What Idaho 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.
IdahoPublishes for some schools
Published action level, as verified in 2026: 15 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.
Idaho publishes results, but we have not yet ingested them row by row, so this page carries no counts or rates for it — only what the survey verified about the publication itself. We publish a figure once we hold the rows it is computed from, and not before. The jurisdiction’s own results are linked below.
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.
Changed since the 2021 baseline: action level.
Our field note for Idaho, 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.
⚠️ CORRECTED 2026-09-17 on direct read of the IDEQ page. We had carried NASBE's 20 ppb unverified (evidence was 'secondary' and the note read 'Confirms NASBE'). IDEQ's own page does NOT say 20 anywhere -- ZERO occurrences of '20 ppb' or '20 parts per billion' -- and states 15 ppb three times, verbatim: 'fountains should be taken out of service if the lead exceeds 15 parts per billion (ppb)', 'If the initial sample results from a tap or fountain exceed 15 ppb, interim measures can be taken', and 'If initial and follow-up sample results from a tap or fountain exceed 15 ppb, you should examine permanent options for lead reduction.' The page also uses no phrase 'action level' at all. Either Idaho moved off 20 since NASBE's April-Aug 2021 survey or NASBE recorded it wrongly; we publish what the state's own current page says. PUBLISHING IS ALSO NOW PRIMARY-CONFIRMED, not second-hand: the page carries an inline results table of 671 rows across 87 distinct facilities (public schools, high schools, Head Starts, licensed daycares, and one juvenile detention centre), collection dates 2021-07-07 to 2026-03-26, reported in mg/L with a '# of students' column. That makes the programme CURRENT, not of unestablished vintage, and the tier T2 (structured table, extraction needed) rather than T3 (PDF/FOIA only). Highest reported result 0.250 mg/L = 250 ppb. Testing is voluntary via the Idaho Bureau of Laboratories, so coverage stays partial. ⚠️ CONSEQUENCE: Idaho is NO LONGER at the top of the action-level range. Tennessee at 20 ppb is now the sole most-permissive jurisdiction; the 1-to-20 ppb / 20x spread still holds via Rhode Island and Tennessee, both primary-confirmed.
TapWaterData Editorial. "School drinking water lead testing: Idaho." TapWaterData national school drinking-water lead testing database. Last updated 2026-09-17. Licensed under CC BY 4.0. https://www.tapwaterdata.com/school-lead-testing/idaho
@misc{tapwaterdata_school_lead_2026,
author = {TapWaterData Editorial},
title = {School drinking water lead testing: Idaho},
year = {2026},
howpublished = {\url{https://www.tapwaterdata.com/school-lead-testing/idaho}},
note = {Last updated 2026-09-17. 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 .
All 51 jurisdictions — the national scorecard, the tier map, and the methodology behind every rating on this page.
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