Connecticut Stormwater MS4 General Permit Standards

Under Conn. Gen. Stat. Sec. 22a-430 and the Clean Water Act, DEEP administers the MS4 general permit governing municipal stormwater systems. Cities and towns must enforce illicit discharge detection and elimination, public education, post-construction stormwater management, and good housekeeping practices. The 2004 Connecticut Stormwater Quality Manual and 2002 Erosion and Sediment Control Guidelines establish baseline design standards. Construction sites disturbing one or more acres require a separate Construction General Permit. Municipal ordinances must meet or exceed state minimums but cannot weaken them.

Unpermitted discharges may incur civil penalties up to $25,000 per day under Sec. 22a-438. DEEP can issue cease-and-desist orders and require remediation of contaminated runoff.