Precision Engineering Inc

Updated May 2022

Formal cleanup in investigation phase

Phase 1 of sampling for the remedial investigation concluded in April 2022.  Soil and groundwater samples were collected throughout the property.  It will take few months to get the samples analyzed and the data checked for quality assurance.  Then Ecology will review the results and decide where additional data are needed for the remedial investigation report.


Why this cleanup matters 

This site is part of Ecology’s Lower Duwamish Waterway source control efforts, because it may be contributing pollution the Lower Duwamish Waterway (LDW) Superfund Site. The 5-mile stretch of the Duwamish River that flows north into Elliot Bay was added to the Superfund National Priorities List by the U.S. Environmental Protection Agency (EPA) in 2001.

The sediments (mud) in the river contain a wide range of contaminants due to decades of industrial activity and runoff from urban areas. EPA is leading efforts to clean up the river
sediments.

Ecology is leading efforts to control sources of contamination from the surrounding land area. The long-term goal is to minimize recontamination of the river sediment and restore water quality in the river. 

The Precision Engineering Inc. Site is one of several sites that will be cleaned up as part of Ecology’s Source Control Strategy – controlling sources of pollution to the river. Contaminants in the soil and groundwater around the river pose a risk to human health and the environment. They can also find their way into the river through storm runoff and other pathways. For more information, visit our Source Control page.

Site Location

The Site is associated with the property (Property) at 1231 S Director Street, Seattle, in unincorporated King County near the municipal boundary between the cities of Seattle and Tukwila. The property is shown on the figure above.  Adjacent properties are developed with residences to the north and northwest and a highway US-99/West Marginal Way cloverleaf interchange to the south. 




Site History

Precision Engineering operated at the Property from 1968 through 2005.  Activities included
grinding and polishing, honing, hard-chrome plating, milling, welding, and other flame and arc-applied metal coatings. Precision Engineering’s work involved the use of a number of chemicals, particularly chromic acid for plating and trichloroethene (TCE) as a solvent. A number of chromic acid plating tanks were located in the former chrome shop, as were tanks containing hydrochloric acid, sodium carbonate, and sodium hydroxide. 


 Contamination 

Initial contaminants of concern identified for this Site include:

•oil and diesel range organics (ORO, DRO)

•trichloroethylene (TCE)

•chromium (Cr III, Cr VI)  


Previous Investigation and Cleanup Work

Remedial action begin in 1990. Initially, a limited amount of highly-contaminated soil was removed from beneath the facility floor and disposed of off-Property. In 1992 four tanks were removed from the Site and additional contaminated concrete and soil was excavated and removed.  Soil samples from the excavation sidewalls indicated that mobile chromium (hexavalent chromium) concentrations remained elevated.  Multiple investigations of the nature and extent of contamination were then completed at the Site, with one additional excavation in 2007 and 2008.  This action involved the removal of 100 cubic yards of metals-contaminated soil from the drainage ditch at the south edge of the Property. Most recently in 2020, actions were taken within the building at the Property to reduce TCE levels in indoor air. These actions included sealing an open sump and cracks in the concrete floor.