WaterVerge

Is Mountain Home Afb, ID Tap Water Safe to Drink?

Graded D, with 3 unresolved violations on record. See what was cited — and what it means for your tap. What to do next ↓

8K residents served 1 water system PWSID: ID4200054
Overall Score
47.5 / 100
Violations
3 active
Last Updated
May 2026
Source
Groundwater
#107 of 139 in Idaho Top 86% nationally
Federal
High data confidence
Reviewed by WaterVerge Editorial Team · Last updated May 2026
DGRADE
Water Quality Grade
47.5/100
waterverge.com
D 47.5/100

Mountain Home Afb, ID — Water Quality Report

Mountain Home Afb's drinking water received a grade of D (47.5 out of 100), indicating poor water quality. The city's 1 water system serves approximately 7,500 residents using groundwater.

Lead levels were measured at 0.0 ppb (90th percentile), well within EPA limits. UCMR 5 testing detected 4 PFAS compounds in the water supply.

The system has 232 violations on record, including 17 health-based violations. 3 remain unresolved.

Data last updated: May 2026 · Source: EPA SDWIS, UCMR 5
Analysis

What to know about Mountain Home Afb's water

Mountain Home Afb ranks #107 out of 139 cities in Idaho for water quality, placing it among the lowest-rated in the state.

Mountain Home Afb relies on groundwater, which is generally less vulnerable to surface contamination but can be affected by naturally occurring minerals like arsenic and nitrate, as well as agricultural and industrial runoff.

PFAS compounds were detected in testing, though levels remain within current EPA limits. Residents seeking extra precaution may consider an activated carbon or reverse osmosis filter.

The system has seen 111 violations in the past five years, suggesting a pattern of compliance challenges that residents should monitor closely.

Quality Breakdown

Water quality score

See methodology →
47.5 out of 100 Grade D
A: 90-100
B: 74-89
C: 60-73
F: <50
How is this calculated?
Violations
0/45
F
Historical violation record including health-based and monitoring violations.
Lead & Copper
20/20
A
Lead at 0.0 ppb (90th percentile).
Contaminants
12.5/20
C
4 PFAS compounds detected.
Compliance
10/10
A
Monitoring and reporting compliance with EPA regulations.
Source Risk
5/5
A
Water source: Groundwater.
Water Safety

Is Mountain Home Afb, ID water safe to drink?

Concerns Identified

Mountain Home Afb's drinking water has significant quality concerns based on EPA testing data. With a grade of D (47.5/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 1 water system serves approximately 7,500 residents using groundwater (wells).

3
Active Violations
0.0 ppb
Lead (90th %ile)
4 compounds
PFAS Detected

Recent water quality updates for Mountain Home Afb

A timeline of significant water quality events, violations, and data updates.

PFAS
4 PFAS "forever chemical" compounds detected

Detected at levels within current EPA limits. PFAS persist indefinitely in the environment.

Update
Water quality data updated

Latest EPA compliance and testing data incorporated into Mountain Home Afb's water quality assessment. Grade: D (47.5/100).

Violation
1 drinking water violation recorded

Contaminants: Lead and Copper Rule.

Violation
2 drinking water violations recorded

Contaminants: Revised Total Coliform Rule, Chlorine.

Violation
1 drinking water violation recorded

Contaminants: Revised Total Coliform Rule.

Key contaminant findings

Based on the most recent EPA sampling data for Mountain Home Afb's water supply.

Lead Within Limits
Detected: 0.0 ppb Limit: 15 ppb (EPA Action Level)

Well within EPA limits.

PFAS (4 compounds) Elevated
Detected: Highest: PFHxA at 0.0130 µg/L Limit: 0.004 µg/L (EPA MCL)

Detected but within current EPA limits. PFAS do not break down in the environment and can accumulate in the body over time. An activated carbon filter can reduce exposure.

PFAS "forever chemicals" detected

UCMR 5 testing found 4 PFAS compounds in Mountain Home Afb's water supply. PFAS are synthetic chemicals that persist indefinitely in the environment and the human body.

Compound Level EPA MCL Status
PFHxA 0.0130 µg/L 0.004 µg/L Within Limit
PFHxS 0.0100 µg/L 0.004 µg/L Within Limit
PFPeA 0.0067 µg/L 0.004 µg/L Within Limit
PFBS 0.0048 µg/L 0.004 µg/L Within Limit

Violation history

Mountain Home Afb's water system has 232 total violations on record, including 17 health-based violations. 3 remain unresolved. 111 violations were issued in the last 5 years.

MRMONMCL
Most recent violations:
Dec 2025 Lead and Copper Rule Open
Aug 2024 Revised Total Coliform Rule Resolved
Aug 2024 Chlorine Resolved
Mar 2022 Revised Total Coliform Rule Resolved
Jan 2022 Chlorine Resolved

Where does Mountain Home Afb's water come from?

Mountain Home Afb's drinking water comes from groundwater (wells), supplied by 1 water system serving approximately 7,500 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate.

What Mountain Home Afb residents can do

Install a water filter

Recommended: Activated carbon or reverse osmosis filter. This addresses the specific contaminants found in Mountain Home Afb's water.

Request your utility's CCR

Your water utility is required to publish an annual Consumer Confidence Report (CCR) with detailed testing results. Ask for the latest copy or check your utility's website.

Data: EPA SDWIS, UCMR 5 (PFAS), FEMA, NOAA. Last updated May 2026.

Contaminant Alerts

Top contaminants to know

View all ↓
Lead (90th percentile)
Inorganic / Heavy Metal
Safe
0.0 ppb
EPA Action Level: 15 ppb · 0% of limit
Safe Level
PFHxA
PFAS / Forever Chemical
Near MCL
0.0130 µg/L
EPA MCL: 0.004 µg/L · +20% over limit
Detected
PFHxS
PFAS / Forever Chemical
Near MCL
0.0100 µg/L
EPA MCL: 0.004 µg/L · +20% over limit
Detected
PFAS Testing

Forever chemicals overview

National PFAS report →
30
Compounds tested
4
Detected
0
Exceed EPA MCL
Compliance Record

Violation summary

232
Total violations
17
Health-based
3
Active / unresolved
Dec 2025
Most recent violation
Compliance Record

Violations & advisories

232 Total
3 Active
17 Health-based
229 Resolved
Violations by category
Synthetic Organic Chemicals
102
Volatile Organic Chemicals
63
Nitrate Rule
22
Inorganic Chemicals
18
Radionuclides and Revised Rad Rule
6
Dec 2025 Active
Lead and Copper Rule
Monitoring & Reporting
Monitoring & Reporting 0
Nov 2021 Active
E. COLI
Monitoring & Reporting
Monitoring & Reporting 0
Aug 2018 Active
E. COLI
Monitoring & Reporting
Monitoring & Reporting 0
Aug 2024 Resolved
Revised Total Coliform Rule
Monitoring
Monitoring Resolved Aug 2024
Aug 2024 Resolved
Chlorine
Monitoring & Reporting
Monitoring & Reporting Resolved Aug 2024
Mar 2022 Resolved
Revised Total Coliform Rule
Monitoring
Monitoring Resolved Mar 2022
Jan 2022 Resolved
Chlorine
Monitoring & Reporting
Monitoring & Reporting Resolved Mar 2022
Oct 2021 Resolved
Endrin
Monitoring & Reporting
Monitoring & Reporting Resolved Dec 2021
Oct 2021 Resolved
BHC-GAMMA
Monitoring & Reporting
Monitoring & Reporting Resolved Dec 2021
Oct 2021 Resolved
Methoxychlor
Monitoring & Reporting
Monitoring & Reporting Resolved Dec 2021
Oct 2021 Resolved
Toxaphene
Monitoring & Reporting
Monitoring & Reporting Resolved Dec 2021
Oct 2021 Resolved
Dalapon
Monitoring & Reporting
Monitoring & Reporting Resolved Dec 2021
Oct 2021 Resolved
Diquat
Monitoring & Reporting
Monitoring & Reporting Resolved Dec 2021
Oct 2021 Resolved
Endothall
Monitoring & Reporting
Monitoring & Reporting Resolved Dec 2021
Oct 2021 Resolved
OXAMYL
Monitoring & Reporting
Monitoring & Reporting Resolved Dec 2021
Oct 2021 Resolved
Simazine
Monitoring & Reporting
Monitoring & Reporting Resolved Dec 2021
Oct 2021 Resolved
Dinoseb
Monitoring & Reporting
Monitoring & Reporting Resolved Dec 2021
Oct 2021 Resolved
Atrazine
Monitoring & Reporting
Monitoring & Reporting Resolved Dec 2021
Oct 2021 Resolved
LASSO
Monitoring & Reporting
Monitoring & Reporting Resolved Dec 2021
Oct 2021 Resolved
Heptachlor epoxide
Monitoring & Reporting
Monitoring & Reporting Resolved Dec 2021
Showing 20 of 232 violations
Industrial pollution

Top industrial polluters within 10 miles of Mountain Home Afb

Industrial polluters nearby

Reported releases to surface water by facilities near Mountain Home Afb, ranked by pounds discharged annually.

FacilityTop chemicalTo surface water (lbs/yr)Distance
US DOD USAF MOUNTAIN HOME AFB
Other · US DEPARTMENT OF DEFENSE
MOUNTAIN HOME AFB, ID83648
0.3 mi
US DOD USAF SMALL ARMS RANGE
Other · US DEPARTMENT OF DEFENSE
MOUNTAIN HOME AFB, ID83648
0.3 mi

Source: EPA Toxic Release Inventory (TRI) 2023

Site context

Superfund sites within 10 miles of Mountain Home Afb

Superfund sites nearby

Federally tracked hazardous-waste sites on the EPA National Priorities List. Proximity does not necessarily indicate tap-water contamination — the connection depends on hydrology and treatment.

Source: EPA Superfund National Priorities List

Environmental Risk

Drought conditions

D2 — severe drought

Elmore County is currently in D2 (severe drought) per the U.S. Drought Monitor (week of May 5, 2026). Drought can elevate disinfection-byproduct (TTHM/HAA5) levels and taste/odor issues as utilities draw from lower reservoirs.

6
Weeks at D2+ (current streak)
30.9%
Months in D2+ (last 30y)
6
Weeks at D2+ (last 5y)

Source: U.S. Drought Monitor, updated weekly by NDMC, USDA, and NOAA.

Recommended water filters

Based on contaminants detected in Mountain Home Afb's water supply, we recommend the following filter types.

🧪
For PFAS
Reverse Osmosis or Activated Carbon Block
4 PFAS compounds detected

Full contaminants report

Contaminant Detected Level EPA Limit Unit Category Status
Lead (90th percentile) 0.0 15 ppb Inorganic Safe
11Cl-PF3OUdS ND HI µg/L PFAS Not Detected
4:2 FTS ND HI µg/L PFAS Not Detected
6:2 FTS ND HI µg/L PFAS Not Detected
8:2 FTS ND HI µg/L PFAS Not Detected
9Cl-PF3ONS ND HI µg/L PFAS Not Detected
ADONA ND HI µg/L PFAS Not Detected
HFPO-DA ND 0.01 µg/L PFAS Not Detected
lithium ND HI µg/L PFAS Not Detected
NEtFOSAA ND HI µg/L PFAS Not Detected
NFDHA ND HI µg/L PFAS Not Detected
NMeFOSAA ND HI µg/L PFAS Not Detected
PFBA ND HI µg/L PFAS Not Detected
PFBS 0.005 HI µg/L PFAS Detected
PFDA ND HI µg/L PFAS Not Detected
PFDoA ND HI µg/L PFAS Not Detected
PFEESA ND HI µg/L PFAS Not Detected
PFHpA ND HI µg/L PFAS Not Detected
PFHpS ND HI µg/L PFAS Not Detected
PFHxA 0.013 HI µg/L PFAS Detected
PFHxS 0.010 HI µg/L PFAS Detected
PFMBA ND HI µg/L PFAS Not Detected
PFMPA ND HI µg/L PFAS Not Detected
PFNA ND HI µg/L PFAS Not Detected
PFOA ND 0.004 µg/L PFAS Not Detected
PFOS ND 0.004 µg/L PFAS Not Detected
PFPeA 0.007 HI µg/L PFAS Detected
PFPeS ND HI µg/L PFAS Not Detected
PFTA ND HI µg/L PFAS Not Detected
PFTrDA ND HI µg/L PFAS Not Detected
PFUnA ND HI µg/L PFAS Not Detected
Data source: EPA SDWIS, UCMR 5, local utility CCR.

Lead level trend (90th percentile)

EPA action level: 15 ppb
Lead has decreased by 2.0 ppb from 1992 (2.0 ppb) to 2025 (0.0 ppb).
Contaminant Rankings

See how Mountain Home Afb compares by contaminant

Explore where Mountain Home Afb ranks among all Idaho cities for specific contaminants.

Infrastructure

Water source & infrastructure

Primary Source
Groundwater
Operator
Federal
Population Served
7,500
Water Systems
1
Water Source

Where Mountain Home Afb's water comes from

Groundwater

Mountain Home Afb's drinking water is drawn from underground aquifers through wells.

Groundwater is naturally filtered through rock and soil layers, generally requiring less treatment than surface water. However, it can contain naturally occurring contaminants like arsenic, radon, and minerals.

Agricultural activity, septic systems, and industrial operations near well fields can introduce nitrates, pesticides, and volatile organic compounds.

The system is operated by federal ownership and serves approximately 7,500 people through 1 water system.

Infrastructure

Water systems serving Mountain Home Afb

System Name PWSID Population Source
MOUNTAIN HOME AIR FORCE BASE ID4200054 7,500 GW
Regional Comparison

How Mountain Home Afb compares

Full Idaho rankings →

Mountain Home Afb's score of 47.5/100 is on par with the average of 43/100 among major Idaho cities. It outscores 9 of 10 nearby cities.

Mountain Home Afb (this city)
47.5
Boise
33.6
Meridian
42.9
Nampa
41.8
Caldwell
38.5
Idaho avg
43
City Profile

About Mountain Home Afb, ID

Economic Profile
$60,764
Median Income
$1,546/mo
Median Rent
9.5%
Unemployment
Community
23
Median Age
123
People / sq mi
31.7%
College Educated
0.7%
Homeownership
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Frequently asked questions

Is Mountain Home Afb, ID tap water safe to drink?

Mountain Home Afb's water quality earned a grade of D (47.5/100). Significant issues have been found. A water filter is strongly recommended. The city ranks #107 out of 139 cities tested in Idaho.

What contaminants are in Mountain Home Afb's water?

Lead was measured at 0.0 ppb (90th percentile). 4 PFAS compounds were detected. 232 violations are on record.

How is Mountain Home Afb's water quality grade calculated?

The grade is based on four factors: violation history (40%), lead and copper levels (25%), PFAS contamination (25%), and regulatory compliance (10%). The score is also adjusted based on how complete the available data is. See our methodology page for full details.

Do I need a water filter in Mountain Home Afb?

PFAS compounds have been detected. A filter with activated carbon can help reduce exposure.

Where does Mountain Home Afb's water come from?

Mountain Home Afb's water is sourced from Groundwater. The city has 1 water system serving approximately 7,500 residents.

What health violations has Mountain Home Afb's water system had?

Mountain Home Afb has 17 health-based violations on record. The most recent violation was recorded in December 2025. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 3 violations remain unresolved.

Is Mountain Home Afb's groundwater at risk of contamination?

Mountain Home Afb uses groundwater, which can be affected by naturally occurring contaminants like arsenic, radon, and nitrate, as well as agricultural runoff and industrial activity. The system has 232 violations on record that may relate to groundwater quality. Groundwater systems are generally less susceptible to surface contamination but should be monitored for emerging contaminants like PFAS.

Why does Mountain Home Afb have so many PFAS compounds in its water?

4 different PFAS "forever chemical" compounds were detected in Mountain Home Afb's water supply during UCMR 5 testing. PFAS contamination often originates from proximity to military installations (AFFF firefighting foam), airports, industrial manufacturing sites, or wastewater treatment facilities. While detected, current levels are within EPA limits. An activated carbon filter can further reduce exposure.

How does Mountain Home Afb's water compare to other cities?

Mountain Home Afb ranks #107 out of 139 cities in Idaho (better than 23% of state cities) and #13592 out of 15744 cities nationally (14th percentile). The grade of D reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.