T5 Data Centers Lawsuits: The Grayslake Case Seeking to Void a 472 Acre, 1.55 Gigawatt Campus

T5 is not a hyperscaler and does not own the workloads that would run at Grayslake. On its own account it is a developer, a data center general contractor, and an operations provider, founded in 2008, with divisions covering development and ownership, construction, and facilities management. Its own site claims 22 data centers developed, roughly 4 million square feet, general contractor licensure in 48 states, and more than 3 gigawatts of capacity managed. That profile explains the shape of the litigation: a developer's exposure is concentrated at the approval stage, before a building exists to make noise or draw water, which is precisely where this case sits.

It also explains the co-defendants. The suit names the Village of Grayslake, which granted the approvals, and Alter Asset Management, which assembled the 641 acre Cornerstone development, alongside T5. When residents want approvals voided, they have to sue the body that issued them and the parties who hold them. Being named in a case like this is not an allegation of harm to any neighbor's health or property; it is a consequence of holding the entitlement under challenge. Our full report on the Grayslake case covers the complaint and the response.

The plaintiffs plead four things: that the approvals departed from the village's comprehensive planning framework so sharply as to violate substantive due process; that public participation was inadequate because notices identified the project only as T5@Chicago IV and the hearing that removed the remaining residential uses lasted 61 seconds; that officials violated the Illinois Open Meetings Act by doing public business on personal email and devices; and that the village approved a data center under a zoning code containing no data center category. None of it has been adjudicated.

T5's answer is that the process was clean. Marin has said publicly that the company followed the letter and intent of every law and regulation every step of the way, that it will respond to legal claims in that forum, and that the project would generate well over $1.5 billion in new taxes and fees for Grayslake and Lake County, including more than half a billion dollars for local schools, plus more than 1,600 jobs. He also said the company volunteered to suspend its wetland remediation permit application indefinitely, which pauses a federal approval while the state case runs.

The case matters beyond Illinois because the remedy is the strong one. Voiding approvals is what killed the Prince William Digital Gateway in Virginia over a public notice defect, and the same counsel filed the Joliet Technology Center case two months earlier, making Grayslake the second front in a coordinated Illinois challenge to fast-tracked approvals. If a large project near you is moving, our guide to fighting a proposed data center and our zoning appeal deadlines guide are the place to start, and our free case review connects you with an independent attorney in our network who handles data center cases in your state, at no cost and with no obligation.