The Obama administration has completed a yearslong environmental review of a 360-mile transmission line project across southern New Mexico and Arizona that is expected to promote renewables in the West.
A notice announcing completion of the final environmental impact statement (EIS) for the Southline Transmission Project conducted by the Bureau of Land Management was published in today’s Federal Register but under U.S. EPA’s section. Today’s notice begins a 30-day public review period running through Dec. 7.
The two-part project proposes to build about 240 miles of new double-circuit, 345-kilovolt line beginning in southern New Mexico and upgrade about 120 miles of existing line on the project’s westernmost route, mostly in Arizona.
The new and rebuilt sections of transmission line would be able to carry up to 1,000 megawatts of electricity – some of which is projected to be generated by planned solar power projects – from an existing substation south of Las Cruces, N.M., to a substation near Willcox, Ariz.
The new section of line would run near the Afton Solar Energy Zone (SEZ) in southern New Mexico, which was identified by the Interior Department in 2012 as suitable for commercial-scale solar development. The power line would also pass near areas designated as suitable for various forms of renewables development in Arizona as part of BLM’s Restoration Design Energy Project.
“We’re supportive of the Southline project because we think it will facilitate delivering New Mexico wind and solar power to markets in Arizona and California,” said John Shepard, a senior director of programs for the Tucson, Ariz.-based Sonoran Institute, which has followed the project closely. “That’s especially true given California’s new 50 percent renewable energy requirements. That’s going to be a real financial inducement to make projects like Southline doable.”
A copy of the four-volume final EIS is available online here, on EPA’s National Environmental Policy Act Web page. EPA, which was not involved in the Southline review, publishes EIS notices in the Federal Register each Friday for various federal agencies.
BLM plans to formally publish the final EIS in the Federal Register on Tuesday, said Mark Mackiewicz, a national project manager for the agency who is overseeing the Southline project.
A record of decision approving the $700 million power line is not expected until early next year, he said.
BLM is partnering on the review of the Southline project with the Energy Department’s Western Area Power Administration (WAPA), which is considering paying a portion of the cost for the construction of the project once it passes federal review. No decision has been made on whether the administration “will participate in the ownership of the proposed project,” said Jen Neville, a WAPA spokeswoman.
Mackiewicz said the project represents a significant effort on the part of BLM and WAPA, which owns the existing 115-kilovolt lines set to be upgraded, to site the high-tower transmission line as carefully as possible to avoid impacts to sensitive wildlife species, military operations and valued viewsheds in the region.
The project’s proponent – Southline Transmission LLC, a subsidiary of Dallas-based Hunt Power LP – worked closely with the Arizona Game & Fish Department and other state agencies, counties, business owners and residents on the siting of the project.
A spokesman for Hunt Power said the company will not comment until the final EIS is released next week by BLM.
But Mackiewicz credited the company with being flexible enough to resolve some initial siting concerns, particularly along a playa near Willcox, Ariz., that’s known to have a large concentration of migrating sandhill cranes and other migratory birds.
Working with Arizona Game & Fish, the company has agreed to pay to move a small man-made lake east of the proposed transmission line route in an effort to reduce the potential for bird collisions, he said.
“The game commission approved it, and they’re moving forward with possibly implementing this” mitigation proposal, he said. “That’s one of the cool things about this project.”
Another major siting concern is a section of rebuilt line that would pass near Tumamoc Hill west of downtown Tucson, Ariz., which is an important site for ecological and anthropological research and a national historic landmark.
To address the concern, they will reroute the line away from sensitive areas and through a “gully” that will make the 134-foot-tall transmission towers less visible – a chief concern with residents, Mackiewicz said.
“Our visual people and others think the new line would be less intrusive than the old line it’s replacing,” he said. “It will still be visible, but we’ve done our best to microsite them.”
BLM, WAPA and the project proponents had to work with the Defense Department on some siting issues, too, he said.
A section of the Southline project would cross the U.S. Army Electronic Proving Ground at Fort Huachuca in southern Arizona – the Army’s premier location for testing command, communications, computer and intelligence systems, and equipment, including unmanned vehicles.
The concern is electromagnetic interference from power lines, though Mackiewicz added that modern power lines would cause less interference. He said they agreed to reroute the line closer to existing infrastructure.
“The route is mostly the same, but we kept it further away east of the testing area,” he said.
Click here to read more about the Southline Transmission Project.