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Statistical Support Document for the Development of Round 2 Biosolids Use or Disposal Regulations for Dioxins

Supporting regulation development for the use or disposal of biosolids containing dioxin and dioxin-like compounds, this document presents estimates describing the dry weight amount of biosolids used or disposed at various-sized treatment works across the country, distribution of toxic equivalents (TEQs) of dioxin and dioxin-like compounds in biosolids from publicly owned treatment works (POTWs) across the country, and the variability over time of dioxin and dioxin-like TEQs in biosolids from three POTWs. The estimated dry weight of biosolids used and disposed by POTWs were determined from data collected in EPA’s 1988 National Sewage Sludge Survey (NSSS). Dioxin and dioxin-like TEQs in biosolids as measured during the 2001 and 1988 NSSS support distributional assessments.

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