Ship Canal Water Quality Project update 09/08/22

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Digging up Seattle’s historic and industrial past

A historic 750-gallon underground storage tank

This photo shows a historic 750-gallon underground storage tank of unknown age that was removed from the Wallingford Shaft near Interlake Ave N & N 35th St.


Sometimes when we start digging in the ground, we find things other than dirt and rocks. Luckily, we hire archeologists any time we excavate for capital projects so we can respond appropriately when we find historically significant or culturally sensitive materials. On this project, we’re digging at five sites across North Seattle, so it was only a matter of time before we ran into a few relics of the past. No buried treasure, just old industrial equipment. Recently, we unearthed an empty 750-gallon, fuel storage tank 10 feet underground from the Wallingford shaft. Our team worked with experts to decommission, remove, clean, and recycle the tank. Soils with any suspected contamination were removed and transported to a landfill in Arlington, Oregon.

Wallingford isn’t the only place where we found old industrial waste. At our East Ballard jobsite, at NW 45th St and 11th Ave NW, we excavated and disposed of diesel contaminated soil. But we found more than just yucky soil. During the excavation, we found evidence of a 100-year-old trestle bridge with steel cables and timbers buried beneath the neighborhood. Through this construction project, we got to leave the ground a little cleaner and discover some historic transportation infrastructure.

To learn more about the project, visit our project website. We also continue to update our Flickr albums with recent construction photos.


MudHoney, our 18-ft diameter tunnel boring machine, is paused for maintenance after reaching East Ballard this month. Tunneling is scheduled to resume next week. Follow along with our tunneling tracker on our project website.

Ground monitoring is ongoing along the tunnel alignment and is done from both inside MudHoney and on the surface.

MudHoney graphic


Our Ballard shaft site near Shilshole Ave NW continues to be busy with tunneling activities, including delivering new cutterhead tools for MudHoney and carrying out maintenance on the support equipment before tunneling resumes.

During regular tunneling activities, you should anticipate:

  • Truck deliveries of concrete segments and MudHoney equipment
  • Nighttime segment deliveries and tunnel spoils being hauled off
  • Noise and vibrations typical of a construction site

Crews are working 24 hours a day, six days a week and will continue until MudHoney reaches Wallingford in 2023. Sunday work may also occur. The Ballard shaft site is also the site of the future pump station.

East Ballard

Crews continue building the mechanical and electrical vault in NW 45th St and the diversion structure on 11th Ave NW. For approximately the next 2 weeks, 11th Ave NW adjacent to our work area and south of NW 45th St will be completely closed starting today. This closure is necessary for the excavation work. We have coordinated with the Fred Meyer store and vehicle access to businesses south of NW 45th St will need to go through the parking lot. When this work is done the road will revert back to the normal one-lane closure described below.

Local closures and detours:

  • One-lane closure on 11th Ave NW through November 2022. Traffic signals direct northbound and southbound traffic on 11th Ave NW and eastbound traffic on NW 45th St as well as bicyclists and pedestrian trail users. During working hours, flaggers will assist with construction vehicles entering and exiting the site. Directional signage is also in place. For safety, bicyclists should either dismount or cross train tracks at a 90-degree angle. Please use extra caution in wet weather as ramps may be slippery.
  • NW 45th St remains closed to traffic between 11th Ave NW and 9th Ave NW; vehicles must detour onto NW 46th St
  • Burke-Gilman Trail detour to the north side of NW 45th St through the project area

You should anticipate:

  • Heavy equipment in the area
  • Noise and vibrations typical of a construction site

Regular work hours will be Monday through Friday, from 7 am to 5 pm. Night and weekend work may occur.


Crews are working on the diversion structure on 2nd Ave NW. Preparations also continue for resuming conveyance tunneling beneath the Ship Canal to our Queen Anne site.

Local closures and detours:

  • 2nd Ave NW, between Leary Way NW and NW Canal St, closed to vehicle and pedestrian traffic through the end of 2022. NW Canal St is open to two-way traffic to allow access during this closure.
  • NW 36th St, between Leary Way NW and 3rd Ave NW, closed through the remainder of the project
  • Pedestrian detours on Leary Way NW; please follow all detour guidance on site

You should anticipate:

  • Truck traffic on Leary Way NW as trucks bring materials and equipment to and from the site
  • Generators running during work hours to power pumps and equipment
  • Noise and vibrations typical of a construction site

Regular work hours will be Monday through Friday, from 7 am to 5 pm.


Crews have poured the upper portion of the Wallingford shaft walls and are now focused on forming the walls of the underground odor control facility, which will be housed on the east side of the shaft. Crews are also working inside the underground garage of the Brooks Building through September. They will continue using an air compressor to complete the work, which will be screened to muffle the sound. The team continues to coordinate this work with the building management.

You should anticipate:

  • Concrete trucks coming in and out of the site
  • Noise and vibrations typical of a construction site

Regular work hours will be Monday through Friday, from 7 am to 5:30 pm.

Queen Anne

Crews continue constructing underground vaults through the summer.  

Local closures and detours:

  • Localized Ship Canal Trail detour at least through summer 2023 (see map). The trail has returned to our pre-summer configuration. Please continue to remain alert when moving through this area.
  • West Ewing Mini Park parking closure through mid-2023

You should anticipate:

  • Trucks coming in and out of the site
  • Noise and vibrations typical of a construction site

Regular work hours will be Monday through Friday, from 7 am to 5 pm. Night and weekend work may occur.

Contact us

Please email with questions or comments or call our hotline at (206) 701-0233. You can also find information online at To support the community during active tunneling, we have changed our hotline hours to 24 hours a day, Monday through Friday.

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