Chinook, MT: 4 Health Violations — 49/100 (2026)
1 ZIP code · 2 water systems · Updated 2026-06-03
Drinking water quality in Chinook has lagged behind MT benchmarks — documented violations keep the safety grade low.
How Chinook Compares
Data: EPA SDWIS Last verified: 2026-06-03
What You Should Know About Chinook Water
- Your city's water systems recorded 6 violations in the past 5 years.
- Average lead level: 0.002 mg/L.
- Homes built before 1986: 88% — older plumbing may contain lead solder.
- Estimated remediation: $3,000 per household.
- CDC health risk index: 15.42 — above typical levels.
Who Supplies Your Water in Chinook
Chinook, MT draws its residential water from 2 separate providers among the 2 federally tracked systems. Each operates independently, with its own infrastructure, rate structure, and compliance record.
Overview
We track water quality and home safety data for 1 ZIP code in Chinook, Montana, covering 2 community water systems serving approximately 2,281 people.
1 of 1 ZIP code (100%) have recorded EPA violations. 4 health-based violations documented.
Home Safety Score
Average Home Safety Score for Chinook: D (49/100)
The score combines three factors:
| Factor | What It Measures |
|---|---|
| Water Quality | EPA violations and compliance history |
| Lead Levels | 90th percentile lead concentration vs EPA action level |
| Radon Risk | EPA radon zone classification |
Water Sources
Chinook water systems draw from: Surface water.
Lead & Copper
- Average lead level (90th percentile): 0.0020 mg/L (EPA action level: 0.015 mg/L)
- 0 ZIP codes exceed the EPA lead action level
Radon Risk
Dominant radon zone: Zone 1 (High Risk)
The EPA recommends testing homes in Zone 1 and Zone 2 areas for radon.
Top Contaminants
| Contaminant | Category | Violations | ZIPs Affected |
|---|---|---|---|
| Total Trihalomethanes (TTHM) | Disinfection Byproducts | 8 | 1 |
| Surface Water Treatment Rule | Treatment Technique | 4 | 1 |
Areas with Most Violations
| ZIP Code | Safety Score | Violations | Health-Based | System |
|---|---|---|---|---|
| 59523 | D | 6 | 4 | City of Chinook |
All ZIP Codes in Chinook
- 59523 [D] — 6 violations ⚠
Data Sources
- Water quality: EPA Safe Drinking Water Information System (SDWIS)
- Lead/copper: EPA Lead and Copper Rule sampling data
- Radon: EPA Map of Radon Zones
Updated daily.
Health Outcomes in Chinook
Source: CDC PLACES (County-level estimates). Water contamination can correlate with respiratory and chronic health conditions.
Compared to National Average
Vertical line = national average. ■ Above national · ■ Below national
Top Contaminants in Chinook Water
Based on EPA violation records. Check your ZIP code report for system-specific contaminant data.
Housing & Infrastructure in Chinook
With 88% of homes built before 1986, lead solder in plumbing is a potential concern. The EPA banned lead solder in 1986, but many older homes retain original plumbing.
Source: U.S. Census Bureau American Community Survey (ACS).
Housing Age Profile
What does a median build year of 1951 mean for water safety in Chinook? It means the majority of the city's residential plumbing was installed before 1986, when lead solder was federally banned, and a large share may predate 1970, when lead pipes were commonly used — making plumbing age a central variable in household-level lead risk across much of the city.
Over half of homes in Chinook were built before 1986, when lead solder was banned. Older plumbing may leach lead into drinking water, especially with corrosive water chemistry.
Source: U.S. Census Bureau ACS B25034.
Cost Context: What Remediation Means for Chinook Homeowners
Homeowners in Chinook are working with a moderate equity share for documented remediation — the commitment deserves a line in the household budget, not dismissal.
Remediation costs are moderate relative to home values in Chinook. The estimated $1,900–$4,800 range is manageable for most homeowners but still worth budgeting for. Home values are 32% below the Montana average.
Lead Exposure Risk for Children in Chinook
Why children are most at risk: The CDC states there is no safe level of lead exposure for children. Children under 6 absorb lead more readily than adults, and even low levels can cause developmental delays, learning difficulties, and behavioral problems.
Practically, the structural drivers in Chinook — 88% pre-rule stock and citywide monitoring at or beyond the regulatory benchmark — make an in-home draw the practical way to translate aggregate averages into the specific conditions at one address.
Sources: EPA Lead and Copper Rule, U.S. Census Bureau ACS, CDC childhood lead poisoning prevention guidelines.
Flood & Climate Risk in Chinook
Flood exposure in Chinook is meaningful by NFIP measures — 17 claims on record and 100% of ZIP codes carrying FEMA flood zone designations. That level of activity makes flood history a relevant factor when evaluating local water quality over time.
Chinook has a moderate flood history with 17 FEMA claims averaging $891 per payout. 100% of ZIP codes fall within FEMA flood zones. Flood events can contaminate drinking water and overwhelm treatment systems.
How flooding affects water quality: Flood events can introduce sewage, agricultural runoff, and industrial chemicals into water supplies. Even after floodwaters recede, contamination can persist in wells and aging infrastructure. Flood damage can add significantly to the estimated <strong>$3,000</strong> remediation cost per household.
Residents in flood-prone areas should consider flood insurance even outside FEMA zones — over 25% of flood claims come from low-to-moderate risk areas. After any flood event, test your water before drinking.
Source: FEMA National Flood Insurance Program (NFIP) claims data, FEMA flood zone designations.
What You Can Do in Chinook
- Test your water at home. City-level data shows averages — your tap may differ. NSF-certified test kits cost $20-40 and give results in days.
- Install a certified water filter. Filters rated for Total Trihalomethanes (TTHM) can reduce the most common contaminant found in Chinook's water.
- Check your home's plumbing. With 88% of homes built before 1986, lead solder is a real possibility.
- Review your water system's CCR. Your utility publishes an annual Consumer Confidence Report with detailed test results. Request it or find it online.
Deep Dive Reports
Detailed analysis for Chinook, MT