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Illinois CCR Requirements

Illinois community water systems operate under a distinctive workflow: the Illinois Environmental Protection Agency (IEPA) generates a computer-populated data report each year through its Drinking Water Watch portal, giving systems a populated starting point rather than a blank form. That report is not a finished CCR — systems must add required content, review for errors, and deliver to customers by July 1.

Who issues a CCR in Illinois

The Illinois Environmental Protection Agency (IEPA), Bureau of Water, Division of Public Water Supplies serves as the primacy agency for public drinking water in Illinois. IEPA's drinking water program oversees compliance with both federal Safe Drinking Water Act requirements and Illinois-specific primary drinking water standards.

Illinois has approximately 1,868 active community water systems (CWS), collectively serving roughly 12.1 million people. The CWS universe ranges from large municipal systems in Chicago and the surrounding region down to small mobile home parks and homeowner associations in rural counties. Any CWS serving at least 25 year-round residents or operating 15 or more service connections must prepare and distribute an annual CCR.

The CCR requirement applies to community water systems only. Non-community systems — transient non-community (restaurants, campgrounds) and non-transient non-community (schools, workplaces) — are not required to issue CCRs under federal or Illinois rules.

Illinois's CCR rule on top of the federal floor

The federal CCR rule lives at 40 CFR Part 141, Subpart O (§§ 141.151–141.156). Illinois codifies its corresponding requirements at 35 Illinois Administrative Code (Ill. Adm. Code) Part 611, Subpart U — Consumer Confidence Reports. [VERIFY: Confirm that Subpart U is the correct lettered subpart and that no separate subpart letter was introduced by recent LCRI-related amendments; ilga.gov access was blocked during research.]

Illinois adopted the federal CCR rule as its state rule, which means the federal requirements — including the 2024 revisions and the 2027 effective dates — flow through Illinois primacy. Systems in Illinois must follow the federal compliance schedule under § 141.152 in addition to any IEPA-specific procedural requirements (such as the certification filing described below).

Cornell LII hosts the current federal text at 40 CFR Part 141 Subpart O.

The IEPA computer-generated CCR report

Illinois runs one of the more developed state-level CCR assistance programs. Each year, IEPA populates a system-specific data report through its Drinking Water Watch portal at water.epa.state.il.us. The report pulls monitoring results, violation history, and water quality data the system has already submitted to IEPA through routine compliance reporting. IEPA makes it available online; systems download it as a starting point.

The 2025 reporting cycle report (covering calendar year 2024 data) was made available in early 2025.

What the computer-generated report includes:

What the computer-generated report does not include — and what the system must add:

The IEPA-generated report does not, by itself, satisfy the full Consumer Confidence Rule. Systems treat it as a populated data table, not a finished document.

After completing the CCR, systems must certify delivery to IEPA. As of 2024, IEPA discontinued its customized CCR Certification Form; systems use the combined certification form available through IEPA's drinking water compliance forms page. Certification must be filed within 10 days of delivery under the 2024 federal rule revisions (40 CFR § 141.155), down from the prior 3-month window.

For systems unfamiliar with the full content requirements, IEPA references EPA's CCR iWriter tool and its own Sample Collectors Handbook as supplementary guidance.

Lead service line context: Illinois leads the country

Illinois has more lead service lines than any other state. IEPA's own 2020 reporting data counted 667,275 reported lead service lines out of approximately 3.85 million total service lines statewide — and that count excludes 819,000-plus connections listed as "unknown material," meaning the true number is likely higher. EPA's 2023 national estimate put Illinois's count at over one million lines. No other state approaches that scale.

This matters for CCR compliance now, and it matters more beginning November 1, 2027, when the Lead and Copper Rule Improvements (LCRI) take effect. For the full disclosure and sampling implications, see LCRI 2027: What Illinois Systems Need to Know.

Under LCRI, every Illinois CWS must:

The LCRI also lowers the lead action level from 15 µg/L to 10 µg/L (0.010 mg/L) beginning November 1, 2027. Given the volume of lead service lines in the state, a larger share of Illinois systems will face action-level exceedances under the new threshold than under the current one. Systems with existing lead service line replacement plans should confirm those plans are updated to meet LCRI's 10-year replacement schedule.

Illinois enacted the Lead Service Line Replacement and Notification Act (effective January 1, 2022), which imposes state-level inventory and replacement obligations that run alongside the federal LCRI. Contact IEPA's Division of Public Water Supplies Compliance Assurance Section at EPA.LeadandCopper@illinois.gov with questions specific to the state program.

Deadlines and delivery

Primary deadline: July 1. Illinois follows the federal default. Every CWS must deliver the CCR covering the prior calendar year by July 1. A report covering calendar year 2025 data is due by July 1, 2026.

Parent supplier data deadline: April 19. Under Illinois's implementation, parent water suppliers must deliver data to their satellite systems by April 19 of each year, giving retail systems time to incorporate that data before the July 1 deadline.

Biannual delivery (≥ 10,000 served). Systems serving 10,000 or more persons must distribute the report twice per calendar year beginning January 1, 2027. The second report is due by December 31. This requirement comes from 40 CFR § 141.155(j)(2), enacted by the 2018 America's Water Infrastructure Act and fully effective starting with reports covering 2026 data.

Certification: 10 days post-delivery. Under the 2024 federal rule revisions, systems must certify CCR delivery to IEPA within 10 days of completing distribution — a significant tightening from the prior 3-month window.

Online posting (≥ 50,000 served). Systems serving 50,000 or more persons must post the current year's report on a publicly accessible website, per 40 CFR § 141.155(f).

Smaller systems (≤ 500 served). Systems serving 500 or fewer persons may meet reduced delivery requirements — posting notice in at least one location frequented by customers and notifying them annually that the report is available on request — rather than mailing a paper copy to each customer, per 40 CFR § 141.155(g)(2).

What's changing in 2027 for Illinois systems

Three distinct federal requirements become fully effective beginning January 1, 2027 (for 2026 data, delivered by July 1, 2027), with LCRI adding a fourth on November 1, 2027. Illinois systems face all four. For a full breakdown of the rule changes, see What's New in the 2027 CCR Rule.

Mandatory summary section. Every CCR must now include a summary at the beginning of the report per 40 CFR § 141.156, which was added by the 2024 revisions (effective January 1, 2027). The summary must present key findings in plain language and may include infographics.

Biannual delivery. Systems serving 10,000 or more must begin distributing the CCR twice per year, with the second delivery due by December 31. This is new in 2027.

PFAS reporting. By April 26, 2027, every CWS must complete initial monitoring for the six PFAS regulated under EPA's April 2024 National Primary Drinking Water Regulation (89 FR 32532): PFOA (MCL: 4.0 ng/L), PFOS (MCL: 4.0 ng/L), PFHxS (MCL: 10 ng/L), PFNA (MCL: 10 ng/L), HFPO-DA/GenX (MCL: 10 ng/L), and a Hazard Index of 1 for any mixture of two or more of {PFHxS, PFNA, HFPO-DA, PFBS}. Results from that monitoring must appear in the 2027 CCR. MCL compliance (enforceable) begins April 26, 2029.

On the state side: Illinois has been conducting PFAS sampling at all CWS through its Statewide Investigation Network. In April 2025, IEPA notified 47 systems of right-to-know obligations triggered by Part 620 groundwater standard amendments that adopted PFAS standards aligned with the federal MCLs. The Illinois Pollution Control Board adopted those Part 620 amendments in October 2025. [VERIFY: Confirm whether the Illinois Part 611 (drinking water MCLs) has separately adopted state PFAS MCLs mirroring the federal NPDWR, or whether only Part 620 groundwater standards have been updated. The IEPA April 2025 press release addresses right-to-know under a different mechanism than the federal CCR rule's PFAS reporting obligation.]

LCRI — November 1, 2027. This is where Illinois faces its most acute compliance challenge. The new lead action level (10 µg/L), the paired first-and-fifth-liter sampling protocol at lead service line sites, and the 10-percent-per-year replacement mandate all take effect simultaneously. Given Illinois's lead service line inventory — the largest in the country — no other state has more systems that will be affected. Systems that have not yet inventoried, planned for, or communicated about lead service line replacement will need to move fast to meet both the state notification requirements and the new CCR disclosure language. See LCRI 2027 for the full operational picture.

For an overview of all CCR requirements, return to the CCR Resources hub or explore state-by-state requirements.

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Last reviewed: 2026-05-03. Next scheduled review: November 2026 (annual cadence per IA Decision 9).