Storm Water Phase I
In 1987, Congress amended the Clean Water Act (CWA) to require implementation, in two phases, of a comprehensive national program for addressing storm water discharges. The first phase of the program, commonly referred to as "Phase I" was promulgated on November 16, 1990, (55 FR 47990). Phase I in 40 CFR Parts 9, 122, 123, and 124 requires National Pollutant Discharge Elimination System (NPDES) permits for storm water discharge from a large number of priority sources. These sources include municipal separate storm sewer systems (MS4s) generally serving populations of 100,000 or more and several categories of industrial activity, including construction sites that disturb five or more acres of land. The SDDOT was issued a joint Phase I permit with the City of Sioux Falls effective November 1, 1999. The permit expiration is September 30, 2004.
Storm Water Phase I MS4s