Clear answers from public data
TapCheck CA helps California residents understand what public water-system monitoring shows for their ZIP — in plain English, without scare tactics.
Who we are
TapCheck CA is a consumer information product. We match a California ZIP to a public water system (preferring official service-area boundaries when available), then summarize curated detections from State Water Board SDWIS extracts next to legal limits and California health guidelines.
What we use
Public data. Monitoring results and system metadata from California drinking-water datasets (SDWIS / EDT Library extracts), plus service-area boundary data where we have it. See methodology for matching confidence and coverage limits.
What we are not
- Not a laboratory. We do not sample your faucet or certify home plumbing.
- Not your water utility. We are not affiliated with local utilities, cities, or the State Water Board. Confirm the system name on your bill.
- Not EWG or any advocacy scorecard. We are not affiliated with the Environmental Working Group or similar rating sites.
- Not medical advice. Talk with a clinician about health questions.
- Not a plumber marketplace price list. Optional installer contact is a soft request form only — we do not show plumber plan prices on this site.
Optional local help
If you want a licensed filtration installer to explain options, you can leave contact info. Independent partners covering your ZIP may follow up. No obligation.