A group of Lake County residents has filed a lawsuit to block a 472-acre data center campus in Grayslake, which they call a project of “unprecedented scale” that was given approval without adequate public disclosure.
The Preservation of Community Well-being Collective LLC and nine residents of Lake County filed the suit on July 31 in Lake County Circuit Court.
The legal action challenges the Village of Grayslake’s approvals of the T5 @ Chicago IV data center campus.
The lawsuit complaint names the Village of Grayslake, T5 Data Centers, LLC, and Alter Asset Management Company as defendants.
It asks the court to declare the 2024 to 2025 approvals invalid, to void the development agreement between the village and T5 Data Centers and to permanently enjoin the village from issuing further permits in reliance on the approvals.
The T5 @ Chicago IV campus, as approved by the Grayslake Village Board between September 2024 and May 2025, calls for up to 472 acres of development, more than 10 million square feet of buildings and an electrical demand of approximately 1.55 gigawatts of power supplied by ComEd, with associated diesel backup generation infrastructure.
The data center will be located in Cornerstone, a $750 million, 641-acre mixed-use development near Peterson Road and Alleghany Road. Alter Asset Management Company is the master developer of Cornerstone and an affiliate of The Alter Group, which is the owner of the development.
The complaint alleges that the project is fundamentally inconsistent with the village’s own Comprehensive Plan, Sustainability Plan and its Zoning Ordinance.
It also alleges that the village’s approvals were the course of conduct that failed to provide the transparency and reasoned deliberation required by state law.
Five of the nine individual plaintiffs are residents of the Village of Round Lake Park where they reside in the Saddlebrook Farms community, which is an age-restricted residential neighborhood annexed in 1996.
Their homes have Grayslake mailing addresses but sit directly across Alleghany Road from the T5 site.
Another plaintiff is a long-time resident of the Arbor Vista subdivision in Grayslake and has cultivated a one-acre wildlife habitat for more than 30 years.
Another plaintiff is the heir to a residential property on North Alleghany Road, less than 500 yards from the T5 site, with a three-season room and deck facing the campus directly.
Another lives in central Grayslake, approximately three miles north-northeast of the property.
Attorneys for the plaintiff say a utility pole for transformers was installed adjacent to their home in connection with the T5 campus, “illustrating that the physical impacts of the T5 campus and its supporting infrastructure extend well beyond the immediate vicinity of the Subject Property and into established residential neighborhoods of the Village.”
The lawsuit alleges four legal violations, the first of which alleges the village’s approvals departed from its own comprehensive planning framework in a manner inconsistent with Illinois substantive due process.
The second alleges that meaningful public participation was undermined because official public notices and agendas referred to the project only by the applicant’s code-name, “T5@Chicago IV,” and did not disclose the “hyperscale data center character” of the development until the very last agenda in the approval sequence.
The complaint points to a September 9, 2024, public hearing where the last residential uses in the Cornerstone development were eliminated, clearing the way for the data center project.
According to village minutes cited in the lawsuit, the hearing was opened at 6:02 p.m. and closed at 6:03 p.m. with no public comment — two weeks before the first T5 hearings began.
The third alleged legal violation accuses the village of violating the Illinois Open Meetings Act.
The suit said that Grayslake Mayor Elizabeth Davies and the board trustees have personal email accounts and personal devices on which they routinely conduct village business, including regarding the T5 approvals.
The fourth alleged legal violation accuses the village of authorizing the data center despite not having such a category in its own zoning ordinance.
The lawsuit additionally said that six village officials, in podcast interviews and public statements before and after the approvals, have described a development pattern that had been “set in line” and “20 years advanced.”
Attorneys also say the developer’s engineering consultant inaccurately described the project as having “broad community acceptance” in a wetland assessment report submitted to the United States Army Corps of Engineers in May.
The plaintiffs’ attorney, Chloe A. Russell, of the Plainfield-based Law Office of Ronald D. Cummings, said the case is not about opposing technology or economic development.
“It is about whether a village of just over 20,000 people, using zoning tools designed for ordinary commercial development, can approve a project of unprecedented scale in a way that materially affects thousands of neighbors, including neighbors who live in other municipalities and had no procedural role in the decision,” Russell said.
“The plaintiffs are homeowners, heirs to family property, and long-term neighbors. Their homes, their water, their air, and their communities are being materially affected by a decision they had no meaningful voice in. They are asking the court to enforce the law,” she added.
T5 CEO Pete Marin announced last week, just before the lawsuit was filed, that his company had suspended its wetlands permit application for the project.
“We’ve partnered with local communities to build safe, sustainable, and responsibly operated data centers in Illinois and all across the country for over 20 years. We appreciate the importance of wetland areas and the bond that local communities share with them and the wildlife ecosystems they support,” Marin said.
“We’ve successfully managed wetland remediation projects in many regions and always consider local readiness and support before moving forward with those plans. Given the extent of community questions and concerns about wetland remediation in Grayslake, we’ve volunteered to indefinitely suspend our permit application for wetland remediation,” he added.
Marin additionally said his company is fully committed to continuing its partnership with local officials and delivering a development that is “not only sustainable, but also produces over 1,600 jobs, uses less water than virtually any other industrial or commercial project, and has virtually no effect on electric rates for residents or local businesses.”
“The Cornerstone Development at Grayslake is slated to generate over half a billion dollars in new revenue for local school districts and hundreds of millions more for local emergency and social services. We look forward to more actively communicating these benefits to the community and building a lasting partnership with every resident, much as we have in other communities across Illinois,” Marin said.
Marin told Lake and McHenry County Scanner Saturday morning that his company “will of course respond to any legal claims in that forum.”
“But we’re confident we’ve followed the letter and intent of every law and regulation every step of the way. Our goal is to bring a great facility to the region that will not just power the smartphones, computers, and technology that we all rely on everyday, but will also deliver well over $1,500,000,000 in new taxes and fees to the benefit of Grayslake Village and Lake County,” Marin added.
“This is a once-in-a-lifetime investment, and Grayslake residents and their leaders will get to determine how to use it.”
The Village of Grayslake told Lake and McHenry County Scanner that they have not been served with the suit yet and are unable to comment on it since they have not reviewed it in detail.
The Lake County Board is set to hold a public hearing at 1 p.m. on August 18 at Lake County Central Permit Facility in Libertyville regarding whether the county should establish a temporary moratorium on data centers in unincorporated areas.
An initial status hearing in the lawsuit has been set for 9 a.m. on October 30 in Lake County Courtroom 301.