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LAND APPLICATION AND SLUDGE TREATMENT
Citation:
SMITH, J. E. LAND APPLICATION AND SLUDGE TREATMENT. Presented at USEPA/NERL Biosolids Exposure Measurement Workshop, Cincinnati, OH, March 16 - 17, 2006.
Description:
Fecal matter potentially containing pathogenic microorganisms and chemical contaminants enters community wastewater collection systems from hospitals, funeral homes, animal slaughtering operations, and dwellings. While these wastewaters are cleansed in the wastewater treatment plant, any pathogenic microorganisms or chemical contaminants that are present are largely concentrated in the sludge. Approximately 60% of the wastewater treatment plants and more than 40% of the nearly 7 million dry tons of sludge produced per year in the U.S.A. is beneficially used on the land. If that sludge is to be beneficially used on land and potentially come in contact with humans, it must meet federal and state disinfection, vector attraction reduction, and chemical (largely metal) concentration requirements for protecting the public health. Depending upon how the properly treated sludge (biosolids) is applied to the land; surface applied as a liquid or as a cake, incorporated following application, or injected it has potential to contaminate the land, water, and/or air; and as such affect the public health. A July 2002 NRC/NAS Report, "Biosolids Applied to Land" and USEPA's December 31, 2004 response recommended holding this exposure workshop and especially addressing the topic of bioaerosols and their movement off the land application site to residents in the nearby community. Work done by NRMRL in 2004 field study evaluated bioaerosol sampling with SKC impingers, an Anderson sampler, and button samplers for endotoxin measurement. This effort will be described early in the workshop to set the stage for later discussions.