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Our complete water quality ranking grades all 50 U.S. states A–F using EPA data. See which states have the best and worst tap water, each state's average safety score, and the top-ranked city within it. Click any state to explore all cities and detailed water quality data.
Based on the average A–F grade of every city we analyze, the states with the best water quality are Michigan (grade A+, avg 95/100), Minnesota (grade A+, avg 95/100), Missouri (grade A+, avg 95/100), Nebraska (grade A+, avg 95/100), and Nevada (grade A+, avg 95/100). These states tend to pair cleaner source water and modern treatment with strong EPA compliance records. See the full ranking of all 39 states below.
A state average blends hundreds of separate water systems, and it says nothing about your home's own plumbing. A home test kit gives you the actual numbers for your tap, so you can pick a filter for what's really in your water instead of guessing.
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Click any state to explore all cities and detailed water quality data
| Rank | State | Avg Score | Grade | Cities | Score Range | Population |
|---|---|---|---|---|---|---|
| #1 | Michigan | 95 | A+ | 3 | 95 - 95 | 4,435,000 |
| #2 | Minnesota | 95 | A+ | 1 | 95 - 95 | 420,000 |
| #3 | Missouri | 95 | A+ | 2 | 95 - 95 | 1,730,000 |
| #4 | Nebraska | 95 | A+ | 1 | 95 - 95 | 500,000 |
| #5 | Nevada | 95 | A+ | 1 | 95 - 95 | 2,300,000 |
| #6 | New Mexico | 95 | A+ | 1 | 95 - 95 | 680,000 |
| #7 | Ohio | 95 | A+ | 5 | 95 - 95 | 4,400,000 |
| #8 | Oklahoma | 95 | A+ | 2 | 95 - 95 | 1,180,000 |
| #9 | Oregon | 95 | A+ | 3 | 95 - 95 | 200,051 |
| #10 | Utah | 95 | A+ | 8 | 95 - 95 | 1,670,000 |
| #11 | Washington | 95 | A+ | 4 | 95 - 95 | 2,430,000 |
| #12 | Wisconsin | 95 | A+ | 1 | 95 - 95 | 820,000 |
| #13 | New York | 93 | A | 5 | 86 - 95 | 11,141,000 |
| #14 | North Carolina | 92 | A | 5 | 86 - 95 | 2,186,176 |
| #15 | Pennsylvania | 91 | A | 4 | 78 - 95 | 2,230,380 |
| #16 | Texas | 88 | A- | 11 | 65 - 97 | 9,176,377 |
| #17 | Alabama | 83 | B+ | 25 | 68 - 96 | 1,710,306 |
| #18 | Arkansas | 83 | B+ | 20 | 69 - 97 | 1,154,104 |
| #19 | Delaware | 83 | B+ | 10 | 59 - 95 | 218,074 |
| #20 | Iowa | 83 | B+ | 25 | 64 - 96 | 1,419,752 |
| #21 | Maine | 83 | B+ | 15 | 69 - 95 | 375,765 |
| #22 | Maryland | 83 | B+ | 35 | 50 - 98 | 2,233,992 |
| #23 | Massachusetts | 83 | B+ | 50 | 54 - 96 | 3,750,253 |
| #24 | Connecticut | 82 | B+ | 25 | 67 - 97 | 1,602,775 |
| #25 | Hawaii | 81 | B+ | 15 | 67 - 92 | 778,599 |
| #26 | Indiana | 81 | B+ | 40 | 46 - 97 | 3,126,303 |
| #27 | Kentucky | 81 | B+ | 30 | 46 - 97 | 1,715,759 |
| #28 | Tennessee | 81 | B+ | 2 | 67 - 95 | 7,922 |
| #29 | California | 80 | B+ | 193 | 44 - 98 | 28,240,268 |
| #30 | Kansas | 80 | B+ | 25 | 48 - 97 | 1,722,561 |
| #31 | Arizona | 79 | B | 40 | 51 - 98 | 5,474,285 |
| #32 | Illinois | 79 | B | 60 | 47 - 98 | 6,321,081 |
| #33 | Alaska | 78 | B | 10 | 56 - 93 | 410,660 |
| #34 | Florida | 78 | B | 96 | 47 - 96 | 8,727,925 |
| #35 | Georgia | 78 | B | 40 | 44 - 96 | 2,901,545 |
| #36 | Idaho | 78 | B | 20 | 66 - 95 | 1,011,043 |
| #37 | Louisiana | 77 | B | 30 | 52 - 96 | 1,708,978 |
| #38 | Virginia | 77 | B | 1 | 77 - 77 | 229,395 |
| #39 | Colorado | 76 | B | 35 | 45 - 96 | 3,675,915 |
Water quality varies significantly by region due to geography, source water, infrastructure age, and environmental factors: