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Southline Transmission Project Achieves Two Key Milestones

Nov. 13, 2015
The Southline Transmission Project is composed of two segments.

The Southline Transmission Project has recently achieved two crucial regulatory milestones, clearing the way to begin an open solicitation process for the project's transmission capacity.

On Sept. 17, 2015, the Federal Energy Regulatory Commission granted a Petition for Declaratory Order, which was jointly filed in May 2015 by two entities related to the Project – Southline Transmission, L.L.C., and SU FERC, L.L.C. Specifically, the PDO granted SU FERC's request for negotiated rate authority and approved its proposed open solicitation process (

On Nov. 6, 2015, the Bureau of Land Management and Western Area Power Administration jointly issued a Final Environmental Impact Statement for the Project. This document includes the agencies' response to substantive comments on the draft EIS, describes the agencies' preferred alternative, details the anticipated effects of the project and provides the basis for the agencies to issue their final Records of Decision. The FEIS is available on the BLM project website:   

Now that these two milestones have been achieved, SU FERC will soon provide broad notice to all potential and interested customers and will solicit interest in the project's bidirectional transmission capacity in southern New Mexico and southern Arizona. This solicitation will occur in late 2015 or early 2016.

"FERC's granting of the PDO and Western's and BLM's issuance of the FEIS represent major achievements for the Southline Transmission Project," said Hunter Hunt, president of Hunt Power, which is the parent company of Southline Transmission, LLC. "Achieving these milestones is a testament to the creativity and hard work of all involved, and truly provides a model for maximizing infrastructure benefits while minimizing environmental impacts. We are excited for the project to have made these important steps and look forward to delivering much-needed transmission capacity to the southwest region in the next few years."

The Southline Transmission Project is composed of two segments. The first segment will be a new 240-mile double-circuit 345-kV line connecting the Afton substation south of Las Cruces, New Mexico, to the Apache substation south of Willcox, Arizona. The second segment will be an upgrade and rebuild of Western's existing 115-kV transmission lines between the Apache substation and the Saguaro substation, which is north of Tucson, Arizona; this segment will consist of 120 miles of new double-circuit 230-kV lines.

Southline will interconnect with up to 14 existing substation locations and include development of a potential new substation in Luna County, New Mexico.

Upon receiving all required permits and approvals, Southline is planning to begin construction in 2016, with transmission operations beginning in 2018.

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