TapGraded

States Ranked by Health-Based Violations per Capita

US states and territories ranked by health-based drinking-water violations per 100,000 people served over the most recent five-year window.

How this is measured

Total health-based Safe Drinking Water Act violations (a distinct-violation count over the most recent five-year window) reported by active community water systems (CWS) in each state, divided by the total population those systems serve, expressed per 100,000 people served. States are ranked from most violations per capita (worst) downward.

Population served is summed across a state’s community water systems and can exceed residential population where systems overlap or resell water, so this is a per-capita rate over population served, not over census population.

# State Health-based violations (5y) People served Per 100,000
1 Alaska 985 701,132 140.49
2 Oklahoma 4,892 3,581,603 136.59
3 New Mexico 1,575 1,988,192 79.22
4 West Virginia 635 950,899 66.78
5 Louisiana 2,991 5,165,961 57.9
6 Montana 357 816,767 43.71
7 Idaho 560 1,584,441 35.34
8 New Hampshire 304 884,031 34.39
9 Wyoming 178 539,928 32.97
10 Kansas 755 2,856,903 26.43
11 Maine 163 687,468 23.71
12 Arkansas 676 3,037,761 22.25
13 Vermont 99 461,054 21.47
14 Arizona 1,045 4,900,820 21.32
15 Colorado 1,497 7,217,482 20.74
16 Texas 6,266 33,087,345 18.94
17 Missouri 1,108 5,882,217 18.84
18 Puerto Rico 332 1,825,029 18.19
19 Nebraska 299 1,714,088 17.44
20 Oregon 622 3,755,319 16.56
21 Mississippi 402 3,116,385 12.9
22 Wisconsin 380 3,046,565 12.47
23 South Dakota 112 930,000 12.04
24 Pennsylvania 1,062 11,450,408 9.27
25 Connecticut 249 2,820,514 8.83
26 Nevada 263 3,134,139 8.39
27 California 2,934 40,366,501 7.27
28 North Carolina 695 9,664,876 7.19
29 Indiana 370 5,217,170 7.09
30 Washington 673 9,607,826 7
31 Minnesota 319 4,730,761 6.74
32 Utah 214 3,728,252 5.74
33 Georgia 599 10,618,265 5.64
34 North Dakota 41 743,533 5.51
35 Kentucky 268 5,098,882 5.26
36 Illinois 613 11,807,141 5.19
37 Michigan 374 7,479,677 5
38 Delaware 24 526,737 4.56
39 Iowa 132 3,019,942 4.37
40 Virginia 285 6,966,109 4.09
41 District of Columbia 27 670,882 4.02
42 Rhode Island 40 1,056,286 3.79
43 New Jersey 332 8,840,246 3.76
44 Ohio 379 10,088,268 3.76
45 Maryland 164 5,368,671 3.05
46 South Carolina 135 4,811,314 2.81
47 Florida 594 22,075,019 2.69
48 Tennessee 167 7,031,370 2.38
49 New York 426 18,236,402 2.34
50 Alabama 137 6,324,050 2.17
51 Massachusetts 144 9,972,144 1.44
52 Hawaii 3 1,502,981 0.2

See how the Tap Grade is calculated on the methodology page, or where the underlying data comes from on data sources. Spotted something that looks wrong? Email contact@tapgraded.com.

Source: EPA SDWIS/ECHO + UCMR5 (see Methodology) · Data as of 2026Q2 — EPA SDWA/ECHO quarterly bulk data (2026 Q2) downloaded 2026-07-16; EPA UCMR5 occurrence data downloaded 2026-07-16