BLM seeks comments on new transmission west of Phoenix

The U.S. Bureau of Land Management (BLM) is soliciting public comments on the draft environmental impact statement (EIS)/draft resource management plan amendment (RMPA) it recently issued for a proposed 38-mile transmission line west of Phoenix, Ariz.

Arizona Public Service (APS) is proposing the 500/230-kV Sun Valley to Morgan project from the Morgan substation near Peoria, Ariz., to the planned Sun Valley substation near Buckeye, Ariz. The overhead transmission line would primarily use private, state trust lands and about nine miles of public land managed by the BLM.

The BLM’s charge, according to the draft EIS/draft RMPA, is to respond to APS’s request for a right-of-way (ROW) grant for access across public lands. The BLM is required by the National Environmental Policy Act (NEPA) to assess the impacts when its lands would be affected.

“There are seven miles along [State Route] 74 that require a plan amendment and some other changes in order to accommodate the line in the area north of S.R. 74,” a BLM spokesperson told TransmissionHub Nov. 19, adding that, “two miles on the far west end [of the route] is designated as a transmission corridor, so we have no issue with that.”

The draft EIS/draft RMPA analyzes APS’s proposed action, three alternative routes, and the results of taking no action. The route proposed by APS has been selected as BLM’s preferred action, with some modifications.

According to the document, the double circuit transmission line would largely parallel S.R. 74 along a 200-foot ROW, and would be constructed as two, single circuits at various angle locations along the route. In most instances the project would be constructed on single-pole steel structures, approximately 135 to 195 feet tall, BLM said in the draft EIS/draft RMPA.

“The 500-kV line will be for redundancy of service to protect the area from outages,” the spokesperson said. “APS’s stated need is to provide service on the [230-kV] line for additional development in that area.”

The project’s 500-kV circuit would be designed as a tri-bundled conductor three-phase circuit – nine wires total – and would be installed first, with a proposed in-service date of 2016. The project’s 230-kV circuit would be a single-conductor, three-phase circuit – three wires total – or a twin bundled conductor – six wires total. It would be strung on the same structures in the future when load growth made the expansion necessary. That expansion is expected to be constructed after 2021, an APS spokesperson told TransmissionHub Nov. 19.

The cost estimate for the 500-kV portion of the project is $127m; the total project cost is currently estimated at $180m, the APS spokesperson said.

A 90-day comment period began Nov. 9 when a formal notice of the draft EIS/draft RMPA was published in the Federal Register. The comment period ends Feb. 8, 2013.

APS is a subsidiary of Pinnacle West Capital (NYSE: PNW).