01 October 2020

Massachusetts Finalizes New PFAS Drinking Water Standards and Water Systems Testing Schedules

The Massachusetts Department of Environmental Protection (“MassDEP”) has finalized its enforceable Maximum Contaminant Level (“MCL”) drinking water standards for a group of six per- and polyfluoroalkyl substances (“PFAS”) after proposing similar regulatory provisions in December 2019. Under the new regulations, the MCL is set at 20 nanograms per liter (i.e., 20 parts per trillion) for the sum of the concentrations of these six distinct PFAS contaminants:  perfluorooctane sulfonic acid (“PFOS”); perfluorooctanoic acid (“PFOA”); perfluorohexane sulfonic acid (“PFHxS”); perfluorononanoic acid (“PFNA”); perfluoroheptanoic acid (“PFHpA”); and perfluorodecanoic acid (“PFDA”). No later than December 31, 2023, and every three years thereafter, MassDEP will review the science and state of PFAS analytical/treatment methodologies to determine whether these drinking water standards should be amended.