Environmental Impact Analysis_Content Page_Port Washington Data Center

Port Washington Data Center Proposal

Vantage Data Centers (Vantage) has proposed the construction of a data center campus in the city of Port Washington in Ozaukee County. The proposed Lighthouse campus would be constructed on 672 acres. Vantage owns a total of 1,644 acres. The Lighthouse campus would be located on the southern portion of this property, approximately 1 mile inland from Lake Michigan, in a mostly agricultural area. The proposed project requires DNR permits and approvals related to wetlands, stormwater, and air emissions. Additionally, the city of Port Washington is seeking sanitary sewer extensions and amendments. 

The DNR has conducted an environmental analysis of Vantage's proposed project. The DNR is also cooperating with the Public Service Commission (PSC) in its review of the American Transmission Company's proposed Ozaukee County Distribution Interconnection Project, which involves the transmission of electricity to Vantage's proposed data center campus. More information on that review is available on the PSC's E-Services Portal.

REQUIRED PERMITS AND APPROVALS

WETLAND PERMIT EXEMPTIONS

On December 11, 2025, DNR granted three nonfederal wetland exemption determinations. 

STORM WATER PERMIT APPLICATIONS

Vantage submitted four applications for coverage under the stormwater construction site general permit: one on Aug. 22, 2025, followed by three on Oct. 2, 2025. The DNR has administratively consolidated these applications.

On Dec. 11, 2025, the DNR conveyed stormwater permit coverage for project areas 1 & 2 (including laydown area 4) and construction laydown areas 1, 2, and 3.

AIR PERMIT APPLICATIONS

On Aug. 29, 2025, Vantage submitted applications for a minor source construction permit and an initial operation permit for the proposed data center. The air pollution emission sources identified in the applications include 45 diesel-fired emergency generators capable of a combined power output of 87 megawatts. Once the DNR has completed its environmental analysis, it will continue processing these air permit applications and will subsequently publish a public notice of the DNR’s preliminary determination on their approvability, followed by a 30-day public comment period.

MUNICIPAL SERVICES

On Sept. 22, 2025, the Southeastern Wisconsin Regional Planning Commission (SEWRPC) submitted a request for administrative approval of an amendment to SEWRPC's regional water quality management plan to extend the Port Washington Sewer Service Area to include the proposed data center campus.

The City of Port Washington has submitted the following:

  • On Sept. 25, 2025, plans & specifications for the construction of a water supply main to service the proposed data center campus.
  • On Sept. 25, 2025, plans & specifications for the construction of a sanitary sewer interceptor to service the proposed data center campus.
  • On Oct. 10, 2025, a request for coverage under the stormwater construction general permit.

ENVIRONMENTAL ANALYSIS

The DNR has conducted an environmental analysis as part of its review of the permit applications and plans it has received on Vantage's proposed data center project. Under the Wisconsin Environmental Policy Act (WEPA), state agencies are required to analyze, consider and publicly disclose the environmental and socioeconomic impacts of certain agency actions. 

On Dec. 9, 2025, the DNR released an Environmental Analysis Summary on Vantage's proposed Project.

On Dec. 11, 2025, the DNR issued a WEPA Compliance Determination.

PUBLIC DISCLOSURE

This webpage will be updated when new materials are available to ensure consistent and thorough disclosure of the DNR's environmental analysis, permitting and plan reviews. The DNR's review of Vantage's air permit applications will include a public comment period, which will be publicly noticed.

Please use the DNR hearings and meetings calendar to stay aware of upcoming public notices and hearings.