Blaine County Commissioners fear that a 500-kilovolt power transmission line being considered for portions of eastern and south-central Idaho could harm local property values, agricultural uses and the rural character of the region.
On Tuesday, the county commissioners finalized a list of comments they will send to the U.S. Bureau of Land Management regarding the massive powerline proposal. Called the Mountain States Transmission Intertie, the line would stretch from Townsend, Mont., to the Midpoint Substation just south of Shoshone on the east side of U.S. Highway 93.
The 390- to 430-mile transmission project is proposed by NorthWestern Energy, a Sioux Falls, S.D.-based electricity and natural gas utility.
The commissioners' comments are being sent to the BLM just as the agency is set to consider the environmental impacts of the two-state project, which it is required to do by the National Environmental Policy Act. This portion of the BLM assessment is called the scoping process, the period of time when the agency accepts comments that establish the range of issues it will investigate in the environmental impact statement.
"We want to tell the BLM what to look at in the EIS," Blaine County Commissioner Tom Bowman said.
The project has become controversial locally because of one of the routes NorthWestern Energy has considered. Designated as the secondary alternative in the utility's application to the federal government this spring, it would hug the northwest boundary of Craters of the Moon National Monument and Preserve west of Arco, which for now is powerline-free, before passing by private ranchlands to the north of Carey. In the Picabo area, the route would cut across private ranchlands just east of Silver Creek and its renowned trout waters.
From there, the transmission line would head southwest across the high desert, eventually connecting with U.S. Highway 26 about halfway to Shoshone.
NorthWestern Energy's preferred route—which it announced to the support of Carey and Picabo residents in July—would run alongside existing powerlines that pass through the Idaho National Laboratory on their way to the Borah Substation west of Pocatello. From the Borah Substation, the transmission line would head west and end at the Midpoint Substation.
The selection of a preferred alternative by NorthWestern Energy does not entirely kill off the possibility of the northern Carey route. The NEPA process only requires companies to identify possible alternatives, which means the Carey route could still be selected by BLM officials as the preferred route.
Locals hope to convince the BLM that the northern Carey route is a no-go.
Additional concerns highlighted in the commissioners' letter include the possible health effects of having the powerline pass by homes and the possibility of accidents associated with the overhead transmission lines, both from people on the ground and people flying, especially in light aircraft.
Spaced every 1,400 feet, the project's 110- to 130-foot-tall, lattice-steel towers would dominate the skyline if constructed in the sparsely populated Carey area, opponents claim.