On April 7, 2025, EPA issued an Administrative Compliance Order to the town of Hatfield, MA for violations of the 2016 General Permit for Stormwater Discharges from Small Municipal Separate Storm Sewer Systems in Massachusetts (MS4 Permit). The Order cites its failure to develop or modify, as appropriate, a post-construction stormwater management ordinance within three (3) years of the effective date of the Permit (i.e., by July 1, 2022). The Order requires the town to enact a post-construction stormwater management ordinance or other regulatory mechanism by February 2, 2026, notify EPA that such an ordinance or regulatory mechanism has become effective within 7 days of its effective date; and provide the Agency with a copy of the regulatory mechanism. The Order will facilitate the reduction of pollutants found in the permittee's stormwater through the retention or treatment of stormwater after construction on new or redeveloped sites. The Region coordinated with the Massachusetts Department of Environmental Protection (MassDEP) on this matter.