An environmental assessment of American Transmission Company’s (ATC) Riverside Energy Transmission Line Project recommended that the project has no significant impact, that the environmental review is complete, and that preparation of an environmental impact statement is not necessary.
The assessment, which was prepared by an environmental analysis and review specialist with the Public Service Commission of Wisconsin, was received by the commission on Nov. 13, according to the commission’s website.
As noted in the assessment, ATC proposes to build a new 345-kV substation (Kittyhawk), and a new loop-in, loop-out 345-kV double-circuit line that would tap into Line W10 (the loop-out would have the designation of Line W17); as well as upgrade protective relay packages at the Paddock and Rockdale substations and protective relay settings at the Rock River and Townline Road substations.
ATC’s proposed project would connect the new Riverside generation facility to the transmission system.
Discussing the purpose and need of the project, the assessment added that Wisconsin Power and Light (WP&L) submitted a generator-transmission (G-T) interconnection request to the Midcontinent ISO (MISO) for the MISO February 2015 Definitive Planning Phase (DPP) cycle. WP&L demonstrated the need for the new generation known as the Riverside West Project (formerly known as the Riverside Energy Center Expansion Project) in a separate certificate of public convenience and necessity application with the commission, which the commission approved in May 2016. ATC’s proposed project would connect the new Riverside generation facility to the transmission system, the assessment added.
ATC has identified two transmission route alternatives – Route 1 and Route 2 – that pass through the town of Beloit in Rock County, Wis. The assessment also noted that ATC proposes to build these facilities with an in-service date of April 2019:
- Transmission line new construction: A new loop-in, loop-out 345-kV double-circuit line would tap into Line W10, creating two new circuits. Line W17 would run from the Paddock substation to the new Kittyhawk substation. Line W10 would run from the new Kittyhawk substation to the Rockdale substation
- Substation new construction: The new Kittyhawk substation would be arranged in a 345-kV five-position breaker-and-a-half bus configuration with three generation positions and two line positions, capable of future expansion to eight 345-kV positions and a 138-kV eight-position breaker-and-a-half yard with two 345/138-kV autotransformers
- Other substation work: ATC would upgrade relay packages at the Paddock and Rockdale substations, and perform relay improvements at the Rock River and Townline Road substations
The Kittyhawk substation would be located on South Walters Road in Beloit, the assessment noted, adding that while the substation property is owned by WP&L, the substation would be operated by ATC. The substation is located on a 30-acre site with a proposed fenced-in area of 6.2 acres.
The Rockdale substation is located on Koshkonong Road in the village of Rockdale, Dane County, the assessment added, noting that the substation is owned and operated by ATC. No additional property or fence expansion would be needed for that work.
The Paddock substation is located on Paddock Road in Beloit, and it is owned and operated by ATC. The assessment also noted that no additional property or fence expansion would be needed for that work.
Route 1, which ATC calls the preferred route, is 4.2 miles long, and heads south to the edge of the Kittyhawk substation site, before turning west to follow a field edge to Duggan Road (Segment C). The assessment added that the route then turns south to follow Duggan Road for about a quarter mile before it turns west to follow a tree line west to where it crosses Route 2. The route then continues west, proceeding cross country for about three miles to join 345-kV transmission line W10 (Segments C, D, and F).
The assessment added that Route 2 is 4.5 miles long, and heads west from the proposed Kittyhawk substation site, crossing agricultural fields before it reaches Duggan Road (Segment B1). West of Duggan Road, the route parallels an existing 138-kV transmission line (Segment B2), before turning to head south (Segments B3 and E), following field edges, for about 0.6 mile, crossing Route 1. The route then turns west, proceeding mostly cross country for about three miles to join 345-kV transmission line W10 (Segments E and G), the assessment added, noting that the westernmost quarter mile of Segment G is adjacent to Finley Road.
ATC estimates the cost of the proposed project to be $40.9m for Route 1 and $42.3m for Route 2. Of that total, the assessment added, about $22.1m would be for transmission line work for Route 1, and about $23.4m for Route 2; substation work for either route would cost about $17.2m.
The assessment noted that the primary land use in the project area is agricultural and rural residential.
Discussing environmental considerations, the assessment noted that Route 1 would cross five wetlands, totaling 0.1 acres, and that Route 1 and Route 2 would cross mapped tributaries of the Rock River. None of the mapped waterways are identified by DNR as Areas of Special Natural Resource Interest.
The assessment added that Route 1 would require the clearing of about 11.4 acres of upland woodland, while Route 2 would require the clearing of about 11.2 acres of upland woodland.
There is one state-endangered reptile that may be present in areas of suitable habitat along Route 1, the assessment said. Also, there are seven rare plant species that may have suitable habitat present along that route. The assessment further noted that there is one state-threatened fish species that may be present within the streams that cross that route.
Two homes are between 150 feet and 300 feet from the centerline of Route 1, while five homes are between 150 feet and 300 feet from the centerline of Route 2, the assessment said.
The transmission line poles, ranging from 90 to 160 feet tall, could be visible for long distances, the assessment said, adding that the rolling nature of the topography and vegetation would screen distant views of the line in many locations.
Substation construction at the Kittyhawk substation site would permanently convert 6.2 acres of cropland owned by WP&L to non-agricultural use. Among other things, the assessment also said that while the construction of the Ackley substation would result in a loss of productive cropland and have some effects on a nearby residential property, it is unlikely that significant effects on the human environment would occur as a result of the project.