Water Quality in Big Arm, MT: No Violations — Grade D
Grade D · Score 40/100 · 1 water system · Updated 2026-05-03
Big Arm's water has significant violations. Water testing and filtration are recommended.
Data: EPA Safe Drinking Water Information System (SDWIS) Last verified: 2026-05-03
Across all available EPA tracking data for Big Arm, MT, the record has remained clean — 1 public water system on file, zero violations recorded, and no enforcement proceedings initiated at any point in the federal dataset.
Water Quality by ZIP Code in Big Arm
Water quality varies across Big Arm's 1 ZIP codes. Check your specific ZIP for detailed contaminant data.
| ZIP Code | Grade | Score | Violations | Health | |
|---|---|---|---|---|---|
| 59910 | D | 40 | 0 | 0 | View report → |
Water Quality Overview
Big Arm, Montana receives a water quality grade of D with an overall score of 40 out of 100, based on EPA compliance data from the Safe Drinking Water Information System (SDWIS).
No EPA violations have been recorded for the 1 water system serving Big Arm. This is a positive indicator, though it does not guarantee the absence of all contaminants — some substances (like PFAS) are not yet fully regulated.
What Grade D Means
A grade of D indicates significant compliance issues. Big Arm'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 Big Arm is currently being collected. The EPA requires all community water systems to test for lead under the Lead and Copper Rule.
Radon Risk
Big Arm 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 Big Arm
Big Arm is served by 1 community water system regulated under the Safe Drinking Water Act. These systems collectively serve approximately 56 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
How to Check Your Water in Big Arm
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
Big Arm vs. Nearby Montana Cities
How Big Arm's water quality compares to similar cities in Montana:
| City | Grade | Violations | Systems | Population |
|---|---|---|---|---|
| Big Arm | D | 0 | 1 | 56 |
| Dayton | D | 0 | 1 | 56 |
| Elmo | D | 0 | 1 | 56 |
| Proctor | D | 0 | 1 | 56 |
Common Questions About Big Arm Water
These are the most common questions residents search for about water quality in Big Arm, Montana:
Is Big Arm water hard or soft? Water hardness varies by source. Big Arm's 1 water system uses a single source. Check your ZIP code report for specific hardness data.
Can I drink Big Arm tap water? Big Arm's water receives a grade of D (40/100). No health-based violations have been recorded, but home testing is always recommended.
What is the best water filter for Big Arm? A NSF/ANSI 53-certified filter for lead removal is a good general choice. See our Water Filter Matcher for personalized recommendations.
Big Arm vs. Montana Average
Understanding how Big Arm 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 Big Arm.
ZIP Codes in Big Arm
Big Arm spans 1 ZIP code. 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.