On June 21, 2024, EPA issued a Clean Water Act Administrative Compliance Order to the Town of Chatham, Massachusetts for a violation of the 2016 General Permit for Stormwater Discharges from Small Municipal Separate Storm Sewer Systems in Massachusetts (2016 MS4 Permit). The Order cites the Town's alleged failure to develop or modify, as appropriate, a post-construction stormwater management ordinance within three 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 December 15, 2024, notify EPA that such an ordinance or regulatory mechanism has become effective within seven days of its effective date, and provide EPA 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. EPA coordinated with the Massachusetts Department of Environmental Protection on this matter.