Water samples track mining waste

Officials from the U.S. Environmental Protection Agency collected water samples from the Coeur d’Alene River over the past two days to analyze how flooding transports mining waste.

Lead, arsenic and other heavy metals get carried downstream during high water events, said Ed Moreen, an EPA program manager. The sampling will build on earlier work to help scientists understand how pollution gets distributed in the Coeur d’Alene basin, he said.

EPA officials were also monitoring the East Mission Flats Repository, which opened in 2009. The repository near Cataldo, Idaho, accepts contaminated soil from Superfund cleanup projects.

The repository’s location in the Coeur d’Alene River’s flood plain was vigorously opposed by the Silver Valley Community Resource Center, whose members raised concerns again Tuesday. The federal government shouldn’t put polluted soil in an unlined repository that floods regularly, said Terry Smith, a Silver Valley resident.

But EPA’s Moreen said the repository was operating as designed. The floodwaters enter the repository through culverts. The water slows down in the repository, allowing contaminated soil to drop out of the water, Moreen explained. It’s actually cleaner when it flows back into the river, he said.

Every three months, EPA tests the groundwater at the repository for contaminants, he said.

Becky Kramer