Contaminant 1011 in U.S. Drinking Water
Health-based violation data for Contaminant 1011 from EPA Safe Drinking Water Information System (SDWIS). Covers all community water systems with violations on record.
Contaminant 1011 has been found in violation of EPA standards in 12 water systems across 6 states, with 35 total health-based violations recorded. The most affected states are Massachusetts, Texas, Colorado.
Contaminant 1011 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, SDWIS records show 35 health-based violations for Contaminant 1011 affecting 12 community water systems in 6 states. Violation counts cluster heaviest in Massachusetts, Texas, Colorado, with Massachusetts alone accounting for 12 violations across 2 systems. The contaminant is listed on the federal primary drinking water regulations.
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 Contaminant 1011.
| # | State | Violations | Systems Affected |
|---|---|---|---|
| 1 | Massachusetts | 12 | 2 |
| 2 | Texas | 8 | 3 |
| 3 | Colorado | 4 | 1 |
| 4 | California | 2 | 1 |
| 5 | North Dakota | 2 | 1 |
| 6 | Kansas | 1 | 1 |
Most Affected Water Systems
Top 50 water systems by number of Contaminant 1011 health-based violations.
| Water System | State | Violations |
|---|---|---|
| BILLERICA WATER WORKS | MA | 7 |
| CONCORD WATER DEPT | MA | 5 |
| RIVERSIDE WC | CO | 4 |
| CITY OF CUSHING | TX | 4 |
| CRWA LAKE DUNLAP WTP | TX | 3 |
| SUMMIT MUTUAL WATER COMPANY | CA | 2 |
| FARGO CITY OF | ND | 2 |
| EMPORIA, CITY OF | KS | 1 |
| RAYBURN COUNTRY MUD | TX | 1 |
Frequently Asked Questions
Is Contaminant 1011 in my water?
Contaminant 1011 has been detected in violation of EPA health standards in 12 water systems across 6 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 Contaminant 1011 violations?
EPA SDWIS records show 12 community water systems with health-based Contaminant 1011 violations, totaling 35 violations. These represent cases where the contaminant exceeded the EPA Maximum Contaminant Level (MCL).
Which states have the most Contaminant 1011 violations?
The states with the most Contaminant 1011 violations are: Massachusetts (12 violations), Texas (8 violations), Colorado (4 violations), California (2 violations), North Dakota (2 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 U.S. Environmental Protection Agency, SDWIS Federal Reporting Services
Read our methodology - how this data is sourced, computed, and verified.