Wyoming Statewide Rule
Wyoming Stormwater Discharge Permits Under WYPDES
Key Facts
- Permit Program
- WYPDES
- Construction Trigger
- 1 acre disturbance
- Lead Agency
- Wyoming DEQ
- Required Plan
- SWPPP
- Max Penalty
- $10,000 per day
Summary
The Wyoming Department of Environmental Quality administers the Wyoming Pollutant Discharge Elimination System, which requires state permits for construction, industrial, and municipal stormwater discharges. WYPDES requirements apply statewide and supersede inconsistent local stormwater rules.
(a) No person, except when authorized by a permit issued pursuant to the provisions of this act, shall: (i) Cause, threaten or allow the discharge of any pollution or wastes into the waters of the state; (ii) Alter the physical, chemical, radiological, biological or bacteriological properties of any waters of the state;
Full Breakdown
Authorized under Wyoming Statutes 35-11-301 and the federal Clean Water Act, WYPDES governs stormwater discharges from construction sites disturbing one or more acres, designated industrial activities, and small municipal separate storm sewer systems (MS4s). Operators must file Notices of Intent, prepare Stormwater Pollution Prevention Plans (SWPPPs), and implement best management practices for sediment, erosion, and pollutant control. Small Wyoming MS4 communities such as Cheyenne, Casper, and Laramie operate under general permits with mandatory public education, illicit discharge detection, and post-construction controls. Local stormwater ordinances must align with WYPDES minimums but may be stricter.
Violations & Penalties
Violations carry civil penalties up to $10,000 per day per violation under W.S. 35-11-901, plus potential criminal liability for willful or negligent violations.
Frequently Asked Questions
Do I need a Wyoming stormwater permit for a small home build?
Who enforces stormwater rules in Wyoming?
Sources
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