FLAGSTAFF, Ariz. (AP) — Arizona environmental officials have approved rules setting stricter standards for uranium mine dust, but conservation groups say the measures don't go far enough.
The Arizona Department of Environmental Quality stopped the re-permitting process last year after learning that uranium concentrations in the soil near a mine tested unusually high twice in a row, The Arizona Daily Sun (http://bit.ly/2dCIa5Q ) reported.
The soil contained two to three times the normal level of uranium, but it was at a minute concentration compared to that found in uranium ore, according to scientists with the U.S. Geological Survey.
New air quality permits recently issued to three uranium mines near the Grand Canyon allow owners to stockpile up to 26 million pounds of mined ore to a height of 20 feet without a covering, although the radioactive ore must be watered to control dust.
The water must be discharged into a basin with an impervious bottom to prevent it from reaching an aquifer.
The permits also require annual testing and stipulate that truck loading activities must stop if the wind speed is above 25 mph.
Conservationists had hoped for a denial of the air quality permits. They say there's no safe level of uranium mining in the Grand Canyon watershed that would protect the Colorado River and other water sources nearby.
Information from: Arizona Daily Sun, http://www.azdailysun.com/