EPA controls stormwater overflow discharges
through its National Pollutant Discharge Elimination System (NPDES). In
1990, the EPA issued the Stormwater NPDES Phase I Regulations as required
by the Clean Water Act. The Phase I regulations cover urban areas with
a population of 100,000 or more.
As authorized by the Clean Water Act, the National Pollutant Discharge
Elimination System (NPDES) permit program controls water pollution by
regulating point sources that discharge pollutants into waters of the
United States. Point sources are the outfalls from conveyances such as
pipes or man-made ditches. In most cases, the NPDES permit program is
administered by authorized states. Since its introduction in 1972, the
NPDES permit program is responsible for significant improvements to our
nation's water quality.