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USEPA CSO CAPSTONE REPORT: RECEIVING WATER IMPACTS
Citation:
Minamyer*, K S. USEPA CSO CAPSTONE REPORT: RECEIVING WATER IMPACTS. Presented at Int Water Association's 5th Int Conf, Diffuse/Nonpoint Pollution and Watershed Mgmt, Milwaukee, WI, 6/10-15/2001.
Description:
Urban storm-generated combined sewer overflows (CSOs) significantly contribute to the degradation of the nation's water quality. Although not one of the largest pollution sources by volume, their impacts on receiving waters can be locally intense and visible due to shock effect and the long-term buildup of toxic contaminants in receiving water sediment. CSOs discharge pollutants contained in raw domestic sewage, industrial and commercial wastewater, and stormwater runoff directly to surface waters or to surface areas where pollutants can infiltrate the vadose zone and contaminante groundwater supplies. Because CSOs contain untreated domestic, commercial, and industrial wastes, as well as surface runoff, many different tyupes of contaminants can be present. Contaminants may include pathogens, oxygen-demanding pollutants, suspended solids, nutrients, toxics, and floatable matter. The urban stormwater component is often contaminated with organic matter, sediments, nutrients, heavy metals, pesticides, bacteria, toxic organics, dissolved and settleable solids and floatable materials. These contaminants, and the volume of flows, can cause a variety of adverse impacts on the physical and aesthetic characteristics of surface waters, impair the viability of aquatic habitats, and pose a potential threat to swimming waters and drinking water supplies. CSOs have contributed to shellfish harvesting restrictions, beach closures, and occasional fish kills. Representative case studies describing the impacts of CSOs on receiving waters will ge discussed.