T5 Data Centers Suspends Grayslake Wetland Permit Amid Suit

T5 Data Centers has voluntarily suspended the wetland-fill permit application for its Grayslake, Illinois campus, the Atlanta-based developer confirmed, as a lawsuit seeking to void the project’s local approvals moves forward in Lake County. CEO Pete Marin said the company pulled the application “given community questions and concerns about wetland remediation in Grayslake,” even as site work on the roughly 472-acre campus continues elsewhere.

Why it matters

Grayslake is a live data point in a pattern developers are underwriting nationally: power availability alone no longer clears a site. T5 secured 1.55 gigawatts of ComEd capacity and cleared the village’s zoning and site-plan process between September 2024 and May 2025, yet a still-pending suit and public pressure were enough to make the company retreat on one permit voluntarily rather than fight it out. For site-selection teams, that is the signal. Litigation risk and process-integrity challenges are now a co-gating factor alongside interconnection queues, and friction like this is exactly what pushes hyperscale demand toward jurisdictions with less organized local opposition.

The numbers

The suspended application covered 15.75 acres of wetland fill on the broader site, which spans up to 472 acres and could hold as many as 20 buildings and more than 10 million square feet. T5 @ Chicago IV is designed for up to 1.2 gigawatts of leasable IT capacity, backed by 1.6 gigawatts of secured utility power, with the first phase, three 60-megawatt buildings, targeted for Q4 2027. The opposition coalition’s lawsuit, filed through the Law Office of Ronald D. Cummings, asks a court to vacate the village’s approvals as inconsistent with Grayslake’s own adopted policies and reached through a deficient process, including inadequate hearings and no third-party review.

What’s next

Construction continues on already-permitted portions of the national campus while the wetland application sits suspended and the underlying suit proceeds; T5 has not said when, or whether, it will refile. The same Plainfield firm representing Grayslake’s opposition also represents challengers to data-center approvals in Yorkville and Joliet, Illinois, a sign this is becoming a repeatable legal playbook rather than a one-site dispute. How Lake County’s court rules on the deficient-process claim will matter well beyond Illinois for developers weighing entitlement risk against power access.