About the NPDES MS4 Permit:
In 1972, the United States Environmental Protection Agency first administered the Clean Water Act to protect and restore the chemical, physical, and biological integrity of the Nation’s water resources. Regulating point and nonpoint source pollution, the Act is the foundation by which Federal and state agencies manage water resources. In November 1990, the U.S. EPA issued final regulations requiring National Pollutant Discharge Elimination System Permits (NPDES) for stormwater discharges from municipal separate storm sewer systems and industrial activities. The Maryland Department of the Environment administers this Federal requirement, and Anne Arundel County was among the first of Maryland’s jurisdictions to receive a Phase I NPDES Municipal Separate Storm Sewer System (MS4) permit (issued in 1993).
Within Anne Arundel County, the Department of Public Works is the lead department tasked with ensuring compliance with permit conditions. Permit compliance requires the cooperation of multiple County agencies. These agencies have primary responsibility for successfully implementing the various permit requirements. The Ecological Assessment Program has overall responsibility for administering this permit, interfacing with Federal and State regulators regarding permit compliance, coordinating activities among the responsible County agencies, and reporting permit compliance to MDE on an annual basis.
- Current Fifth-Generation NPDES MS4 Permit (issued November 5, 2021)
- County MS4 Jurisdiction Map
- County MS4 Impervious Map