Lyon County’s open pit mine has become the focus of local concern over water quality.

Lyon County’s open pit mine has become the focus of local concern over water quality.

Photo By David Robert

Are contaminates from a local mine a looming threat?
About 50 miles southeast of Reno, after driving through vistas of sagebrush and mineral-rich mountains, a black-and-white road sign appears: “Experience Yerington.” With its population of 2,902, the town’s in the “don’t blink or you’ll miss it” category.

Those who blinked would also miss the giant chasm dug a little beyond the sign. Mounds of dirt streaked gray, white and rust-red ring a former open-pit copper mine deep enough to kill anyone who ventures too close to its edge. Another blink would blot out the houses less than a block from its base.

Yerington had a copper mine on and off from 1918 to 2000. Mining production may have stopped, but its presence is still felt—particularly in concerns of local drinking water contamination.

Recent testing discovered levels of uranium higher than the U.S. Environmental Protection Agency (EPA) standard of 30 parts per million in the private wells mostly north of the site. One of the eight wells that exceeded the standard contained 108 parts per million. To all homeowners whose wells tested higher than 25 ppm, bottled water has been offered by the Nevada Division of Environmental Protection (NDEP) in conjunction with the Atlantic Richfield Co., which purchased the mine from the Anaconda Copper Co. in 1977.

Since Yerington’s groundwater generally flows north, the discovery of higher rates of uranium in residential wells north of the mine site has sparked concerns that the mine’s pump-back system—designed to keep the mine’s groundwater on site—is not fully containing contaminants. However, despite the mine’s being close by and easy to blame, there is no evidence of linkage between the water contaminants and the open pit.

“If the pump-back system was completely effective, you shouldn’t see it in there,” said Jim Sickles, EPA remedial project manager. “Admittedly, that could be [naturally occurring uranium]. We don’t really know. We need to get more information.”

The EPA considered declaring the 3,500-acre mine a Superfund site in 2000, which would make it eligible for federal funding to clean up the contaminants. According to the EPA, elements present naturally in soil, rocks and water, such as uranium, can be concentrated into hazardous amounts by mining and refining processes. These concentrated byproducts of mining can be introduced back into the environment by wind and water if it is not properly contained. Other substances on the site that consistently violate EPA standards include arsenic, cadmium, chromium, copper, lead and nitrates.

But state officials decided to avoid being labeled a Superfund site because it could have harmed property values and scared away businesses. Jim Najima, NDEP bureau chief of corrective actions, said local agencies can do a better job of ensuring cleanup of the site than federal agencies.

“Just because it’s listed as a Superfund site doesn’t necessarily mean that it will receive funding, nor does it dictate that it will get cleaned up to an appropriate level,” he said.

Unlike Superfund sites, which have to compete for federal funding, Najima said Atlantic Richfield has agreed to reimburse the NDEP for its oversight and reclamation efforts.

The state isn’t cleaning the mine alone. Approval from the Bureau of Land Management and the EPA is needed for every major step of the project. Both Najima and Sickles say it can be a cumbersome process.

“The idea of doing this coordinated agreement with the state is new,” Sickles said. “It really hasn’t been done before, so as a result it takes a lot longer than you’d like.”

Since the mine has not been officially linked with the uranium present in the domestic drinking wells, agencies and local residents wonder if the mine that dominates Yerington’s skyline is a looming problem or just a scar from Yerington’s past.

Resident Joyce Ward, who said her well tested above EPA uranium standards, asked, “Is the mine a big threat or just an ugly neighbor? I don’t know. I don’t have the answers yet.”