Montana Tap Water Quality (2026)

Montana Tap Water Quality Report

224 cities analyzed • 561,954 people served

Updated September 2026 • Data from EWG & EPA SDWIS

224

Cities Analyzed

6.3

Avg Above Guidelines

561,954

Total Population Served

Best Water Quality

Shelby (0 above guidelines)

Most Concerns

Fort Benton (13 above guidelines)

Most Common Contaminants in Montana

Contaminant	Found In	% of Cities
Nitrate and nitrite carcinogen	177 of 224	79%
Fluoride	141 of 224	63%
Total trihalomethanes (TTHMs) carcinogen	125 of 224	56%
Haloacetic acids (HAA5) carcinogen	116 of 224	52%
Uranium carcinogen	109 of 224	49%
Bromodichloromethane carcinogen	106 of 224	47%
Chloroform carcinogen	103 of 224	46%
Dibromochloromethane carcinogen	99 of 224	44%
Dibromoacetic acid	94 of 224	42%
Bromochloroacetic acid	91 of 224	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	Billings	23	13	0	114,000
2	Helena	24	13	0	31,005
3	Colstrip	19	13	0	2,350
4	Columbus	16	13	0	1,900
5	Manhattan	17	13	0	1,800
6	Orem	17	13	0	800
7	Ryegate	17	13	0	270
8	Huntley	17	13	0	240
9	Bridger	20	13	0	50
10	Yellowtail	15	13	0	40
11	Fort Harrison	24	13	0	25
12	Fort Benton	14	13	0	0
13	Missoula	24	12	0	68,200
14	Great Fall	23	12	0	60,000
15	Sidney	12	12	0	5,000
16	Hardin	20	12	0	3,500
17	Cutbank	15	12	0	3,105
18	Forsyth	16	12	0	2,260
19	Roundup	15	12	0	1,900
20	Black Eagle	23	12	0	1,233
21	Dallas	16	12	0	650
22	Miles City	16	12	0	480
23	Cut Bank	15	12	0	478
24	Kevin	15	12	0	275
25	Port Orchard	14	12	0	100
26	Ramsay	12	12	0	97
27	Rapelje	15	12	0	70
28	El Dorado Hills	23	12	0	60
29	Boulder	13	12	0	0
30	Malmstrom Air Force Base	24	12	0	0
31	Saco	14	12	0	0
32	Emigrant	15	12	0	0
33	Laurel	13	11	0	6,339
34	Superior	13	11	0	1,100
35	Scobey	14	11	0	1,026
36	Ashland	14	11	0	650
37	Joliet	16	11	0	600
38	Lincoln	16	11	0	530
39	Sun River	14	11	0	525
40	Fromberg	14	11	0	500
41	Hysham	13	11	0	262
42	Wilsall	14	11	0	250
43	Westby	14	11	0	172
44	Carter	16	11	0	150
45	Chinook	15	11	0	100
46	Geraldine	13	11	0	50
47	Denton	14	11	0	0
48	Bozeman	22	10	0	56,000
49	Havre	15	10	0	9,921
50	Hamilton	12	10	0	5,085
51	Glendive	17	10	0	5,000
52	Dillon	11	10	0	4,300
53	Glasgow	15	10	0	3,253
54	East Helena	11	10	0	2,114
55	Red Lodge	11	10	0	2,000
56	Three Forks	15	10	0	1,900
57	Harlotwon	15	10	0	1,050
58	Fort Peck	14	10	0	903
59	Chester	13	10	0	870
60	Ft. Peck	14	10	0	663
61	Cascade	15	10	0	650
62	Virginia City	11	10	0	500
63	Power	12	10	0	89
64	Basin	10	10	0	0
65	Choteau	10	10	0	0
66	Flaxville	13	10	0	0
67	Butte	17	9	0	33,000
68	Livingston	12	9	0	7,500
69	Culbertson	12	9	0	3,005
70	Conrad	16	9	0	2,500
71	Plentywood	12	9	0	1,700
72	Plains	10	9	0	1,500
73	Fairview	13	9	0	1,000
74	White Sulphur Springs	11	9	0	1,000
75	Pinesdale	16	9	0	750
76	Lodge Grass	13	9	0	480
77	Broadus	11	9	0	450
78	St Marie	10	9	0	450
79	Nashua	11	9	0	300
80	Medicine Lake	12	9	0	300
81	Roberts	13	9	0	300
82	Froid	12	9	0	225
83	San Diego	12	9	0	200
84	Warm Springs	12	9	0	171
85	Sweet Grass	10	9	0	100
86	Ledger	15	9	0	95
87	Baker	13	9	0	85
88	Bainville	12	9	0	0
89	Antelope	12	9	0	0
90	Highwood	11	9	0	0
91	Big Sandy	11	9	0	0
92	Kalispell	16	8	0	20,008
93	Anaconda	12	8	0	6,750
94	Seeley Lake	10	8	0	1,375
95	Philipsburg	12	8	0	1,360
96	Hinsdale	10	8	0	250
97	Stockett	12	8	0	210
98	Winnett	11	8	0	187
99	Fairfield	11	8	0	0
100	Loma	15	8	0	0
101	Dutton	12	8	0	0
102	Absarokee	11	8	0	0
103	Brady	10	8	0	0
104	Clyde Park	13	8	0	0
105	Whitefish	12	7	0	10,418
106	Circle	8	7	1	644
107	Broadview	11	7	0	200
108	Paradise	8	7	0	150
109	Corpus Christi	9	7	0	87
110	Neihart	9	7	0	45
111	Big Sky	11	6	0	450
112	Sunburst	10	6	0	434
113	Joplin	9	6	0	225
114	Polson	6	5	0	4,700
115	Thompson Falls	10	5	0	1,600
116	Great Falls	6	5	0	1,500
117	St Ignatius	7	5	0	600
118	Worden	7	5	0	450
119	Moore	9	5	0	186
120	Ballantine	7	5	0	75
121	Big Timber	8	5	0	60
122	Jackson	7	5	1	38
123	Richey	9	5	1	0
124	Belgrade	4	4	0	10,460
125	Deer Lodge	6	4	0	2,900
126	Ronan	6	4	0	2,483
127	Stevensville	7	4	0	2,090
128	Townsend	6	4	0	2,000
129	Deerlodge	7	4	0	1,600
130	Whitehall	7	4	1	1,500
131	Ennis	6	4	0	1,200
132	Columbia Falls	6	4	0	800
133	Somers	6	4	0	600
134	Twin Bridges	7	4	0	424
135	Clancy	5	4	0	350
136	Sand Coulee	7	4	0	200
137	Libby	6	4	0	160
138	Opheim	6	4	0	111
139	Zortman	6	4	0	50
140	E Helena	7	4	0	50
141	Manhattan Mt	8	4	0	40
142	Melstone	5	4	0	0
143	Lolo	6	3	0	3,015
144	Lakeside	7	3	0	1,025
145	Sheridan	4	3	0	632
146	Belt	4	3	0	600
147	Vaughn	8	3	0	585
148	Valier	4	3	0	452
149	Ekalaka	7	3	0	400
150	Eagle	5	3	0	260
151	Frenchtown	5	3	0	250
152	Hailey	6	3	0	200
153	Alberton	5	3	0	85
154	Alder	5	3	0	75
155	Fortine	8	3	0	75
156	Wolf Creek	4	3	1	67
157	Lewistown	5	3	1	56
158	Battle Ground	8	3	0	55
159	Gardiner	7	3	0	52
160	Turner	6	3	1	50
161	Bismarck	4	3	1	30
162	Eureka	5	3	0	30
163	Potomac	3	3	0	25
164	Pendroy	4	3	0	0
165	Corvallis	5	3	0	0
166	Charlo	7	3	0	0
167	Belfry	6	3	0	0
168	Roy	6	3	0	0
169	Pablo	2	2	0	1,375
170	Bend	2	2	0	499
171	Stanford	7	2	0	425
172	Coeur D'alene	2	2	0	300
173	Lima	2	2	0	279
174	Melville	5	2	0	150
175	Judith Gap	3	2	0	126
176	Ulm	3	2	0	105
177	Outlook	3	2	0	96
178	Sevierville	4	2	0	75
179	Heron	3	2	0	60
180	Campbell	7	2	0	54
181	Gallatin Gateway	4	2	0	50
182	Harlem	5	2	0	42
183	Bonner	3	2	0	41
184	Meridian	5	2	0	35
185	Rollins	2	2	0	24
186	Greycliff	4	2	0	0
187	Winifred	3	2	0	0
188	Grass Range	5	2	0	0
189	Augusta	4	2	0	0
190	Rexford	5	2	0	0
191	Dodson	4	2	0	0
192	West Yellowstone	6	1	0	1,364
193	Martin City	1	1	0	885
194	Hot Springs	7	1	0	530
195	Bigfork	2	1	0	485
196	Jordan	2	1	0	364
197	Noxon	1	1	0	250
198	Trout Creek	1	1	0	235
199	Lambert	4	1	0	150
200	Plevna	2	1	0	130
201	Hobson	2	1	0	125
202	Gildford	3	1	0	80
203	Troy	2	1	0	80
204	Musselshell	2	1	0	75
205	Haugan	2	1	0	70
206	Florence	1	1	0	65
207	West Glacier	7	1	0	60
208	Malta	2	1	0	47
209	St Regis	1	1	0	45
210	Sugar City	1	1	0	28
211	Darby	1	1	0	0
212	Geyser	5	1	0	0
213	Coram	1	1	0	0
214	Wibuax	5	1	0	0
215	Cooke City	4	1	0	0
216	Loring	3	1	0	0
217	Shelby	7	0	0	3,970
218	Martinsdale	2	0	0	150
219	Galata	2	0	0	125
220	Harlowton	1	0	0	100
221	Rudyard	1	0	0	75
222	Ethridge	0	0	0	70
223	Marion	0	0	0	70
224	Two Dot	2	0	0	0

Recommended Filtration for Montana

Based on the most common contaminants found across Montana (Nitrate and nitrite, Fluoride, Total trihalomethanes (TTHMs)), 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 Montana 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 Montana tap water safe to drink?

Water quality varies significantly across Montana. Of the 224 cities analyzed, the average city has 6.3 contaminants above EWG health guidelines. The best water quality was found in Shelby. We recommend checking your specific city's report for detailed information.

What city has the best water in Montana?

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

What city has the worst water in Montana?

Based on our analysis, Fort Benton has the most contaminants above EWG health guidelines in Montana, with 13 above guideline levels.

What's the best water filter for Montana residents?

For most Montana 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: September 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.

Montana Water Quality Report (2026)