Tap-water monitoring depends on the utility serving the location. The Metropolitan Waterworks Authority covers Bangkok, Nonthaburi and Samut Prakan; the Provincial Waterworks Authority provides monitoring context for many areas outside that network. Use Department of Health standards to interpret parameters, not as a substitute for a current reading.
MWA stations report parameters such as residual chlorine, turbidity, conductivity, pH, chloride and salinity. Match the station and timestamp to the relevant service area instead of treating one station as all of Bangkok.
PWA's public monitoring supports areas outside the MWA network, but dashboard coverage and available parameters vary. Confirm the responsible utility and nearest relevant station before using a value.
Utility monitoring describes the network at monitored points. Building tanks, internal pipes and local interruptions can affect water at a particular tap. For a health-critical question, use current utility notices or an appropriate sample test.