but the low-frequency currents are quite persistent with very few flow reversals. Near-bottom stratification upstream (with respect to the overflows) of both sills is relatively strong, but downstream of the sills the near-bottom water is very well mixed and the bottom density is essentially the same as the one found at the sills, despite the almost two-fold (~ 600 m) and more than three-fold (~ 1500 m) increase in depth at the downstream basins. The homogenization of a thick bottom layer downstream, albeit close to the sills, is indicative of very strong mixing. These hydrographic patterns were observed during three different seasons. These results indicate that the deep water in Ballenas Channel is renewed by these overflows which enter at sill depths of ≤ 400 m and which are capable of reaching the deepest part of the basin at ~ 1500 m.

  19. Controlled overflowing of data-intensive jobs from oversubscribed sites

    Science.gov (United States)

    Sfiligoi, I.; Wuerthwein, F.; Bockelman, B.; Bradley, D. C.; Tadel, M.; Bloom, K.; Letts, J.; Mrak Tadel, A.

    2012-12-01

    The CMS analysis computing model was always relying on jobs running near the data, with data allocation between CMS compute centers organized at management level, based on expected needs of the CMS community. While this model provided high CPU utilization during job run times, there were times when a large fraction of CPUs at certain sites were sitting idle due to lack of demand, all while Terabytes of data were never accessed. To improve the utilization of both CPU and disks, CMS is moving toward controlled overflowing of jobs from sites that have data but are oversubscribed to others with spare CPU and network capacity, with those jobs accessing the data through real time Xrootd streaming over WAN. The major limiting factor for remote data access is the ability of the source storage system to serve such data, so the number of jobs accessing it must be carefully controlled. The CMS approach to this is to implement the overflowing by means of glideinWMS, a Condor based pilot system, and by providing the WMS with the known storage limits and let it schedule jobs within those limits. This paper presents the detailed architecture of the overflow-enabled glideinWMS system, together with operational experience of the past 6 months.

  20. Migrating Storms and Optimal Control of Urban Sewer Networks

    Directory of Open Access Journals (Sweden)

    Upaka Rathnayake

    2015-11-01

    Full Text Available Uniform storms are generally applied in most of the research on sewer systems. This is for modeling simplicity. However, in the real world, these conditions may not be applicable. It is very important to consider the migration behavior of storms not only in the design of combined sewers, but also in controlling them. Therefore, this research was carried out to improve Rathnayake and Tanyimboh’s optimal control algorithm for migrating storms. Promising results were found from the model improvement. Feasible solutions were obtained from the multi-objective optimization and, in addition, the role of on-line storage tanks was well placed.

  1. Risk assessment of sewer condition using artificial intelligence tools: application to the SANEST sewer system.

    Science.gov (United States)

    Sousa, V; Matos, J P; Almeida, N; Saldanha Matos, J

    2014-01-01

    Operation, maintenance and rehabilitation comprise the main concerns of wastewater infrastructure asset management. Given the nature of the service provided by a wastewater system and the characteristics of the supporting infrastructure, technical issues are relevant to support asset management decisions. In particular, in densely urbanized areas served by large, complex and aging sewer networks, the sustainability of the infrastructures largely depends on the implementation of an efficient asset management system. The efficiency of such a system may be enhanced with technical decision support tools. This paper describes the role of artificial intelligence tools such as artificial neural networks and support vector machines for assisting the planning of operation and maintenance activities of wastewater infrastructures. A case study of the application of this type of tool to the wastewater infrastructures of Sistema de Saneamento da Costa do Estoril is presented.

  2. Solar sanitary system (SOL-SAN)

    Energy Technology Data Exchange (ETDEWEB)

    Cobb, J.C.

    1996-11-01

    Ordinary composting toilets, because of cooling by evaporation, do not heat the product (humus) hot enough to kill all pathogenic viruses, bacteria, or parasite eggs and cysts. The SOL-SAN system uses direct radiation to pasteurize incoming river water for drinking and also, separately, to pasteurize and dry the humus, and to pasteurize the effluent gray/brown water. Work is in progress on simple fool-proof methods of insuring that the water will not flow out unless it has been pasteurized. Heat exchangers recapture the heat from these very hot pasteurized liquids, thereby warming more in-coming water for washing, which is important for preventing transmission of pathogenic microbes. When pasteurized, the humus and gray/brown water can safely be recycled to fertilize and water the family vegetable garden. Thus no sewer would be needed, and the vegetables or fish would grow well. Widespread use of the SOL-SAN system would save water and nutrients, reduce the prevalence of infectious diseases, improve the nutrition and vitality of the population, and save the large fraction of human food now consumed by parasites.

  3. Damage estimation of sewer pipe using subtitles of CCTV inspection video

    Science.gov (United States)

    Park, Kitae; Kim, Byeongcheol; Kim, Taeheon; Seo, Dongwoo

    2017-04-01

    Recent frequent occurrence of urban sinkhole serves as a momentum of the periodic inspection of sewer pipelines. Sewer inspection using a CCTV device needs a lot of time and efforts. Many of previous studies which reduce the laborious tasks are mainly interested in the developments of image processing S/W and exploring H/W. And there has been no attempt to find meaningful information from the existing CCTV images stored by the sewer maintenance manager. This study adopts a cross-correlation based image processing method and extracts sewer inspection device's location data from CCTV images. As a result of the analysis of location-time relation, it show strong correlation between device stand time and the sewer damages. In case of using this method to investigate sewer inspection CCTV images, it will save the investigator's efforts and improve sewer maintenance efficiency and reliability.

  4. Modeling Sulfides, pH and Hydrogen Sulfide Gas in the Sewers of San Francisco

    DEFF Research Database (Denmark)

    Vollertsen, Jes; Revilla, Nohemy; Hvitved-Jacobsen, Thorkild

    2015-01-01

    An extensive measuring campaign targeted on sewer odor problems was undertaken in San Francisco. It was assessed whether a conceptual sewer process model could reproduce the measured concentrations of total sulfide in the wastewater and H2S gas in the sewer atmosphere, and to which degree...... such simulations have potential for further improving odor and sulfide management. The campaign covered measurement of wastewater sulfide by grab sampling and diurnal sampling, and H2S gas in the sewer atmosphere was logged. The tested model was based on the Wastewater Aerobic/Anaerobic Transformations in Sewers...... (WATS) sewer process concept, which never had been calibrated to such an extensive dataset. The study showed that the model was capable of reproducing the general levels of wastewater sulfide, wastewater pH, and sewer H2S gas. It could also reproduce the general variability of these parameters, albeit...

  5. Measurements and Computations of Transients in Pumped Sewer Plastic Mains

    DEFF Research Database (Denmark)

    Larsen, Torben; Burrows, Richard

    1992-01-01

    Measurements of pressure and flow in a number of pumped plastic sewer mains have been carried out in order to compare the actual observed transients with computations. Primarily the situation following pump run-down has been studied. The investigation covered pipelines with steadily rising length...

  6. 40 CFR 35.927 - Sewer system evaluation and rehabilitation.

    Science.gov (United States)

    2010-07-01

    ... rehabilitation. 35.927 Section 35.927 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER... § 35.927 Sewer system evaluation and rehabilitation. (a) All applicants for step 2 or step 3 grant... evaluation survey and, if appropriate, a program, including an estimate of costs, for rehabilitation of...

  7. Incorporating Storm Sewer Exfiltration into SWMM: Proof of Concept

    Science.gov (United States)

    This study evaluates the peak flow and volume reduction achieved by exfiltration from a perforated storm sewer in an urban catchment. There are three related objectives: [1] quantify peak flow and volume reduction; [2] demonstrate adaptability to climate change; and [3] evaluate ...

  8. Online dissolved methane and total dissolved sulfide measurement in sewers.

    Science.gov (United States)

    Liu, Yiwen; Sharma, Keshab R; Fluggen, Markus; O'Halloran, Kelly; Murthy, Sudhir; Yuan, Zhiguo

    2015-01-01

    Recent studies using short-term manual sampling of sewage followed by off-line laboratory gas chromatography (GC) measurement have shown that a substantial amount of dissolved methane is produced in sewer systems. However, only limited data has been acquired to date due to the low frequency and short span of this method, which cannot capture the dynamic variations of in-sewer dissolved methane concentrations. In this study, a newly developed online measuring device was used to monitor dissolved methane concentrations at the end of a rising main sewer network, over two periods of three weeks each, in summer and early winter, respectively. This device uses an online gas-phase methane sensor to measure methane under equilibrium conditions after being stripped from the sewage. The data are then converted to liquid-phase methane concentrations according to Henry's Law. The detection limit and range are suitable for sewer application and can be adjusted by varying the ratio of liquid-to-gas phase volume settings. The measurement presented good linearity (R² > 0.95) during field application, when compared to off-line measurements. The overall data set showed a wide variation in dissolved methane concentration of 5-15 mg/L in summer and 3.5-12 mg/L in winter, resulting in a significant average daily production of 24.6 and 19.0 kg-CH₄/d, respectively, from the network with a daily average sewage flow of 2840 m³/day. The dissolved methane concentration demonstrated a clear diurnal pattern coinciding with flow and sulfide fluctuation, implying a relationship with the wastewater hydraulic retention time (HRT). The total dissolved sulfide (TDS) concentration in sewers can be determined simultaneously with the same principle.

  9. Network condition simulator for benchmarking sewer deterioration models.

    Science.gov (United States)

    Scheidegger, A; Hug, T; Rieckermann, J; Maurer, M

    2011-10-15

    An accurate description of aging and deterioration of urban drainage systems is necessary for optimal investment and rehabilitation planning. Due to a general lack of suitable datasets, network condition models are rarely validated, and if so with varying levels of success. We therefore propose a novel network condition simulator (NetCoS) that produces a synthetic population of sewer sections with a given condition-class distribution. NetCoS can be used to benchmark deterioration models and guide utilities in the selection of appropriate models and data management strategies. The underlying probabilistic model considers three main processes: a) deterioration, b) replacement policy, and c) expansions of the sewer network. The deterioration model features a semi-Markov chain that uses transition probabilities based on user-defined survival functions. The replacement policy is approximated with a condition-class dependent probability of replacing a sewer pipe. The model then simulates the course of the sewer sections from the installation of the first line to the present, adding new pipes based on the defined replacement and expansion program. We demonstrate the usefulness of NetCoS in two examples where we quantify the influence of incomplete data and inspection frequency on the parameter estimation of a cohort survival model and a Markov deterioration model. Our results show that typical available sewer inventory data with discarded historical data overestimate the average life expectancy by up to 200 years. Although NetCoS cannot prove the validity of a particular deterioration model, it is useful to reveal its possible limitations and shortcomings and quantifies the effects of missing or uncertain data. Future developments should include additional processes, for example to investigate the long-term effect of pipe rehabilitation measures, such as inliners. Copyright © 2011 Elsevier Ltd. All rights reserved.

  10. Levee Breach Experiment by Overflow at the Full Scale Experimental Channel

    Science.gov (United States)

    Shimada, T.; Yokoyama, H.

    2010-12-01

    The increased occurrence of storm disasters caused by typhoons and local downpours in recent years has given rise to concerns over the possibility of large-scale floods resulting from river overflow. Levee breaches cause particularly severe damage, and in Japan, more than 80% of such accidents in the past have been attributed to overflow. Studies on levee breach by overflow have been conducted from various viewpoints using diverse methods. However, the mechanism of three-dimensional levee breach by overflow has not been clarified in past studies. Elucidation of this mechanism is very important for disaster prevention as well as for the future progress of studies on levee breach by overflow. Levees (levee crown width; 3m, levee height; 3m, levee length; 80m) were built in the Chiyoda Experimental Channel (full-scale experimental channel; width is 30m, length is 1,300m, maximum discharge is 170t/s) in Hokkaido Japan in 2010, and a three-dimensional experiment on levee breach by overflow. The findings of the experiment are as follows: After the beginning of overflow, levee breach widening did not begin until after most of the levee section had collapsed. It was also considered that, even if overflow occurred, extremely serious damage (e.g., sudden increase in levee breach width and overflow discharge) was unlikely unless the majority of the levee section collapsed.

  11. An Buffer Overflow Automatic Detection MethodBased on Operation Semantic

    Institute of Scientific and Technical Information of China (English)

    ZHAO Dong-fan; LIU Lei

    2005-01-01

    Buffer overflow is the most dangerous attack method that can be exploited. According to the statistics of Computer Emergency Readiness Team(CERT), buffer overflow accounts for 50% of the current software vulnerabilities, and this ratio is going up. Considering a subset of C language, Mini C, this paper presents an abstract machine model that can realize buffer overflow detection, which is based on operation semantic. Thus the research on buffer overflow detection can be built on strict descriptions of operation semantic. Not only the correctness can be assured, but also the system can be realized and extended easily.

  12. Analysis of Two-Level Support Systems with Time-Dependent Overflow - A Banking Application

    DEFF Research Database (Denmark)

    Barth, Wolfgang; Manitz, Michael; Stolletz, Raik

    2010-01-01

    is available. The analysis of such a system with time-dependent overflow is reduced to the analysis of a continuous-time Markov chain with state-dependent overflow probabilities. To approximate the system with time-dependent overflow, some waiting-based performance measures are modified. Numerical results......In this paper, we analyze the performance of call centers of financial service providers with two levels of support and a time-dependent overflow mechanism. Waiting calls from the front-office queue flow over to the back office if a waiting-time limit is reached and at least one back-office agent...

  13. Indoor Environmental Conditions and Sanitary Practices in Selected ...

    African Journals Online (AJOL)

    African Journal of Sustainable Development ... Rapidly urbanizing cities are witnessing an increase in Day care centres (DCCs) whose ... Keywords: Day Care Centres, sanitary practices, indoor air quality, children, urban communities ...

  14. Sanitary and Phytosanitary Measures in NAFTA: The Canada Experience

    OpenAIRE

    Terry Norman

    2005-01-01

    Canada's Experience in Implementing the Sanitary and Phytosanitary (SPS) provisions of the North American free trade agreement (NAFTA). The NAFTA has been a major success story for Canada since its entry into force on January 1, 1994.

  15. Developments in sanitary techniques 2011-2012. Important progress through studies in 2011; Ontwikkelingen sanitaire technieken 2011-2012. Belangrijke vorderingen door studies in 2011

    Energy Technology Data Exchange (ETDEWEB)

    Scheffer, W.

    2011-12-15

    In 2011, new laws and regulations were the main theme in sanitary techniques (ST). Libraries have been updated in the areas of tap water installations and sewer systems of buildings. Some important progress was made in the framework of several ST preliminary studies conducted by TVVL and Uneto-VNI. Still, the start-up of new ST studies and projects in 2012 is lagging behind compared to previous years. [Dutch] Het vakgebied van sanitaire technieken (ST) stond in 2011 vooral in het teken van nieuwe wet- en regelgeving. Zowel op het gebied van leidingwaterinstallaties als riolering van bouwwerken zijn de bibliotheken geactualiseerd. In het kader van enkele ST-voorstudies, uitgevoerd door TVVL en Uneto-VNI zijn belangrijke vorderingen gemaakt. De opstart van nieuwe ST-studies en -projecten in 2012 blijft echter achter ten opzichte van voorgaande jaren.

  16. Correlations in Output and Overflow Traffic Processes in Simple Queues

    Directory of Open Access Journals (Sweden)

    Don McNickle

    2007-01-01

    Full Text Available We consider some simple Markov and Erlang queues with limited storage space. Although the departure processes from some such systems are known to be Poisson, they actually consist of the superposition of two complex correlated processes, the overflow process and the output process. We measure the cross-correlation between the counting processes for these two processes. It turns out that this can be positive, negative, or even zero (without implying independence. The models suggest some general principles on how big these correlations are, and when they are important. This may suggest when renewal or moment approximations to similar processes will be successful, and when they will not.

  17. Model studies of dense water overflows in the Faroese Channels

    Science.gov (United States)

    Cuthbertson, Alan; Davies, Peter; Stashchuk, Nataliya; Vlasenko, Vasiliy

    2014-01-01

    The overflow of dense water from the Nordic Seas through the Faroese Channel system was investigated through combined laboratory experiments and numerical simulations using the Massachusetts Institute of Technology General Circulation Model. In the experimental study, a scaled, topographic representation of the Faroe-Shetland Channel, Wyville-Thomson Basin and Ridge and Faroe Bank Channel seabed bathymetry was constructed and mounted in a rotating tank. A series of parametric experiments was conducted using dye-tracing and drogue-tracking techniques to investigate deep-water overflow pathways and circulation patterns within the modelled region. In addition, the structure of the outflowing dense bottom water was investigated through density profiling along three cross-channel transects located in the Wyville-Thomson Basin and the converging, up-sloping approach to the Faroe Bank Channel. Results from the dye-tracing studies demonstrate a range of parametric conditions under which dense water overflow across the Wyville-Thomson Ridge is shown to occur, as defined by the Burger number, a non-dimensional length ratio and a dimensionless dense water volume flux parameter specified at the Faroe-Shetland Channel inlet boundary. Drogue-tracking measurements reveal the complex nature of flow paths and circulations generated in the modelled topography, particularly the development of a large anti-cyclonic gyre in the Wyville-Thompson Basin and up-sloping approach to the Faroe Bank Channel, which diverts the dense water outflow from the Faroese shelf towards the Wyville-Thomson Ridge, potentially promoting dense water spillage across the ridge itself. The presence of this circulation is also indicated by associated undulations in density isopycnals across the Wyville-Thomson Basin. Numerical simulations of parametric test cases for the main outflow pathways and density structure in a similarly-scaled Faroese Channels model domain indicate excellent qualitative agreement with

  18. Ammonia nitrogen desorption from sanitary landfill leachate in filling towers

    OpenAIRE

    Leite,Valderi D.; Barros,Aldre J. M.; Lopes,Wilton S.; Sousa,José T. de

    2014-01-01

    Sanitary landfill leachates present high concentrations of carbonaceous and nitrogenous materials. The crucial point is that carbonaceous materials are of difficult biodegradation, what compromises the performance of biological treatment processes, while nitrogenous materials, such as ammonia nitrogen, probably preclude the use of biological treatments. Therefore, the aim of this work was to study the desorption process of ammonia nitrogen from sanitary landfill leachate in filling towers. De...

  19. Charles Dickens and the movement for sanitary reform.

    Science.gov (United States)

    Litsios, Socrates

    2003-01-01

    Charles Dickens's adult life parallels the period when the movement for sanitary reform took root in England. Although he was not one of its leaders, he became in time one of its most outspoken advocates. This essay describes Dickens's growing involvement in the sanitary movement and looks at one of the most important ways he supported it--articles published in his weekly journal Household Words

  20. Electrochemical treatment of leachates from sanitary landfills

    Directory of Open Access Journals (Sweden)

    ANNABEL FERNANDES

    2013-06-01

    Full Text Available The electrochemical treatment of leachate samples from a Portuguese intermunicipal sanitary landfill was carried out using anodic oxidation. The treatment was performed in a pilot plant that possesses an electrochemical cell, with boron-doped diamond electrodes, working in batch mode with recirculation. The influence of the applied current density and the flow rate on the performance of the electrochemical oxidation was investigated. Current density was decreased by steps, during the degradation, in order to study this effect on the efficiency of the process. For the assays run at equal flow rate and initial current intensity, chemical oxygen demand (COD removal seems to depend mainly on the charge passed and the variation of the current density during the anodic oxidation process can reduce the energetic costs. An increase in the recirculation flow rate leads to an increase in the organic load removal rate and a consequent decrease in the energetic costs, but it decreases the nitrogen removal rate. Also, the bias between dissolved organic carbon and COD removals increases with flow rate, indicating that an increase in recirculation flow rate decreases the mineralization index.

  1. Sulfide and methane production in sewer sediments: Field survey and model evaluation.

    Science.gov (United States)

    Liu, Yiwen; Tugtas, A Evren; Sharma, Keshab R; Ni, Bing-Jie; Yuan, Zhiguo

    2016-02-01

    Sewer sediment processes have been reported to significantly contribute to overall sulfide and methane production in sewers, at a scale comparable to that of sewer biofilms. The physiochemical and biological characteristics of sewer sediments are heterogeneous; however, the variability of in-sediments sulfide and methane production rates among sewers has not been assessed to date. In this study, five sewer sediment samples were collected from two cities in Australia with different climatic conditions. Batch assays were conducted to determine the rates of sulfate reduction and methane production under different flow velocity (shear stress) conditions as well as under completely mixed conditions. The tests showed substantial and variable sulfate reduction and methane production activities among different sediments. Sulfate reduction and methane production from sewer sediments were confirmed to be areal processes, and were dependent on flow velocity/shear stress. Despite of the varying characteristics and reactions kinetics, the sulfate reduction and methane production processes in all sediments could be well described by a one-dimensional sewer sediment model recently developed based on results obtained from a laboratory sewer sediment reactor. Model simulations indicated that the in-situ contribution of sewer sediment emissions could be estimated without the requirement of measuring the specific sediment characteristics or the sediment depths.

  2. Mixing and transformation in the Denmark Strait Overflow

    Science.gov (United States)

    Koszalka, Inga; Haine, Thomas; Magaldi, Marcello

    2014-05-01

    The Denmark Strait Overflow (DSO) is one of the major export routes for the dense waters from the Nordic Seas to the North Atlantic. However, the observations of the DSO are limited to a few locations and poorly resolve mixing processes that transform the dense waters and hence influence propagation of hydrographic signals from the Arctic to the Atlantic. We use a high resolution circulation model to diagnose mixing processes involving the DSO in the Irminger Basin. We focus on mesoscale (10-100km) processes, the most prominent being dense cyclonic boluses making up the overflow plume. The subgrid turbulent processes are represented by the K-profile parameterization. We map the horizontal and vertical eddy diffusivities derived from Lagrangian particles, the model vertical mixing coefficient and eddy fluxes. Our results are consistent with observations suggesting enhanced vertical mixing during the initial (~ 200km) descent of the dense plume and increasing importance of horizontal mixing downstream. The model also shows enhanced mixing along the dense water pathways in the Kangerdlugssuaq Trough on the East Greenland Shelf involving fresh Polar Waters. However, the most intense mixing is induced by mesoscale boluses of dense water cascading down the sill and the associated internal wave field. Frequent occurrence of a neutrally stratified mixed layer in the dense plume poses a challenge for the turbulent scheme of the model. We advocate for an observational campaign that would corroborate these results and help develop novel parametrizations of the vertical mixing processes in the DSO.

  3. Controlled overflowing of data-intensive jobs from oversubscribed sites

    CERN Document Server

    Sfiligoi, Igor; Bockelman, Brian Paul; Bradley, Daniel Charles; Tadel, Matevz; Bloom, Kenneth Arthur; Letts, James; Mrak Tadel, Alja

    2012-01-01

    The CMS analysis computing model was always relying on jobs running near the data, with data allocation between CMS compute centers organized at management level, based on expected needs of the CMS community. While this model provided high CPU utilization during job run times, there were times when a large fraction of CPUs at certain sites were sitting idle due to lack of demand, all while Terabytes of data were never accessed. To improve the utilization of both CPU and disks, CMS is moving toward controlled overflowing of jobs from sites that have data but are oversubscribed to others with spare CPU and network capacity, with those jobs accessing the data through real time Xrootd streaming over WAN. The major limiting factor for remote data access is the ability of the source storage system to serve such data, so the number of jobs accessing it must be carefully controlled. The CMS approach to this is to implement the overflowing by means of glideinWMS, a Condor based pilot system, and by providing the WMS w...

  4. Air Flows in Gravity Sewers - Determination of Wastewater Drag Coefficient

    DEFF Research Database (Denmark)

    Bentzen, Thomas Ruby; Østertoft, Kristian; Vollertsen, Jes

    2016-01-01

    of the study shows that by integrating the top/side wall shear stresses the log-law models for the air velocity distribution along the unwetted perimeter resulted in a good agreement with the friction forces calculated by use of the Colebrook-White formula for hydraulic smooth pipes. Secondly, the water......Several experiments have been conducted in order to improve the understanding of the wastewater drag and the wall frictional force acting on the headspace air in gravity sewers. The aim of the study is to improve the data basis for a numerical model of natural sewer ventilation. The results...... surface drags were found by log-law models of the velocity distribution in turbulent flows to fit velocity profiles measured from the water surface and by integrating the water surface drags along the wetted perimeter, mean water surface drags were found and a measure of the water surface drag coefficient...

  5. Regulatory control analysis and design for sewer systems

    DEFF Research Database (Denmark)

    Mollerup, Ane Loft; Mikkelsen, Peter Steen; Thornberg, Dines

    2015-01-01

    . To this end, four distinct modes of operation are identified (dry weather, filling, saturation and emptying) and for each of these the process gain matrix is found. Based on the gain matrices a controllability analysis is performed, to screen for suitable pairings between measurements and actuators......A systematic methodology for regulatory control analysis and design is adapted for sewer system operation and evaluated. The main challenge with adapting the methodology is the handling of the stochastic and transient nature of the rainfall disturbances, inherent to sewer system operation...... in the case study area of Copenhagen. The analysis effectively reduces the number of potential controlled variables, by considering the sensitivity of the measurements towards changes in the manipulated variables. Several potential pairings are generated and the best alternative is chosen for closed...

  6. Oxidation and Precipitation of Sulfide in Sewer Networks

    DEFF Research Database (Denmark)

    Nielsen, A. H.

    wastewater and biofilms of sewer networks was studied in detail with emphasis on determination of process kinetics and stoichiometry. In the water phase, sulfide oxidation may be both chemical and biological and the investigations showed that both processes were of significant importance in the sulfur cycle...... transformations. The experiments indicated that biological sulfide oxidation in the water phase and sulfide oxidation by sewer biofilms produce elemental sulfur under the conditions investigated. The stoichiometry of chemical sulfide oxidation was apparently more complex producing both thiosulfate and sulfate......-workers at Aalborg University for more than a decade. In the basic version, the WATS model simulates changes in dissolved oxygen (DO) and organic fractions of different biodegradability under both aerobic and anaerobic conditions. Evaluation of the model concept has demonstrated that it can be successfully...

  7. Aerobic and anaerobic transformations of sulfide in a sewer system--field study and model simulations.

    Science.gov (United States)

    Nielsen, Asbjørn Haaning; Vollertsen, Jes; Jensen, Henriette Stokbro; Madsen, Heidi Ina; Hvitved-Jacobsen, Thorkild

    2008-01-01

    The formation and fate of sulfide in a force main and a downstream-located gravity sewer were investigated in an extensive field study. Sulfide formation in the force main was significant. However, during 14 minutes of transport in the gravity sewer, the sulfide concentration decreased 30%, on average. An application of a conceptual sewer process model for simulating the formation and fate of sulfide was demonstrated. Overall, the model predicted that approximately 90% of the decrease of the sulfide concentration in the gravity sewer was the result of sulfide oxidation and that only a small fraction entered the sewer atmosphere, causing odor and corrosion. Even so, the model predicted concrete corrosion rates of up to 1.2 mm/y in the gravity sewer section.

  8. Life cycle assessment of urban wastewater systems: Quantifying the relative contribution of sewer systems.

    Science.gov (United States)

    Risch, Eva; Gutierrez, Oriol; Roux, Philippe; Boutin, Catherine; Corominas, Lluís

    2015-06-15

    This study aims to propose a holistic, life cycle assessment (LCA) of urban wastewater systems (UWS) based on a comprehensive inventory including detailed construction and operation of sewer systems and wastewater treatment plants (WWTPs). For the first time, the inventory of sewers infrastructure construction includes piping materials and aggregates, manholes, connections, civil works and road rehabilitation. The operation stage comprises energy consumption in pumping stations together with air emissions of methane and hydrogen sulphide, and water emissions from sewer leaks. Using a real case study, this LCA aims to quantify the contributions of sewer systems to the total environmental impacts of the UWS. The results show that the construction of sewer infrastructures has an environmental impact (on half of the 18 studied impact categories) larger than both the construction and operation of the WWTP. This study highlights the importance of including the construction and operation of sewer systems in the environmental assessment of centralised versus decentralised options for UWS.

  9. Model-based analysis of control performance in sewer systems

    DEFF Research Database (Denmark)

    Mollerup, Ane Høyer; Mauricio Iglesias, Miguel; Johansen, N.B.;

    2012-01-01

    Design and assessment of control in wastewater systems has to be tackled at all levels, including supervisory and regulatory level. We present here an integrated approach to assessment of control in sewer systems based on modelling and the use of process control tools to assess the controllability...... of the process. A case study of a subcatchment area in Copenhagen (Denmark) is used to illustrate the combined approach in modelling of the system and control assessment....

  10. South Davis Sewer District Pump Station Hydraulic Capacity Evaluation

    OpenAIRE

    Dixon, James W

    2011-01-01

    In 2010, South Davis Sewer District (SDSD) determined that possible hydraulic problems existed in their various pump stations operating within their treatment plants. A hydraulic analysis was conducted for the pump stations to diagnose the problems and provide possible alternative solutions. This analysis was conducted by using hydraulic minor loss equations to determine the amount of flow that the pumps were capable of producing and then comparing those results to the required demands in the...

  11. Worcester Municipal Separate Storm Sewer System (MS4) ...

    Science.gov (United States)

    2017-04-10

    Worcester was issued NPDES Permit MAS010002 for discharging storm water from its municipal separate storm sewer system (MS4) which became effective on October 30, 1998. The permit expired five years later on October 30, 2003; however, EPA administratively continued the permit as allowed by regulation. Proceeding to reissue this NPDES permit, EPA and MassDEP have now issued a draft permit and fact sheet (which provides EPA's technical basis for establishing permit conditions).

  12. Investigation of sewer exfiltration using integral pumping tests and wastewater indicators

    Science.gov (United States)

    Leschik, Sebastian; Musolff, Andreas; Martienssen, Marion; Krieg, Ronald; Bayer-Raich, Marti; Reinstorf, Frido; Strauch, Gerhard; Schirmer, Mario

    2009-11-01

    Leaky sewers affect urban groundwater by the exfiltration of untreated wastewater. However, the impact of sewer exfiltration on the groundwater is poorly understood. Most studies on sewer exfiltration focus on water exfiltration, but not on the impact on groundwater quality. In this paper we present a new monitoring approach to estimate mass flow rates Mex of different wastewater indicators (WWIs) from leaky sewers by applying integral pumping tests (IPTs). The problem of detecting and assessing heterogeneous concentrations in the vicinity of leaky sewers can be overcome with the IPT approach by the investigation of large groundwater volumes up- and downstream of leaky sewers. The increase in concentrations downstream of a leaky sewer section can be used to calculate Mex with a numerical groundwater model. The new monitoring approach was first applied using four IPT wells in Leipzig (Germany). Over a pumping period of five days we sampled five inorganic WWIs: B , Cl -, K +, NO 3-, NH 4+ and three xenobiotics: bisphenol-a, caffeine and tonalide. The resulting concentration-time series indicated an influence of wastewater at one IPT well downstream of the leaky sewer. We defined ranges of Mex by implementing the uncertainty of chemical analyses. The results showed a Mex of 0-10.9 g m - 1 d - 1 . The combination of Mex with wastewater concentrations from the target sewer yielded an exfiltration rate Qex of 28.0-63.9 L m - 1 d - 1 for the conservative ion Cl -. Most non-conservative WWIs showed reduced mass flow rates in the groundwater downstream of the leaky sewer that indicate a mass depletion during their passage from the sewer to the pumping well. Application of the IPT methodology at other field sites is possible. The IPT monitoring approach provides reliable Mex values that can help to assess the impact of leaky sewers on groundwater.

  13. Successful Municipal Separate Storm Sewer System Programs Implemented in the Navy - NESDI #494

    Science.gov (United States)

    2014-06-01

    2014 SUCCESSFUL MUNICIPAL SEPARATE STORM SEWER SYSTEM PROGRAMS IMPLEMENTED IN THE NAVY—NESDI #494 Prepared by: Edwin Chiang, P.E...SUBTITLE 5a. CONTRACT NUMBER SUCCESSFUL MUNICIPAL SEPARATE STORM SEWER SYSTEM PROGRAMS IMPLEMENTED IN THE NAVY—PROJECT #494 5b. GRANT NUMBER...installations as lessons learned for complying with municipal separate storm sewer system (MS4) regulatory requirements. An evaluation of business practices

  14. Long-term variations in Iceland–Scotland overflow strength during the Holocene

    Directory of Open Access Journals (Sweden)

    D. J. R. Thornalley

    2013-09-01

    Full Text Available The overflow of deep water from the Nordic seas into the North Atlantic plays a critical role in global ocean circulation and climate. Approximately half of this overflow occurs via the Iceland–Scotland (I–S overflow, yet the history of its strength throughout the Holocene (~ 0–11 700 yr ago, ka is poorly constrained, with previous studies presenting apparently contradictory evidence regarding its long-term variability. Here, we provide a comprehensive reconstruction of I–S overflow strength throughout the Holocene using sediment grain size data from a depth transect of 13 cores from the Iceland Basin. Our data are consistent with the hypothesis that the main axis of the I–S overflow on the Iceland slope was shallower during the early Holocene, deepening to its present depth by ~ 7 ka. Our results also reveal weaker I–S overflow during the early and late Holocene, with maximum overflow strength occurring at ~ 7 ka, the time of a regional climate thermal maximum. Climate model simulations suggest a shoaling of deep convection in the Nordic seas during the early and late Holocene, consistent with our evidence for weaker I–S overflow during these intervals. Whereas the reduction in I–S overflow strength during the early Holocene likely resulted from melting remnant glacial ice sheets, the decline throughout the last 7000 yr was caused by an orbitally induced increase in the amount of Arctic sea ice entering the Nordic seas. Although the flux of Arctic sea ice to the Nordic seas is expected to decrease throughout the next century, model simulations predict that under high emissions scenarios, competing effects, such as warmer sea surface temperatures in the Nordic seas, will result in reduced deep convection, likely driving a weaker I–S overflow.

  15. Performance Assessment of OVERFLOW on Distributed Computing Environment

    Science.gov (United States)

    Djomehri, M. Jahed; Rizk, Yehia M.

    2000-01-01

    The aerodynamic computer code, OVERFLOW, with a multi-zone overset grid feature, has been parallelized to enhance its performance on distributed and shared memory paradigms. Practical application benchmarks have been set to assess the efficiency of code's parallelism on high-performance architectures. The code's performance has also been experimented with in the context of the distributed computing paradigm on distant computer resources using the Information Power Grid (IPG) toolkit, Globus. Two parallel versions of the code, namely OVERFLOW-MPI and -MLP, have developed around the natural coarse grained parallelism inherent in a multi-zonal domain decomposition paradigm. The algorithm invokes a strategy that forms a number of groups, each consisting of a zone, a cluster of zones and/or a partition of a large zone. Each group can be thought of as a process with one or multithreads assigned to it and that all groups run in parallel. The -MPI version of the code uses explicit message-passing based on the standard MPI library for sending and receiving interzonal boundary data across processors. The -MLP version employs no message-passing paradigm; the boundary data is transferred through the shared memory. The -MPI code is suited for both distributed and shared memory architectures, while the -MLP code can only be used on shared memory platforms. The IPG applications are implemented by the -MPI code using the Globus toolkit. While a computational task is distributed across multiple computer resources, the parallelism can be explored on each resource alone. Performance studies are achieved with some practical aerodynamic problems with complex geometries, consisting of 2.5 up to 33 million grid points and a large number of zonal blocks. The computations were executed primarily on SGI Origin 2000 multiprocessors and on the Cray T3E. OVERFLOW's IPG applications are carried out on NASA homogeneous metacomputing machines located at three sites, Ames, Langley and Glenn. Plans

  16. Impact of water source management practices in residential areas on sewer networks - a review.

    Science.gov (United States)

    Marleni, N; Gray, S; Sharma, A; Burn, S; Muttil, N

    2012-01-01

    Prolonged drought which has occurred everywhere around the world has caused water shortages, leading many countries to consider more sustainable practices, which are called source management practices (SMPs) to ensure water availability for the future. SMPs include the practices of water use reduction, potable water substitution and wastewater volume reduction such as water demand management, rainwater harvesting, greywater recycling and sewer mining. Besides the well known advantages from SMPs, they also contribute to the alteration of wastewater characteristics which finally affect the process in downstream infrastructure such as sewerage networks. Several studies have shown that the implementation of SMPs decreases the wastewater flow, whilst increasing its strength. High-strength wastewater can cause sewer problems such as sewer blockage, odour and corrosion. Yet, not all SMPs and their impact on existing sewer networks have been investigated. Therefore, this study reviews some examples of four common SMPs, the wastewater characteristics and the physical and biochemical transformation processes in sewers and the problems that might caused by them, and finally the potential impacts of those SMPs on wastewater characteristics and sewer networks are discussed. This paper provides sewer system managers with an overview of potential impacts on the sewer network due to the implementation of some SMPs. Potential research opportunities for the impact of SMPs on existing sewers are also identified.

  17. Atmospheric forcing of salinity in the overflow of Denmark Strait

    Directory of Open Access Journals (Sweden)

    J. Holfort

    2007-09-01

    Full Text Available The temporal evolution of the characteristics of Denmark Strait Overflow Water (DSOW is reconstructed using hydrographic data and compared with possible atmospheric forcing mechanisms. It is concluded that the main factor influencing the DSOW characteristics at a time scale of one to several years is the difference in mean sea level pressure across Denmark Strait or, in other words, the wind along Denmark Strait. At these time scales upstream changes in the characteristics of the different water masses involved in the formation of DSOW are only of minor importance. The main process responsible for the observed salinity changes in the DSOW is mixing in Denmark Strait. Triggered by the wind, different water masses contribute with changing amounts to the formation of DSOW, leading to the observed changes in the salinity of DSOW.

  18. Performance Modeling for Heterogeneous Wireless Networks with Multiservice Overflow Traffic

    DEFF Research Database (Denmark)

    Huang, Qian; Ko, King-Tim; Iversen, Villy Bæk

    2009-01-01

    Performance modeling is important for the purpose of developing efficient dimensioning tools for large complicated networks. But it is difficult to achieve in heterogeneous wireless networks, where different networks have different statistical characteristics in service and traffic models....... Multiservice loss analysis based on multi-dimensional Markov chain becomes intractable in these networks due to intensive computations required. This paper focuses on performance modeling for heterogeneous wireless networks based on a hierarchical overlay infrastructure. A method based on decomposition...... of the correlated traffic is used to achieve an approximate performance modeling for multiservice in hierarchical heterogeneous wireless networks with overflow traffic. The accuracy of the approximate performance obtained by our proposed modeling is verified by simulations....

  19. [Sanitary regulation in Mexico and the Free Trade Treaty].

    Science.gov (United States)

    Juan-López, M

    1994-01-01

    In this paper are discussed essential issues about the concept, characteristics and general functions of sanitary regulation, as well as the principles and main lines of action contained in the Program of Modernization of the Sanitary Regulation, which is being implemented by the Ministry of Health of Mexico. In addition, some considerations are offered regarding the supporting role of such a program, in the context of the free trade era that Mexico is undergoing. After 40 years of an outdated sanitary regulation based in a non-functional licensing concept, the new and improved scheme relies on several ammendments to the General Health Law. Thus, the present approach, focuses on a set of flexible, simple and efficient rules, strengthened by proven scientific and technical procedures.

  20. Sanitary Landfill Groundwater Monitoring Report. Second Quarter 1995

    Energy Technology Data Exchange (ETDEWEB)

    Chase, J.A.

    1995-08-01

    This report contains analytical data for samples taken during second quarter 1995 from wells of the LFW series located at the Sanitary Landfill at the Savannah River Site (SRS). The data are submitted in reference to the Sanitary landfill Operating Permit (DWP-087A). The report presents monitoring results that equaled or exceeded the Safe Drinking Water Act final Primary Water Standards (PDWS) or screening levels, established by the US Environmental Protection Agency (Appendix A), the South Carolina final Primary Drinking Water Standard for lead (Appendix A), or the SRS flagging criteria (Appendix B).

  1. PROPOSAL OF SANITARY MANAGEMENT OF EDIBLE ECHINODERMS IN SARDINIA

    Directory of Open Access Journals (Sweden)

    G. Terrosu

    2011-01-01

    Full Text Available Sea urchin (Paracentrotus lividus is an edible echinoderm very common in the Mediterranean sea. In the Sardinian gastronomic tradition it represents a product very used in some periods of the year, but in practice the sanitary controls by the competent authorities are very difficult. The Reg. (EC n. 853/2004 provides that, as regards as the control on production, echinoderms are assimilable to live bivalve molluscs, with the exception of the provisions on purification. In this work a proposal for the sanitary management of the phases of gathering, transport and selling of the sea urchins has been studied.

  2. Sanitary Transportation of Human and Animal Food. Final rule.

    Science.gov (United States)

    2016-04-06

    The Food and Drug Administration (FDA or we) is issuing a final rule to establish requirements for shippers, loaders, carriers by motor vehicle and rail vehicle, and receivers engaged in the transportation of food, including food for animals, to use sanitary transportation practices to ensure the safety of the food they transport. This action is part of our larger effort to focus on prevention of food safety problems throughout the food chain and is part of our implementation of the Sanitary Food Transportation Act of 2005 (2005 SFTA) and the Food Safety Modernization Act of 2011 (FSMA).

  3. Sanitary Landfill groundwater monitoring report. First quarter 1993

    Energy Technology Data Exchange (ETDEWEB)

    1993-05-01

    This report contains analytical data for samples taken during first quarter 1993 from wells of the LFW series located at the Sanitary Landfill at the Savannah River Site. The data are submitted in reference to the Sanitary Landfill Operating Permit (DWP-087A). The report presents monitoring results that equaled or exceeded the Safe Drinking Water Act final Primary Drinking Water Standards (PDWS) or screening levels, established by the US Environmental Protection Agency, the South Carolina final Primary Drinking Water Standards for lead or the SRS flagging criteria.

  4. Sanitary landfill groundwater monitoring report, Third Quarter 1999

    Energy Technology Data Exchange (ETDEWEB)

    Chase, J.

    1999-12-08

    This report contains analytical data for samples taken during Third Quarter 1999 from wells of the LFW series located at the Sanitary Landfill at the Savannah River Site. The data are submitted in reference to the Sanitary Landfill Operating Permit. The report presents monitoring results that equaled or exceeded the Safe Drinking Water Act final Primary Drinking Water Standards or screening levels, established by the U.S. Environmental Protection Agency, the South Carolina final Primary Drinking Water Standard for lead, or the SRS flagging criteria.

  5. Association between Gastrointestinal Illness and Precipitation in Areas Impacted by Combined Sewer Systems: Utilizing a Distributed Lag Model

    Science.gov (United States)

    Combined sewer systems collect rainwater runoff, sewage, and industrial wastewater for transit to treatment facilities. With heavy precipitation, volumes can exceed capacity of treatment facilities, and wastewater discharges directly to receiving waters. These combined sewer over...

  6. Watershed Scale Impacts of Stormwater Green Infrastructure on Hydrology, Nitrogen Fluxes, and Combined Sewer Overflows in the Baltimore, MD and Washington, DC area

    Science.gov (United States)

    Despite the increasing use of urban stormwater green infrastructure (SGI), including detention ponds and rain gardens, few studies have quantified the cumulative effects of multiple SGI projects on hydrology and water quality at the watershed scale. To assess the effects of SGI, ...

  7. EPA ORD/EPA REGION 2/PITTSBURGH WSA COOPERATIVE EFFORT: EVALUATING CRYPTOSPORIDIUM AND GIARDIA IN COMBINED SEWER OVERFLOW AS A THREAT TO DRINKING WATER SUPPLIES

    Science.gov (United States)

    Since the first identified Cryptosporidium outbreak in the United Kingdom in 1983, emerging protozoa pathogens Cryptosporidium and Giardia have become the subject of growing local, state, and national concerns. Both organisms have been the causative agent of many gastrointestina...

  8. Citizen science-based water quality monitoring: Constructing a large database to characterize the impacts of combined sewer overflow in New York City.

    Science.gov (United States)

    Farnham, David J; Gibson, Rebecca A; Hsueh, Diana Y; McGillis, Wade R; Culligan, Patricia J; Zain, Nina; Buchanan, Rob

    2017-02-15

    To protect recreational water users from waterborne pathogen exposure, it is crucial that waterways are monitored for the presence of harmful bacteria. In NYC, a citizen science campaign is monitoring waterways impacted by inputs of storm water and untreated sewage during periods of rainfall. However, the spatial and temporal scales over which the monitoring program can sample are constrained by cost and time, thus hindering the construction of databases that benefit both scientists and citizens. In this study, we first illustrate the scientific value of a citizen scientist monitoring campaign by using the data collected through the campaign to characterize the seasonal variability of sampled bacterial concentration as well as its response to antecedent rainfall. Second, we examine the efficacy of the HyServe Compact Dry ETC method, a lower cost and time-efficient alternative to the EPA-approved IDEXX Enterolert method for fecal indicator monitoring, through a paired sample comparison of IDEXX and HyServe (total of 424 paired samples). The HyServe and IDEXX methods return the same result for over 80% of the samples with regard to whether a water sample is above or below the EPA's recreational water quality criteria for a single sample of 110 enterococci per 100mL. The HyServe method classified as unsafe 90% of the 119 water samples that were classified as having unsafe enterococci concentrations by the more established IDEXX method. This study seeks to encourage other scientists to engage with citizen scientist communities and to also pursue the development of cost- and time-efficient methodologies to sample environmental variables that are not easily collected or analyzed in an automated manner. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Watershed Scale Impacts of Stormwater Green Infrastructure on Hydrology, Nitrogen Fluxes, and Combined Sewer Overflows in the Baltimore, MD and Washington, DC area

    Science.gov (United States)

    Despite the increasing use of urban stormwater green infrastructure (SGI), including detention ponds and rain gardens, few studies have quantified the cumulative effects of multiple SGI projects on hydrology and water quality at the watershed scale. To assess the effects of SGI, ...

  10. Process of Levee Breach by Overflow at the Full Scale Chiyoda Experimental Channel

    Science.gov (United States)

    Shimada, T.; Yokoyama, H.

    2011-12-01

    The increased occurrence of storm disasters caused by typhoons and local downpours in recent years has given rise to concerns over the possibility of large-scale floods resulting from river overflow. Levee breaches cause particularly severe damage, and in Japan, more than 80% of such accidents in the past have been attributed to overflow. Previous studies on overflow-induced levee breaches have not revealed the mechanisms of these issues on a full-scale 3D basis (i.e., side-overflow taking river flow on the riverside land into consideration). It is important to clarify these mechanisms in terms of disaster prevention and for the purpose of bringing progress in future studies on overflow-induced failure. Levees (levee crown width is 3m in 2010 and 6m in 2011, levee height is 3m, levee length is 80m) were built in the Chiyoda Experimental Channel (full-scale experimental channel; width is 30m, length is 1,300m, maximum discharge is 170t/s) in Hokkaido Japan, and a three-dimensional experiment on levee breach by overflow. The findings of the experiment are as follows: After the beginning of overflow, levee breach widening did not begin until after most of the levee section had collapsed. And in case of 6m of the levee crown width, that time in becomes long. It was also considered that, even if overflow occurred, extremely serious damage (e.g., sudden increase in levee breach width and overflow discharge) was unlikely unless the majority of the levee section collapsed.

  11. A neuromorphic model of motor overflow in focal hand dystonia due to correlated sensory input

    Science.gov (United States)

    Sohn, Won Joon; Niu, Chuanxin M.; Sanger, Terence D.

    2016-10-01

    Objective. Motor overflow is a common and frustrating symptom of dystonia, manifested as unintentional muscle contraction that occurs during an intended voluntary movement. Although it is suspected that motor overflow is due to cortical disorganization in some types of dystonia (e.g. focal hand dystonia), it remains elusive which mechanisms could initiate and, more importantly, perpetuate motor overflow. We hypothesize that distinct motor elements have low risk of motor overflow if their sensory inputs remain statistically independent. But when provided with correlated sensory inputs, pre-existing crosstalk among sensory projections will grow under spike-timing-dependent-plasticity (STDP) and eventually produce irreversible motor overflow. Approach. We emulated a simplified neuromuscular system comprising two anatomically distinct digital muscles innervated by two layers of spiking neurons with STDP. The synaptic connections between layers included crosstalk connections. The input neurons received either independent or correlated sensory drive during 4 days of continuous excitation. The emulation is critically enabled and accelerated by our neuromorphic hardware created in previous work. Main results. When driven by correlated sensory inputs, the crosstalk synapses gained weight and produced prominent motor overflow; the growth of crosstalk synapses resulted in enlarged sensory representation reflecting cortical reorganization. The overflow failed to recede when the inputs resumed their original uncorrelated statistics. In the control group, no motor overflow was observed. Significance. Although our model is a highly simplified and limited representation of the human sensorimotor system, it allows us to explain how correlated sensory input to anatomically distinct muscles is by itself sufficient to cause persistent and irreversible motor overflow. Further studies are needed to locate the source of correlation in sensory input.

  12. Characteristics of the Nordic Seas overflows in a set of Norwegian Earth System Model experiments

    Science.gov (United States)

    Guo, Chuncheng; Ilicak, Mehmet; Bentsen, Mats; Fer, Ilker

    2016-08-01

    Global ocean models with an isopycnic vertical coordinate are advantageous in representing overflows, as they do not suffer from topography-induced spurious numerical mixing commonly seen in geopotential coordinate models. In this paper, we present a quantitative diagnosis of the Nordic Seas overflows in four configurations of the Norwegian Earth System Model (NorESM) family that features an isopycnic ocean model. For intercomparison, two coupled ocean-sea ice and two fully coupled (atmosphere-land-ocean-sea ice) experiments are considered. Each pair consists of a (non-eddying) 1° and a (eddy-permitting) 1/4° horizontal resolution ocean model. In all experiments, overflow waters remain dense and descend to the deep basins, entraining ambient water en route. Results from the 1/4° pair show similar behavior in the overflows, whereas the 1° pair show distinct differences, including temperature/salinity properties, volume transport (Q), and large scale features such as the strength of the Atlantic Meridional Overturning Circulation (AMOC). The volume transport of the overflows and degree of entrainment are underestimated in the 1° experiments, whereas in the 1/4° experiments, there is a two-fold downstream increase in Q, which matches observations well. In contrast to the 1/4° experiments, the coarse 1° experiments do not capture the inclined isopycnals of the overflows or the western boundary current off the Flemish Cap. In all experiments, the pathway of the Iceland-Scotland Overflow Water is misrepresented: a major fraction of the overflow proceeds southward into the West European Basin, instead of turning westward into the Irminger Sea. This discrepancy is attributed to excessive production of Labrador Sea Water in the model. The mean state and variability of the Nordic Seas overflows have significant consequences on the response of the AMOC, hence their correct representations are of vital importance in global ocean and climate modelling.

  13. Long-term variations in Iceland–Scotland overflow strength during the Holocene

    Directory of Open Access Journals (Sweden)

    D. J. R. Thornalley

    2013-03-01

    Full Text Available The overflow of deep water from the Nordic Seas into the North Atlantic plays a critical role in global ocean circulation and climate. Approximately half of this overflow occurs via the Iceland–Scotland (I–S overflow, yet the history of its strength throughout the Holocene (~0–11 700 yr ago, ka is poorly constrained, with previous studies presenting apparently contradictory evidence regarding its long-term variability. Here, we provide a comprehensive reconstruction of I–S overflow strength throughout the Holocene using sediment grain size data from a depth transect of 13 cores from the Iceland basin. Our results reveal weaker I–S overflow during the early and late Holocene, with maximum overflow strength occurring at ~7 ka, the time of a regional climate thermal maximum. Climate model simulations suggest a shoaling of deep convection in the Nordic Seas during the early and late Holocene, consistent with our evidence for weaker I–S overflow during these intervals. Whereas the reduction in I–S overflow strength during the early Holocene likely resulted from melting remnant glacial ice-sheets, the decline throughout the last 7000 yr was caused by an orbitally-induced increase in the amount of Arctic sea-ice entering the Nordic Seas. Although the flux of Arctic sea-ice to the Nordic Seas is expected to decrease throughout the next century, model simulations predict that under high emissions scenarios, competing effects, such as warmer sea surface temperatures in the Nordic Seas, will result in reduced deep convection, likely driving a weaker I–S overflow.

  14. Leveraging existing infrastructure for central automatic control of multiple sewer systems

    NARCIS (Netherlands)

    Van Loenen, A.; Van Heeringen, K.J.; Van Nooyen, R.R.P.; Van Velzen, E.

    2012-01-01

    In this paper we discuss a project in which water quality improvements of surface waters are gained by upgrading locally controlled sewer systems. The paper focuses on the reuse and extension of existing sewer systems and hardware and software infrastructure in an experimental integrated automatic

  15. Growth kinetics of hydrogen sulfide oxidizing bacteria in corroded concrete from sewers

    NARCIS (Netherlands)

    Jensen, H.S.; Lens, P.N.L.; Nielsen, J.L.; Bester, K.; Nielsen, A.H.; Hvitved-Jacobsen, Th.; Vollertsen, J.

    2011-01-01

    Hydrogen sulfide oxidation by microbes present on concrete surfaces of sewer pipes is a key process in sewer corrosion. The growth of aerobic sulfur oxidizing bacteria from corroded concrete surfaces was studied in a batch reactor. Samples of corrosion products, containing sulfur oxidizing bacteria,

  16. Unstable Roche-Lobe Overflow of Gaseous Planets

    Science.gov (United States)

    Jackson, Brian

    The discoveries of more than 100 roughly Earth-sized bodies with orbital periods less than 1 day, ultra-short-period planets or candidates (USPs), have challenged planet formation theories, and evidence suggests USPs may be the remnants of gaseous planets that shed their atmospheres. Indeed, many hot Jupiters are near Roche-Lobe overflow (RLO), and tidal decay can push them the rest of the way in. Recent work has shown stable RLO (atmospheres lost via a steady outflow and thin accretion disk) probably cannot produce USPs on its own but suggested unstable RLO (atmospheres quickly shed on dynamical timescales) may. In fact, stable RLO may drive overflowing hot Jupiters into unstable RLO, and by analogy with the common-envelope binaries, the core that remains can drive off the gaseous envelope at the cost of its orbital energy. Wellestablished mass-radius relations for gaseous planets, coupled to simple energy and angular momentum considerations, provide a connection between the observed masses and periods for USPs and their putative progenitor gaseous planets, with few free parameters. We propose to investigate the hypothesis that USPs originate through tidal decay and a combination of stable and unstable Roche-lobe overflow of short-period gaseous planets through the following studies: -We will explore the planetary masses, orbital periods, etc. that produce unstable RLO using the Modules for Experiments in Stellar Astrophysics (MESA) suite. -We will relate the observed periods and masses of USPs to their putative progenitor masses and periods to see whether they are consistent with the unstable RLO hypothesis. This proposal is directly relevant to the Exoplanets Research Program since it seeks to "understand the ... physical processes of exoplanets" and "improve understanding of [their] origins" through "theoretical studies ... and modeling'". We also expect that it will have broad impacts on a variety of astrophysical topics: -Ultra-short period planets could

  17. International training seminar: high training on sanitary landfills design, Madrid 7-11, April 1997

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-09-01

    The seminar on design of sanitary landfills was articulated in 5 sessions: 1.- Design of sanitary landfills depending on the quality of wastes. 2.- Legal, techniques and administrative aspects of management. 3.- Geotechniques studies 4.- Biogas 5.- Environmental impact of sanitary landfills.

  18. Conducting Sanitary Surveys of Water Supply Systems. Student Workbook.

    Science.gov (United States)

    1976

    This workbook is utilized in connection with a 40-hour course on sanitary surveys of water supply systems for biologists, chemists, and engineers with experience as a water supply evaluator. Practical training is provided in each of the 21 self-contained modules. Each module outlines the purpose, objectives and content for that section. The course…

  19. 30 CFR 75.1712-10 - Underground sanitary facilities; maintenance.

    Science.gov (United States)

    2010-07-01

    ... a clean and sanitary condition. Holding tanks shall be serviced and cleaned when full and in no case... recharging. Transfer tanks and transfer equipment used underground shall be equipped with suitable fittings to permit complete drainage of holding tanks without spillage and allow for the...

  20. [Ways of urban sanitary and epidemiological well-being management].

    Science.gov (United States)

    Kreĭmer, M A

    2010-01-01

    The scientific rationale for preventive measures based on sanitary-and-epidemiological surveillance on environmental objects is considered. The sizes of functional zones and space for various types of communal services and amenities and leisure are regulated to ensure good urban vital activities. Multistorey housing causes an increase in the number of negative factors per area units and in their impact on health. A proposal has been made for the standardization of the ranges of urban population upsurge and size, by using the sanitary-and-hygienic rules and norms rather than climatic parameters. A criterion system for assessing the data of statistical observations has been substantiated and 5 levels of analysis and managerial decision-making have been proposed. Cause-and-effect relations may be determined for the parameters of the second level; models of program-oriented studies for the third level, only sanitary-and-epidemiological surveillance is possible for the fourth and fifth levels. The space planning scheme must provide for water supply reserves, generation areas for pure air coming into the town, and waste disposal areas. The general layout may use statistical observation parameters characterizing the second level of occurrence of negative phenomena. The statistical observation parameters characterizing the third and fourth levels of occurrence of negative phenomena may be used for municipal improvements and sanitary maintenance. These characterizing the fourth and fifth level may be used for prevention in therapeutic-and-prophylactic institutions.

  1. Interim Sanitary Landfill Groundwater Monitoring Report (1998 Annual Report)

    Energy Technology Data Exchange (ETDEWEB)

    Wells, D.

    1999-03-18

    The SRS Interim Sanitary Landfill opened in Mid-1992 and operated until 1998 under Domestic Waste Permit No. 025500-1120. Several contaminants have been detected in the groundwater beneath the unit.The well sampling and analyses were conducted in accordance with Procedure 3Q5, Hydrogeologic Data Collection.

  2. 21 CFR 110.37 - Sanitary facilities and controls.

    Science.gov (United States)

    2010-04-01

    ...) FOOD FOR HUMAN CONSUMPTION CURRENT GOOD MANUFACTURING PRACTICE IN MANUFACTURING, PACKING, OR HOLDING HUMAN FOOD Buildings and Facilities § 110.37 Sanitary facilities and controls. Each plant shall be... water to required locations throughout the plant. (2) Properly convey sewage and liquid disposable waste...

  3. Flooding in urban drainage systems: Coupling hyperbolic conservation laws for sewer systems and surface flow

    CERN Document Server

    Borsche, Raul

    2014-01-01

    In this paper we propose a model for a sewer network coupled to surface flow and investigate it numerically. In particular, we present a new model for the manholes in storm sewer systems. It is derived using the balance of the total energy in the complete network. The resulting system of equations contains, aside from hyperbolic conservation laws for the sewer network and algebraic relations for the coupling conditions, a system of ODEs governing the flow in the manholes. The manholes provide natural points for the interaction of the sewer system and the run off on the urban surface modelled by shallow water equations. Finally, a numerical method for the coupled system is presented. In several numerical tests we study the influence of the manhole model on the sewer system and the coupling with 2D surface flow.

  4. Prioritizing sewer rehabilitation projects using AHP-PROMETHEE II ranking method.

    Science.gov (United States)

    Kessili, Abdelhak; Benmamar, Saadia

    2016-01-01

    The aim of this paper is to develop a methodology for the prioritization of sewer rehabilitation projects for Algiers (Algeria) sewer networks to support the National Sanitation Office in its challenge to make decisions on prioritization of sewer rehabilitation projects. The methodology applies multiple-criteria decision making. The study includes 47 projects (collectors) and 12 criteria to evaluate them. These criteria represent the different issues considered in the prioritization of the projects, which are structural, hydraulic, environmental, financial, social and technical. The analytic hierarchy process (AHP) is used to determine weights of the criteria and the Preference Ranking Organization Method for Enrichment Evaluations (PROMETHEE II) method is used to obtain the final ranking of the projects. The model was verified using the sewer data of Algiers. The results have shown that the method can be used for prioritizing sewer rehabilitation projects.

  5. Simulation of sulfide buildup in wastewater and atmosphere of sewer networks.

    Science.gov (United States)

    Nielsen, A H; Yongsiri, C; Hvitved-Jacobsen, T; Vollertsen, J

    2005-01-01

    A model concept for prediction of sulfide buildup in sewer networks is presented. The model concept is an extension to--and a further development of--the WATS model (Wastewater Aerobic-anaerobic Transformations in Sewers), which has been developed by Hvitved-Jacobsen and co-workers at Aalborg University. In addition to the sulfur cycle, the WATS model simulates changes in dissolved oxygen and carbon fractions of different biodegradability. The sulfur cycle was introduced via six processes: 1. sulfide production taking place in the biofilm covering the permanently wetted sewer walls; 2. biological sulfide oxidation in the permanently wetted biofilm; 3. chemical and biological sulfide oxidation in the water phase; 4. sulfide precipitation with metals present in the wastewater; 5. emission of hydrogen sulfide to the sewer atmosphere and 6. adsorption and oxidation of hydrogen sulfide on the moist sewer walls where concrete corrosion may take place.

  6. Level II contaminant investigation of Overflow National Wildlife Refuge, Wilmot, Arkansas

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Conductivity and turbidity exhibited the greatest variation of the water quality parameters measured at Overflow NWR and the proposed acquisition land (Table 2)....

  7. An Evaluation of Felsenthal and Overflow National Wildlife Refuge's Forest Habitat Management Program's : Review Team Report

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The report describes and evaluates Felsenthal and Overflow NWR's forest habitat management practices. Topics include general refuge information, silviculture...

  8. Mobile Acoustical Bat Monitoring Annual Summary Report CY 2013 to 2016 - Overflow National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — These reports summarize bat calls collected along transects at Overflow NWR between 2013 and 2015. Calls were classified using Bat Call ID ([BCID] version 2.5a)...

  9. Laboratory Investigation of Entrainment and Mixing in Oceanic Overflows

    CERN Document Server

    Philippe, Odier; Ecke, Robert E

    2013-01-01

    We present experimental measurements of a wall-bounded gravity current, motivated by characterizing natural gravity currents such as oceanic overflows. We use particle image velocimetry and planar laser-induced fluorescence to simultaneously measure the velocity and density fields as they evolve downstream of the initial injection from a turbulent channel flow onto a plane inclined at 10$^\\circ$ with respect to horizontal. The turbulence level of the input flow is controlled by injecting velocity fluctuations upstream of the output nozzle. The initial Reynolds number based on Taylor microscale of the flow, R$_\\lambda$, is varied between 40 and 120, and the effects of the initial turbulence level are assessed. The bulk Richardson number $Ri$ for the flow is about 0.3 whereas the gradient Richardson number $Ri_g$ varies between 0.04 and 0.25, indicating that shear dominates the stabilizing effect of stratification. Kelvin-Helmholtz instability results in vigorous vertical transport of mass and momentum. We pres...

  10. Hot-Jupiter Core Mass from Roche-lobe Overflow

    CERN Document Server

    Ginzburg, Sivan

    2016-01-01

    The orbits of many observed hot Jupiters are decaying rapidly due to tidal interaction, eventually reaching the Roche limit. We analytically study the ensuing coupled mass loss and orbital evolution during the Roche-lobe overflow and find two possible scenarios. Planets with light cores $M_c\\lesssim 6M_\\oplus$ (assuming a nominal tidal dissipation factor $Q\\sim 10^6$ for the host star) are transformed into Neptune-mass gas planets, orbiting at a separation (relative to the stellar radius) $a/R_\\star\\approx 3.5$. Planets with heavier cores $M_c\\gtrsim 6M_\\oplus$ plunge rapidly until they are destroyed at the stellar surface. Remnant gas-Neptunes, which are stable to photo-evaporation, are absent from the observations, despite their unique transit radius ($5-10R_\\oplus$). This result suggests that $M_c\\gtrsim 6M_\\oplus$, providing a useful constraint on the poorly-known core mass that may distinguish between different formation theories of gas giants. Alternatively, given a prior estimate of $M_c\\approx 6 M_\\op...

  11. Implementation of Preconditioned Dual-Time Procedures in OVERFLOW

    Science.gov (United States)

    Pandya, Shishir A.; Venkateswaran, Sankaran; Pulliam, Thomas H.; Kwak, Dochan (Technical Monitor)

    2003-01-01

    Preconditioning methods have become the method of choice for the solution of flowfields involving the simultaneous presence of low Mach and transonic regions. It is well known that these methods are important for insuring accurate numerical discretization as well as convergence efficiency over various operating conditions such as low Mach number, low Reynolds number and high Strouhal numbers. For unsteady problems, the preconditioning is introduced within a dual-time framework wherein the physical time-derivatives are used to march the unsteady equations and the preconditioned time-derivatives are used for purposes of numerical discretization and iterative solution. In this paper, we describe the implementation of the preconditioned dual-time methodology in the OVERFLOW code. To demonstrate the performance of the method, we employ both simple and practical unsteady flowfields, including vortex propagation in a low Mach number flow, flowfield of an impulsively started plate (Stokes' first problem) arid a cylindrical jet in a low Mach number crossflow with ground effect. All the results demonstrate that the preconditioning algorithm is responsible for improvements to both numerical accuracy and convergence efficiency and, thereby, enables low Mach number unsteady computations to be performed at a fraction of the cost of traditional time-marching methods.

  12. On the other hand: overflow movements of infants' hands and legs during unimanual object exploration.

    Science.gov (United States)

    Soska, Kasey C; Galeon, Margaret A; Adolph, Karen E

    2012-05-01

    Motor overflow is extraneous movement in a limb not involved in a motor action. Typically, overflow is observed in people with neurological impairments and in healthy children and adults during strenuous and attention-demanding tasks. In the current study, we found that young infants produce vast amounts of motor overflow, corroborating claims of symmetry being the default state of the motor system. While manipulating an object with one hand, all 27 of the typically developing 4.5- to 7.5-month-old infants who we observed displayed overflow movements of the free hand (on 4/5 of unimanual actions). Mirror-image movements of the hands occurred on 1/8 of unimanual actions, and the hands and legs moved in synchrony on 1/3 of unimanual acts. Motor overflow was less frequent when infants were in a sitting posture and when infants watched their acting hand, suggesting that upright posture and visual examination may help to alleviate overflow and break obligatory symmetry in healthy infants.

  13. Urban flood risk assessment using sewer flooding databases.

    Science.gov (United States)

    Caradot, Nicolas; Granger, Damien; Chapgier, Jean; Cherqui, Frédéric; Chocat, Bernard

    2011-01-01

    Sustainable water management is a global challenge for the 21st century. One key aspect remains protection against urban flooding. The main objective is to ensure or maintain an adequate level of service for all inhabitants. However, level of service is still difficult to assess and the high-risk locations difficult to identify. In this article, we propose a methodology, which (i) allows water managers to measure the service provided by the urban drainage system with regard to protection against urban flooding; and (ii) helps stakeholders to determine effective strategies for improving the service provided. One key aspect of this work is to use a database of sewer flood event records to assess flood risk. Our methodology helps urban water managers to assess the risk of sewer flooding; this approach does not seek to predict flooding but rather to inform decision makers on the current level of risk and on actions which need to be taken to reduce the risk. This work is based on a comprehensive definition of risk, including territorial vulnerability and perceptions of urban water stakeholders. This paper presents the results and the methodological contributions from implementing the methodology on two case studies: the cities of Lyon and Mulhouse.

  14. Modeling Sulfides, pH and Hydrogen Sulfide Gas in the Sewers of San Francisco.

    Science.gov (United States)

    Vollertsen, Jes; Revilla, Nohemy; Hvitved-Jacobsen, Thorkild; Nielsen, Asbjørn Haaning

    2015-11-01

    An extensive measuring campaign targeted on sewer odor problems was undertaken in San Francisco. It was assessed whether a conceptual sewer process model could reproduce the measured concentrations of total sulfide in the wastewater and H2S gas in the sewer atmosphere, and to which degree such simulations have potential for further improving odor and sulfide management. The campaign covered measurement of wastewater sulfide by grab sampling and diurnal sampling, and H2S gas in the sewer atmosphere was logged. The tested model was based on the Wastewater Aerobic/Anaerobic Transformations in Sewers (WATS) sewer process concept, which never had been calibrated to such an extensive dataset. The study showed that the model was capable of reproducing the general levels of wastewater sulfide, wastewater pH, and sewer H2S gas. It could also reproduce the general variability of these parameters, albeit with some uncertainty. It was concluded that the model could be applied for the purpose in mind.

  15. The Ecology of Acidophilic Microorganisms in the Corroding Concrete Sewer Environment.

    Science.gov (United States)

    Li, Xuan; Kappler, Ulrike; Jiang, Guangming; Bond, Philip L

    2017-01-01

    Concrete corrosion is one of the most significant problems affecting valuable sewer infrastructure on a global scale. This problem occurs in the aerobic zone of the sewer, where a layer of surface corrosion develops on the exposed concrete and the surface pH is typically lowered from around 11-10 (pristine concrete) to pH 2-4. Acidophilic microorganisms become established as biofilms within the concrete corrosion layer and enhance the loss of concrete mass. Until recently, the acidophilic community was considered to comprise relatively few species of microorganisms, however, the biodiversity of the corrosion community is now recognized as being extensive and varying from different sewer environmental conditions. The diversity of acidophiles in the corrosion communities includes chemolithoautotrophs, chemolithoheterotrophs, and chemoorganoheterotrophs. The activity of these microorganisms is strongly affected by H2S levels in the sewer gas phase, although CO2, organic matter, and iron in the corrosion layer influence this acidic ecosystem. This paper briefly presents the conditions within the sewer that lead to the development of concrete corrosion in that environment. The review focuses on the acidophilic microorganisms detected in sewer corrosion environments, and then summarizes their proposed functions and physiology, especially in relation to the corrosion process. To our knowledge, this is the first review of acidophilic corrosion microbial communities, in which, the ecology and the environmental conditions (when available) are considered. Ecological studies of sewer corrosion are limited, however, where possible, we summarize the important metabolic functions of the different acidophilic species detected in sewer concrete corrosion layers. It is evident that microbial functions in the acidic sewer corrosion environment can be linked to those occurring in the analogous acidic environments of acid mine drainage and bioleaching.

  16. Stream restoration and sanitary infrastructure alter sources and fluxes of water, carbon, and nutrients in urban watersheds

    Directory of Open Access Journals (Sweden)

    M. J. Pennino

    2015-12-01

    Full Text Available An improved understanding of sources and timing of water and nutrient fluxes associated with urban stream restoration is critical for guiding effective watershed management. We investigated how sources, fluxes, and flowpaths of water, carbon (C, nitrogen (N, and phosphorus (P shift in response to differences in stream restoration and sanitary infrastructure. We compared a restored stream with 3 unrestored streams draining urban development and stormwater management over a 3 year period. We found that there was significantly decreased peak discharge in response to precipitation events following stream restoration. Similarly, we found that the restored stream showed significantly lower monthly peak runoff (9.4 ± 1.0 mm d−1 compared with two urban unrestored streams (ranging from 44.9 ± 4.5 to 55.4 ± 5.8 mm d−1 draining higher impervious surface cover. Peak runoff in the restored stream was more similar to a less developed stream draining extensive stormwater management (13.2 ± 1.9 mm d−1. Interestingly, the restored stream exported most carbon, nitrogen, and phosphorus loads at relatively lower streamflow than the 2 more urban streams, which exported most of their loads at higher and less frequent streamflow. Annual exports of total carbon (6.6 ± 0.5 kg ha−1 yr−1, total nitrogen (4.5 ± 0.3 kg ha−1 yr−1, and total phosphorus (161 ± 15 g ha−1 yr−1 were significantly lower in the restored stream compared to both urban unrestored streams (p < 0.05 and similar to the stream draining stormwater management. Although stream restoration appeared to potentially influence hydrology to some degree, nitrate isotope data suggested that 55 ± 1 % of the nitrate in the restored stream was derived from leaky sanitary sewers (during baseflow, similar to the unrestored streams. Longitudinal synoptic surveys of water and nitrate isotopes along all 4 watersheds suggested the importance of urban groundwater contamination from leaky piped

  17. Principles and approaches for numerical modelling of sediment transport in sewers

    DEFF Research Database (Denmark)

    Mark, Ole; Larsen, Torben; Appelgren, Cecilia

    1994-01-01

    A study has been carried out at the University of Aalborg, Denmark and VBB VIAK, Sweden with the objectives to describe the effect of sediment deposits on the hydraulic capacity of sewer systems and to investigate the sediment transport in sewer systems. A results of the study is a mathematical...... model MOUSE ST which describes the sediment transport in sewers. This paper discusses the applicability and the limitations of various modelling approaches and sediment transport formulations in MOUSE ST. The study was founded by the Swedish Water and Waste Works Association and the Nordic Industrial...

  18. Sediment Transport Model For Storm Sewer Networks Towards The Operational Risks

    Directory of Open Access Journals (Sweden)

    I. RÁTKY

    2016-11-01

    Full Text Available Sediment transport in sewer networks can be critical in economical and safety point of view. To improve the operation of the sewer networks we are presenting a model, which is capable of numerical simulations of the sediment transport in storm water network. The developed model is calculating the change of the particle distribution of the sediment fractions including the effects of settling and mixing up processes. The results of the model calculations in a simplified network are also presented. We are also planning to apply the developed sediment transport module by coupling to a hydrodynamic simulation for practical tasks supporting the design and operation of sewers networks.

  19. Principles and Approaches for Numerical Modelling of Sediment Transport in Sewers

    DEFF Research Database (Denmark)

    Mark, Ole; Appelgren, Cecilia; Larsen, Torben

    1995-01-01

    A study has been carried out with the objectives of describing the effect of sediment deposits on the hydraulic capacity of sewer systems and to investigate the sediment transport in sewer systems. A result of the study is a mathematical model MOUSE ST which describes sediment transport in sewers....... This paper discusses the applicability and the limitations of various modelling approaches and sediment transport formulations in in MOUSE ST. Further, the paper presents a simple application of MOUSE ST to the Rya catchment in Gothenburg, Sweden....

  20. International Sanitary Conferences from the Ottoman perspective (1851–1938

    Directory of Open Access Journals (Sweden)

    Nermin Ersoy

    2011-01-01

    Full Text Available The search for international measures to prevent and control epidemics of cholera, the plague, yellow fever, malaria and typhus which ravaged the world throughout the 19th century, led to a series of International Sanitary Conferences and Conventions under the leadership of European states. Between 1851 and 1938 fourteen conferences - Paris (1851, Paris (1859, Istanbul (1866, Vienna (1874, Washington D.C. (1881, Rome (1885, Venice (1892, Dresden (1893, Paris (1894, Venice (1897, Paris (1903, (1911, (1926 and (1938 - and eight conventions - 1892, 1893, 1894, 1897, 1903, 1912, 1926, 1938 were held. Both conferences and conventions shaped social life, health policies, politics, laws, and transportation, economic, commercial rules of the European, Asian and also American countries. In this study we reviewed the reasons, process and the results of each international sanitary conference from the Ottoman social and health perspective.

  1. Marketing Specialization in the Sanitary-Veterinary Field

    OpenAIRE

    Mihaela Cornelia Prejmerean

    2006-01-01

    Public health and food safety are main consumer rights in the European Union. Sanitary standards related to animal health, animal welfare, food production are developed and standardizEditura The objective is to detect, diagnose and control animal diseases and to have a safe food chain. Although the input of the animal health industry is low in the agricultural production, it allows European farmers to produce high quality meat and dairy products, minimise environmental impact. Romania as a fu...

  2. Interim Sanitary Landfill Groundwater Monitoring Report. 1997 Annual Report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-01-01

    Eight wells of the LFW series monitor groundwater quality in the Steed Pond Aquifer (Water Table) beneath the Interim Sanitary Landfill at the Savannah River Site (SRS). These wells are sampled semiannually to comply with the South Carolina Department of Health and Environmental Control Modified Municipal Solid Waste Permit 025500-1120 (formerly dWP-087A) and as part of the SRS Groundwater Monitoring Program.

  3. [The sanitary question in the modernity-postmodernity debate].

    Science.gov (United States)

    Iriart, C; Spinelli, H

    1994-12-01

    This work analyzes the sanitary question in the modernity-postmodernity debate. Such analyses are performed form a philosophical position that states the crisis of Modernity and questions the ideological twist that to itself propitiates postmodernity, shutting out questioning views or visions. It propitiates an alternative view of politics, thinking of it from the potency plane and giving a role to the subject in the decision of producing transformations.

  4. [Construction of the Brazilian Sanitary Surveillance System: arguments to debate].

    Science.gov (United States)

    De Seta, Marismary Horsth; Dain, Sulamis

    2010-11-01

    This paper analyzes the Brazilian Sanitary Surveillance System as an arrangement aimed at regulating and reducing health risks associated with consumption of products, use of health services and the environment. Historical, political and tax aspects were considered and their development compared with the National Health Surveillance System, which has received strong international cooperation. The comparison was based on the trajectory of their national systems and related federal agencies, as well as on criteria adopted for decentralization. The central category of analysis is federative coordination and was based on the framework of federalism and intergovernmental relations. The institutional context of health and sanitary surveillance presents strong political competition, instability in the project and probable reduction of the ability of federal coordination after the Pact for Health. The National Sanitary Surveillance System due to its nature of public good and high externality in its field of action requires federal coordination for increasing the regional and local cooperation, also because of the structural heterogeneity of Brazilian municipalities.

  5. Gamma and beta logging of underground sewer and process lines

    Energy Technology Data Exchange (ETDEWEB)

    Rangel, M.J.; Martz, D.E.; Langner, G.H. Jr.

    1989-11-01

    The GammaSnake can be useful for locating uranium mill tailings used as backfill for sewer lines or storm drains where the lines can be readily accessed from a cleanout access port or other opening. The time required to determine if contamination is present using the GammaSnake method is considerably less than when using the delta gamma or drilling methods. There is, also, less potential hazard to the equipment operators when using the GammaSnake method. The GammaSnake method is generally limited to a distance of 100 feet or less. Used with the MAC-51B line locator, the GammaSnake method can provide useful information without extensive drilling or surveying. 7 figs., 2 tabs.

  6. A framework for optimal reliability-based storm sewer network design in flat areas

    National Research Council Canada - National Science Library

    Haghighi, Ali; Samani, Hossein Mohammad Vali; Moussavi, Ali

    .... The model offers numerous design alternatives with various levels of reliability. The model was successfully applied to the Kianpars storm sewer network, a flat district of the city of Ahvaz in Iran...

  7. ANFIS-based approach for predicting sediment transport in clean sewer

    Science.gov (United States)

    Azamathulla, H. Md.; Ab. Ghani, Aminuddin; Fei, Seow Yen

    2012-01-01

    The necessity of sewers to carry sediment has been recognized for many years. Typically, old sewage systems were designated based on self-cleansing concept where there is no deposition in sewer. These codes were applicable to non-cohesive sediments (typically storm sewers). This study presents adaptive neuro-fuzzy inference system (ANFIS), which is a combination of neural network and fuzzy logic, as an alternative approach to predict the functional relationships of sediment transport in sewer pipe systems. The proposed relationship can be applied to different boundaries with partially full flow. The present ANFIS approach gives satisfactory results (r2 = 0.98 and RMSE = 0.002431) compared to the existing predictor. PMID:22389640

  8. Modelling Illicit Drug Fate in Sewers for Wastewater-Based Epidemiology

    DEFF Research Database (Denmark)

    Ramin, Pedram

    . After transport in sewers, these chemicals enter wastewater treatment plants (WWTPs). Monitoring campaigns are normally performed at WWTP influent to collect representative samples. Following quantitative chemical analysis, measured drug loads are used to estimate population-normalized parent drug......, are subject to physical, chemical or biological processes in sewers (fate processes). The occurrence of these processes may lead to significant change of drug loads at WWTP influent compared to source release points. Therefore, not accounting for these variations may negatively affect drug use estimates....... Sewer systems can be considered as biological reactors, in which the concentration of organic chemicals present in wastewater can be impacted by in-sewer processes during hydraulic residence time. Illicit drug biomarkers, as trace organic chemicals in the range of nanograms to micrograms per liter...

  9. Sewerage Collection Lines, Sewer Lines, Published in unknown, North Georgia College and State University.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Sewerage Collection Lines dataset, was produced all or in part from Field Survey/GPS information as of unknown. It is described as 'Sewer Lines'. Data by this...

  10. Sewerage Treatment Plants, Sewer Treatment Plant, Published in 2008, City of Elizabeth City.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Sewerage Treatment Plants dataset, was produced all or in part from Orthoimagery information as of 2008. It is described as 'Sewer Treatment Plant'. Data by...

  11. Design Of A Laboratory Set-up For Evaluating Structural Strength Of Deteriorated Concrete Sewer Pipes

    NARCIS (Netherlands)

    Stanic, N.; Salet, T.; Langeveld, J.G.; Clemens, F.H.L.R.

    2014-01-01

    The principle of structural behaviour of buried concrete pipes is fairly understood, except for how material deterioration affects structural behaviour and performance. Consequently, information on the structural behaviour of deteriorated sewer pipes will contribute to better understanding of the ch

  12. Predicting the Probability of Failure of Cementitious Sewer Pipes Using Stochastic Finite Element Method.

    Science.gov (United States)

    Alani, Amir M; Faramarzi, Asaad

    2015-06-10

    In this paper, a stochastic finite element method (SFEM) is employed to investigate the probability of failure of cementitious buried sewer pipes subjected to combined effect of corrosion and stresses. A non-linear time-dependant model is used to determine the extent of concrete corrosion. Using the SFEM, the effects of different random variables, including loads, pipe material, and corrosion on the remaining safe life of the cementitious sewer pipes are explored. A numerical example is presented to demonstrate the merit of the proposed SFEM in evaluating the effects of the contributing parameters upon the probability of failure of cementitious sewer pipes. The developed SFEM offers many advantages over traditional probabilistic techniques since it does not use any empirical equations in order to determine failure of pipes. The results of the SFEM can help the concerning industry (e.g., water companies) to better plan their resources by providing accurate prediction for the remaining safe life of cementitious sewer pipes.

  13. Remaining Sites Verification Package for the 1607-F5 Sanitary Sewer System (124-F-5), Waste Site Reclassification Form 2006-043

    Energy Technology Data Exchange (ETDEWEB)

    L. M. Dittmer

    2006-09-14

    The 1607-F5 waste site is a former septic tank, tile field, and associated pipeline located within the 100-FR-1 Operable Unit that received sewage from the former 181-F Pumphouse. Lead, gamma-chlordane, and heptachlor epoxide were identified within or around the septic system at concentrations exceeding the direct exposure cleanup criteria. Multiple metal and pesticide constituents were also identified as exceeding the groundwater and river protection cleanup criteria. The results of verification sampling demonstrated that residual contaminant concentrations do not preclude any future uses and allow for unrestricted use of shallow zone soils. The results also showed that residual contaminant concentrations are protective of groundwater and the Columbia River.

  14. Remaining Sites Verification Package for the 1607-B2 Septic System and 100-B-14:2 Sanitary Sewer System, Waste Site Reclassification Form 2006-055

    Energy Technology Data Exchange (ETDEWEB)

    L. M. Dittmer

    2007-03-21

    The 1607-B2 waste site is a former septic system associated with various 100-B facilities, including the 105-B, 108-B, 115-B/C, and 185/190-B buildings. The site was evaluated based on confirmatory results for feeder lines within the 100-B-14:2 subsite and determined to require remediation. The 1607-B2 waste site has been remediated to achieve the remedial action objectives specified in the Remaining Sites ROD. The results of verification sampling show that residual contaminant concentrations do not preclude any future uses and allow for unrestricted use of shallow zone soils. The results also demonstrate that residual contaminant concentrations are protective of groundwater and the Columbia River.

  15. Remaining Sites Verification Package for the 100-F-31, 144-F Sanitary Sewer System, Waste Site Reclassification Form 2006-033

    Energy Technology Data Exchange (ETDEWEB)

    L. M. Dittmer

    2006-08-24

    The 100-F-31 waste site is a former septic system that supported the inhalation laboratories, also referred to as the 144-F Particle Exposure Laboratory (132-F-2 waste site), which housed animals exposed to particulate material. The 100-F-31 waste site has been remediated to achieve the remedial action objectives specified in the Remaining Sites ROD. The results of verification sampling show that residual contaminant concentrations do not preclude any future uses and allow for unrestricted use of shallow zone soils. The results also demonstrate that residual contaminant concentrations are protective of groundwater and the Columbia River.

  16. Sewerage Treatment Plants, Treatment plants included in sanitary sewer layer above, Published in Not Provided, 1:600 (1in=50ft) scale, Town of Franklin.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Sewerage Treatment Plants dataset, published at 1:600 (1in=50ft) scale, was produced all or in part from Field Survey/GPS information as of Not Provided. It is...

  17. Sewerage Pumping Stations, Pumping stations included in sanitary sewer system data above, Published in Not Provided, 1:600 (1in=50ft) scale, Town of Franklin.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Sewerage Pumping Stations dataset, published at 1:600 (1in=50ft) scale, was produced all or in part from Field Survey/GPS information as of Not Provided. It is...

  18. A generalized Dynamic Overflow Risk Assessment (DORA) for urban drainage RTC

    DEFF Research Database (Denmark)

    Vezzaro, Luca; Grum, Morten

    2012-01-01

    ) the expected runoff volume (calculated by radar-based rainfall forecast models) and (iii) the estimated uncertainty of the runoff forecasts. The inclusion of uncertainty allows a more confident use of Real Time Control (RTC). Overflow risk is calculated by a flexible function which allows prioritization......An innovative generalized approach for integrated real time control of urban drainage systems is presented. The Dynamic Overflow Risk Assessment (DORA) strategy tries to minimize the expected overflow risk by considering (i) the water volume presently stored in the drainage network, (ii...... of the discharge points according to their sensitivity. DORA was tested on an example inspired by a catchment in the city of Aarhus (Denmark). By using a simple conceptual model, a statistical analysis of the performance of DORA was performed. Compared to a traditional local control approach, DORA contributed...

  19. Soft Sensing of Overflow Particle Size Distributions in Hydrocyclones Using a Combined Method

    Institute of Scientific and Technical Information of China (English)

    SUN Zhe; WANG Huangang; ZHANG Zengke

    2008-01-01

    Precise, real-time measurements of overflow particle size distributions in hydrocyclones are ne-cessary for accurate control of the comminution circuits. Soft sensing measurements provide real-time,flexible, and low-cost measurements appropriate for the overflow particle size distributions in hydrocyclones.Three soft sensing methods were investigated for measuring the overflow particle size distributions in hy-drocyclones. Simulations show that these methods have various advantages and disadvantages. Optimal Bayesian estimation fusion was then used to combine three methods with the fusion parameters determined according to the performance of each method with validation samples. The combined method compensates for the disadvantages of each method for more precise measurements. Simulations using real operating data show that the absolute root mean square measurement error of the combined method was always about 2% and the method provides the necessary accuracy for beneflciation plants.

  20. Quick Analysis Method for Estimating Debris Flow Prone Area Caused by Overflow from Landslide dam

    Science.gov (United States)

    Shimizu, T.; Uchida, T.; Yamakoshi, T.; Yoshino, K.; Kisa, H.; Ishizuka, T.; Kaji, A.

    2012-04-01

    When earthquake or torrential rainfall cause deep catastrophic landslides, landslide dams can be formed in mountainous region. If water overflows from the landslide dams, large scale debris flow can occurs and possibly causes serious disasters in the downward region. Debris flow caused by the overflow from landslide dam is possible to affect the larger area than normal debris flow and flash flood. It is important for both a decision maker and resident in the area to recognize the disaster prone area as early as possible. For that reason, it is important to establish a quick analysis method for estimating debris flow prone area caused by overflow from landslide dams under the emergency situation. This situation requires the method to have both accuracy and speed for release. Nonetheless these two factors have trade-off relationship. We recently developed the quick analysis method to estimate debris flow disaster prone area caused by overflow from landslide dams. The method including the ways of efficient survey and numerical simulation programs called QUAD-L (QUick Analysis system for Debris flow caused by Landslide dam overflow). Our quick analysis system was actually applied to show the area for evacuation against debris flow caused by overflow from landslide dam formed by the 2011 Typhoon Talas which hit mainly the central region of Japan on September 2-4th, 2011. In addition to background of this application, since May 1st, 2011, Erosion and Sediment Control (SABO) Department of the Ministry of Land, Infrastructure, Transport and Tourism, Japan (MLIT) launched a new scheme using above-mentioned quick analysis method.

  1. Sewerage Sludge Disposal and Application Sites, NBC Sewer Overflows; c07uso97; Combined sewer overflow and waste water discharge points managed by the Narragansett bay commission - NBC - in Providence county RI, Published in 1996, 1:4800 (1in=400ft) scale, State of Rhode Island and Providence Plantations.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Sewerage Sludge Disposal and Application Sites dataset, published at 1:4800 (1in=400ft) scale, was produced all or in part from Hardcopy Maps information as of...

  2. Sensitivity of the Denmark Strait Overflow to various parameterizations in a z-coordinate numerical model

    Science.gov (United States)

    Colombo, Pedro; Barnier, Bernard; Penduff, Thierry; Molines, Jean-Marc

    2016-04-01

    Overflows play a key role in the climate system by ventilating deep waters, feeding boundary currents and determining the stratification of the deep ocean. Their correct representation is still an open issue in geopotential-coordinate global ocean models, and leads to misrepresentations of deep and bottom water masses. In this work we quantify the sensitivity of a realistic Denmark Strait regional configuration of the NEMO OGCM at 1/12° horizontal resolution to various parameters: partial vs full cells, use of a bottom boundary layer parameterization, and vertical resolution. We also provide a quantification of the spurious dyapicnal mixing present in the overflow through a passive tracer online release experiment.

  3. OVERFLOW Simulations of Space Shuttle Orbiter Reentry Based on As-Built Geometry

    Science.gov (United States)

    Ma, Edward C.; Vicker, Darby J.; Campbell, Charles H.; Wilson, Brad; Pavek, Mike; Berger, Karen

    2012-01-01

    The Space Shuttle Orbiters Discovery and Endeavor have been digitally scanned to obtain outer mold line surfaces. Using these scans, the existing overset computational fluid dynamics (CFD) grid system will be modified by projecting the grid points to the scanned geometry. Simulations will be performed using the OVERFLOW solver and the results compared to previous OVERFLOW results on the theoretical geometry and the aerodynamic databook. The "bent airframe" term will be compared between the aerodynamic databook and the computations over a range of reentry conditions.

  4. Application of the Wallingford Procedure to sewer network rehabilitation; Rehabilitacion de redes de alcantarillado. Aplicando el sistema de Wallingford

    Energy Technology Data Exchange (ETDEWEB)

    Gomez, M. [Universidad Politecnica de de Cataluna. Barcelona (Spain); Lopez, R. [Universitat de Lleida. Lleida (Spain)

    1999-11-01

    In this paper we present a summary of the Wallingford Procedure application to sewer network rehabilitation studies. After the methodology of the Procedure is revised, an application to a sewer network of Sant Boi de Llobregat is showed. Flow survey campaigns, calibration and validation processes and the alternative proposed to improve the initial situation are described. Finally, the benefits to apply such methodologies to the sewer network rehabilitation analysis are exposed. (Author) 3 refs.

  5. Application of the Wallingford Procedure to sewer network rehabilitation. Rehabilitacion de redes de alcantarillado. Aplicando el sistema de Wallingford

    Energy Technology Data Exchange (ETDEWEB)

    Gomez, M. (Universidad Politecnica de de Cataluna. Barcelona (Spain)); Lopez, R. (Universitat de Lleida. Lleida (Spain))

    1999-01-01

    In this paper we present a summary of the Wallingford Procedure application to sewer network rehabilitation studies. After the methodology of the Procedure is revised, an application to a sewer network of Sant Boi de Llobregat is showed. Flow survey campaigns, calibration and validation processes and the alternative proposed to improve the initial situation are described. Finally, the benefits to apply such methodologies to the sewer network rehabilitation analysis are exposed. (Author) 3 refs.

  6. The application of irradiation to phyto sanitary problems

    Energy Technology Data Exchange (ETDEWEB)

    Ross, R.T. [USDA/APHIS/PPQ. Department of Agriculture, Room 1630 Soagribg, 1400 Independence Ave. Sw. Mail Code Stop 3438, 20250 Washington D.C. (United States)

    1997-12-31

    The first formally adopted regulatory policy for irradiation as a phyto sanitary treatment in the United States was issued in 1989 and was based on Title 7 of the Code of Federal Regulations. These regulations authorized irradiation as a quarantine treatment for papayas intended for movement from the State of Hawaii to the continental United States (U.S.), Guam, Puerto Rico, and the U.S. Virgin Islands. This authorization was specific for commodity, place of origin, and program, but was designed for a complex of three fruit flies rather than a single pest. Routine commercial shipments were never realized under this regulation due to the lack of a treatment facility in Hawaii. However, the authorization has proven useful from the standpoint of beginning to establish policies for irradiation as a phyto sanitary treatment in the United States. The United States Department of Agriculture (USDA), Animal and Plant Health Inspection Service (APHIS), Plant Protection and Quarantine (PPQ) remains dedicated to using the most up-to-date, appropriate and least intrusive technology to provide quarantine security. The need for alternative treatments for pests mitigation systems is greater than ever. Global trade pressures and the possible loss of methyl bromide make it imperative that all practical treatment options be explored. Since 1989 irradiation treatment concepts have matured significantly. Technological advances, greater experience, and an increasingly larger body of research indicate that irradiation has important potential as a treatment for quarantine pest problems. It is in this light that PPQ is expanding its regulatory framework, is addressing irradiation treatment options, and is developing comprehensive policy statements intended to facilitate the development and formalization of new treatments for phyto sanitary applications. (Author)

  7. Characterization and toxicological evaluation of leachate from closed sanitary landfill.

    Science.gov (United States)

    Emenike, Chijioke U; Fauziah, Shahul H; Agamuthu, P

    2012-09-01

    Landfilling is a major option in waste management hierarchy in developing nations. It generates leachate, which has the potential of polluting watercourses. This study analysed the physico-chemical components of leachate from a closed sanitary landfill in Malaysia, in relation to evaluating the toxicological impact on fish species namely Pangasius sutchi S., 1878 and Clarias batrachus L., 1758. The leachate samples were taken from Air Hitam Sanitary Landfill (AHSL) and the static method of acute toxicity testing was experimented on both fish species at different leachate concentrations. Each fish had an average of 1.3 ± 0.2 g wet weight and length of 5.0 ± 0.1 cm. Histology of the fishes was examined by analysing the gills of the response (dead) group, using the Harris haemtoxylin and eosin (H&E) method. Finneys' Probit method was utilized as a statistical tool to evaluate the data from the fish test. The physico-chemical analysis of the leachate recorded pH 8.2 ± 0.3, biochemical oxygen demand 3500 ± 125 mg L(-1), COD 10 234 ± 175 mg L(-1), ammonical nitrogen of 880 ± 74 mg L(-1), benzene 0.22 ± 0.1 mg L(-1) and toluene 1.2 ± 0.4 mg L(-1). The 50% lethality concentration (LC(50)) values calculated after 96 h exposure were 3.2% (v/v) and 5.9% (v/v) of raw leachate on P. sutchi and C. batrachus, respectively. The H&E staining showed denaturation of the nucleus and cytoplasm of the gills of the response groups. Leachate from the sanitary landfill was toxic to both fish species. The P. sutchi and C. batrachus may be used as indicator organisms for leachate pollution in water.

  8. [Transport and sources of runoff pollution from urban area with combined sewer system].

    Science.gov (United States)

    Li, Li-Qing; Yin, Cheng-Qing

    2009-02-15

    Sampling and monitoring of runoff and sewage water in Wuhan urban area with combined sewer system were carried out during the period from 2003 to 2006, to study the transport and sources of runoff pollution at the catchment scale coupled with environmental geochemistry method. The results showed a change in quality between the runoff entering the sewer network and the combined storm water flow at the sewer's outlet. A significant increase was observed in the concentrations of total suspended solids (TSS), volatile suspended solids (VSS), COD, TN, and TP, and in the proportion of COD linked to particles. During the runoff production and transport, the concentrations of TSS and COD increased from 18.7 mg/L and 37.0 mg/L in roof runoff, to 225.3 mg/L and 176.5 mg/L in street runoff, and to 449.7 mg/L and 359.9 mg/L in combined storm water flow, respectively. The proportion of COD linked to particles was increased by 18%. In addition, the total phosphorus (P) and iron (Fe) contents in urban ground dust, storm drain sediment, sewage sewer sediment and combined sewer sediment were measured to identify the potential sources of suspended solids in the combined flow. The urban ground dust andstorm drain sediment wererich in Fe, whereas the sewage sewer sediment was rich in P. The P/Fe ratios in these groups were significantly distinct and able to differentiate them. A calculation of the two storm events based on the P/Fe rations showed that 56% +/- 26% of suspended solids in combined flow came from urban ground and storm drain. The rest wer e originated from the sewage sewer sediments which deposited in combined sewer on the dry weather days and were eroded on the wet weather days. The combined sewer network not only acts as a transport system, but also constitutes a physicochemical reactor that degrades the quality of urban water. Reducing the in-sewer pollution stocks would effectively control urban runoff pollution.

  9. Methods of Sensing Land Pollution from Sanitary Landfills

    Science.gov (United States)

    Nosanov, Myron Ellis; Bowerman, Frank R.

    1971-01-01

    Major cities are congested and large sites suitable for landfill development are limited. Methane and other gases are produced at most sanitary landfills and dumps. These gases may migrate horizontally and vertically and have caused fatalities. Monitoring these gases provides data bases for design and construction of safe buildings on and adjacent to landfills. Methods of monitoring include: (1) a portable combustible gas indicator; and (2) glass flasks valved to allow simultaneous exhaust of the flask and aspiration of the sample into the flask. Samples are drawn through tubing from probes as deep as twenty-five feet below the surface.

  10. MATERIALS FOR THE FINAL COVER OF SANITARY LANDFILLS

    Directory of Open Access Journals (Sweden)

    Davorin Kovačić

    1994-12-01

    Full Text Available The paper deals with the selection of materials for the sea¬ling layer in the final cover of sanitary landfills. The sealing la¬yer is the most critical component of the final cover. Its role is to minimize percolation of water through the final cover. Ma¬terials used for the construction of the sealing layer are either of mineral origin (compacted clay or geosynthetic (geomem¬brane. They are most often used in combination creating com¬posite liners. Recently alternative materials are also used like paper mill sludge or discarded swelling clay.

  11. Sanitary-hygienic and ecological aspects of beryllium production

    Energy Technology Data Exchange (ETDEWEB)

    Dvinskykh, E.M.; Savchuk, V.V.; Sidorov, V.L.; Slobodin, D.B.; Tuzov, Y.V. [Ulba Metallurgical Plant, Ust-Kamenogorsk (Kazakhstan)

    1998-01-01

    The Report describes An organization of sanitary-hygienic and ecological control of beryllium production at Ulba metallurgical plant. It involves: (1) the consideration of main methods for protection of beryllium production personnel from unhealthy effect of beryllium, (2) main kinds of filters, used in gas purification systems at different process areas, (3) data on beryllium monitoring in water, soil, on equipment. This Report also outlines problems connected with designing devices for a rapid analysis of beryllium in air as well as problems of beryllium production on ecological situation in the town. (author)

  12. [Sanitary and chemical protection during the Great Patriotic War].

    Science.gov (United States)

    Imangulov, R G; Grebeniuk, A N; Rybalko, V M; Nosov, A V

    2011-05-01

    During the Great Patriotic War (1941-1945) there was a real danger of use by German armies of the chemical weapon against staff of Red Army. However German command didn't risked to go on conducting large-scale chemical war against the USSR that rescued from painful death millions person. A principal cause of this decision was well organized and technically provided system of antigas protection in Red Army, including precisely organized actions of sanitary-chemical protection, qualitative preparation of military doctors on these questions and presence at them effective antidotes and other means of treatment of injuries by fighting poison gases.

  13. Multi-objective evolutionary optimization for greywater reuse in municipal sewer systems.

    Science.gov (United States)

    Penn, Roni; Friedler, Eran; Ostfeld, Avi

    2013-10-01

    Sustainable design and implementation of greywater reuse (GWR) has to achieve an optimum compromise between costs and potable water demand reduction. Studies show that GWR is an efficient tool for reducing potable water demand. This study presents a multi-objective optimization model for estimating the optimal distribution of different types of GWR homes in an existing municipal sewer system. Six types of GWR homes were examined. The model constrains the momentary wastewater (WW) velocity in the sewer pipes (which is responsible for solids movement). The objective functions in the optimization model are the total WW flow at the outlet of the neighborhoods sewer system and the cost of the on-site GWR treatment system. The optimization routing was achieved by an evolutionary multi-objective optimization coupled with hydrodynamic simulations of a representative sewer system of a neighborhood located at the coast of Israel. The two non-dominated best solutions selected were the ones having either the smallest WW flow discharged at the outlet of the neighborhood sewer system or the lowest daily cost. In both solutions most of the GWR types chosen were the types resulting with the smallest water usage. This lead to only a small difference between the two best solutions, regarding the diurnal patterns of the WW flows at the outlet of the neighborhood sewer system. However, in the upstream link a substantial difference was depicted between the diurnal patterns. This difference occurred since to the upstream links only few homes, implementing the same type of GWR, discharge their WW, and in each solution a different type of GWR was implemented in these upstream homes. To the best of our knowledge this is the first multi-objective optimization model aimed at quantitatively trading off the cost of local/onsite GW spatially distributed reuse treatments, and the total amount of WW flow discharged into the municipal sewer system under unsteady flow conditions.

  14. Assessment of pollutants and gaseous emissions in sewer network in NCT of Delhi.

    Science.gov (United States)

    Aswale, P; Rao, N N; Karthik, M; Dhodapkar, R; Patkar, G; Nandy, T

    2012-04-01

    The NCT of Delhi in India handles domestic sewage through a long sewerage networks. The network is into eight divisions. The aim of the present study is to arrive at a correlation between sewage quality and gas emissions in the sewer network of various divisions. This will aid in forewarning the sewer workers about the safety precautions. The health effects due to toxic sewer gases exposure and assessment of hazardous conditions and hazard potential are discussed. The study areas were broadly classified as residential, commercial, industrial and mix (combination of residential & commercial) for comparison. Sewage samples were collected from 1020 sites and analyzed for 10 different physicochemical parameters. The analytical data revealed wide variation in the chemical composition of sewage flowing at various sewerage network sites. Based on comparison with the regulatory standard for discharge in sewers, 89 sites with higher values of BOD and sulphate were marked as critical sites. Subsequently, the concentrations of CH4 and H2S in sewer emissions were determined for the 89 critical sites through onsite monitoring. Samples from 22 sites had significantly higher concentration of CH4 than the LEL and those from 40 sites showed concentrations higher than the LFL. On the other hand, samples from 38 locations showed significantly high H2S concentration, more than permissible limit of 10 ppm. The sewer workers in North East, North West and West region of the metropolis were exposed to hazards from excessive CH4 and H2S emissions, whereas those under South and South West regions were more vulnerable to H2S related risks. The sewer network under North, Central and South poses relatively less hazard with regard to gaseous emissions.

  15. Aerobic Heterotrophic Biodégradation in Polluted Drains and Sewers: The drain and sewer as dual-phase biological reactors

    NARCIS (Netherlands)

    Cao, Y.S.

    1994-01-01

    Wastewater collection systems such as sewers, sewage drains, and polluted shallow aquatic systems such as rivers, streams, and lagoons are characterized by the fact that both suspended and attached biomass exist and function. They are dual-phase systems. Contrary to biofilm dominated systems such as

  16. A fast cross-entropy method for estimating buffer overflows in queueing networks

    NARCIS (Netherlands)

    Boer, de P.T.; Kroese, D.P.; Rubinstein, R.Y.

    2004-01-01

    In this paper, we propose a fast adaptive importance sampling method for the efficient simulation of buffer overflow probabilities in queueing networks. The method comprises three stages. First, we estimate the minimum cross-entropy tilting parameter for a small buffer level; next, we use this as a

  17. Importance Sampling Simulation of Population Overflow in Two-node Tandem Networks

    NARCIS (Netherlands)

    Nicola, Victor F.; Zaburnenko, Tatiana S.; Baier, C.; Chiola, G.; Smirni, E.

    2005-01-01

    In this paper we consider the application of importance sampling in simulations of Markovian tandem networks in order to estimate the probability of rare events, such as network population overflow. We propose a heuristic methodology to obtain a good approximation to the 'optimal' state-dependent ch

  18. Lobe Overflow as the Likely Cause of Pericenter Outburst in an SMBH Orbiter

    CERN Document Server

    Wilson, R E

    2015-01-01

    A very large lobe overflow event is suggested to explain the $0.^m4$ brightening observed in K band at pericenter passage of the star known as S2 that orbits the Galaxy's supermassive black hole (SMBH). Known observed properties of S2 that contribute to lobe filling are 1) the enormous mass ratio, $M_{SMBH}/M_{S2}$, 2) S2's fast rotation, and 3) S2's large orbital eccentricity. Published estimates have given limiting lobe sizes of order 100 to 300 $R_\\odot$ but, with S2's fast rotation taken into account, the computed lobe size is much smaller, being compatible with either a main sequence OB star or a stripped evolved star. An important evolutionary consideration that predicts very large pericenter overflows is envelope expansion following mass loss that is characteristic of highly evolved stars. Material removed by lobe overflow at pericenter is replenished by envelope expansion as an evolved star awaits its next pericenter passage. An observational signature of lobe overflow for upcoming pericenter passages...

  19. CO-RELEASED ADRENALINE MARKEDLY FACILITATES NORADRENALINE OVERFLOW THROUGH PREJUNCTIONAL BETA(2)-ADRENOCEPTORS DURING SWIMMING EXERCISE

    NARCIS (Netherlands)

    COPPES, RP; SMIT, J; BENTHEM, L; VANDERLEEST, J; ZAAGSMA, J

    1995-01-01

    The effect of intravenously applied (-)adrenaline, taken up by and released from sympathetic nerves, on swimming exercise-induced noradrenaline overflow in permanently cannulated adrenal demedullated rats was studied. Adrenaline (100 ng/min) was infused for 2 h, during which a plasma concentration o

  20. Proces-based modeling of the overflow induced growth of erosional channels

    NARCIS (Netherlands)

    Tuan, T.Q.; Stive, M.J.F.; Verhagen, H.J.; Visser, P.J.

    2008-01-01

    A new process-based approach is introduced for a more efficient computation of the overflow-induced growth of an erosional channel in a noncohesive homogeneous narrow landmass such as the breach growth in a sand-dike. The approach is easy to incorporate in a 1D/2DV morphodynamic model to compute the

  1. The 8 July 2002 storm over Athens: analysis of the Kifissos River/Canal overflows

    Directory of Open Access Journals (Sweden)

    K. Mazi

    2006-01-01

    Full Text Available We analyse the flood event of 8 July 2002 that caused overflows over portions of the lower reach of the Kifissos River/Canal. The storm covered only the lower basin area and was concentrated on the centre and the southwest side of Greater Athens. The issue that stirred the public opinion was whether the hydraulic works underway in lower Kifissos at that time were responsible for the overflows. We explore this issue with the hydrologic-hydraulic model of the Kifissos basin TELESIM. To shed light on the probable cause of the observed flooding, we ran TELESIM for two rain-field scenarios derived from the recorded point-rainfalls, computing flows for each scenario. Depth profiles for channel conditions without obstructions do not explain the observed flooding. With the channel taken as locally obstructed by flow-area reducing ramps plus bed-debris, estimated nominal overflows (bank-full level is threshold, but the water stays inside the channel compare well with actual ones for the milder rainfall scenario. Hence, the simulations support as plausible the hypothesis that flow obstructions due to the construction caused the overflows.

  2. Interim sanitary landfill groundwater monitoring report. 1996 Annual report

    Energy Technology Data Exchange (ETDEWEB)

    Bagwell, L.A.

    1997-01-01

    Eight wells of the LFW series monitor groundwater quality in the Steed Pond Aquifer (Water Table) beneath the Interim Sanitary Landfill at the Savannah River Site. These wells are sampled semiannually to comply with the South Carolina Department of Health and Environmental Control Modified Municipal Solid Waste Permit 025500-1120 and as part of the SRS Groundwater Monitoring Program. Trichlorofluoromethane and 1,1,1-trichloroethane were elevated in one sidegradient well and one downgradient well during 1996. Zinc was elevated in three downgradient wells and also was detected in the associated laboratory blanks for two of those wells. Specific conductance was elevated in one background well and one sidegradient well. Barium and copper exceeded standards in one sidegradient well, and dichloromethane (a common laboratory contaminant) was elevated in another sidegradient well. Barium, copper, and dichloromethane were detected in the associated blanks for these wells, also. The groundwater flow direction in the Steed Pond Acquifer (Water Table) beneath the Interim Sanitary Landfill was to the southeast (universal transverse Mercator coordinates). The flow rate in this unit was approximately 210 ft/year during first quarter 1996 and 180 ft/yr during third quarter 1996.

  3. 30 CFR 75.1712-8 - Application for waiver of location requirements for underground sanitary facilities.

    Science.gov (United States)

    2010-07-01

    ... underground sanitary facilities. Applications for waivers of the location requirements of § 75.1712-6 shall be... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Application for waiver of location requirements for underground sanitary facilities. 75.1712-8 Section 75.1712-8 Mineral Resources MINE SAFETY AND...

  4. [Scientific and practical substantiation of the methodology for sanitary-epidemiological auditing procedure for educational institutions].

    Science.gov (United States)

    Safonkina, S G; Ivanenko, A V; Kuchma, B R

    2012-01-01

    The implementation of sanitary and epidemiological auditing - a promising trend in the sanitary-epidemiological well-being of the population including children. Thus, it provides pupils' rights on the safety conditions of educational activities for their life and health without toughening of administrative influence.

  5. Influence of pipe material and surfaces on sulfide related odor and corrosion in sewers.

    Science.gov (United States)

    Nielsen, Asbjørn Haaning; Vollertsen, Jes; Jensen, Henriette Stokbro; Wium-Andersen, Tove; Hvitved-Jacobsen, Thorkild

    2008-09-01

    Hydrogen sulfide oxidation on sewer pipe surfaces was investigated in a pilot scale experimental setup. The experiments were aimed at replicating conditions in a gravity sewer located immediately downstream of a force main where sulfide related concrete corrosion and odor is often observed. During the experiments, hydrogen sulfide gas was injected intermittently into the headspace of partially filled concrete and plastic (PVC and HDPE) sewer pipes in concentrations of approximately 1,000 ppm(v). Between each injection, the hydrogen sulfide concentration was monitored while it decreased because of adsorption and subsequent oxidation on the pipe surfaces. The experiments showed that the rate of hydrogen sulfide oxidation was approximately two orders of magnitude faster on the concrete pipe surfaces than on the plastic pipe surfaces. Removal of the layer of reaction (corrosion) products from the concrete pipes was found to reduce the rate of hydrogen sulfide oxidation significantly. However, the rate of sulfide oxidation was restored to its background level within 10-20 days. A similar treatment had no observable effect on hydrogen sulfide removal in the plastic pipe reactors. The experimental results were used to model hydrogen sulfide oxidation under field conditions. This showed that the gas-phase hydrogen sulfide concentration in concrete sewers would typically amount to a few percent of the equilibrium concentration calculated from Henry's law. In the plastic pipe sewers, significantly higher concentrations were predicted because of the slower adsorption and oxidation kinetics on such surfaces.

  6. Sewage flow optimization algorithm for large-scale urban sewer networks based on network community division

    Institute of Scientific and Technical Information of China (English)

    Lihui CEN; Yugeng XI

    2008-01-01

    By considering the flow control of urban sewer networks to minimize the electricity consumption of pumping stations.a decomposition-coordination strategy for energy savings based on network community division is developed in this paper. A mathematical model characterizing the smady-state flow of urball sewer networks is first constructed,consisting of a set of algebraic equations with the structure transportation capacities captured as constraints.Since the sewer networks have no apparent natural hierarchical structure in general.it is very difficult to identify the clustered groups.A fast network division approach through calculating the betweenness of each edge is successfully applied to identify the groups and a sewer network with arbitrary configuration could be then decomposed into subnetworks.By integrating the coupling constraints of the subnetworks.the original problem is separated into N optimization subproblems in accordance with the network decomposition.Each subproblem is solved locally and the solutions to the subproblems are coordinated to form an appropriate global solution.Finally,an application to a specified large-scale sewer network is also investigated to demonstrate the validity of the proposed algorithm.

  7. Using Caffeine as a Water Quality Indicator in the Ambient Monitoring Program for Third Fork Creek Watershed, Durham, North Carolina

    OpenAIRE

    2015-01-01

    Caffeine has been suggested as a chemical indicator for domestic wastewater in freshwater systems, although it is not included in water quality monitoring programs. The Third Fork Creek watershed in Durham, NC, is highly urbanized, with a history of receiving untreated wastewater from leaking and overflowing sanitary sewers. The poor water quality originating in the Third Fork Creek watershed threatens its intended uses and jeopardizes drinking water, aquatic life, and recreational activities...

  8. 40 CFR 122.28 - General permits (applicable to State NPDES programs, see § 123.25).

    Science.gov (United States)

    2010-07-01

    ..., combined sewer overflows, municipal separate storm sewer systems, primary industrial facilities, and storm...) Designated planning areas under sections 208 and 303 of CWA; (ii) Sewer districts or sewer authorities;...

  9. Structure and forcing of the overflow at the Storfjorden sill and its connection to the Arctic coastal polynya in Storfjorden

    Directory of Open Access Journals (Sweden)

    F. Geyer

    2010-03-01

    Full Text Available Storfjorden (Svalbard is a sill-fjord with an active polynya and exemplifies the dense water formation process over the Arctic shelves. Here we report on our simulations of Storfjorden covering the freezing season of 1999–2000 using an eddy-permitting 3-D ocean circulation model with a fully coupled dynamic and thermodynamic sea-ice model. The model results in the polynya region and of the dense water plume flowing over the sill crest are compared to observations. The connections of the overflow at the sill to the dense water production at the polynya and to the local wind forcing are investigated. Both the overflow and the polynya dynamics are found to be sensitive to wind forcing. In response to freezing and brine rejection over the polynya, the buoyancy forcing initiates an abrupt positive density anomaly. While the ocean integrates the buoyancy forcing over several polynya events (about 25 days, the wind forcing dominates the overflow response at the sill at weather scale. In the model, the density excess is diluted in the basin and leads to a gradual build-up of dense water behind the sill. The overflow transport is typically inferred from observations using a single current profiler at the sill crest. Despite the significant variability of the plume width, we show that a constant overflow width of 15 km produces realistic estimates of the overflow volume transport. Another difficulty in monitoring the overflow is measuring the plume thickness in the absence of hydrographic profiles. Volume flux estimates assuming a constant plume width and the thickness inferred from velocity profiles explain 58% of the modelled overflow volume flux variance and agrees to within 10% when averaged over the overflow season.

  10. Structure and forcing of the overflow at the Storfjorden sill and its connection to the Arctic coastal polynya in Storfjorden

    Directory of Open Access Journals (Sweden)

    F. Geyer

    2010-01-01

    Full Text Available The formation of deep and intermediate waters in the Arctic Ocean is primarily due to high salinity shelf waters sinking down the continental slopes. Storfjorden (Svalbard is a sill-fjord with an active polynya and exemplifies the dense water formation process over the Arctic shelves. Here we report on our simulations of Storfjorden covering the freezing season of 1999–2000 using an eddy-permitting 3-D ocean circulation model with a fully coupled dynamic and thermodynamic sea-ice model. The model results in the polynya region and of the dense water plume flowing over the sill crest are compared to observations. The connections of the overflow at the sill to the dense water production at the polynya and to the local wind forcing are investigated. Both the overflow and the polynya dynamics are found to be sensitive to wind forcing. In response to freezing and brine rejection over the polynya, the buoyancy forcing initiates an abrupt positive density anomaly. While the ocean integrates the buoyancy forcing over several polynya events (about 25 days, the wind forcing dominates the overflow response at the sill at weather scale. In the model, the density excess is diluted in the basin and leads to a gradual build-up of dense water behind the sill. The overflow transport is typically inferred from observations using a single current profiler at the sill crest. Despite the significant variability of the plume width, we show that a constant overflow width of 15 km produces realistic estimates of the overflow volume transport. Another difficulty in monitoring the overflow is measuring the plume thickness in the absence of hydrographic profiles. Volume flux estimates assuming a constant plume width and the thickness inferred from velocity profiles explain 58% of the modelled overflow volume flux variance and agrees to within 10% when averaged over the overflow season.

  11. Heat modeling of wastewater in sewer networks: Determination of thermal energy content from sewage with modeling tools

    NARCIS (Netherlands)

    Elias Maxil, J.A.

    2015-01-01

    This text presents an approach to assess the energy content (flow and temperature) at any point of the sewer system based on the coupling of a stochastic model to predict drinking water demand from households and a model to estimate the temperature distribution in the sewer network. An application e

  12. Application of Morphological Segmentation to Leaking Defect Detection in Sewer Pipelines

    Directory of Open Access Journals (Sweden)

    Tung-Ching Su

    2014-05-01

    Full Text Available As one of major underground pipelines, sewerage is an important infrastructure in any modern city. The most common problem occurring in sewerage is leaking, whose position and failure level is typically identified through closed circuit television (CCTV inspection in order to facilitate rehabilitation process. This paper proposes a novel method of computer vision, morphological segmentation based on edge detection (MSED, to assist inspectors in detecting pipeline defects in CCTV inspection images. In addition to MSED, other mathematical morphology-based image segmentation methods, including opening top-hat operation (OTHO and closing bottom-hat operation (CBHO, were also applied to the defect detection in vitrified clay sewer pipelines. The CCTV inspection images of the sewer system in the 9th district, Taichung City, Taiwan were selected as the experimental materials. The segmentation results demonstrate that MSED and OTHO are useful for the detection of cracks and open joints, respectively, which are the typical leakage defects found in sewer pipelines.

  13. Controlling sewer systems – a critical review based on systems in three EU cities

    DEFF Research Database (Denmark)

    Mollerup, Ane Loft; Mikkelsen, Peter Steen; Thornberg, D.

    2017-01-01

    . With the basis of existing frameworks for control system design, a new time-scale dependent framework is proposed. We believe this comprehensive time-scale dependent framework can help water utilities to retrofit and design new control solutions and facilitate knowledge sharing about existing designs.......The term Real Time Control (RTC) is widely used to describe all types of control systems in sewer systems. Today the term covers everything from the simplest to the most advanced types of control systems, making it difficult to communicate about sewer system control in a precise manner, as well...... as search and find specific types of control systems for comparison. Through a survey of implemented control systems in three EU cities today and with the perspectives of current research within the field of sewer system control, the needs for a new control system design framework is identified...

  14. The role of iron in sulfide induced corrosion of sewer concrete.

    Science.gov (United States)

    Jiang, Guangming; Wightman, Elaine; Donose, Bogdan C; Yuan, Zhiguo; Bond, Philip L; Keller, Jurg

    2014-02-01

    The sulfide-induced corrosion of concrete sewer is a widespread and expensive problem for water utilities worldwide. Fundamental knowledge of the initiation and propagation of sewer corrosion, especially the interactions between chemical reactions and physical structure changes, is still largely unknown. Advanced mineral analytical techniques were applied to identify the distribution of corrosion products and the micro-cracking that developed along the corrosion boundary. It was found that sewer concrete corrosion caused by reactions with sulfuric acid progressed uniformly in the cement of concrete. In contrast to conventional knowledge, iron rust rather than gypsum and ettringite was likely the factor responsible for cracking ahead of the corrosion front. The analysis also allowed quantitative determination of the major corrosion products, i.e., gypsum and ettringite, with the latter found closer to the corrosion front. The conceptual model based on these findings clearly demonstrated the complex interactions among different chemical reactions, diffusion, and micro-structure changes.

  15. [Sanitary quality of water supply for human consumption in Campeche].

    Science.gov (United States)

    Isaac-Márquez, A P; Lezama-Dávila, C M; Ku-Pech, P P; Tamay-Segovia, P

    1994-01-01

    This paper presents data of a study undertaken to know the sanitary features of water supply (deep pools) for human consumption in the city of Campeche, Mexico. Levels of intestinal bacteria (total and fecal coliforms) were monitored, as well as heterotrophic plate counts and the surroundings of each deep pool were inspected. Each water supply was monitored three times from January to July, 1993 and presented unacceptable levels of heterotrophic plate counts and coliforms which is a strong evidence of fecal contamination of animal or human origin. These findings are a clear indication of unacceptable contamination of water supply for human consumption which requires an improvement and systematic inspection in order to provide good quality water to the population of Campeche.

  16. [Sanitary and nutritional control of the Catania school catering service].

    Science.gov (United States)

    Alonzo, Elena; Allegra, Antonio Dino; Cannizzaro, Virginia; Fardella, Maristella; La Carrubba, Rosanna

    2005-01-01

    Sanitary and nutritional control of meals distributed by school catering services is one of the institutional duties of the Food Hygiene and Nutrition Services (Servizi Igiene Alimenti e Nutrizione - SIAN) of the Local Health Units. In order to carry out this activity properly it is necessary to ask oneself beforehand what the main outcome of control activities should be. The answer to this question can only be that "proper nutrition is essential for healthy growth". Starting from this assumption, control activities performed along the entire chain of the scholastic catering service, starting from the final dish served at school up to the primary producer, were reviewed. The review was carried out by a team of multiprofessionals which included a physician, a prevention technician, a dietician, a biologist, an agronomist and a veterinarian. Preliminary results are extremely positive and show that the multidisciplinary integration of roles entrusted to the coordinators of SIAN is crucial to obtaining the best results.

  17. Sanitary Sewage Treatment with Jet Inner-loop Bioreactor

    Institute of Scientific and Technical Information of China (English)

    Wen Qin-xue; Chen Zhi-qiang; Lu Bing-nan; Wen Yan

    2004-01-01

    A jet inncr-loop bioreactor (JIBR) was used to treat synthetic sanitary sewage with low, medium and high COD load. The experimental resuhs show that it could meet discharge standard at 20-30 min of HRT (hydraulic retention time) for low COD concentration and 60-120 min of HRT for medium and high COD concentration. The maximal COD volume loading and COD sludye loading of 27kg·m-3·d-1 and 5 kg/d per kg MLSS were achieved respectively, that were 10-20 times higher than those of traditional wastewater treatment processes. The BOD5 removal efficiency was more than 90 % and NH1-N more than 85 %. The study on the activity showed that the oxygen consumption rate of the activated times higher than that of the SBR(Sequencing Batch Reactor)and thc dominant bacteria in jet inner-loop bioreactor was Pseudomonas species.

  18. Sanitary landfill groundwater quality assessment plan Savannah River Site

    Energy Technology Data Exchange (ETDEWEB)

    Wells, D.G.; Cook, J.W.

    1990-06-01

    This assessment monitoring plan has been prepared in accordance with the guidance provided by the SCDHEC in a letter dated December 7, 1989 from Pearson to Wright and a letter dated October 9, 1989 from Keisler to Lindler. The letters are included a Appendix A, for informational purposes. Included in the plan are all of the monitoring data from the landfill monitoring wells for 1989, and a description of the present monitoring well network. The plan proposes thirty-two new wells and an extensive coring project that includes eleven soil borings. Locations of the proposed wells attempt to follow the SCDHEC guidelines and are downgradient, sidegradient and in the heart of suspected contaminant plumes. Also included in the plan is the current Savannah River Site Sampling and Analysis Plan and the well construction records for all of the existing monitoring wells around the sanitary landfill.

  19. Global sensitivity analysis of an in-sewer process model for the study of sulfide-induced corrosion of concrete.

    Science.gov (United States)

    Donckels, B M R; Kroll, S; Van Dorpe, M; Weemaes, M

    2014-01-01

    The presence of high concentrations of hydrogen sulfide in the sewer system can result in corrosion of the concrete sewer pipes. The formation and fate of hydrogen sulfide in the sewer system is governed by a complex system of biological, chemical and physical processes. Therefore, mechanistic models have been developed to describe the underlying processes. In this work, global sensitivity analysis was applied to an in-sewer process model (aqua3S) to determine the most important model input factors with regard to sulfide formation in rising mains and the concrete corrosion rate downstream of a rising main. The results of the sensitivity analysis revealed the most influential model parameters, but also the importance of the characteristics of the organic matter, the alkalinity of the concrete and the movement of the sewer gas phase.

  20. Feasibility of sulfide control in sewers by reuse of iron rich drinking water treatment sludge.

    Science.gov (United States)

    Sun, Jing; Pikaar, Ilje; Sharma, Keshab Raj; Keller, Jürg; Yuan, Zhiguo

    2015-03-15

    Dosage of iron salt is the most commonly used method for sulfide control in sewer networks but incurs high chemical costs. In this study, we experimentally investigate the feasibility of using iron rich drinking water treatment sludge for sulfide control in sewers. A lab-scale rising main sewer biofilm reactor was used. The sulfide concentration in the effluent decreased from 15.5 to 19.8 mgS/L (without dosing) to below 0.7-2.3 mgS/L at a sludge dosing rate achieving an iron to total dissolved inorganic sulfur molar ratio (Fe:S) of 1:1, with further removal of sulfide possible by prolonging the reaction time. In fact, batch tests revealed an Fe consumption to sulfide removal ratio of 0.5 ± 0.02 (mole:mole), suggesting the possible occurrence of other reactions involving the removal of sulfide. Modelling revealed that the reaction between iron in sludge and sulfide has reaction orders of 0.65 ± 0.01 and 0.77 ± 0.02 with respect to the Fe and sulfide concentrations, respectively. The addition of sludge slightly increased the total chemical oxidation demand (tCOD) concentration (by approximately 12%) as expected, but decreased the soluble chemical oxidation demand (sCOD) concentration and methane formation by 7% and 20%, respectively. Some phosphate removal (13%) was also observed at the sludge dosing rate of 1:1 (Fe:S), which is beneficial to nutrient removal from the wastewater. Overall, this study suggests that dosing iron-rich drinking water sludge to sewers could be an effective strategy for sulfide removal in sewer systems, which would also reduce the sludge disposal costs for drinking water treatment works. However, its potential side-effects on sewer sedimentation and on the wastewater treatment plant effluent remain to be investigated.

  1. Kinetics of aerobic oxidation of volatile sulfur compounds in wastewater and biofilm from sewers

    DEFF Research Database (Denmark)

    Rudelle, Elise Alice; Vollertsen, Jes; Hvitved-Jacobsen, Thorkild

    2013-01-01

    -spot downstream of a force main and the other was a gravity sewer transporting young aerobic wastewater. The kinetics of VSC oxidation for both wastewater and suspended biofilm samples followed a first-order rate equation. The average values of the reaction rate constants demonstrated the following order......) and total inorganic sulfide, which have all been reported as the main constituents of foul sewer gas. Samples of wastewater and biofilm for the experiments were obtained from two locations that differed significantly with respect to the occurrence of VSCs. One location represented an odor hot...

  2. Shape Measurement of a Sewer Pipe Using a Mobile Robot with Computer Vision

    Directory of Open Access Journals (Sweden)

    Kikuhito Kawasue

    2013-01-01

    Full Text Available A mobile robot equipped with two lasers and a CCD camera for pipe inspection is proposed. Circular laser streaks that appeared on the inner surface of the pipe reveal the shape of the pipe. The 3D shape of a sewer pipe can be reconstructed considering the movement of the mobile robot along the pipe. Since the tilt of the mobile robot with respect to the axis of the pipe appears as the deformation between two circular streaks, the shape of a sewer pipe can be measured accurately, regardless of the tilt of the robot.

  3. [Sanitary regulation as part of health policy in Brazil: gaps and challenges].

    Science.gov (United States)

    Maia, Christiane; Guilhem, Dirce

    2016-05-01

    Objective To outline and discuss the main challenges for sanitary regulation contained in the federal-level Brazilian health policy. Methods For the present qualitative study, based on the analysis of public policies, information was collected from documents and interviews. Document analysis provided a historical overview of the insertion of sanitary regulation into the Brazilian health policy between 1999 and 2009 (first decade of existence of the national health surveillance agency, Anvisa). In addition, 13 interviews were carried out with actors selected for their historical, technical, or academic role in the field. Content analysis was used to define themes emerging from the materials analyzed with a focus on the "content" category, which refers to strategic and operational guidelines of policy programs, projects, initiatives, and normative framework. Results Content analysis revealed five themes that reflect the challenges to sanitary regulation in Brazil: 1) objects under regulation treated as isolated cases; 2) a Brazilian-specific model of sanitary regulation that is different from other international models; 3) ignorance regarding the role of sanitary surveillance in health care; 4) absence of an information system; and 5) absence of performance indicators and assessment tools. Conclusions Sanitary surveillance must have a mission that is disentangled from inspection tasks to become an effective instrument of health protection. For that, an information system that brings the National Sanitary Surveillance System together toward major objectives is essential. The adoption of tools for assessment of action is also required, with the establishment of adequate indicators.

  4. Comparing overflow and wave-overtopping induced breach initiation mechanisms in an embankment breach experiment

    Directory of Open Access Journals (Sweden)

    van Damme Myron

    2016-01-01

    Full Text Available As part of the SAFElevee project Delft University of Technology collabored with Flanders Hydraulics Research, and Infram B.V. in the preperation and execution of a full scale embankment breach experiment in November 2015. This breach experiment was performed on an 3.5m high embankment with a sand core and clay outer layer situated along the tidal river Scheldt in Belgium near Schellebelle. During the experiment a wave overtopping simulator and overflow simulator were used to initiate a breach. Both simulators were placed near the top of the waterside slope. The use of the simulators facilitated comparison between the effects of continueous overflow and the effects of intermittent wave overtopping. This paper presents the data collected during the experiment, describe the development of hypotheses on the failure processes using the latest insights, and comment on the failure initiation process of a grass covered flood embankment with a clay outer layer and a sandy core.

  5. Metamorphic Testing Integer Overflow Faults of Mission Critical Program: A Case Study

    Directory of Open Access Journals (Sweden)

    Zhanwei Hui

    2013-01-01

    Full Text Available For mission critical programs, integer overflow is one of the most dangerous faults. Different testing methods provide several effective ways to detect the defect. However, it is hard to validate the testing outputs, because the oracle of testing is not always available or too expensive to get, unless the program throws an exception obviously. In the present study, the authors conduct a case study, where the authors apply a metamorphic testing (MT method to detect the integer overflow defect and alleviate the oracle problem in testing critical program of Traffic Collision Avoidance System (TCAS. Experimental results show that, in revealing typical integer mutations, compared with traditional safety property testing method, MT with a novel symbolic metamorphic relation is more effective than the traditional method in some cases.

  6. A Generalized Loss Network Model with Overflow for Capacity Planning of a Perinatal Network

    CERN Document Server

    Asaduzzaman, Md

    2011-01-01

    We develop a generalized loss network framework for capacity planning of a perinatal network in the UK. Decomposing the network by hospitals, each unit is analyzed with a GI/G/c/0 overflow loss network model. A two-moment approximation is performed to obtain the steady state solution of the GI/G/c/0 loss systems, and expressions for rejection probability and overflow probability have been derived. Using the model framework, the number of required cots can be estimated based on the rejection probability at each level of care of the neonatal units in a network. The generalization ensures that the model can be applied to any perinatal network for renewal arrival and discharge processes.

  7. The Importance of Lake Overflow Floods for Early Martian Landscape Evolution: Insights From Licus Vallis

    Science.gov (United States)

    Goudge, T. A.; Fassett, C. I.

    2017-01-01

    Open-basin lake outlet valleys are incised when water breaches the basin-confining topography and overflows. Outlet valleys record this flooding event and provide insight into how the lake and surrounding terrain evolved over time. Here we present a study of the paleolake outlet Licus Vallis, a >350 km long, >2 km wide, >100 m deep valley that heads at the outlet breach of an approx.30 km diameter impact crater. Multiple geomorphic features of this valley system suggest it records a more complex evolution than formation from a single lake overflow flood. This provides unique insight into the paleohydrology of lakes on early Mars, as we can make inferences beyond the most recent phase of activity..

  8. Assessment of the effect of rainfall dynamics on the storm overflow performance

    Directory of Open Access Journals (Sweden)

    Szeląg Bartosz

    2016-06-01

    Full Text Available Assessment of the effect of rainfall dynamics on the storm overfl ow performance. This research study analyzes the effect of the rainfall characteristics (total and maximum 10-, 15- and 30-minute rainfall depth, its duration, the dry weather period on the performance of the emergency overflow weir located at the inflow to an existing treatment plant. The analyses used the numerical calculation results of the inflow hydrographs performed in the SWMM (Storm Water Management Model program on the basis of six-year-long rainfall measurement sequence. The obtained simulation results for the analysed catchment allowed for the performance of statistical analyses, which demonstrated that the volume of stormwater discharge, the maximum instantaneous flow and the share of stormwater volume discharged through the emergency overflow weir in relation to the total volume of the inflow hydrograph from the catchment are affected by the maximum 30-minute rainfall depth, whereas the discharge duration is affected by the depth of the catchment rainfall layer. Taking into account the results of statistical and hydraulic calculations it can be concluded that in the case of the analysed catchment the performance of the emergency overflow weir is affected to the greatest extent by the rainfall intensity distribution.

  9. Overflow dynamics and bottom water formation in the western Ross Sea: Influence of tides

    Science.gov (United States)

    Wang, Q.; Danilov, S.; Hellmer, H. H.; SchröTer, J.

    2010-10-01

    The tidal impact on overflow dynamics and bottom water production in the western Ross Sea is studied with the Finite Element Ocean Model, which allows embedding a mesh with 0.5 km resolution in a coarse resolution (30 km) setup without nesting. The simulated overflow properties inside and downstream of the western Ross Sea are described. The overflow exhibits pronounced variability at both daily and spring-neap tidal time scales in the western Ross Sea. Tides increase mixing over both the outer shelf and upper slope there. Plume jets are shaped by tidal currents at a bathymetric bend west of the Drygalski Trough mouth, descending rapidly and supplying the bottom water. A fraction of shelf water remains over the shelf and propagates westward from the Ross Sea, but it does not contribute significantly to bottom water formation because of energetic mixing over the upper slope. Compared to a simulation without tidal forcing, tides (with the major K1 and O1 constituents) increase the outflow rate over the continental slope off Cape Adare by about 70%. A set of sensitivity experiments show that the rate of bottom water production is not a monotonic function of the tidal currents amplitude. Tidal forcing with intermediate strength leads to the most efficient bottom water formation.

  10. Holocene multidecadal- to millennial-scale variations in Iceland-Scotland overflow and their relationship to climate

    Science.gov (United States)

    Mjell, Tor Lien; Ninnemann, Ulysses S.; Eldevik, Tor; Kleiven, Helga Kikki F.

    2015-05-01

    The Nordic Seas overflows are an important part of the Atlantic thermohaline circulation. While there is growing evidence that the overflow of dense water changed on orbital time scales during the Holocene, less is known about the variability on shorter time scales beyond the instrumental record. Here we reconstruct the relative changes in flow strength of Iceland-Scotland Overflow Water (ISOW), the eastern branch of the overflows, on multidecadal-millennial time scales. The reconstruction is based on mean sortable silt (SS>¯) from a sediment core on the Gardar Drift (60°19'N, 23°58'W, 2081 m). Our SS>¯ record reveals that the main variance in ISOW vigor occurred on millennial time scales (1-2 kyr) with particularly prominent fluctuations after 8 kyr. Superimposed on the millennial variability, there were multidecadal-centennial flow speed fluctuations during the early Holocene (10-9 kyr) and one prominent minimum at 0.9 kyr. We find a broad agreement between reconstructed ISOW and regional North Atlantic climate, where a strong (weak) ISOW is generally associated with warm (cold) climate. We further identify the possible contribution of anomalous heat and freshwater forcing, respectively, related to reconstructed overflow variability. We infer that ocean poleward heat transport can explain the relationship between regional climate and ISOW during the middle to late Holocene, whereas freshwater input provides a possible explanation for the reduced overflow during early Holocene (8-10 kyr).

  11. Sulfide-iron interactions in domestic wastewater from a gravity sewer

    NARCIS (Netherlands)

    Nielsen, A.H.; Lens, P.N.L.; Vollertsen, J.; Hvitved-Jacobsen, Th.

    2005-01-01

    Interactions between iron and sulfide in domestic wastewater from a gravity sewer were investigated with particular emphasis on redox cycling of iron and iron sulfide formation. The concentration ranges of iron and total sulfide in the experiments were 0.4-5.4 mg Fe L-1 and 0-5.1 mg S L-1, respectiv

  12. Assessment of the effects of greywater reuse on gross solids movement in sewer systems.

    Science.gov (United States)

    Penn, R; Schütze, M; Friedler, E

    2014-01-01

    Onsite greywater reuse (GWR) and installation of water-efficient toilets (WETs) reduce urban freshwater demand and thus enhance urban water use sustainability. Research on GWR and WETs has generally overlooked their potential effects on municipal sewer systems: GWR and WETs affect the flow regime in sewers, and consequently also influence gross solids transport. To asses these impacts, a gross solids transport model was developed. The model is based on approaches found in the literature. Hydrodynamic calculations of sewage flow were performed using the SIMBA6 simulator and then used for the gross solid movement models. Flow characteristics in the up- and downstream sections of the sewer network differ. Therefore different approaches were used to model solids movement in each of these two parts. Each model determines whether a solid moves as a result of a momentary sewage flow, and if it moves, calculation of its velocity is possible. The paper shows the adoption and implementation of two gross solids transport models using SIMBA6 and depicts the results of the effects of various GWR and WET scenarios on gross solids movement in sewers for a real case study in Israel.

  13. Modelling Illicit Drug Fate in Sewers for Wastewater-Based Epidemiology

    DEFF Research Database (Denmark)

    Ramin, Pedram

    prevailing in sewers and were operated over 14 months. Abiotic transformation (e.g., hydrolysis) was also evaluated using mineral water and sorption to suspended solids and biofilms were additionally assessed. Overall, two sets of experiments were performed and used for model calibration and model validation...

  14. Analyzing hydrocarbons in sewer to help in PAH source apportionment in sewage sludges.

    Science.gov (United States)

    Mansuy-Huault, Laurence; Regier, Annette; Faure, Pierre

    2009-05-01

    A multi-molecular approach for polycyclic aromatic hydrocarbons (PAH) source apportionment in sewage sludge was tested. Three simple catchment areas with corresponding wastewater treatment plants (WWTP) were chosen. Sewage sludges of these WWTPs chronically exceeded the French guide values for PAHs. Aliphatic and aromatic hydrocarbons were quantified in sediments or wastewater suspended particulate matter sampled in different locations of the sewer as well as in sewage sludge. Various molecular indices including PAH ratios were calculated. The results showed that the ratios calculated from sewage sludge analyses provided a rather unspecific hydrocarbon fingerprint where combustion input appear as the main PAH sources. The complexity of the inputs as well as degradation occurring during wastewater treatment prevent any detailed diagnosis. Coupled to the analyses of samples collected in the sewer, the multi-molecular approach becomes more efficient especially for the identification of specific petroleum inputs such as fuel or used lubricating oils which can be important PAH sources. Indeed, the sampling in the sewer allows a spatial screening of the hydrocarbon inputs and facilitates the PAH source apportionment by avoiding the dilution of specific inputs with the whole wastewater inputs and by limiting the degradation of the molecular fingerprint that could occur during transfer and treatment in the WWTP. Then, the combination of PAH ratios and aliphatic distribution analyses is a very valuable approach that can help in sewer and WWTP management.

  15. Control of Sewer systems and Wastewater treatment plants using pollutant concentration profiles

    DEFF Research Database (Denmark)

    Bechmann, Henrik; Nielsen, Marinus K.; Madsen, Henrik

    1998-01-01

    On-line measurements of pollutants in the wastewater combined with grey-box modelling are used to estimate the amount of deposits in the sewer system. The pollutant mass flow at the wastewater treatment plant is found to consist of a diurnal profile minus the deposited amount of pollutants...

  16. Reliability of adaptive multivariate software sensors for sewer water quality monitoring

    DEFF Research Database (Denmark)

    Vezzaro, Luca; Mikkelsen, Peter Steen

    2015-01-01

    This study investigates the use of a multivariate approach, based on Principal Component Analysis PCA), as software sensor for fault detection and reconstruction of missing measurements in on-line monitoring of sewer water quality. The analysis was carried out on a 16-months dataset of five...

  17. Controlling chemical dosing for sulfide mitigation in sewer networks using a hybrid automata control strategy.

    Science.gov (United States)

    Liu, Yiqi; Ganigué, Ramon; Sharma, Keshab; Yuan, Zhiguo

    2013-01-01

    Chemicals such as magnesium hydroxide (Mg(OH)2) and iron salts are widely used to control sulfide-induced corrosion in sewer networks composed of interconnected sewer pipe lines and pumping stations. Chemical dosing control is usually non-automatic and based on experience, thus often resulting in sewage reaching the discharge point receiving inadequate or even no chemical dosing. Moreover, intermittent operation of pumping stations makes traditional control theory inadequate. A hybrid automata-based (HA-based) control method is proposed in this paper to coordinate sewage pumping station operations by considering their states, thereby ensuring suitable chemical concentrations in the network discharge. The performance of the proposed control method was validated through a simulation study of a real sewer network using real sewage flow data. The physical, chemical and biological processes were simulated using the well-established SeweX model. The results suggested that the HA-based control strategy significantly improved chemical dosing control performance and sulfide mitigation in sewer networks, compared to the current common practice.

  18. Quality of visual sewer inspection data: The need for a new coding system?! (poster)

    NARCIS (Netherlands)

    Dirksen, J.; Van der Steen, A.; Langeveld, J.G.; Clemens, F.H.L.R.

    2013-01-01

    Previous research learned that the reproducibility of visual sewer inspection data is poor (Dirksen et al.). Further research by Arjan et al. showed that the applied coding system has a major influence on the reproducibility. The aim of this study was to give relevant suggestions to improve the qual

  19. Microbiologically Induced Corrosion of Concrete and Protective Coatings in Gravity Sewers

    Institute of Scientific and Technical Information of China (English)

    Marjorie Valix; Diyana Zamri; Hiro Mineyama; Wai Hung Cheung; Jeffrey Shi; Heri Bustamante

    2012-01-01

    Microbiologically induced corrosion of concrete (MICC) and its protective coatings has a high eco-nomic impact on sewer maintenance and rehabilitation. A better understanding of the micro-organisms and the bio- genie acids that are generated in the sewer is essential in controlling the corrosion of concrete pipes and protective coatings. The role of succession of micro-organisms growth in the corrosion of concrete and protective coatings was evaluated in this study. Examination of various sewer pipe materials exhibiting various extents of degradation, including concrete, cement based and epoxy based coating revealed the presence of both organic and biogenic sulphuric acids. This reflects the activity of fungi and the thiobacilli strains. Organism growth and metabolism were strongly related to the substrate pH. Fungi were found to grow and metabolise organic acids at pH from 2.0-8.0. Whilst the thiobacilli strains grew and generated sulohuric acids at oH below 3.0. The successive growth of the organisms provides an impgrtant bearing in deyeloping improved strateegies.to better manage sewers.

  20. Sulfide-iron interactions in domestic wastewater from a gravity sewer

    NARCIS (Netherlands)

    Nielsen, A.H.; Lens, P.N.L.; Vollertsen, J.; Hvitved-Jacobsen, Th.

    2005-01-01

    Interactions between iron and sulfide in domestic wastewater from a gravity sewer were investigated with particular emphasis on redox cycling of iron and iron sulfide formation. The concentration ranges of iron and total sulfide in the experiments were 0.4-5.4 mg Fe L-1 and 0-5.1 mg S L-1, respectiv

  1. Determination of kinetics and stoichiometry of chemical sulfide oxidation in wastewater of sewer networks

    DEFF Research Database (Denmark)

    Nielsen, A.H.; Vollertsen, Jes; Hvitved-jacobsen, Thorkild

    2003-01-01

    A method for determination of kinetics and stoichiometry of chemical sulfide oxidation by dissolved oxygen (DO) in wastewater is presented. The method was particularly developed to investigate chemical sulfide oxidation in wastewater of sewer networks at low DO concentrations. The method is based...

  2. Corrosion of concrete sewers--the kinetics of hydrogen sulfide oxidation.

    Science.gov (United States)

    Vollertsen, Jes; Nielsen, Asbjørn Haaning; Jensen, Henriette Stokbro; Wium-Andersen, Tove; Hvitved-Jacobsen, Thorkild

    2008-05-01

    Hydrogen sulfide absorption and oxidation by corroding concrete surfaces was quantified in a test rig consisting of 6 concrete pipes operated under sewer conditions. The test rig was placed in an underground sewer monitoring station with access to fresh wastewater. Hydrogen sulfide gas was injected into the pipe every 2nd hour to peak concentrations around 1000 ppm. After some months of operation, the hydrogen sulfide became rapidly oxidized by the corroding concrete surfaces. At hydrogen sulfide concentrations of 1000 ppm, oxidation rates as high as 1 mg S m(-2) s(-1) were observed. The oxidation process followed simple nth order kinetics with a process order of 0.45-0.75. Extrapolating the results to gravity sewer systems showed that hydrogen sulfide oxidation by corroding concrete is a fast process compared to the release of hydrogen sulfide from the bulk water, resulting in low gas concentrations compared with equilibrium. Balancing hydrogen sulfide release with hydrogen sulfide oxidation at steady state conditions demonstrated that significant corrosion rates--several millimeters of concrete per year--can potentially occur at hydrogen sulfide gas phase concentrations well below 5-10 ppm. The results obtained in the study advances the knowledge on prediction of sewer concrete corrosion and the extent of odor problems.

  3. High-throughput amplicon sequencing reveals distinct communities within a corroding concrete sewer system.

    Science.gov (United States)

    Cayford, Barry I; Dennis, Paul G; Keller, Jurg; Tyson, Gene W; Bond, Philip L

    2012-10-01

    Microbially induced concrete corrosion (MICC) is an important problem in sewers. Here, small-subunit (SSU) rRNA gene amplicon pyrosequencing was used to characterize MICC communities. Microbial community composition differed between wall- and ceiling-associated MICC layers. Acidithiobacillus spp. were present at low abundances, and the communities were dominated by other sulfur-oxidizing-associated lineages.

  4. Predicting the Probability of Failure of Cementitious Sewer Pipes Using Stochastic Finite Element Method

    Directory of Open Access Journals (Sweden)

    Amir M. Alani

    2015-06-01

    Full Text Available In this paper, a stochastic finite element method (SFEM is employed to investigate the probability of failure of cementitious buried sewer pipes subjected to combined effect of corrosion and stresses. A non-linear time-dependant model is used to determine the extent of concrete corrosion. Using the SFEM, the effects of different random variables, including loads, pipe material, and corrosion on the remaining safe life of the cementitious sewer pipes are explored. A numerical example is presented to demonstrate the merit of the proposed SFEM in evaluating the effects of the contributing parameters upon the probability of failure of cementitious sewer pipes. The developed SFEM offers many advantages over traditional probabilistic techniques since it does not use any empirical equations in order to determine failure of pipes. The results of the SFEM can help the concerning industry (e.g., water companies to better plan their resources by providing accurate prediction for the remaining safe life of cementitious sewer pipes.

  5. Transformation of AgCl nanoparticles in a sewer system--A field study.

    Science.gov (United States)

    Kaegi, Ralf; Voegelin, Andreas; Sinnet, Brian; Zuleeg, Steffen; Siegrist, Hansruedi; Burkhardt, Michael

    2015-12-01

    Silver nanoparticles (Ag-NP) are increasingly used in consumer products and their release during the use phase may negatively affect aquatic ecosystems. Research efforts, so far, have mainly addressed the application and use of metallic Ag(0)-NP. However, as shown by recent studies on the release of Ag from textiles, other forms of Ag, especially silver chloride (AgCl), are released in much larger quantities than metallic Ag(0). In this field study, we report the release of AgCl-NP from a point source (industrial laundry that applied AgCl-NP during a piloting phase over a period of several months to protect textiles from bacterial regrowth) to the public sewer system and investigate the transformation of Ag during its transport in the sewer system and in the municipal wastewater treatment plant (WWTP). During the study period, the laundry discharged ~85 g of Ag per day, which dominated the Ag loads in the sewer system from the respective catchment (72-95%) and the Ag in the digested WWTP sludge (67%). Combined results from electron microscopy and X-ray absorption spectroscopy revealed that the Ag discharged from the laundry to the sewer consisted of about one third AgCl and two thirds Ag2S, both forms primarily occurring as nanoparticles with diameters95%). Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Monitoring the Startup of a Sacrificial Concrete Sewer for Odor Control

    DEFF Research Database (Denmark)

    Nielsen, Asbjørn Haaning; Vollertsen, Jes

    2014-01-01

    to reduce hydrogen sulphide gas (H2S (g)) concentrations in the sewer headspace. After being in operation for approximately half a year, the system was able to maintain average H2S (g) levels of less than 1 ppmv at the downstream end, which is the first place air can escape. The daily maximum H2S (g) levels...

  7. Resistance to anticoagulants in rats (Rattus norvegicus) in sewers in an urban area

    DEFF Research Database (Denmark)

    Lodal, Jens

    2007-01-01

    . Therefore a project for studying resistance levels in sewer rats was undertaken in an urban area of a municipality in southern Zealand from where surface rats had been tested during the foregoing years. Rats resistant to difenacoum represented the highest level of resistance in the municipality. Rats were...

  8. Transformation of AgCl nanoparticles in a sewer system — A field study

    Energy Technology Data Exchange (ETDEWEB)

    Kaegi, Ralf, E-mail: ralf.kaegi@eawag.ch [Eawag, Swiss Federal Institute of Aquatic Science and Technology, Überlandstrasse 133, 8600 Dübendorf (Switzerland); Voegelin, Andreas; Sinnet, Brian [Eawag, Swiss Federal Institute of Aquatic Science and Technology, Überlandstrasse 133, 8600 Dübendorf (Switzerland); Zuleeg, Steffen [KUSTER + HAGER Group, Oberstrasse 222, 9014 St. Gallen (Switzerland); Siegrist, Hansruedi [Eawag, Swiss Federal Institute of Aquatic Science and Technology, Überlandstrasse 133, 8600 Dübendorf (Switzerland); Burkhardt, Michael [HSR University of Applied Sciences, Institute of Environmental and Process Engineering (UMTEC), Oberseestrasse 10, 8640 Rapperswil (Switzerland)

    2015-12-01

    Silver nanoparticles (Ag-NP) are increasingly used in consumer products and their release during the use phase may negatively affect aquatic ecosystems. Research efforts, so far, have mainly addressed the application and use of metallic Ag(0)-NP. However, as shown by recent studies on the release of Ag from textiles, other forms of Ag, especially silver chloride (AgCl), are released in much larger quantities than metallic Ag(0). In this field study, we report the release of AgCl-NP from a point source (industrial laundry that applied AgCl-NP during a piloting phase over a period of several months to protect textiles from bacterial regrowth) to the public sewer system and investigate the transformation of Ag during its transport in the sewer system and in the municipal wastewater treatment plant (WWTP). During the study period, the laundry discharged ~ 85 g of Ag per day, which dominated the Ag loads in the sewer system from the respective catchment (72–95%) and the Ag in the digested WWTP sludge (67%). Combined results from electron microscopy and X-ray absorption spectroscopy revealed that the Ag discharged from the laundry to the sewer consisted of about one third AgCl and two thirds Ag{sub 2}S, both forms primarily occurring as nanoparticles with diameters < 100 nm. During the 800 m transport in the sewer channel to the nearby WWTP, corresponding to a travel time of ~ 30 min, the remaining AgCl was transformed into nanoparticulate Ag{sub 2}S. Ag{sub 2}S-NP also dominated the Ag speciation in the digested sludge. In line with results from earlier studies, the very low Ag concentrations measured in the effluent of the WWTP (< 0.5 μg L{sup −1}) confirmed the very high removal efficiency of Ag from the wastewater stream (> 95%). - Highlights: • First field study on the transformation of AgCl nanoparticles released from a point source into the municipal sewer system. • Transformation of AgCl-NP into Ag{sub 2}S already occurred during 30-min transport in the

  9. Multiculturalità, “diritti” e differenziazioni giuridiche: il caso dei trattamenti sanitari

    Directory of Open Access Journals (Sweden)

    Giancarlo Anello

    2013-05-01

    Full Text Available Contributo sottoposto a valutazione SOMMARIO: 1. Premessa - 2. Multiculturalità, “diritti” e trattamenti sanitari - 3. Alcune problematiche del cd. testamento biologico in una prospettiva interculturale - 4. Conclusioni.

  10. Research and development of intelligent controller for high-grade sanitary ware

    Science.gov (United States)

    Bao, Kongjun; Shen, Qingping

    2013-03-01

    With the social and economic development and people's living standards improve, more and more emphasis on modern society, people improve the quality of family life, the use of intelligent controller applications in high-grade sanitary ware physiotherapy students. Analysis of high-grade sanitary ware physiotherapy common functions pointed out in the production and use of the possible risks, proposed implementation of the system hardware and matching, given the system software implementation process. High-grade sanitary ware physiotherapy intelligent controller not only to achieve elegant and beautiful, simple, physical therapy, water power, deodorant, multi-function, intelligent control, to meet the consumers, the high-end sanitary ware market, strong demand, Accelerate the enterprise product Upgrade and improve the competitiveness of enterprises.

  11. The SWOT Analysis of a Romanian Post-Sanitary Institution in Romania

    Directory of Open Access Journals (Sweden)

    Cristina Iorga

    2016-01-01

    Starting from a comprehensive research (literature review, the paper proposes the realization of aSWOT analysis within a post-sanitary school, which aims at emphasizing the main advantages of apost-secondary schools perceived by students and discovering major development opportunities forthe quality of services offered by it, as a premise of the improvement of the sanitary schools, andthus, the health system in Romania.

  12. Benjarong Sanitary Ware: Design and development for commerce in Samut Sakhon Province, Thailand

    Directory of Open Access Journals (Sweden)

    Wanchai Sama

    2015-08-01

    Full Text Available This investigation has three primary aims: 1 to study the traditional knowledge of Benjarong in Samut Sakhon Province; 2 to study designs and the production process of Benjarong sanitary ware in Samut Sakhon Province; 3 to develop Benjarong sanitary ware for commerce in Samut Sakhon Province. The research area for this investigation was purposively selected as Samut Sakhon Province. Data was gathered by document study, survey, participant and non-participant observation, structured and non-structured interview, focus group discussion and workshop. Results show that Benjarong sanitary products have been inherited from generation to generation in Samut Sakhon Province and continue to provide local jobs. Benjarong sanitary ware production uses a high budget because of the high price of colour inks, gold and electricity, so there are problems securing adequate funding. There are also problems with the management process and a lack of expert craftsmen to write and design modern patterns in harmony with contemporary art and Thai social identity. Moreover, many Thai people do not realize the value of cultural heritage and Benjarong inheritance is at risk. Benjarong sanitary ware can reflect local knowledge and traditional handicrafts. The researchers propose patterns for three types of Benjarong sanitary ware: washbasins, wall tiles and soap ledges. Development of these products will increase functionality and aesthetics, whilst maintaining Thai heritage.

  13. Unpleasantness and physiological responses in using sanitary napkins.

    Science.gov (United States)

    Park, Mi-Kyong; Watanuki, Shigeki

    2005-01-01

    This study investigated the physiological and psychological effects of sanitary napkins (SN) on women in hemorrhage treatment during the menstrual phase. Mesh and non-woven napkins were employed, and the effects were studied during the follicular and menstrual phases; mesh SN presented a higher textural surface-roughness. In both phases, the increases in systolic and diastolic blood pressure were significantly dependent on the application intervals. The low-frequency component of systolic blood pressure variability significantly increased, while the salivary secretion rate decreased with the use of mesh SN during the follicular phase compared with non-woven SN. In addition, the heart rate during the menstrual phase significantly increased in subjects after the replacement of mesh SN compared with non-woven SN. In cases of wearing the unpleasant mesh SN, electroencephalography (EEG) manifested bilateral enhancements in beta and alpha2 waves in the frontal areas increased arousal level during both phases. From the above findings, napkin use increased physiological loading and wearing napkins with higher textural surface-roughness tended to increase activities of the autonomic nervous system and brain arousal level.

  14. RATES OF GASTROINTESTINAL ILLNESS AMONG AREAS IMPACTED BY COMBINED SEWER FACILITIES: ANALYSIS OF MASSACHUSETTS DATA, 2003-2007

    Science.gov (United States)

    Previous studies have reported a temporal association between heavy rainfall and gastrointestinal infection (GI). Combined sewer systems (CSSs), which are present in many urban areas in the US, were designed to collect rainwater runoff, domestic sewage, and industrial wastewater ...

  15. Scanned Hardcopy Maps, All Engineering hanging files: sewer, water, construction plans, and subdivisions, Published in 2008, City of Hutchinson.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Scanned Hardcopy Maps dataset, was produced all or in part from Hardcopy Maps information as of 2008. It is described as 'All Engineering hanging files: sewer,...

  16. 78 FR 9908 - Notice of Availability of the Draft Issuance of the Small Municipal Separate Storm Sewer System...

    Science.gov (United States)

    2013-02-12

    ... sewer systems in municipalities such as systems at military bases, large hospital or prison complexes... meet the MEP standard. The iterative process of MEP consists of a municipality developing a...

  17. Identification of controlling factors for the initiation of corrosion of fresh concrete sewers.

    Science.gov (United States)

    Jiang, Guangming; Sun, Xiaoyan; Keller, Jurg; Bond, Philip L

    2015-09-01

    The development of concrete corrosion in new sewer pipes undergoes an initiation process before reaching an active corrosion stage. This initiation period is assumed to last several months to years but the key factors affecting the process, and its duration, are not well understood. This study is therefore focused on this initial stage of the corrosion process and the effect of key environmental factors. Such knowledge is important for the effective management of corrosion in new sewers, as every year of life extension of such systems has a very high financial benefit. This long-term (4.5 year) study has been conducted in purpose-built corrosion chambers that closely simulated the sewer environment, but with control of three key environmental factors being hydrogen sulfide (H2S) gas phase concentration, relative humidity and air temperature. Fresh concrete coupons, cut from an industry-standard sewer pipe, were exposed to the corrosive conditions in the chambers, both in the gas phase and partially submerged in wastewater. A total of 36 exposure conditions were investigated to determine the controlling factors by regular retrieval of concrete coupons for detailed analysis of surface pH, sulfur compounds (elemental sulfur and sulfate) and concrete mass loss. Corrosion initiation times were thus determined for different exposure conditions. It was found that the corrosion initiation time of both gas-phase and partially-submerged coupons was positively correlated with the gas phase H2S concentration, but only at levels of 10 ppm or below, indicating that sulfide oxidation rate rather than the H2S concentration was the limiting factor during the initiation stage. Relative humidity also played a role for the corrosion initiation of the gas-phase coupons. However, the partially-submerged coupons were not affected by humidity as these coupons were in direct contact with the sewage and hence did have sufficient moisture to enable the microbial processes to proceed. The

  18. [Design of software and hardware complex of automated systems for the management of the State Sanitary and Epidemiological Surveillance].

    Science.gov (United States)

    Mel'nichenko, P I; Muzychenko, F V; Malinovskiĭ, A A; Leont'ev, L Iu; Ustiukhin, N V

    2005-05-01

    A new information system (IS) - the software and hardware complex for controlling the state sanitary-and-epidemiological inspection (SSEI) was created. The system represents the aggregate of automated working places of RF MD chief state sanitary physician arid specialists from the department of state sanitary-and-epidemiological inspection of the Main Military Medical Headquarters. They interact through communications with working places of specialists from SSEI Main Center, chief state sanitary physicians from the Armed Forces, military districts (fleets) and RFAF CSSEI. The special software provides automation of the following technological processes: operative sanitary-and epidemiological and epidemiological monitoring; the epidemiological analysis of infectious diseases; the evaluation of quality and efficiency of sanitary-and epidemiological work. At present the complex works in the regime of experimental exploitation when the adjustment of communications and special software is performed.

  19. Spatial localization and mesoscale modulation of mixing and transformation of the Denmark Strait Overflow

    Science.gov (United States)

    Koszalka, Inga; Haine, Thomas; Magaldi, Marcello

    2015-04-01

    The Denmark Strait Overflow (DSO) is a major export route for dense waters from the Nordic Seas forming the North Atlantic Deep Water, an important element of the climate system. Mixing processes in the Irminger Basin determine volume transport and properties of the DSO but are poorly resolved by sparse observations which hinders development of DSO mixing parameterizations in global circulation models (GCMs). We employ a high resolution circulation model (horizontal grid spacing of 2km and 210 levels in the vertical) to investigate transformation and mixing in the DSO in the Irminger Basin and quantify the effect of mesoscale (10-100km) flows unresolved by GCMs. Both the warming rate derived from model Lagrangian particles and the Eulerian eddy temperature flux divergence show elevated values in about a 200km long and 50km wide corridor downstream of the Denmark Strait sill and between the shelf break and the 2000m isobath. In this region, the DSO warms by about 1K, which constitutes most of the transformation along the entire 700km pathway in the Irminger Basin. The horizontal and vertical mixing is modulated by dense water boluses and overlying cyclonic eddies that propagate together through the Irminger Basin (`beddies'). The passage of beddies increase the squared vertical shear of horizontal velocity by a factor of 3, correspond to increase in the vertical velocity by ten times and double the eddy heat flux divergence leading to a warming of the bottom (densest) waters and a cooling of the interface layer of the overflow plume and the ambient water above. There is a clear correlation between the speed in the nose of the plume, the eddy kinetic energy and the vertical shear in the horizontal flow. The modulation of mixing by the mesoscale variability and the attendant mixing localization should be included in future overflow parameterizations in global circulation models. A targeted field campaign to empirically test these conjectures is another high priority.

  20. What Security Questions Do Developers Ask? A Large-Scale Study of Stack Overflow Posts

    Institute of Scientific and Technical Information of China (English)

    Xin-Li Yang; David Lo; Xin Xia; Zhi-Yuan Wan; Jian-Ling Sun

    2016-01-01

    Security has always been a popular and critical topic. With the rapid development of information technology, it is always attracting people’s attention. However, since security has a long history, it covers a wide range of topics which change a lot, from classic cryptography to recently popular mobile security. There is a need to investigate security-related topics and trends, which can be a guide for security researchers, security educators and security practitioners. To address the above-mentioned need, in this paper, we conduct a large-scale study on security-related questions on Stack Overflow. Stack Overflow is a popular on-line question and answer site for software developers to communicate, collaborate, and share information with one another. There are many different topics among the numerous questions posted on Stack Overflow and security-related questions occupy a large proportion and have an important and significant position. We first use two heuristics to extract from the dataset the questions that are related to security based on the tags of the posts. And then we use an advanced topic model, Latent Dirichlet Allocation (LDA) tuned using Genetic Algorithm (GA), to cluster different security-related questions based on their texts. After obtaining the different topics of security-related questions, we use their metadata to make various analyses. We summarize all the topics into five main categories, and investigate the popularity and difficulty of different topics as well. Based on the results of our study, we conclude several implications for researchers, educators and practitioners.