Suffolk County, NY Environmental Rules: Stormwater Management (2026)

The USEPA and New York State Department of Environmental Conservation (NYSDEC) are increasing their attention in several ways. There are three State Pollutant Discharge Elimination System (SPDES) general permits required for activities associated stormwater discharges. The Multi-Sector General Permit for Stormwater Discharges Associated with Industrial Activities (MSGP) addresses stormwater runoff from certain industrial activities. This permit requires facilities to develop stormwater pollution prevention prevention plans (SWPPPs) and report the results of industry-specific monitoring to the NYSDEC on an annual basis. A federal regulation, commonly known as Stormwater Phase II, requires the General Permit for Stormwater Discharges from Municipal Separate Storm Sewer Systems (MS4 GP). MS4 Operators are required to develop a stormwater management program (SWMP) to reduce the discharge of pollutants to the maximum extent practicable. Construction activities disturbing one or more acres of soil must be authorized under the General Permit for Stormwater Discharges from Construction Activities (CGP). Permittees are required to develop a SWPPP to prevent discharges of construction-related pollutants to surface waters.