An energy company based in Sioux City, S.D., that is looking to build a major power transmission line between southwestern Montana and southeastern Idaho has identified two corridors through Blaine County as possible routes for the $800 million project.
It is extremely early in the process, and any project ultimately approved will have to be approved under an environmental impact statement under the National Environmental Policy Act. That is a lengthy and thorough process that has not yet even begun.
But the potential routes are real, and the company explained them to the Blaine County Commission Tuesday afternoon.
Locally, the routes identified by energy giant Northwestern Energy for the 350- to 390-mile-long transmission line include two alternative paths between the Idaho National Laboratory near Arco and the community of Shoshone. One of the options identified by Northwestern Energy would route the 500-kilovolt transmission line across the high desert sagebrush lands to the east and south of the 750,000-acre Craters of the Moon National Monument and Preserve.
That section would see 20 to 25 miles of power line through southern Blaine County.
The other possible route identified, and the one that may end up being the most controversial for the public and local officials alike, would see the massive power line hug the monument's northwest boundary between Arco and Carey. From Carey, the transmission line would head southwest along U.S. Highway 26 all the way to Shoshone. That section would see 30-35 miles of power line through southern Blaine County.
An informational pamphlet provided by Northwestern Energy states that the primary purpose of the proposed transmission line would be to meet requests by energy companies for additional power transmission capability and relieve constraints on the high-voltage transmission system in the region. Company representatives say economic growth has created a significant need for improved power transmission between southwestern Montana and southeastern Idaho.
The proposed transmission line would likely begin somewhere near Townsend, Mont., and end near Idaho Power Co.'s Midpoint Substation near Shoshone, or near the company's Borah Substation near American Falls.
Under the energy company's proposal, the transmission line would be built with a combination of 110- to 130-foot-tall lattice steel towers separated from each other by an average distance of 1,500 feet. An approximately 220-feet-wide right-of-way across public and private lands would be required should the towers be built.
Northwestern Energy briefed the Blaine County Commission about the power line and the dozens of potential routes, two of which might travel through Blaine County. They said the utility is looking at a number of alternative routes totaling 1,200 miles, a portion of which will be included in its final preferred route.
Tom Pankratz, Northwestern Energy's project manager for what is being called the Mountain States Transmission Intertie, said his company will consider comments from appropriate federal land management agencies, local county and state government officials and the public in deciding which route the line should take. Pankratz stressed that it is early in his company's consideration of possible routes.
"We are going to get it whittled down to one preferred route," he said.
Pankratz said that under the best-case scenario, Northwestern Energy would like to begin construction on the project in 2010 and complete it sometime in 2013.
Asked if the proposed routes already have existing transmission lines in place that the new line could parallel, he said all but the Arco to Carey route have lines in place. No major power transmission lines exist along the hilly northwestern boundary of Craters of the Moon National Monument and Preserve, he said.
This revelation seemed to trouble commissioners Larry Schoen and Sarah Michael, the only members of the commission present Tuesday.
The route along the northwest boundary of Craters of the Moon would place the line in "one of the most scenic highways in Idaho," Schoen said.
He said that Northwestern Energy needs to consider the concerns of Blaine County residents when considering sites for the line.
"Those are pretty big impacts you're talking about," Schoen said.
Along with Carey Mayor Rick Baird, the commissioners said additional public involvement in the process is needed.
"I think we want to be involved early on in this process," Michael said.
Pankratz and others with Northwestern Energy promised to hold at least one meeting in Carey on the issue sometime in January or February 2008.
"It looks like it's going to go right over the top of Carey," Baird said of the Arco to Carey route.
Express graphic by Gavin McNeil
A proposal by Sioux City, S.D., energy company Northwestern Energy could route a major 500-kilovolt power transmission line through portions of Blaine County. Two of the separate routes being considered, shown on the map above as Proposed Line A and Proposed Line B, created a stir at a meeting of the Blaine County Commission Tuesday.
