Ship Canal Water Quality project update 12/14/20

City of Seattle, Washington sent this bulletin at 12/14/2020 08:08 AM PST

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Dear neighbors,
We anticipate completing our secant pile walls in Fremont and Queen Anne this month. Thank you for your patience during this important, yet noisy, activity.

In Wallingford, secant pile wall preparation will begin this month. Read on for more information about what this work will look like, and if you haven't already, check out this video from a prior King County project that shows secant pile wall construction underway.

Visit our Flickr page to see photos of recent construction activities.

Ballard

Over the weekend, we completed the project's largest concrete pour for the shaft floor (see photo above and more here). The floor is 14-ft thick and 87-ft wide and required deliveries from about 350 concrete trucks! For the next few weeks, we'll be installing final concrete walls and electrical equipment. This work is anticipated to last through early January. Additionally, we expect to receive and assemble equipment for tunneling, such as cranes, between January and April. During this time, you can expect:

Trucks coming in and out of the site to deliver equipment.
Intermittent days of large concrete pours. On these days there will be many trucks delivering concrete to the site, back to back. Work on these pour days may occur well beyond regular working hours due to the amount of concrete that needs to be placed. We anticipate the next large pour to take place in late December.

Working hours are expected to be 7 am - 5 pm Monday through Friday. Night and weekend work may occur to maintain progress.

East Ballard

Crews will begin a new method of soil stabilization work over the next few weeks. New equipment will arrive on site and crews will prepare the work area on NW 45^th St. For the next few weeks, you should anticipate:

NW 45th St closed to traffic; vehicles must detour onto NW 46th St.
Burke-Gilman Trail users remain detoured to the north side of NW 45th St; flaggers to help direct traffic during daytime working hours. Please follow all detour guidance on site. Bicyclists must cross train tracks at 90-degree angles. Please use extra caution in wet weather as ramps may be slippery.
11th Ave NW will remain open now through Dec. 31 to lessen impacts to holiday traffic in the area.

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

See anticipated traffic impacts through 2022 on our website.

Fremont

Secant pile wall construction should wrap up just before Christmas. Once this activity is complete, crews will dewater the site (pumps inside drilled wells are used to draw down groundwater levels) and will excavate the shaft. Excavation should be relatively quieter, and we will provide more information about that activity in our next update. For the next two weeks, you should anticipate:

Heavy equipment on site such as the drill rig, an oscillator, and a crane.
Trucks coming in and out of the site to haul away excavated material and deliver concrete.
Noise and vibration from the drill rig. You may be able to feel the vibration which is expected. We are monitoring vibration levels on site to ensure they are within allowable levels.
NW 36th St between Leary Way NW and 3rd Ave NW closed (through remainder of the project).
Pedestrians detoured to the north side of Leary Way NW.
A pump and bypass system running 24/7 to re-route an existing drainage line around the secant pile construction. This system is powered by a generator and will be in place through the end of the year.

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

Wallingford

For the next few weeks, crews will be grading and prepping the site for secant pile wall construction. Crews will dewater the site (pumps inside drilled wells are used to draw down groundwater levels), bring in equipment and will begin excavating for the secant pile guide walls.

For the remainder of the month, you should anticipate:

More equipment staged on site.
Noise from the drill rig installing dewatering wells.
Noise and vibrations from excavation and concrete trucks moving in and out.

In January, we’ll start secant pile wall construction. In an effort to be as transparent as possible, we want to let you know it will involve several months of intense, loud construction with long work days at the project’s Wallingford site.

During secant pile construction you can expect:

Heavy equipment on site such as the drill rig, an oscillator, and a crane.
Trucks coming in and out of the site to haul away excavated material and deliver concrete.
Noise from the drill rig. This rig is loud and work will start as early as 7 am as allowed by City of Seattle code. We start early in the morning to allow the contractor to complete more of the work during daylight hours to improve safety, to maximize the use of expensive, heavy machinery each day and, to complete work as efficiently and cost-effectively as possible.
Vibration from the drill rig. You may be able to feel the vibration in your home or business. This is expected. We are monitoring vibration levels on site to ensure they are within allowable levels.
Normal work hours are from 7am to 5pm, Monday through Friday, although work may extend into the early evening, on occasion to complete the concreting of a pile. It’s possible the contractor may also work on Saturdays as needed.

Learn more about the Wallingford secant pile wall.

Queen Anne

Secant pile wall construction nearing completion

Secant pile wall construction is complete! Over the next few weeks, we'll dewater the site (pumps inside drilled wells are used to draw down groundwater levels), demobilize equipment, and begin excavating the vertical shaft. During this time, you should anticipate:

Trucks coming in and out of the site to haul away excavated material.
Noise and vibrations typical of a construction site.
The West Ewing Mini Park parking lot closed. This closure is anticipated to last through mid-2023.
A localized Ship Canal Trail detour through summer 2022 (see map).