The Colville Tribes and the state of Washington won a victory in a pre-trial phase of a lawsuit against Teck Resources for dumping millions of tons of smelter slag into the upper Columbia River. Federal District Court Judge Lonnie Suko dismissed Teck’s “divisibility defense” last week, in which the Canadian company had asked the court to divide liability among a number of yet-to-be identified river polluters, leaving Teck with a very small share. The ruling was significant for the Colville Tribe, said Michael Finley, chairman of the tribe’s business council. If Teck is found responsible for polluting the river at a trial scheduled for September, Finley said Teck will be responsible for paying the cleanup costs. The trial “won’t be consumed with Teck’s efforts to blame others for conditions in the river,” he said. However, U.S. law would still allow Teck to seek contributions from other polluters, he added. Teck operates a smelter in Trail, B.C., just north of the international border. Over the past century, the smelter dumped at least 23 million tons of slag into the river, according to the U.S. Environmental Protection Agency. Teck stopped discharging slag into the river in 1995. Slag is a byproduct of the smelting process, which extracts metals from ore. It contains 25 different compounds, including heavy metals.