NPDES MS4 Phase II Report
Stormwater regulations adopted by the Environmental Protection Agency (EPA) in November 1990 led to the issuance in 1993 of a National Pollutant Discharge Elimination System (NPDES) Municipal Separate Storm Sewer System (MS4) Discharge Permit to Prince George's County, Maryland. This permit is administered by the Maryland Department of the Environment.
County Permit
According to 40 Code of Federal Regulations (CFR) §122.26, owners of storm sewer systems serving populations greater than 100,000 were required to apply for Phase I NPDES MS4 permit coverage. The County permit has been renewed 3 times, in 1999, 2004, and 2014. The latest permit renewal outlined more stringent requirements than those imposed in previous permit renewals.
Permit Conditions
Previous permit conditions mandated the County to:
- Develop a geographic information system map at the watershed scale.
- Develop management programs to address new and significant redevelopment runoff, construction site discharges, illegal storm drain system connections, and road maintenance operations.
- Maintain legal authority to control stormwater pollution in the storm drain system.
- Provide education and outreach regarding stormwater pollution.
- Use a combination of chemical, physical, and biological monitoring to characterize urban stormwater.
The new permit increased the impervious area treatment goals from 10% to 20% of the total impervious area regulated by the County. Additionally, the 2014 permit augmented the permit conditions to include:
- Litter and trash reduction strategies.
- Implement environmental site design (ESD) technologies for new and redevelopment projects to the maximum extent practicable (MEP).
- Development of watershed restoration plans to address stormwater waste load allocations (WLA) established under the EPA-approved total maximum daily loads (TMDL) estimates.
The overall goals of the County's five-year NPDES municipal stormwater permit program are to control stormwater pollutant discharges by implementing Best Management Practices (BMP) and programs, show a reduction of pollutants pursuant to EPA-approved TMDLs, and improve water quality. The County annually evaluates and documents progress toward improving water quality within its jurisdiction and submits a report to MDE. Please look at the links below to see this report and other reports the County has developed.
You can access the latest NPDES MS4 annual report documentation submitted to MDE below.
Access the Watershed Restoration Plans and supporting documents, developed to outline the County's strategy to improve water quality. Please note that you will be taken to an external site that is not managed by the County.