Drinking-water safety · Systems with violations
States With the Most Drinking-Water Violations
Community water systems with at least one health-based Safe Drinking Water Act violation since 2016, by state.
Texas leads "States With the Most Drinking-Water Violations" at 1,723 systems.
| # | State / item | Systems with violations |
|---|---|---|
| 1 | Texas 4,617 systems total | 1,723 systems |
| 2 | California 3,071 systems total | 1,014 systems |
| 3 | Pennsylvania 1,782 systems total | 724 systems |
| 4 | Oklahoma 884 systems total | 653 systems |
| 5 | Louisiana 819 systems total | 517 systems |
| 6 | North Carolina 1,963 systems total | 471 systems |
| 7 | Missouri 1,679 systems total | 440 systems |
| 8 | Illinois 1,785 systems total | 420 systems |
| 9 | Arizona 954 systems total | 414 systems |
| 10 | New Mexico 592 systems total | 407 systems |
| 11 | Colorado 1,113 systems total | 394 systems |
| 12 | Wisconsin 977 systems total | 370 systems |
| 13 | New York 2,202 systems total | 356 systems |
| 14 | Florida 1,516 systems total | 354 systems |
| 15 | Oregon 941 systems total | 323 systems |
Method: Raw counts favor larger states; see the violation-rate ranking to compare fairly.
Source: EPA Safe Drinking Water Information System (SDWIS) · 2026 Q1 refresh; violations since 2016