Starting this week, the Oregon Department of Environmental Quality will begin overseeing the clean up of the last significant legacy contamination in the downtown reach of the Willamette River.
NW Natural will be removing contaminated sediment at the former Portland Gas Manufacturing. This work will address historical contamination resulting from gas manufacturing operations along the west bank of the river from the mid-1800s to early 1900s.
When it was operating, Portland Gas Manufacturing produced manufactured gas from coal, carbureted water and oil to fuel the first street lamps in downtown Portland.
In accordance with the 2017 cleanup plan, officially called the Record of Decision, cleanup activities will include removal of some contaminated sediment, capping with clean sand and gravel, and enhanced natural recovery. Activated carbon will be added to a portion of the cap to increase effectiveness.
The barges will take excavated sediment to landfills for disposal. Work will be completed using barges and small boats in an area between the Steel and Burnside Bridges, offshore of Tom McCall Waterfront Park.
“Access to the work area will be limited during cleanup, including navigational restrictions for recreational boaters and other river users. A portion of the seawall walking path adjacent to the work area will be closed. Work will take place starting in early July and likely extend through October,” said the Oregon Department of Environmental Quality.