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).

1MinnesotaA (90)3304529379
2MichiganA (87)3907336583
3HawaiiA (83)181489177
4CaliforniaA (81)58439902288
5VirginiaA (80)1857277964
6DelawareB (79)24977709
7GeorgiaB (76)30210279519
8North DakotaB (76)65673521
9MarylandB (74)815355810
10MaineB (72)72638125
11TexasB (72)90231521265
12NebraskaB (70)1171568192
13South DakotaB (70)85826874
14KansasB (69)2162677943
15MissouriB (69)3285466461
16TennesseeB (69)2607829421
17IowaB (68)2682762707
18VermontB (68)69392687
19AlabamaB (65)3226086402
20ArkansasB (65)2662884505
21ColoradoB (65)1816977932
22IndianaB (64)2935102871
23WyomingB (64)54481630
24NevadaB (62)413091598
25South CarolinaB (62)1574557074
26WisconsinB (62)3344085357
27LouisianaB (60)2595018767
28WashingtonB (60)2558893518
29IllinoisC (59)63211759030
30Rhode IslandC (59)271050475
31New YorkC (58)45717830142
32OhioC (56)41010253021
33ConnecticutC (55)462748432
34FloridaC (55)31621683823
35OregonC (55)1753614578
36West VirginiaC (53)1621479022
37North CarolinaC (51)3029211368
38New HampshireC (51)78787352
39MontanaC (50)80683882
40MassachusettsC (45)27210003956
41OklahomaD (37)2683460912
42New MexicoD (36)1101876985
43KentuckyD (31)2324567933
44PennsylvaniaD (31)42911157027
45New JerseyD (30)2378813563
46UtahD (29)1313599181
47District of ColumbiaD (24)1667325
48IdahoF (18)871446007
49ArizonaF (17)1207233891
50AlaskaF (13)31609960
51MississippiF (7)2642997429