About TapWaterGuide
A free, worldwide reference for tap water safety — built for travelers deciding whether to drink the tap, and for anyone checking the quality of their own city's water.
What We Cover
TapWaterGuide currently covers 205 countries and territories and 268 cities (100 US, 168 international), each with a safety rating, water source detail, known contaminant concerns, and practical guidance. We rate every destination on a simple four-tier scale: Safe, Generally Safe, Caution, and Not Safe.
Data Sources & Methodology
World Health Organization (WHO)
WHO Guidelines for Drinking-water Quality inform our understanding of international safety benchmarks and inform country-level ratings, particularly for travel health context.
US EPA (Environmental Protection Agency)
The Safe Drinking Water Act and its National Primary Drinking Water Regulations set the legal compliance standard referenced on every US city page, including limits for lead, arsenic, disinfection byproducts, and PFAS.
Environmental Working Group (EWG)
EWG's Tap Water Database and related research inform the contaminant context on US city pages, particularly around contaminants regulated below EPA's legal limits but above EWG's more precautionary health guidelines.
US CDC (Centers for Disease Control and Prevention)
CDC Travelers' Health guidance informs our country-level traveler precautions and food-and-water safety recommendations for international destinations.
National & municipal water utilities
Individual water authority public reports (consumer confidence reports, annual water quality reports) inform source, treatment, and hardness detail for specific cities.
How We Rate
Tap water is safe to drink nationwide or citywide with no special precautions.
Safe in most areas, with documented regional or historical exceptions worth knowing about.
Municipally treated but not generally recommended for direct drinking; bottled or boiled water advised.
Not safe to drink from the tap; bottled, boiled, or properly filtered water is necessary.
Accuracy & Corrections
Hardness, pH, and TDS figures on city pages are typical ranges, not live measurements. Water chemistry varies by neighborhood, season, and source blend, so the figure for your own tap can differ. Your utility's annual water quality report is the authoritative record.
We do not publish contaminant concentrations unless they are taken directly from a utility's report and linked to it. A September 2026 review found that contaminant tables previously shown on city pages did not meet that standard, and they were removed.
US compliance notes are checked against the EPA's Safe Drinking Water Information System. That database lags real events and an empty record is not proof of a clean one, so treat compliance notes as a starting point.
If you find an error, email info@tapwaterguide.org with the page and a source. Corrections are made in the next site update.
Disclaimer
TapWaterGuide is an informational reference, not medical or travel advice. Water quality and infrastructure conditions change over time, including through drought, natural disasters, and infrastructure failures. Always check current local advisories, your accommodation, or your embassy's travel health guidance before making decisions about drinking water, especially for infants, pregnant travelers, or those who are immunocompromised.