Only 1 health check had enough tested wells in Harford County, and it came back rare.
The only health check here came back rare.
From 56 wells tested in Harford County since 2000; 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 85,317 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)
Likely here. Test your home's air first.
Radon zones: EPA map
Here's how Harford County compares with Maryland and the counties around it.
Each result puts Harford County next to the 5 counties that border it, on the chart's 0 to 50% scale.
The only health check in Harford County is rare.
Nitrate0 of 49 wells over
* Likely overstated, so we don't rank it.
Too few Harford County wells were tested for these 6.
Arsenic7 wells tested
Uranium4 wells tested
Radon in water8 wells tested
Manganese7 wells tested
Lead7 wells tested
Fluoride4 wells tested
Every well needs a bacteria test every year.
No bacteria tests from Harford County wells are in the public data. Test every year anyway.
Iron reached staining levels in 6 of 52 tested wells, and it isn't a health risk.
Iron stains6 of 52 wells had it
Too few tested to show: York, PA.
Most of the 56 wells tested in Harford County were last tested before 2010.
An old result shows the water as it was then, so treat these 56 wells as a starting point and test your own.
Most Harford 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 Harford County.
- Bacteria
- Nitrate
- 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 160 feet.
That comes from 26,604 household wells in Maryland's drilling records. Most wells of every kind here are 100 to 275 feet deep. Wells as deep as Harford 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 household wells here are shallower than in 13 of the 23 other 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 Harford County.
Harford 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 5 town water systems in Harford County test for PFAS. 2 of them had at least one test above 4 ng/L, the new EPA limit for PFOA and PFOS. The highest single result was 9.3 ng/L of PFOA. No well in Harford 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 Harford County
Is well water in Harford County safe to drink?
Most tested wells in Harford County came in under the limits. Of 1 health check with enough tests, nitrate came closest, at 0 of 49 wells over. Every well is different, so test yours for bacteria, nitrate and arsenic.
Where can I get my well tested in Harford 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 and arsenic, the tests that matter most in Harford County.
How deep are wells in Harford County?
Half the household wells here are shallower than 160 feet. Typical household wells here are shallower than in 13 of the 23 other Maryland counties with enough drilling records.
How does Harford County compare with the counties around it?
For nitrate, the share of tested wells over the limit: 4 of the 5 neighboring counties with data had a higher share than Harford County, at 0%. Kent had the most, at 55%. Groundwater doesn't stop at county lines, so Kent's 55% is worth knowing about if you live near it.
How often should I test my well in Harford County?
Harford 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.
If you buy something through our links, we may earn a commission. We'd recommend the same thing either way, and we'll tell you when a free option exists. How we make money
Where the Harford County numbers come from
- People on wells: 85,317 in Harford County, from EPA estimates built on the 2020 Census (Murray et al.).
- Lab tests: 145 well water samples from 56 wells in the Water Quality Portal, run by the USGS and EPA, 2000 to 2020.
- Well depths: 26,604 Maryland drilling records for Harford County, gathered in the US Groundwater Well Database (Lin and others, 2024).
- Neighboring counties: the 5 counties that share a border with Harford County, from the Census Bureau's county adjacency file.
- PFAS: EPA tests of 5 town water systems in Harford County under the Fifth Unregulated Contaminant Monitoring Rule, 2023 to 2025.
- Radon: Harford County is zone 1 on the EPA Map of Radon Zones.
- State programs and links: Maryland Department of the Environment, checked November 1, 2026.