Department of Ecology Toxics Clean Up Program

Description

In 2008, 2011, and 2013, the Department of Ecology (Ecology) and the City of Bothell (City) negotiated three legal agreements called Agreed Orders to perform site investigations on five contaminated City-owned properties (Landing, Riverside, Paint & Decorating, Hertz, and Ultra Cleaners sites) in downtown Bothell. These sites, four of which lie in the pathway of the new Crossroads (SR 522) roadway alignment, are being cleaned up in accordance with the Model Toxics Control Act (MTCA), prior to and during the roadway construction and site redevelopment.

Scope of Work

The scope of work in the Agreed Orders includes completing Remedial Investigations (RI), developing Feasibility Studies (FS), and preparing Draft Cleanup Action Plans (DCAP).  Under the Agreed Orders, the City received Remedial Action Grant (RAG) funding to complete the work. With $3,520,000 in secured RAG funds administered under Ecology’s Toxics Cleanup Program, Ecology will pay for 50% of eligible costs incurred by the City.

Interim Actions

In June 2010, Ecology and the City collaboratively executed amendments to the Agreed Orders to include Interim Actions. Under WAC 173-340-430, an interim action is a remedial action that is technically necessary to reduce a threat to human health or the environment by eliminating or substantially reducing one or more pathways for exposure to a hazardous substance, that corrects a problem that may become substantially worse or cost substantially more to address if the remedial action is delayed, or that is needed to provide for completion of a site hazard assessment, remedial investigation/feasibility study or design of a cleanup action.  An interim action is a partial cleanup that could eventually qualify as a final cleanup under MTCA. 

Four of the sites were cleaned up during the Crossroads roadway construction in 2010, 2013, and 2017. Cleanup consisted of excavating contaminated soils and transporting them for disposal at a licensed facility that handles hazardous materials. The excavations were treated with slurry and oxygenated pellets to remediate the remnant soils and groundwater, followed by backfill with clean material. Due to the type of contaminant at the Ultra Cleaners site, a different treatment approach consisting of bioremediation was implemented at this location. Groundwater at the sites was then monitored quarterly by sampling newly installed monitoring wells for a one year period following the cleanup.