Information provided for reference purposes only

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    United States
    Environmental Protection
    Office of Water
    December 1999

    Proposed Rule Revising the Standards for Use and Disposal of Biosolids


    The U.S. Environmental Protection Agency (EPA) is publishing for public comment a proposed rule for dioxin and dioxin-like compounds (dioxins) in biosolids. Biosolids are treated sewage sludge, which is the byproduct of municipal wastewater treatment. Biosolids can be recycled and applied as a fertilizer, disposed of in surface disposal units, or incinerated.

    EPA is proposing to set a limit of 300 part per trillion (ppt) toxic equivalents (TEQ), as well as monitoring, record keeping and reporting requirements, for dioxins in biosolids that are land applied. The proposed rule does not contain additional limits for biosolids that are being placed in surface disposal units or incinerated.


    In compliance with section 405 of the Clean Water Act, EPA published the Standards for the Use or Disposal of Sewage Sludge, known as the Round One sewage sludge regulation, in February 1993. The Round One regulation set limits for metals, pathogens and total hydrocarbons for land application, surface disposal and incineration of sewage sludge.

    Section 405 of the Clean Water Act also requires a Round Two regulation for pollutants not previously regulated in Round One. As the result of a citizen's suit, EPA is required to propose Round Two regulations by December 15, 1999, and to take final actions by December 15, 2001. In November 1995, EPA notified the court that, based on risk assessment results, the Agency was considering further regulations only for dioxins.


    The proposed rule would require facilities which prepare biosolids for land application to test the biosolids for dioxins, and also to perform periodic monitoring to determine the level of dioxins.

    The proposal sets a limit of 300 parts per trillion toxic equivalents of dioxins, above which biosolids may not be applied to the land. All facilities would be required to test the level of dioxins present in their biosolids before the biosolids could be land applied except:

    (1) treatment plants treating less than one million gallons per day of wastewater, and (2) small businesses which prepare less than 290 dry metic tons of sewage sludge annually.

    The proposed rule would require facilities finding levels of dioxins between 30 and 300 ppt in their biosolids to monitor annually for dioxins, while facilities that find less than 30 ppt of dioxins would be required to monitor once every five years.

    Based on risk assessments, the Agency is not proposing additional numeric standards or management practice requirements for dioxins in biosolids that are to be placed in surface disposal units or incinerated.

    Additional Information

    For additional information concerning this proposed rule, contact:

    Arleen Plunkett
    Office of Science and Technology
    Health and Ecological Criteria Division (4304)
    401 M Street, S.W.
    Washington, D.C., 20460
    Telephone: 202- 260-3418

    You may view the Federal Register notice that describes this proposed rule on the Internet at: or request a copy from the National Service Center for Environmental Publications at 1-800-490-9198. The proposed rule includes complete information on how to review the docket for this proposal. Written comments on the proposed rule will be accepted by EPA for a period of 60 days after it is published. Address written comments to:

    Part 503 Sewage Sludge Use or Disposal Rule
    Docket W-99-18
    Comment Clerk
    Water Docket MC-4101
    Environmental Protection Agency
    401 M Street, S.W.
    Washington, DC 20460

Revised December 17, 1999