New cleanup method proposed for contaminated Georgetown site

The General Electric Company (GE) plans to change the cleanup method it is using in ongoing efforts to chemically treat contaminated groundwater beneath and near the company’s former location in Seattle’s Georgetown neighborhood.
 
The Washington Department of Ecology is seeking public comment through Sept. 28, 2018, on the change. GE is conducting the cleanup at 220 S. Dawson St. under a 2014 legal agreement (PDF document) with Ecology.
 
GE proposes to inject very small iron particles mixed with organic plant material into the groundwater where they would chemically and biologically react to break down the contaminants. Over the past two years, other treatment methods have not produced the expected results.

Get information and send comments
Ecology seeks comment on:

• A technical memorandum (PDF) for the new groundwater treatment method.

• A State Environmental Policy Act determination of non-significance (PDF) and environmental checklist (PDF) stating that Ecology does not expect the cleanup remedy to harm the environment. 

These documents and other information about the cleanup are available at:

• Ecology’s website.

• Seattle Public Library, NewHolly Branch, 7058 32^nd Ave. S, Seattle

• Ecology’s Northwest Regional Office, 3190 160^th Ave. SE, Bellevue. Call 425-649-7190 for an appointment.

Send comments online or by conventional mail to: Dean Yasuda, Site Manager; Department of Ecology; 3190 160^th Ave. SE; Bellevue, WA 98008-5452
 
Historic solvent releases
GE produced and serviced aircraft parts during the years it occupied the building between 1949 and 1996. Later tenants have since used the building as a warehouse and office building.
 
When GE occupied the building, solvent spills and leaks contaminated underlying soil and groundwater. The main contaminants include solvents used to clean metal parts, as well as fuels and oils.
 
The contaminants have migrated west in the groundwater to at least as far as Utah Avenue South. Some of the solvents below the building release vapors that can move upward through the soil into its workspaces.
 
Under a 2007 agreed order with Ecology, GE installed a system to protect the building’s occupants. The system directs vapors from under the building to a roof vent, where they quickly dissipate to acceptable levels.
 
Next steps
Ecology will review all public comments before deciding whether to accept the proposed new cleanup method.