Data Centers Atlas: Illinois

Weekly data center brief: Illinois

Week of: October 26, 2026

Research through: October 29, 2026

Source reviews and additions to the Atlas collection. Review dates do not establish openings or physical events. Scheduled dates are not outcomes.

Read the complete sourced brief

Dated record: Riverbend Technology Center at Former Alton Steel

Recorded event date: October 26, 2026

Added to the atlas. Compilation date only, not opening or construction.

A recorded date retains its original source and phase scope. A scheduled date does not confirm that the event happened or permission was granted. Source-check dates are separate.

Permit and comment: Karis Critical Hoffman Estates Data Center (Plum Farms)

Village of Hoffman Estates states that the Plum Farms property owner notified it in writing on June 30, 2026 that its rezoning application was withdrawn. The village says existing zoning remains and a future zoning change requires a new application. The canceled July 6 hearing is separate from an accomplished hearing. This is a scoped municipal application record, not a physical shutdown or a measured harm finding.

Record status: unknown. The bounded review establishes the documented action and attributed statements only. It does not establish final resolution of underlying public concerns, present compliance or measured site effects.

Event date: June 30, 2026

Source publication date: Not established

Disposition date: Not established

Concern sources checked: October 22, 2026

June 30, 2026 is the written withdrawal notification date stated by the village. The village notice first publication date is not established. No image timestamp is used as publication evidence.

Raised or recorded by Village of Hoffman Estates.

Village of Hoffman Estates

Counts describe attributed documentation, not harm or severity. Allegations, procedural outcomes and published replies retain their separate scope.

Dated record: Star Innovation District Data Center (Lockport)

Recorded event date: May 28, 2026

Lockport issued its data center discussion suspension news release on May 28, 2026, saying future proposal discussions would pause pending broader regulatory frameworks and June workshops were cancelled. This is the dated City publication, not an exact ordinance adoption day, formal permit denial or physical facility closure.

A recorded date retains its original source and phase scope. A scheduled date does not confirm that the event happened or permission was granted. Source-check dates are separate.

www.cityoflockport.net

Public concern on the record: Star Innovation District Data Center (Lockport)

Residents raised concerns, as recorded by the City of Lockport, that utility, infrastructure and environmental costs of potential Star Innovation District data center development could fall on the community and that local protections might be insufficient without broader oversight. The City release attributes these concerns to residents. It does not establish actual cost shifting, measured harm or resolution of the concerns.

Event date: Not established

Source publication date: May 28, 2026

Disposition date: Not established

Concern sources checked: October 23, 2026

The May 28, 2026 City release describes an earlier workshop but does not establish its exact day in this bounded review. The release date is not substituted for the workshop event day. The original City news release is dated May 28, 2026 for immediate release. Its first website posting day was not independently established.

Raised or recorded by Residents.

City of Lockport

Counts describe attributed documentation, not harm or severity. Allegations, procedural outcomes and published replies retain their separate scope.

Public concern on the record: CyrusOne CHI1-CHI3 (Aurora)

City of Aurora acknowledged noise complaints concerning CyrusOne in an update about scheduled electrical maintenance and daytime generator use. The city described ongoing work toward a solution. This public update does not publish individual complaint files or a count, and it does not establish an adjudicated noise violation.

Record status: unknown. The later disposition of the city-recorded noise concerns is unknown. The company reports mitigation progress, but no independently verified complaint resolution or measured compliance outcome was established in this bounded review.

Event date: April 23, 2026

Source publication date: April 23, 2026

Disposition date: Not established

Concern sources checked: October 18, 2026

The event date records the dated city update, not the unknown first complaint or a complaint filing day. The city page displays April 23, 2026. The later company statement is separately dated October 9.

Raised or recorded by City of Aurora.

Company-published statement

CyrusOne reported that previously scheduled sound-mitigation work at Buildings 2 and 3 was complete and that additional sound-attenuation measures at Building 3 were continuing. This is the company's dated progress statement, not an independent sound measurement or a verified complaint outcome.

The October 9 company update addresses mitigation at the same Aurora campus and provides later context for the recorded noise concerns. It is not presented as an express reply to the city's April 23 article or proof that every complaint is resolved.

Response publication date: October 9, 2026

Response sources checked: October 18, 2026

Counts describe attributed documentation, not harm or severity. Allegations, procedural outcomes and published replies retain their separate scope.

Dated record: Brennan Barrington Hills Data Center

Recorded event date: January 26, 2026

Barrington Hills published its informational meeting cancellation notice on January 26, 2026. The developer declined the presentation, the February 2 meeting was cancelled and the Village considered the matter closed. This is the notice date, not a verified January 28 legal withdrawal, permit denial or physical closure.

A recorded date retains its original source and phase scope. A scheduled date does not confirm that the event happened or permission was granted. Source-check dates are separate.

barringtonhills-il.gov

Public concern on the record: Karis Critical Naperville Data Center

Naperville City Council discussed air dispersion modeling for the proposed Karis Critical data center during its January 20, 2026 meeting. The minutes also record the petitioner representative describing revisions in response to resident concerns and an intended future study. The Council denied the requested conditional use ordinance in a separate motion. These are attributed planning and air review accounts, without independently verified measured harm, a completed study or a finding that concerns were resolved.

Record status: unknown. The final Council minutes document the air review discussion and a separate conditional use denial. That legal decision does not independently establish measured environmental conditions, resolution of the concerns, permanent project abandonment or present computing stage.

Event date: January 20, 2026

Source publication date: Not established

Disposition date: Not established

Concern sources checked: October 23, 2026

The exact January 20, 2026 Council meeting dates this institutional discussion and record. The first day that an individual raised a concern is not established. The final minutes carry a February 4, 2026 print date, which does not independently establish their exact first publication day.

Raised or recorded by Naperville City Council.

City of Naperville Illinois

Counts describe attributed documentation, not harm or severity. Allegations, procedural outcomes and published replies retain their separate scope.

Dated record: Karis Critical Naperville Data Center

Recorded event date: January 20, 2026

The final City Council minutes record the January 20, 2026 denial of the conditional use ordinance and associated variances and owner agreement for the Karis Critical proposal. The motion passed six to one with two abstentions. This is the exact Council legal action date and does not independently establish physical computing closure, a general ban or permanent abandonment.

A recorded date retains its original source and phase scope. A scheduled date does not confirm that the event happened or permission was granted. Source-check dates are separate.

naperville.legistar.com

Dated record: Edged DeKalb Campus (Project Vector)

Recorded event date: December 8, 2025

DeKalb March 18, 2026 project table records City Council approval of Project Vector annexation, annexation agreement, rezoning and concept plan on December 8, 2025. Planning Commission recommendation on December 1 is separate. This is land use approval, not a physical construction start, building permit or opening.

A recorded date retains its original source and phase scope. A scheduled date does not confirm that the event happened or permission was granted. Source-check dates are separate.

www.cityofdekalb.com

Dated record: Lambda Chicago EdgeConneX AI Factory

Recorded event date: August 21, 2025

EdgeConneX announced a Chicago AI facility development for Lambda alongside a separate Atlanta program. August 21, 2025 is the release date. The forecast 2026 service target and existing Chicago air cooled site do not establish that the new AI facility opened.

A recorded date retains its original source and phase scope. A scheduled date does not confirm that the event happened or permission was granted. Source-check dates are separate.

www.edgeconnex.com

Permit and comment: Prime ORD Chicago Campus

Illinois Environmental Protection Agency issued construction permit 24090003 for generator equipment at 1600 East Higgins Road. It is associated here with the existing Prime ORD campus research record through its retained address context. The exact individual building or phase and present operating status are not established by this binding.

Record status: resolved. Illinois Environmental Protection Agency issued this specific construction permit. Resolved describes that dated permit action only; current compliance, subsequent amendments, other permits and physical operating status remain outside this record.

Event date: July 15, 2025

Source publication date: July 15, 2025

Disposition date: July 15, 2025

Concern sources checked: October 18, 2026

The original permit cover gives July 15, 2025 as its issue date. This is the permit action date, not a verified startup day. The official agency index gives July 15, 2025 as the posting date. The separately recorded issue date and the source-check date retain their own meanings.

Raised or recorded by Illinois Environmental Protection Agency.

Counts describe attributed documentation, not harm or severity. Allegations, procedural outcomes and published replies retain their separate scope.

Dated record: Project Cardinal Data Center Campus

Recorded event date: June 10, 2025

Yorkville Project Cardinal page explicitly records the June 10, 2025 annexation agreement public hearing as held, with public comments taken and the hearing closed. This is the hearing outcome only, not annexation approval, a building permit, a site closure or physical construction.

A recorded date retains its original source and phase scope. A scheduled date does not confirm that the event happened or permission was granted. Source-check dates are separate.

www.yorkville.il.us

Permit and comment: Iron Mountain CHI-1

Illinois Environmental Protection Agency issued construction permit 23050030 for emergency-generator equipment at 1680 East Touhy Avenue, associated with Iron Mountain CHI1 in Des Plaines. This is a dated air-permitting action subject to conditions, not verification of first operation, present compliance or every local approval.

Event date: June 5, 2025

Source publication date: June 6, 2025

Disposition date: June 5, 2025

Concern sources checked: October 18, 2026

The original permit cover gives June 5, 2025 as its issue date. This is the permit action date, not a verified startup day. The official agency index gives June 6, 2025 as the posting date. The separately recorded issue date and the source-check date retain their own meanings.

Raised or recorded by Illinois Environmental Protection Agency.

Counts describe attributed documentation, not harm or severity. Allegations, procedural outcomes and published replies retain their separate scope.

Permit and comment: CyrusOne Wood Dale Campus

Illinois Environmental Protection Agency issued construction permit 24060010 for emergency-generator equipment at 460 and 480 Bryn Mawr Avenue, associated with CyrusOne CHI6 in Wood Dale. This is a dated air-permitting action subject to conditions, not verification of first operation, present compliance or every local approval.

Event date: May 16, 2025

Source publication date: May 19, 2025

Disposition date: May 16, 2025

Concern sources checked: October 18, 2026

The original permit cover gives May 16, 2025 as its issue date. This is the permit action date, not a verified startup day. The official agency index gives May 19, 2025 as the posting date. The separately recorded issue date and the source-check date retain their own meanings.

Raised or recorded by Illinois Environmental Protection Agency.

Counts describe attributed documentation, not harm or severity. Allegations, procedural outcomes and published replies retain their separate scope.

Dated record: CyrusOne Wood Dale Campus

Recorded event date: May 13, 2025

CyrusOne published its Wood Dale topping out release on May 13, 2025, reporting that the final structural beam was raised that day. This records the dated construction account and ceremony, not a data center opening, completed campus or proof of current operating service.

A recorded date retains its original source and phase scope. A scheduled date does not confirm that the event happened or permission was granted. Source-check dates are separate.

www.cyrusone.com

Dated record: T5 @ Chicago III (Northlake)

Recorded event date: April 3, 2025

Clune published an account of visits to its active Prime Elk Grove and T5 Northlake construction projects on April 3, 2025. This is the report publication day; the exact tour day, later completion and operation are not established by that account.

A recorded date retains its original source and phase scope. A scheduled date does not confirm that the event happened or permission was granted. Source-check dates are separate.

www.clunegc.com

Dated record: Related Digital South Works Campus (8080 S DuSable Lake Shore Drive)

Recorded event date: March 27, 2025

Related published its northern South Works data center proposal on March 27, 2025 within a wider master plan. This is the release date, not construction, financing close, the southern quantum campus milestone or an opening of this data center.

A recorded date retains its original source and phase scope. A scheduled date does not confirm that the event happened or permission was granted. Source-check dates are separate.

www.related.com

Dated record: T5 @ Chicago V (CHI V)

Recorded event date: March 26, 2025

T5 published its CHI V acquisition and planned development announcement on March 26, 2025. Construction is described prospectively and 2028 occupancy is a target. The publication date is not an exact construction start, utility energization or opening.

A recorded date retains its original source and phase scope. A scheduled date does not confirm that the event happened or permission was granted. Source-check dates are separate.

www.prnewswire.com

Dated record: Compass Datacenters Hoffman Estates Campus

Recorded event date: March 19, 2025

The village Compass update records the first permit for Building 1 and commencement of construction work on March 19, 2025. This is the reported start for that building, not construction or operation of every planned campus building.

A recorded date retains its original source and phase scope. A scheduled date does not confirm that the event happened or permission was granted. Source-check dates are separate.

www.arcgis.com

Permit and comment: T5 @ Chicago III (Northlake)

Illinois Environmental Protection Agency issued construction permit 24020017 for emergency-generator equipment at 11650 West Grand Avenue, associated with T5 at Chicago III. This is a dated air-permitting action subject to conditions, not verification of first operation, present compliance or every local approval.

Event date: February 11, 2025

Source publication date: February 26, 2025

Disposition date: February 11, 2025

Concern sources checked: October 18, 2026

The original permit cover gives February 11, 2025 as its issue date. This is the permit action date, not a verified startup day. The official agency index gives February 26, 2025 as the posting date. The separately recorded issue date and the source-check date retain their own meanings.

Raised or recorded by Illinois Environmental Protection Agency.

Counts describe attributed documentation, not harm or severity. Allegations, procedural outcomes and published replies retain their separate scope.

Dated record: Compass Datacenters Hoffman Estates Campus

Recorded event date: February 17, 2025

The village Compass update records development approval for the campus at the February 17 Village Board meeting. This is the development approval date, not an opening.

A recorded date retains its original source and phase scope. A scheduled date does not confirm that the event happened or permission was granted. Source-check dates are separate.

www.arcgis.com

Permit and comment: Equinix CH5 (Elk Grove Village)

Illinois Environmental Protection Agency issued construction permit 23080013 for emergency-generator equipment at 2001 Lunt Avenue, associated with Equinix CH5. This is a dated air-permitting action subject to conditions, not verification of first operation, present compliance or every local approval. The cover also describes a shared air-permitting source with CH3; the Atlas keeps its two existing research records separate.

Event date: January 15, 2025

Source publication date: January 29, 2025

Disposition date: January 15, 2025

Concern sources checked: October 18, 2026

The original permit cover gives January 15, 2025 as its issue date. This is the permit action date, not a verified startup day. The official agency index gives January 29, 2025 as the posting date. The separately recorded issue date and the source-check date retain their own meanings.

Raised or recorded by Illinois Environmental Protection Agency.

Counts describe attributed documentation, not harm or severity. Allegations, procedural outcomes and published replies retain their separate scope.

Permit and comment: Microsoft Hoffman Estates Data Center

Illinois Environmental Protection Agency issued construction permit 23110003 for emergency-generator equipment at 2045 Lakewood Boulevard, associated with Microsoft Hoffman Estates. This is a dated air-permitting action subject to conditions, not verification of first operation, present compliance or every local approval.

Event date: December 19, 2024

Source publication date: December 20, 2024

Disposition date: December 19, 2024

Concern sources checked: October 18, 2026

The original permit cover gives December 19, 2024 as its issue date. This is the permit action date, not a verified startup day. The official agency index gives December 20, 2024 as the posting date. The separately recorded issue date and the source-check date retain their own meanings.

Raised or recorded by Illinois Environmental Protection Agency.

Counts describe attributed documentation, not harm or severity. Allegations, procedural outcomes and published replies retain their separate scope.

Dated record: KARIS DeKalb Campus (Peace and Gurler Roads)

Recorded event date: July 22, 2024

DeKalb March 18, 2026 project table records City Council approval on July 22, 2024 of the Karis Peace and Gurler Roads amendment to Ordinance 2023 038. The Planning Commission recommendation was July 15. This is the land use amendment action, not a building permit, physical construction start or opening.

A recorded date retains its original source and phase scope. A scheduled date does not confirm that the event happened or permission was granted. Source-check dates are separate.

www.cityofdekalb.com

Dated record: T5 Chicago IV (CHI IV)

Recorded event date: May 2, 2024

T5 published its May 2, 2024 original Grayslake campus announcement. Development and the stated fourth quarter 2027 capacity target were prospective; this dates the issuer publication rather than an accomplished construction or computing start.

A recorded date retains its original source and phase scope. A scheduled date does not confirm that the event happened or permission was granted. Source-check dates are separate.

t5datacenters.com

Dated record: T5 @ Chicago III (Northlake)

Recorded event date: October 3, 2023

T5 published its Chicago III Northlake acquisition announcement on October 3, 2023. An acquisition and future development plan are not an exact construction start or opening.

A recorded date retains its original source and phase scope. A scheduled date does not confirm that the event happened or permission was granted. Source-check dates are separate.

t5datacenters.com

Dated record: CoreSite CH2

Recorded event date: November 10, 2022

CoreSite published a CH2 media advisory describing a June 2020 opening and a planned community celebration. This is the publication date, not an exact physical opening or a completed future celebration.

A recorded date retains its original source and phase scope. A scheduled date does not confirm that the event happened or permission was granted. Source-check dates are separate.

www.coresite.com

Dated record: T5 Chicago II

Recorded event date: November 8, 2022

T5 published its Chicago II second phase and availability release on November 8, 2022. The account describes leasing and future delivery. This is the publication date, not a first opening or proof that the full forecast phase became available.

A recorded date retains its original source and phase scope. A scheduled date does not confirm that the event happened or permission was granted. Source-check dates are separate.

t5datacenters.com

Dated record: Sangha Systems Hennepin (82 River North)

Recorded event date: November 12, 2020

DPO published its November 12, 2020 original issuer report of mining at the Sangha Hennepin facility. This dates publication of a historical operating account, without an exact first operating day or independent verification of present computing service.

A recorded date retains its original source and phase scope. A scheduled date does not confirm that the event happened or permission was granted. Source-check dates are separate.

www.prnewswire.com