Lead in Illinois school drinking water

What Illinois publishes about lead testing in its schools’ drinking water, what those numbers cover, and how we checked it. One row of a 51-jurisdiction survey, verified jurisdiction by jurisdiction rather than compiled from a single list.

IllinoisPublishes nothing (confirmed at source)

Publishing status: Publishes no results
Coverage: No published results, so there is no coverage to rate
Data vintage: currency not established by the evidence we hold
Evidence: confirmed at sourceConfirmed at source 2026-08-09

Action level

Published action level, as verified in 2026: 5 ppb

Action levels are not comparable between jurisdictions: across the 51 we surveyed they run from 1 ppb to 20 ppb, so a share of results above “the action level” measures the threshold as much as it measures the water. We never rank states on it. Where a jurisdiction explains how its own level was set, the verified research note at the foot of this page records the explanation verbatim.

No published results

We found no school lead testing results published by Illinois. That is confirmed at source: we checked the jurisdiction's own pages or data platform and found no results in them.

An absence of published results is a fact about disclosure, not about water. It says nothing about whether schools here have been tested, and nothing about what a test would find.

What changed since 2021

The baseline is the National Association of State Boards of Education’s 2021 survey. Every 2026 value below was re-checked for this survey; a value that did not move is a finding too.

Testing required: 2021 baseline: Yes · verified 2026: Yes
Action level: 2021 baseline: 5 · verified 2026: 5
Publishes results: 2021 baseline: No · verified 2026: No

Nothing in this row moved between the 2021 baseline and our 2026 verification.

Source and verification

What we checked: https://dph.illinois.gov/topics-services/environmental-health-protection/lead-in-water/testing-schools-child-care-facilities.html
Checked on: 2026-08-09 — confirmed at source
Machine readability: T4 — a programme exists but no public results surface was found

Verified research note

Our field note for Illinois, published verbatim rather than summarised. Where it quotes a figure from a source, that is the source’s own number reproduced as we recorded it, not a rate we computed — everything we compute states its denominator and its unit.

REQUIRES TESTING BUT PUBLISHES NO RESULTS - verified directly at IDPH: the page describes requirements only, with no database, spreadsheet, map or download. Pre-2000 buildings serving pre-K-grade 5 had to test and report to IDPH by end of 2018; schools notify parents directly above 5 ppb, so no cross-school comparison is possible. IDPH review found most schools detected lead in at least one source.

Cite this page

TapWaterData Editorial. "School drinking water lead testing: Illinois." TapWaterData national school drinking-water lead testing database. Last updated 2026-08-09. Licensed under CC BY 4.0. https://www.tapwaterdata.com/school-lead-testing/illinois

@misc{tapwaterdata_school_lead_2026,
  author       = {TapWaterData Editorial},
  title        = {School drinking water lead testing: Illinois},
  year         = {2026},
  howpublished = {\url{https://www.tapwaterdata.com/school-lead-testing/illinois}},
  note         = {Last updated 2026-08-09. Licensed under CC BY 4.0}
}

Published under a Creative Commons Attribution 4.0 (CC BY 4.0) licence — free to republish, chart or build on with attribution. Last updated 2026-08-09.

All 51 jurisdictions — the national scorecard, the tier map, and the methodology behind every rating on this page.