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WaterVerge

Water quality report · updated Jul 2026

Is Wibaux, MT Tap Water Safe to Drink?

Graded D+, with 25 unresolved violations on record. See what was cited — and what it means for your tap. What to do ↓

0 contaminants over a legal limit
0.0 ppb lead, 90th percentile · low
25 unresolved violations
550 people served by 1 water system

PWSID MT0000361 · moderate data confidence · local government utility

Reviewed by WaterVerge Editorial Team · Last updated July 2026
D 50 / 100

#77 of 110Montana cities
How we grade →

01The verdict: is Wibaux water safe?

Wibaux's drinking water has significant quality concerns based on EPA testing data. With a grade of D+ (50/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 1 water system serves approximately 550 residents using groundwater (wells).

The concern

25 unresolved violations on record

EPA records show open compliance items for this system. Most are administrative, but unresolved items are worth watching.

See what was cited ↓
The good news

Lead is well under the limit

90th-percentile lead is 0.0 ppb — beneath the 15 ppb federal action level and under the 5 ppb watch threshold.

See the trend ↓
Keep watching

107 violations in the last five years

Recent compliance history is the best predictor of future problems — the year-by-year record is below.

See the record ↓

Wibaux's drinking water received a grade of D+ (50 out of 100), indicating poor water quality. The city's 1 water system serves approximately 550 residents using groundwater.

Lead levels were measured at 0.0 ppb (90th percentile), well within EPA limits. This system has not yet been tested for PFAS under the EPA UCMR 5 program. The system has 139 violations on record, including 9 health-based violations. 25 remain unresolved.

Wibaux ranks #77 out of 110 cities in Montana for water quality, placing it below average in the state. Wibaux relies on groundwater, which is generally less vulnerable to surface contamination but can be affected by naturally occurring minerals like arsenic and nitrate, as well as agricultural and industrial runoff. As a small community water system, Wibaux may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities. The system has seen 107 violations in the past five years, suggesting a pattern of compliance challenges that residents should monitor closely.

How the 50/100 breaks down Methodology →
ViolationsHistorical violation record including health-based and monitoring violations.
0 / 45F
Lead & CopperLead at 0.0 ppb (90th percentile).
20 / 20A
ContaminantsPFAS + legacy contaminant analysis.
17 / 20B
ComplianceMonitoring and reporting compliance with EPA regulations.
8 / 10B
Source RiskWater source: Groundwater.
5 / 5A

02What's in Wibaux's water

Every contaminant flagged in Wibaux, on one shared scale: distance to its own legal limit. The red line is the limit — anything past it is out of compliance, and the closer a bar gets, the less headroom the system has.

1 detection · sorted by % of legal limit
Over the limit Elevated — watch Within limits
0 50% LEGAL LIMIT 150%
1 contaminant tested under EPA SDWIS, LCR and UCMR programs · 1 detected · not yet tested for PFAS under UCMR 5

Full contaminants report

Contaminant Detected Level EPA Limit Unit Category Status
Lead (90th percentile) 0.0 15 ppb Inorganic Safe
Data source: EPA SDWIS, UCMR 5, local utility CCR.

03Wibaux's ten-year track record

Each box is one year. A green check means no EPA violations; a numbered badge counts that year's violations — red if any were health-based, amber if they were monitoring or paperwork issues. The system has 139 violations on record, including 9 health-based violations. 25 remain unresolved.

3 of the last ten years were clean. The numbered years had EPA violations — red when any were health-based, amber when they were paperwork or missed-testing issues.

1 health-based in 10 yrs 111 monitoring & paperwork 14 still unresolved
UpdateWater quality data updatedLatest EPA compliance and testing data incorporated into Wibaux's water quality assessment. Grade: D+ (50/100).
Violation1 drinking water violation recordedContaminants: Lead and Copper Rule.Open
Violation1 drinking water violation recordedContaminants: Revised Total Coliform Rule.Resolved
Violation2 drinking water violations recordedContaminants: E. COLI, Nitrate-Nitrite.Open
Lead, 90th percentileppb · lower is better
01020304050EPA action level · 15 ppb1993 — 12 ppb1994 — 11 ppb1995 — 10 ppb1996 — 6 ppb2001 — 9 ppb2007 — 5 ppb2010 — 10 ppb2013 — 8 ppb2016 — 39 ppb2017 — 3 ppb2018 — 3 ppb2023 — 0 ppb12019931996201020172023

Down 12 ppb since 1993. Latest reading: 0 ppb (2023) — 0% of the action level. Sampled at higher-risk homes (90th percentile).

04Where Wibaux's water comes from

Wibaux's drinking water is drawn from underground aquifers through wells.

Source

Groundwater

Underground aquifers reached by wells — naturally filtered, but can carry minerals like arsenic and nitrate.

Treatment

Local treatment

Groundwater generally needs less treatment — typically disinfection and, where needed, mineral removal.

Distribution

1 system

1 water system, operated under local government ownership.

Delivery

550 people

Residents served across Wibaux's service area.

Groundwater is naturally filtered through rock and soil layers, generally requiring less treatment than surface water. However, it can contain naturally occurring contaminants like arsenic, radon, and minerals. Agricultural activity, septic systems, and industrial operations near well fields can introduce nitrates, pesticides, and volatile organic compounds. The system is operated by local government ownership and serves approximately 550 people through 1 water system.

System namePWSIDPopulationSource
WIBAUX TOWN OF MT0000361 550 Groundwater

05Pressure on Wibaux's watershed

Outside forces that shape what reaches the treatment plant. None of these is a verdict on the tap by itself — but each adds pressure worth knowing about.

Drought

D2 — severe drought

Wibaux County is in D2 (severe drought) per the U.S. Drought Monitor (week of Jul 2026). Drought can raise disinfection-byproduct levels and taste/odor issues as utilities draw from lower reservoirs.

Current streak at D2+ severity10 wks
Weeks at D2+ in the last 5 years10 wks
Months in D2+ over the last 30 years11.3%

06How Wibaux compares

Scores for nearby Montana cities on one line, with the average marked.

Wibaux (this city)
50 · D+
Bozeman
43.4 · F
Missoula
42.6 · F
Kalispell
40.1 · F
Billings
39.6 · F
Great Falls
34.5 · F

dashed line = Montana average (48/100)

Wibaux scores 50/100on par with the Montana average of 48/100. It outscores 8 of 10 nearby cities. Full Montana rankings →

Wibaux water quality rankings
Compare all cities in the county — grades, violations, and contaminant data side by side.

07What to do at home

Steps matched to what testing actually found in Wibaux's water — not generic advice.

Extra protection

A basic carbon filter still helps

Wibaux's water meets federal standards, but a simple carbon filter improves taste and adds a margin of safety against short-term issues.

Compare tested filters →
Know your report

Read your utility's annual report

Every utility must publish a yearly Consumer Confidence Report with its own testing results. It pairs well with the independent data on this page.

How to read a CCR →
Stay informed

Watch for Wibaux alerts

We refresh EPA data monthly and surface new violations, advisories, and boil-water notices for your county on this page.

All water alerts →

Frequently asked questions

Is Wibaux, MT tap water safe to drink?

Wibaux's water quality earned a grade of D+ (50/100). Significant issues have been found. A water filter is strongly recommended. The city ranks #77 out of 110 cities tested in Montana.

What contaminants are in Wibaux's water?

Lead was measured at 0.0 ppb (90th percentile). 139 violations are on record.

How is Wibaux's water quality grade calculated?

The grade is based on four factors: violation history (40%), lead and copper levels (25%), PFAS contamination (25%), and regulatory compliance (10%). The score is also adjusted based on how complete the available data is. See our methodology page for full details.

Do I need a water filter in Wibaux?

Based on current data, basic filtration should suffice for additional peace of mind.

Where does Wibaux's water come from?

Wibaux's water is sourced from Groundwater. The city has 1 water system serving approximately 550 residents.

What health violations has Wibaux's water system had?

Wibaux has 9 health-based violations on record. The most recent violation was recorded in October 2025. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 25 violations remain unresolved.

Is Wibaux's groundwater at risk of contamination?

Wibaux uses groundwater, which can be affected by naturally occurring contaminants like arsenic, radon, and nitrate, as well as agricultural runoff and industrial activity. The system has 139 violations on record that may relate to groundwater quality. Groundwater systems are generally less susceptible to surface contamination but should be monitored for emerging contaminants like PFAS.

How does Wibaux's water compare to other cities?

Wibaux ranks #77 out of 110 cities in Montana (better than 30% of state cities) and #12944 out of 15382 cities nationally (16th percentile). The grade of D+ reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.

Does Wibaux's small water system affect quality?

Wibaux's system serves approximately 550 residents. Small community water systems (under 3,300 people) may have fewer financial resources for infrastructure upgrades and advanced treatment technologies. However, they are held to the same EPA drinking water standards as larger systems. This system has 139 violations on record.

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About Wibaux, MT: Median household income $61,042 · median home value $91,416 · median age 51.8 · 82.4% homeowners · 19.2% college educated. Service area: 1 ZIP code across Wibaux.
Show ZIP codes 59353
Sources: EPA SDWIS & ECHO · UCMR 3–5 · Lead & Copper Rule samples · EPA TRI · U.S. Drought Monitor · FEMA declarations. Data last updated Jul 2026. Analysis by the WaterVerge Editorial Team · methodology.