Member Pipeline - Regulatory - Alert (RA 03-11)
To: Members & Affiliates, Biosolids Management Committee
From: National Office
Date: October 24, 2003
Subject: EPA TAKES ‘NO ACTION’ ON DIOXINS IN LAND APPLIED BIOSOLIDS
Reference: RA 03-11
Printer friendly versionOn October 17, 2003, the U.S. Environmental Protection Agency (EPA or the Agency) made its final determination regarding dioxin and dioxin-like compounds (dioxins) in land-applied biosolids, finding that neither numerical limitations nor requirements for management practices are currently needed to protect human health or the environment from dioxins in land-applied biosolids. Citing low predicted risks, even to the most highly exposed individuals, and declining concentrations of dioxins in biosolids, EPA concluded that the existing Part 503 regulations are adequately protective. EPA's final action was governed by an April 1, 2002 consent decree and settlement between AMSA, the Natural Resources Defense Council (NRDC), and citizen plaintiffs in a thirteen-year-old lawsuit over EPA’s Clean Water Act biosolids regulations, Gearhart v. Horinko (Gearhart). EPA originally was required to finalize the regulations by December 15, 2001 under the Gearhart Consent Decree. After extensive negotiations and various deadline extensions, the AMSA/NRDC/EPA agreement allowed EPA to take public comment on new dioxin data, and gave EPA an October 17, 2003 deadline to finalize the regulations. A copy of the notice and supporting materials can be found on EPA’s website at: http://www.epa.gov/waterscience/biosolids/. EPA’s final decision was published in the October 24, 2003 Federal Register (68 Fed. Reg. 61084).
AMSA filed extensive comments on EPA’s 1999 proposal to establish numeric limits for dioxins in land-applied biosolids and undertook a survey of dioxins concentrations in biosolids in an effort to improve the information EPA was using as the basis for its rulemaking. Since receiving the results of its survey in 2001, AMSA has asserted that the demonstrated decline in dioxins concentrations in biosolids, confirmed by EPA’s own survey, and the overall low concentrations found nationwide, support a no action determination. When EPA published its notice of data availability in 2002 detailing the results of its revised risk assessment, AMSA conducted a thorough review of EPA’s risk assessment methodology. Again, AMSA asserted that based on the demonstrated low risk to even the most highly exposed individuals, no further regulations were needed.
EPA’s Basis for Taking ‘No Action’
EPA’s decision not to regulate dioxins in land-applied biosolids
is based on the Agency’s finding that even the most highly exposed individuals,
farmers (and their families) who apply biosolids to their land and consume a
high percentage of their own agricultural products, are at a low risk of cancer
from dioxins in land-applied biosolids. In fact, EPA’s analysis shows that even
for this highly exposed population, 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.
Since the general population of the United States has even lower exposure to
dioxins in land-applied biosolids, the incremental cancer risk for the general
population is lower than the risk for the theoretical farm family.
In conducting the risk assessment for this rulemaking, EPA used the dioxin cancer slope factor (the incremental probability of developing cancer from exposure to a particular substance) from its 1985 guidance rather than the slope factor presented in the Agency’s Draft Dioxin Reassessment (a more stringent value). EPA reaffirms in the final rule that the reassessment is not a final document and that the Agency used the best available data published that meet the government’s Information Quality Guidelines. Significantly, EPA notes in the final rule that the Agency’s decision would have been the same using either cancer slope factor.
EPA also conducted a Screening Ecological Risk Analysis (SERA) on the risks to wildlife due to exposure to dioxins from land-applied biosolids. While EPA did not develop definitive risk estimates, the results of the SERA indicate that wildlife species should not be significantly impacted by dioxins in biosolids that are applied to the land.
In addition to characterizing the minimal risks to humans and wildlife associated with dioxins in biosolids, EPA also cites the results of its 2001 Dioxin Update to the National Sewage Sludge Survey, which indicate that dioxins levels in biosolids have declined since 1988. AMSA’s 2000/2001 Survey of Dioxin-like Compounds in Biosolids found similar trends of declining dioxins concentrations. Based on the additional regulatory controls that are being placed on sources of dioxins, EPA believes that this downward trend in dioxins concentrations will continue.
EPA Suggests Voluntary Dioxins Monitoring
The results of EPA’s survey infer that POTWs with higher
concentrations of dioxins in their biosolids may experience greater variability
in dioxins concentrations over time, and that higher dioxins levels may not
remain for a significant period of time. Using these survey findings and the
results of its risk assessment that indicate that risk to the highly exposed
individual remains low even when these elevated concentrations are considered,
EPA concluded that a regulatory monitoring requirement, in lieu of numeric
limits, was also not warranted.
While EPA is not imposing a regulatory monitoring requirement, EPA believes that there may be local benefits from establishing a voluntary monitoring and source investigation and identification program for dioxins in land-applied biosolids for some POTWs. Mixtures of dioxin and dioxin-like compounds have distinct patterns/profiles or fingerprints, and the source of dioxins entering a POTW can often be tracked to an individual source.
EPA is encouraging POTWs to consider implementing a voluntary biosolids dioxins monitoring and source identification program through an environmental management system (EMS) approach, such as the National Biosolids Partnership’s EMS program.
This decision on dioxins, while fulfilling a key component of the Agency’s consent decree obligations, is only one key step in the Agency’s ongoing efforts to review the biosolids regulations. Under the Gearhart case, EPA must complete its response to the July 2002 National Research Council (NRC) report on biosolids land application by January 2004. In its response, the Agency intends to lay out its plan for addressing the NRC’s recommendations over the coming years. EPA also must complete by January 2004 its review of pollutants in biosolids and determine whether any additional pollutants may require regulation. AMSA will be tracking these efforts and will provide members with updates on developments in future AMSA publications.
Again, a copy of the notice and supporting material is available at: http://www.epa.gov/waterscience/biosolids/.