2026 Rankings

Worst Infrastructure: Idaho — 2026 Rankings

Last updated: October 15, 2026

265 ZIP codes ranked by Infrastructure Stress Indicator #1: ZIP 83846 (Mullan, ID) - 66/100

Out of 265 ZIP codes with infrastructure data in Idaho, these areas have the highest modeled infrastructure stress indicator values, computed from area-level data on infrastructure age, funding gaps, violation history, and lead indicators. The indicator is not a measured failure probability or forecast.

Statistic Value
ZIP codes ranked 265
Highest stress indicator 66/100
Median stress indicator 43/100
Average stress indicator 41/100
State Idaho

Top 100 ZIP Codes by Infrastructure Stress

Rank ZIP Code City State Infrastructure Stress Stress Level Safety Score
1 83846 Mullan ID 66/100 Very High —
2 83548 Reubens ID 64/100 Very High —
3 83214 Arimo ID 63/100 Very High —
4 83438 Parker ID 63/100 Very High —
5 83874 Murray ID 63/100 Very High —
6 83802 Avery ID 62/100 Very High —
7 83806 Bovill ID 62/100 Very High —
8 83244 Howe ID 61/100 Very High —
9 83254 Montpelier ID 61/100 Very High —
10 83261 Paris ID 61/100 Very High —
11 83523 Craigmont ID 61/100 Very High —
12 83546 Pierce ID 61/100 Very High —
13 83234 Downey ID 60/100 High —
14 83526 Ferdinand ID 60/100 High —
15 83533 Greencreek ID 60/100 High —
16 83849 Osburn ID 60/100 High —
17 83855 Potlatch ID 60/100 High —
18 83867 Silverton ID 60/100 High —
19 83873 Wallace ID 60/100 High —
20 83213 Arco ID 59/100 High —
21 83218 Basalt ID 59/100 High —
22 83241 Grace ID 59/100 High —
23 83311 Albion ID 59/100 High —
24 83334 Hansen ID 59/100 High —
25 83346 Oakley ID 59/100 High —
26 83454 Ucon ID 59/100 High —
27 83262 Pingree ID 58/100 High —
28 83271 Rockland ID 58/100 High —
29 83325 Eden ID 58/100 High —
30 83443 Ririe ID 58/100 High —
31 83522 Cottonwood ID 58/100 High —
32 83824 Desmet ID 58/100 High —
33 83868 Smelterville ID 58/100 High 67/100
34 83210 Aberdeen ID 57/100 High —
35 83239 Georgetown ID 57/100 High —
36 83344 Murtaugh ID 57/100 High —
37 83420 Ashton ID 57/100 High —
38 83435 Monteview ID 57/100 High —
39 83530 Grangeville ID 57/100 High —
40 83545 Peck ID 57/100 High —
41 83672 Weiser ID 57/100 High —
42 83834 Harvard ID 57/100 High —
43 83276 Soda Springs ID 56/100 High —
44 83436 Newdale ID 56/100 High —
45 83464 Leadore ID 56/100 High —
46 83837 Kellogg ID 56/100 High 67/100
47 83220 Bern ID 55/100 High —
48 83848 Nordman ID 55/100 High —
49 83235 Ellis ID 54/100 High —
50 83636 Letha ID 54/100 High —
51 83810 Cataldo ID 54/100 High —
52 83277 Springfield ID 53/100 High —
53 83348 Picabo ID 53/100 High —
54 83320 Carey ID 51/100 High —
55 83543 Nezperce ID 51/100 High —
56 83827 Elk River ID 51/100 High —
57 83263 Preston ID 50/100 High 79/100
58 83661 Payette ID 50/100 High —
59 83252 Malad City ID 49/100 High —
60 83434 Menan ID 49/100 High —
61 83537 Kendrick ID 49/100 High —
62 83544 Orofino ID 49/100 High —
63 83870 Tensed ID 49/100 High —
64 83211 American Falls ID 48/100 High —
65 83223 Bloomington ID 48/100 High —
66 83808 Calder ID 48/100 High —
67 83842 Medimont ID 48/100 High —
68 83255 Moore ID 47/100 High —
69 83286 Weston ID 47/100 High —
70 83431 Lewisville ID 47/100 High —
71 83535 Juliaetta ID 47/100 High —
72 83655 New Plymouth ID 47/100 High —
73 83850 Pinehurst ID 47/100 High —
74 83871 Troy ID 47/100 High —
75 83217 Bancroft ID 46/100 High —
76 83228 Clifton ID 46/100 High —
77 83232 Dayton ID 46/100 High —
78 83250 Mccammon ID 46/100 High —
79 83272 Saint Charles ID 46/100 High —
80 83314 Bliss ID 46/100 High —
81 83342 Malta ID 46/100 High —
82 83450 Terreton ID 46/100 High —
83 83451 Teton ID 46/100 High —
84 83540 Lapwai ID 46/100 High —
85 83555 Winchester ID 46/100 High —
86 83612 Council ID 46/100 High —
87 83623 Glenns Ferry ID 46/100 High —
88 83823 Deary ID 46/100 High —
89 83861 Saint Maries ID 46/100 High —
90 83287 Fish Haven ID 45/100 High —
91 83312 Almo ID 45/100 High —
92 83322 Corral ID 45/100 High —
93 83328 Filer ID 45/100 High —
94 83335 Hazelton ID 45/100 High —
95 83349 Richfield ID 45/100 High —
96 83352 Shoshone ID 45/100 High —
97 83423 Dubois ID 45/100 High —
98 83425 Hamer ID 45/100 High —
99 83444 Roberts ID 45/100 High —
100 83465 Lemhi ID 45/100 High —

Methodology

Infrastructure stress rankings combine four data sources, each weighted equally (25%): (1) EPA Drinking Water Infrastructure Needs Survey and Assessment (DWINSA 2023) — state-level 20-year infrastructure need per capita for pipe replacement, treatment, and storage; (2) Census ACS housing vintage — percentage of homes built before 1980; (3) EPA SDWIS violation and enforcement data — system-level compliance history; (4) available Lead and Copper Rule indicators — service line material inventories and testing results. The combined value is a normalized 0-100 comparative stress indicator, not a measured pipe-failure probability or a forecast.

Data sources: EPA DWINS 2023, Census ACS, EPA SDWIS, Lead and Copper Rule data. Last updated: 2026-10-15.

Frequently Asked Questions

What does the infrastructure stress indicator mean?

The indicator summarizes infrastructure funding gaps, housing age, violation history, and lead indicators on a 0-100 scale. It is a comparative heuristic, not a measured pipe-failure probability or a forecast of a water-main break.

How is infrastructure stress calculated?

The indicator combines four equally weighted factors: state-level infrastructure need per capita (EPA DWINSA 2023), housing vintage (Census ACS pre-1980 housing percentage), water system compliance history (EPA SDWIS), and available lead indicators.

What can homeowners do about aging infrastructure?

Ask your water utility or health department about testing your tap water, especially for lead. Check if your home has a lead service line through your water utility. If you use a filter, choose one certified under NSF/ANSI 53 for the specific contaminant, such as lead. Review your water system Consumer Confidence Report for violation history.

Does high stress mean my water is unsafe right now?

Not necessarily. Infrastructure stress is a screening indicator of long-term vulnerability, not a measurement of current contamination or a prediction of failure. For current conditions, check utility notices and the latest Consumer Confidence Report, and test your tap for contaminants of concern.

Explore More Rankings

How this ranking is calculated, data sources, and limitations: Rankings Methodology →


Related Rankings

Water Safety 2026 EPA violations and water quality scores Lead Risk 2026 Lead service-line indicators and system-level action-level exceedances Infrastructure 2026 Aging pipes, system age and remediation costs
Disclaimer: Rankings are based on EPA, FEMA, and federal agency data. They reflect historical patterns and risk indicators, not necessarily current conditions. For the most current information, contact your local water utility or request a Consumer Confidence Report.

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