Consolidated Freightways Seattle

Ecology held a 30 day comment period (November 17 - December 16, 2022) to delist this Site from the Hazardous Sites List. 

Ecology issued a No Further Action Letter on December 27, 2022.  

The Site will be delisted from the Hazardous Sites List (HSL) February 2023.  The HSL is published twice a year.  It includes additions to the list, changes in remedial status of sites on the list, and removals from the list Model Toxics Control Act.

Site Background
Model Toxics Control Act
Site Cleanup in progress
Contaminants of Concern
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The Site is located within King County’s Industrial Zone with an area of 13.58 acres. The Property was constructed as a military barracks-type facility in 1943, and was transferred to a construction-trucking business center in 1956.  The trucking business was operated until early 2017.  A land redevelopment project began in June 2017, that included building a three-floor industrial warehouse and the associated construction.

Multiple Site investigations discovered and confirmed that petroleum contaminants in soil and groundwater originated from releases of twelve leaking underground storage tanks (LUSTs) and operations of the former construction-trucking business.  In addition, vinyl chloride (VC) in the groundwater at the Site was determined as the result of migration from the adjacent Model Toxics Control Act (MTCA) cleanup site, West of 4th, to the north.     

The Model Toxics Control Act (MTCA) is Washington’s environmental cleanup law. It provides requirements for contaminated site cleanup and sets standards that protect human health and the environment. Ecology enacts the MTCA and oversees cleanups.

​The MTCA site cleanup process is completed in steps over a variable timeline.

Since 1988, numerous cleanup actions were conducted at the Site, which included:

• Removal of contamination sources. Between 1988 and 2017, 12 gasoline, diesel, lube oil, waste oil, and heating oil USTs were decommissioned, and approximately 6,480 tons of the contaminated soil were removed and disposed of off-Site.

• Extraction of contaminated groundwater.  Approximately 320,000 gallons of the impacted groundwater were extracted, treated, and disposed during the soil removals.

• Performance of enhanced natural attenuation remediation.  Oxygen release compound was placed at the bottoms of the excavations as a soil amendment to promote the biological degradation of the residual COCs in groundwater.

• Implementation of the confirmational monitoring for groundwater quality.  Following completion of the contamination source elimination, groundwater samples were collected from eight monitoring wells to analyze the COCs between 2018 and 2022.  

• The analytical data demonstrated that all the COCs, except for VC, in the samples were at concentrations below either the applicable cleanup levels or the laboratory detection limits for four consecutive quarterly monitoring events. 

• Study of the VC plume occurrence at this Site.  A Site study was performed to determine the source of VC in the groundwater at this Site.  The study concluded that presence of VC in the groundwater at the northern portion of the Property originated from the neighboring MTCA cleanup Site, West of 4th.

SOIL

Total petroleum hydrocarbons as gasoline (TPH-G)

Diesel (TPH-D)

Oil (TPH-O) range organics

Benzene, Ethylbenzene, Toluene, and Xylenes (BETX) 

GROUNDWATER

TPH-G, TPH-D, TPH-O, BTEX, 

Vinyl Chloride 

What's In My Neighborhood shows contamination cleanup sites in Washington state. 

Ecology encourages cleanup of these sites to protect the health of people, plants, and animals. Cleanups are projects that remove, treat, or contain potentially harmful substances.

To report an environmental problem or concern, any time, day or night, use the online reporting form.

Counties: Island, King, Kitsap, San Juan, Skagit, Snohomish, and Whatcom
Email: nwroerts@ecy.wa.gov
Phone: 206-594-0000

Ecology is committed to providing people with disabilities access to information and services. To request an ADA accommodation, contact Ecology by phone at 360-407-6831 or email at ecyadacoordinator@ecy.wa.gov. For Washington Relay Service or TTY call 711 or 877-833-6341.  Visit Ecology’s website for more information.​If you speak a non-English language, free language services are available.