PFAS Contamination in Montana: 7 ZIP Codes Tested
7 ZIPs tested · 0 exceeding limits (0%)
Data source: EPA UCMR 3/5, SDWIS, ECHO, DOD Last verified: 2026-06-03
PFAS Contamination Summary
| Metric | Value |
|---|---|
| ZIP codes with PFAS detections | 7 |
| ZIP codes exceeding EPA limits | 0 (0%) |
| Superfund sites | 19 |
| Military bases linked to PFAS | 2 of 9 |
| Testing coverage | 2% of state ZIP codes |
| Untested ZIP codes | 381 |
Most Common PFAS Compounds Detected
| Compound | ZIP Codes with Detections |
|---|---|
| PFOS | 4 |
| PFHxS | 3 |
| PFBS | 2 |
| PFBA | 1 |
Worst-Affected Areas in Montana
The following ZIP codes have the highest number of PFAS detections in Montana:
| Rank | ZIP Code | City | PFAS Types | Total Detections | Exceeds EPA Limit |
|---|---|---|---|---|---|
| 1 | 59405 | Great Falls | 1 | 4 | No |
| 2 | 59901 | Kalispell | 2 | 3 | No |
| 3 | 59903 | Kalispell | 2 | 3 | No |
| 4 | 59904 | Kalispell | 2 | 3 | No |
| 5 | 59716 | Big Sky | 1 | 1 | No |
| 6 | 59840 | Hamilton | 1 | 1 | No |
| 7 | 59937 | Whitefish | 1 | 1 | No |
Check your ZIP code on our PFAS map to see if your area is affected.
Sources of PFAS Contamination in Montana
PFAS contamination in Montana comes from several key sources:
Military Installations
2 military bases in Montana are linked to PFAS contamination, primarily from the use of aqueous film-forming foam (AFFF) in firefighting training exercises.
Superfund Sites
Montana has 19 Superfund sites that may contribute to PFAS contamination. Major sites include:
- MOUAT INDUSTRIES
- LOCKWOOD SOLVENT GROUND WATER PLUME
- BILLINGS PCE
- ACM SMELTER AND REFINERY
- CARPENTER SNOW CREEK MINING DISTRICT
Industrial and Municipal Sources
Beyond military and Superfund sites, PFAS contamination in Montana also stems from:
- Industrial facilities that manufactured or used PFAS-containing products
- Airports that used AFFF firefighting foam
- Wastewater treatment plants that received PFAS-laden industrial discharge
- Landfills accepting PFAS-containing consumer products
Montana PFAS Regulations
Montana does not currently have state-specific PFAS drinking water standards. Residents are protected by the federal EPA PFAS rule (April 2024), which sets MCLs of 4 ppt for PFOA and PFOS, with water systems required to comply by 2029.
Some states have moved faster than the federal government. Check our PFAS contaminant guide for the full federal standard and how it compares to state-level action.
Testing Gaps
Only 2% of ZIP codes in Montana have been tested for PFAS. That leaves 381 ZIP codes with no public PFAS data.
The EPA requires all public water systems to complete PFAS monitoring by 2027. Until then, residents in untested areas may want to consider independent water testing or a certified PFAS filter.
What Montana Residents Can Do
1. Check Your Water
Enter your ZIP code on ZipCheckup to see PFAS detections, violations, and health risk scores for your area.
2. Get Your Water Tested
If your ZIP code has PFAS detections or is in an untested area, consider a certified lab test. Look for labs accredited under EPA Method 533 or 537.1. Home test kits cost $150-$350 and cover the six regulated PFAS compounds.
3. Install a Certified Filter
The most effective home treatment options for PFAS removal:
- Reverse osmosis (RO) systems remove 90-99% of PFAS (NSF 58 certified)
- Granular activated carbon (GAC) filters remove 60-95% depending on the compound (NSF 53 certified)
- Ion exchange systems are effective for short-chain PFAS
Use our Filter Matcher tool to find NSF-certified filters that remove PFAS.
4. Check for Lead Risk Too
Many areas with PFAS contamination also face lead service line risks. Use our Lead Risk Calculator to assess your home's lead exposure risk.
Frequently Asked Questions
How many ZIP codes in Montana have PFAS in their water?
Based on EPA data, 7 ZIP codes in Montana have detectable PFAS in their public water supply. Of those, 0 (0%) exceed the federal MCL of 4 ppt for PFOA or PFOS.
Is my water safe to drink in Montana?
It depends on your location. No ZIP codes in Montana currently exceed federal PFAS limits, but detections have been recorded. Enter your ZIP code on ZipCheckup to see your area's specific results. Even if your water meets current standards, you may want to use a certified filter as PFAS accumulate in the body over time.
Does Montana have its own PFAS limits?
Montana does not currently have state-specific PFAS drinking water standards. The federal EPA rule (April 2024) sets MCLs of 4 ppt for PFOA and PFOS, and all public water systems must comply by 2029.
What is the best water filter for PFAS in Montana?
Reverse osmosis (RO) systems certified to NSF 58 are the most effective option, removing 90-99% of PFAS compounds. Granular activated carbon (GAC) filters certified to NSF 53 also reduce PFAS significantly. Use the ZipCheckup Filter Matcher tool to find certified filters for your specific contaminants.
Where does PFAS contamination in Montana come from?
The primary sources include 2 military bases that used AFFF firefighting foam, 19 Superfund sites, industrial facilities, airports, and wastewater treatment plants. PFAS are also found in landfill leachate from consumer products containing these chemicals.
Why hasn't my area been tested for PFAS?
Only 2% of ZIP codes in Montana have public PFAS testing data. The EPA requires all public water systems to complete PFAS monitoring by 2027 under the new federal rule. Until then, you can get independent lab testing (EPA Method 533 or 537.1) for $150-$350.