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USEPA CAPSTONE REPORT: CONTROL AND TREATMENT
Citation:
Wojtenko**, I, C Y. Fan*, AND R Field*. USEPA CAPSTONE REPORT: CONTROL AND TREATMENT. Presented at 5th International Conference: Diffuse/Nonpoint Pollution and Watershed Management, Milwaukee, WI, June 01 - 15, 2001.
Impact/Purpose:
To inform the public.
Description:
Combined-sewer overflows (CSOs), sanitary-sewer overflows and stormwater (SW) are significant contributors of contamination to surface waters. During a rain event, the flow in a combined sewer system may exceed the capacity of the intercepting sewer leading to the wastewater treatment plant, thus releasing a mixture of stormwater and raw sanitary wastewater into the receiving water. This paper highlights the USEPA's NRMRL's research results for CSO control and treatment. Source control and collection system control are important aspects of CSO management. Source control includes flow as well as pollutant control, since dissolved pollutants and pollutants associated with particulate matter are also abated. Collection system control includes overflow and sediment reduction approaches such as improved sewer design, catchbasin improvement, and improved regulator performance. In addition, CSO management involves improved storage and treatment practices. The paper discussed inline and offline storage systems as well as in-receiving water storage systems. Three major types of treatment systems and their associated costs are also discussed: 1) physical (screening and sedimentation), where the benefits of high-rate vs. conventional processes are emphasized; 2) physical/chemical (filtration and high-rate sedimentation); and 3) biological (trickling filters, activated sludge, aerated lagoons, and rotating biological contactors).