Why Aren’t PFAS Compounds in Land Applied Biosolids Regulated By EPA?

As of mid-June  2025, most agricultural stakeholders across the country have become aware of claims by clean water advocates, and an emerging acknowledgment by state water quality regulators, that the beneficial use of municipal sewage treatment plant residual waste by land-application as a soil supplement and nutrient source (“bio-solids”) brings with it a newly-recognized ancillary risk:  Potential soil and adjacent ground water contamination by high levels of per- and polyfluoroalkyl substances (PFAS) concentrated in biosolids. According to the U.S. Environmental Protection Agency (EPA), in 2023 approximately 60% of all U.S.-generated biosolids were land-applied.

As for the impact of potential PFAS soil and ground water contamination, EPA states, “current scientific research suggests that exposure to certain PFAS may lead to adverse health outcomes. However, research is still ongoing to determine how different levels of exposure to different PFAS compounds can lead to a variety of health effects. Research is also underway to better understand the health effects associated with even low levels of exposure to PFAS over long periods of time, especially in children.”

Eliminating the continued incorporation into consumer products and packaging of PFAS compounds considered the most dangerous to our environment and health (perfluorooctanoic acid (PFOA) or perfluorooctane sulfonic acid (PFOS)) is an important first step in controlling the growth of ambient environmental PFAS loads.  That task is being slowly but steadily undertaken by federal and a few state regulators.

However, ultimately reducing those loads will also require alterations to current practices which simply recycle existing environmental loads, primarily in water but also soil and air. Part of this task will be laid at agriculture’s feet. Legal changes will undoubtedly be forthcoming shortly to the permitted land application of biosolids—generated from thousands of wastewater treatment plants servicing millions of people.  Farmers are the owners of the majority of land on which land application occurs and are the recipients of this residual waste’s beneficial use.

What we have seen over the last few years has been a smattering of individual state government actions restricting and limiting the practice of land application of biosolids in various ways. This has been seen primarily in states that have become motivated to, and have been politically capable of, legislative amendment of statutes or state agency amendment of regulations—usually the result of one or more high profile in-state cases of soil and ground water PFAS contamination suspected to be caused by biosolids.  Some extreme instances have produced state regulatory agency quarantine orders of entire tracts of farmland, preventing or limiting continued agricultural production.

A compilation of those individual state actions has been assembled by a national environmental consulting firm, ALL4 , and is publicly available at this link: State-by-State Regulatory Update (March 2025 Revision) (see Table 2 – State Water Regulation Highlights).  As this table’s data reveals, PFAS regulation in land-applied biosolids thus far has been a patchwork of ad-hoc measures pursued by individual states using their own state legal authority.

Complicating operations for those who engage in land-application, and those charged with regulating pollutants in residual waste, ground water and soil, is the fact that biosolids are now frequently being transported across state lines enroute from the source (a wastewater treatment facility) and the land-application site (a farm).  This creates significant legal hurdles to a unified and consistent regulatory scheme that aspires to follow the concentration, handling, and potential environmental reintroduction of PFAS compounds— i.e. regulating the life cycle of biosolids “from cradle to grave.”

Can EPA take nationwide action via the Clean Water Act (CWA), since these PFAS compounds are land-applied in accordance with the CWA’s National Pollutant Discharge Elimination System (NPDES) permitting program?  After all, the NPDES was designed for nationwide application, with some allowed state-by-state variability.

The answer is yes. The legal tool through which EPA can begin to regulate PFAS content on a national basis in our wastewater systems, and resulting biosolids, lies in the broad scope of the Clean Water Act.  To date however, EPA has provided guidance documents to states in taking their own actions—which are suggested best  management practices and non-binding.

EPA adding a new pollutant to those already identified and regulated in biosolids is ultimately controlled by the text of Section §405(d) (33 U.S.C. §1345(d)) of the Clean Water Act (“Disposal or Use of Sewage Sludge”), as supplemented by the regulations at 40 CFR Part 503. The law requires EPA to establish numeric limits and mandatory management practices to protect public health and the environment from the reasonably anticipated adverse effects of designated pollutants during the use or disposal of biosolids. Section 405(d) also requires EPA to review its biosolids regulations at least every two years to identify additional pollutants that may be present in biosolids and then promulgate regulations for those pollutants if sufficient scientific evidence shows they may adversely affect public health or the environment.

Since its emergence as a pollutant of concern, EPA has not yet established numeric limits, monitoring, or reporting requirements for PFAS in biosolids or in land-application. EPA’s  “PFAS Strategic Roadmap” progress reports state that by winter 2024 it would complete a risk assessment for PFAS in biosolids for use in determining whether to regulate them.

On January 15, 2025, EPA commenced that process by publishing in the Federal Register the following document, “Draft Sewage Sludge Risk Assessment for Perfluorooctanoic Acid (PFOA) and Perfluorooctane Sulfonic Acid (PFOS). After multiple extensions, the public comment period is now scheduled to close on August 14, 2025.  The public comments lodged so far are available at the following regulatory docket: EPA-HQ-OW-2024-0504.

The findings in EPA’s draft risk assessment includes the following:

“The EPA’s draft risk assessment describes the potential human health and environmental risks associated with land application, surface disposal, and incineration of sewage sludge containing PFOA or PFOS, which are the use and disposal practices regulated under CWA section 405(d).
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For the land application scenarios, the EPA modeled potential PFOA and PFOS exposures and estimated human health risks to those living on or near impacted properties under three hypothetical scenarios: (1) application to a farm raising dairy cows, beef cattle, or chickens (pasture farm scenario), (2) application to a farm growing fruits or vegetables (food crop farm scenario),⁾ and (3) application to reclaim damaged soils such as an overgrazed pasture (reclamation scenario).
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The draft risk assessment indicates that there are potential risks to human health to those living on or near impacted properties or primarily relying on their products from land application.
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After the public comment period has closed, the EPA will. . . prepare a final risk assessment. . . If the final risk assessment indicates that there are risks above acceptable thresholds when using or disposing of sewage sludge, the EPA expects to propose a regulation under CWA section 405 to manage PFOA and/or PFOS in sewage sludge to protect public health and the environment.”

This risk assessment was prompted at least in part by last year’s June 6, 2024, filing of a federal lawsuit in the U.S. District Court for the District of Columbia seeking to compel EPA to establish regulatory standards for PFAS in land-applied bio-solids. Farmer, et al. v. EPA, No. 24-cv-1654.  The following excerpt (paragraphs 10 and 11 of the Complaint) conveys the objective of the litigation succinctly:

10. This suit seeks to remedy the ongoing harms caused by EPA’s failure to comply with its mandatory CWA duty to identify and regulate these dangerous substances in sewage sludge. EPA’s failure has enabled the land application of PFAS-laden sewage sludge on millions of acres of land, harming Plaintiffs and people across the country by exposing them to PFAS and depriving them of the procedures guaranteed to them by the Clean Water Act for timely identification and regulation of harmful substances in sewage sludge.

11. There are no national requirements to test sewage sludge for PFAS or warn farmers that they could be using contaminated sludge. This is an urgent and pervasive problem.

Not surprisingly, the lawsuit has moved slowly, and various motions have consumed the past year.  The coming year will undoubtedly bring significant legal/regulatory and operational changes for wastewater processors, farmers, landowners, and other agricultural stakeholders across the country involved in land-applying biosolids. The long-awaited emergence of PFAS regulation in bio-solids is on its way, albeit comparatively slowly.

Author:

Brook Duer