Oily sheen detected on Spokane River near Millwood; tests underway

An unidentified oily sheen was reported on the Spokane River and observed in the Millwood area Tuesday by officials with the state Department of Ecology, according to an agency spokesperson.

Officials initially located little to no sheen along the river as of Wednesday afternoon. However, Avista Operators reported Wednesday evening that the sheen was observed downriver at Upper Falls Dam, Monroe Street Dam and the Nine Mile Dam and have deployed absorbents to try to capture the substance. The source of the pollution has not been determined.

Stephanie May, spokesperson for the Department of Ecology’s Eastern Region, said that a 20-yard-wide sheen had been seen Tuesday a few blocks downriver of the North Argonne Road bridge, which appeared to have originated somewhere upstream. The substance had no detectable smell, as would be expected from a gasoline or oil spill, and also did not adhere to an absorbent material.

A spill response team with the Department of Ecology responded Wednesday afternoon, finding no sheen between the Argonne bridge and the Inland Empire Paper Company to the east, and little to no sheen near where it was detected Tuesday. 

It’s not immediately clear what the pollution was. A sample from the sheen was taken and spot testing conducted in the surrounding area, results from which will likely be forthcoming, May added.