The state Water Quality Appeals Board has upheld Rosemont Copper Co.'s state-issued groundwater permit.
The board voted 2-1 this week to allow the permit issued by the Arizona Department of Environmental Quality.
Challengers to the permit's issuance included Save the Scenic Santa Ritas, an organization that argued the original permit was granted without a thorough review.
“We’ve got over a million people in Pima County that are depending on ADEQ for their safety on this issue to keep us with clean air and clean water, and we feel like they’re not doing their job," said Gregory Shinsky, a board member of Save the Scenic Santa Ritas.
The state issues permits to assure air and water quality, and the Water Quality Appeals Board's decision this week clears the way for a lawsuit on the permit, although Shinsky said his group has not yet decided whether to take the case to court.
Arizona Public Media was unable to reach Rosemont officials on the decision, but Kathy Arnold, a Rosemont vice president who oversees government regulation, previously said the permit was issued after appropriate review.
The permit allows the company to start building water ponds at the site of the proposed copper mine in the Santa Rita mountains, Arnold has said.