Loading water data...
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 EPA-record score of every city we can grade (health-based violations, lead results, PFAS monitoring — see the methodology), the states with the best water quality are New Mexico (grade A, avg 100/100), Virginia (grade A, avg 100/100), Arkansas (grade A, avg 99/100), Hawaii (grade A, avg 99/100), and Oklahoma (grade A, avg 99/100). 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.
Which states have the worst water quality? The lowest state averages are New York (grade C, avg 72/100), Florida (grade C, avg 77/100) and Arizona (grade B, avg 81/100). A low state average means several graded cities lost points for health-based EPA violations, lead results or PFAS detections — it does not mean every city in the state is unsafe. Check the city grade where you live.
A state average blends hundreds of separate water systems, and it says nothing about your home's own plumbing. Even in a top-graded state, lead and copper can leach from your home's own pipes after the water reaches your street — which no statewide score can capture.
Simplest protection regardless of your state's grade
ZeroWater 10-Cup Pitcher
NSF 53 certified to reduce lead & chromium — no installation, so it's the easiest way to catch anything your home's pipes add after the water leaves the treatment plant, whatever your state's average.
Check Price on AmazonWe may earn a commission from Amazon when you purchase through our links, at no extra cost to you.
Click any state to explore all cities and detailed water quality data
| Rank | State | Avg Score | Grade | Cities | Score Range | Population |
|---|---|---|---|---|---|---|
| #1 | New Mexico | 100 | A | 1 | 100 - 100 | 560,326 |
| #2 | Virginia | 100 | A | 1 | 100 - 100 | 233,655 |
| #3 | Arkansas | 99 | A | 18 | 90 - 100 | 1,336,100 |
| #4 | Hawaii | 99 | A | 4 | 98 - 100 | 911,693 |
| #5 | Oklahoma | 99 | A | 2 | 98 - 100 | 1,057,000 |
| #6 | Tennessee | 99 | A | 2 | 97 - 100 | 1,437,653 |
| #7 | Michigan | 98 | A | 3 | 97 - 100 | 1,074,175 |
| #8 | Minnesota | 97 | A | 1 | 97 - 97 | 425,300 |
| #9 | Missouri | 97 | A | 2 | 95 - 98 | 1,664,295 |
| #10 | Wisconsin | 97 | A | 1 | 97 - 97 | 626,000 |
| #11 | Iowa | 96 | A | 24 | 72 - 100 | 1,470,797 |
| #12 | Nevada | 96 | A | 1 | 96 - 96 | 1,539,277 |
| #13 | Colorado | 94 | A | 35 | 64 - 100 | 4,742,845 |
| #14 | Maine | 94 | A | 11 | 74 - 100 | 363,476 |
| #15 | Indiana | 93 | A | 32 | 59 - 100 | 2,918,159 |
| #16 | Kentucky | 93 | A | 23 | 71 - 100 | 2,544,635 |
| #17 | Oregon | 93 | A | 3 | 79 - 100 | 1,042,020 |
| #18 | Utah | 93 | A | 7 | 84 - 100 | 1,007,311 |
| #19 | Louisiana | 91 | A | 22 | 57 - 100 | 1,949,658 |
| #20 | Massachusetts | 91 | A | 48 | 57 - 100 | 3,750,575 |
| #21 | Idaho | 90 | A | 20 | 70 - 100 | 1,056,251 |
| #22 | Illinois | 90 | A | 56 | 55 - 100 | 6,217,785 |
| #23 | Kansas | 90 | A | 20 | 55 - 100 | 1,341,797 |
| #24 | Alaska | 89 | B | 10 | 73 - 100 | 400,096 |
| #25 | California | 89 | B | 163 | 34 - 100 | 26,652,064 |
| #26 | Nebraska | 89 | B | 1 | 89 - 89 | 660,000 |
| #27 | Washington | 89 | B | 4 | 74 - 100 | 2,327,316 |
| #28 | Maryland | 88 | B | 15 | 64 - 100 | 4,521,145 |
| #29 | Connecticut | 87 | B | 18 | 71 - 100 | 1,939,787 |
| #30 | Delaware | 87 | B | 9 | 74 - 100 | 246,287 |
| #31 | Georgia | 86 | B | 27 | 33 - 100 | 4,367,870 |
| #32 | North Carolina | 85 | B | 5 | 72 - 100 | 2,858,679 |
| #33 | Ohio | 85 | B | 5 | 74 - 99 | 4,005,101 |
| #34 | Pennsylvania | 84 | B | 4 | 69 - 100 | 2,624,001 |
| #35 | Alabama | 82 | B | 22 | 52 - 100 | 2,565,357 |
| #36 | Texas | 82 | B | 11 | 68 - 96 | 11,353,130 |
| #37 | Arizona | 81 | B | 37 | 44 - 100 | 5,364,504 |
| #38 | Florida | 77 | C | 87 | 21 - 100 | 12,503,302 |
| #39 | New York | 72 | C | 5 | 29 - 98 | 9,160,569 |
Water quality varies significantly by region due to geography, source water, infrastructure age, and environmental factors: