Amendments made in 1987 to the Federal Clean Water Act required the U.S. Environmental Protection Agency (EPA) to develop regulations for storm water discharges from "industrial activities."

Storm water regulations were established by EPA for National Pollutant Discharge Elimination System (NPDES) permit application requirement for certain types of industrial facilities or certain types of industrial activities. EPA's storm water regulations were published in the Federal Register on November 16, 1990, March 21, 1991, November 5, 1991, April 2, 1992 and December 8, 1999. These regulations established NPDES permit application requirements for certain types of industrial facilities or certain types of industrial activities. Since 1978 , The Iowa Department of Natural Resources (IDNR) has been delegated by the EPA to administer the federal NPDES wastewater discharge permit program. In August 1992 the IDNR received authorization from EPA to issue general permits for storm water discharges. IDNR continues issuing NPDES permits to all storm water discharges subject to the federal permit requirements.


Quality of Storm Water Runoff

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

Storm water runoff from areas where industrial activities occur may contain toxics (for example, lead, zinc, etc.) and conventional pollutants such as oil and grease, fertilizers, sediment from construction sites, and other industrial site contaminants, when material management practices allow exposure to storm water. In addition, illicit connections to storm sewers may also exist and introduce contaminants through storm sewer systems. Eventually these contaminants have the potential to effect additional downstream receiving waters. Contaminants introduced in storm water runoff or into storm sewers may impact drinking water sources, waters protected for recreation, waters protected for aquatic life as well as other beneficial uses.