US Water Quality Rankings by State (2026)
All 50 states ranked by population-weighted water quality score. Scores are based on contaminant test results and EPA violation records from the Safe Drinking Water Information System (SDWIS).
| 1 | Minnesota | A (90) | 330 | 4529379 |
| 2 | Michigan | A (87) | 390 | 7336583 |
| 3 | Hawaii | A (83) | 18 | 1489177 |
| 4 | California | A (81) | 584 | 39902288 |
| 5 | Virginia | A (80) | 185 | 7277964 |
| 6 | Delaware | B (79) | 24 | 977709 |
| 7 | Georgia | B (76) | 302 | 10279519 |
| 8 | North Dakota | B (76) | 65 | 673521 |
| 9 | Maryland | B (74) | 81 | 5355810 |
| 10 | Maine | B (72) | 72 | 638125 |
| 11 | Texas | B (72) | 902 | 31521265 |
| 12 | Nebraska | B (70) | 117 | 1568192 |
| 13 | South Dakota | B (70) | 85 | 826874 |
| 14 | Kansas | B (69) | 216 | 2677943 |
| 15 | Missouri | B (69) | 328 | 5466461 |
| 16 | Tennessee | B (69) | 260 | 7829421 |
| 17 | Iowa | B (68) | 268 | 2762707 |
| 18 | Vermont | B (68) | 69 | 392687 |
| 19 | Alabama | B (65) | 322 | 6086402 |
| 20 | Arkansas | B (65) | 266 | 2884505 |
| 21 | Colorado | B (65) | 181 | 6977932 |
| 22 | Indiana | B (64) | 293 | 5102871 |
| 23 | Wyoming | B (64) | 54 | 481630 |
| 24 | Nevada | B (62) | 41 | 3091598 |
| 25 | South Carolina | B (62) | 157 | 4557074 |
| 26 | Wisconsin | B (62) | 334 | 4085357 |
| 27 | Louisiana | B (60) | 259 | 5018767 |
| 28 | Washington | B (60) | 255 | 8893518 |
| 29 | Illinois | C (59) | 632 | 11759030 |
| 30 | Rhode Island | C (59) | 27 | 1050475 |
| 31 | New York | C (58) | 457 | 17830142 |
| 32 | Ohio | C (56) | 410 | 10253021 |
| 33 | Connecticut | C (55) | 46 | 2748432 |
| 34 | Florida | C (55) | 316 | 21683823 |
| 35 | Oregon | C (55) | 175 | 3614578 |
| 36 | West Virginia | C (53) | 162 | 1479022 |
| 37 | North Carolina | C (51) | 302 | 9211368 |
| 38 | New Hampshire | C (51) | 78 | 787352 |
| 39 | Montana | C (50) | 80 | 683882 |
| 40 | Massachusetts | C (45) | 272 | 10003956 |
| 41 | Oklahoma | D (37) | 268 | 3460912 |
| 42 | New Mexico | D (36) | 110 | 1876985 |
| 43 | Kentucky | D (31) | 232 | 4567933 |
| 44 | Pennsylvania | D (31) | 429 | 11157027 |
| 45 | New Jersey | D (30) | 237 | 8813563 |
| 46 | Utah | D (29) | 131 | 3599181 |
| 47 | District of Columbia | D (24) | 1 | 667325 |
| 48 | Idaho | F (18) | 87 | 1446007 |
| 49 | Arizona | F (17) | 120 | 7233891 |
| 50 | Alaska | F (13) | 31 | 609960 |
| 51 | Mississippi | F (7) | 264 | 2997429 |