Monthly newsletter Material Concerns: Legal Updates on Substances of Emerging Concern keeps clients informed on the latest legal, regulatory and scientific developments related to substances of emerging concern. Each issue delivers concise, actionable insights to help companies navigate the evolving landscape of environmental law.

Comment Period Closes on EPA’s Draft PFAS in Biosolids Guidance Memorandum

By Joseph Zaleski 

The public comment period for the U.S. Environmental Protection Agency’s (EPA) Draft Guidance for Reducing Risk from Perfluorooctanoic Acid (PFOA) and Perfluorooctane Sulfonic Acid (PFOS) in Biosolids closed on October 5 after a 30-day extension by the agency. The draft guidance reflects a notable shift from EPA’s 2025 draft risk assessment, replacing the earlier document’s quantitative risk estimates with voluntary, qualitative risk-management recommendations.

EPA published its draft PFAS in biosolids guidance memorandum in June 2026. It identifies voluntary recommendations for reducing potential risks from PFOS and PFOA in land-applied biosolids and is addressed to key stakeholders, including public wastewater treatment plant operators, landowners, farmers, state and tribal drinking water authorities, as well as the general public.

EPA typically uses the term “biosolids” to refer to nutrient-rich sewage sludge that has been generated at a wastewater treatment facility and meets existing regulatory treatment standards for land application as a soil amendment or fertilizer. As regulatory scrutiny over PFAS has increased in recent years, federal and state regulators have paid more attention to the presence and potential ecological and human health impacts of PFAS in biosolids applied to land.

EPA’s 2019 PFAS Action Plan proposed developing a draft risk assessment to evaluate potential risks posed by the presence of PFOA and PFOS in land-applied biosolids. In 2025, the Biden Administration released a draft of that risk assessment, which found, among other things, that there may be human health risks exceeding the agency’s acceptable thresholds in some scenarios when land-applied biosolids contain PFOS or PFOA in excess of one part per billion. The Trump Administration twice extended the comment period for the 2025 draft risk assessment and has taken no further action to rescind or finalize the document. 

EPA’s 2026 draft biosolids guidance memorandum now identifies “a number of serious flaws” in the 2025 draft risk assessment that have “caused confusion among the public and the regulated community,” and, importantly, does not propose to adopt specific numeric guidelines or standards for PFOS or PFOA in biosolids. Instead, the draft guidance memorandum provides qualitative recommendations, including suggestions that farmers and landowners avoid land-application of biosolids near fishable waters or other surface waters used as sources for drinking water and that wastewater treatment plants monitor for PFOS and PFOA concentrations in sewage sludge. 

Comments submitted on EPA’s draft guidance have requested clarification on the agency’s intention to publish or finalize specific numeric or risk characterization standards for PFOS and PFOA in biosolids. Separately, EPA’s Science Advisory Board discussed the draft PFAS in biosolids guidance memorandum at its October 19 meeting and called for a briefing with EPA officials to discuss the purpose and intended future uses of the document.

While EPA continues to assess this issue, individual states continue to develop their own approaches to PFAS in biosolids. As EPA’s draft PFAS in biosolids guidance memorandum notes, some states, including Michigan, Wisconsin, Minnesota, Colorado, Maryland and Virginia, have adopted different types of tiered approaches to monitoring and reducing PFAS concentrations entering sewage sludge at the industrial source, as well as setting standards for PFAS in biosolids to be applied on land. Other states, including Washington, Oregon and Florida, require monitoring of PFAS concentrations in sewage sludge as they continue to develop biosolid programs. Finally, Maine and Colorado have taken legislative action to ban outright any land-application of sewage sludge. The result is likely to remain a patchwork regulatory landscape in which the requirements applicable to biosolids may depend substantially on where they are generated and ultimately managed or land-applied. Wastewater treatment plants, biosolids managers, landowners, and other affected entities should therefore continue to monitor both EPA’s next steps and rapidly evolving state requirements.

California Moves to Add Three PFAS to Proposition 65 List

By Kate Klaus

The California Office of Environmental Health Hazard Assessment (OEHHA) has announced its intent to add three PFAS to the list of chemicals regulated under Proposition 65, according to notices published October 30, 2026.

The chemicals proposed for listing are:

• perfluorodecanoic acid (PFDA) and related salts,
• perfluorohexanoic acid (PFHxA) and related salts, and
• perfluorobutanoic acid (PFBA) and related salts.

The proposal rests on OEHHA’s position that the three PFAS “meet the criteria for listing as known to the state to cause reproductive toxicity under Proposition 65, based on findings by the US EPA.” Interested parties may submit comments on the proposal through November 30, 2026.

If finalized, the listings would add PFDA, PFHxA and PFBA to the three PFAS already on the Proposition 65 list: perfluorooctanoic acid (PFOA), perfluorooctane sulfonate (PFOS), and perfluorononanoic acid (PFNA) and its salts.

Proposition 65 is a right-to-know law that requires businesses to provide clear and reasonable warnings for products sold in California that can expose consumers to chemicals on the Proposition 65 list. A warning is not required, however, if a business can show that the exposure poses no significant risk of cancer or reproductive harm. OEHHA often establishes safe-harbor levels to guide these determinations, but it has not set any for the PFAS already listed.

Proposition 65 may be enforced by the California attorney general and certain local prosecutors, as well as by private plaintiffs, who must first serve a 60-day notice of the alleged violation on the business and the relevant public enforcers. Private enforcement involving PFAS has been substantial, with nearly 750 such notices served for PFOA, PFOS and PFNA as of October 2026.

If finalized, the proposed listings would expand the range of PFAS subject to Proposition 65 enforcement. Businesses found in violation of Proposition 65 face injunctive relief and civil penalties of up to $2,500 per violation per day.

Congress Introduces Drinking Water Microplastics Monitoring Bill

By Jennifer E. Hackman

On October 29, 2026, U.S. Reps. Rashida Tlaib (D-Mich.) and Bonnie Watson Coleman (D-N.J.) introduced the Monitor Microplastics Now Act, legislation that would require the U.S. Environmental Protection Agency (EPA) to monitor microplastics and nanoplastics in drinking water.

According to its sponsors, the legislation is a response to EPA’s recently released draft sixth Unregulated Contaminant Monitoring Rule (UCMR 6), which would require monitoring for numerous contaminants under the Safe Drinking Water Act but, as currently drafted, would not include microplastics or nanoplastics.

The bill would direct EPA to:

• Monitor microplastics and nanoplastics in drinking water systems;
• Include microplastics and nanoplastics among the contaminants monitored under federal drinking water programs; and
• Reevaluate and justify EPA’s decision to exclude those substances from ongoing monitoring initiatives.

Importantly, the legislation would not establish any drinking water standards, maximum contaminant levels, emission limits, or product restrictions. Rather, it would focus on generating occurrence and exposure data through federal monitoring.

Environmental regulation often follows a predictable progression: monitoring, risk assessment, occurrence studies, and then potential regulation. At present, the bill remains in the early stages of the legislative process and has not advanced beyond introduction. Nonetheless, the bill’s introduction signals continuing pressure on EPA to address microplastics under the federal drinking water program.

The proposal also emerges amid broader scrutiny of EPA’s treatment of microplastics. Recently, the Science Advisory Board highlighted questions regarding the agency's approach to microplastics in connection with its contaminant prioritization and evaluation programs. 

As with PFAS, regulators face the challenge of developing reliable analytical methods, understanding environmental fate and transport, and identifying meaningful exposure thresholds before determining whether and how comprehensive regulation may be appropriate.

If enacted, the bill could produce a significant expansion of federal data regarding microplastic occurrence in drinking water systems nationwide. Such information could:

• Establish baseline occurrence data for future risk assessments;
• Support future regulatory determinations under the Safe Drinking Water Act;
• Identify geographic areas of elevated contamination;
• Increase public scrutiny of plastic waste streams and wastewater discharges; and
• Inform future federal and state policymaking. 

While the bill itself would not directly regulate manufacturers or impose reporting obligations on industrial entities, it could have substantial downstream consequences for regulated entities and other stakeholders.

Expanded monitoring may generate data relevant not only to future regulatory decisions, but also to litigation and other claims involving microplastics. As seen in PFAS litigation, the availability of monitoring data can become a catalyst for regulatory investigations, nuisance claims, product liability allegations, natural resource damage actions, and other environmental claims. Companies whose products, operations or waste streams may involve microplastics or nanoplastics should therefore continue to monitor both the legislation and EPA’s evolving approach to these emerging contaminants.

EPA Launches PFAS TECH Initiative to Accelerate PFAS Treatment and Destruction Technologies

By Jennifer E. Hackman

On October 26, 2026, the U.S. Environmental Protection Agency (EPA) announced the launch of the agency-wide PFAS Technology Evaluation, Coordination, and Harmonization (PFAS TECH) initiative, a new strategy aimed at accelerating the development, evaluation and deployment of technologies designed to treat and destroy PFAS.

The initiative reflects EPA’s growing focus on the practical challenges associated with managing PFAS-contaminated drinking water, wastewater, landfill leachate, biosolids, and industrial waste streams. Rather than focusing on new regulatory standards, PFAS TECH is intended to coordinate research efforts across the agency and support the advancement of technologies capable of removing or destroying PFAS compounds. 

According to EPA, PFAS TECH will evaluate and promote promising treatment and destruction technologies, including:

• Foam fractionation;
• Supercritical water oxidation;
• Hydrothermal alkaline treatment;
• Thermal destruction technologies; and
• Other emerging PFAS treatment methods.

The initiative is also expected to support pilot projects, demonstration programs, and collaboration among federal agencies, researchers, utilities and private-sector stakeholders. 

For companies facing PFAS-related compliance, remediation or litigation issues, the initiative may have significant implications. Although PFAS TECH does not impose new regulatory requirements, EPA’s endorsement and evaluation of specific technologies could influence future cleanup expectations, permit conditions and remediation standards. 

As EPA identifies technologies it considers effective and practicable, those technologies may increasingly serve as benchmarks in enforcement actions, remediation negotiations, cost-recovery disputes, and toxic tort litigation. 

The launch of PFAS TECH signals EPA's recognition that the next phase of PFAS regulation extends beyond detection and monitoring to the practical question of how contamination will be managed and remediated. While the initiative does not create new legal obligations, companies addressing PFAS liabilities should closely monitor EPA’s evaluations and recommendations, as they may shape future regulatory expectations and standards of care.