New Sewage Control Project Along Ship Canal

The Public Utilities and Neighborhoods Committee today approved a project that will reduce the overflow of sewage into the Ship Canal.Earlier this year, the Council approved a plan to improve water quality throughout Seattle’s waterways as required by a 2012 Consent Decree with the U.S. government over violations of the Clean Water Act (Seattle Times coverage). This project — officially the Ship Canal Water Quality Project — is one outcome of that effort. It builds storage and containment facilities along the canal in Wallingford, Fremont, Ballard and north Queen Anne.  It’s a joint project of King County and Seattle (since they both currently have sewage outflows that dump into the Ship Canal), with shared work, cost sharing, oversight and maintenance.

The problem is that the sewer system handles both  sewage and stormwater, and has “combined outflows” that handle overflow during large storms  when the volume exceeds the capacity of the West Point sewage treatment plant; unfortunately those outflows dump into the Ship Canal. The new system will provide additional storage and containment capacity so as to significantly reduce the number of instances of outflow into the canal.

Here is the presentation they used today, with project details and budget.

This spring they will develop the Environmental Impact Statement; they will then spend 18 months on design. They hope to start construction in the beginning of 2018 and finish in 2024. The entire project will cost $423 million — plus up to 30% or minus up to 20%.

Committee chair Bagshaw amended the project approval to require SPU to report back to the Council every six months over the course of the project. The committee referred it to the full Council for its approval next week.