Total Coliform (RTCR) in U.S. Drinking Water
Health-based violation data for Total Coliform (RTCR) from EPA Safe Drinking Water Information System (SDWIS). Covers all community water systems with violations on record.
Total Coliform (RTCR) has been found in violation of EPA standards in 6,908 water systems across 53 states, with 16,278 total health-based violations recorded. The most affected states are Oklahoma, Arkansas, California.
Total Coliform (RTCR) 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 16,278 health-based violations for Total Coliform (RTCR) affecting 6,908 community water systems in 53 states. Violation counts cluster heaviest in Oklahoma, Arkansas, California, with Oklahoma alone accounting for 1,131 violations across 430 systems. EPA health-effect summaries describe the specific exposure concerns that drove the federal standard.
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.
What are the health effects of this contaminant?
Total coliform bacteria are indicators of potential fecal contamination in water. Their presence suggests the water may contain disease-causing pathogens.
Source: U.S. Environmental Protection Agency. Consult your doctor for personalized health guidance U.S. Environmental Protection Agency. Consult your doctor for personalized health guidance
Violations by State
States ranked by number of health-based violations for Total Coliform (RTCR).
| # | State | Violations | Systems Affected |
|---|---|---|---|
| 1 | Oklahoma | 1,131 | 430 |
| 2 | Arkansas | 915 | 186 |
| 3 | California | 887 | 236 |
| 4 | Vermont | 678 | 216 |
| 5 | Nebraska | 312 | 138 |
| 6 | Missouri | 308 | 84 |
| 7 | Puerto Rico | 241 | 57 |
| 8 | Louisiana | 187 | 50 |
| 9 | Texas | 164 | 92 |
| 10 | Florida | 158 | 56 |
| 11 | Utah | 91 | 46 |
| 12 | Alaska | 61 | 22 |
| 13 | Washington | 60 | 18 |
| 14 | Idaho | 52 | 32 |
| 15 | Oregon | 48 | 30 |
| 16 | Connecticut | 44 | 15 |
| 17 | Arizona | 41 | 17 |
| 18 | New York | 32 | 16 |
| 19 | Mississippi | 31 | 12 |
| 20 | New Mexico | 28 | 11 |
| 21 | Massachusetts | 21 | 14 |
| 22 | Indiana | 17 | 13 |
| 23 | Pennsylvania | 16 | 13 |
| 24 | American Samoa | 16 | 3 |
| 25 | Georgia | 15 | 7 |
| 26 | Michigan | 15 | 9 |
| 27 | Minnesota | 15 | 5 |
| 28 | Kansas | 13 | 9 |
| 29 | Montana | 13 | 11 |
| 30 | Tennessee | 11 | 6 |
| 31 | Virginia | 11 | 8 |
| 32 | Hawaii | 10 | 1 |
| 33 | Kentucky | 10 | 9 |
| 34 | New Jersey | 10 | 6 |
| 35 | Colorado | 9 | 7 |
| 36 | District of Columbia | 9 | 2 |
| 37 | South Carolina | 9 | 7 |
| 38 | Wisconsin | 9 | 7 |
| 39 | West Virginia | 8 | 3 |
| 40 | Nevada | 7 | 3 |
| 41 | North Dakota | 7 | 5 |
| 42 | Illinois | 6 | 4 |
| 43 | North Carolina | 6 | 5 |
| 44 | South Dakota | 5 | 4 |
| 45 | Maine | 4 | 3 |
| 46 | Rhode Island | 4 | 2 |
| 47 | Wyoming | 4 | 3 |
| 48 | Northern Mariana Islands | 4 | 2 |
| 49 | Alabama | 3 | 1 |
| 50 | Maryland | 3 | 2 |
| 51 | New Hampshire | 3 | 2 |
| 52 | Delaware | 2 | 1 |
| 53 | Ohio | 1 | 1 |
Most Affected Water Systems
Top 50 water systems by number of Total Coliform (RTCR) health-based violations.
Frequently Asked Questions
Is Total Coliform (RTCR) in my water?
Total Coliform (RTCR) has been detected in violation of EPA health standards in 6,908 water systems across 53 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 Total Coliform (RTCR) violations?
EPA SDWIS records show 6,908 community water systems with health-based Total Coliform (RTCR) violations, totaling 16,278 violations. These represent cases where the contaminant exceeded the EPA Maximum Contaminant Level (MCL).
Which states have the most Total Coliform (RTCR) violations?
The states with the most Total Coliform (RTCR) violations are: Oklahoma (1,131 violations), Arkansas (915 violations), California (887 violations), Vermont (678 violations), Nebraska (312 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.