Arsenic is widespread in Montgomery County wells.
1 widespread, 4 rare out of 5 health checks.
From 37 wells tested in Montgomery County since 2001; your own well needs its own test. How to read this
Rare: under 5%Worth checking: 5 to 15%Widespread: 15%+
Lab results: Water Quality Portal (USGS and EPA)
Who drinks from a well here
1 in 2 people 15,937 people
Nobody else tests these wells. Only you do.
People on wells: EPA researchers' 2020 estimate
How deep wells go here
Middle depth: some shelter from the surface, not complete.
Well depths: US Groundwater Well Database
Radon risk (a gas from rock)
Likely here. Test your home's air first.
Radon zones: EPA map
Here's how Montgomery County compares with Indiana and the counties around it.
Each result puts Montgomery County next to the 7 counties that border it, on the chart's 0 to 50% scale.
This one is widespread in Montgomery County wells.
Arsenic7 of 37 wells over
These 4 are rare in Montgomery County.
Manganese0 of 16 wells over
Nitrate0 of 16 wells over
Uranium0 of 16 wells over
Lead0 of 16 wells over
Every well needs a bacteria test every year.
No bacteria tests from Montgomery County wells are in the public data. Test every year anyway.
Most of the 37 wells tested in Montgomery County were last tested before 2010.
An old result shows the water as it was then, so treat these 37 wells as a starting point and test your own.
Most Montgomery County wells in these records were tested for research or because someone suspected a problem, which can push the shares above what a typical home well would show (how we read the numbers).
One mail-in lab test covers the 3 things to check in Montgomery County.
- Bacteria
- Nitrate
- Arsenic
What Indiana offers well owners
- Free testingIDEM's Groundwater Monitoring Network offers free well water testing to eligible private residential wells (2026 announcement at events.in.gov/event/gwmn-welltesting-2026). See the program
- Certified labsIndiana's list of certified labs
- Well recordsIndiana's well record search
Half the wells on record here are shallower than 82 feet.
That comes from 4,675 wells in Indiana's drilling records. Most wells of every kind here are 61 to 110 feet deep. Wells as deep as Montgomery County's are usually better protected from fertilizer and bacteria at the surface, but they can pick up more of what's in the rock, like arsenic and uranium. Typical wells on record here are shallower than in 59 of the 87 other Indiana counties with enough drilling records.
Look up your own well's depth in Indiana's well record search, or see how to find it.
Well depths: US Groundwater Well Database
Here's what we know about radon and PFAS in Montgomery County.
Montgomery County is in the EPA's highest radon zone. Radon from well water adds to the radon in your indoor air, so test your air first, and your water too if the air is high. Radon guide
Between 2023 and 2025 the EPA had 1 town water system in Montgomery County test for PFAS. 1 found some PFAS, all below the new limits. No well in Montgomery County has public PFAS results, so the town systems are the best clue to what's in the groundwater nearby. PFAS guide
Radon zones: EPA Map of Radon Zones. PFAS: EPA tests of town water systems, 2023 to 2025
Questions people ask about well water in Montgomery County
Is well water in Montgomery County safe to drink?
7 of 37 wells tested in Montgomery County had arsenic over the limit, about 2 in 10. Across Indiana it's about 2 in 10. That's a bigger share than in 3 of the 4 other Indiana counties with 10 or more tested wells. So test your own well for arsenic before you count on it.
Can I get my well tested for free in Montgomery County?
IDEM's Groundwater Monitoring Network offers free well water testing to eligible private residential wells (2026 announcement at events.in.gov/event/gwmn-welltesting-2026). If not, use a lab Indiana has certified for drinking water. Ask for bacteria, nitrate and arsenic, the tests that matter most in Montgomery County.
How deep are wells in Montgomery County?
Half the wells on record here are shallower than 82 feet. Typical wells on record here are shallower than in 59 of the 87 other Indiana counties with enough drilling records.
How often should I test my well in Montgomery County?
Montgomery County has no public bacteria results for wells, so follow the CDC's advice: test for bacteria and nitrate every year, and right away after a flood, a repair, or any change in taste or smell.
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Where the Montgomery County numbers come from
- People on wells: 15,937 in Montgomery County, from EPA estimates built on the 2020 Census (Murray et al.).
- Lab tests: 105 well water samples from 37 wells in the Water Quality Portal, run by the USGS and EPA, 2001 to 2002.
- Well depths: 13 Indiana drilling records for Montgomery County, gathered in the US Groundwater Well Database (Lin and others, 2024).
- Neighboring counties: the 7 counties that share a border with Montgomery County, from the Census Bureau's county adjacency file.
- PFAS: EPA tests of 1 town water systems in Montgomery County under the Fifth Unregulated Contaminant Monitoring Rule, 2023 to 2025.
- Radon: Montgomery County is zone 1 on the EPA Map of Radon Zones.
- State programs and links: Indiana Department of Health, checked November 1, 2026.