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The stormwater runoff carries different pollutants that can reduce the quality of receiving waters due to diffuse pollutant loads. This research was aimed at evaluating the concentration of pollutants in stormwater and the application ofSWMM(Storm Water Management Model) to an urban catchment in Lake Paranoá watershed to carry out the simulation of flow discharge with the hydraulic model, and subsequently to estimate the loads conveyed to the lake in ordinary events of precipitation. This study was carried out based on rainfall and runoff monitoring during events. It was confirmed that this model's results fit well in simulation of this type of watershed, leading to high value of the Nash-- Sutcliffe coefficient after calibration but, as expected, precipitation distribution is a very important factor for calibration. Concerning water quality, it was observed that the event mean concentration values of suspended solids and chemical oxygen demand were high, indicating that the diffuse pollution is an important source of pollution of the receiving waters. The monitoring and modelling of stormwater are essential to identify diffuse pollution discharge, in searching for a sustainable solution. [ABSTRACT FROM AUTHOR]

The management of stormwater pollution has placed particular emphasis on the first flush phenomenon. However, definition and current methods of analyses of the phenomena contain serious limitations, the most important being their inability to capture a possible impact of the event size (total event volume) on the first flush. This paper presents the development of a novel approach in defining and assessing the first flush that should overcome these problems. The phenomenon is present in a catchment if the decrease in pollution concentration with the absolute cumulative volume of runoff from the catchment is statistically significant. Using data from seven diverse catchments around Melbourne, Australia, changes in pollutant concentrations for Total Suspended Solids (TSS) and Total Nitrogen (TN) were calculated over the absolute cumulative runoff and aggregated from a collection of different storm events. Due to the discrete nature of the water quality data, each concentration was calculated as a flow-weighted average at 2mm runoff volume increments. The aggregated concentrations recorded in each increment (termed as a 'slice' of runoff) were statistically compared to each other across the absolute cumulative runoff volume. A first flush is then defined as the volume at which concentrations reach the 'background concentration' (i.e. the statistically significant minimum). Initial results clearly highlight first flush and background concentrations in all but one catchment supporting the validity of this new approach. Future work will need to address factors, which will help assess the first flush's magnitude and volume. Sensitivity testing and correlation with catchment characteristics should also be undertaken. [ABSTRACT FROM AUTHOR]

With the implementation of Pollutant Discharge and Transfer Register (PRTR) in fiscal 2003, information on the quantity of chemical substances discharged annually from each business is released in Japan. Such information is expected to lead to heightened public concern about the presence of chemical substances in environment. This paper showed the effects of using PRTR data for managing chemical risk in a water environment communicating among stakeholders based on the results of the case study held in Japan. First, it was possible to identify the discharge sources using PRTR and related data for the chemicals such as Zn and NPs which were shown that they had relatively high risks based on the survey in a model area. Second, it was suggested that the chemical risk communication among the stakeholders including people using PRTR and related data would be a good way to encourage environmental activities of businesses, and to build a good relationship among stakeholders including people who have anxiety about chemical risk. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the use of total coliforms (TC) and faecal coliforms (FC) using a membrane filtration method for precise monitoring of faecal pollution in Korean surface water. The samples were collected in Korea from both main rivers and their tributaries. Presumptive TC · FC were enumerated. The ratios of presumptive FC to TC were not constant, but varied widely, and TC were difficult to enumerate because of overgrowth by background colonies. For FC this was not the case. Seven hundred and three purified strains of presumptive TC · FC and their background colonies were biotyped using API 20E. Among 272 presumptive TC, non-faecal related species, Aeromonas hydrophila dominated (34.6%) and E. coli accounted for only 5.1%. In contrast, E. coli made up 89% of the 909 presumptive FC. Furthermore, of 164 background colonies on Endo Agar LES, 54.9% was A. hydrophila, while background colonies on m-FC Agar were few (58 strains), and despite their atypical colony appearance, most of them were biotyped as enteric bacteria. These results reveal that the detection of FC rather than TC using m-FC Agar is more appropriate for faecal pollution monitoring in eutrophicated surface water located in a temperate region. [ABSTRACT FROM AUTHOR]

Field monitoring of the toxic organic compounds (PCBs, PAHs, organochlorine pesticides) in the top sediments of Pearl River Estuary and its up-streams were made. It was found that the highest concentrationsof these toxic organic compounds occurred in the sediment sampled atMacau inner harbor (ZB013), which is a sink of suspended fine particles transported from the upstream waterways. Because of the affinity of the hydrophobic organic compounds (PAHs, PCBs) for the solid phase, these fine particle depositions led to accumulation of these compounds in the sediment of Macau. The atmospheric dry deposition may be another source of the toxic organic pollution in the sediment. [ABSTRACT FROM AUTHOR]

This study discusses the estrogenicity and the extent of estrogenic effects, of sewage and treated sewage in public sewage treatment plants in Japan. The estrogenicity in this study was measured with a DNA recombinant yeast strain. Using this method, 43 chemicals that are suspected to have estrogen-like effects were measured and their estrogenicities were evaluated in terms of 17beta-estradiol equivalents by comparison with the estrogenicity of 17beta-estradiol. 17beta-estradiol equivalents of influent and effluent sampled from 20 sewage treatment plants (STPs) were measured with this method. Because the concentrations of endocrine disruptors (EDs) in the STPs were monitored by the Ministry of Construction (MOC), the estrogenic effects estimated from the chemical data were obtained as a theoretical estrogenicity in terms of 17beta-estradiol equivalent. The results suggest that STPs effectively reduce the estrogenicity and the theoretical estrogenicityduring treatment, and that there were some differences between the estrogenicity assayed by the yeast and the theoretical estrogenicity in many STPs, particularly in influent sewage. Therefore, it is implied that unknown estrogen-like substances or antagonists might exist ininfluent sewage and treated sewage in STPs. [ABSTRACT FROM AUTHOR]

A combined method of passive and active sampling of volatile organiccompounds (VOCs) in a sewer system is presented. Passive sampling devices are used to locate and identify volatile organic compounds in the sewer atmosphere. Passive sampling is a time-integrating method and its results are only qualitative. To get quantitative information active sampling of wastewater is necessary. Concentrations of VOCs obtained from active sampling are used as input values for a simplified form of the two-film-model. This model allows to compute concentrations of VOCs at different points in a sewer stretch. We employed this method to describe the behaviour of volatile chlorinated hydrocarbons within a sewer stretch in Bayreuth, Germany. [ABSTRACT FROM AUTHOR]

Cleaning agents and disinfectants from housekeeping, hospitals and canteen kitchens are important sources of adsorbable halogenated organic compounds (AOX) in municipal waste water. They often contain inorganic compounds which are able to release activated chlorine. Togetherwith organic waste water compounds the activated chlorine can generate halogenated organic compounds. Within the scope of this research project the generation of AOX through these active agents is compared.The effects of concentration, pH, time, temperature, presence of other oxidizing or reducing agents and synergetic effects are investigated and discussed. According to the results the potential of these active agents forming AOX is obvious. The AOX concentration of a municipal waste water increased by the factor of 13 after adding an hypochlorite containing disinfectant in common concentration. Most AOX can beformed within 30 minutes. In sewage with high amount of solid compounds the AOX generation can take a long time (several days). The amount of AOX generated strongly depends on the nature and concentration of dissolved and solid organic compounds, the concentration of active substances, temperature, pH and the reaction time. [ABSTRACT FROM AUTHOR]

An experimental urban catchment has been created in the centre of Paris, in order to obtain a description of the pollution of urban wet weather flows at different levels of the combined sewer system, and toestimate the contribution of runoff, waste water and sewer sedimentsto this pollution. Twenty-two rainfall events were studied from May to October 1996. Dry weather flow was monitored for one week. Roof, street and yard runoff, total flow at the catchment outlet and waste water were analysed for SS, VSS, COD and BODs, on both total and dissolved fraction. Results show an evolution in the characteristics of wet weather flow from up to downstream: concentrations increase from the catchment entry to the outlet, as well as the proportion of particle-bound pollutants and the part of organic matter. A first evaluationof the different sources of pollution establishes that a major part of wet weather flow pollution originates from inside the combined sewer, probably through erosion of sewer sediments. [ABSTRACT FROM AUTHOR]

The research project 'Real Time Control of a Combined Sewer System by Radar estimates of Precipitation' seeks to improve the water quality of a stream by reducing quantitative and qualitative discharges of combined sewage overflow (CSO). The complex monitoring and simulationsystem that has been set up for control purposes is described. Two advanced real time control (ARTC) strategies have been developed. First a pollution based real time control (PBRTC) strategy, and second a water quality based real time control (WQBRTC) strategy. The PBRTC strategy is already implemented, the WQBRTC strategy will be implemented during the course of the project. For the PBRTC an off-line analysis is presented to show the effectiveness of the strategy. [ABSTRACT FROM AUTHOR]