Compare Regulations
Compare state-level permit requirements side-by-side (up to 4 states)
WA(3 more)
Rows with an amber indicator differ across selected states.
| Field | WA Washington |
|---|---|
| NPDES Program | State-Delegated |
| Permitting Agency | Washington State Department of Ecology (Ecology) |
| Permit Name | Construction Stormwater General Permit (CSGP) — effective January 1, 2026 through December 31, 2030 |
| Construction Threshold | ≥ 1 acre of land disturbance (or < 1 acre if part of a larger common plan) |
| NOI Lead Time | NOI must be submitted at least 60 days before any land-disturbing activities begin (increased from prior ~38-day target under the 2021 permit). Permit coverage must be confirmed before breaking ground. |
| Application Method | Online via Ecology's Permit and Reporting Information System (PARIS) |
| Permit Fee | Annual fee ranging from $800 (< 1 acre) to $4,800 (≥ 100 acres) |
| SWPPP Required | Yes |
| PE Certification Required | No |
| SWPPP Template Available | Yes |
| Inspection Frequency | Every 7 days and within 24 hours of a storm event producing ≥ 0.5 inches of rainfall in a 24-hour period. Turbidity monitoring required at the discharge point. Under the 2026 CSGP, sites ≤ 1 acre must also conduct weekly turbidity/transparency and pH sampling at the discharge point. |
| Rain Inspection Trigger | Within 24 hours of any storm event producing ≥ 0.5 inches of rainfall in a 24-hour period; turbidity monitoring required at all discharge points after each event |
| Inspector Qualification | Certified Erosion and Sediment Control Lead (CESCL) required for ALL site inspections under the 2026 CSGP — including sites ≤ 1 acre (previously non-certified personnel could inspect smaller sites). CESCL certification through Ecology-approved training; renewal required every 3 years. |
| Inspector Certifications | Certified Erosion and Sediment Control Lead (CESCL) REQUIRED for ALL sites including ≤ 1 acre under the 2026 CSGP; Ecology-approved training provider required; renewal every 3 years |
| Post-Construction Required | Yes |
| Turbidity Standard | Discharges must not cause receiving water turbidity to exceed 5 NTU above background for fresh waters with naturally clear water; 10 NTU above background in other fresh waters. Numeric effluent limits apply: 25 NTU in some cases. |