The Environmental Protection Agency announced March 14 that it is proposing maximum contaminant levels for PFAS in public water supplies. The agency expects the final version of the proposal to be adopted by the end of 2023.
PFAS is an abbreviation for perfluoroalkyl and polyfluoroalkyl substances, a family of over 9,000 compounds. Many of these substances do not degrade over time, earning them the nickname “forever chemicals.” They are used to make stain-resistant, water-resistant, and nonstick products. According to the Centers for Disease Control and Prevention, most people in the U.S. have PFAS in their blood, especially the two compounds PFOA and PFOS. The substances enter the bloodstream from contact with products or ingesting food or water that contains them.
The EPA’s proposed maximum levels differ from the maximum contaminant level defined by the state. The Massachusetts DEP drinking water regulation considers the sum of six specific PFAS compounds to be acceptable if it is less than 20 parts per trillion in a public drinking water supply. The EPA proposal sets a maximum of four parts per trillion on each of two compounds: PFOA and PFOS. It also includes a maximum “hazard index” for the sum of four other compounds.
The EPA is also proposing a non-enforceable maximum contaminant level goal of zero parts per trillion for both PFOA and PFOS. In a pre-publication version of the proposed regulation, the EPA made the following statement: “Following a systematic review of available human epidemiological and animal toxicity studies, EPA has determined that PFOA and PFOS are likely to cause cancer (e.g., kidney and liver cancer) and that there is no dose below which either chemical is considered safe.” But current testing cannot detect very low levels of PFOA and PFOS, so the agency set the maximum level to the lowest number testing could accurately achieve.
The four other compounds in the EPA proposal would be weighed together. The agency stated that, unlike PFOA and PFOS, low levels of those four substances would “not likely result in adverse health effects,” but as a mixture, they would. One of those substances, HFPO-DA, commonly known as GenX chemicals, was manufactured in 2009 to replace PFOA when it was found to be carcinogenic.
The state does not currently regulate two of the substances in the EPA’s proposal, GenX chemicals and PFBS, and it does not have individual limits on PFOA or PFOS. When the regulation is finalized, Massachusetts will be required to modify its maximum contaminant level for PFAS in public water supplies to be at least as strict as the new EPA standards.
What does it mean for Harvard?
Test results on Harvard’s public drinking water in 2020 showed only the sum of the state regulation’s six substances, so it is unclear whether Harvard’s water would violate the EPA proposal for PFOA or PFOS levels. The levels that year varied from 6.6 ppt to 15.2 ppt. The water was tested for PFBS, and none was detected, but it was not tested for GenX chemicals.
In 2020, the Army tested 125 private wells in northwest Harvard as part of its PFAS investigations on the former Fort Devens. PFAS were found in 73 of them, and 18 tested over the state’s maximum contaminant level of 20 parts per trillion for the sum of six substances. PFOA and PFOS accounted for most of the PFAS in those wells.
At Special Town Meeting in February, the town voted to borrow $4.85 million to connect to the Devens water supply, mainly to benefit from the PFAS treatment that Devens is already providing. Whether Devens’ treatment plants would reduce PFAS levels to those proposed by the EPA is unclear.
When the EPA’s proposal is adopted, public water supplies will be required to monitor for the named PFAS substances. Should any levels be exceeded, the public would need to be notified and treatment would be required to reduce those levels to the acceptable range. No action is needed until the regulation is finalized, and public water supplies will be given time to comply. The regulation would not apply to private wells.
Written comments on the proposal are now being accepted. A public hearing, with an opportunity for public comment, will be held online May 4. For more information, go to epa.gov/sdwa/and-polyfluoroalkyl-substances-pfas.
