Understanding the EPA Draft Sewage Sludge Risk Assessment for PFOA and PFOS

On January 14, 2025, the U.S. Environmental Protection Agency (EPA) released its Draft Sewage Sludge Risk Assessment for Perfluorooctanoic Acid (PFOA) and Perfluorooctane Sulfonic Acid (PFOS). The document was opened for public comment on January 15, 2025.
In some states, more than 50% of sewage sludge generated from publicly owned treatment works (POTWs) has been land-applied in recent years. Due to their impact on food crops, animal products, and drinking water, this document is critical to understanding the potential public health risks originating from PFAS-contaminated land-applied sludge or biosolids, as well as determining the need to adapt waste management practices based on the assessment.
Continue reading for more about the draft risk assessment for PFOA and PFOS in sewage sludge - including key details, analysis and fingerprinting, how Battelle can help and what's coming next.
About the Draft Risk Assessment
The EPA Draft Sewage Sludge Risk Assessment is a preliminary version of a technical report that estimates the risk to public health from the surface disposal of sludge or application of biosolids. It examines the way PFAS in biosolids might affect groundwater near application sites, as well as impact livestock or agricultural products grown on land using biosolids as soil amendments.
Why It's Important
The Draft Risk Assessment is not a regulatory standard, meaning that legal consequences won’t arise from the document. However, it is still significant because it highlights the potential risk to public health and provides state and local regulators with the risk assessment framework for evaluating PFAS in biosolids. Consequentially, this attention may lead to stakeholder interests that will push the waste management and environmental industries towards reevaluating the impacts of their sludge disposal or biosolids application practices.
The Spotlight Is on Sludge
While the Draft Risk Assessment may remain in draft form for an extended period, it will still attract stakeholder attention. This means that municipalities, businesses, and other stakeholders should be aware of the potential implications and start thinking proactively about the issues raised.
Beyond public health risks, other key factors to keep in mind include:
- Potential upcoming regulatory actions from the federal, state or local regulatory bodies
- Legal vulnerabilities stemming from PFAS-containing sludge or biosolids
- Technical challenges while implementing new waste management practices
Additionally, different states may move ahead of the federal government in addressing these issues, especially in regions like New England and California. For example, the Minnesota Pollution Control Agency released the Minnesota Biosolids PFAS Strategy on MPCA Jan. 17, 2025. Maine has recently banned the land application of biosolids, unless the biosolids can be demonstrated to be PFAS free. This indicates that even if the federal government takes time to finalize its conclusions, state regulators and legislatures may act more quickly.
Who Is Impacted?
The new Draft Risk Assessment is highly relevant to several key groups of stakeholders from government and commercial sectors alike.
Municipalities
Municipalities and their service providers, including consultants that manage biosolids or sewer sludge, are significantly impacted by the Draft Risk Assessment. Local governments are responsible for managing biosolids, often in collaboration with contractor companies and need to be aware of the potential risks and start thinking proactively about waste management practices.
State Regulators
State regulators involved in residuals management and waste management strategies will also have an interest in the draft assessment. They’re likely to be the ones regulating biosolids and ensuring compliance with any new guidelines or standards that may emerge.
Real Estate Transactions and Landowners
Landowners or property managers who allow the land application of biosolids may also be affected. The draft assessment suggests that applying biosolids to farms as fertilizer could pose significant health risks, implying unacceptable risks from eating produce grown on such lands.
Landowners could face liability issues due to contaminated land resulting from the application of biosolids. These stakeholders may want to reconsider their practices and be aware of the potential liabilities, as well as conduct due diligence to mitigate future risks.
Agricultural
Agricultural stakeholders, including small-scale agricultural practices or producers, could be directly impacted. The draft assessment warns that using biosolids as fertilizer could lead to PFAS-contaminated land and pose health risks to livestock and crops, bringing significant implications for food safety and agricultural practices.
Testing Biosolids, Sludge and Source Material
While not federally required at this point, affected parties may want to identify and track major sources of PFAS in their sewershed to see the extent of their problem. Keep in mind that some states may require testing - check with your localities to confirm.
So, how can Battelle help? If you’ve read to this point, you may be wondering how or where to get started. Our experts are here to guide you through the process of identifying and tracking these sources. Here’s some key areas to consider.
Analytical Testing
When it comes to managing biosolids and sludge, analytical testing is a crucial first step. Analytical testing involves examining the material to determine the presence and concentration of PFAS. This process helps stakeholders understand the scope of the problem and identify potential risks associated with the use of biosolids.
Analytical methods used to test PFAS in sewer sludge or biosolids include:
- EPA Method 1633: For high fidelity data suitable for independent validation
- Total Oxidizable Precursor (TOP) Assay: For assessing unidentified PFAS precursors in biosolids or sludge
By conducting thorough analysis, municipalities, businesses, and other stakeholders can make informed decisions about how to manage and mitigate these risks.
Explore our Accredited PFAS Laboratory
Source Fingerprinting
Another important aspect of testing is source fingerprinting, which enables the identification of the origins of PFAS in biosolids and sludge. This method helps stakeholders trace the contaminants back to their sources, allowing for more targeted and effective management strategies.
Tools and methods used for source tracking on sludge and biosolids include:
- Battelle’s PFAS Signature®: Assess and trace PFAS sources in biosolids and sludge
- Non-Targeted Analysis/Suspect Screening Analysis: Screen for less common PFAS
Once sources of PFAS are identified, stakeholders can implement measures to reduce or eliminate these sources to mitigate potential risks.
Management and Strategy
Developing a comprehensive management strategy is essential for effectively handling biosolids and sludge. This strategy should include regular testing, source identification, and appropriate disposal or treatment methods. The Draft Risk Assessment highlights the need to retool waste management practices, as traditional methods such as land application, incineration, and turning sludge into biosolids may pose significant risks.
By adopting proactive waste management for biosolids and sewer sludge, stakeholders can better protect public health and the environment.
Explore PFAS Consulting and Strategic Management
What’s Next?
The EPA’s final risk assessment is expected to bring significant changes, but it's important to note that this version is still a draft. Although the federal government is likely to delay in finalizing its conclusions, some states are already considering the implications of this assessment, and your region might be moving faster than the federal government in addressing these issues.
For state and local governments, this draft risk assessment may raise questions from communities, waste managers and other stakeholders. These groups will be keen to understand the potential impacts on human health and the environment, as well as the necessary steps to comply with any future regulations. State and local authorities may want to provide clear, transparent information about the draft assessment and its implications.
The Battelle Advantage
Battelle works diligently to partner with State, Federal, and commercial clients to support method development, sample processing, and PFAS analytical measurement to better understand how PFAS moves from biosolid-amended farm fields through the environment and food chain. Explore some of our recent work supporting the State of Maine in the Journal of Agricultural and Food Chemistry.
With our accredited PFAS laboratory, proprietary source tracking tools, project management acumen and industry-leading expertise, count on Battelle to help you confidently reduce risk and prepare for upcoming sludge or biosolids regulations.
Featured Expert

Jon Petali, Ph.D., DABT
Human Health Risk Assessor
Leveraging a Ph.D. and 7 years of experience across academia and state government, Jonathan applies his deep environmental toxicology expertise to help clients address PFAS and other emerging chemical contamination issues through robust risk assessment, research and risk communication.
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