The U.S. Environmental Protection Agency (EPA) has released draft guidance to help wastewater utilities, farmers, landowners, and the public better manage potential risks associated with PFAS in biosolids, with a particular focus on PFOA and PFOS.
The proposed guidance forms part of the agency’s broader lifecycle strategy for tackling per- and polyfluoroalkyl substances (PFAS) and is intended to provide practical recommendations while gathering public feedback before any future regulatory decisions are made.
Rather than introducing new requirements immediately, the EPA is opening a 60-day public consultation following publication in the Federal Register.
The agency says stakeholder input will help shape the next phase of its approach, balancing public health protection with the continued management and beneficial reuse of biosolids.
Understanding biosolids
Biosolids are the treated solid materials produced during wastewater treatment after liquids have been separated from sewage. Once treated to meet federal standards under the Clean Water Act, these materials can be used as soil amendments or fertilisers.
Across the United States, biosolids are commonly applied to agricultural land, forests, tree farms, golf courses and turf farms. Some products are also packaged for retail sale for use on domestic lawns and gardens.
Although the terms “biosolids” and “sewage sludge” are often used interchangeably, the EPA distinguishes biosolids as treated sewage sludge that meets regulatory standards for land application.
The agency notes that some wastewater treatment plants also receive industrial wastewater alongside domestic sewage, meaning contamination levels can vary significantly depending on local sources.
Why PFOA and PFOS remain a concern
PFOA and PFOS are among the most widely studied members of the PFAS family, a group of highly persistent synthetic chemicals often referred to as “forever chemicals” because they break down very slowly in the environment.
Scientific research has linked exposure to PFOA and PFOS with a range of adverse health effects, leading to increasing regulatory scrutiny in recent years.
While many major manufacturers phased out domestic production and import of PFOA under the EPA’s 2010/2015 PFOA Stewardship Program, some production and uses continue outside those participating companies, and certain applications of PFOS remain in use.
The EPA emphasises that statewide monitoring has detected PFOA and PFOS in some sewage sludge, but contamination levels differ considerably.
Draft guidance focuses on practical risk reduction
The EPA’s latest proposal is designed to help reduce exposure to PFOA and PFOS where biosolids are applied to land.
Among the recommendations in the draft guidance are avoiding the application of biosolids near waterways, preventing their use on land where children regularly play, and limiting their use on crops with a greater likelihood of direct human exposure.
The agency also recognises the continued role that treated biosolids can play in agriculture when managed appropriately. Land application remains a common practice for recycling nutrients contained within treated sewage sludge, supporting soil health while reducing waste sent to landfills.
EPA says the guidance is intended to provide practical advice that wastewater utilities, farmers and land managers can implement while longer-term policy decisions continue to be evaluated.
EPA seeks broader scientific input
The agency says its new draft guidance follows extensive engagement with wastewater utilities, agricultural stakeholders, scientists and other interested groups.
According to the EPA, feedback received on a previous draft risk assessment suggested that several assumptions did not adequately reflect real-world conditions.
Stakeholders argued that earlier modelling relied heavily on data from highly contaminated industrial sites and used risk calculations that some independent scientists questioned.
The agency also heard concerns that previous assessments did not sufficiently account for research from communities where biosolids have been applied to land for many years without evidence of widespread impacts.
By publishing the new draft guidance, the EPA says it is taking a more transparent approach to gathering scientific evidence and public feedback before determining future actions on PFAS in biosolids.
