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Land Application of Treated Sewage Sludge in the United States: Regulatory Considerations for Risk Reduction and Determining Treatment Process Equivalency
Citation:
MECKES, M. C. Land Application of Treated Sewage Sludge in the United States: Regulatory Considerations for Risk Reduction and Determining Treatment Process Equivalency. Presented at VII Simposio Interamericano de Biossolidos, Campinas (SP), BRAZIL, October 26 - 28, 2010.
Impact/Purpose:
To inform the public.
Description:
In the United States, municipal wastewater includes discharges from households, commercial businesses and various industries. Microorganisms associated with these wastes can be concentrated in the solids (sludge) which are removed during treatment operations. Beneficial reuse as a soil amendment/fertilizer is one of the options available for these solids, however, further treatment is required to control risks associated with pathogenic microorganisms. The U.S. Environmental Protection Agency (EPA) published regulations (U.S. EPA, 2003) to minimize the risk associated with land application of municipal sludge in 1993. These regulations describe alternative approaches to treatment and acceptable land application practices. EPA’s approach to reducing risks associated with pathogenic microorganisms in sludge is based upon reducing the densities of pathogenic and indicator microorganisms as well as vector attraction by treatment prior to land application. The U.S. regulations identify two separate classes of treatment designated “A” which has no detectable pathogenic microorganisms, and “B” which may contain pathogens. Municipal sludges which are designated Class A based upon treatment may be land applied without restriction, while Class B treated sludge (or biosolids) may only be land applied in accordance with land use restrictions designed to limit risk by limiting exposure.
