Climate change and environmental justice are currently dominating the conversation in the environmental legal community, but 2021 promises to be an extremely active year for one of the most challenging environmental issues of this era — the emergence of per- and polyfluoroalkyl substances (PFAS) as a significant public health concern. The U.S. Environmental Protection Agency (USEPA) demonstrated its continued commitment to implementing the national PFAS Action Plan by announcing on February 22 two important steps toward establishing federal drinking water standards for PFAS compounds under the Safe Drinking Water Act (SDWA).

First, on January 14, USEPA issued a pre-publication copy of the proposed fifth update to the Unregulated Contaminant Monitoring Rule (UCMR 5), which identifies unregulated compounds to be monitored by Public Water Systems[1] (PWSs). The UCMR 5 will require most PWSs around the country to test for and monitor 29 PFAS compounds in drinking water.[2] The document was subsequently re-issued on February 22, signed by Jane Nishida, named by President Biden to serve as acting administrator until a new administrator is confirmed.[3] The re-issued document appears to be identical to the January 14 version. This new version has been submitted for publication in the Federal Register.

Second, on January 15, USEPA issued the pre-publication copy of its “Announcement of Final Regulatory Determinations for Contaminants on the Fourth Drinking Water Contaminant Candidate List” (Regulatory Determination 4), which set forth USEPA’s final determination to regulate two of the most well-studied PFAS compounds, perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA). In addition, Regulatory Determination 4 announced USEPA’s intention to move forward with regulatory determinations on other PFAS compounds on the Candidate Contaminant List (CCL), and to render such determinations prior to the applicable statutory deadlines under the SDWA, where sufficient information is available to do so. Similar to the UCMR 5, Regulatory Determination 4 was re-issued on February 22, signed by Acting Administrator Jane Nishida, and appears to be identical to the January 15 version. This re-issued version has been submitted for publication in the Federal Register.

UCMR 5 Establishes Monitoring Requirements for 29 PFAS Compounds

The SDWA establishes standards for drinking water in PWSs, including “maximum contaminant levels” (MCLs), which are the enforceable primary drinking water standards established to protect human health. PFAS compounds are currently classified as unregulated contaminants since no federal standards have been established for any PFAS compounds. The SDWA requires USEPA to follow a multistep, risk-based approach for determining which contaminants should be subject to drinking water standards.

First, USEPA is required to publish a CCL every five years, identifying contaminants that are not subject to any proposed or promulgated drinking water regulations, but which are known or anticipated to occur in PWSs, and which may require regulation under the SDWA.[4] Second, every five years, USEPA must identify not more than 30 unregulated contaminants that must be monitored by PWSs to determine the frequency of occurrence of those contaminants in drinking water systems; this is the purpose of the UCMR program.[5] Third, USEPA is required to determine, every five years, whether or not to regulate at least five contaminants from the CCL.[6]

While no final federal drinking water standards have been issued for any PFAS compounds,[7] USEPA has been moving forward with its evaluation of certain PFAS compounds under its SDWA authority. The third Unregulated Contaminant Monitoring Rule (UCMR 3), published May 2, 2012, included six PFAS compounds on the CCL to be monitored by PWSs, including:

  • perfluorooctanesulfonic acid (PFOS)
  • perfluorooctanoic acid (PFOA)
  • perfluorononanoic acid (PFNA)
  • perfluorohexanesulfonic acid (PFHxS)
  • perfluoroheptanoic acid (PFHpA)
  • perfluorobutanesulfonic acid (PFBS)

The newly proposed UCMR 5 will expand the list of monitored PFAS compounds to 29.[8] Most PWSs will be affected by this proposed rule and will be required to monitor these compounds, subject to the availability of adequate Congressional appropriations and appropriate laboratory capacity.[9] The monitoring information required under UCMR 5 will provide USEPA with data on the national occurrence of the identified contaminants in drinking water systems, which will be used, along with other available information, to inform USEPA’s future regulatory efforts — including the potential establishment of federally enforceable drinking water MCLs for any of the 29 PFAS compounds identified in the rule, where the data supports the establishment of a regulatory standard.

Regulatory Determination 4: Final Determinations on PFOA and PFOS

While the UCMR 5 may signal a possibility of future regulation for 29 PFAS compounds, Regulatory Determination 4 removes lingering doubt for two of them: PFOA and PFOS.

Section 1412(b)(1)(A) of the SDWA authorizes USEPA to regulate a contaminant in drinking water if the administrator determines that:

  • the contaminant may have an adverse effect on the health of persons;
  • the contaminant is known to occur or there is substantial likelihood that the contaminant will occur in [PWSs] with a frequency and at levels of public health concern; and
  • in the sole judgment of the Administrator, regulation of such contaminant presents a meaningful opportunity for health risk reduction for persons served by [PWSs].[10]

Once USEPA determines that a contaminant meets these criteria, USEPA initiates rulemaking to establish national primary drinking water regulations, or MCLs.

The fourth iteration of the Contaminant Candidate List (CCL 4) is currently in effect. Through Regulatory Determination 4,[11] USEPA has now explicitly determined that the criteria of SDWA § 1412(b)(1)(A) have been satisfied, thereby stating its intention to establish national primary drinking water standards for two CCL 4 compounds, PFOA and PFOS, under the SDWA. As a result, USEPA will soon start the lengthy process[12] of proposing and promulgating drinking water regulations that set MCLs for these two contaminants. Pursuant to the SDWA, USEPA will have 24 months from the date of Regulatory Determination 4’s final publication to propose regulations for PFOA and PFOS, and then another 18 months to take action on final regulations. The final promulgation deadline may be extended by up to nine months.[13]

Accelerated Regulatory Consideration of Other PFAS Compounds

Perhaps as important as its decision to promulgate primary drinking water standards for PFOA and PFOS, in Regulatory Determination 4, USEPA also expressed its intention to move forward with its consideration of other PFAS compounds on an accelerated basis. Referencing the commitments made in the PFAS Action Plan and noting the progress made in developing data on PFAS compounds, USEPA states that it “will continue to prioritize regulatory determinations of additional PFAS in drinking water.”[14] Thus, while the SDWA does not require USEPA to complete regulatory determinations for contaminants on the fifth CCL until 2026, it “is committing to making regulatory determinations in advance of the next SDWA deadline for additional PFAS for which the Agency has a peer reviewed health assessment, has nationally representative occurrence data in finished drinking water, and has sufficient information to determine whether there is a meaningful opportunity for health risk reduction for persons served by [PWSs].”[15]

Finally, in addition to the sampling being conducted for the 29 PFAS compounds included in UCMR 5, USEPA specifically notes that it is in the process of developing toxicity assessments on seven PFAS compounds, including: PFBS, PFBA, PFHxS, PFHxA, PFNA, PFDA, and HFPO-DA (GenX chemicals), all of which are currently scheduled to be completed by or perhaps in 2022. These are the PFAS compounds for which we are likely to next see regulatory action at the federal level.

Implications for the Regulated Community

UCMR 5 and Regulatory Determination 4 are clear signals that federal PFAS regulation is moving forward. Although only PFOA and PFOS have received affirmative determinations for SDWA regulation, USEPA has signaled that PFAS regulation remains a priority, and we can expect to see continued focus on the assessment and regulation of PFAS compounds in the months and years ahead. For example, USEPA solicited comment on contaminants for inclusion in CCL5 in October 2018 and is expected to move forward with a proposed CCL5 in the near future. That proposal may provide some insight as to whether USEPA will continue to view PFAS compounds individually from a regulatory standpoint, or whether the USEPA may shift to a more class-based regulatory approach.[16]