PROJECT STATUS: Received final Public Service Commission of Wisconsin approval in May 2026.
Project Overview
- Colburn Substation – Planned by Adams-Columbia Electric Cooperative as a separate project, this new substation in Adams County will serve area load growth and electric reliability.
- New ATC Facilities – ATC is building and installing facilities to interconnect the new, planned ACEC Colburn Substation to the regional electric grid to improve the networking and reliability of existing electric infrastructure in the region.
Project Description
ATC is making system upgrades to connect the new, planned ACEC Colburn Substation to the regional electric grid. The Colburn Substation is planned for a site near the intersection of Bighorn Avenue and 7th Avenue in the town of Big Flats. The project will also provide an additional source to the existing 69-kilovolt, Y-302 circuit which will bring greater reliability to three existing local distribution substations.
This ATC project includes:
- Building approximately 4.5 miles of new, 69-kV power line from the ACEC Cottonville Substation to the new ACEC Colburn Substation. This new power line will be an extension to the existing ATC 69-kV, Y-302 power line in the town of Big Flats. The extended line will run on the south side of Bighorn Avenue from 7th Avenue to 11th Avenue.
- Building approximately 5.1 miles of new, 69-kV power line from the ACEC Badger West Substation to State Highway 13. This new power line will be built in the towns of Rome and Monroe. It will also be an extension to the existing ATC 69-kV, Y-302 power line.
- Improving networking service to three ACEC substations.
- Expanding the ACEC Badger West Substation to create a new 138-kV to 69-kV connection point on the system.
Project Need
The project supports the connection of the proposed ACEC Colburn Substation to the regional electric grid to ensure electric reliability and address current and future energy needs in the surrounding area. It will provide a second source for the new and existing loads served by the power line, and help relieve constraints on the current electric delivery system, improve reliability and support local energy demand.
The ATC project was approved by the Public Service Commission of Wisconsin in May 2026.
Additional information about the ATC project can be found on the PSCW website, under docket number 137-CE-213.
