Investing in the Health of the Sound and the Future of Our Region

Welcome to the Ship Canal Water Quality Project website! We’re happy you’re here.

We will continue to share updates about construction progress on this website, as they become available.

Follow MudHoney, the 18-ft tunnel boring machine, on its journey!

shows progress of TBM, mudhoney, from Ballard to Wallingford. Currenlty about halfway between ballard and east ballard

Tunneled 2,860 of 13,946 Feet

Last updated May 12, 2022

What’s happening now?

Intermittent lane reductions on Leary Way NW through approximately May 2022 [updated on 4/12/22]

Any new built structures need to have solid ground to live on. Jet grouting, one of many effective ways to stabilize and strengthen soil, is the way we will prepare the soil for upcoming Fremont construction.

To complete this work, we will need to close some traffic lanes on Leary Way NW from November through May 2022. Two lanes will always remain open (one lane in each direction), and when work is not taking place, we will leave all lanes open when possible. Access to all businesses will be maintained. If you are commuting through this area, consider taking our optional detour during this work.

April 12, 2022 update:

The work related to soil stabilization in Leary Way NW is complete and the contractor has completed pavement restoration on the south half of the roadway. Starting Monday April 18, the contractor plans to shift traffic to the south half of the roadway to begin utility restoration work in the north half of NW Leary Way. This work will include intermittent closures over the next few weeks. NW Leary Way is expected to be fully reopened by mid-May.

construction map showing lane reductions — (Click or tap to enlarge) Updated April 2022

MudHoney has resumed tunneling

A MudHoney tunnel boring machine operator, wearing a bright yellow sweater and hard hart, looks at four computer screens on a gray wall. There are a variety of buttons below and to the side of the screen; some are lit up. — MudHoney operator in the control room driving the tunnel boring machine. (Click or tap to enlarge)

After a planned pause, MudHoney, our 18-ft diameter tunnel boring machine (TBM), resumed tunneling on February 7. Before starting MudHoney, we sent our engineers and workers inside the excavation chamber under compressed air to check on the condition of the cutting tools. Pressurized air allows workers to safely enter the cutterhead chamber without groundwater entering the TBM. The pressure here is equivalent to recreational scuba diving at an 80-ft water depth. There are several more maintenance stops planned along the way.

For more information about how we keep MudHoney on track when we can’t “see” where we are going, take a look at one of our previous listservs.

Building underground structures throughout the project corridor

This photo shows crews excavating a large rectangular hole in the ground in Queen Anne. Steel bracings reinforce the corners of the rectangular hole. — Diversion structure excavation at the Queen Anne project site. (Click or tap to enlarge)

Most of our city’s wastewater system is underground, which means a lot of digging during a project like this. To build a system that will keep sewage mixed with stormwater from entering the Ship Canal during heavy rains, there are supporting structures we need to construct in addition to our large and awesome storage tunnel (thanks for all the work so far, MudHoney!). In 2022, we’ll be building these supporting structures at our East Ballard, Queen Anne, and Fremont sites. They include vaults, drop shafts and diversion structures.

Check out our glossary for a deep dive into these structures and other more technical elements of our project!

View archived project announcements

Project Area (Click or tap image to enlarge)

Click on the project areas to learn more

About the project

Seattle Public Utilities and King County Wastewater Treatment Division are building an underground storage tunnel to significantly reduce the amount of polluted stormwater (from rain) and sewage that flows into the Lake Washington Ship Canal, Salmon Bay, and Lake Union from our sewer system.

Learn more about the project

In some parts of Seattle, sewage and stormwater (rain) share a set of pipes; this is called a combined sewer. During heavy rains (What? Rain? Here?) the water often exceeds the pipes’ capacity (known as an overflow to us sewer nerds), sending untreated sewage (yep, that means poop) and stormwater into the Ship Canal. These overflows can harm fish, wildlife, and the environment, and can contain pollution.

During a heavy storm, the new tunnel will capture and temporarily store more than 29 million gallons of untreated stormwater and sewage until the treatment plant is ready for it. The tunnel will improve water quality regionally by keeping more than 75 million gallons of polluted stormwater (from rain) and sewage on average each year from flowing into the Lake Washington Ship Canal, Salmon Bay, and Lake Union. Based on data from the last five years, the Ship Canal Water Quality Project would have removed about 70% of SPU’s total combined sewer overflow volume.

This storage tunnel (currently under construction) is one of several projects that comprise the Ship Canal Water Quality Project. The Storage Tunnel construction contract value is $255M. The total cost for the overall Ship Canal Water Quality Project is $570M and right now there is a 65% chance that our total cost will be at or below $570M. As the project moves forward, the team will update the cost model and the confidence level will change over time.

Check out this video for an overview of the project.

During dry weather conditions, sewage flows directly to a treatment plant. (Click or tap image to enlarge)

During heavy rain, sewage and stormwater can overflow into a nearby body of water. (Click or tap image to enlarge)

Tunnel

Since the 1800s, 150 tunnels spanning over 70 miles have been constructed in Seattle for sewers, utility corridors, and transportation needs. The Ship Canal Water Quality Project includes a 2.7-mile, 18-ft and 10-in internal-diameter tunnel that will extend from Ballard to Wallingford. Tunneling operations will start in Ballard. The Ballard vertical access shaft construction started in 2020 with tunneling is planned through 2022.

Learn more about the tunnel

The purpose of the tunnel is to collect and hold stormwater and sewage flows which would normally overflow into the Ship Canal. Along the tunnel path, there will be five vertical shafts (in Ballard, East Ballard, Fremont, Queen Anne, and Wallingford). They will collect stormwater and sewage flows from each basin and send them approximately 40 – 80 ft below ground into the new storage tunnel. In order to bring flows from Queen Anne into the storage tunnel, SPU will build an 8-ft diameter conveyance tunnel underneath the Ship Canal connecting the vertical shafts in Queen Anne and Fremont. For the final piece of the SCWQP, SPU will install new pipes to connect the existing sewer systems to the new shafts.

Diagram explains how the new Ship Canal Storage Tunnel works — How the new Ship Canal Storage Tunnel works. (Click or tap image to enlarge)

Meet our Tunnel Boring Machines (TBMs)

In addition to MudHoney, our roughly 18-ft diameter tunnel boring machine that will construct the storage tunnel, did you know that our project will also build a couple of other, smaller tunnels? We will be using smaller tunneling machines for two conveyance tunnels, one will go under the Ship Canal between Fremont and Queen Anne, and one in Ballard. Both of these conveyance tunnels will be used to carry flows to the storage tunnel. The Ballard tunnel is still in the design phase and won’t be constructed until 2023.

See the table below to learn more about the differences between these TBMs and check out our storage tunnel TBM factsheet for more information!

A large red and white tunnel boring machine at a construction site. — MudHoney, our 18-ft storage TBM | Click to enlarge

A picture containing indoor, engine — Our smaller 8-ft conveyance TBM | Click to enlarge

Tunnel Boring Machine Comparison

	MudHoney, 18-ft Storage Tunnel TBM	8-ft Conveyance Tunnel TBM *Note that we do not yet have information about the Ballard TBM
Type of Machine	Earth Pressure Balance Pressurized face TBM	Slurry pressurized face TBM
Manufacturer	Germany	Germany
Age	Newly manufactured in 2020	Manufactured in 2014 and refurbished from King County's Fremont Siphon Project
Length	14,256-ft	646-ft
Length of TBM shield This is the part of the machine that isolates the TBM equipment from the surrounding ground	31-ft 2-in	22-ft 7-in
Number of cutterhead tools	18 double-disc cutters 48 scrapers 16 bucket cutters	12 double-disc cutters 16 scrapers 14 chisels
How do we operate the TBM?	Operated by crews in a control room inside the front of the TBM	Operated remotely by crews above ground
Number of staff needed to operate	10-15 people	6-10 people
Diameter of TBM The TBM has to drill a hole larger than the final tunnel size to have space to build the concrete tunnel liner	21-ft 8-in	9-ft 10-in
Finished tunnel diameter	18-ft 10-in	8-ft 0-in
Tunnel construction	6 concrete segments combined to form a ring	Concrete reinforced pipe

Naming MudHoney

In early 2021, we asked the community to help us name the 18-ft storage tunnel boring machine (TBM). We received over 1,200 TBM name submissions and over 30,000 votes! MudHoney was the ultimate winner. The name was painted on the front of the TBM by Devin Finley in April 2021.

Devin Finley is a muralist who specializes in large scale inspired murals. He started as a graffiti artist at age 15 because he loved street accessible art. He became a professional muralist in 2013 and works on both private and public projects. He likes working with clients and audiences to develop engaged and meaningful concepts. His project “MUDHONEY” was painted onto the project’s tunnel boring machine on April 5, 2021. The TBM was named "MudHoney" and Devin used lettering and water droplets to connect the enormous machine, one of Seattle’s famous grunge bands, and rain-- which is part of the reason for the project.

Four individuals wearing sweaters and hardhats stand in front of a tunnel boring machine that has the word MudHoney drawn in yellow and black letters — Seattle based-band Mudhoney and the Ship Canal Water Quality Project Tunnel Boring Machine! | Click to enlarge

Learn about ground monitoring

Ballard

Learn more about the Ballard site

Ballard will be home to the western end of the tunnel and above-ground facilities supporting the tunnel. Tunnel boring will start at this site and move toward Fremont and Wallingford.

We started work at our site near 24th Ave NW and Shilshole Ave NW in 2018 to prepare for tunneling. This work included soil remediation, utility relocation, 24th Ave Pier replacement, and replacing a sewer outfall pipe.

Project elements in Ballard include:

A new 107-ft deep, 80-ft diameter vertical shaft, also called a drop shaft, to hold pump station equipment and carry sewage and stormwater into the new storage tunnel
New conveyance pipes along NW 56th St, 28th Ave NW, and 24th Ave NW to connect the existing sewer and stormwater overflow pipes to the storage tunnel
A large pump station that will take the flows from the tunnel and send them to West Point for treatment
A new 24th Ave Pier containing art inlays by artist Christian French (complete)

After construction is completed at the Ballard site, you can expect to see:

Ballard Pump Station (not publicly accessible):
- 80-ft illuminated tower with above- and below-ground mechanical equipment and odor control
- Maintenance yard with vehicle access
- An urban tree farm
- Landscaping
- Fencing
24th Ave NW Restoration (publicly accessible)
- Green stormwater infrastructure
- Pedestrian improvements, including seating and bike racks
- Parking improvements
- Street-end improvements
- Public art by artist Jeffrey Veregge

To learn more about the Ballard project site, read our fact sheet.

aerial map of area between 24th avenue North West and Shilshole Avenue Northwest. Tunnel barging operations are southwest of the 24th avenue pier in Salmon Bay. Dotted lines along 24th Avenue Northwest and Northwest 56th Street indicate locations for conveyance pipe alignment and microtunnel placement. A dark blue line that runs through Shilshole Avenue Northwest denotes the storage tunnel. — Construction area map (Click or tap image to enlarge)

About the Ballard Pump Station concept

Our designers have been inspired both by our underground infrastructure and the Ballard community. The cylindrical shape mirrors the pump station and below-ground equipment space. The frame around the building echoes the industrial feel and scaffolding of Ballard's shipyards. Near the tower will be smaller buildings for equipment as well as parking for our amazing maintenance crews.

Artwork developed byJeffrey Veregge, from the Port Gamble S'Kallam Tribe, celebrates the Coast Salish heritage and historical use of the area.

To learn more about the Ballard project site, read our fact sheet or check out this introductory video. For more details about future site improvements, take a look at our Ballard Pump Station Flickr album.

An animated depiction of the future Ballard pump station during a sunset. The cylinder-shaped pump station contains an argyle-styled fence that encases the pump station itself. — Rendering of future Ballard Pump Station. (Click or tap image to enlarge)

An animated depiction showing someone walking down a pier towards a vegetated area that has a tall cylindrical building with a cross-hatched steel frame on the outside. On the left side of the pier, there is a person standing on a beach with two paddle boards. To the right side of the pier there is another beach with boulders scattered across it. In the background there are people walking down a sidewalk with a fence on the right and trees on the left. — Design concept for the Ballard Pump Station. This view shows both the pump station design and the planned improvements on the 24th Ave NW street-end. (Click or tap image to enlarge)

Learn more about Ballard Conveyance

Once the new storage tunnel is built, crews will install a 2,000-ft long, 60-in diameter pipeline in Ballard along 24th Ave NW, NW 56th St, and 28th Ave NW to convey polluted stormwater and sewage from the Ballard neighborhood into the storage tunnel.

When this work starts in 2023, you can expect single-lane and full-street closures, intersection closures, and parking restrictions on impacted blocks. We will provide more updates and information about these impacts as we get closer to the start of this work.

What to expect during near-term construction

Ballard schedule

projected construction schedule. Includes Construction methods and milestones, the year each construction milestone and method will take place. A blue star under the year 2025 denotes Storage tunnel operationa — Ballard construction schedule (Click or tap image to enlarge)

Crews will generally work Monday through Friday from 7 am to 5 pm
- Possible weekend and nightwork to maintain progress
Parking restrictions along the east side of 24th Ave NW so construction trucks can exit the work site
Trucks and large equipment moving in and out of the work zone
Short interruptions on Shilshole Ave NW for trucks entering the work zone, and on 24th Ave NW for trucks exiting the site; please pay attention to flaggers
Noise typical of a large construction site
Access to all buildings and businesses will be maintained

East Ballard

Learn about the East Ballard site

Project elements in East Ballard include:

A new 55-ft deep, 10-ft diameter vertical shaft, also called a drop shaft, near the intersection of 11th Ave NW and NW 45th St to carry sewage to the new storage tunnel
A new below-grade structure to house mechanical, electrical, and odor control equipment
A new diversion structure, gate vault, and conveyance pipes to connect the existing sewer and stormwater overflow pipe to the storage tunnel

To learn more about the East Ballard project site, read our fact sheet.

aerial map shows area on Northwest 45th Street and is between 11th Avenue North West and 9th Avenue Northwest. Grey dotted lines along 45th Avenue Northwest and indicate the future missing link route, orange dotted lines along 45th Avenue Northwest indicate the proposed trail detour and green dotted lines indicate the Burke-Gilman Trail. The solid blue line on 11th Avenue Northwest indicates underground pipes.. — Construction area map (Click or tap image to enlarge)

What to expect during construction

East Ballard schedule

Crews will generally work Monday through Friday from 7 am to 5 pm
- Possible weekend and nightwork to maintain progress
NW 45th St will remain closed until further notice
Construction-related noise, traffic, dust, and vibrations
The Burke-Gilman Trail will be detoured to the north side of NW 45th St
Periodic traffic impacts to 11th Ave NW and NW 45th St, including one-lane and full-road closures, now through 2022
Flaggers will help direct traffic during work hours
Parking restrictions

Fremont

Learn about the Fremont site

We anticipate construction of the tunnel to take place through 2022. During this time, there will be a large crane on-site and an uptick in deliveries for the casing pipe construction.

Additionally we’ll begin construction of the diversion structure in 2nd Ave NW. We anticipate 2nd Ave NW will be closed south of Leary Way NW through the end of 2022.

Project elements in Fremont include:

A new 85-ft deep, 32-ft diameter vertical shaft, also called a drop shaft, to carry sewage and stormwater into the new storage tunnel
A new diversion structure and conveyance pipe to connect the existing sewer and stormwater overflow pipes to the storage tunnel
A new 8-ft diameter conveyance tunnel under the Ship Canal to carry flows from Queen Anne to the storage tunnel
A new underground structure to house mechanical, electrical, and odor control equipment

A graphic rendering looking inside an eight-foot diameter storage tunnel. Three smaller white circles with colored borders inside the larger gray tunnel indicate different elements of the tunnel. Gray lines inside the tunnel represent temporary pipes. — Click or tap image to enlarge

Artists Preston Singletary and David Franklin collaborated on artwork for the Fremont and Queen Anne sites. This artwork is planned to be installed in late 2023.

To learn more about the Fremont project site, read our fact sheet.

aerial map of the project sitesituated between Leary Way Northwest and the Burke Gilman Trail. The dotted orange line along first avenue Northwest and Northwest 36th Street denotes the pedestrian detour. A small blue line that runs from the project area and across the Ship Canal represents the microtunnel placement. — Construction area map (Click or tap image to enlarge)

What to expect during construction

Fremont schedule

Crews will generally work Monday through Friday from 7 am to 5 pm
- Possible weekend and nightwork to maintain progress
Full closure of NW 36th St between Leary Way NW and 3rd Ave NW
Closure of 2nd Ave NW between Leary Way NW and Canal St
Temporary roadway detours on streets adjacent to the project area. Leary Way NW will remain open to traffic, but several lanes will be temporarily closed for construction.
Pedestrian sidewalk detour on north side of Leary Way NW
Increased truck traffic
Parking restrictions near work zone
Burke-Gilman Trail to remain open except temporary impact during conduit installation (likely one week)

Queen Anne

Learn about the Queen Anne site

Project elements in Queen Anne include:

A new 8-ft diameter tunnel under the Ship Canal to carry stormwater and sewage from Queen Anne to the new storage tunnel
A new 74-ft deep, 20-ft diameter vertical shaft, also called a drop shaft, to direct flows into the new 8-ft diameter tunnel
New structures and conveyance pipes to connect the existing sewer and stormwater overflow pipe to the new vertical shaft

Artists Preston Singletary and David Franklin have collaborated on artwork for the Fremont and Queen Anne sites. This artwork is planned to be installed in late 2023.

To learn more about the Queen Anne project site, read our fact sheet.

aerial map of project site situated along Third Avenue West and West Ewing Street. Green boxes within the project area indicate the following: underground pipes, cabinet, underground facility and drop shaft. A small blue line that runs from the project area and across the Ship Canal to Northwest 36th Street in Fremont represents the microtunnel placement. — Construction area map (Click or tap image to enlarge)

What to expect during construction

Queen Anne schedule

Construction-related noise, traffic, dust, and vibrations
Vehicle, pedestrian, and bicycle wayfinding and detour signage
Increased truck traffic along W Nickerson St and 3rd Ave W
Parking restrictions and roadway detours
Ship Canal Trail detour through summer 2023
Closure of West Ewing Mini Park and associated parking lot

Wallingford

Learn about the Wallingford site

Wallingford marks the eastern end of the Ship Canal Water Quality Project and the location where tunneling will end underneath N 35th St and Interlake Ave N. Construction will take place on Stone Way N, N 35th St, and Interlake Ave N.

Project elements in Wallingford include:

A new 56-ft deep, 32-ft diameter vertical shaft, also called a drop shaft, near Stone Way N and N 35th St to convey stormwater and sewage into the tunnel
New conveyance pipe installation along Stone Way N and N 35th St to connect the existing sewer and stormwater overflow pipe to the storage tunnel
A new small, above-ground electrical building near 3500 Interlake Ave N
New underground structures to house mechanical, electrical, and odor control equipment
Site and roadway restoration
Public art by Ryan! Feddersen

After construction at the Wallingford site is complete, SPU will retain ownership of the southern portion of the site. The site will be mostly fenced to secure utility equipment. The fenced area will house an aboveground electrical building, and a number of large, underground structures attached to the storage tunnel.

The design for the Wallingford site is complete. During design, our landscape architects reviewed the planting schemes for the North Transfer Station and the Carr Place Play Area. Their goal was to create a site that was unique to the neighborhood but still complemented the aesthetic of nearby open spaces.

Artist Ryan! Feddersen will design and install the artwork at this project site.

To learn more about the Wallingford project site, read our fact sheet.

A graphic rendering that depicts two individuals sitting on a concrete wall in front of landscaping and a black fence at the future Wallingford site. — Rendering of future Wallingford site. (click to enlarge)

A graphic rendering depicting a black electrical building at the future Wallingford site. A bicyclist is riding by the building on the road. — A rendering of the electrical building for the future Wallingford site. (click to enlarge)

An aerial landscape rendering that depicts the future Wallingford site. A black fence surrounds vegetation and buildings. The street to the left of the rendering is Interlake Avenue North and the street below the rendering is North thirty-fifth Street. — A landscape rendering plan for the future Wallingford site. (click to enlarge)

aerial map project site situated at the intersection of Interlake Avenue North and North 35th Street. A dark grey line that runs west from the project site along N 35th Street indicates the storage tunnel. — Construction area map (Click or tap image to enlarge)

Learn more about Wallingford Conveyance

Once the new storage tunnel is built, crews will install a 213-ft long, 36-in diameter pipeline along Stone Way N and a 412-ft long, 42-in diameter pipeline along N 35th St to convey polluted stormwater and sewage from the Wallingford neighborhood into the storage tunnel.

During construction, you can expect lane closures, traffic detours, detours of Metro bus routes 31, 32 and 62, and parking restrictions on N 35th St and Stone Way N, with several months of work in the intersection of Stone Way N and N 34th St. We will provide more updates about these impacts as they become available.

What to expect during construction

Wallingford schedule

Construction-related noise, traffic, dust, and vibrations
Sidewalk closure on the east side of Interlake Ave N
Parking restrictions and roadway detours
Northbound lane impacts on Interlake Ave N with flaggers present to direct traffic
We anticipate back-to back-closures for Stone Way and N 35th St. First, Stone Way, between N 35th St and 34th St, will be closed to vehicles for at least nine months. Then, the intersection at Stone Way and N 35th St will be closed for approximately one month. Finally, N 35th St, between Interlake Ave N and Stone Way, will be closed for at least seven months, with local access maintained. We will provide additional information as we get closer to these closures.
Removal of some trees in the project area

Investing in the Health of the Sound and the Future of Our Region

Welcome to the Ship Canal Water Quality Project website! We’re happy you’re here.

Follow MudHoney, the 18-ft tunnel boring machine, on its journey!

Tunneled 2,860 of 13,946 Feet

Intermittent lane reductions on Leary Way NW through approximately May 2022 [updated on 4/12/22]

MudHoney has resumed tunneling

Building underground structures throughout the project corridor

Click on the project areas to learn more

About the project

Tunnel

Tunnel Boring Machine Comparison

Ballard

Learn more about the Ballard site

Ballard schedule

East Ballard

Learn about the East Ballard site

East Ballard schedule

Fremont

Learn about the Fremont site

Fremont schedule

Queen Anne

Learn about the Queen Anne site

Queen Anne schedule

Wallingford

Learn about the Wallingford site

Wallingford schedule

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