{"@context":"https://schema.org","@type":"Dataset","@id":"https://zipradar.org/topic/water-quality/94941/","name":"Water quality for ZIP 94941 — Mill Valley, CA","description":"Water quality data for ZIP 94941 (Mill Valley, California), 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":"94941","city":"Mill Valley","state":"CA","stateFull":"California","county":"Marin County","countySlug":"marin-county","geo":{"latitude":37.9059,"longitude":-122.545}},"stateContext":{"topConcern":"Wildfire (WUI), seismic, water-supply variability","narrative":"California carries the highest concentrated WUI wildfire risk in the US per USFS WHP, with FAIR Plan + non-renewal pressure intensifying since 2017 fires. FEMA NFHL coverage is strong; drinking-water systems vary from large urban (LADWP, EBMUD) to small disadvantaged community systems flagged in EPA SDWIS. Radon risk is mostly Zone 2-3."},"radonZone":null,"airQuality":null,"waterQuality":{"primary":null,"systemCount":0,"note":"zipradar has no EPA water-system record for this ZIP yet. That is a gap in our records, not a sign that the water is untested. Your water utility's annual water quality report (Consumer Confidence Report) has the results; if the home is on a private well, the owner or the county health department is the place to ask.","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/94941/","zipDashboardUrl":"https://zipradar.org/zip/94941/","zipDashboardApiUrl":"https://zipradar.org/api/zip/94941/","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/94941/"}}