Sierra Club v. Wisconsin Department of Natural Resources

Sierra Club requested review by the Wisconsin Circuit Court of a decision by the Wisconsin Department of Natural Resources (DNR) to issue a Final Air Pollution Control Construction Permit and Operation Permit to a data center project without completing an environmental impact statement (EIS) under the Wisconsin Environmental Policy Act (WEPA). Sierra Club alleged that the first phase of the planned data center campus is expected to consist of four buildings occupying 672 acres of previously agricultural and open land and will require filling in 4.7 acres of wetlands. It will need 1.3 gigawatts of electrical power to operate, more than all households in Milwaukee County combined, requiring new high-voltage transmission lines and gas-fired power plants. The campus will also include 45 industrial-sized diesel generators. Around-the-clock construction on the campus began in December 2025. WEPA requires that DNR “must prepare a draft EIS, provide an opportunity for public review and comment, hold a public hearing, and prepare a final EIS responding to comments received” for any “major action significantly affecting the quality of the human environment.” Wisconsin Administrative Code chapter NR 150 details additional procedural requirements for drafting an EIS, including providing an opportunity for public review and comment and holding a public hearing. DNR did not provide an EIS for the data center project. Instead it provided an Environmental Analysis Summary and Environmental Analysis Supplement. Sierra Club alleged that DNR failed to meet its obligations under WEPA and NR 150 by not drafting an EIS and by not providing an opportunity for public comment or holding a public hearing. Sierra Club claimed that the assessment was insufficient in part because the agency failed to obtain comment from the Public Service Commission, which has jurisdiction and expertise with regard to the transmission and generation projects associated with the data center. It further alleged that DNR failed to consider climate change impacts associated with the buildout of gas-fired power plants to meet the project’s energy demands and whether those facilities are consistent with the State’s clean energy and greenhouse gas reduction goals, among other impacts. Sierra Club requested that the court reverse or remand the agency’s decision that an EIS was not required and set aside or remand the approval of the project’s Air Pollution Control Construction Permit until the agency complies with WEPA.