Frequently Asked Questions
T-117 Cleanup Construction
When will the T-117 cleanup construction begin and how long will it take?
T-117 cleanup will be conducted in phases. In 2013, affected residential yards were cleaned up, followed by the river sediment and upland cleanup in 2014. Cleanup work for the adjacent streets is expected to begin in summer 2015.
To what extent is T-117 being cleaned up?
The T-117 site will be cleaned up to “unrestricted use” standards, which permits all possible uses for the site once cleanup is complete.
What will be designated work hours during the City’s next phase of construction in 2015?
Construction will generally take place during weekdays between the hours of 7am-7pm.
In the event that work needs to be performed outside of normal construction hours, the City and EPA will discuss this with the community.
How will air quality be addressed during active construction? Are there health risks from dust or disturbed contaminants?
To prevent blowing dust, the construction contractor will be required to use dust suppression controls, such as dampening surfaces with water spray and washing wheel wells of trucks before they leave the site. The project will also include air monitoring by the City, with oversight by EPA, to ensure environmental standards are met. Therefore, we do not anticipate increased health risks for residents near the T-117 site during construction due to dust.
What will happen with contaminated soil and sediment once they are removed?
Removed soil from the T-117 site will be placed in trucks and hauled out along a designated haul route. The most contaminated materials will go to a licensed hazardous waste disposal facility or landfill to be used as daily cover, likely in eastern Washington or Oregon. Most of the material, if not extremely contaminated, will go to municipal landfills to be used as daily cover.
Dredged river sediments were moved by barge to a nearby facility where they were then loaded into railcars and trucks for final disposal.
What will replace the material that is dug up and hauled away?
The dug up areas will be filled with clean materials imported from commercial sources. The amount of material removed as well as the type of replaced clean material will vary depending on the use of the location. For example, residential yards were backfilled with soil capable of supporting grass and plants. Streets will be backfilled with crushed rock capable of supporting a road.
The sediment area was backfilled with sand and habitat mix acceptable to support aquatic life, and the upland area was backfilled with a mixture of sand and gravel./p>
All fill material is subject to chemical testing to ensure that it meets the cleanup goals for the project.
Will you burn the dug up material?
No. We have evaluated other waste treatment technologies and found them either disproportionately expensive or that they would potentially result in secondary issues or concerns (like unacceptable emissions). Please see page 180 in the Engineering Evaluation and Cost Analysis
What portion of the cleanup will use a “cap?”
A capping method will not be used in this cleanup. All contaminated soil and sediment will be removed and replaced with clean material.
Has a haul route been determined, and will bus routes be affected?
Various haul routes are currently under consideration for the adjacent streets and stormwater phase of the cleanup. Community input will be requested and routes having the least impact on the community will be given special consideration. Once a haul route is determined, a traffic plan will be developed, and the community will be well-briefed on any detours. Although unlikely, King County Metro will be contacted to determine if there will be any affected bus routes in the area.
What other impacts can neighbors expect?
The City is making every effort to limit the impacts of the construction activities to businesses and residents in the neighborhood. However, during the construction activities, the following inconveniences are likely:
- Temporary street closures – You will be notified of the location and duration of any street closures at least two weeks in advance.
- Parking limitations – Some street parking will be temporarily limited due to equipment and construction activities. Additional parking spaces will be eliminated in order to accommodate rain gardens, new curbs and gutters and other City code requirements. Updates on parking limitations will be shared with the community throughout the project on a regular basis through listserv announcements, mailings and T-117 website postings.
- Noise – Every effort will be made to reduce the impact of construction noise during the project, with construction taking place on weekdays between the hours of 7am-7pm.
Will cleanup construction affect residents of South Park Marina?
The City’s project team is working closely with the Marina to minimize impacts, and they will be notified in advance of temporary work and permanent changes to their property.
Will the project team consider hiring local labor and using local resources?
The advertising, competitive bidding, and contract award process for the selected cleanup contactor will follow local and state public works protocols. The Port and the City, as governmental agencies, are not permitted by state law to direct contractors to perform selected hiring or purchasing.
When appropriate, the project will also continue to promote job hiring and training opportunities that support the Superfund project, such as King County/City of Seattle’s Brownfield Job Training Initiative and the Superfund Job Training Initiative.
After construction, what measures will be in place to avoid or reduce recontamination?
Long-term monitoring and reporting will be required after the completion of cleanup of T-117 and adjacent streets and yards. Some recontamination of the in-water sediments is likely, therefore, testing and monitoring will be conducted after the cleanup and, if necessary, a clean layer of sand will be placed in this area when the larger Lower Duwamish Waterway cleanup is being conducted. The recent Engineering Evaluation and Cost Analysis
(EE/CA) document concluded that recontamination of the upland area is not likely because the primary source of contaminated materials is being removed during cleanup.
As part of the City’s adjacent streets cleanup portion, a new stormwater collection and treatment system is being installed. This will reduce the potential of recontamination of the Lower Duwamish Waterway from stormwater run-off.
Are the diesel trucks and large equipment used for cleanup evaluated for emissions?
The contractor will be required to submit a green and sustainable remediation (GSR) plan, which includes a description of all GSR elements in the cleanup approach. These elements include emission reduction controls and policies and a transportation minimization and green transportation evaluation.
What was in the barrels and tanks uncovered during the uplands cleanup?
During the course of upland excavations, the Port discovered several unopened and damaged storage drums and barrels that were partially or totally full of liquid wastes. The liquid wastes were primarily heavy oils and other fuel oils (heating oil and diesel), some containing small percentages of other liquid wastes (solvents, gasoline, and PCB oils) likely used during operations of the previous businesses located on this site. Ultimately, all the discovered drums and their contents were chemically profiled and hauled off site for disposal at a licensed treatment facility or landfill.