The Boscobel to Lone Rock (Line Y124) Rebuild Project continues to be on schedule for a December 2019 in-service date, American Transmission Company (ATC) told the Public Service Commission of Wisconsin on April 21.
As TransmissionHub reported, the commission, in a September 2016 final decision, granted, subject to conditions, ATC’s application for authority to rebuild about 25 miles of the existing 69-kV transmission line between the existing Boscobel substation in the city of Boscobel, Grant County, and the Lone Rock substation in the town of Buena Vista, Richland County.
Other than rerouting the line in two segments for a total distance of about nine miles, the existing line will be rebuilt within its existing right of way, the commission said in its decision.
The operating voltage of the line will remain at 69 kV, the commission said. ATC proposes to rebuild about 25 miles of the existing 27.6-mile line, the commission said, adding that the company and its predecessor transmission owner have performed maintenance rebuilding on the remaining 2.6 miles of the line during the past 20 to 30 years. On that section of the line, ATC proposes to selectively replace additional facilities following regular maintenance inspections, the commission said.
As part of the proposed project, ATC will install an optical ground wire for information and protection purposes for the entire 27.6-mile length of the line, the commission said. In areas that will be completely rebuilt, the existing wood pole wishbone structures will be replaced by weathering steel monopole structures, the commission said.
Discussing the project’s need, the commission noted that the line was originally built in 1955, and is about 61 years old. The line is in poor physical condition and is reaching the end of its useful life, the commission said.
The company, in its April 21 quarterly progress report for the period Jan. 1 through March 31, told the commission that a biological assessment (BA) of federally listed species was submitted in February. The BA is required as part of the agency consultation between the U.S. Army Corps of Engineers and the U.S. Fish and Wildlife Service, the company said.
An “NR 216 Storm Water” permit application will be submitted when design is sufficiently complete, ATC said.
Detailed design activities for the transmission line portion of the project began, ATC said, noting that detailed design activities for the substation have not started.
ATC said that the approved total project cost is about $32.4m, and that the total project cost through March 31 was about $1.9m.