This report describes the effects of combined-sewer overflows (CSO's) and urban runoff on the water quality of Fall Creek during summer 1987 by comparing the water quality of base flow with that of storm runoff and by comparing water quality in the urbanized area with that in the less urbanized area upstream from the CSO's. Data were collected at three streamflow-gaging stations located upstream from, downstream from, and in the middle of 27 CSO's 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. Concentrations of dissolved oxygen measured at the station in the middle of the CSO's were less than the Indiana minimum ambient water-quality standard of 4.0 mg/L during all storms. Concentra- tions of ammonia, oxygen demand, copper, lead, zinc, and fecal coliform bacteria at the stations down- stream from the CSO's were much larger during runoff than during base flow. Increased concentrations of oxygen demand in storm runoff probably were caused by combined-sewer overflows, urban runoff, and the resuspension of organic material deposited on the streambed. Some of the increased concentrations of lead, zinc, and probably copper can be attributed to the discharge and resuspension of material back- washed from filters at the water-treatment plant.
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USGS Numbered Series
Effects of combined-sewer overflows and urban runoff on the water quality of Fall Creek, Indianapolis, Indiana
Water-Resources Investigations Report
U.S. Geological Survey ;
Earth Science Information Center, Open-File Reports Section [distributor],