Norwalk, CT Environmental Rules: Stormwater Management (2026)

Chapter 93, Stormwater, Illicit Discharges and Connections, adopted May 25, 2010, implements Norwalk's National Pollutant Discharge Elimination System (NPDES) municipal separate storm sewer system (MS4) permit. Section 93-7A bars discharging any pollutant other than storm water into the municipal storm drain system, wetlands or watercourses, with narrow listed exceptions such as uncontaminated water-line flushing, landscape irrigation, diverted stream flows, groundwater infiltration, air-conditioning condensation and noncommercial vehicle washing. Section 93-7B separately prohibits building, using or maintaining any illicit connection to the storm drain system, including past connections regardless of whether they were legal when made, and treats a sewage line tied into the MS4 as a per se violation.

The Director of Public Works administers the chapter (Section 93-4) and can, without prior notice, suspend a property's access to the MS4 in an emergency threatening the environment or public health (Section 93-8A), or terminate access after finding an ongoing illicit discharge (Section 93-8B). Inspectors may enter and sample regulated facilities as often as needed to check compliance, and unreasonable delay in granting that access is itself a violation of both the chapter and any NPDES permit (Section 93-10). Anyone who spills or suspects a release of pollution-causing material must notify emergency responders immediately for hazardous materials, or the Director by the next business day for nonhazardous releases, and keep a written on-site record for at least three years if the discharge came from a commercial or industrial site (Section 93-13).