Experts see long-term risks from Colorado mine spill

The toxic waste that gushed last week from a Colorado mine and threatened downstream water supplies in at least three states will continue to be dangerous whenever contaminated sediment gets stirred up from the river bottom, authorities said Wednesday, suggesting there is no easy fix to what could be a long-term public health risk.

[...] the strong dose of arsenic, cadmium, lead and other heavy metals settled out as the wastewater traveled downstream, layering river bottoms with contaminants sure to pose risks in the future.

The U.S. Environmental Protection Agency had pushed for 25 years to grant Superfund status to the partly collapsed Gold King mine and other idled mines leaking heavy metals above the old mining town of Silverton, Colo.