Uranium Watch and four other conservation groups have raised objections to the Forest Service’s (USFS) draft approval for expansion, citing violations of the National Environmental Policy Act, Endangered Species Act and other regulations.

Uranium Watch program director Sarah Fields said: "The continued operation of the La Sal Mines Complex will cause increasing emissions of radon gas, a radioactive hazardous air pollutant, into the community.

"The USFS cannot claim that radon emissions only a quarter-mile from the La Sal Elementary School are safe."

The expansion will include drilling 3,800 exploration holes, which will dewater around 50 springs and create surface disturbance of over 200 acres, the groups claim.

The groups added that the wildlife and people will be vulnerable to radiological and heavy metal pollution of groundwater, soil and air due to mining.

Western Mining Action Project attorney Roger Flynn said: "Federal law requires that significant threats to human health and the environment posed by uranium mining be very carefully reviewed.

"The regional office correctly determined that these mines cannot be approved without a much more comprehensive review, including the addition of required protective measures to safeguard the public."