Lake County, IL

T5 @ Chicago IV Data Center Campus

T5 Data Centers. Approved. 1550 MW.

T5 Data Centers and landowner Alter Asset Management won a series of Grayslake village approvals between September 2024 and May 2025 for an 18 building, 472 acre, up to 1.55 gigawatt data center campus near Peterson and Alleghany roads in the Cornerstone development, backed up by diesel generation. On July 31, 2026 the Preservation of Community Well-Being Collective and nine residents sued Grayslake, T5 and Alter, alleging the village violated the Open Meetings Act and hid the project's hyperscale nature from public notices; an initial status hearing is set for October 30, 2026.

Status: Approved
Operator: T5 Data Centers
Applicant on record: T5 Data Centers
Location: Grayslake, Lake County, IL
Size: 1550 MW, 472 acres, 10,000,000 sq ft
Cooling: Not reported
Utility: ComEd
Next hearing: October 30, 2026, Lake County Circuit Court
First reported: 2024-09
Last updated: August 29, 2026

Sources

'Project of unprecedented scale': Lake County residents file lawsuit to block 472-acre data center campus in Grayslake, Lake & McHenry County Scanner, 2026-08-08
Despite village approvals, legal action expected against Grayslake data center, Daily Herald, 2026-06-08

What it would mean nearby

The cooling design has not been reported. If it uses evaporative cooling, a 1550 MW facility would draw roughly 4.9 million to 17.7 million gallons of water a day, about what 56,500 households use.

This case does not change what a household pays today, but it is the main tool Illinois regulators are using to try to stop the cost of new grid equipment for data centers from landing on residential bills. ComEd annual reconciliation rate case (docket 25-0383) adds about $3.10 a month to a typical bill from January 2026. PJM capacity auction price spike hits ComEd supply charges adds about $10.50 a month to a typical bill from June 2025.

For a noise estimate and the three distance rings, check your own address.