Massachusetts

Massachusetts was one of the first states to adopt an enforceable drinking water MCL for PFAS. In 2020 the Massachusetts Department of Environmental Protection finalized a state MCL of 20 parts per trillion for the sum of six PFAS compounds, including PFOA, PFOS, PFHxS, PFNA, PFHpA, and PFDA. This is a stricter combined threshold than the federal EPA individual MCLs finalized in April 2024, though the federal rule regulates each compound separately.

The MassDEP required all public water systems in the state to begin sampling for these six compounds on a defined schedule, and utilities that exceeded the 20 parts per trillion threshold were required to notify customers and begin treatment or alternate supply planning. The state has published ongoing results publicly.

The Massachusetts legislature has appropriated funding for PFAS treatment grants through the state Clean Water Trust. State records show MassDEP has focused enforcement attention on contamination near Joint Base Cape Cod and the former Westover Air Reserve Base, both of which have extensive AFFF firefighting foam plumes.

Public water systems in Massachusetts are subject to both the state PFAS6 standard and the federal compliance timeline requiring initial monitoring by 2027 and treatment installation by 2029.