Calculating the Annual Rate of PFAS Release to Maine's Navigable Waters, Not Reported in EPA Toxics Release Inventory (TRI ) Reporting

Abstract

In 2021, the Maine Legislature passed a law that required all facilities licensed to discharge wastewater to the navigable waters of the State of Maine to sample their effluent discharge for Polyfluoroalkyl and Perfluoroalkyl substances (PFAS) and report sample data to the Maine Department of Environmental Protection (DEP).  This report uses the resulting data of flows and PFAS concentrations to determine the annual rate of PFAS discharge to Maine’s Navigable Waters.  None of the PFAS measured in this State evaluation was reported in EPA Toxics Release Inventory (TRI) reporting, presumably because it was not required to be reported as part of TRI.  However, the rate of PFAS release to Maine’s navigable waters (Maine’s fresh water and tidal water environment) is significant in magnitude.  Included are examples to show the magnitude of the discharge rate, and recommendations for ongoing monitoring and management of PFAS wastewater effluent discharge into Navigable Waters of Maine and all US states. This report does not include wastewater effluent discharged to subsurface waters via spray irrigation or subsurface disposal.