EPA Proposes National Primary Drinking Water Regulations for Six PFAS Chemicals

Legal Intelligencer

(By Matt Wood and Mackenzie Moyer)

On March 14, 2023, the U.S. Environmental Protection Agency (EPA) provided a pre-publication version of a proposed National Primary Drinking Water Regulation Rulemaking that would regulate six polyfluoroalkyl substances (PFAS) under the Safe Drinking Water Act, 42 U.S.C. §§ 300f et seq (PFAS Rule). The proposed PFAS Rule would establish Maximum Contaminant Level Goals (MCLGs) and Maximum Contaminant Levels (MCLs) for perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS), two of the most common PFAS – a group of thousands of manmade chemicals used in various consumer, commercial, and industrial manufacturing processes since the 1940s – as individual contaminants. It would also establish a Hazard Index MCL for mixtures containing one or more of perfluorononanoic acid (PFNA), hexafluoropropylene oxide dimer acid and its ammonium salt (HFPO-DA, commonly known as GenX chemicals), perfluorohexane sulfonic acid (PFHxS), and perfluorobutane sulfonic acid (PFBS). Years in the making, the final PFAS Rule will be the first federally enforceable drinking water rule governing PFAS. EPA intends to finalize the PFAS Rule by the end of 2023.

PFAS have been used to make products water-, stain-, and heat-resistant and have been a key ingredient in some aqueous film forming foams (AFFF) used to extinguish flammable liquid fires (e.g., those that might occur on airports or military bases). PFAS are known as “forever chemicals” because they do not break down naturally in the environment. Due to these properties and their ubiquitous nature, PFAS have been found in various environmental media, such as groundwater (including drinking water), plants, animals, and in humans. Toxicity studies suggest that PFAS exposure can lead to adverse health effects.

For PFOA and PFOS, the proposed PFAS Rule sets MCLGs – non-enforceable health-based goals that represent the maximum concentration of a contaminant in drinking water at which there is no known or anticipated negative effect on a person’s health – at 0 parts per trillion (ppt). It sets the enforceable MCLs for PFOA and PFOS, which represent the maximum concentrations allowed in drinking water that can be delivered to users of a public water system and are informed by other factors (e.g., available treatment technologies and cost), at 4 ppt each.

The proposed PFAS Rule takes a different approach for PFNA, HFPO-DA (GenX), PFHxS, and PFBS by proposing regulation of these compounds as a mixture, because of their likely co-occurrence in drinking water, using a hazard index formula. The Hazard Index is calculated by dividing the concentration of each of the four PFAS compounds by its Health-Based Water Concentration (HBWC; 10 ppt for PFNA, 10 ppt for HFPO-DA (GenX), 9 ppt for PFHxS, and 2000 ppt for PFBS) and then adding the results together. A total value greater than 1.0 is an exceedance of the proposed Hazard Index MCL. For a more detailed explanation of the Hazard Index calculation, see EPA’s FAQ for Drinking Water Primacy Agencies, available here.

Prior to EPA’s announcement of the proposed PFAS Rule, the only federal drinking water guidance for PFAS were EPA’s 2022 interim Health Advisories for PFOA (0.004 ppt) and PFOS (0.02 ppt) and final Health Advisories for GenX (10 ppt) and PFBS (2,000 ppt), which are unenforceable standards that identify the concentration of PFOA and PFOS in drinking water at or below which adverse health effects are not expected to occur over a lifetime of exposure.

If finalized, and after a specified implementation period, the proposed PFAS Rule will require public water systems, including those in Pennsylvania, to monitor for each of the six PFAS discussed herein, notify the public of exceedances of the MCLs and/or Hazard Index MCL, and take action to reduce any exceedances in drinking water. Because the Safe Drinking Water Act does not regulate private wells, the proposed PFAS Rule does not apply to private well owners. EPA’s proposed PFAS Rule follows Pennsylvania’s recent adoption of state MCLs for PFOA (14 ppt) and PFOS (18 ppt) in January 2023. If the proposed PFAS Rule is finalized as written, Pennsylvania will have to lower its current MCLs for PFOA and PFOS and adopt standards for PFNA, HFPO-DA (GenX), PFHxS, and PFBS to ensure these standards are as at least as strict as the federal MCLs.

The proposed PFAS Rule is the latest action under President Joe Biden’s plan to combat PFAS pollution (fact sheet available here) and EPA’s 2021 PFAS Strategic Roadmap (available here), under which EPA is taking a “whole-of-agency approach” to address PFAS throughout its lifecycle. Consistent with this approach, EPA engaged in consultations with the public and sought input from other stakeholders, including public webinars, correspondence with the Science Advisory Board, and meetings with state, local, and tribal officials, to develop the proposed PFAS Rule.

To assist financially with addressing PFAS, the Bipartisan Infrastructure Law provides $9 billion to invest in drinking water systems impacted by PFAS and other emerging contaminants. $4 billion is earmarked for investment in Drinking Water State Revolving Funds and $5 billion will be made available to communities as grants through EPA’s Emerging Contaminants in Small or Disadvantaged Communities (EC-SDC) Grant Program, which is intended to promote access to safe and clean water in small, rural, and disadvantaged communities. In February 2023, EPA announced the availability of the first $2 billion of the EC-SDC funding.

The proposed NPDWR rulemaking will be subject to a 60-day public comment period upon publication in the Federal Register. EPA is also holding a public hearing on May 4, 2023, which members of the public can attend and provide verbal comments. More information on the public hearing can be found here.

In addition to the proposed PFAS Rule, EPA is moving to regulate PFAS under other federal programs, including a September 2022 proposal to designate PFOA and PFOS as hazardous substances under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). The proposed PFAS CERCLA Rule would implement certain reporting requirements for releases of PFOA or PFOS exceeding the applicable reportable quantity and would enhance EPA’s authority to address PFAS in the environment, including potentially reopening long-closed cleanup sites. The comment period for the PFAS CERCLA rule is closed and the rule could be finalized this summer.

In the months since the proposed PFAS CERCLA Rule, stakeholders have raised questions and concerns about how EPA intends to address enforcement for PFAS contamination under CERLCA. In March 2023, EPA held two listening sessions focused on these questions. The agency stated that it intends to focus its CERCLA enforcement on manufacturers, federal facilities, and other industrial parties that are significant sources of PFAS and does not intend to pursue water utilities and publicly owned treatment works, publicly owned and/or operated municipal solid waste landfills, farms that apply biosolids, and certain airports and fire departments. EPA said that it is considering summarizing its PFAS CERCLA enforcement discretion policy in a formal guidance document in the future. More information on the CERCLA enforcement listening sessions can be found here.

Babst Calland’s PFAS Work Group, including both environmental and litigation attorneys, continue to track PFAS technical and legal developments and are available to assist you with PFAS-related matters. For more information on this and other remediation matters, please contact Matthew C. Wood at (412) 394-6583 or mwood@babstcalland.com, Mackenzie M. Moyer at (412) 394-6578 or mmoyer@babstcalland.com, or any of our other attorneys in this practice.

Matthew C. Wood is Senior Counsel in Babst Calland’s Environmental Group. His practice encompasses a variety of legal matters arising under major federal and state environmental and regulatory programs, with a focus on issues involving government inquiries, environmental investigations, remediation, and related activities.

Mackenzie M. Moyer is an associate in Babst Calland’s Environmental Group. Her practice encompasses a broad range of environmental issues including state and federal permitting and regulatory compliance.

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Reprinted with permission from the April 6, 2023 edition of The Legal Intelligencer© 2023 ALM Media Properties, LLC. All rights reserved.