Susan Bodine, Partner, E&W Law
John Sheehan, Partner, E&W Law
On March 14, 2023, EPA released the pre-publication copy of its proposed Maximum Contaminant Levels (MCLs) for PFOA, PFOS, PFNA, PFHxS, PFBS, and GenX Chemicals. Comments will be due 60 days after the proposal is published in the Federal Register.
For PFOA and PFOS, EPA is proposing an MCL of 4 parts per trillion, calculated separately. These proposed MCLs, which are 1000 times higher than EPA’s Health Advisory Levels for the same chemicals, are at the limit at which PFOA and PFOS can be reliably measured. EPA also is proposing Maximum Contaminant Level Goals (MCLGs) for PFOA and PFOS of 0. MCLGs are levels at which no known or anticipated adverse health effect is expected to occur and do not consider feasibility or the limit of detection. MCLs must be set at levels that are as close to the MCLG as feasible. The inability to quantify a contaminant below a certain level is a limitation on feasibility. When promulgating an MCL, EPA also must determine that the benefits justify the costs.
For PFNA, PFHxS, PFBS, and GenX Chemicals, collectively, EPA is borrowing a tool used in the Superfund program to set cleanup levels for noncancer risks and is proposing both a MCL and a MCLG as a Hazard Index of 1. Use of the Hazard Index allows EPA to evaluate risk posed by mixtures of these chemicals. EPA plans to post a web-based tool that public water systems can use to calculate the Hazard Index.
EPA made a final regulatory determination for PFOA and PFOS in March 2021, finding that these contaminants (1) may have an adverse effect on the health of persons, (2) are known to occur or there is a substantial likelihood that the contaminant will occur in public water systems with a frequency and at levels of public health concern, and (3) regulation of such contaminant presents a meaningful opportunity for health risk reduction persons served by public water systems. For PFNA, PFHxS, PFBS, and GenX Chemicals, EPA is making a preliminary regulatory determination concurrently with the proposed MCL in the same proposed rulemaking.
Public water systems, defined in the Safe Drinking Water Act as systems with at least 15 service connections or that regularly serve at least 25 individuals, are legally required to meet MCLs. They are not required to meet MCLGs. However, section 121 of CERCLA requires remedial actions to attain MCLGs, where EPA considers the MCLG to be relevant and appropriate. As a practical matter, groundwater cleanups rarely meet MCLGs.
At a 3 percent discount rate, EPA estimates that the total annual costs will be between $705 million and $850 million. At the same rate, EPA estimates that the annual benefits will be between $660 million and $1.99 billion. Using the 3 percent discount rate, the annualized expected benefits exceed the expected costs. However, if a 7 percent discount rate is used, the annualized expected benefits are $296 million lower than the expected costs.
EPA admits that the proposed rule affects approximately 62,000 small public water systems, contains an unfunded mandate of more than $100 million a year, and is subject to both the Unfunded Mandates Reform Act and the Regulatory Flexibility Act.
Affected parties may wish to comment on EPA’s proposed regulatory determination for PFNA, PFHxS, PFBS, and GenX Chemical, on EPA’s determination that a MCL of 4 parts per trillion is feasible, on the estimated costs and benefits of the rule, and whether the benefits would exceed the costs. Earth & Water Law stands ready to assist.