{"@context":"https://schema.org","@type":"Dataset","@id":"https://zipradar.org/topic/water-quality/59601/","name":"Water quality for ZIP 59601 — Helena, MT","description":"Water quality data for ZIP 59601 (Helena, Montana), sourced from EPA SDWIS.","topic":{"slug":"water-quality","label":"Water quality","source":"EPA SDWIS","sourceUrl":"https://www.epa.gov/ground-water-and-drinking-water/safe-drinking-water-information-system-sdwis-federal-reporting","refreshCadence":"Quarterly (federal mandate)","summary":"Pages show the largest community water system on record for the ZIP's county, its PWSID and population served, and its health-based and total violations in the last 3 years. Lead and copper sampling results are not shown; your utility's annual water quality report (CCR) has them.","limitations":"Where a county has several water systems, zipradar shows the one serving the most people and says how many others are on record; yours may be a different one. Private well water is not covered."},"place":{"zip":"59601","city":"Helena","state":"MT","stateFull":"Montana","county":"Lewis and Clark County","countySlug":"lewis-and-clark-county","geo":{"latitude":46.5891,"longitude":-112.0391}},"stateContext":{"topConcern":"Radon Zone 1, wildfire","narrative":"Montana is uniformly Zone 1 radon. Wildfire risk concentrates in the western mountains; the 2017 + 2021 + 2024 seasons all set records. EPA SDWIS shows compliance disparity between Helena/Missoula/Billings and small rural systems."},"radonZone":null,"airQuality":null,"waterQuality":{"primary":{"pwsid":"MT0000241","name":"HELENA WATER SYSTEM","populationServed":32091,"waterSource":"SW","violations":{"windowYears":3,"total":0,"healthBased":0,"latest":null}},"systemCount":56,"caveat":"This is federal SDWIS reporting data for the community water system serving this county, not an address-level test result. Private well water is never covered by SDWIS. Where a county is served by multiple systems, this shows the one serving the most people."},"datePublished":"2026-04-24","dateModified":"2026-09-24","canonicalUrl":"https://zipradar.org/topic/water-quality/59601/","zipDashboardUrl":"https://zipradar.org/zip/59601/","zipDashboardApiUrl":"https://zipradar.org/api/zip/59601/","primarySourceUrl":"https://www.epa.gov/ground-water-and-drinking-water/safe-drinking-water-information-system-sdwis-federal-reporting","license":{"content":"CC-BY-4.0","attribution":"zipradar.org — https://zipradar.org/topic/water-quality/59601/"}}