Grayslake data-center campus faces legal challenge after village approval

Residents have filed a lawsuit seeking to block Grayslake’s approved T5 Data Center Campus, putting a legal challenge over one of the largest proposed developments in the village.

Village materials describe a campus that could include up to 18 buildings totaling more than 10 million square feet across approximately 472 acres. The village has estimated the private investment at $18 billion. Early site work and regrading had begun by late 2025.

Infrastructure work is also planned

Lake County records show related infrastructure activity in the development area, although the county documents do not attribute those projects solely to the data center. An Arbor Vista water-main extension in Grayslake, along U.S. 45 near Illinois 120, is scheduled to complete design in 2026. County transportation records also list intersection improvements at Washington and Atkinson, with a Sept. 18, 2026, letting date for construction and engineering entries.

Local reporting and public postings indicate that Lake County residents filed the lawsuit in early August 2026. The formal allegations, parties and requested relief have not been publicly detailed in the cited posting. The village’s T5 information page says it cannot provide further responses because of impending litigation and advice of counsel. The Sept. 18 transportation-project letting is the next identified public date connected to nearby infrastructure work.