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Wyoming Water Quality Rankings

63 cities ranked · Data from EPA SDWIS

69.7
State avg score
63
Cities ranked
57%
A or B grade
29%
D or F grade
60
Health violations
15
PFAS detected
Analysis

Wyoming water quality overview

Wyoming's drinking water quality is fair overall, with a state average score of 69.7 out of 100 — 4.8 points below the national average of 74.5. The median city score is 73.6, reflecting how water quality is distributed across the state's 63 ranked cities. The state shows a mixed picture: 19 cities earned an A grade while 9 cities received an F. The majority fall in the B–C range. PFAS "forever chemicals" were detected in 15 of 63 cities (24%). Of those, 2 cities exceed the 2024 EPA maximum contaminant levels — a health concern requiring action. 1 city has lead levels exceeding the EPA action level of 15 ppb, typically a sign of aging lead service lines or lead solder in older plumbing. Residents in these areas should use an NSF 53-certified filter. 60 cities have recorded health-based violations with the EPA — meaning contaminant levels exceeded safe limits or required testing was missed. Use the table below to find your city's specific record.

Grade Distribution

How Wyoming cities scored

30%
27%
14%
14%
14%
A
19
30%
Excellent
B
17
27%
Good
C
9
14%
Fair
D
9
14%
Poor
F
9
14%
Failing
Score Distribution

Score distribution by range

20 10 0
3
9
8
7
11
20
5
0–9
10–19
20–29
30–39
40–49
50–59
60–69
70–79
80–89
90–100
Comparison

State vs national average

C+
Wyoming
69.7/100
B-
National avg
74.5/100
▼ 4.8 pts below national average
City Map

Water quality across Wyoming

Each dot is a city, colored by grade. Size reflects population served. Click any city to view its full report.

Wyoming city water quality map
Water quality: A B C D F
60 cities mapped · hover to preview · click to explore
Highlights

Top & bottom cities in Wyoming

Best 10 cities

  1. 1 A+ Wright 95 3K
  2. 2 A Powell 93.6 6K
  3. 3 A Teton Village 93.4 906
  4. 4 A Upton 90.5 1K
  5. 5 A Ranchester 90.2 1K
  6. 6 A- Byron 89.8 593
  7. 7 A- Worland 89.4 7K
  8. 8 A- Hanna 89.4 841
  9. 9 A- Dayton 88.9 824
  10. 10 A- Glenrock 88.8 2K

Worst 10 cities

  1. 54 F Cheyenne 30.8 78K
  2. 55 F Torrington 36.2 8K
  3. 56 F Riverton 38.7 11K
  4. 57 F Sheridan 41.5 24K
  5. 58 F Mills 41.8 4K
  6. 59 F Fort Washakie 41.8 6K
  7. 60 F Casper 41.8 62K
  8. 61 F Jackson 43.2 27K
  9. 62 F Gillette 44.5 45K
  10. 63 D Thermopolis 45.6 4K
Full Rankings

All 63 cities in Wyoming

# City Grade Score Score Population Violations Issues
1 Wright
A+
 95
3K 8 Unresolved
2 Powell
A
 93.6
6K 3 Unresolved
3 Teton Village
A
 93.4
906 11 Health Unresolved
4 Upton
A
 90.5
1K 7 Health Unresolved
5 Ranchester
A
 90.2
1K 9 Health Unresolved
6 Byron
A-
 89.8
593 8 Unresolved
7 Worland
A-
 89.4
7K 23 Health Unresolved
8 Hanna
A-
 89.4
841 22 Health Unresolved
9 Dayton
A-
 88.9
824 52 Health Unresolved
10 Glenrock
A-
 88.8
2K 8 Health Unresolved
11 Guernsey
A-
 88.8
1K 80 Health Unresolved
12 Moose
A-
 88.3
7K 8 Health Unresolved
13 Shoshoni
A-
 88.1
515 41 Health Unresolved
14 Lyman
A-
 87.9
2K 51 Health Unresolved
15 Mountain View
A-
 87.8
1K 18 Health Unresolved
16 Sundance
A-
 87.7
1K 36 Health Unresolved
17 Wamsutter
A-
 87
500 22 Health Unresolved
18 Cowley
A-
 86.5
800 46 Health Unresolved
19 Smoot
A-
 85.3
720 32 Health Unresolved
20 Basin
B+
 84.3
1K 20 Health Unresolved
21 Lander
B+
 84.2
8K 89 Health Unresolved
22 Evanston
B+
 81.3
12K 44 Health Unresolved
23 Moorcroft
B+
 80.9
1K 23 Health Unresolved
24 Pinedale
B+
 80.6
2K 72 Health Unresolved
25 Encampment
B+
 80.2
580 158 Health Unresolved
26 Star Valley Ranch
B
 78.6
2K 54 Health Unresolved
27 Green River
B
 77.5
11K 40 Health Unresolved
28 Saratoga
B
 77.3
2K 48 Health Unresolved
29 Greybull
B
 77
3K 95 Health Unresolved
30 Lovell
B
 76
3K 44 Health Unresolved
31 Ethete
B-
 74.5
3K 358 Health Unresolved
32 Bedford
B-
 73.6
750 51 Health Unresolved
33 Burns
B-
 73.3
1K 131 Health Unresolved
34 Buffalo
B-
 73.2
4K 65 Health Unresolved
35 Cody
B-
 72
18K 67 Health Unresolved
36 Farson
B-
 72
530 112 Health Unresolved
37 Lusk
C+
 69.9
2K 119 Health Unresolved
38 Little America
C+
 68.7
2K 67 Health Unresolved
39 Wheatland
C+
 66.7
4K 156 Health Unresolved
40 Rock Springs
C
 64.8
30K 132 Health Unresolved
41 Douglas
C
 64.2
7K 95 Health Lead Unresolved
42 Dubois
C
 63.5
2K 168 Health Unresolved
43 Yellowstone Nt
C
 62.1
6K 38 Health Unresolved
44 Rawlins
C-
 56
9K 59 Health Unresolved
45 Laramie
C-
 55.2
34K 120 Health Unresolved
46 Marbleton
D+
 52
861 912 Health Unresolved
47 Alpine
D+
 51.1
2K 213 Health Unresolved
48 Kemmerer
D+
 50.8
3K 58 Health Unresolved
49 Yellowstone Np
D
 50
8K 32 Health Unresolved
50 Afton
D+
 50
2K 391 Health Unresolved
51 Cokeville
D+
 50
535 135 Health Unresolved
52 Wilson
D
 48
536 231 Health Unresolved
53 Newcastle
D
 47
5K 350 Health Unresolved
54 Thermopolis
D
 45.6
4K 130 Health Unresolved
55 Gillette
F
 44.5
45K 1227 Health Unresolved
56 Jackson
F
 43.2
27K 1633 Health Unresolved
57 Casper
F
 41.8
62K 267 Health Unresolved
58 Fort Washakie
F
 41.8
6K 510 Health PFAS Unresolved
59 Mills
F
 41.8
4K 288 Health Unresolved
60 Sheridan
F
 41.5
24K 235 Health Unresolved
61 Riverton
F
 38.7
11K 730 Health PFAS Unresolved
62 Torrington
F
 36.2
8K 211 Health Unresolved
63 Cheyenne
F
 30.8
78K 515 Health Unresolved
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