Worst Infrastructure: Montana — 2026 Rankings

Out of 402 ZIP codes with infrastructure data in Montana, these areas face the highest estimated risk of water pipe failure based on infrastructure age, funding gaps, and violation history.

Statistic	Value
ZIP codes ranked	402
Highest risk	64%
Median risk	39%
Average risk	40%
State	Montana

Top 100 Highest Risk ZIP Codes

Rank	ZIP Code	City	State	Pipe Failure Risk	Risk Level	Safety Score
1	59424	Coffee Creek	MT	64%	Very High	40/100
2	59457	Lewistown	MT	62%	Very High	40/100
3	59756	Warm Springs	MT	61%	Very High	54/100
4	59241	Hinsdale	MT	60%	High	41/100
5	59545	Whitlash	MT	59%	High	53/100
6	59547	Zurich	MT	59%	High	53/100
7	59247	Medicine Lake	MT	58%	High	50/100
8	59333	Hathaway	MT	58%	High	40/100
9	59242	Homestead	MT	57%	High	40/100
10	59256	Raymond	MT	57%	High	40/100
11	59301	Miles City	MT	57%	High	54/100
12	59416	Brady	MT	57%	High	55/100
13	59430	Denton	MT	57%	High	45/100
14	59523	Chinook	MT	57%	High	49/100
15	59526	Harlem	MT	57%	High	40/100
16	59933	Stryker	MT	57%	High	40/100
17	59004	Ashland	MT	56%	High	33/100
18	59062	Otter	MT	56%	High	40/100
19	59338	Kinsey	MT	56%	High	53/100
20	59484	Sweet Grass	MT	56%	High	28/100
21	59542	Turner	MT	56%	High	22/100
22	59858	Philipsburg	MT	56%	High	33/100
23	59012	Birney	MT	55%	High	53/100
24	59419	Bynum	MT	55%	High	62/100
25	59420	Carter	MT	55%	High	51/100
26	59433	Dutton	MT	55%	High	65/100
27	59501	Havre	MT	55%	High	44/100
28	59528	Hingham	MT	55%	High	66/100
29	59739	Lima	MT	55%	High	66/100
30	59832	Drummond	MT	55%	High	53/100
31	59257	Redstone	MT	54%	High	40/100
32	59401	Great Falls	MT	54%	High	56/100
33	59724	Dell	MT	54%	High	53/100
34	59035	Fort Smith	MT	53%	High	33/100
35	59038	Hysham	MT	53%	High	56/100
36	59254	Plentywood	MT	53%	High	70/100
37	59327	Forsyth	MT	53%	High	70/100
38	59082	Springdale	MT	52%	High	53/100
39	59231	Saint Marie	MT	52%	High	53/100
40	59414	Black Eagle	MT	52%	High	68/100
41	59442	Fort Benton	MT	52%	High	61/100
42	59642	Ringling	MT	52%	High	40/100
43	59747	Pony	MT	52%	High	40/100
44	59759	Whitehall	MT	52%	High	45/100
45	59024	Custer	MT	51%	High	63/100
46	59312	Angela	MT	51%	High	40/100
47	59425	Conrad	MT	51%	High	55/100
48	59480	Stockett	MT	51%	High	65/100
49	59039	Ingomar	MT	50%	High	53/100
50	59244	Larslan	MT	50%	High	40/100
51	59259	Richey	MT	50%	High	64/100
52	59276	Whitetail	MT	50%	High	40/100
53	59316	Boyes	MT	50%	High	40/100
54	59351	Volborg	MT	50%	High	40/100
55	59427	Cut Bank	MT	50%	High	64/100
56	59474	Shelby	MT	50%	High	64/100
57	59529	Hogeland	MT	50%	High	40/100
58	59711	Anaconda	MT	50%	High	59/100
59	59722	Deer Lodge	MT	50%	High	58/100
60	59867	Saltese	MT	50%	High	40/100
61	59043	Lame Deer	MT	49%	High	40/100
62	59263	Scobey	MT	49%	High	51/100
63	59347	Rosebud	MT	49%	High	53/100
64	59522	Chester	MT	49%	High	64/100
65	59701	Butte	MT	49%	High	63/100
66	59923	Libby	MT	49%	High	62/100
67	59036	Harlowton	MT	48%	High	73/100
68	59059	Musselshell	MT	48%	High	83/100
69	59075	Saint Xavier	MT	48%	High	63/100
70	59214	Brockway	MT	48%	High	40/100
71	59222	Flaxville	MT	48%	High	56/100
72	59248	Nashua	MT	48%	High	43/100
73	59253	Peerless	MT	48%	High	40/100
74	59260	Richland	MT	48%	High	40/100
75	59270	Sidney	MT	48%	High	45/100
76	59315	Bloomfield	MT	48%	High	40/100
77	59330	Glendive	MT	48%	High	66/100
78	59353	Wibaux	MT	48%	High	69/100
79	59446	Geraldine	MT	48%	High	65/100
80	59454	Kevin	MT	48%	High	43/100
81	59461	Lothair	MT	48%	High	40/100
82	59467	Pendroy	MT	48%	High	55/100
83	59525	Gildford	MT	48%	High	55/100
84	59601	Helena	MT	48%	High	42/100
85	59755	Virginia City	MT	48%	High	61/100
86	59003	Ashland	MT	47%	High	33/100
87	59072	Roundup	MT	47%	High	48/100
88	59230	Glasgow	MT	47%	High	39/100
89	59258	Reserve	MT	47%	High	40/100
90	59326	Fallon	MT	47%	High	40/100
91	59468	Power	MT	47%	High	64/100
92	59477	Simms	MT	47%	High	53/100
93	59479	Stanford	MT	47%	High	65/100
94	59482	Sunburst	MT	47%	High	64/100
95	59074	Ryegate	MT	46%	High	81/100
96	59215	Circle	MT	46%	High	64/100
97	59240	Glentana	MT	46%	High	40/100
98	59262	Savage	MT	46%	High	40/100
99	59336	Ismay	MT	46%	High	40/100
100	59418	Buffalo	MT	46%	High	40/100

Methodology

Infrastructure risk rankings combine four data sources, each weighted equally (25%): (1) EPA Drinking Water Infrastructure Needs Survey (DWINS 2023) — state-level 20-year funding gap per capita for pipe replacement, treatment, and storage; (2) Census ACS housing vintage — percentage of homes built before 1980, when lead solder and galvanized pipes were common; (3) EPA SDWIS violation and enforcement data — system-level compliance history; (4) Lead and Copper Rule indicators — service line material inventories and 90th percentile lead testing results. The combined score is normalized to a 0-100% probability scale.

Data sources: EPA DWINS 2023, Census ACS, EPA SDWIS, Lead and Copper Rule data. Last updated: 2026-07-19.

Frequently Asked Questions

What does pipe failure probability mean?

Pipe failure probability estimates the likelihood of water main breaks, lead contamination from corroded pipes, or service disruptions based on infrastructure age, state funding gaps, violation history, and lead indicators. It is not a prediction of imminent failure, but a risk assessment based on known factors.

How is infrastructure risk calculated?

The risk score combines four equally weighted factors: state-level infrastructure funding gap per capita (from EPA DWINS 2023), housing vintage (Census ACS pre-1980 housing percentage), water system violation and enforcement history (EPA SDWIS), and lead exposure indicators (service line probability and testing results).

What can homeowners do about aging infrastructure?

Test your tap water annually, especially for lead. Check if your home has a lead service line through your water utility. Consider a whole-house water filter (NSF/ANSI 53 certified). Review your water system Consumer Confidence Report for violation history.

Does high risk mean my water is unsafe right now?

Not necessarily. Infrastructure risk indicates long-term vulnerability, not current contamination. However, areas with aging pipes and high violation counts have a statistically higher chance of water quality issues. Regular testing is the best way to verify your water safety.