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Separate Storm Sewer System MS4 Permit

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In 1972, Congress passed the Clean Water Act (CWA), which regulates discharges to waters of the United States and created a program called the National Pollutant Discharge Elimination System (NPDES). NPDES requires certain industries, municipalities, and commercial facilities to meet national water quality criteria for point source discharges to rivers and streams in the United States.

EPA Permitting Process

To discharge stormwater from the municipal separate storm sewer system (MS4), the District is required to obtain an NPDES discharge permit from the Environmental Protection Agency. NPDES permits have site-specific requirements regarding the release of discharge into waters of the US, and often include regulatory guidance for discharges from industrial and construction sites, monitoring of these discharges, enforcement activities for violators, fiscal availability of monies, and annual reporting and implementation planning.

District of Columbia MS4 Permit

The District applied for its first MS4 permit in 1999 and has been on a 5-year permit cycle since. The current MS4 permit became effective on June 22, 2018, and expires on June 22, 2023.  This permit requires the District to conduct a variety of pollution-reduction activities including implementation of stormwater best management practices (BMPs), conducting public education and outreach, and monitoring District waters for various pollutants. DOEE’s MS4 Annual Report and StoryMap provide information on the District’s accomplishments toward the permit requirements.

EPA issued an Administrative Order on Consent (AOC), effective on July 3, 2018, to resolve alleged violations of the MS4 permit. One of the requirements of the AOC was to implement an operations and maintenance (O&M) program for municipal facilities in the MS4 permit area and submit an annual report summarizing accomplishments during that year. View the annual O&M reports.

2022 MS4 Permit Reapplication

In anticipation of the current permit’s upcoming expiration, DOEE has updated two documents that consist of the next permit’s reapplication The 2022 Stormwater Management Plan (SWMP) (outlines the District’s strategy for implementing a sustainable approach to managing stormwater runoff. The plan contains details of the District’s current practices as of December 2020. The 2022 Consolidated Total Maximum Daily Load Implementation plan  updates the previous 2016 version and includes strategies and a proposed timeline for reducing pollutant loads to District waterways so that they meet all water quality standards.

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