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Drinking Water Violations by County
Which counties' water systems have open health-based drinking water violations.
Northeastern Connecticut Planning Region, Connecticut has the most, 34 drinking-water health violations, followed by Polk County, Florida (32) and Monterey County, California (32).
Open the live map →🚰Counties with the most drinking-water health violations
🔎About this data
How many community water systems in the county have a current health-based violation in EPA's records: a contaminant over its legal limit, or a required treatment step not done. Missed paperwork isn't counted. A system serving several counties is counted in its main county. Your utility's yearly water-quality report has the details.
Source: U.S. EPA SDWIS via ECHO drinking-water download (September 30, 2026)
Coverage: Nationwide (counties)
How it was checked: Texas county totals add up to 4,749 active community water systems vs 4,747 in the Texas Commission on Environmental Quality's 2025 compliance report (0.04% apart).
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💬Questions and answers
Which county has the most drinking-water health violations?
Northeastern Connecticut Planning Region, Connecticut has the most, 34 drinking-water health violations, followed by Polk County, Florida (32) and Monterey County, California (32).
Where does this data come from?
U.S. EPA SDWIS via ECHO drinking-water download (September 30, 2026). Coverage: Nationwide (counties).
Is the map free to use?
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Numbers computed from the live map data on October 18, 2026. Free to quote with credit to “Map the Block (maptheblock.com)”; see reuse terms.