Defunct uranium mine contaminating groundwater near reservoir

A defunct uranium mine in Jefferson County is contaminating groundwater near a reservoir, but government regulators and mine executives have yet to settle on a plan for cleanup. Uranium concentrations in groundwater 30 feet beneath the brim of the Schwartzwalder Mine exceed the human health standard for uranium by more than 1,000 times, according to state records reviewed Thursday. Unhealthy concentrations also were detected in Ralston Creek, which eventually enters Denver Water's Ralston Reservoir. The reservoir supplies water to Denver and Arvada. Denver Water managers say no uranium contamination has entered the drinking-water supply. State officials said they want the mine's owner–Greenwood Village- based Cotter Corp., a subsidiary of General Atomics–to submit by Monday a plan for dealing with the contamination at the mine. Colorado mining regulators warned Cotter in July "that water quality degradation at the Schwartz- walder Mine is critical and may be approaching conditions requiring emergency response." Three months later, state officials rejected an initial Cotter protection plan as inadequate, declaring "a potential hazard to human health, property and the environment."