Beginning this year, Seattle Public Utilities will commence work on the Ship Canal Water Quality Project. The project will involve construction of a tunnel from Ballard to Wallingford with the ultimate goal of preventing sewage overflows into Puget Sound. While tunneling has yet to begin, the first step of the project, in our neighborhood, was taken late last year with the installation of a temporary and hard-to-find art exhibit at the Wallingford end of the tunnel. More on that later.
Over in Ballard near 24th Ave NW and Shilshole Ave NW, some work actually began in 2018 to prepare to dig an access hole to contain, among other things, a pump station. A 2.7-mile, nearly 19-foot diameter tunnel will extend from that site to the Wallingford site. The idea is to provide a temporary holding place for some of the storm water and sewage delivered to the treatment plant in Magnolia during times of heavy rainfall. Currently, excess water and sewage that the plant cannot handle is discharged into the ship canal, Salmon Bay and Lake Union and that’s … not good. After a storm, when the load on the treatment plant has come down to normal levels, water and sewage from the tunnel will be pumped out of the tunnel and onward to the treatment plant. The tunnel system will receive water and sewerage from Queen Anne, Fremont, Ballard and Wallingford, so the impact will be widespread. According to the SPU website, in 2018 84% of the overflows came from these neighborhoods as well as Capitol Hill and downtown, so construction of this tunnel will obviously take a big bite (a big gulp?) out of those overflows.
The major project elements in our neighborhood are:
- A new 60-ft deep, 30-ft diameter vertical shaft near Stone Way N and N 35th St to convey stormwater and sewage into the tunnel
- New pipe installation along Stone Way N and N 35th St to connect the current sewer system to the new vertical shaft
- A new small, above-ground maintenance and odor control building near 3500 Interlake Ave N
In terms of timeline, here’s what to expect:
- Shaft construction (Begin early to mid-2021)
- Site remediation (Begin early to mid-2021)
- New pipe installation (Begin early 2022)
- Permanent art installation (Late 2022)
The project will not wrap up until 2023 at the earliest. Many more details can be found here.
And now, about that art …
I had read about the temporary art that was supposed to go in at the Wallingford site in late 2019. The piece was to be created by Ryan! Feddersen who is creating a number of works along the route of the tunnel (see map below). I looked each time I passed by the Wallingford site, and I couldn’t see anything. Finally, I emailed Kelsey Hinsperger at SPU who told me that the trick is in where — and when — you look. Wrote Hinsperger:
Thanks for checking in! The temporary art pieces are in at Wallingford, but there’s a trick to finding them. They’re only visible while it’s raining! The artist, Ryan! Feddersen, used a rain-activated coating to paint medallions on the sidewalks.
So when I was looking during our unusually dry November and December, my timing may have been off. And anticipating something like a statue, I was probably not looking down. Now that it’s pouring almost every day and you know to look more towards your shoes than the horizon, you’ll have no trouble spotting these new creations.
Nearby residents will be interested in the matter of air flow in the tunnel. The way I remember it, early SPU presentations had active air flow – fans or something – west towards the Ballard tunnel exit, but a later presentation left the impression there might not be any, and it would be up to the “maintenance and odor control building” to deal with that.