US States Water Quality Rankings
Explore water quality data for all 50 US states. States are ranked by average water quality score based on EPA SDWIS data for 187 public water systems.
1
Maryland
MD · 1,400 systems · 6.2M people
100 A
2
South Dakota
SD · 600 systems · 0.9M people
100 A
3
Oregon
OR · 1,400 systems · 4.2M people
98 A
4
Alaska
AK · 600 systems · 0.7M people
97 A
5
North Dakota
ND · 500 systems · 0.8M people
97 A
6
Indiana
IN · 1,800 systems · 6.8M people
96 A
7
Iowa
IA · 1,300 systems · 3.2M people
95 A
8
Nevada
NV · 800 systems · 3.1M people
95 A
9
Louisiana
LA · 1,300 systems · 4.7M people
94 A
10
New Jersey
NJ · 1,800 systems · 9.3M people
94 A
11
New Mexico
NM · 900 systems · 2.1M people
94 A
12
Arkansas
AR · 1,100 systems · 3.0M people
93 A
13
Mississippi
MS · 1,000 systems · 3.0M people
93 A
14
Wisconsin
WI · 1,900 systems · 5.9M people
93 A
15
Arizona
AZ · 1,900 systems · 7.3M people
92 A
16
Georgia
GA · 2,400 systems · 10.8M people
92 A
17
Ohio
OH · 2,700 systems · 11.8M people
92 A
18
Rhode Island
RI · 400 systems · 1.1M people
92 A
19
Delaware
DE · 300 systems · 1.0M people
90 A
20
Kansas
KS · 1,000 systems · 2.9M people
90 A
21
Maine
ME · 800 systems · 1.4M people
90 A
22
Hawaii
HI · 500 systems · 1.4M people
89 B
23
Massachusetts
MA · 1,600 systems · 6.9M people
89 B
24
Nebraska
NE · 900 systems · 2.0M people
89 B
25
Texas
TX · 6,200 systems · 29.5M people
89 B
26
Pennsylvania
PA · 3,200 systems · 13.0M people
88 B
27
Florida
FL · 4,100 systems · 21.8M people
87 B
28
Minnesota
MN · 2,100 systems · 5.7M people
87 B
29
New York
NY · 3,800 systems · 19.8M people
87 B
30
Wyoming
WY · 400 systems · 0.6M people
87 B
31
Kentucky
KY · 1,200 systems · 4.5M people
86 B
32
Michigan
MI · 2,500 systems · 10.1M people
86 B
33
Tennessee
TN · 2,000 systems · 6.9M people
86 B
34
California
CA · 7,500 systems · 39.2M people
85 B
35
Illinois
IL · 2,800 systems · 12.7M people
85 B
36
Montana
MT · 700 systems · 1.1M people
85 B
37
West Virginia
WV · 800 systems · 1.8M people
85 B
38
Virginia
VA · 2,100 systems · 8.6M people
84 B
39
Alabama
AL · 1,400 systems · 5.1M people
82 B
40
Missouri
MO · 1,700 systems · 6.2M people
81 B
41
Oklahoma
OK · 1,100 systems · 4.0M people
81 B
42
Connecticut
CT · 900 systems · 3.6M people
80 B
43
South Carolina
SC · 1,500 systems · 5.3M people
80 B
44
North Carolina
NC · 2,300 systems · 10.5M people
79 B
45
Washington
WA · 2,200 systems · 7.7M people
76 B
46
Idaho
ID · 800 systems · 1.9M people
74 B
47
Colorado
CO · 1,600 systems · 5.8M people
72 B
48
Utah
UT · 900 systems · 3.3M people
65 C
49
Vermont
VT · 500 systems · 0.6M people
60 C
50
New Hampshire
NH · 700 systems · 1.4M people
58 C