Arizona regulators approve controversial line; add conditions

The Arizona Corporation Commission (ACC) on May 23 unanimously voted to approve conditionally a certificate of environmental compatibility (CEC) for a proposed power line to feed the proposed Rosemont copper mine in the Santa Rita mountains near Tucson (Docket No. L-00000C-11-0400-00164). 

The 5-0 vote followed several hours of last-minute, closed-door negotiations between the parties involved, including Rosemont Mining, Tucson Electric Power (TEP), and other interested parties, during which “about a dozen settlement amendments were proposed,” a paralegal with the ACC told TransmissionHub on May 25.

While not all amendments were approved, the mining company will be required to obtain five additional permits related to the construction of the copper mine before construction can begin on the transmission line, according to the ACC.

Rosemont Copper will pay the construction, operation, and maintenance costs of the line, which will be built and owned by TEP.

From their perspective, TEP officials don’t regard the additional conditions as much of a change. “We had already offered that we wouldn’t begin line construction until the [U.S.] Forest Service issued its record of decision,” a Tucson Electric Power spokesperson told TransmissionHub on May 25. However, the utility now faces additional requirements before line construction can begin.

Rosemont Copper will be required to establish a funding mechanism that would allow TEP to remove the line at Rosemont’s expense if the project is cancelled or the mine were ever to be abandoned.

Other additional conditions require approval of a clean water act permit by both the U.S. Army Corps of Engineers and the Arizona Department of Environmental Quality, and an air-quality protection permit from the state of Arizona. Further, the state land department, which currently owns the right-of-way, must transfer the title to TEP.

Language addressing the issues agreed to during settlement negotiations must be added to the final order, which must then be signed by the commissioners. The final, signed order is expected to be issued during the week following Memorial Day.

“The ACC decision is another huge step forward for Rosemont,” Kathy Arnold, Rosemont Copper vice president of environmental and regulatory affairs said in a prepared statement. “We now have approval to bring electricity to operate the mine.”

Rosemont Copper has already made significant progress toward obtaining the necessary approvals. “Six of the eight [approvals needed] are already complete or nearing completion,” a spokesperson for the company told TransmissionHub on May 25.

“In addition to the approval of the CEC, we are equally pleased that the decision is final and there be no more hearings on this issue,” Arnold added.

TEP is a primary subsidiary of UniSource Energy Corporation (NYSE: UNS).