PFAS in Drinking Water in Montana
What residents of Montana need to know about PFAS ("forever chemicals") in drinking water — including contamination sources, which utilities have documented violations, and how to filter PFAS from tap water.
Source: EPA SDWIS, Montana Department of Environmental Quality, CDC · Last reviewed: 2025-01-01
Quick Answer
Is PFAS in drinking water a real concern in Montana?
PFAS contamination in Montana is primarily associated with Malmstrom AFB near Great Falls and fire training areas at Montana's regional airports. Malmstrom AFB has documented AFFF use and some groundwater contamination monitoring near the installation. Montana's geography — vast distances between communities, many relying on small groundwater systems — means PFAS treatment challenges are especially acute.
Where does PFAS come from in Montana?
Malmstrom AFB in Cascade County near Great Falls is Montana's primary military PFAS source. AFFF firefighting foam at this intercontinental ballistic missile (ICBM) base has contaminated surrounding groundwater in the Great Falls area. Regional airports across Montana — including Billings Logan, Missoula, and Bozeman Yellowstone International — have conducted fire training with AFFF and may have localized PFAS contamination.
What should Montana residents know?
Great Falls area residents near Malmstrom AFB and private well users in Cascade County face the most direct military PFAS risk. Montana's widely dispersed population means many residents rely on small, rural water systems or private wells that receive limited regulatory oversight. Montana DEQ has conducted PFAS testing under UCMR5.
Key Facts
| EPA MCL (PFOA/PFOS) | 4 ppt — effective April 2024 |
| MCLG | Zero |
| Primary contamination source | Malmstrom AFB (Cascade County/Great Falls area) — ICBM base with significant AFFF history |
| Secondary concerns | Regional airport fire training sites (Billings, Missoula, Bozeman) |
| Infrastructure challenge | Small, rural water systems may face resource constraints for PFAS treatment |
| State regulator | Montana Department of Environmental Quality (DEQ) |
| Health effects | Cancer (kidney, testicular), thyroid disruption, immune effects, developmental toxicity |
| Effective treatment | Reverse osmosis (NSF/ANSI 58) or granular activated carbon |
Why PFAS Matters in Montana
Montana's PFAS contamination is less densely concentrated than in more urbanized states, but the scale of Malmstrom AFB — which oversees a large portion of the U.S. ICBM missile field — means extensive AFFF use history near Great Falls. Montana's small rural water systems will face significant resource challenges implementing treatment under the new EPA MCL. The state's important agricultural water use also means that PFAS in irrigation water (from contaminated groundwater) can enter the food supply chain through produce and livestock.
Montana PFAS Regulation
Montana DEQ participates in UCMR5 monitoring for large systems. Malmstrom AFB near Great Falls is the primary PFAS assessment site in the state, with AFFF contamination documented in the immediate base vicinity. Montana's largely rural character and reliance on small water systems means many residents may have limited PFAS monitoring data. Montana follows the federal MCL with no additional state standard.
Largest Montana Water Utilities
No PFAS violations on record in EPA SDWIS for Montana utilities in our database. Browse the largest utilities to review their full water quality record.
What Are PFAS (“Forever Chemicals”)?
PFAS are a family of over 12,000 synthetic chemicals used in non-stick cookware, stain-resistant fabrics, food packaging, and AFFF firefighting foam. Their carbon-fluorine bonds do not break down in the environment or the body — hence the name “forever chemicals.” AFFF used at military bases is the single largest source of PFAS in U.S. drinking water.
Full PFAS overview — national data, health effects, all 50 statesWho Should Pay Closest Attention
Great Falls and Cascade County rural residents near Malmstrom AFB, and private well users in areas near Montana's regional airports with fire training histories, face the most direct PFAS risk. Montana's rural communities may lack the financial resources to implement treatment independently.
Residents near military bases with AFFF use history
Private well owners near military or industrial sites
Pregnant residents and families with young children
Residents in communities with documented PFAS detections
Anyone who has consumed water above 4 ppt for an extended period
Residents near airports, fire training areas, or industrial manufacturers
How to Check Your Situation in Montana
- 1
Identify your water utility using the ZIP lookup below or by browsing the Montana utility directory on this site.
- 2
Review your utility's Consumer Confidence Report (CCR) — it must report PFAS monitoring results under UCMR5 and the new MCL.
- 3
Check the EPA's ECHO database for your utility's monitoring history. Look for PFAS, PFOA, PFOS, and related compound results.
- 4
Contact your utility directly and ask for their most recent PFAS test results and whether they are implementing treatment under the 2024 MCL.
- 5
If you use a private well near a military base, airport, or industrial facility, order a PFAS panel test from a state-certified laboratory. Tests typically cost $150–$400.
- 6
If PFAS is detected above 4 ppt in your source water, install a certified NSF/ANSI 58 reverse osmosis system or an NSF/ANSI 53-certified activated carbon filter rated for PFAS removal.
How to Remove PFAS from Tap Water
Reverse Osmosis (Best)
90–99% removal — NSF/ANSI 58 certified systems only
Certified Activated Carbon
Effective with NSF/ANSI 53 or 58 certification — verify before buying
Boiling concentrates PFAS. Standard pitcher filters and water softeners do not remove PFAS. Always verify NSF certification before purchasing.
Take Action Now
Look up your Montana utility's PFAS monitoring history on the PFAS Watchlist below.
If your utility has detected PFAS above 4 ppt, install an NSF/ANSI 58-certified reverse osmosis system at your drinking tap.
Private well owners near military or industrial sites should order a PFAS panel test ($150–$400 at a state-certified lab).
Request your utility's most recent Consumer Confidence Report — PFAS results must be disclosed under the new 2024 MCL.
Frequently Asked Questions
Related Pages
PFAS — National Overview
All U.S. utilities with PFAS records
Montana PFAS Watchlist
Live utility PFAS monitoring data
Montana State Overview
All utilities and water quality data
Reverse Osmosis Guide
Removes 90–99% of PFAS
Activated Carbon Filter Guide
NSF/ANSI 53/58 certified options for PFAS
Arsenic in Drinking Water
Another priority contaminant
All Contaminants
Complete reference library
Data Sources & Provenance
All data on this page is sourced from official U.S. government or public datasets.
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Montana Department of Environmental Quality ↗