E. COLI in U.S. Drinking Water
Health-based violation data for E. COLI from EPA Safe Drinking Water Information System (SDWIS). Covers all community water systems with violations on record.
E. COLI has been found in violation of EPA standards in 22 water systems across 2 states, with 27 total health-based violations recorded. The most affected states are California, Alabama.
E. COLI is regulated under the EPA Safe Drinking Water Act, which sets enforceable Maximum Contaminant Levels (MCLs) and associated treatment technique requirements for public water systems. The EPA Safe Drinking Water Information System (SDWIS) tracks every recorded violation nationwide and links it back to the specific public water system (PWSID), violation type, and begin date.
Across the United States, PlainEnviro's joined extract contains 27 health-based violation records carrying E. COLI (EPA code 3014) across 22 active community water systems in 2 states. Raw record counts are highest in California, Alabama, with California accounting for 2 records across 2 systems. Health-effect prose is shown only when the official ECHO substance name matches a verified topic; otherwise the portal stays silent rather than inventing guidance.
A health-based violation does not mean residents were necessarily harmed, it means the contaminant exceeded the federal MCL in a compliance sample, triggering notification and remediation requirements. States and utilities maintain primary enforcement responsibility. To check the status of a specific water system, request its most recent Consumer Confidence Report or consult the EPA's Drinking Water Watch portal for the corresponding state.
Violations by State
States ranked by number of health-based violations for E. COLI.
| # | State | Violations | Systems Affected |
|---|---|---|---|
| 1 | California | 2 | 2 |
| 2 | Alabama | 1 | 1 |
Most Affected Water Systems
Top 50 water systems by number of E. COLI health-based violations.
| Water System | State | Violations |
|---|---|---|
| MT. ANDREW WATER AUTHORITY | AL | 1 |
| LAKESIDE MOBILE ESTATES | CA | 1 |
| NORTH TRAILS MUTUAL WATER COMPANY | CA | 1 |
Frequently Asked Questions
Is E. COLI in my water?
E. COLI has been detected in violation of EPA health standards in 22 water systems across 2 states. To check your specific utility, look up your annual Consumer Confidence Report (CCR) - water systems are required to disclose all violations.
How many water systems have E. COLI violations?
EPA SDWIS records show 22 community water systems with health-based E. COLI violations, totaling 27 violations. These represent cases where the contaminant exceeded the EPA Maximum Contaminant Level (MCL).
Which states have the most E. COLI violations?
The states with the most E. COLI violations are: California (2 violations), Alabama (1 violations).
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About This Data
Violation data is from the EPA Safe Drinking Water Information System (SDWIS). Only health-based violations are shown, these include Maximum Contaminant Level (MCL) and Treatment Technique (TT) violations. Monitoring and reporting violations are excluded. Data may not reflect the most current enforcement actions.
Source: U.S. Environmental Protection Agency, SDWIS Federal Reporting Services
Read our methodology - how this data is sourced, computed, and verified.