Per- and Polyfluoroalkalyl Substances (PFAS) are not directly generated at wastewater treatment plants (WWTPs) but enter through influent from industrial, commercial and domestic sources. Standard sludge treatment methods, such as digestion, lime treatment, thermal drying and composting, do not remove PFAS. As a result, municipal biosolids often contain trace amounts or even elevated levels of these "forever chemicals."

The most common PFAS compounds in sludge are perfluoroctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA). When wastewater solids containing PFAS are recycled as biosolids, incinerated or landfilled, they can release these "forever chemicals" into the environment. The U.S. Environmental Protection Agency (EPA) has set Maximum Contaminant Levels (MCLs) for six PFAS compounds in drinking water. Though the agency has developed a testing method for PFAS in wastewater, no federal regulations or guidelines limit PFAS levels in wastewater.

In response, some states have started taking proactive steps concerning biosolids management. This blog post explores the EPA's actions to address PFAS in wastewater and biosolids and ways Fehr Graham helps communities reduce PFAS exposure and protect the environment.

PFAS in wastewater and biosolids management

The PFAS strategic roadmap was developed in 2021 to counter PFAS contamination. The roadmap takes a comprehensive approach to:

• Limiting PFAS from entering air, land and water.
• Accelerating the cleanup of PFAS contamination.
• Investing in research, development and innovation to understand these "forever chemicals."

Limiting PFAS in wastewater

Once PFAS-bearing waste enters wastewater systems, treatment plants are responsible for addressing the contamination. However, Publicly Owned Treatment Works (POTWs) lack the capacity to remove PFAS because of the sheer volume of wastewater they process.

​Through the PFAS Strategic Roadmap, the U.S. EPA plans to address PFAS in wastewater.

EPA actions for limiting PFAS in wastewater

Measuring PFAS in wastewater. In January 2024, the EPA released three methods to better measure PFAS in the environment. Final EPA method 1633 tests 40 PFAS in wastewater, biosolids, surface water, groundwater and other sources. Final EPA method 1621 screens for the presence of chemical substances containing carbon-fluoride bonds, including PFAS, in wastewater. Other Test Method (OTM-50) measures 30 volatile fluorinated compounds in the air.

Water quality criteria and benchmarks. In September 2024, the EPA published the final science-based water quality concentrations for 10 PFAS compounds. States can use these criteria and benchmarks to develop water quality standards for implementing other Clean Water Act programs, such as wastewater discharge permits.

Nationwide PFAS study at wastewater treatment facilities. Through the two-year study, the EPA plans to collect and analyze nationwide data on PFAS in the influent, effluent and biosolids at wastewater treatment plants.

Managing PFAS in biosolids​

Biosolids are defined as sewage sludge that has been treated to meet regulatory standards and is suitable to be applied on land as a soil conditioner or fertilizer. The EPA regulates the disposal and use of biosolids under the Clean Water Act. The agency has taken a few steps to research, restrict and remediate PFAS in biosolids.

EPA actions for limiting PFAS in biosolids

Draft sewage sludge risk assessment for PFOA and PFOS. In January 2025, the agency released a draft risk assessment of the potential human health risks associated with PFAS chemicals in biosolids. The preliminary findings of the assessment indicate that there can be human health risks if the amount of PFAS in biosolids exceeds EPA’s acceptable thresholds.

National sewage sludge survey. The EPA is planning to conduct the Biosolids Program’s next National Sewage Sludge Survey (NSSS). The survey will focus on gathering national concentration data on PFAS in sewage sludge. The generated data will help inform future risk assessments and risk management actions for biosolids.

Limiting PFAS in wastewater and biosolids management is still in the early stages. Without clear and specific guidelines for sampling, testing and monitoring PFAS in wastewater, communities may find it challenging to implement source control and effective treatment methods. Partnering with a trusted team of wastewater engineers can help address the contamination.

How Fehr Graham can help your community limit PFAS in wastewater and biosolids management ​​ 

At Fehr Graham, we are committed to helping communities address PFAS contamination in wastewater and biosolids management. From planning and developing effective treatment solutions to securing funding for system upgrades, we are a one-stop shop for all your wastewater engineering requirements.

Jennifer Buholzer, PE, is a Project Engineer who works on everything from water and wastewater projects to transportation and park projects. She develops relationships with our clients to help them find the most affordable and sustainable solutions. Jen is knowledgeable, results-driven and enthusiastic, offering training and webinars and serving as a conference speaker at dozens of events annually. Reach her at This email address is being protected from spambots. You need JavaScript enabled to view it..