Written comment on the final environmental impact statement (EIS) for the Cardinal-Hickory Creek Transmission Line project will be accepted until June 28, according to the final EIS that was prepared jointly by the Public Service Commission of Wisconsin and the Wisconsin Department of Natural Resources (DNR).
The final EIS will be considered by the commission when it makes its final decision on the project, the document noted, adding that the commission decision is expected in September.
The commission decision on the merits of the project will be based on the record of a public hearing that will be held beginning June 17, the final EIS said. The document also noted that hearing sessions in the project area for members of the public will be held on June 25 in Lancaster, Wis.; June 26 in Madison, Wis.; and June 27 in Dodgeville, Wis.
As noted in the final EIS, ATC, ITC Midwest LLC, and Dairyland Power Cooperative (DPC) in April 2018 filed an application with the commission for approval to build the Cardinal-Hickory Creek Transmission Line Project, which involves installing a new 345-kV line from the Hickory Creek substation in Dubuque County, Iowa, to the Cardinal substation in Dane County, Wis. If approved, ATC would own 45.5% of the project, ITC would own 45.5%, and DPC would own 9%.
Depending on approvals and possible route alternatives selected by the commission, the new line would be between 84 and 105 miles long. The final EIS added that the project also includes construction of a new intermediate Hill Valley substation in Grant County, as well as various modifications at substations in northeast Iowa and southwest Wisconsin, including the Hickory Creek, Turkey River, Stoneman, Nelson Dewey, Eden, Wyoming Valley, and Cardinal substations.
In Wisconsin, the proposed line would begin by crossing the Mississippi River in Cassville, travel northeast to Montfort to connect to the proposed Hill Valley substation, and end at the Cardinal substation in Middleton. The applicants have proposed two different areas where the line would cross the Mississippi River in Cassville, either connecting to the Stoneman substation – existing crossing – or the Nelson Dewey substation – new crossing, the final EIS added.
The proposed electric transmission facilities would cross the counties of LaFayette, Grant, Iowa, and Dane, as well as potentially involve 38 municipalities and townships. The final EIS added that the proposed project would include about 14 miles of 345-kV transmission facilities in Iowa before it reaches Wisconsin. That portion of the applicants’ project starts at the Hickory Creek substation in Clayton County, Iowa, travels north through the Upper Mississippi River National Wildlife and Fish Refuge, and then east across the Mississippi River into Wisconsin.
The final EIS also said that the majority of the line structures for the project would be self-supporting tubular steel monopoles that would range from 120 to 175 feet tall with spans of 750 to 1,100 feet between structures. At the crossing of the Mississippi River, the proposed steel H-frame structures would be between 173 and 198 feet tall with a minimum wire to ground clearance between 91 and 94 feet.
The final EIS added that the project’s overall cost would range between $474m and $560m, depending on the final route alternatives selected. Those costs are estimated in 2023 dollar costs, which is the projected in-service year for the project, the final EIS said, noting that the estimated cost includes substation modifications, the new Hill Valley substation, distribution line relocations, land acquisitions, precertification, and allowance for funds used during construction (AFUDC) for ITC and DPC.
Discussing the need for the project, the final EIS said that the applicants’ stated purposes for the project include to provide economic benefits to Wisconsin customers; avoid the expenditure on reliability and asset renewal projects that would be needed if the project were not built; as well as increase the transfer capability of the electric system between northeastern Iowa and southwest and southcentral Wisconsin, ease congestion, and improve generator competition.
The final EIS noted that commission staff is reviewing the transmission system alternatives provided by the applicants and various other transmission system alternatives that would be more limited in scope and cost as compared to the proposed project. The final EIS noted that the applicants considered several non-transmission and transmission alternatives to the proposed project, as well as numerous transmission alternatives, including construction and upgrades to multiple 138-kV transmission facilities and construction of a new 345-kV transmission line from the Hickory Creek substation in New Vienna, Iowa, to an expanded Nelson Dewey substation in Cassville.
Discussing project route alternatives, the final EIS said that the Mississippi River Routing Area, for instance, is located near Cassville and lies entirely within Grant County. The proposed project provides two separate locations – Nelson Dewey or Stoneman – for crossing the Mississippi River in Cassville. The final EIS added that there are existing 161-kV and 69-kV electric transmission lines that cross the Mississippi River connecting at the Stoneman substation. A new Mississippi River crossing has been proposed that would connect the Wisconsin portion of the proposed project at the Nelson Dewey substation, just north of the Stoneman substation. Each of those crossing options includes two separate route alternatives – North and South – that connect to route alternatives in the Western Routing Area, the final EIS added.
Discussing potential environmental and social impacts, the final EIS noted that the proposed project traverses southwestern Wisconsin from the Mississippi River to Middleton, which is well known and often referred to as the Driftless Area. That area has not been glaciated for at least the last 2.4 million years and consists of significant topographic variation and unique ecological communities found nowhere else in the state.
In addition to the unique terrain and ecology of the Driftless Area, its social and economic significance is often considered unquantifiable to those who live and visit the area, the final EIS said. Concerns for the impacts that the proposed project could and would have on that area are a common theme found throughout the hundreds of comments received on the project, as well as the parties intervening in the proceeding for the project, the final EIS said.
The route alternatives in the Western Routing Area, for instance, range from about 32.54 miles – Western-North – to 50.42 miles – Western-South. The final EIS added that both route alternatives would have about the same amount of new proposed right of way (ROW) – 65% – and follows existing corridors. Western-North primarily follows existing utility infrastructure and roads along its corridor through more open terrain. The final EIS also noted that Western-North would have greater potential to impact more unique ecological resources and communities because it is sited in less disturbed, more remote locations. There are no schools, daycares, or hospitals identified by the applicants within 300 feet of the proposed ROW in that routing area.
The final EIS noted that Western-North has, among other things, the greatest amount of forested lands requiring clearing within the proposed ROW – 95.59 acres – and the greatest amount of wetland areas within the proposed ROW – 16.70 acres.
Of the Eastern Routing Area, the final EIS noted that the routing alternatives in that area range from about 46 miles – Eastern-North – to 48.72 miles – Eastern-South. Eastern-North, for instance, would primarily travel cross-country along new ROW with steep terrain making construction potentially more difficult along that route alternative. Eastern-South primarily follows existing roads and transmission facilities along its corridor through more open and flat terrain. The final EIS said, among other things, that Eastern-North would have greater potential to impact more unique ecological resources and communities because it is sited in less disturbed, more remote locations.