Data: U.S. EPA Safe Drinking Water Information System (SDWIS) via the EPA Envirofacts API, retrieved October 30, 2026. SDWIS data is reported by the state (NH DES) and may lag by a quarter or more. This site is independent and not affiliated with the EPA, NH DES or any water system. Nothing here is a test of your own tap. Methodology · Editorial standards · Report a correction · About