countyscore

Water Quality · Missouri

Best Water Quality Counties in Missouri 2026

Ranked by EPA drinking water health violations.

Top 10 — Water Quality in Missouri

Score reflects water quality only — not overall county quality.

1Atchison County, MO
86
2Barton County, MO
86
3Bollinger County, MO
86
4Boone County, MO
86
5Buchanan County, MO
86
6Callaway County, MO
86
7Carter County, MO
86
8Christian County, MO
86
9Clark County, MO
86
10Clinton County, MO
86

All Missouri Counties — Water Quality Rankings

115 counties ranked by water quality score. Overall Score shown for context.

#CountyWater Quality ScoreOverall Score
1Atchison County, MO
86
58.3
2Barton County, MO
86
44.6
3Bollinger County, MO
86
54.3
4Boone County, MO
86
39.5
5Buchanan County, MO
86
31.1
6Callaway County, MO
86
39.7
7Carter County, MO
86
57.5
8Christian County, MO
86
38.5
9Clark County, MO
86
55.1
10Clinton County, MO
86
47.7
11Cole County, MO
86
54.8
12Cooper County, MO
86
56.7
13Crawford County, MO
86
40.7
14Dallas County, MO
86
59
15Dent County, MO
86
55.5
16Douglas County, MO
86
60.8
17Grundy County, MO
86
51
18Jackson County, MO
86
35.7
19Johnson County, MO
86
44.9
20Knox County, MO
86
66
21Laclede County, MO
86
43.7
22Linn County, MO
86
61.9
23Macon County, MO
86
52.6
24Madison County, MO
86
46
25Maries County, MO
86
64
26Randolph County, MO
86
49.9
27Schuyler County, MO
86
55.5
28Shannon County, MO
86
61.3
29St. Charles County, MO
86
48.2
30St. Louis city, MO
86
26.2
31St. Louis County, MO
86
36.6
32Worth County, MO
86
59.2
33Wright County, MO
86
64.2
34Greene County, MO
69.5
54.4
35Cape Girardeau County, MO
69
42.6
36Jasper County, MO
65.8
32
37Livingston County, MO
61.2
52.7
38Ray County, MO
59.8
42.2
39Polk County, MO
59.6
44.3
40Marion County, MO
58.3
42.3
41Pulaski County, MO
58.3
49.8
42Platte County, MO
56.3
45.2
43Barry County, MO
52.1
45.9
44Jefferson County, MO
50.5
40.4
45Warren County, MO
50.3
43.2
46Camden County, MO
49.9
48.6
47Butler County, MO
49.5
37.9
48Phelps County, MO
49.5
43
49Vernon County, MO
48.3
42
50Newton County, MO
47
42.6
51Lafayette County, MO
46.9
56.2
52Moniteau County, MO
46.7
59.1
53Perry County, MO
46.2
47.2
54Taney County, MO
46.1
42.2
55Oregon County, MO
45.8
60
56Audrain County, MO
45.5
51.2
57Ripley County, MO
45
49.8
58Daviess County, MO
44.7
53.5
59Osage County, MO
44
67.2
60Howell County, MO
43.8
49.1
61Adair County, MO
42.8
44.3
62Saline County, MO
42.4
42.8
63Montgomery County, MO
42
53.4
64St. Clair County, MO
41
59.1
65Dade County, MO
39.7
44.1
66Webster County, MO
39.2
50
67Franklin County, MO
38.6
42.5
68Howard County, MO
38.4
52.4
69Benton County, MO
38.2
50.4
70Dunklin County, MO
38.1
40.9
71Cass County, MO
37.1
33.2
72Gasconade County, MO
36.9
59.2
73Lewis County, MO
36.2
62.1
74Stone County, MO
35.4
52.2
75Carroll County, MO
34.6
58.1
76Clay County, MO
34.5
45.5
77McDonald County, MO
33.8
44.7
78Washington County, MO
32.6
51.4
79Putnam County, MO
32.2
62.9
80Reynolds County, MO
30
66.2
81Stoddard County, MO
29.3
47.1
82Nodaway County, MO
28.4
50.3
83Andrew County, MO
28.1
53.8
84Miller County, MO
27.5
54.3
85Pemiscot County, MO
25.5
34.6
86Texas County, MO
25.4
50.3
87Pettis County, MO
24.9
41.1
88Henry County, MO
24.5
44.5
89Lawrence County, MO
24.2
45.6
90Sullivan County, MO
24.1
62.4
91Scott County, MO
22.9
54
92Wayne County, MO
22.7
50
93Harrison County, MO
22.2
50.3
94New Madrid County, MO
20.3
38.1
95Ralls County, MO
19.9
61.9
96Ste. Genevieve County, MO
19.9
54
97Cedar County, MO
19.2
45.4
98Chariton County, MO
19.1
61.3
99Holt County, MO
18.2
57.5
100Mississippi County, MO
18.1
35.4
101Hickory County, MO
17.5
57.8
102St. Francois County, MO
16.7
37.3
103Pike County, MO
16.1
54.6
104Shelby County, MO
14.2
60.1
105Ozark County, MO
11.4
60.2
106Lincoln County, MO
11.1
45
107Caldwell County, MO
10.9
64.7
108DeKalb County, MO
10
55.9
109Bates County, MO
9.6
45.2
110Morgan County, MO
9.5
53.7
111Scotland County, MO
8.4
60.6
112Gentry County, MO
7.1
57.1
113Iron County, MO
5.5
59.3
114Monroe County, MO
4.6
58.6
115Mercer County, MO
4.3
62.8

Explore More

Best overall counties in MissouriFull Water Quality data on WaterByCounty