In February 2009, the Washington State Department of Ecology (Ecology) issued WSDOT an NPDES permit to authorize discharges from our stormwater conveyance systems within areas covered by Phase I and Phase II Municipal Stormwater Permits. WSDOT's 2009 permit replaced and expanded WSDOT's previous NPDES coverage, which was in place since 1995. Soon after Ecology issued WSDOT's 2009 stormwater permit, it was appealed. In January 2010, Ecology, WSDOT, and the appellant reached a settlement. Ecology modified WSDOT's permit in March 2010 to implement the settlement agreement. Among other things, the settlement requires Ecology to modify WSDOT's NPDES permit or issue an administrative order at least every 18 months to establish new permit requirements related to Total Maximum Daily Loads. Ecology issued WSDOT's most recent permit modification in March 2012.
To comply with the Municipal Stormwater Permit's terms, WSDOT updated its Highway Runoff Manual (HRM) and Stormwater Management Program Plan. Both the HRM and the Stormwater Management Plan are included as appendices in the permit.
Learn more about stormwater and what WSDOT is doing to manage stormwater:
The Washington State Department of Ecology's Construction Stormwater General Permit regulates stormwater discharges from construction sites. Projects with particularly sensitive environmental concerns may be required to obtain an individual NPDES construction stormwater permit.
Washington State Department of Ecology's Industrial Stormwater General Permit regulates stormwater discharges from Washington State Ferries' Eagle Harbor Maintenance Facility.
Sand and Gravel
Washington State Department of Ecology's Sand and Gravel General Permit regulates discharge of pollutants from WSDOT's sand and gravel mining operation.