The Virginia Department of Environmental Quality (DEQ) issues permits for the discharge of stormwater into waterways like Four Mile Run and the Potomac River. These permits, called municipal separate storm sewer system (MS4) permits, are good for five years. Arlington’s current MS4 permit (VPDES Permit No. VA 0088579) was issued on July 1, 2021.
Arlington was the first municipality in Virginia to receive an MS4 permit that includes quantitative pollution reduction requirements to clean up the Chesapeake Bay. The Chesapeake Bay Total Maximum Daily Load (TMDL), which is commonly referred to as the “bay pollution diet,” requires significant reductions in nutrient and sediment pollution across the bay watershed.
Each MS4 permit is good for five years, and the new permit will be in effect through 2026. During this permit cycle, Arlington is required to achieve a 35 reduction of its share of these bay TDML pollutants. In the last permit cycle, Arlington will be required to decrease its share of these bay TDML pollutants by an additional 60 percent (2026-2031 permit cycle).
The following programs and projects support the County’s MS4 Program:
- Ballston Pond Retrofit Project
- Volunteer Stream Monitoring Program
- Stream pollution response
- Green streets projects
- Storm and sanitary sewer rehabilitation and upgrades
- Stream resilience projects
- Street Sweeping Program
- Stormwater Master Plan
- Tree planting Programs
- Watershed retrofit studies
More information is available on the Stormwater Management page.