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原文传递 QUANTITY AND QUALITY OF URBAN STORMWATER RUNOFF FROM SELECTED DRAINAGE BASINS, OMAHA, NEBRASKA, 1992-93

题名：	QUANTITY AND QUALITY OF URBAN STORMWATER RUNOFF FROM SELECTED DRAINAGE BASINS, OMAHA, NEBRASKA, 1992-93
作者：	Abraham H. Chen and Francis J. Jelinek
关键词：	storm；basins；quality；select；bras；inag；water；constituent；from；industrial
摘要：	The U.S. Geological Survey, in cooperation with the City of Omaha and the Papio-Missouri River Natural Resources District, Nebraska, conducted a study to describe stormwater-runoff quantity and quality from selected basins in Omaha. The study was done to meet technical data requirements for the City of Omaha to obtain a National Pollutant Discharge Elimination System Permit from the U.S. Environmental Protection Agency. Stormwater-runoff quantity and quality from five sites located in residential, commercial, and industrial land-use basins were monitored from May to November 1992 and April through August 1993. Sites 1 and 4 were representative of residential land use; sites 2 and 5 were representative of commercial land use; and site 3 was representative of industrial land use. Total rainfall, runoff volume, runoff-rainfall ratio, peak discharge, rainfall and runoff duration, and number of dry hours between storms were calculated and compiled. Mean rainfall during the study was slightly greater in the residential basins (0.60 inch) than in the commercial (0.4S inch) and industrial (0.46 inch) basins. However, mean runoff rainfall ratio for the industrial (0.32) and commercial (0.38) basins was more than twice the runoff-rainfall ratio of the residential basins (0.15). Grab samples and flow-weighted composite samples were collected at each of the five sites during six storms and were analyzed for 147 chemical, physical, and biological characteristics. Grab samples, collected within the first 30 minutes of each storm, represented the storm’s first-flush effects, and were analyzed for pH, water temperature, residual chlorine, volatile organic compounds, cyanide, total phenols, biological oxygen demand, fecal coliform and fecal streptococcus bacteria, and oil and grease. Flow weighted samples were composited during the first 3 hours of a storm and were analyzed for acid and base/neutral organic compounds, pesticides and polychlorinated biphenyls, trace elements, chemical oxygen demand, suspended solids, dissolved solids, nutrients, major ions, alkalinity, pH, specific conductance, and total organic carbon. The volatile organic compounds—chloroform, dichlorobromomethane, methyl chloride, and toluene—were detected in concentrations ranging from 0.4 to 7.0 micrograms per liter. Toluene was detected only in the residential basins. Eleven base/neutral compounds with concertrations ranging from 9 to 150 micrograms per liter were detected in a commercial basin (site 5) during a storm-runoff event May 22,1993. Eleven of 12 base/neutral compounds sampled for were detected at five sites. Concentrations of six of the compounds exceeded U.S. Environmental Protection Agency (USEPA) Maximum Contaminant Levels (MCLs) for drinking water. No pesticide or polychlorinated biphenyl concentrations exceeded MCLs. The trace elements—^total beryllium and total lead—exceeded MCLs for drinking water. Total lead also exceeded treatment action levels established by the USEPA for drinking water. Median concentrations of lead from the industrial basin were about 6 times greater than in the residential and commercial basins. Median concentrations of total copper, total nickel, and total zinc were about 3 times greater in samples collected from the industrial basin than from the residential and commercial basins. Stormwater-runoff constituent loads for 12 constituents were estimated using three methods. The ] 2 constituents were biochemical oxygen demand, chemical oxygen demand, suspended solids, dissolved solids, total nitrogen as nitrogen (N), total ammonia plus organic nitrogen as N, total phosphorus, dissolved phosphorus, total cadmium, total copper, total lead, and total zinc. The first method used was direct computation of observed data. The second method used was the USEPA simple method for calculating annual pollutant loads. The third method used was a statistical regression method, adjusting the regional models by using local monitoring data. The regression models estimated stormwater-runoff constituent loads.
报告类型：	科技报告