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Nutrient fluxes in stream basins need to be controlled to achieve good water quality status. In stream basins with intensive agricultural activities, nutrients predominantly come from diffuse sources. Therefore, best management practices (BMPs) are increasingly implemented to reduce nutrient input to streams. The objective of this study is to evaluate the impact of vegetated filter strip (VFS) application as an agricultural BMP. For this purpose, SWAT is chosen, a semi-distributed water quality assessment model that works at the watershed scale, and applied on the Nif stream basin, a small-sized basin in Western Turkey. The model is calibrated with an automated procedure against measured monthly discharge data. Nutrient loads for each sub-basin are estimated considering basin-wide data on chemical fertilizer and manure usage, population data for septic tank effluents and information about the land cover. Nutrient loads for 19 sub-basins are predicted on an annual basis. Average total nitrogen and total phosphorus loads are estimated as 47.85 t/yr and 13.36 t/yr for the entire basin. Results show that VFS application in one sub-basin offers limited retention of nutrients and that a selection of 20-m filter width is most effective from a cost-benefit perspective. [ABSTRACT FROM AUTHOR]

Water quality trading (WQT) could be an innovative policy to incentivize farmers to implement best management practices (BMPs) for their activities. This study focused on assessment of involving unregulated agricultural nonpoint sources (NPS) into the WQT market in Gharesoo watershed in the west of Iran. It also proposes a methodology to determine location-based trading ratios as well as environmental penalty cost to achieve a more well-designed market structure. Trading activities in different scenarios were described by trading volume (TV), participation rate (PR), total exchanged value (TEV), and other market parameters in order to achieve a better comparison of market performance. Results showed that, by applying NPS to the Gharesoo watershed, total phosphorous (TP) trading market could increase TV, PR, and TEV up to 11, 1.7 and 7.5 times, respectively, depending on which level of BMPs are implemented by them. Additionally, it could save 29% of the total cost of implementing a TP total maximum daily load in this watershed compared to the 'command and control' approach. Furthermore, the agricultural sector could profit by $5.49 million (or $75/ha) by choosing solutions such as terrace systems and filter strips to register into the market. This profit can be allocated to the development of new agricultural technologies. [ABSTRACT FROM AUTHOR]

Compact filter systems, which are installed to significantly reduce the load of pollutants from road runoff, are very promising treatments for urban runoff. The objective of this research was to evaluate the effectiveness of activated carbon, activated lignite, zero valent iron, exfoliated graphite, amorphous ferric hydroxide, and activated alumina at removing petrol hydrocarbons from synthetic road runoff. Therefore, the kinetics and the equilibrium adsorption of petrol hydrocarbons onto these adsorbents were investigated using column adsorption experiments at levels ranging from 100 to 42 g L-1. Of the tested adsorbents, exfoliated graphite is the most effective with a maximum adsorption capacity for petrol hydrocarbons of 3,850 mg g-1. The experimental equilibrium data are fitted to the Freundlich and Langmuir models. [ABSTRACT FROM AUTHOR]

This study reports on 6 years of performance monitoring of stormwater hydrodynamic separators in Korean urban catchments. One hundred and thirty-seven storm events were monitored in four hydrodynamic separators of two different types from 2006 to 2012. Mean values of the event average removal efficiencies of total suspended solids (TSS) for the four hydrodynamic separators were 43.69, 8.54, 42.84, and 14.35% with corresponding mean values of the event average surface overflow rates of 28.62, 40.07, 16.02, and 38.81 m/h, respectively. The low TSS removal efficiency was due to the high instantaneous surface overflow rates frequently occurring throughout a storm event and the abundance of fine particle fractions in the inflow (median particle diameter <75 μm). The Weibull function was used to simulate particle size distribution (PSD) in the runoff and the simulated PSD functions were further applied to the discrete settling theory to develop curves of TSS removal efficiency, as a function of surface overflow rate and median particle size of the inflow. The developed curves should be useful in determining the design peak flow rate and the size of a hydrodynamic separator for a stated goal of TSS removal efficiency. [ABSTRACT FROM AUTHOR]

The use of sustainable drainage systems (SuDS) or best management practice is becoming increasingly common. However, rather than adopting the preferred 'treatment train' implementation, many developments opt for end-of-pipe control ponds. This paper discusses the use of SuDS in series to form treatment trains and compares their potential performance and effectiveness with end-of-pipe solutions. Land-use, site and catchment characteristics have been used alongside up-todate guidance, Infoworks CS and MUSIC to determine whole-life-costs, land-take, water quality and quantity for different SuDS combinations. The results presented show that the use of a treatment train allows approaches differing from the traditional use of single SuDS, either source or 'end-of pipe', to be proposed to treat and attenuate runoff. The outcome is a more flexible solution where the footprint allocated to SuDS, costs and water quality can be managed differently to fully meet stakeholder objectives. [ABSTRACT FROM AUTHOR]

The best management practices (BMPs) for control of urban stormwater pollution are evaluated to remove solid particles containing various pollutants. Currently, most storm runoff treatment devices using primary pollutant removal mechanism are applied to storm water since most pollutants in runoff are associated with the solid particulates. A hydrodynamic separator is a storm water treatment device using centrifugal motion which separates solids pollution from runoff. In this study, the velocity flow field and particle tracking of hydrodynamic separator were investigated using anthracite as a computational fluid dynamics (CFD) model particle. The Fluent 6.3.26 CFD program was used to predict the solid particles removal efficiency for various parameters such as particle size, surface loading rate, and the ratio of underflow to overflow. The velocity flow field in a hydrodynamic stormwater separator (HDS) has been simulated using CFD RNG κ-ϵ model. Modeling results for the removal efficiency of HDS were similar with the results obtained from experimental measurements of laboratory scale HDS. These results showed that the simulated velocity field was useful to interpret the behavior of flow in the hydrodynamic separator. The results obtained from particle tracking can be applied to predict the separation efficiency. [ABSTRACT FROM AUTHOR]

Modelling the removal of micropollutants (MPs) in stormwater treatment systems is essential in a context that is characterized by a general lack of measurements. This paper presents an innovative dynamic model for the prediction of the removal of MPs in stormwater treatment systems (Stormwater Treatment Unit model for Micro Pollutants-STUMP). The model, based on a conceptual model of two-compartment (water and sediment) serial Continuous Stirred-Tank Reactors (CSTRs), can predict the fate of MPs based on their inherent properties, which are often the only information available regarding this kind of substances. The flexible structure of the model can be applied to a wide range of treatment units and substances. Based on the most relevant removal processes (settling, volatilization, sorption, biodegradation, and abiotic degradation), the model allows the dynamic simulation of the MP behaviour in the different compartments of stormwater treatment systems. The model was tested for heavy metals (copper and zinc) and organic substances (benzene and di(2-ethylhexyl)phthalate). The results show that volatilization plays a big role for removal of benzene while the removal of substances with high sorption capacity is mainly driven by settling. The model was proven to be able to predict the importance of the various fate processes for selected substances with different inherent properties. A thorough assessment of the influence of the various fate process parameters will allow a reliable assessment of the treatment performances for a wide range of MPs. [ABSTRACT FROM AUTHOR]

The use of Sustainable Drainage Systems (SuDS) or Best Management Practice (BMP) is becoming increasingly common. However, rather than adopting the preferred "treatment train" implementation, many developments opt for end of pipe control ponds. This paper discusses the use of SuDS in series to form treatment trains and compares their potential performance and effectiveness with end of pipe solutions. Land-use, site and catchment characteristics have been used alongside up-to-date guidance, Infoworks CS and MUSIC to determine whole-life-costs, land-take, water quality and water quantity for different SuDS combinations. The results presented show that the use of a treatment train allows approaches differing from the traditional use of single SuDS, either source or "end of pipe", to be proposed to treat and attenuate runoff. The outcome is a more flexible solution where the footprint allocated to SuDS, costs and water quality can be managed differently to satisfy more efficiently the holistically stakeholders' objectives. [ABSTRACT FROM AUTHOR]

Best management practices (BMPs) were used to reduce the NPS in various fields. The Korean Ministry of Environment has developed a total maximum daily load (TMDL) and adapted it to prevent water resources from pollutants in four major rivers. However, many water bodies in Korea are still polluted. It is anticipated that the NPS pollution flows into the water bodies without treatment. Nowadays, BMPs are enforced to reduce the NPS pollutant in Korean TMDL.This paper analyzes the characteristics of the reduced pollution loads by two different BMPs. We also calculate the reduced pollutant mass and the reduced pollutant loading rate to help make a plan for the pollution reduction in the Korean TMDL.The characteristics of the pollutant reduction in the BMPs were revealed through analysis of the EMC, first flush phenomenon and reduced pollution loads. Integrated facilities which combined two facilities were more effective to reduce the pollutant than the single and it was better to remove the beginning of the runoff as a first flush effectively than treat all runoff in the facilities. [ABSTRACT FROM AUTHOR]

Effective watershed management often demands qualitative and quantitative predictions of the effect of future management activities as arguments for policy makers and administration. The BASINS geographic information system was developed to compute total maximum daily loads, which are helpful to establish hydrological process and water quality modeling system. In this paper the BASINS toolkit HSPF model is applied in 20,271km2 large watershed of the Han River Basin is used for applicability of HSPF and BMPs scenarios. For proper evaluation of watershed and stream water quality, comprehensive estimation methods are necessary to assess large amounts of point source and nonpoint-source (NPS) pollution based on the total watershed area. In this study, The Hydrological Simulation Program-FORTRAN (HSPF) was estimated to simulate watershed pollutant loads containing dam operation and applied BMPs scenarios for control NPS pollution. The 8-day monitoring data (about three years) were used in the calibration and verification processes. Model performance was in the range of "very good" and "good" based on percent difference. The water-quality simulation results were encouraging for this large sizable watershed with dam operation practice and mixed land uses; HSPF proved adequate, and its application is recommended to simulate watershed processes and BMPs evaluation. [ABSTRACT FROM AUTHOR]

Main pollution sources in multipurpose dam watersheds in Korea are highland fields, stream banks, livestock farms, roads, and construction sites. Specifically, highland fields are the major nonpoint pollution sources. Excessive organic chemicals such as fertilizer and pesticide can be exuded from the land, and the area is likely to be eroded by heavy rain. Fallow, conservative cultivation, and covering can be alternatives for soil protection and reinforcement. In addition to these, construction of detour waterways and improvement of irrigation method can minimize the impact of runoff. In the case of slope in 15% degree or more, prohibiting cultivation and restoring the surface is preferred to improving cultivation method in order to control nonpoint pollution sources efficiently. [ABSTRACT FROM AUTHOR]

The paper presents a complex environmental engineering tool, which is appropriate to support decision making in watershed management. The PhosFate tool allows planning best management practices (BMPs) in catchments and simulating their possible impacts on immissions. The method has two parts: (a) a simple phosphorus (P) fate model to calculate diffuse P emissions and their surface transport, and (b) an interactive tool to design BMPs in small catchments. The fate model calculates diffuse P emissions via surface pathways. It is a conceptual, distributed parameter and long-term (annual) average model. The model also follows the fate of emitted P from each cell to the catchment outlets and calculates the field and in-stream retention. The fate model performed well in the Zala River catchment as a case study. Finally, an interactive design tool was developed to plan BMPs in the catchments and simulate their possible impacts on diffuse P fluxes. Different management scenarios were worked out and their effects evaluated and compared to each other. The results show that the approach is suitable to test BMP scenarios at small catchment scale. [ABSTRACT FROM AUTHOR]

Although street sweeping is commonly regarded as a cost-effective stormwater best management practice, there is little quantitative evidence that street sweeping directly improves runoff water quality. In this paper, several previous street sweeping studies were re-evaluated using statistical power analysis. Two-group, independent-sample one-sided t-test power analyses were performed using log-transformed event mean concentrations (EMCs) of total suspended solids, suspended sediment concentration or chemical oxygen demand. The effect size between the two groups was estimated using the sweepers' pick-up efficiency, which showed that the failure to detect the difference between mean EMCs of the two sample groups (i.e., unswept and swept groups) is likely due to limited sample numbers. Too few samples, which also resulted in a high coefficient of variation, were analysed to detect the likely difference between swept and unswept observations. In addition, the temporal gap between street sweeping and subsequent storm events was not controlled to improve statistical power. [ABSTRACT FROM AUTHOR]

Modelling tools have been widely used to investigate best management practices. But in contrast to the plethora of modelling studies, the practical implementation of outcomes is comparatively small. There is an urgent need to implement results and to show the practical validation of the concept developed, especially against the context of water stress mitigation. The participative development of modelling studies as a joint effort of stakeholders and modellers is seen as a key to achieve a wider identification, acceptance, trust and applicability of results. Participatory planning in the water sector is also increasingly requested in water management, where tasks have been for clarified decades through different institutional arrangements and national laws. Stakeholder involvement in water resources management have been limited to what was long time seen as participation, merely information on action to be taken. In the last decade the need for participation has been reflected in different ways. In Europe, the implementation of the Water Framework Directive (WFD) under Art. 14, requires all the European countries to involve stakeholders in decision making processes on water resource management. The aim of this paper is to present and discuss the research framework and possible results of investigating dam modelling through participatory systems modelling. We introduce a structured approach to use participatory modelling (PM) for stimulating the integration of modelling and decision making, also as a way of implementation of some articles of the WFD. The results and the framing of this paper are part of the AQUASTRESS Project. The conceptual modelling has been developed by a multidisciplinary research team, local stakeholders and local experts. Some results are discussed and recommendations made. [ABSTRACT FROM AUTHOR]

The overwhelming importance of diffuse sources as a determinant of receiving water quality has been recognised for over 30 years. Significant research and development on techniques for reducing inputs in the riparian zone has resulted in numerous guideline documents being produced. Yet despite this research effort, and the apparently successful transfer of key results to water resource managers, the public perception in New Zealand is that the quality of receiving waters continues to decline. In this paper we examine the veracity of that perception through examination of state-of-the-environment reporting, discussions with water resource managers, and published literature. Using a case study of Lake Taupo, New Zealand as an example, we discuss the difficulties faced by water resource managers in arresting declines in water quality. We compare the reduction in potential nutrient exports possible between 'non-invasive' mitigation techniques such as riparian buffer strips, constructed and natural wetlands and source control measures such as the use of nitrification inhibitors and wintering pads. Finally, we look at options available should voluntary measures or best management practices fail to deliver the nutrient reductions that are necessary to maintain lake water quality. [ABSTRACT FROM AUTHOR]

Best Management Practices (BMPs) are increasingly used to restore river water quality but design guidance is limited. An alternative approach to remediating diffuse pollution loads is to identify the most polluting high flows from pollutographs and hydrographs and spill these flows into riparian treatment wetlands for treatment before drainage back into the watercourse. The approach is demonstrated for two contrasting catchments in Scotland impacted by diffuse pollution. The Caw Burn receives industrial estate drainage with high suspended solids, hydrocarbons, BOD and ammoniacal-nitrogen concentrations. Applying the proposed design criteria demonstrated that the existing retrofit BMP system at the site is undersized (4950m²) compared to the required wetland area (11,800m²), but accommodating the additional area is likely to be expensive. The second case-study is Brighouse Bay where bathing waters are impacted by faecal indicator organisms derived primarily from livestock runoff. In this catchment the riparian wetland area required to retain runoff so that E. coli bacteria would die-off to concentrations below bathing water standards was estimated to be 3-6 ha (0.5-1% of catchment area). Further refinement and testing of the design approach is required, including consideration of other factors such as vegetation type, ownership and maintenance, to develop a more holistic approach to river restoration. [ABSTRACT FROM AUTHOR]

Water bodies are highly stressed by overdrafts of water for many purposes upstream and in the cities, and effluent domination and excessive point and diffuse pollution downstream. Pollution is also caused by the urban landscape which prefers impervious rather than porous surfaces; fast-conveyance infrastructure rather than "softer" approaches like ponds and vegetation; and stream channelization instead of natural stream courses, buffers and floodplains, and development in the floodplains. In future, the comprehensive and complex problems of urban pollution must be solved within the framework of the total hydrological cycle concept. This provides a new impetus to diffuse pollution management in urban areas. The best management practices that have been developed in the past could become key components of the new urban total hydrological cycle paradigm for solving the water shortage and pollution problems in an integrated manner, and making the urban systems hydrologically and ecologically sustainable. The paradigm will include landscape changes (less imperviousness, more green space used as buffers and groundwater recharge) as well application of the best management practices that provide water conservation, storage and reuse. [ABSTRACT FROM AUTHOR]

Seventy-nine and 103 sites within Glasgow and Edinburgh, respectively, were identified to assess if best management practice (BMP) can be integrated into future development, regeneration and retrofitting plans. A practical BMP Decision Support Model based on a matrix and weighting system, incorporating the Prevalence Rating Approach for BMP Techniques (PRABT), has been developed. The findings indicate that ponds (or lined ponds) and permeable pavements are the most likely individual BMP techniques, and ponds combined with swales (or shallow swales) are the most recommended dual BMP combination. A separate case-based reasoning model compared to the ‘linear’ BMP Decision Support Model has also been developed. The output was similar to the ‘linear’ model. [ABSTRACT FROM AUTHOR]

In order to estimate the detention effect (storage and peak flow attenuation) of a sedum green-roof, a comparison between the response of an impervious roof (runoff coefficient C = 1) and a green-roof has been carried out. Precipitation and runoff data from several controlled experiments (with wet initial conditions, i.e. approximately at field capacity) on a sedum green-roof were used for the analysis. For events with variable rain intensity, the green-roof's attenuation effect was as high as 65% for design storms. In contrast, events with constant intensity had increases in peak flows of up to 5%. The lowest detention volumes were observed for the experiments with constant rain intensity, for which a maximum of 29% of the rain volume was detained, whereas for rain events with variable intensity the detention volume was up to 52%. Simulations (using PondPack), based on a real case study, showed that green-roofs can be implemented in combination with other structural best management practices (BMPs) to obtain a desired detention. They can be used to reduce the size of other structural BMPs, and can occupy unused space that is readily available. [ABSTRACT FROM AUTHOR]

The efficacy of using constructed wetlands (CWs) to sequester organic carbon and nutrients from irrigation tailwaters was studied in the San Joaquin Valley, California. Two CWs were monitored during the 2004 irrigation season, a new CW (W-1) and 10-year-old CW (W-2). Input/output waters from CW were collected weekly and analyzed for a variety of water quality contaminants. Organic carbon, nutrient and sediment retention efficiencies were evaluated from input/output concentrations. Characteristics of sediment were examined spatially at W-2. Results indicate that W-2 was more efficient at contaminant removal. Average particulate organic carbon retention, was 70 ± 13% (mean ± standard deviation) in W-2 and 48 ± 32% in W-1. Chlorophyll-a, a measure of algal biomass, was higher at W-1, especially in input waters. Initially, output concentration of chlorophyll-a increased 15-fold in W-2, however over time, as emergent vegetation established, chlorophyll-a decreased to 35% of input levels. Average total N removal efficiency was 45 ± 18% for W-2 compared to 22 ± 32% in W-1. Total P removal efficiency was 72 ± 14% at W-2 compared to 18 ± 26% at W-1. CWs were most effective at removing total suspended solids, 84 % 15% and 97 ± 2% for W-1 and W-2, respectively. Results demonstrate that CWs are effective at capturing POC, sediment and nutrients from irrigation tailwaters. [ABSTRACT FROM AUTHOR]

Commissioned by Germany's Working Group of the Federal States on Water Problems (LAWA) the authors developed a procedure to define natural groundwater conditions from groundwater monitoring data. The distribution pattern of a specific groundwater parameter observed by a number of groundwater monitoring stations within a petrographically comparable groundwater typology is reproduced by two statistical distribution functions, representing the "natural" and "influenced" component. The range of natural groundwater concentrations is characterized by confidence intervals of the distribution function of the natural component. The applicability of the approach was established for 17 hydrochemical different groundwater typologies occurring throughout Germany. Based on groundwater monitoring data from ca. 26,000 groundwater-monitoring stations, 40 different hydrochemical parameters were evaluated for each groundwater typology. For all investigated parameters the range of natural groundwater concentrations has been identified. According to the requirements of the EC Water Framework Directive (article 17) (WFD) this study is a basis for the German position to propose criteria for assessing a reference state for a "good groundwater chemical status". [ABSTRACT FROM AUTHOR]

In the Netherlands the leaching of heavy metals from metal building and constructing materials results in serious contamination problems in the water system. The most common sources of these heavy metals in construction materials are copper waterworks and roofs, zinc roofs, gutters and rain pipes, zinced steel, stainless steel, and lead sealing material. In urban waters the surface water and sediment standards are often exceeded. Although building and construction materials are certainly not the only source of heavy metals, they are an important part of the problem. This article focuses on six instruments that are in use in the Netherlands to try to reduce impact on the surface waters. In addition to this, national as well as international, a reconsideration of the risks and surface water standards for several heavy metals is considered. A balanced use of instruments can be considered as the application of a best practice. [ABSTRACT FROM AUTHOR]

Urban sources account for significant quantities of important diffuse pollutants, and urban watercourses are typically badly polluted. As well as toxic metals, hydrocarbons including PAHs, and suspended matter, priority urban pollutants include faecal pathogens and nutrients. Can urban watercourses be restored by sufficient reductions in pollution loads? Case studies in the UK and Sweden provide insights and some grounds for optimism. A major trans-Atlantic review of the performance of best management practices (BMPs) is informing BMP planning. New approaches such as the maximisation of self-purification capacity in the receiving waters may also need to be developed, alongside BMPs at source. Other initiatives in Europe, USA and China, including collaborative projects, are trying to address the intractable issues such as persistent pollutants from transport and urban infrastructure. The challenge is daunting, but there are clear ways forward and future research needs are evident. [ABSTRACT FROM AUTHOR]

The objective of the present work is to compare two methodologies based on multicriteria analysis for the evaluation of stormwater systems. The first methodology was developed in Brazil and is based on performance-cost analysis, the second one is ELECTRE Ill. Both methodologies were applied to a case study. Sensitivity and robustness analyses were then carried out. These analyses demonstrate that both methodologies have equivalent results, and present low sensitivity and high robustness. These results prove that the Brazilian methodology is consistent and can be used safely in order to select a good solution or a small set of good solutions that could be compared with more detailed methods afterwards. [ABSTRACT FROM AUTHOR]

Continuous simulation is performed using the US Environmental Protection Agency (USEPA) Storm Water Management Model (SWMM) to evaluate regional differences around the United States in hydrologic and water quality performance of wet-weather controls. Controls are characterised as being limited by peak inflow rate (i.e. any device with little or no storage, such as screens, filters and some proprietary devices) or by storage capacity (e.g. ponds, tanks). For flow-limited devices, results are presented in the form of percentage of annual runoff volume captured (passing through the device) for a given inflow capacity. For storage-limited devices, results are presented in two forms: percentage of annual runoff volume captured as a function of unit basin size and drawdown (drain) time, and as a percentage of total suspended solids captured, for the same two variables. Regional differences are apparent, driven mainly by variations in rainfall patterns around the country. [ABSTRACT FROM AUTHOR]

Highway runoff can cause a number of water quantity and quality problems. Stormwater management systems for highways have been developed based on a fast drainage for large storm situations. Non-point source pollution from highway runoff is a growing water quality concern. Stormwater quality control needs to be integrated into highway drainage design and operation to reduce the stormwater impacts on the receiving water. A continuous simulation/optimisation model for analysing integrated highway best management practices (BMPs) is presented. This model can evaluate the life cycle performance of infiltration and/or storage oriented highway BMPs. It can be directly integrated with spreadsheet optimisation tools to find the least cost options for implementing BMPs throughout a specified life cycle. [ABSTRACT FROM AUTHOR]

Experimental results are described to evaluate the diffuse pollution profile according to land use in the catchments and street sweeping as a best management practice (BMP). We studied the variation of pollutant concentrations in outfalls discharging runoff from residential, commercial and high-traffic areas and in street sweeping. Pollution profiles varied with the land use in the catchments and seasons along with other factors such as rainfall intensity, construction works and street maintenance. Microbial indicator organisms were relatively high in all three outfalls. - Heavy metal concentrations were low with lead (Pb) as the predominant heavy metal. The organic and solid contents were low but non-degradable and persistent. Relatively high quantities of pollutants were found in street sweeps in all catchments suggesting street sweeping as an effective measure to control diffuse pollution. Regular and frequent sweeping is important as a BMP. [ABSTRACT FROM AUTHOR]

The focus of this paper is on variability concerns in wastewater treatment and approaches to control unacceptable fluctuations in effluent quality. Areas considered include: factors contributing to variability in both waste loads and process technology performance; variability assessment; control of variability employing the process best management practice (BMP); design/operation of biological waste treatment technologies for variability reduction; and modelling to enhance process control. [ABSTRACT FROM AUTHOR]

Identification of the pollution sources and understanding the processes related to runoff generation and pollution transportation is effective for the water quality management and selection of the Best Management Practices. The ANNualized AGricultural Non-Point Source (AnnAGNPS) model was applied to a watershed in Southern Ontario to evaluate the hydrology and sediment component from the non-point sources. The model was run for two years (1998 to 1999); one year's data was used to calibrate and the second year's data was used for validation purposes. The model has under predicted runoff amount and over predicted the sediment yield. However, the simulated runoff and sediment yield compared fairly well with the observed data indicating that the model had an acceptable performance in simulation of runoff and sediment. The study is still in progress to assess its performance for estimation of TMDL and improvements needed for the model to use under Ontario conditions. [ABSTRACT FROM AUTHOR]

Litter characterization is an integrated part of the Caltrans First Flush Characterization Study. These data will provide a basis to develop potential treatment technologies and best management practices to control pollutants in runoff from freeways. During monitoring periods in Southern California areas, the first flush phenomenon was evaluated and the impacts of various parameters such as rain intensity, drainage area, peak flow rate, and antecedent dry period on litter volume and loading rates were evaluated. First flush phenomenon was generally observed for litter concentrations, but was not apparent with litter mass loading rates. Total captured gross pollutants, defined as larger than 0.5 cm, was 90% vegetation with only 10% being litter. The normalized cumulative litter loadings were determined from 1.25 to 13.39 kg/ha for dry litter weight and 0.40 to 8.99 kg/ha for dry biodegradable litter weight. The portions of biodegradable litter to non-biodegradable litter were roughly the same across the entire event. Event mean concentrations were ranged 0.0021 to 0.259 g/L for wet gross pollutants, 0.0001 to 0.027 g/L for wet litters and 0.00007 to 0.018 g/L for dry litters. The mass emission rates should be useful to estimate total litter production for developing total maximum daily loads. [ABSTRACT FROM AUTHOR]

A water quality model applicable to rice paddies was developed using field data from 1999-2002. Use of the Dirac delta function efficiently explained the nutrient-concentration characteristics of ponded water. The model results agreed reasonably well with the observed data. The ponded-water quality was influenced primarily by fertilization; nutrient concentration was especially high during early cultivation periods. Reducing surface drainage during the fertilization period may substantially reduce nonpoint source loading from paddies. Increased weir heights and shallow irrigation methods were evaluated by the model as practical methods for reducing nutrient loading from paddies. These methods were effective in reducing surface drainage and are suggested as "best management practices" (BMPs) if applied based on site- specific paddy conditions. [ABSTRACT FROM AUTHOR]

Characteristics of solids recovered from stormwater best management practice (BMP) facilities, including stormwater ponds, constructed wetlands, an infiltration basin, a biofilter, a stormwater treatment clarifier, and three-chamber oil and grit separators were described with respect to their metal chemistry. The reported trace metal concentrations in BMP sediments were assessed against the Ontario Sediment Quality Guidelines. Between 80 to 100% of all samples were marginally-to-intermediately polluted by Cd, Cr, Cu, Fe, Pb, Mn, Ni and Zn. Severe pollution of sediments was noted for Cr (122 µg/g), Cu (151 and 196 µg/g), Mn (1,259 and 1,433 µg/g), and Zn (1,116 µg/g), at several facilities studied, and even higher levels of metals were reported in the literature for certain oil and grit separators. With respect to individual BMPs, the severe pollution was found in sediments from oil and grit separators (for Cd, Cr, Cu, Pb and Zn), the stormwater clarifier sludge (Cu, Mn and Zn), a biofilter (Cu and Mn), an industrial area stormwater pond (Cu only), and a commercial/residential pond (Cr only). Finally, the chemical pollution of pond sediment triggered toxicity testing at some of the facilities studied, and sediment toxicity was confirmed at several sites. [ABSTRACT FROM AUTHOR]

Water quality in China shows an overall trend of deterioration in recent years. Nonpoint source pollution from agricultural and rural regions is the leading source of water pollution. The agricultural nonpoint source pollutants are mainly from fertilization of cropland, excessive livestock and poultry breeding and undefined disposal of daily living wastes in rural areas. Agricultural nonpoint sources contribute the main source of pollution to most watersheds in China, but they are ignored in management strategy and policy. Due to the lack of full understanding of water pollution control and management and the lack of perfect water quality standard systems and practical legislative regulations, agricultural nonpoint source pollution will become one of the biggest challenges to the sustainable development of rural areas and to society as a whole. The system for agricultural nonpoint source pollution control in China should include an appropriate legislation and policy framework, financing mechanisms, monitoring system, and technical guidelines and standards. The management of agricultural nonpoint source pollution requires multidisciplinary approaches that will involve a range of government departments, institutions and the public. [ABSTRACT FROM AUTHOR]

Applicability of a widely accepted watershed-based water quality assessment tool (BASINS) and its associated watershed model (WinHSPF) was evaluated on the Seamangeum watershed in Korea. The study site is the largest polder project area in Korea and its environmental quality has been debated for the last jive years. BASINS was found to be a convenient and powerful tool for assessment of watershed characteristics, and provided various tools to delineate the watershed into land segments and river reaches, reclassify land use, and parameterize for WinHSPF simulation. Calibration results were satisfactory showing model efficiency over 0.80 for stream flow, temperature, and dissolved oxygen simulation, and model output for water quality constituents also reasonably matched the observed data. It was demonstrated that calibration with dry-day data for a relatively long period might be adequate to simulate hydrologic characteristics and water quality of the watershed with WInHSPF, and using parameters generated with BASINS for nonpoint source pollution simulation is suggested when enough wet-day monitoring data are not available. The unit-area load of biochemical oxygen demand, total nitrogen, and total phosphorus was 27.8, 48.2, and 4.3kg/ha/yr, respectively. These values are within the expected range but on the high side of the reported values, which implies that effective control measures are required to protect water quality of the downstream reservoir. Overall, BASINS/WinHSPF was applicable and found to be a powerful tool in pollutant loading estimation from the watershed, and its use in Korea is recommended. [ABSTRACT FROM AUTHOR]

This paper describes a modelling approach for evaluating the efficiency of different non-structural best management practices for stormwater management. A scenario with a set of source reduction practices was simulated using the substance flow model SEWSYS for an urban catchment in the city of Göteborg, Sweden. The scenario is based on a hypothetical control program that includes prevention, education and regulations. The simulation shows relatively high reductions of copper and PAH, 77% and 50%, respectively. The reduction in copper is mainly due to less copper roof corrosion and brake wear, while reduced road wear has the greatest effect for PAH. An important result from this study is that the nonstructural BMPs applied did not give a sufficient reduction in pollution to meet the desirable environmental quality criteria. To meet these criteria, additional BMPs must be implemented, preferably a combination of both non-structural and structural measures. [ABSTRACT FROM AUTHOR]

Water management is surrounded by uncertainties. Water management thus has to answer the question: given the uncertainties, what is the best management strategy? This paper describes the application of the perspectives method on water management in the Rhine and Meuse basins. In the perspectives method, a structured framework to analyse water management strategies under uncertainty is provided. Various strategies are clustered in perspectives according to their underlying assumptions. This framework allows for an analysis of current water management strategies, but also allows for evaluation of the robustness of proposed future water strategies. It becomes clear that no water management strategy is superior to the others, but that inherent choices on risk acceptance and costs make a real political dilemma which will not be solved by further optimisation. [ABSTRACT FROM AUTHOR]

Phosphorus loads from agricultural non-point source pollution (NPSP) significantly degrade reservoir water quality, making adequate control of agricultural NPSP necessary for improving the water quality. Controlling NPSP is generally accomplished using various Best Management Practices (BMPs). The present study applies the Agricultural Non-Point Source Pollution (AGNPS) model to simulate NPSP loading and BMP efficiencies and establishes an enhanced multiobjective mixed-integer programming model for NPSP control strategy analyses based on these results. Cost, phosphorus load, sediment load and equity are the four major objectives considered. A case study for the Posan reservoir is presented. Four commonly proposed and applicable BMPs are chosen. Non-inferior solutions obtained using the constraint method and trade-off relationships among different control objectives are described and discussed. Compared with a previously proposed fertilizer control model, results show that the model established herein is more costeffective and achieves better phosphorus and sediment loading reduction and equity goals. Furthermore, the current model is expected to facilitate decision-making analysis for development of an appropriate cost-sharing program to encourage adoption of appropriate BMPs by farmers. [ABSTRACT FROM AUTHOR]

The Cotton and Grains Adoption Program of the Queensland Rural Water Use Efficiency Initiative is targeting five major irrigation regions in the state with the objective to develop better irrigation water use efficiency (WUE) through the adoption of best management practices in irrigation. The major beneficiaries of the program will be industries, irrigators and local communities. The benefits will flow via two avenues: increased production and profit resulting from improved WUE and improved environmental health as a consequence of greatly reduced runoff of irrigation tailwater into rivers and streams. This in turn will reduce the risk of nutrient and pesticide contamination of waterways. As a side effect, the work is likely to contribute to an improved public image of the cotton and grain industries. In each of the five regions, WUE officers have established grower groups to assist in providing local input into the specific objectives of extension and demonstration activities. The groups also assist in developing growers' perceptions of ownership of the work. Activities are based around four on-farm demonstration sites in each region where irrigation management techniques and hardware are showcased. A key theme of the program is monitoring water use. This is applied both to on-farm storage and distribution as well as to application methods and in-field management. This paper describes the project, its activities and successes. [ABSTRACT FROM AUTHOR]

Discusses the application of Best Management Practices (BMP) for stormwater-runoff with alternative methods in a large urban catchment in Berlin, Germany. Overview of the area of investigation; Decentral stormwater-maangement-systems; Use of geographic information systems to investigate the possibilities of implementing decentral measures in larger areas; Conversion of retention tanks into soil filter tanks.