Monday, November 10, 2003
Copyright © Las Vegas Review-Journal

'76 uranium mystery still causing concerns

New tests possible at Northern Nevada site

Waste piles from the closed Anaconda Copper Co. mine tower over a road on the outskirts of Yerington in this Jan. 9, 2001, photo. Unlike today's modern mining operations, in which tailings ponds and evaporation ponds are lined with material such as vinyl rubber, some of the ponds at the Anaconda site were unlined and might have allowed leaching of uranium and copper. AP Photo A sign warns against entering the closed Anaconda mine on the outskirts of Yerington in this January 2001 photo. AP Photo

WEED HEIGHTS -- It was a secret at the time, a plan to turn toxic waste into riches.

As demand grew and prices soared for the raw material of nuclear reactor fuel, the Anaconda Copper Co. and Wyoming Mineral Corp. entered an agreement in March 1976 to produce yellowcake uranium from waste piles at a huge open-pit copper mine in Northern Nevada.

The decision to launch the Yerington Uranium Project was based on samples taken from evaporation ponds that showed high levels of radiation, suggesting commercial quantities of uranium had been concentrated along with copper leached from the ore.

But five months later, the project wasn't finding as much uranium in the ponds as anticipated. And company officials didn't know why.

"Should we have found more?" James Brooke, Wyoming Mineral's engineering and production development manager, asked Anaconda's regional geologist in a letter July 26, 1976. "If so, where could it be now? Should we continue to look for it?"

Nearly three decades later, the mystery of the missing uranium is again causing concerns, only this time profits aren't the issue.

Residents in this agricultural community, neighboring tribes and an environmental watchdog group want to know whether the cancer-causing material polluted the wells used for drinking water in the Mason Valley, 55 miles southeast of Reno.

Thirty years later they also are asking, "Where could it be now?"

"It's obvious to me where it is," said Tom Myers, a hydrologist and executive director of the Great Basin Mine Watch, which monitors the mining industry from Reno. "It must have infiltrated through the bottom of their pond. It was probably doing that for 25 years."

Documents found

New concerns about the abandoned 3,500-acre mine site have been on the rise since word spread of the discovery of decades-old documents in archives at the University of Wyoming.

One of the documents recovered by a government contractor in June shows that at least one evaporation pond tested positive for high levels of uranium in the mid-1970s. Another showed tests of monitoring wells on the site in 1984 with uranium at up to 40 times the current legal limits set by the Environmental Protection Agency.

Unlike today's modern mining operations, in which tailings ponds and evaporation ponds are lined with material such as vinyl rubber, some of the ponds at the Anaconda copper mine at Yerington were unlined. The bottom was nothing but dirt.

"This is not proof positive that uranium is still there, but it is proof positive that we should be out testing," Myers said.

Water worries

The irrigated farms and ranches of the Mason Valley are greener than much of Nevada's high desert. At 4,300 feet, onions and alfalfa flourish in fields alongside grazing sheep and horses.

The crops grow between irrigation ditches, some within a few hundred yards of the mine's four-mile-long stretch of waste rock piles and tailings.

As many as 5,000 people drink water from an estimated 100 wells within five miles of the mine site, which had been considered for Superfund status because of its acres of hazardous materials.

Government regulators agree that more testing is needed.

Jim Sickles, a remedial project manager for EPA's regional office in San Francisco, said if there was uranium in the ponds in 1976, "it is probably still there. It may have gotten into the groundwater. It could have migrated off the site. We don't know," he said.

"We think it is a serious concern so we want to move it forward as quickly as we can. It may not be terrible, but it says we can't handle it as business as usual."

Questions raised

Officials for Arco, a former owner of the mine now responsible for the cleanup, agreed only last month to new tests for uranium. They insist the first they'd heard of the possibility of contamination, including the 1984 test documents, was about a year ago when EPA and Bureau of Land Management officials started asking questions.

"I can't say there wasn't a piece of data out there somewhere but it wasn't part of the data we were reviewing for the (cleanup) plans," said Dave McCarthy, an environmental manager for Arco in Butte, Mont.

"There was a perception that there was some attempt to cover up information and that is not true," he said.

Arco has been doing regular testing since the late 1980s for other contaminants, including mercury and arsenic, both on the site and at wells off the property, McCarthy said.

"There is 15 years of data out there that show drinking water in wells has not been affected by mine-related water," he said.

Some residents agree with Arco that the potential dangers are being exaggerated, raising unfounded fears based on old documents.

"I think it would be hard to draw any conclusions based on information from back in 1976. Technology has changed so much the last 25 or 30 years," said Yerington City Manager Dan Newell, who is urging a slower, more measured response.

Earle Dixon, a BLM project manager, agrees the old data is "kind of soft."

"BLM would view it as a little bit suspect and maybe not that reliable," he said, all the more reason to conduct new tests, perhaps as early as next year.