The Arizona Court of Appeals ruled Tuesday that the state Department of Environmental Quality illegally issued a Clean Water Act permit for the proposed Resolution Copper Mine, which is being opposed by the San Carlos Apache Tribe.
The decision overturns a Maricopa County Superior Court ruling and orders ADEQ to restart the permit process.
San Carlos Apache officials say the mine will destroy Oak Flat, a sacred tribal religious site on the Tonto National Forest.
Meanwhile, a group called Apache Stronghold, which is authorized by the San Carlos Apache tribe to protect Oak Flat, said the 9th U.S. Circuit Court of Appeals will rehear the case in front of a full panel of 11 judges.
The court previously ruled that the federal government could give Oak Flat to a foreign-owned mining company that wants to construct a massive underground copper mine in Superior, about 70 miles (112 kilometers) east of Phoenix.
Resolution Copper company officials say the mine could produce up to 40 billion pounds of copper over 40 years, making it the largest copper mine in North America.
The state appeals court ruled that ADEQ improperly issued an Arizona Pollution Discharge Elimination Permit to Resolution Copper before it set pollution limits on what Resolution Copper could release into Queen Creek.
“We intend to keep fighting on all legal fronts to stop Resolution from destroying our sacred sites and inflicting environmental destruction across a vast area of Tonto National Forest,” San Carlos Apache Chairman Terry Rambler said in a statement.
“Resolution Copper is aware of and reviewing the court of appeal’s decision," said company spokesman Tyson Nansel. "While Resolution Copper has applied to renew its discharge permit, it does not discharge into the Queen Creek wash.
Treated water is sent to farmers for beneficial use near San Tan Valley, reducing groundwater pumping in the area.”