U.S. Environmental Protection Agency (EPA) — National drinking water standards and compliance data. All U.S. municipal water systems are required to report annually. epa.gov
Environmental Working Group (EWG) Tap Water Database — Independent analysis of water quality data from nearly 50,000 U.S. water utilities. Cross-references EPA data with health-based guidelines that are often stricter than legal limits. ewg.org/tapwater
Health Canada — Guidelines for Canadian Drinking Water Quality — Federal guidelines that set maximum acceptable concentrations for contaminants in Canadian drinking water. Provinces enforce their own standards based on these guidelines. canada.ca
Municipal Annual Water Quality Reports — Every city publishes an annual Consumer Confidence Report (U.S.) or Water Quality Report (Canada) detailing what was found in their water supply. The data shown here reflects recent published reports from each municipality.
ORP & Molecular Hydrogen Values — ORP (Oxidation-Reduction Potential) and dissolved H₂ measurements are based on published research and independent third-party testing of municipal water supplies and Kangen water systems. ERW values reflect readings from Enagic SD501 and K8 machines at standard settings.