EPA Expected to Finalize PFAS Maximum Contaminant Levels

January 18, 2024
Bryan P. Franey, Esq.
MGKF Special Alert - 2024 Federal Forecast

In early 2024, EPA is expected to finalize 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).  EPA had originally targeted the end of 2023 as the finalization date.     

As we noted in a March 2023 Client Alert, 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


4.0 parts per trillion (ppt)
PFOS Zero 4.0 ppt



HFPO-DA and its ammonium salt



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 for the six PFAS in drinking water, replacing the individual MCLs promulgated by state (unless the state has established more stringent standards). 

Please contact MGKF’s Bryan Franey if you have questions about the new MCLs at bfraney@mankogold.com or 484-430-2308.