The Washington state Department of Ecology is proposing to enter into a formal agreement with Union Pacific Railroad Co. to study contamination at a former aluminum recycling site at 2317 N. Sullivan, in Spokane Valley.

A month-long public comment period on the proposal ended Sept. 21. Ecology spokeswoman Jani Gilbert says Avista Corp., which owns adjacent property, provided the only comment, urging the department to move quickly on the study.

The pact would require UP to pay for a study at the site. The railroad leased the site to Aluminum Recycling Corp., which operated there from 1979 to 1985.

"The recycler is long gone and bankrupt, and there's no finding them," Gilbert says. Therefore, UP is solely responsible for the cleanup, she says. UP spokesman Tom Lange couldn't be reached for comment.

Processing byproducts containing aluminum, chloride, fluoride, and nitrate remain on nearly three acres of the site, says an Ecology overview. The amount of contaminants present is unknown, but the site has been listed at level two on Ecology's Hazardous Sites List. A ranking of one through five is possible, with one representing the greatest potential threat to human health and the environment.

The study will determine the extent of the pollution, including whether it has reached groundwater in the area, and will suggest methods of cleanup. It also will estimate the cost of the cleanup. A report on the study, which Gilbert says will take about a year, will be released. Then it will take about a year to 18 months to complete the cleanup, or longer if groundwater is involved, Gilbert says.

The site is adjacent to the 512-acre Trentwood rolling mill owned by Kaiser Aluminum & Chemical Corp., which also has undergone extensive cleanup of contaminants from its aluminum production.