The U.S. Department of Defense (DoD) on Aug. 7 restated its opposition to the alignment of the SunZia Southwest transmission project north of the White Sands Missile Range in New Mexico, saying that it could interfere with military operations in the range’s northern extension area and pose an “unacceptable risk to national security.”
In a letter to the principal deputy director of the Bureau of Land Management (BLM), acting deputy under secretary of defense John Conger said it was the DoD’s belief that the final environmental impact statement (EIS) “had not adequately analyzed the significant risk to national security should an above-ground transmission line be constructed” across the range’s northern extension.
An aboveground transmission line would preclude the military’s capability to fully test weapons systems under realistic threat environments, he said.
“No other location exists in the United States where it is possible to conduct flight tests with the footprint requirements these weapons systems present,” Conger said.
The letter went on to cite “substantial new information about the feasibility of burying a segment of the transmission line,” and noted that the applicant’s proposal had been reviewed by a technical working group, which also made recommendations to resolve the DoD’s concerns.
“SunZia has not yet seen the referenced report from the DOD technical working group and will have further comment following that review,” a spokesperson for the project told TransmissionHub Aug. 12, noting that SunZia’s analysis “does not indicate any impact to any mission being conducted in the area of BLM’s preferred alternative, a route previously deemed acceptable by White Sands Missile Range, located 30 miles north of range’s military property.”
Further, the SunZia spokesperson said, undergrounding 35 miles of 500-kV transmission is “neither technically feasible nor economically reasonable.”
In his letter, Conger referenced objections DoD officials had stated in March; however, BLM refined the preferred route published in the final EIS in June, moving the preferred alignment farther north. The refinement was published in the Federal Register June 14. Whether the refined route was the route considered by the DoD working group was not clear from Conger’s letter.
Project officials previously told TransmissionHub that, in addition to adjusting the alignment, developers have offered to reduce the height of the towers along that portion of the line from 135 feet to 90 feet. They have also performed a radar line-of-sight test that shows the concerns about conflict with training missions have been addressed.
Both sides expressed a commitment to work out their differences.
“We remain committed to working with [BLM] … to resolve our serious objection prior to BLM issuing the SunZia record of decision (ROD) and a right of way permit to the applicant,” Conger said. BLM is expected to issue its ROD in September.
SunZia developers are also confident the two sides will be able to find common ground before the ROD is issued.
“We’re still trying to resolve all of the concerns being raised and remain optimistic that we’ll find an acceptable solution,” the spokesperson said.
The 515-mile SunZia project is planned to originate at the new SunZia East substation in New Mexico and head west, with significant portions running parallel to I-25 and the Rio Grande River. The route follows a pipeline corridor north of I-10 in New Mexico and continues into Arizona, where it alternately uses existing pipeline and utility corridors where available before terminating at a new substation in Pinal County near Coolidge, Ariz.
The project is being sponsored by a consortium of five companies. Three of those companies – Southwestern Power Group II/MMR Group, Shell WindEnergy Inc., and Tucson Electric Power – are sponsoring 86% of the project. Salt River Project has a 13% stake and Tri-State Generation and Transmission Association has a 1% interest.