United States
Environmental Protection
Agency
Office of Water
4304T
EPA-822-F-02-005
June 2002
&EPA
Fact Sheet
Notice of Data Availability for Dioxins in Land-Applied Sewage Sludge -
Round 2 Part 503
Summary
This Notice of Data Availability (NODA) summarizes new data and a revised risk assessment
and invites public comments on this information. In December 1999, EPA proposed a numeric
standard for dioxins in sewage sludge which is applied to agricultural land. The Agency based
its proposed limit on the results of a risk assessment for dioxins in land-applied sewage sludge.
Since the proposal, EPA gathered new data and conducted a new risk assessment. We will
consider comments we receive during the 90-day public comment period in formulating the final
action.
The Round 1 Sewage Sludge Regulation
Part 503 is the comprehensive regulation for land application, surface disposal, and incineration
of sewage sludge under section 405 of the Clean Water Act. Section 405 calls for two "rounds"
of regulation: Round 1 addresses pollutants for which information was available at the time, and
Round 2 addresses additional pollutants. Because EPA did not meet the statutory deadline for
the Round 1 regulations, the Agency was sued and entered into a consent decree establishing a
schedule for both the Round 1 and 2 regulations.
In February 1993, EPA published the Standards for the Use or Disposal of Sewage Sludge.
Known as the Round 1 sewage sludge regulation, these standards contain the requirements for
sewage sludge that is applied to the land, placed in a surface disposal unit, or fired in a sewage
sludge incinerator. The Round 1 rule has been amended several times since then.
Proposed Round 2 Rule
In December 1999, EPA proposed to amend management standards by adding a numeric
concentration limit for dioxins in land-applied sewage sludge. Based on our initial risk
assessment, the proposed limit would prohibit land application of sewage sludge that contains
more than 300 parts per trillion toxic equivalents of dioxins. EPA proposed this limit to protect
public health and the environment from unreasonable risks of exposure to dioxins.
EPA also proposed to exclude the following from the numeric limit and monitoring
requirements: treatment works with a flow rate equal to or less than one million gallons per day
and certain sewage sludge-only entities that receive sewage sludge for further processing before
its application to land. We based this exclusion on the small amount of sewage sludge that these
facilities handle.
In December 1999, EPA also proposed not to regulate dioxins in sewage sludge that is placed in
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a surface disposal unit or fired in sewage sludge incinerator on the basis of separate risk
assessments for those management practices. EPA made a final decision to sustain that
determination in December 2001.
Developments Since Proposal
In 2001, EPA conducted a survey to update its information on the concentrations of dioxins in
sewage sludge. The Agency also performed a revised risk assessment for dioxins in land-applied
sewage sludge. We are seeking comments on the updated survey and the findings of the revised
risk assessment, both of which are presented in this NOD A. The NODA also summarizes a
survey of dioxins in sewage sludge conducted by the Association of Metropolitan Sewerage
Agencies .
In addition, the NODA discusses the implications of the new data and revised risk assessment on
the proposed limit, monitoring requirements, small entity exclusion and projected cost of the
proposed regulation. Finally, the NODA discusses how our risk estimates for the highly-exposed
population could be affected by the Agency's Draft Dioxin Reassessment if it becomes final
before we complete this rulemaking.
Additional Information
For additional information, contact Alan B. Hais at (202) 566-1106 or Alan B. Rubin at (202)
566-1125.
You can find other sewage sludge information on the Internet at
http://www.epa.gov/waterscience/biosolids/.
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