# Tap Water Lookup

> Independent guide to United States public drinking-water records. The site reports measurements and regulatory references without assigning a safety rating.

## Data sources
- EPA UCMR 5 occurrence data: final release, August 2026; samples 2023-01-03 to 2026-06-17
- EPA SDWIS/ECHO: 2026Q2
- EPA public-water-system service-area boundaries: EPA ORD SAB Model v3.0 (CWS layer), file Wed, 02 Sep 2026 21:43:10 GMT
- U.S. Census Bureau: TIGER/Line 2024 ZCTA5 (2020 ZCTAs); 2020 relationship files

## Publication
- Database built: 2026-09-03T16:31:55
- Current rollout wave: 1 of 3
- ZIP pages require material system-specific data; unavailable ZIP URLs permanently redirect to an aggregate county or state page.
- Comparisons retain source units, use annual sampling-point averages where EPA requires them, and distinguish regulatory limits from non-regulatory health references.

## Site structure
- https://www.tapwaterlookup.com/water-quality/ — states, counties, and launched ZIP reports
- https://www.tapwaterlookup.com/water-system/ — launched public-water-system records
- https://www.tapwaterlookup.com/contaminant/ — contaminant definitions and nationwide statistics
- https://www.tapwaterlookup.com/guides/ — interpretation, testing, and treatment guides
- https://www.tapwaterlookup.com/news/ — manually reviewed U.S. official announcements, with publication dates and proposal status
- https://www.tapwaterlookup.com/statistics/ — full imported UCMR 5 system counts, denominators, and dated state statistics
- https://www.tapwaterlookup.com/alerts/ — official advisory resources and account briefing preferences; not a live emergency feed
- https://www.tapwaterlookup.com/community/ — user-contributed discussions; not verified EPA measurements
- https://www.tapwaterlookup.com/methodology/ — joins, thresholds, limitations, and validation
- https://www.tapwaterlookup.com/sitemap-index.xml — canonical URL inventory