The U.S. Environmental Protection Agency will spend more than $2.5 million to clean uranium contamination on the Navajo and Hopi reservations.

The EPA last week entered into two enforcement actions that will contribute toward cleaning up uranium, its decay products and other contaminants, as well as conducting a comprehensive investigation of the levels of contamination. Neither action, however, includes cleanup efforts in San Juan County.

The closest cleanup site to the Shiprock area tackled by the federal EPA in recent years is near Red Valley, Ariz., said Clancy Tenley, assistant director of the Superfund division in the EPA's San Francisco office.

There, the EPA replaced houses that were built with mine waste.

"Those were homes that were contaminated because they were built with some mine waste incorporated into the mixing sand or concrete," he said. "We found 27 contaminated homes. Of those, 14 were replaced and the others wanted a cash settlement."

A 77-acre former uranium mill site in Shiprock, however, still is in line to be assessed. The site was stabilized in 1986 and radioactive materials were entombed in a three-layer, 8.5-foot-thick structure.

The federal EPA plans to revisit the Shiprock site as part of a five-year plan that began in 2008, Tenley said.

"The one in Shiprock is part of our inventory," he said. "We're doing preliminary assessments of all the mines on the reservation. We just have preliminary results on (the Shiprock mill site). We haven't drawn any conclusions."

The recent, $2.5 million settlement addresses sites the Navajo EPA named as priorities, Tenley said. Calls Friday to the Navajo EPA were not returned.

In one settlement, Rio Algom Mining, a subsidiary of BHP Billiton, has agreed to control releases of radium, a decay product of uranium, from the Quivira Mine Site, near Gallup. Rio Algom in the next few weeks will pave a road historically used for hauling waste, minimizing the spread of low-level contaminated dust, Tenley said.

The company plans to minimize erosion from the site and repair fencing to prevent human and animal exposure to a large waste pile. The Navajo Nation's Environmental Protection Agency will work with federal EPA to oversee and evaluate the work.

"We consider this a good first step in making Rio Algom accept responsibility for its past mining practices," Stephen Etsitty, executive

director of the Navajo EPA said in a prepared statement.

The company also will conduct a comprehensive investigation of the levels of contamination at the site. The total cost for this work is estimated to be approximately $1 million.

"The detailed assessment will tell us how much is contaminated, what the risk is and what needs to be done to contain the risk," Tenley said. "The mine is in close proximity to several houses, and it has been a high priority for the Navajo Nation government for several years."

In a second settlement, Bureau of Indian Affairs will begin a comprehensive investigation of the levels of uranium and other contaminants in the waste, soils and ground water at the Tuba City Dump Site, Near Tuba City, Ariz.

The Tuba City Dump Site covers about 30 acres and is located on parts of the Hopi and Navajo reservations, about four miles from a former uranium mill. In 1998, the BIA closed and stabilized the site.

Under the agreement reached this week, the BIA will complete the assessment and evaluate cleanup options for soil, ground water and waste.

To date, the BIA has spent more than $4.5 million at this site. It will spend an additional $1.5 million to complete the investigation and evaluate the feasibility of additional cleanup actions.

"The purpose of our work here in the next two years is to finish assessing it, then figure out feasible options," Tenley said. "The options are to

treat contaminated ground water, remove a portion of the dump if contaminants were excessively high, or remove everything from the dump."

Between 1944 and 1986, nearly 4 million tons of uranium ore was extracted from Navajo lands, according to information from the federal EPA.

The mines are closed, but contamination remains from more than 500 abandoned mines, homes built with contaminated mine waste and contaminated water wells.

Potential health effects from abandoned uranium mines include lung cancer from inhalation of radioactive particles, as well as bone cancer and impaired kidney function from exposure to radionuclides in drinking water.

"Uranium mining has left a toxic legacy, and we are working as partners with the Navajo Nation, the Hopi tribe and other federal agencies to clean up contaminated homes, mines and water supplies," Jared Blumenfeld, regional administrator for EPA's Pacific Southwest Region, said in a prepared statement.

This email address is being protected from spambots. You need JavaScript enabled to view it.