Government ยป Engineering

National Pollutant Discharge Elimination System (NPDES)

National Pollutant Discharge Elimination System (NPDES)

Clay County participates in the National Pollutant Discharge Elimination System (NPDES) program to help protect local waterways and reduce stormwater pollution. The program establishes requirements for managing stormwater runoff and maintaining compliance with state and federal environmental regulations.

About the NPDES Program

In 2000, the U.S. Environmental Protection Agency (EPA) authorized the Florida Department of Environmental Protection (FDEP) to implement the National Pollutant Discharge Elimination System (NPDES) stormwater permitting program in Florida.

The program regulates point source discharges of stormwater runoff by small Municipal Separate Storm Sewer Systems (MS4s), of which Clay County is listed in the Federal Register as meeting the program requirements.

Under the NPDES stormwater program, large, medium, and regulated small MS4 operators require authorization to discharge pollutants under an NPDES permit. Medium and large MS4 operators are issued individual permits, while regulated small MS4 operators may be covered by an individual permit, a general permit, or a modification of an existing Phase I MS4 permit.

MS4 Classifications

The definition of medium and large MS4s depends on the population size in the area where the system is located:

  • Medium MS4: Population between 100,000 and 249,999.
  • Large MS4: Population of 250,000 or more.

For specific information regarding MS4 classifications and permitting requirements, please visit the FDEP website .

Why Stormwater Protection Matters

Water pollution degrades surface waters, making them unsafe for drinking, fishing, swimming, and other activities. As authorized by the Clean Water Act, the NPDES permit program helps control water pollution by regulating point sources that discharge pollutants into waters of the United States. Point sources include discrete conveyances such as pipes and man-made ditches.

Helpful Links and Resources