Westchester County, NY Environmental Rules: Stormwater Management (2026)
Key Facts
- Governing section
- § 823.05, Laws of Westchester County
- Enforcing agency
- Dept. of Public Works and Transportation
- Civil penalty
- $250 to $1,000 per violation
- Criminal penalty
- Up to $1,000 or 6 months jail
Summary
Westchester County bans any non-stormwater discharge into its municipal separate storm sewer system countywide, with narrow exemptions for things like pool backwash and residential car-washing runoff.
No person shall discharge or cause to be discharged into the County's MS4 any materials other than stormwater. The commencement, conduct or continuance of any illicit discharge to the MS4 is prohibited, except as described in subsection 2 of this section. A discharge can be direct through a pipe, or indirect via overland surface flow.
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: Code of Ordinances: Supplement 47).
Full Breakdown
Laws of Westchester County § 823.05 prohibits discharging anything but stormwater into the County's MS4, whether the discharge comes through a pipe or as overland surface flow, and the ban applies wherever the County's storm sewer system runs, not just unincorporated areas. The chapter carves out a list of exempt discharges, water line flushing, landscape irrigation, residential car washing, dechlorinated pool water, firefighting water, and similar sources, unless the Commissioner later finds them a substantial pollutant contributor. SPDES-permitted discharges and Commissioner-approved emergency discharges are also allowed.
Violations & Fines
Violations bring a notice of violation, a civil penalty of $250 to $1,000, and criminal fines up to $1,000 or six months in jail for repeat offenses under § 823.14.
Frequently Asked Questions
Can I wash my car and let the water run into the street?
Does the county's stormwater ban apply inside cities like Yonkers?
Sources & Official References
Other rules in Westchester County
New York rules heatmap·Compare Westchester County to another location·View the New York environmental rules overview
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