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50-state inverse ranking · EPA SDWIS

Best Drinking Water Quality by State

“Best” here means the lowest share of public water systems with at least one recorded EPA SDWIS violation, a compliance-history rate, not a recommendation to drink or avoid tap water. Only states with ≥25 public systems are eligible so a tiny utility base cannot lead the list.

51.6%
Minnesota lowest rate
88.3%
Eligible-state system rate
50
States (≥25 systems)

The answer

Among states with at least 25 public water systems, Minnesota has the lowest recorded SDWIS system violation rate: 51.6% (3,386 of 6,557 systems). That is a compliance-history metric, not a claim that Minnesota has the safest drinking water.

51.6%
Minnesota system violation rate
88.3%
Eligible-state system rate
50
States in ranking (≥25 systems)
0
States below min-system floor

Lowest recorded violation rates (≥25 systems)

Share of public water systems with at least one EPA SDWIS violation, best-to-worst among eligible states

rate

What this shows Minnesota leads the lowest-rate list at 51.6% among eligible states. Pair with the <a href="/rankings/worst-water-quality-by-state" class="underline">worst-water-quality board</a> for the inverse superlative.

Source EPA Safe Drinking Water Information System (SDWIS) As of 2026-05-15

Eligible states, lowest to highest violation rate

Rate = systems with at least one recorded SDWIS violation ÷ all public water systems. States below the 25-system floor are listed separately because a handful of utilities can produce a misleading 0% rate.

# State Systems With ≥1 violation Recorded rate
1 Minnesota 6,557 3,386 51.6%
2 South Carolina 1,390 908 65.3%
3 Wisconsin 10,988 7,923 72.1%
4 Delaware 460 344 74.8%
5 Maryland 3,215 2,569 79.9%
6 Hawaii 137 110 80.3%
7 Illinois 5,117 4,134 80.8%
8 Michigan 10,959 9,440 86.1%
9 Nebraska 1,309 1,164 88.9%
10 California 7,249 6,464 89.2%
11 Virginia 2,821 2,540 90.0%
12 New Hampshire 2,453 2,212 90.2%
13 Texas 7,351 6,631 90.2%
14 Ohio 4,181 3,781 90.4%
15 South Dakota 654 599 91.6%
16 Georgia 2,382 2,194 92.1%
17 Washington 4,557 4,199 92.1%
18 Nevada 589 545 92.5%
19 Louisiana 1,234 1,142 92.5%
20 Colorado 2,193 2,030 92.6%
21 North Carolina 5,020 4,663 92.9%
22 Vermont 1,357 1,262 93.0%
23 Florida 5,093 4,749 93.2%
24 Maine 1,864 1,744 93.6%
25 Tennessee 762 716 94.0%
26 North Dakota 368 346 94.0%
27 Connecticut 2,332 2,193 94.0%
28 New York 8,098 7,648 94.4%
29 Arkansas 1,016 960 94.5%
30 Wyoming 766 724 94.5%
31 Montana 2,263 2,144 94.7%
32 New Jersey 3,428 3,256 95.0%
33 Iowa 1,795 1,708 95.2%
34 Massachusetts 1,599 1,522 95.2%
35 Missouri 2,823 2,692 95.4%
36 Indiana 3,967 3,799 95.8%
37 Rhode Island 463 444 95.9%
38 Idaho 2,005 1,927 96.1%
39 Mississippi 1,185 1,139 96.1%
40 New Mexico 1,037 1,005 96.9%
41 Pennsylvania 7,701 7,480 97.1%
42 Utah 1,068 1,042 97.6%
43 Alaska 1,326 1,298 97.9%
44 Oklahoma 1,262 1,239 98.2%
45 Arizona 1,493 1,469 98.4%
46 Oregon 2,518 2,481 98.5%
47 Alabama 562 554 98.6%
48 Kentucky 424 420 99.1%
49 Kansas 957 948 99.1%
50 West Virginia 774 770 99.5%

Explore related rankings

Download the SDWIS/UCMR5 state landscape snapshot cited on this page: sdwis-state-landscape.csv (same CSV as /statistics, CC0).

Every figure on PlainWater is rendered directly from EPA SDWIS drinking-water data, no number is typed in by an editor. Eligible states must have ≥25 public systems; rates are computed from EPA SDWIS violation counts, not editorial safety scores. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 2026-05-15.