The Environmental Protection Agency has released a draft Human Health Risk Assessment for the upper Columbia River, and will accept public comments on it through July 24.

The assessment follows EPA's study of contamination in the Columbia River from the U.S.-Canada border to Grand Coulee Dam, including surrounding upland areas. Past studies have shown increased levels of heavy metals including arsenic, lead, cadmium, copper, mercury and zinc.

Colville Confederated Tribes initially asked EPA to assess contamination in the upper Columbia River in 1999, expressing concerns about people's health due to contamination from mining operations in British Columbia.

The tribe later sued Teck Metals—formerly Teck Cominco—for dumping waste from its lead and zinc smelter into the river just north of the U.S. border, in Trail, B.C. Two Colville tribal members initially filed the lawsuit in U.S. District Court for the Eastern District of Washington in Spokane, which ruled U.S. laws can be used to hold a foreign company liable when pollution ends up in the U.S. (Pakootas et al. v. Teck Cominco Metals et al). The court ordered Teck to pay the tribe for its scientific investigations and legal costs.

EPA is now responsible for enforcing the judgment, and beginning cleanup and restoration of the upper Columbia, especially of Lake Roosevelt, where metals and waste accumulated behind Grand Coulee Dam.

In 2001, the EPA collected samples of river sediment and determined a more detailed investigation was needed to evaluate risks to human health.

In 2006, Teck American signed an agreement with EPA to pay for a remedial investigation and feasibility study. The draft Human Health Risk Assessment is part of that ongoing study. The assessment evaluates exposures to chemicals for residents, outdoor workers, recreational visitors, and Colville and Spokane tribal members.

The agency will also host webinars on June 10 and July 15 to discuss results of the assessment and listen to public input.

K.C. Mehaffey covers fish issues for Clearing Up, and is editor of the NW Fishletter. She joined the NewsData writing team in February 2018. From lawsuits to scientific studies, she is enjoying the deep dive into the Columbia Basin's many fish topics.