Biosolids

Doxins in Sewage Sludge

Decision Not to Regulate Dioxins in Sewage Sludge Disposed of at a Surface Disposal Site or Incinerated

EPA published in the Federal Register its final decision not to regulate dioxin in sewage sludge that is incinerated or placed in sludge landfills or containment ponds. EPA based its decision on an evaluation of the risk of exposure for people most likely to be exposed to dioxin from these sources. EPA concluded that existing regulations for incinerators, landfills or containment ponds adequately protect human health and the environment by limiting exposure to pollutants, including dioxins. Please note: This Federal Register Notice does not apply to Land Application.

Decision Not to Regulate Dioxins in Land-Applied Biosolids

In 2000 and 2001, the EPA and the Association of Metropolitan Sewerage Agencies (AMSA), now known as the National Association of Clean Water Agencies (NACWA), separately conducted surveys to determine current levels of dioxin-like compounds (i.e., polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans and dioxin-like coplanar PCBs) in biosolids (sewage sludge) that are land applied. These data were collected to assist U.S. EPA in developing an environmentally sound and technically correct dioxin decision for land-applied biosolids.

In October 2003, based on these surveys and other information, EPA published in the Federal Register its decision not to regulate dioxins in land-applied sewage sludge. After five years of study, including outside peer review, the Agency determined that land applied dioxins do not pose a significant risk to human health or the environment. The most highly exposed people, theoretically, are those people who apply sewage sludge as a fertilizer to their crops and animal feed and then consume their own crops and meat products over their entire lifetimes. EPA’s analysis shows that only 0.003 new cases of cancer could be expected each year or only 0.22 new cases of cancer over a span of 70 years. The risk to people in the general population of new cancer cases resulting from sewage sludge containing dioxin is even smaller due to lower exposures to dioxin in land-applied sewage sludge than the highly exposed farm family which EPA modeled.

The following documents summarize or helped support the development of final EPA actions on sewage sludge that is incinerated, placed in sludge landfills or containment ponds, or that is land applied regarding dioxin and dioxin-like compounds.

If you have trouble accessing any content in the following documents, please contact Rick Stevens by phone (202-566-1135) or email (stevens.rick@epa.gov).

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