Bridge & Ferry Terminal Washing Permit

Due in part to the May 23, 2013, collapse of the Skagit River Bridge, the Washington State Department of Transportation (WSDOT) and local governments developed a robust schedule to inspect and repair bridges and ferry terminals statewide. Bridges must be washed prior to inspection to help detect cracks and other problems.

To make this important work easier for governments, we developed a National Pollutant Discharge Elimination System (NPDES) and State Waste Discharge general permit to set guidelines for bridge and ferry terminal washing across the state. The permit serves to protect water quality while supporting inspection and maintenance of bridges — and protecting the safety of Washington commuters.

The Bridge and Ferry Terminal Washing general permit was issued June 29, 2022, and has an effective date of Aug. 1, 2022. This permit will remain effective until July 31, 2027.

Current permit documents

Monitoring guidance documents

Permit reissuance

The current permit expires July 31, 2027. We are starting the reissuance process one year early to address the wastewater discharge from bridge platform hydro-demolition activities.

The permit reissuance process includes collaboration with subject matter experts, working with current permittees and interested parties, and a formal public comment period on the draft permit with informational presentations and public hearings. We plan to make a permit reissuance decision in Spring 2026.

Anticipated timeline

Winter 2025: Formal public comment period on the draft permit
Early 2026: Informational presentations and public hearings
Spring 2026: Decision on reissuance

Historical permit documents

2017 general permit (June 21, 2017 - July 31, 2022)