How it works
How WaterHealthCheck Works
Four steps from ZIP code to personalised water quality report. All data is from public federal records. Reports are free and always will be.
Enter your ZIP code — we find your utility
Your ZIP maps to the public water system serving your address, drawn directly from EPA's Safe Drinking Water Information System. SDWIS covers every public utility in the U.S. — 47,038 of them. We find yours automatically.
Source: EPA SDWIS (quarterly update)Tell us about your household
Select who drinks your water: pregnant, trying to conceive, infant, immunocompromised, longevity-focused, or just yourself. This calibrates which contaminants we surface first and what risk thresholds matter most for your biology. A pregnant person has different lead and nitrate sensitivities than a healthy adult. We account for that.
Informed by NTP, IARC, and CDC exposure guidanceYour personalised report
We compare every contaminant detected in your utility's water against two benchmarks: EPA Maximum Contaminant Levels (the legal limit) and EWG health guidelines (stricter, health-protective limits derived from peer-reviewed toxicology). Each contaminant gets a status — ok, warn, or alert — and an explanation of what it means for your specific household profile.
Includes UCMR5 PFAS results where availableFilter recommendations based on your water
Filter recommendations are generated from your actual contaminant profile — not from generic advice. A utility with high trihalomethanes gets different guidance than one with PFAS or nitrate issues. The recommendation reflects what's actually in your water and which filter technologies address it.
No affiliate relationships — recommendations are data-drivenA note on the data
Everything in your report comes from public federal databases — the same sources regulators, researchers, and journalists use. We don't estimate, interpolate, or extrapolate. If a measurement doesn't exist in the record, we say so.
Reports reflect utility-level data. Your point-of-use conditions — older pipes, building plumbing — may vary. That's explained in the report where relevant.
Read the full methodology →Common questions
Is this actually free?
Yes. Reports are free and always will be. No email required to run a report.
Where does the data come from?
All data comes from public federal records: EPA SDWIS for utility monitoring results, UCMR5 for PFAS data, and EWG health guidelines as a secondary benchmark. We don't collect private water data or run our own tests.
How current is the data?
EPA SDWIS data syncs weekly. UCMR5 is ingested when EPA publishes updates. State supplementary data is updated annually where available.
Does this cover well water?
No. WaterHealthCheck covers public water utilities only. Private wells are not monitored by EPA and are not in SDWIS.
What if my utility isn't in the results?
If we can't find your utility or data isn't available yet, we'll tell you that directly rather than showing empty or estimated results. We're adding utilities as the data pipeline matures.
Free · No account required · 30 seconds
Ready to check your water?
Enter your ZIP and see what's in your utility's water — personalised for your household, source-linked, always free.
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