The Bonneville Power Administration (BPA) is preparing a preliminary environmental assessment (EA) for the proposed rebuild of the Keeler-Forest Grove and Forest Grove-Tillamook 115-kV transmission lines that run between the cities of Hillsboro and Tillamook in Washington and Tillamook Counties, Ore.
“Most of the wood pole structures are at the end of their service life and are physically worn and structurally unsound in places,” BPA said in an August 2012 letter outlining the scope of the project. “Based on the current condition of these lines, we need to replace the wood pole structures and associated structure components to maintain reliable electrical service and to avoid safety risks to the public and transmission line workers.”
No major rebuild work has been done on the Keeler to Tillamook transmission lines since they were built in the late 1950s, BPA said.
The rebuild, which is part of the agency’s ongoing effort to update aging portions of its infrastructure, would include replacement of all wood pole structures over 10 years in age, including cross arms, cross braces, guy wires, anchors, insulator assemblies, switches, and overhead conductor along the lines’ 58 mile route.
In addition, the project would include improving some existing access roads to accommodate construction equipment. New road access would be also be acquired or constructed in areas where access is not currently available.
The project, including design and environmental work, road repairs, transmission line materials, and construction are estimated to cost $17.5m, a BPA spokesperson told TransmissionHub June 3.
Per the procedures outlined in NEPA, BPA will address two alternatives in the preliminary EA: rebuilding the lines, or not rebuilding them and continuing with current operation and maintenance practices. The preliminary EA will describe anticipated impacts to natural and human resources and include mitigation measures that would enable BPA to avoid or minimize impacts, the agency said.
BPA will consider more than a dozen comments it received through its website before the comment period closed on Sept. 24, 2012. It will also consider comments gathered at two public meetings held in September in producing the preliminary EA, which will also be made available for review and comment.
Following an additional comment period, BPA will produce a final EA, which it anticipates issuing this winter. Based on its analysis, BPA will either prepare a finding of no significant impact, decide whether to proceed with the project, or prepare an environmental impact statement if there is the potential for significant environmental impacts.
The agency hopes to award a contract in the spring of 2014 and have work completed in December 2014.