Water Quality in Boulder, MT: 2 Violations — Grade D
Grade D · Score 54/100 · 1 water system · Updated 2026-05-03
Boulder's water has significant violations. Water testing and filtration are recommended.
Data: EPA Safe Drinking Water Information System (SDWIS) Last verified: 2026-05-03
According to EPA filings, Boulder, MT has 2 water compliance violations on record — sourced from SDWIS, the federal database that tracks reportable events for every registered public water system in the state.
Water Quality by ZIP Code in Boulder
Water quality varies across Boulder's 1 ZIP codes. Check your specific ZIP for detailed contaminant data.
| ZIP Code | Grade | Score | Violations | Health | |
|---|---|---|---|---|---|
| 59632 | D | 54 | 2 | 1 | View report → |
Water Quality Overview
Boulder, 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 1 water system serving Boulder have accumulated 2 EPA violations, including 1 health-based violation. These violations are tracked across 1 ZIP codes serving approximately 1,400 people.
What Grade D Means
A grade of D indicates significant compliance issues. Boulder'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
Lead testing data for Boulder is currently being collected. The EPA requires all community water systems to test for lead under the Lead and Copper Rule.
With 61% of homes built before 1986, Boulder 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
Boulder 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 Boulder
Boulder is served by 1 community water system regulated under the Safe Drinking Water Act. These systems collectively serve approximately 1,400 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 7 enforcement actions against water systems serving Boulder. Enforcement actions range from informal compliance assistance to formal orders and penalties.
How to Check Your Water in Boulder
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 Boulder Water Systems
The following contaminants have been detected or caused violations across Boulder's water systems:
| Contaminant | Category | MCL | Violations | ZIPs Affected | Health-Based |
|---|---|---|---|---|---|
| E. coli | Microbiological | N/A | 1 | 1 | Yes |
| Total Trihalomethanes (TTHM) | Disinfection Byproducts | 0.08 mg/L | 1 | 1 | No |
MCL = Maximum Contaminant Level (EPA enforceable standard). Health-based violations indicate levels that may pose direct health risks.
EPA Enforcement History
The EPA and state regulators have taken 7 enforcement actions against water systems serving Boulder. Recent actions:
| Date | Action Type |
|---|---|
| 2025-01-23 | State Informal Action |
| 2025-01-23 | State Informal Enforcement |
| 2025-01-23 | State Order Extension |
| 2022-07-28 | State Informal Enforcement |
| 2022-07-28 | State Informal Action |
| 2022-07-28 | State Order Extension |
| 2022-07-28 | State Informal Action |
Enforcement actions range from informal compliance assistance to formal orders and penalties. The most recent action was on 2025-01-23.
Boulder vs. Nearby Montana Cities
How Boulder's water quality compares to similar cities in Montana:
| City | Grade | Violations | Systems | Population |
|---|---|---|---|---|
| Boulder | D | 2 | 1 | 1,400 |
| Cameron | D | 0 | 1 | 1,400 |
| Chinook | D | 6 | 2 | 1,400 |
| Mc Allister | D | 0 | 1 | 1,400 |
Common Questions About Boulder Water
These are the most common questions residents search for about water quality in Boulder, Montana:
Is Boulder water hard or soft? Water hardness varies by source. Boulder's 1 water system uses a single source. Check your ZIP code report for specific hardness data.
Can I drink Boulder tap water? Boulder's water receives a grade of D (54/100). There are 1 health-based violations — consider filtration.
What is the best water filter for Boulder? A NSF/ANSI 53-certified filter for lead removal is a good general choice. See our Water Filter Matcher for personalized recommendations.
Boulder vs. Montana Average
Understanding how Boulder 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 Boulder.
ZIP Codes in Boulder
Boulder spans 1 ZIP code. The ZIP with the lowest water quality score is 59632. 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.