Manganese is worth checking in Charles County wells.
1 worth checking, 6 rare out of 7 health checks.
From 23 wells tested in Charles 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 3 people 57,568 people
Nobody else tests these wells. Only you do.
People on wells: EPA researchers' 2020 estimate
How deep wells go here
Deep wells: fewer surface germs, more minerals from the rock.
Well depths: US Groundwater Well Database
Radon risk (a gas from rock)
Possible here. A home air test is inexpensive.
Radon zones: EPA map
Here's how Charles County compares with Maryland and the counties around it.
Each result puts Charles County next to the 8 counties that border it, on the chart's 0 to 50% scale.
This one is worth checking in Charles County.
Manganese1 of 19 wells over
* Likely overstated, so we don't rank it.
Too few tested to show: King George, VA, Prince George's, Stafford, VA, Westmoreland, VA.
These 6 are rare in Charles County.
Radon in water0 of 13 wells over
Too few tested to show: Fairfax, VA, King George, VA, Prince George's, Prince William, VA, St. Mary's, Stafford, VA, Westmoreland, VA.
Nitrate0 of 18 wells over
Too few tested to show: King George, VA, Prince George's, Stafford, VA, Westmoreland, VA.
Arsenic0 of 18 wells over
Too few tested to show: King George, VA, Prince George's, Stafford, VA, Westmoreland, VA.
Lead0 of 12 wells over
Too few tested to show: Calvert, King George, VA, Prince George's, Stafford, VA, Westmoreland, VA.
Fluoride0 of 19 wells over
Too few tested to show: King George, VA, Prince George's, Stafford, VA, Westmoreland, VA.
Uranium0 of 10 wells over
Too few tested to show: Calvert, King George, VA, Prince George's, Stafford, VA, Westmoreland, VA.
Every well needs a bacteria test every year.
No bacteria tests from Charles County wells are in the public data. Test every year anyway.
Iron reached staining levels in 12 of 19 tested wells, and it isn't a health risk.
Iron stains12 of 19 wells had it
Too few tested to show: King George, VA, Prince George's, Stafford, VA, Westmoreland, VA.
Most of the 23 wells tested in Charles County were last tested before 2010.
An old result shows the water as it was then, so treat these 23 wells as a starting point and test your own.
Most Charles 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 4 things to check in Charles County.
- Bacteria
- Nitrate
- Manganese
- Arsenic
What Maryland offers well owners
- Free testingWe didn't find a free program for all of Maryland. Maryland's private well page
- Certified labsMaryland's list of certified labs
- Well recordsWe didn't find an online search.
- New wellsSince October 1, 2024, Md. Code, Real Property 10-713 requires a contract for sale of property with a private well to make well water quality testing a condition of sale, with both parties certifying they reviewed the results.
Half the household wells here are shallower than 440 feet.
That comes from 16,881 household wells in Maryland's drilling records. Most wells of every kind here are 365 to 495 feet deep. Wells as deep as Charles 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. That's the deepest typical depth for household wells among the 24 Maryland counties with enough drilling records.
How to find your own well's depth
Well depths: US Groundwater Well Database
Here's what we know about radon and PFAS in Charles County.
Charles County is in the EPA's middle radon zone. An indoor air test is cheap and tells you whether to look at your water. Radon guide
Between 2023 and 2025 the EPA had 6 town water systems in Charles County test for PFAS. 1 found some PFAS, all below the new limits. No well in Charles 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 Charles County
Is well water in Charles County safe to drink?
1 of 19 wells tested in Charles County had manganese over the limit, about 1 in 19. Across Maryland it's about 2 in 10. That's a smaller share than in 9 of the 17 other Maryland counties with 10 or more tested wells. So test your own well for manganese before you count on it.
Where can I get my well tested in Charles County?
Use a lab Maryland has certified for drinking water. Maryland's list is linked above, in the box about testing. Ask for bacteria, nitrate, manganese and arsenic, the tests that matter most in Charles County.
How deep are wells in Charles County?
Half the household wells here are shallower than 440 feet. That's the deepest typical depth for household wells among the 24 Maryland counties with enough drilling records.
How does Charles County compare with the counties around it?
For manganese, the share of tested wells over the limit: 2 of the 4 neighboring counties with data had a higher share than Charles County, at 5%. Prince William, VA had the most, at 54%. Groundwater doesn't stop at county lines, so Prince William, VA's 54% is worth knowing about if you live near it.
How often should I test my well in Charles County?
Charles 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 Charles County numbers come from
- People on wells: 57,568 in Charles County, from EPA estimates built on the 2020 Census (Murray et al.).
- Lab tests: 144 well water samples from 23 wells in the Water Quality Portal, run by the USGS and EPA, 2001 to 2022.
- Well depths: 16,881 Maryland drilling records for Charles County, gathered in the US Groundwater Well Database (Lin and others, 2024).
- Neighboring counties: the 8 counties that share a border with Charles County, from the Census Bureau's county adjacency file.
- PFAS: EPA tests of 6 town water systems in Charles County under the Fifth Unregulated Contaminant Monitoring Rule, 2023 to 2025.
- Radon: Charles County is zone 2 on the EPA Map of Radon Zones.
- State programs and links: Maryland Department of the Environment, checked November 1, 2026.