March 30, 2023
Bryan P. Franey, Esq. and Jessica D. Hunt, Esq.
MGKF Special Alert
Updated March 30, 2023 with posted hearing dates
In mid-March EPA proposed regulations to establish new maximum contaminant levels (MCLs) and new and revised maximum contaminant level goals (MCLGs) for six PFAS compounds: perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS), perfluorohexane sulfonic acid (PFHxS), hexafluoropropylene oxide dimer acid (HFPO-DA) and its ammonium salts (commonly known as GenX chemicals), perfluorononanoic acid (PFNA), and perfluorobutane sulfonic acid (PFBS). An MCL is an enforceable standard, defined as the maximum level allowed of a contaminant or mixture of contaminants in water that is delivered to any use of a public water system. In contrast, an MCLG is a non-enforceable public health goal, defined as the maximum level of a contaminant in drinking water at which no known or anticipated adverse effect on the health of persons would occur, allowing an adequate margin of safety.
The proposed MCLs and MCLGs are as follows:
|Compound||Proposed MCLG||Proposed MCL|
|PFOA||Zero||4.0 parts per trillion (ppt)|
|PFNAPFHxSPFHxSHFPO-DA and its ammonium saltPFBS||Hazard Index 1.0 (unitless)*||Hazard Index 1.0 (unitless)*|
* The total sum of each PFAS hazard quotient (determined by dividing the measured level of each of the four PFAS in drinking water by a health reference value for each PFAS).
The proposed regulations would require public water systems that detect PFAS above the MCLs to install treatment technology and would impose additional monitoring, recordkeeping and reporting requirements. Once finalized, the MCLs would become the national limits on PFOS and PFOA in drinking water, replacing the individual MCLs promulgated by states.
EPA is accepting written comments on the proposed regulations. Written comments must be submitted to EPA on or before May 30, 2023. EPA will also be holding a virtual public hearing on May 4, 2023 from 11 AM to 7 PM. To attend the public hearing, you must register by May 2, 2023 on EPA’s website. The last day to register to speak at the hearing will be April 28, 2023.