Methodology

Where Zini looks

This site never invents a contaminant level, letter grade, or citation. If a public API does not cover a city, Zini says so and cites whatever official country-level source exists. A street address is geocoded onto the map; the water file is still the utility or commune, and the UI says so.

United States

Live queries against EPA Enforcement and Compliance History Online (ECHO) Safe Drinking Water Act web services, which draw from the federal Safe Drinking Water Information System (SDWIS). We use get_systems, get_qid, and get_dfr, then link the detailed facility report and SDWIS Federal Reports. Consumer Confidence Reports are linked via EPA's CCR page — this app does not scrape utility PDFs. For a resolved US public water system we also join cached official snapshots: SDWIS service-line inventory counts (not address-level pipe material) and UCMR 5 PFAS occurrence (detects at or above the UCMR minimum reporting level, or an explicit “not in this snapshot”).

Private wells, some transient systems, and bottled brands are outside SDWIS. A missing utility is reported as missing, not as a pass. Lead-service-line counts are for the whole system; this site will not invent the material of the pipe on your street. UCMR 5 is occurrence monitoring — a result at or above the UCMR MRL is not automatically an SDWA violation. Snapshot refresh: src/data/README.md.

France

Commune lookup via geo.api.gouv.fr, then official sanitary-control results from Hub'Eau qualité eau potable (SISE-Eaux). The official conclusion text is shown as published.

Everywhere else

Population using safely managed drinking-water services (%) from the WHO Global Health Observatory, accessed through the WHO GHO API (WSH_WATER_SAFELY_MANAGED). Snapshot retrieved 2026-01-23. washdata.org. This is a national modelled estimate, not a kitchen-tap sample.

National regulators are listed so you can go to the agency that actually oversees the tap. The EU Drinking Water Directive is cited for member states.

Places and the map

Geocoding uses OpenStreetMap Nominatim (and, for some US lookups, the US Census Bureau geocoder). Map tiles are OpenStreetMap. Clicking the map reverse geocodes, then runs the same water lookup as search.

Back to the map