All water systems in Ohio
4,165 systems
About this data
Rules violated counts the rules a system was in violation of in the past three years, including monitoring and reporting lapses; one rule can carry several violations. Unresolved is the number of those rules currently in violation at EPA's latest data refresh.
Source: the U.S. EPA's Enforcement and Compliance History Online system (ECHO), which publishes the federal Safe Drinking Water Information System. EPA's terms and values are shown as published. The Ohio records are from EPA's data refresh of Oct 7, 2026; EPA refreshes this data quarterly, and states report to EPA with a lag of three to six months, so the newest violations may not appear yet.