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WaterSafeCheck

ZIP Code 59523 Water Quality Report

Chinook, MT · Blaine County County

Safety Score
D

Water Safety Grade

Poor — Multiple violations recorded

Health Violations

4

Total Violations

6

Lead Risk

High

Contaminants

1

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Active Water Quality Issues Detected

EPA records show 4 unresolved violations. Contact City of Chinook for current status.

About Tap Water in ZIP Code 59523

Tap water in ZIP code 59523 (Chinook, MT) has received a D grade (score: 49/100) — below average for the nation. City of Chinook has recorded notable violations with EPA Safe Drinking Water Act regulations. Residents may want to consider additional filtration and review their annual Consumer Confidence Report.

Water System

City of Chinook

EPA ID: MT0000174

Water Source

Surface Water

Population Served

1,300 residents

County

Blaine County County, Montana

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Lead Levels in ZIP 59523

EPA action level: 15 ppb | Public health goal: 0 ppb

Lead Level: 2.0 ppb — Very Low

The 90th percentile lead level in 59523 is 2.0 ppb, well below the EPA action level of 15 ppb. While this is a reassuring result, the EPA's public health goal for lead is actually zero — no amount of lead is considered completely safe, particularly for children under 6 and pregnant women. Running your tap for 30 seconds before use and using a certified NSF/ANSI 53 filter adds an extra layer of protection.

Lead exposure risk in 59523 is rated High. EPA models estimate a 65% probability of lead exposure risk in this ZIP code based on housing age, infrastructure age, and water system data. This typically reflects older housing stock built before 1986 (when lead pipes were banned), aging distribution infrastructure, or detected lead levels in water samples. Families should prioritize getting their tap water tested independently and installing a certified lead-reducing filter.

Lead Level (90th percentile)
2.00 ppb (0.002 mg/L)
Lead Exposure Risk Rating
High
Lead Exposure Probability

EPA model estimate based on housing age and infrastructure

65%
Note: Lead levels above are the 90th percentile from EPA monitoring — meaning 90% of samples were at or below this level. Even "undetected" tap water lead doesn't account for lead leaching from home plumbing. If your home was built before 1986, individual tap testing is recommended.
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Violation History

Past 5 years — EPA SDWIS data

City of Chinook has recorded 4 health-based violations in the past 5 years. Multiple health violations suggest recurring compliance challenges. Residents should request a copy of the annual Consumer Confidence Report to understand what contaminants were involved and what corrective actions were taken. 4 violations are currently unresolved — meaning the issue has not yet been formally corrected in EPA records. This is a serious concern that residents should follow up on with their water utility.

Total Violations (5 yr)
6
Health-Based Violations
4
Unresolved Violations
4
Boil Water Advisories
0
Compliance Risk
Critical

Regulatory compliance risk is rated Critical — the highest risk category. City of Chinook has an extensive history of unresolved violations and enforcement actions. Independent water testing is highly recommended.

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Contaminants Detected

Contaminants with health-based violations on record

EPA records identify 1 contaminant associated with health-based violations in ZIP code 59523: Total Trihalomethanes (TTHM). These contaminants exceeded the Maximum Contaminant Levels (MCLs) established by the EPA under the Safe Drinking Water Act at some point in the 5-year monitoring period. The presence of these violations does not necessarily mean water is currently unsafe — water systems are often required to increase monitoring and treatment when violations occur. Review the annual Consumer Confidence Report for the most current status.

Total Trihalomethanes (TTHM)

⚖ Enforcement Actions

10 enforcement actions have been issued against City of Chinook — a high number that reflects sustained compliance struggles. Enforcement actions escalate from administrative orders to financial penalties when utilities repeatedly fail to meet safe drinking water standards.
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Water Source & Environmental Factors

Surface Water

This system draws water from lakes, rivers, or reservoirs. Surface water is treated to remove sediment, microorganisms, and chemical contaminants before reaching taps.

Water Source Type
Surface Water
EPA Radon Zone

Highest potential

Zone 1
Annual Flood Risk Cost

Estimated annual flood-related costs per property

$0
Energy Burden

% of household income spent on energy — indicator of older infrastructure

2.12%

EPA Radon Zone 1 — highest potential for radon in indoor air. Homeowners should test their home for radon and consider mitigation if levels exceed 4 pCi/L.

🛡 What Should You Do? — ZIP 59523 Recommendations

  • 🚨 Install a certified NSF/ANSI 53 or 58 (reverse osmosis) filter immediately for drinking and cooking
  • 🚨 Do not give unfiltered water to children, pregnant women, or immunocompromised individuals
  • 🚨 Contact City of Chinook to request the current violation status and corrective action plan
  • 🚨 Report concerns to your state environmental agency or call the EPA hotline: 1-800-426-4791
  • 🚨 Consider having your home's tap water independently tested by a certified lab

Frequently Asked Questions — ZIP 59523 Water Quality

Is tap water safe to drink in ZIP code 59523?+
Tap water in 59523 has a below-average water quality grade of D. While it is treated, there have been notable compliance issues. We strongly recommend using a certified NSF/ANSI 53 water filter for drinking and cooking, especially for vulnerable populations.
What is the lead level in 59523 tap water?+
The 90th percentile lead level in 59523 is 2.0 ppb (parts per billion). The EPA action level is 15 ppb. This is a low level, well below the EPA action level of 15 ppb.
Who provides tap water to 59523?+
Tap water in ZIP code 59523 is provided by City of Chinook (EPA ID: MT0000174). This system serves approximately 1,300 residents. You can contact them directly for Consumer Confidence Reports, current advisories, and billing information.
What is the water source for 59523?+
ZIP code 59523 is served by surface water. Surface water systems draw from rivers, lakes, or reservoirs and must meet strict EPA treatment requirements including filtration and disinfection.
Does 59523 have any active water quality violations?+
Yes — there are currently 4 unresolved violations on record for this water system. Unresolved violations indicate issues that have not yet been formally corrected in EPA tracking systems. Contact City of Chinook for the latest update.
How do I get a copy of my water quality report for 59523?+
Your water utility — City of Chinook — is required by law to send you an annual Consumer Confidence Report (CCR) by July 1 each year. You can also request it directly from the utility or find it online by searching "City of Chinook Consumer Confidence Report." The EPA's ECHO database also has historical compliance data.
What water filter should I use in 59523?+
The right filter depends on what contaminants are present. For lead, look for a filter certified to NSF/ANSI Standard 53. For chlorine byproducts (like THMs), NSF/ANSI 42 filters work well. For a broad range of contaminants including PFAS, look for NSF/ANSI 58 (reverse osmosis) systems. For ZIP code 59523, with detected contaminants including Total Trihalomethanes (TTHM), a multi-stage filter or reverse osmosis system is recommended.
Is 59523 tap water safe for babies and infants?+
Infants are especially vulnerable to lead, nitrates, and microbial contaminants in drinking water. Current EPA data for 59523 shows a lead level of 2.0 ppb — below the action level, but as an extra precaution, run your tap for 30 seconds before use and consider a certified lead filter for infant formula. Always consult your pediatrician for guidance specific to your child's health.

Data Sources & Methodology

Water quality data for ZIP code 59523 is compiled from the EPA Safe Drinking Water Information System (SDWIS), EPA ECHO enforcement database, UCMR5 unregulated contaminant monitoring, and Consumer Confidence Reports filed by City of Chinook. Safety scores are composite metrics derived from violation history, lead levels, enforcement actions, and infrastructure risk indicators. Data reflects a 5-year monitoring window. Last dataset update: 2024. View EPA source data →