SW

Stormwater Directory

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Compare state-level permit requirements side-by-side (up to 4 states)

WA(3 more)

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Field
WA
Washington
NPDES ProgramState-Delegated
Permitting AgencyWashington State Department of Ecology (Ecology)
Permit NameConstruction Stormwater General Permit (CSGP)
Construction Threshold≥ 1 acre of land disturbance (or < 1 acre if part of a larger common plan)
NOI Lead TimeNOI must be submitted and permit coverage confirmed before any land-disturbing activities begin. Ecology targets a 38-day review period.
Application MethodOnline via Ecology's Permit and Reporting Information System (PARIS)
Permit FeeAnnual fee ranging from $800 (< 1 acre) to $4,800 (≥ 100 acres)
SWPPP RequiredYes
PE Certification RequiredNo
SWPPP Template AvailableYes
Inspection FrequencyEvery 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.
Inspector QualificationCertified Erosion and Sediment Control Lead (CESCL) — state-mandated certification through Ecology-approved training program. Renewal required every 3 years.
Post-Construction RequiredYes
Turbidity StandardDischarges 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.