“I think that as long as this environmental review is actually going through, right now because of the lawsuit, I think there should be a pause,” Crowley said.

The review follows a settlement involving the Wisconsin Department of Natural Resources, the Sierra Club and Vantage Data Centers. The agreement resolves a Sierra Club lawsuit challenging the DNR’s decision to issue permits for Vantage’s data center campus in Port Washington without first preparing a full environmental impact statement. The DNR must complete its statewide analysis by January 2028, and Vantage will pay its full cost.

The study is expected to examine data centers’ direct and cumulative effects on water use, greenhouse gas emissions, wildlife and energy consumption. The DNR also must create a public website with study documents, notices and opportunities for public participation.

Republican gubernatorial candidate Tom Tiffany, Crowley’s opponent, said his administration would require the DNR to ensure projects meet strict environmental standards before issuing permits. The department said public input will be a critical part of the analysis and that the findings will help inform future state and local policy decisions.

The dispute over the Port Washington project has raised questions about how Wisconsin evaluates large data center developments. The Sierra Club filed suit in July, arguing the DNR should have required a full environmental impact statement. Midwest Environmental Advocates, a nonprofit law firm that assisted with the case, says the state’s environmental policy law requires such reviews for major actions with significant environmental effects.

Michael Greif, a legal fellow at Midwest Environmental Advocates, said data center development is driving a large buildout of gas-fired power plants in Wisconsin. The group cited a Public Service Commission report that identified the Port Washington project and two others as contributing to a projected 40% increase in statewide energy demand over the next six years. Greif said the resulting power plants could bring air pollution to nearby communities.

Vantage said it supports a fact-based discussion about responsible data center development and agreed to fund the independent review. The company said the DNR will control how the analysis is developed.

The settlement’s requirement for an independent statewide assessment could give residents and policymakers information about the costs and impacts of data center growth before additional decisions are made. The DNR said it will provide further details once plans for the study are finalized.