Wisconsin state regulators, in a Sept. 16 final decision, granted, subject to conditions, American Transmission Company’s (ATC) application for authority to rebuild about 25 miles of the existing 69-kV transmission line, also known as line Y-124, 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 would be rebuilt within its existing right of way (ROW), the state Public Service Commission (PSC) said.
The project has an estimated total cost of about $32.4m, based on an in-service date of 2019, the PSC said.
The operating voltage of the line will remain at 69 kV, the PSC said. ATC proposes to rebuild about 25 miles of the existing 27.6-mile line, the PSC 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 PSC said.
As part of the proposed project, ATC would install an optical ground wire for information and protection purposes for the entire 27.6-mile length of the line, the PSC said. In areas that would be completely rebuilt, the existing wood pole wishbone structures would be replaced by weathering steel monopole structures, the PSC said.
Discussing the project’s need, the PSC 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 PSC said.
The proposed project route is divided into five segments, including Segment 1, which runs from the Boscobel substation northeast for a distance of 6.3 miles to the Blue River Tap.
No significant environmental consequences are associated with the proposed project, and while alternatives to the proposed project have been considered, no other reasonable alternatives to the project exist that could provide adequate service in a more reliable, timely, cost-effective and environmentally responsible manner, the PSC said.
The proposed project will affect waterways and wetlands, and will require permits from the state Department of Natural Resources for construction in waterways and wetlands, construction site erosion control, and storm water handling, the PSC said. In addition, the proposed project will require ATC to obtain permits from, provide notification to, and coordinate with the U.S. Army Corps of Engineers. Furthermore, the proposed project will affect state highways and require permits from the state Department of Transportation, the PSC added.
The approved transmission route may affect historic properties listed with the Wisconsin Historical Society, and its direction will be required to avoid or minimize adverse impacts to archaeological resources.
The general public interest and public convenience and necessity require completion of the proposed project, the PSC added. Completion of the proposed project at the estimated cost will not substantially impair the efficiency of the company’s service, will not provide facilities unreasonably in excess of probable future requirements, and when placed in operation, will not add to the cost of service without proportionately increasing the value or available quantity thereof, the PSC said.
Noting that the proposed project has the potential to impact numerous unique and rare resources found along the project route, the PSC said that the state Department of Natural Resources (DNR) has identified seven required actions during construction of the proposed project resulting from the presence of five listed species. The DNR also identified an additional 102 recommended actions resulting from the presence of 66 additional rare resources, the PSC said, adding that not all of the resources listed in the review have the potential to be impacted by the project. Performing as many recommended actions as possible would avoid or minimize impacts to rare resources in the project corridor, the PSC said.
The PSC also said that while there are no direct impacts expected to the Wisconsin River, impacts to the viewshed of the river, as well as to the avian flight patterns, would occur as a result of the increased height of the overhead conductors. The PSC said that it finds that it is reasonable to require that ATC minimize construction impacts to sensitive habitats to the extent practicable.
Discussing upland forests, the PSC noted that ATC has said that ROW clearing will begin in 2017, and line construction will begin in 2019. The PSC said that ROW clearing during the growing season, as well as more than one year prior to the initiation of other construction activities, could be extremely impactful to resources within the ROW. As such, the PSC said that it is reasonable to require ATC to consider modifying its proposed project schedule to mitigate impacts related to vegetation clearing by scheduling those activities during the winter months when vegetation is dormant.
Among other things, the PSC said that beginning with the quarter ending Dec. 31, 2016, and within 30 days of the end of each quarter thereafter and continuing until the authorized facilities are fully operational, ATC is to submit quarterly progress reports to the PSC that include such information as major construction and environmental milestones, including permits obtained by agencies.
Because ATC will not begin transmission line construction until January 2019, and due to the significant amount of rare resources potentially affected by the proposed project, ATC is to update and submit to DNR its endangered resources review within one year prior to beginning line construction, the PSC said.