A draft plan to clean up industrial PCBs in the ailing Spokane River, the state’s most PCB-fouled waterway, is ready for public review.

The Washington Department of Ecology wants to cap an underwater, 3.7-acre sediment zone directly behind Upriver Dam with a layer of coal or sand and also scrape a two-foot-deep layer of PCB-tainted sediments from a smaller area farther east, near Donkey Island. A 30-day public comment period starts this week and runs through April 20.

Ecology’s preferred cleanup plan will cost approximately $2 million, said agency spokeswoman Jani Gilbert.

Ecology, Kaiser Aluminum & Chemical Corp. and Avista Development Inc., a subsidiary of Avista Utilities, forged a legal agreement in 2003 to study PCB sediment contamination from Upriver Dam to the Centennial Trail footbridge in the Spokane Valley.

PCBs from Kaiser’s Trentwood rolling mill and from the Spokane Industrial Park, owned by Avista Development until the mid-1990s, entered the river for decades. The industrial park is now connected to the city’s sewage treatment plant.

Ecology also identified Liberty Lake Sewer District and Inland Empire Paper Co. (a subsidiary of Cowles Publishing Co., which also owns The Spokesman-Review) as other parties contributing to the PCB pollution. They did not participate in the legal agreement with Ecology.

Kaiser and Avista are paying for the cleanup. Under the state’s Model Toxics Control Act, they have the option to sue the other polluters to force them to share in the cleanup costs, but there’s been no word yet of any legal action, Gilbert said.

There’s been no decision yet on any litigation, said Avista spokesman Hugh Imhof.

Last November, Ecology fined Kaiser $40,000 for releasing 143 pounds of PCBs to the river from November 2002 to January 2003 – amounts 1,000 times higher than the usual releases. Kaiser, which is in Chapter 11 bankruptcy proceedings, has appealed the fine to the state’s Pollution Control Hearings Board.

PCBs, or polychlorinated biphenyls, are a group of 209 synthetic chemicals used in transformers and other industrial equipment that were banned in 1979 due to their toxicity and their tendency to accumulate in the bodies of fish. They are a suspected human carcinogen.

Completion of the PCB cleanup plan is “a positive step toward restoring the health of the river,” said Flora Goldstein, Ecology’s toxic cleanup manager in Spokane.

Researchers began to detect PCBs in fish in the Spokane River as early as 1978. In July 2003, a fish advisory issued by the Washington Department of Health and the Spokane Regional Health District warned people not to eat any fish from Upriver Dam to the Idaho border because of PCBs and lead found in fish tissue. Lead and other heavy metals were washed downstream from mining operations in Idaho’s Silver Valley. The PCB clean-up will also remove heavy metals behind the dam, according to Ecology’s proposal.

The PCB cleanup will be discussed at a meeting on March 28 from 7 to 9 p.m. at the Spokane Community College Lair, N. 1810 Greene St. The cleanup plan can be reviewed online at https://www.ecy.wa.gov/programs/tcp/sites/spo_riv/spo_riv.htm