Construction Updates Uplands/Sediments

Project Aerial Photos. Click to enlarge. (Photo Credit: Boeing)

Learn more about the Port of Seattle’s plan for habitat restoration and public shoreline access at the T-117 site on their website:

Project Update - April 2015

Upland and in-water construction is complete! Contaminated soil and sediment has been removed from the Port’s T-117 property. The site will remain fenced off until the restoration project is complete. Restoration is scheduled to begin in about a year.

In-water Work: In December, pilings were installed so the marina could replace docks that were removed during construction. Clean sand backfill was placed in the water to fill any valleys left by the removal of contaminated sediment.

Gravel borrow and rip rap (large rocks) were installed to protect the shoreline until restoration work begins.

Monitoring: The Port is currently developing a long-term monitoring and maintenance plan for the Site in collaboration with EPA.

Project Update - Dec 2014

This December, the Port of Seattle plans to complete the cleanup construction at Terminal 117! Work commenced on December 1 and should continue for about 3 weeks. The remaining work includes backfilling with clean sand, gravel borrow, and rip rap imported to the site via truck and by barge. Work will occur along the shoreline, either on the north bank slope or in the water, using similar equipment as last winter (e.g., trucks, barges, buckets, cranes). All contaminated material was removed last year; handling or generating of contaminated material is not anticipated for this remaining work.


Night Work: To take advantage of very low tides, one week of construction at night is planned, starting the night of Sunday, December 7 through Thursday night, December 11, between about 8 pm and 9:30 am. This work will consist of backfilling the unfinished slope area on the north end of the project, closest to the marina. Day work will also continue during this week.

Haul Route: Trucks will haul clean backfill material into the site via upper South Donovan Street and 17th Avenue South. Trucks will return to 14th Avenue South via Dallas Avenue South, turning right or left, depending on traffic.

Monitoring: Noise and light monitoring will resume using the same equipment as last year. Due to the short duration of this construction period we will not be posting weekly monitoring updates to the website, but data will be available upon request by emailing or calling the T-117 Information Line ( or 1-877-999-T117 [8117]). Additional air monitoring equipment will be available on standby if there is a potential concern, and any exceedances will be reported.

Project Update - May 2014

In May, we completed backfilling the Terminal 117 upland site with clean fill, installed security fencing, and hydroseeded around the perimeter. Hydroseeding will help hold the soil in place until the Port’s restoration work begins. The restoration construction is scheduled to start in Summer 2015.

Due to the completion of excavation, monitoring of air, noise, and light was discontinued as of May 9th.

The remaining work consists of restoring a retaining wall at the northeast corner between the Port's property and the South Park Marina, completing the fencing, and repairing the haul route. In addition, some limited in-water backfilling and upland slope work will occur in December 2014.

To mark this milestone in the T-117 project, an open house will be held on Sunday, June 29th at the Port’s Field Office. The celebration will run from 1:00 to 3:00 p.m. and include tours of the project site. Come learn about what’s been accomplished and what’s coming next at the Port’s T-117 property! This event will end just before the opening celebration of the South Park Bridge.

Project Update - March/April 2014

In the uplands, all contaminated soil excavation is complete. Work will continue through mid-May and will consist of completing backfilling, installing security fencing, and hydroseeding.

In-water cleanup work concluded for the season on March 22nd. We plan to return during the next work window (December 2014) to finish a small amount of backfilling and replace three marina piles. Where some residual contaminated sediment remains, the site will be backfilled and capped to protect from future disturbances and activities.

Occasionally, we had turbidity issues during the in-water work. This was due to one or more of the following: doing work along the bank in an area of the river that did not have much of a flow, placing backfill material during low-tides, and fines in the backfill material. Whenever we measured turbidity exceedances, adjustments were made to improve the best management practices and bring the turbidity back into compliance.

Light, noise, and air monitoring* were conducted throughout the 10-month project, and there were only two formal exceedances of performance screening standards, both of which were due to diesel exhaust. The first occurred at both of the site monitoring stations (see the green circles on the excavation map to the right) during a countywide burn ban. The second occurred when a project truck was operating too close to the south station. Noise and hydrogen sulfide levels occasionally exceeded the performance screening level at the perimeter, but because no complaints were received, they were not considered formal exceedances.

*The goal of the T-117 light, noise and air monitoring program is to ensure that impacts to the local community were minimized. Therefore, daily monitoring of light, noise and air was undertaken throughout the project.

Project Update - February 2014

In-water cleanup activities, including sediment dredging, continued on a daily basis through February and will continue through March 22, except between February 26 and March 3. This 6-day period marks a period when a higher percentage of juvenile Chinook salmon are believed to be migrating downriver past the site.

To ensure that in-water activities are not negatively impacting fish or other river life, water quality is checked several times throughout the day – both visually and by taking water samples. One concern is turbidity, or cloudiness of the water. Turbidity occurs naturally because of run-off, when rain causes sediment to wash into the river. Once washed into the river, these sediments are suspended in the water, making it look extra brown or cloudy. Turbidity increases during the heavy winter rains and in localized areas when work activities disturb river sediment. The T-117 project strives to keep turbidity to a minimum and to stop work and make immediate adjustments when dredging or backfilling cause increased turbidity.

Since June 2013, the truck route for upland construction had directed trucks through the South Park Boeing facility. Boeing allowed us use this route until March 1, 2014, when the route was moved to South Donovan Street. During the final upland construction in March, nearly all truck traffic will be bringing in clean fill and riprap for rebuilding the shoreline.

You can check the progress of the upland and sediment cleanup by clicking on the “Status of Soil Removal” map on the right. All completed sections are coded green, and those “in progress” are yellow. View air, light, and noise monitoring results by rolling your mouse over the green/black monitoring stations on the map.

Project Update - January 2014

In-water cleanup activities, including sediment dredging, continued daily throughout the month of January, and are expected to continue 7 days per week through early March. Contaminated sediment is pulled out of the water by a special bucket that contains the contaminated material until it is placed on a barge. That barge then travels down river to LaFarge, a facility that moves the sediment from barge to rail car. Finally, the contaminated sediment travels by train to the Roosevelt Regional Landfill in southern Washington.

Upland cleanup is more than 75% complete. The remainder of the contaminated soil should be removed from the site by the end of February. Backfilling with clean fill and rebuilding the shoreline with rip rap will continue through the middle of March.

For the latest progress on the upland and sediment cleanup, click on the “Status of Soil Removal” map on the right. All completed sections are coded green, and those “in progress” are yellow. View air, light, and noise monitoring results by rolling your mouse over the green/black monitoring stations on the map.

Project Update - December 2013

In-water cleanup activities, including sediment dredging, began in mid- December 2013 and are expected to last until mid-February 2014. As you may have noticed, there are multiple projects happening in the Duwamish concurrently. The Port continues to coordinate the in-water work with other nearby, in-water projects, including Boeing’s Plant 2 cleanup, Jorgensen cleanup, and King County’s construction of the South Park bridge.

Upland cleanup was frequently conducted at night throughout the month of December to take advantage of the low winter tides. Tides are lower in winter due to the Earth’s position along its elliptical orbit relative to the sun.

You may have noticed an increase in truck and trailer traffic in December. This is due to the need for delivery of local, clean fill from Auburn and Monroe to raise the elevation of the cleaned site. This is good news because it means that most of the contaminated soil has already been removed from the site, and it brings us one step closer to transforming the site into a public access and habitat area.

A small portion of the truck haul route was changed in order to excavate the final areas of the site (see grey cells “awaiting” excavation on the map at right). Trucks will continue to drive through the Boeing parking lot to Donovan, turn left onto 17th, then right on Dallas to enter the site. Trucks will use the standard route to exit.

Air monitoring results continue to fall below the limits set by the project, which themselves were significantly below the federal guidelines. Click on the map to the right to view real time air monitoring data and to view the excavation progress.

Project Update - November 2013

Thank you for your patience with the T-117 uplands/sediments cleanup! Uplands work is finally winding down. We expect to be done with all excavation by January and we will be placing backfill material and grading into February.

The cleanup has been full of surprises (see September’s update below) and we have had to stay nimble throughout the construction process. Recently construction along the riverbank often went round the clock to take advantage of the lowest tides at night. We also saw an increase in truck traffic in November because we switched from using rail cars to trucks and trailers to haul contaminated soil to the landfill.

In-water cleanup activities, including sediment dredging, will begin in December. The dredging equipment and barge are in the water and ready to go. South Park Marina has temporarily moved some of their docks in preparation for the dredging. The Port frequently coordinates with Boeing, King County, and the Muckleshoot Tribe to ensure limited impact to people, the river, and other construction projects.

We appreciate the ongoing support we have received from Boeing throughout the cleanup. Not only have they allowed us to park construction trailers in their parking lot to enable easier access for the construction workers, but they have also allowed us to use part of their parking lot as a haul route. Both actions have helped minimize traffic through the adjacent neighborhood.

Air monitoring results continue to be under the limits set by the project, which themselves were significantly under the federal guidelines. However, one exceedance of black carbon (an indicator of diesel exhaust) occurred the week of Thanksgiving. This elevated reading was consistent with high diesel exhaust readings in the air throughout King County due to an inversion in the region, as confirmed with the Puget Sound Clean Air Agency (PSCAA). A review of daily work activities found no apparent change on the job site that would have contributed to the higher readings. The next day, the readings returned to normal range. Click on the map to the right to view real time air monitoring data and the excavation progress.

Project Update - October 2013

Cleanup construction continued along the north and south riverbanks. To best reach these areas, construction was conducted during the lowest tides of October, which occurred at night. Artificial lighting was used and light was monitored during this time.

In-water cleanup activities, including sediment dredging, are scheduled to begin in early December. In-water work will begin by removing old wooden piling and making some minor dock changes at the Marina.

Air quality and noise are monitored daily during all construction activities. Air quality levels are consistently below the project guidelines. For the latest data, click on the excavation map on the right and roll your mouse over the circles.

Project Update - September 2013

Air quality and noise are monitored daily during all construction activities.Levels are consistently below the limits set by the project – well below the Federal and State guidelines. For the latest data, click on the excavation map on the right and roll your mouse over the circles.

From August through early September, the contractor uncovered an unanticipated underground storage tank and approximately 40 barrels containing unknown product on-site. Emergency contracts have been awarded to hazardous waste contractor NRC and DH Environmental to characterize and handle these and other unforeseen materials to allow the remediation of the site to continue. These contractors will stay involved throughout the excavation phase of the project in case other unanticipated materials are discovered.

Although the T-117 site was investigated thoroughly before cleanup began via 250 borings, ground penetrating radar, and other methods, these unexpected materials were still discovered. Most of these product-filled barrels were found under the riprap, or the large rocks and
rubble protecting the river bank, making these materials difficult to locate.

All of the unanticipated materials have now been sampled and characterized for proper disposal. There have been no impacts or threats to the community from the discovery and handling of recent unanticipated materials.

Project Update - August 2013

Air quality and noise continue to be monitored daily during construction activities. Levels are consistently below the limits set by the project, which are below the Federal and State guidelines. Scroll your mouse over the circles on the excavation map at right for the latest air monitoring data.

Sheet piling along the shoreline is complete, which will be used to isolate the contaminated upland soil from the river. In-water construction work is scheduled to begin in December 2013.

As of August 19th, construction on the T-117 cleanup site was placed on temporary suspension due to the discovery of unanticipated materials (underground storage tanks and buried drums containing liquid waste and other products). (Click here to read the “Declaration of Emergency” issued by the Port.) When a drum or tank is discovered containing unknown product, the impacted area of the site is cordoned off and a hazardous-waste response company (NRC located in South Park) is brought in to assess and remove the material before construction in the area can resume. The temporary suspension order will remain until the removal of the recently discovered unanticipated materials is complete. Meanwhile, the site has been stabilized and ongoing monitoring continues. Some soil hauling or other site maintenance may occur during this period. There have been no impacts or threats to the community from the tanks/drums or the materials they contain.

Project Update - July 2013

Construction is well underway. In the last month, three buildings were demolished and excavation of contaminated soil began. Sheet piling continues to be installed to keep water out of the excavation areas; contaminated soil is being hauled offsite to a landfill. Air quality and noise are monitored daily. See excavation map at right for weekly updates on our soil excavation and community air monitoring progress.

Soil spill outside the site: On July 9 at approximately 12:30pm, less than 1 cubic yard of material was spilled from a truck on 14th Ave S between Trenton and Henderson Streets. On its route to the landfill, the hinge of a truck/trailer tailgate reportedly broke and caused this small amount of soil to spill from the truck bed. The spilled soil was placed back into trucks and removed from the street within 10 minutes. Street sweepers and water trucks continued for about 2 hours removing any residual soil from the street.

Project Update - June 2013

Construction is underway!
The upland portion of the cleanup began June 2013. Click here for an interactive map showing cleanup progress, including monitoring data. Uplands cleanup is scheduled to be complete by September, with river bank and sediment cleanup starting in December 2013.

Project Update - May 2013

T-117 Community Resource Guide now available
Read the Community Resource Guide to learn about upcoming cleanup construction for the uplands, river bank and sediment, including what you can expect and how the Port will keep the South Park community safe during

Superfund Job Training Initiative

The EPA's Superfund Job Training Initiative (SuperJTI) is an environmental remediation job readiness program that provides free training and employment opportunities for citizens living in communities affected by Superfund sites.

Additional information about SuperJTI available here: