On November 12, 2021, MassDEP promulgated amendments to the Massachusetts Surface Water Quality Standards (the "Regulation"), 314 Code of Massachusetts Regulations (CMR) 4.00. Subsequently, MassDEP published two sets of corrections, effective December 10, 2021 and January 7, 2022. An unofficial version of the Regulation, as amended and corrected, is available online. The Regulation is enforceable by the Commonwealth, but federal Water Quality Standards regulations promulgated at 40 Code of Federal Regulations Part 131, 40 CFR 131, pursuant to the federal Clean Water Act, 33 USC 1251 et seq., require that revisions to state water quality standards be approved by the U.S. Environmental Protection Agency (EPA) for the revisions to be federally enforceable for Clean Water Act purposes (including, for example, application of the Regulation for water quality assessments and National Pollutant Discharge Elimination System permits).
MassDEP published a summary of all amendments to the Regulation entitled, Summary of Final Revisions to the Massachusetts Surface Water Quality Standards (314 CMR 4.00) and Response to Comments. EPA approved the majority of revisions to the narrative portion of the Regulation, classification tables, generally applicable criteria and their associated appendices, and all revisions to site-specific criteria. EPA disapproved the removal of Public Water Supply qualifiers from seven waterbodies. In addition, EPA deferred approving or disapproving (i.e., “deferred action” on) a few amendments pertaining to new and revised criteria, surface water classifications, and qualifiers. Further details on EPA’s approvals, disapprovals, and deferred actions are available in a MassDEP summary document entitled, Status of the 2021 Amendments to the Massachusetts Surface Water Quality Standards (314 CMR 4.00).