Water Quality in Miles City, MT: 15 Violations — Grade D
Grade D · Score 54/100 · 5 water systems · Updated 2026-05-03
Miles City's water has significant violations. Water testing and filtration are recommended.
Data: EPA Safe Drinking Water Information System (SDWIS) Last verified: 2026-05-03
Reviewing EPA compliance files for Miles City, MT surfaces 15 documented water violations — each categorized by violation type and linked to the utility that drew the federal citation.
Water Quality by ZIP Code in Miles City
Water quality varies across Miles City's 1 ZIP codes. Check your specific ZIP for detailed contaminant data.
| ZIP Code | Grade | Score | Violations | Health | |
|---|---|---|---|---|---|
| 59301 | D | 54 | 15 | 3 | View report → |
Violation Trend
EPA violations recorded for water systems serving Miles City.
Water Quality Overview
Miles City, Montana receives a water quality grade of D with an overall score of 54 out of 100, based on EPA compliance data from the Safe Drinking Water Information System (SDWIS).
The 5 water systems serving Miles City have accumulated 15 EPA violations, including 3 health-based violations. These violations are tracked across 1 ZIP codes serving approximately 10,388 people.
What Grade D Means
A grade of D indicates significant compliance issues. Miles City's water systems have accumulated violations that suggest ongoing water quality challenges. Residents should check their specific ZIP code report and consider water testing or filtration.
Lead Levels
The average 90th percentile lead level across Miles City water systems is 0.0030 mg/L — within EPA limits. No ZIP codes exceed the EPA lead action level.
With 81% of homes built before 1986, Miles City has a higher-than-average risk of lead from older plumbing. Lead solder was banned in 1986, and homes built before this date may have lead in pipes, solder joints, or fixtures.
Radon Risk
Miles City is in EPA Radon Zone 1 (High risk). The EPA recommends all homes in Zone 1 areas be tested for radon. Radon is the second leading cause of lung cancer after smoking.
Water Systems Serving Miles City
Miles City is served by 5 community water systems regulated under the Safe Drinking Water Act. These systems collectively serve approximately 10,388 people across 1 ZIP codes.
Each water system is identified by a Public Water System ID (PWSID) and is required to:
- Test for over 90 regulated contaminants on a regular schedule
- Report results to the EPA and state regulators
- Issue an annual Consumer Confidence Report (CCR) to all customers
- Take corrective action when violations occur
The EPA has taken 10 enforcement actions against water systems serving Miles City. Enforcement actions range from informal compliance assistance to formal orders and penalties.
How to Check Your Water in Miles City
Enter your ZIP code on ZipCheckup to see your specific water system data, including contaminant levels, violation history, and safety scores
Request your CCR — your water utility must provide an annual Consumer Confidence Report with detailed test results for all monitored contaminants
Get a home test — certified kits cost $20–$50 and test for lead, bacteria, and common contaminants. Professional lab tests ($150–$400) cover a broader panel
Consider filtration — NSF-certified filters can remove specific contaminants. Reverse osmosis removes the broadest range; activated carbon is effective for chlorine and many organics
Check for advisories — monitor your local utility website and local news for boil water advisories or system alerts
Contaminants Detected in Miles City Water Systems
The following contaminants have been detected or caused violations across Miles City's water systems:
| Contaminant | Category | MCL | Violations | ZIPs Affected | Health-Based |
|---|---|---|---|---|---|
| E. coli | Microbiological | N/A | 4 | 1 | Yes |
| Stage 1 DBP Rule | Treatment Technique | N/A | 2 | 1 | No |
| Total Trihalomethanes (TTHM) | Disinfection Byproducts | 0.08 mg/L | 1 | 1 | No |
| Surface Water Treatment Rule | Treatment Technique | N/A | 1 | 1 | No |
| Total Coliform | Microbiological | N/A | 1 | 1 | No |
MCL = Maximum Contaminant Level (EPA enforceable standard). Health-based violations indicate levels that may pose direct health risks.
Violation Trend Over Time
Year-by-year EPA violations recorded for water systems serving Miles City:
| Year | Total Violations | Health-Based |
|---|---|---|
| 2022 | 6 | 6 |
| 2023 | 1 | 1 |
| 2024 | 2 | 2 |
Violations have decreased from 6 in 2022 to 2 in 2024, indicating improving compliance.
EPA Enforcement History
The EPA and state regulators have taken 10 enforcement actions against water systems serving Miles City. Recent actions:
| Date | Action Type |
|---|---|
| 2025-09-17 | State Informal Action |
| 2025-09-17 | State Informal Enforcement |
| 2025-09-03 | State Order Extension |
| 2025-08-29 | State Order Extension |
| 2025-03-03 | State Order Extension |
| 2025-02-04 | State Informal Action |
| 2024-11-07 | State Informal Action |
| 2024-11-07 | State Informal Enforcement |
| 2024-10-11 | State Order Extension |
| 2024-10-01 | State Informal Action |
Enforcement actions range from informal compliance assistance to formal orders and penalties. The most recent action was on 2025-09-17.
Miles City vs. Nearby Montana Cities
How Miles City's water quality compares to similar cities in Montana:
| City | Grade | Violations | Systems | Population |
|---|---|---|---|---|
| Miles City | D | 15 | 5 | 10,388 |
| Olney | D | 0 | 1 | 10,418 |
| West Yellowstone | C | 4 | 4 | 10,239 |
| Angela | D | 0 | 1 | 9,565 |
Common Questions About Miles City Water
These are the most common questions residents search for about water quality in Miles City, Montana:
Is Miles City water hard or soft? Water hardness varies by source. Miles City's 5 water systems use multiple sources. Check your ZIP code report for specific hardness data.
Can I drink Miles City tap water? Miles City's water receives a grade of D (54/100). There are 3 health-based violations — consider filtration.
What is the best water filter for Miles City? A NSF/ANSI 53-certified filter for lead removal is a good general choice. See our Water Filter Matcher for personalized recommendations.
Miles City vs. Montana Average
Understanding how Miles City compares to the broader Montana average helps contextualize your local water quality. Factors like water source, treatment methods, and infrastructure age all contribute to differences between cities in the same state.
To see how individual neighborhoods compare, check the ZIP code reports below — water quality can vary significantly even within Miles City.
ZIP Codes in Miles City
Miles City spans 1 ZIP code. The ZIP with the lowest water quality score is 59301. Each ZIP code has its own water quality profile based on the specific water system serving that area. Check each ZIP code for detailed contaminant data, violation history, and system information.
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
- Enforcement: EPA ECHO database
- Filter recommendations: NSF/ANSI certified products
Updated daily.