Wyoming Tap Water Quality Report

116 cities analyzed • 369,505 people served

Updated March 2026 • Data from EWG & EPA SDWIS

116

Cities Analyzed

7.7

Avg Above Guidelines

369,505

Total Population Served

Best Water Quality

Wilson (0 above guidelines)

Most Concerns

Casper (18 above guidelines)

Most Common Contaminants in Wyoming

Contaminant	Found In	% of Cities
Total trihalomethanes (TTHMs) carcinogen	84 of 116	72%
Nitrate and nitrite carcinogen	80 of 116	69%
Haloacetic acids (HAA5) carcinogen	79 of 116	68%
Fluoride	72 of 116	62%
Bromodichloromethane carcinogen	63 of 116	54%
Chloroform carcinogen	61 of 116	53%
Dibromochloromethane carcinogen	58 of 116	50%
Dibromoacetic acid	56 of 116	48%
Bromochloroacetic acid	51 of 116	44%
Uranium carcinogen	47 of 116	41%

City-by-City Water Quality Rankings

Ranked by number of contaminants above EWG health guidelines (most to fewest).

#	City	Detected	Above Guidelines	Above Legal	People Served
1	Casper	27	18	0	59,000
2	Laramie	24	17	0	30,899
3	Farmington Hills	24	17	0	345
4	Cheyenne	23	15	0	64,165
5	Gillette	23	15	0	32,222
6	Rock Springs	22	15	0	24,000
7	Green River	22	15	0	10,500
8	Bar Nunn	19	15	0	4,000
9	Midwest	19	15	0	410
10	Edgerton	19	15	0	195
11	F.e. Warren Afb	23	15	0	0
12	Douglas	19	14	0	6,400
13	Sacramento	19	14	0	475
14	Fort Laramie	17	14	0	0
15	Riverton	33	13	0	10,330
16	Mills	18	13	0	4,050
17	Hartville	14	13	0	0
18	Burlington	15	13	0	0
19	Yellowstone National Park	16	12	1	7,675
20	Torrington	15	12	0	6,847
21	Fort Collins	17	12	0	1,186
22	Moorcroft	14	12	0	1,009
23	Wheatland	17	12	0	0
24	Glendo	14	12	0	0
25	Sinclair	15	12	0	0
26	Manville	12	12	0	0
27	Bairoil	12	12	0	0
28	Thermopolis	15	11	0	3,009
29	Lyman	14	11	0	2,000
30	Hudson	13	11	0	460
31	East Thermopolis	15	11	0	254
32	Charlotte	16	11	0	115
33	Dubois	14	11	0	68
34	Hanna	14	11	0	0
35	Wright	18	10	0	2,500
36	Glenrock	11	10	0	2,466
37	Lusk	13	10	0	1,576
38	Superior	15	10	0	336
39	La Barge	14	10	0	0
40	Burns	14	10	0	0
41	Chugwater	15	10	0	0
42	Sheridan	16	9	0	22,700
43	Mountain View	15	9	0	1,728
44	Basin	13	9	0	1,250
45	Big Piney	12	9	0	445
46	Little America	11	9	0	0
47	Dixon	13	9	2	0
48	Baggs	12	9	0	0
49	Evanston	15	8	0	12,000
50	Powell	11	8	0	6,310
51	Pinedale	11	8	0	1,900
52	Alpine	9	8	0	1,500
53	Sundance	8	8	0	1,279
54	Bear River	15	8	0	1,200
55	Rock River	10	8	0	211
56	Centennial	14	8	1	150
57	Shell	11	8	0	120
58	Lingle	11	8	1	95
59	Granger	11	8	0	0
60	Albin	10	8	0	0
61	Cody	9	7	0	9,836
62	Greybull	11	7	0	3,260
63	Rolling Hills	11	7	0	450
64	Pavillion	9	7	0	300
65	Rawlins	9	7	0	200
66	Lander	9	7	0	65
67	Kemmerer	11	7	0	39
68	Frannie	9	7	0	0
69	Wamsutter	10	7	0	0
70	Deaver	9	7	0	0
71	Saratoga	9	7	0	0
72	Byron	9	7	0	0
73	Jackson	8	6	0	9,800
74	Moose	7	6	0	4,514
75	Shoshoni	9	6	0	650
76	Hulett	6	6	0	420
77	Osage	12	6	0	240
78	Yoder	7	6	0	131
79	Encampment	8	6	0	130
80	Newcastle	10	5	0	3,521
81	Jeffrey City	7	5	0	0
82	Medicine Bow	8	5	0	0
83	Teton Village	8	5	0	0
84	Worland	5	4	0	990
85	Sioux Falls	6	4	0	50
86	Kirby	4	4	0	40
87	La Grange	7	4	0	0
88	Elk Mountain	6	4	0	0
89	Upton	5	3	0	1,100
90	Dayton	4	3	0	824
91	Marbleton	6	3	0	780
92	Thayne	4	3	0	366
93	Meeteetse	5	3	0	35
94	Smoot	5	3	0	0
95	Lance Creek	7	3	1	0
96	Hyattville	5	3	0	0
97	Kaycee	3	3	0	0
98	Ranchester	5	2	0	950
99	Etna	2	2	0	465
100	Lovell	5	2	0	150
101	Clearmont	3	2	0	142
102	Opal	3	2	0	65
103	Jamestown	2	2	0	53
104	Cowley	5	2	0	0
105	Cedaredge	2	1	0	375
106	Grover	2	1	0	252
107	Afton	1	1	0	250
108	Evansville	3	1	0	125
109	Auburn	1	1	0	0
110	Ten Sleep	3	1	0	0
111	Cokeville	2	1	0	0
112	Fairview	2	1	0	0
113	Wilson	2	0	0	1,400
114	Point Of Rocks	2	0	0	78
115	Moran	1	0	0	50
116	Buffalo	1	0	0	29

Recommended Filtration for Wyoming

Based on the most common contaminants found across Wyoming (Total trihalomethanes (TTHMs), Nitrate and nitrite, Haloacetic acids (HAA5)), we recommend a reverse osmosis system or high-quality carbon block filter to remove disinfection byproducts and their precursors.

Echo RO System

Removes up to 99.9% of contaminants. The gold standard for drinking water in Wyoming homes.

View RO Systems

Echo Whole-Home Filter

Protect every tap in your home from chlorine, VOCs, and disinfection byproducts.

View Whole-Home Filters

Echo Hydrogen Water Flask

Once your water is clean, supercharge it with molecular hydrogen for antioxidant and anti-inflammatory benefits.

Shop Hydrogen Flask

Frequently Asked Questions

Is Wyoming tap water safe to drink?

Water quality varies significantly across Wyoming. Of the 116 cities analyzed, the average city has 7.7 contaminants above EWG health guidelines. The best water quality was found in Wilson. We recommend checking your specific city's report for detailed information.

What city has the best water in Wyoming?

Based on our analysis, Wilson has the fewest contaminants above EWG health guidelines in Wyoming, with 0 above guideline levels.

What city has the worst water in Wyoming?

Based on our analysis, Casper has the most contaminants above EWG health guidelines in Wyoming, with 18 above guideline levels.

What's the best water filter for Wyoming residents?

For most Wyoming households, we recommend a reverse osmosis (RO) system for drinking water and a whole-home filter for showers and baths. The specific recommendation depends on your city's contaminant profile — check your city's report for personalized guidance.

National Water Quality Reports

Data sources: Environmental Working Group (EWG) Tap Water Database, U.S. EPA Safe Drinking Water Information System (SDWIS)

Last updated: March 2026

Methodology: Contaminant levels are compared against both EPA legal limits (Maximum Contaminant Levels) and EWG health guidelines, which are often stricter and based on the latest scientific research.

Wyoming Water Quality Report (2026)