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 in order for cracks and other problems to be detected.

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 on 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

Public process

We invited comments on the draft general permit documents beginning Feb. 16, 2022, until April 1, 2022. We also held an online workshop and public hearing. During the workshop in March, we explained the proposed changes to the permit and answered questions. The hearing began immediately following the public workshop.

Bridge and Ferry Terminal Washing workshop presentation

Historical permit documents