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Stormwater Program

 


General Information

Years after the Clean Water Act of 1972 was adopted, EPA completed rules to include stormwater discharges in the NPDES permit program. Since Iowa was delegated the NPDES program for wastewater discharges, delegation was requested for stormwater discharges as well. Information regarding the stormwater permit program and how it is managed by the Iowa DNR can be found in the following pages:

  • State Revolving Fund - Offers low-interest loans for stormwater practices that protect water quality. Eligible borrowers include both public and private entities.

Contact Information


History of Stormwater NPDES Permitting Requirements

Amendments made in 1987 to the Federal Clean Water Act required the U.S. Environmental Protection Agency (EPA) to develop regulations for stormwater discharges from "industrial activities." Stormwater regulations were established by EPA under the National Pollutant Discharge Elimination System (NPDES) permit requirements for certain types of industrial facilities and industrial activities. EPA's stormwater regulations were published in the Federal Register on the following dates:

  • November 16, 1990,
  • March 21, 1991,
  • November 5, 1991,
  • April 2, 1992, and
  • December 8, 1999. 

These federal regulations established NPDES permit application requirements for industrial facilities and industrial activities. Since 1978, the Iowa Department of Natural Resources (DNR) has been delegated by the EPA to administer the federal NPDES wastewater discharge permit program. In August 1992, the DNR received authorization from EPA to issue general permits for stormwater discharges. The DNR continues to issue NPDES permits to all stormwater discharges subject to the federal NPDES permit requirements.


Quality of Stormwater Runoff

The intent of the federal stormwater regulations is to improve water quality by reducing or eliminating contaminants in stormwater. Stormwater is defined as precipitation runoff, surface runoff and drainage, street runoff, and snow melt runoff.

Stormwater runoff from areas where industrial activities occur may contain the following contaminants:

  • toxic substances (lead, zinc, etc.),
  • conventional pollutants (oil and grease, fertilizers, sediment from construction sites), or
  • industrial site contaminants, when material management practices allow exposure to stormwater.

In addition, illicit connections to storm sewers may also exist and can introduce contaminants through storm sewer systems. Contaminants introduced in stormwater runoff or into storm sewers may impact drinking water sources, waters protected for recreation or aquatic life, and other beneficial water uses.