In the present Comprehensive Environmental Response, Compensation and Liability Act (CERCL A) lawsuit, the Confederated Tribes of the Colville Reservation sued defendant in 2004 to recover costs associated with cleaning up environmental contamination in Washington allegedly caused by a Canadian mining companys disposal of slag and liquid effluent into the Columbia River from its mining facility in Canada. Shortly thereafter, the state intervened as a plaintiff. According to plaintiffs evidence, before mid-1995, the facility that defendant owned from 1906 to mid-1996 generated and discharged into the Columbia River certain hazardous substances including slag, as a solid form and in liquid waste, arsenic, cadmium, copper, mercury, lead, and zinc. The river carried the slag and liquid waste downstream, resulting in disposal into waters of the United States, according to the complaint. Defendant argued that the harm caused is divisible and that it is liable only for the contamination proven to be traceable to the defendant by plaintiffs.
Rejecting the companys argument, the court held that it had not proven that the environmental damage could be divided to allow for apportionment of liability and that defendant, and not the plaintiffs, had the burden of proving divisibility. The court also ruled that defendants potential liability does not arise from its disposal of slag in the river, but from actual or threatened releases of hazardous substances from the slag or effluent after it came to rest in the “facility,” defined as the upper Columbia River site. A bench trial is scheduled for September 2012 to determine whether defendant is responsible for the contamination.