Data-center law in Illinois

55 ILCS 5/5-12001 (Counties Code, as amended by P.A. 104-468, eff. June 16, 2026)

Effective 2026-06-16 · Applies to both

Gives a county board the power to regulate and restrict the location, use, and intensity of buildings and land for trade, industry, and other uses outside the limits of cities, villages, and incorporated towns that have their own zoning ordinances, including establishing zoning districts and setback lines.

A data center sited in unincorporated county territory obtains its zoning approval, rezoning, or special use permit under this authority; a data center sited within a municipality proceeds instead under that municipality's own home-rule or non-home-rule zoning ordinance, which supersedes the county's plan inside the corporate limits.

Source: Full text of law

220 ILCS 5/4-101 (Public Utilities Act)

Applies to both

Gives the Illinois Commerce Commission general supervision of every public utility, including examining rates, charges, and service adequacy and enforcing compliance with the Public Utilities Act. A data center's electric service agreement, and any new interconnection or large-load tariff question the serving utility raises, is administered under the Commission's jurisdiction established here. The section's own source note (from Ch. 111 2/3, par.

4-101, showing it predates Illinois's mid-1980s statutory recompilation) cites only a 2021 amendment, P.A. 102-538, that added a critical-infrastructure security policy requirement; the source note does not date the general-supervision grant itself, so no single day-precise commencement date is stated here for that clause.

Source: Full text of law

415 ILCS 5/12 (Environmental Protection Act)

Applies to both

Bars constructing, installing, or operating equipment capable of causing or contributing to water pollution without an Illinois EPA permit, and separately bars discharging a contaminant into State waters, including through a point source, without an NPDES permit. A data center's cooling-water discharge or an increase in the quantity of a discharge permits under this section. The Illinois Compiled Statutes' own source note lists amendments running through P.A. 104-417 (eff. Aug.

15, 2025), each touching a specific subsection such as the private sewage disposal system provision; the source note does not state which enactment first added the general permit requirements in subsections (b) and (f) that this instrument cites, so no single day-precise commencement date is stated here for those clauses.

Source: Full text of law

415 ILCS 5/9 (Environmental Protection Act)

Applies to both

Bars constructing, installing, or operating equipment capable of causing or contributing to air pollution, of a type the Pollution Control Board designates by regulation, without a permit granted by the Illinois Environmental Protection Agency. A data center's backup diesel generator fleet, one of the largest air-permitting questions a large data center raises, permits under this section and the Agency's new and modified source rules.

The Illinois Compiled Statutes' own source note for this section cites only P.A. 103-794 (eff. Jan. 1, 2025), which added a grain-elevator exemption; the source note does not date the general permit requirement in subsection (b) that this instrument cites, so no single day-precise commencement date is stated here for that clause.

Source: Full text of law

20 ILCS 605/605-1025 (P.A. 101-31, 2019, as amended by P.A. 104-468, eff. June 16, 2026)

Effective 2026-06-16 · Applies to private

The Department of Commerce and Economic Opportunity issues certificates of exemption from the Retailers' Occupation Tax Act, the Use Tax Act, the Service Use and Service Occupation Tax Acts, and local retailers' occupation taxes, plus an income tax credit, to a qualifying Illinois data center.

A qualifying data center is one that makes at least $250 million in collective capital investment over a 60-month period and creates at least 20 full-time equivalent jobs paying at least 120 percent of the county average wage, and that certifies carbon neutrality or green-building certification within two years of being placed in service.

The certificate's duration may not exceed 20 calendar years, contractors and subcontractors must meet responsible-bidder and project-labor-agreement requirements, and the Department may not issue a new certificate after July 1, 2029.

Source: Full text of law