PFAS in Drinking Water in Idaho
What residents of Idaho 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, Idaho Department of Environmental Quality, CDC · Last reviewed: 2025-01-01
Quick Answer
Is PFAS in drinking water a real concern in Idaho?
PFAS contamination in Idaho is primarily linked to Mountain Home Air Force Base in Elmore County and fire training activities at Gowen Field near Boise. Both installations have documented AFFF use that has contributed PFAS to surrounding groundwater. The extent of off-base contamination is being studied, and Idaho DEQ has expanded monitoring near military sites.
Where does PFAS come from in Idaho?
Mountain Home AFB is the primary known PFAS source in Idaho. The remote location of Mountain Home AFB means off-base contamination primarily affects rural Elmore County private well users and the Mountain Home city water system. Gowen Field's location adjacent to the Boise Airport means potential PFAS exposure in the Treasure Valley's southern groundwater areas.
What should Idaho residents know?
Idaho DEQ has been testing public water systems near military facilities as part of the federal UCMR5 monitoring program. Mountain Home city water customers and private well owners in rural Elmore County near the base should be aware of available monitoring data. The new EPA 4 ppt MCL will determine whether any Idaho systems require treatment installation.
Key Facts
| EPA MCL (PFOA/PFOS) | 4 ppt — effective April 2024 |
| MCLG | Zero |
| Primary contamination sources | Mountain Home AFB (Elmore County), Gowen Field near Boise — AFFF-related |
| Aquifer concern | Snake River Plain Aquifer — major regional groundwater resource |
| State regulator | Idaho 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 certified for PFAS |
Why PFAS Matters in Idaho
Idaho has fewer major PFAS contamination sites than many western states, but Mountain Home AFB represents a documented source. The Snake River Plain Aquifer — Idaho's most important groundwater resource — sits beneath a large portion of the state, and contamination at Mountain Home could affect this aquifer over time. Idaho DEQ has been monitoring the situation and requiring testing under UCMR5. Idaho's large agricultural economy also means some irrigation districts and rural water systems that draw from shallow aquifers could be affected.
Idaho PFAS Regulation
Idaho DEQ participates in EPA UCMR5 monitoring for large systems and has conducted PFAS assessments at Mountain Home AFB and Boise Airport. The state's significant agricultural sector and reliance on Snake River Plain Aquifer groundwater means PFAS from agricultural irrigation with contaminated water is a secondary concern. Idaho follows the federal MCL with no additional state standard.
Largest Idaho Water Utilities
No PFAS violations on record in EPA SDWIS for Idaho 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
Residents of Mountain Home and rural Elmore County near Mountain Home AFB, along with private well owners in the Boise area south of Gowen Field, should prioritize reviewing available PFAS monitoring data. Idaho's significant private well population means many residents receive no regulatory PFAS protection.
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 Idaho
- 1
Identify your water utility using the ZIP lookup below or by browsing the Idaho 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 Idaho 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
Idaho PFAS Watchlist
Live utility PFAS monitoring data
Idaho 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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Idaho Department of Environmental Quality ↗