PHOENIX — The operators of a proposed copper mine in Florence want a federal judge to void a new town law that would effectively thwart the project.

Attorneys for Curis Resources contend the ordinance limiting how much sulfuric acid anyone can have or use is aimed not at public safety, as town officials claim, but solely to make it impossible for the company to do the proposed leaching project. That makes it a special law which is illegal under the Arizona Constitution.

The company also contends the town lacks the authority to approve such a restriction. And it says the fact the town exempted farming operations from the limits shows that the ordinance is not about public safety but only about the mine.

But Deputy Town Manager Jess Kundson said city council members who approved the law in August were acting within their legal rights under state law. And while he acknowledged the action came as Curis is attempting to get the required environmental permits for the controversial mine, Knudson said there is nothing discriminatory about the measure.

"It also applies to all businesses, existing and future,'' he said.

Hanging in the balance could be whether Curis gets to operate the project on the 1,342 acres it controls, including 160 acres of state land.

The project involves a process known as “in-situ” mining, where a solution of acid is pumped into the ground and dissolves the copper. The liquid is then pumped back out, with the copper removed.

Plans are to operate the system for close to 20 years.

Opposition from the town, the owner of the water company and nearby landowners did not block the state Department of Environmental Quality from issuing a temporary permit to Curis to start testing the procedure.

Read the rest of the story in Thursday's Star.