Nitrate is widespread in Wicomico County wells.
1 widespread, 1 worth checking, 1 rare out of 3 health checks.
From 19 wells tested in Wicomico County since 2000; your own well needs its own test. How to read this
Not charted, because fewer than 10 wells were tested: arsenic (9), uranium (3), radon (3), lead (7).
Rare: under 5%Worth checking: 5 to 15%Widespread: 15%+
Lab results: Water Quality Portal (USGS and EPA)
Who drinks from a well here
5 in 10 people 55,610 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)
Less likely, but the EPA still says test your air.
Radon zones: EPA map
Here's how Wicomico County compares with Maryland and the counties around it.
Each result puts Wicomico County next to the 4 counties that border it, on the chart's 0 to 50% scale.
This one is widespread in Wicomico County wells.
Nitrate3 of 19 wells over
Too few tested to show: Somerset.
This one is worth checking in Wicomico County.
Manganese2 of 16 wells over
Too few tested to show: Somerset.
This one is rare in Wicomico County.
Fluoride0 of 13 wells over
Too few tested to show: Somerset.
Too few Wicomico County wells were tested for these 4.
Arsenic9 wells tested
Uranium3 wells tested
Radon in water3 wells tested
Lead7 wells tested
None of the 1 Wicomico County wells tested for bacteria had it, but every well needs a yearly test.
Coliform bacteria0 of 1 wells had it
E. coli0 of 1 wells had it
E. coli means human or animal waste is getting in, so if a test of your Wicomico County well finds it, boil drinking water until the well is fixed.
Iron reached staining levels in 6 of 18 tested wells, and it isn't a health risk.
Iron stains6 of 18 wells had it
Too few tested to show: Somerset.
Most of the 19 wells tested in Wicomico County were last tested before 2010.
An old result shows the water as it was then, so treat these 19 wells as a starting point and test your own.
Most Wicomico 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 Wicomico 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 80 feet.
That comes from 24,368 household wells in Maryland's drilling records. Most wells of every kind here are 60 to 103 feet deep. Wells as deep as Wicomico 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 shallowest 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 Wicomico County.
Wicomico County is in the EPA's lowest radon zone, so radon from well water is unlikely to be a problem. Radon guide
Between 2023 and 2025 the EPA had 3 town water systems in Wicomico 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 20 ng/L of PFOS. No well in Wicomico 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 Wicomico County
Is well water in Wicomico County safe to drink?
3 of 19 wells tested in Wicomico County had nitrate over the limit, about 2 in 10. Across Maryland it's about 1 in 10. That's a bigger share than in 14 of the 17 other Maryland counties with 10 or more tested wells, leaving out 1 county whose results are likely overstated. So test your own well for nitrate before you count on it.
Where can I get my well tested in Wicomico 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 Wicomico County.
How deep are wells in Wicomico County?
Half the household wells here are shallower than 80 feet. That's the shallowest typical depth for household wells among the 24 Maryland counties with enough drilling records.
How does Wicomico County compare with the counties around it?
For nitrate, the share of tested wells over the limit: 1 of the 3 neighboring counties with data had a higher share than Wicomico County, at 16%. Sussex, DE had the most, at 26%. Groundwater doesn't stop at county lines, so Sussex, DE's 26% is worth knowing about if you live near it.
How often should I test my well in Wicomico County?
None of the 1 wells tested for bacteria in Wicomico County had it, but the CDC still says to 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 Wicomico County numbers come from
- People on wells: 55,610 in Wicomico County, from EPA estimates built on the 2020 Census (Murray et al.).
- Lab tests: 117 well water samples from 19 wells in the Water Quality Portal, run by the USGS and EPA, 2000 to 2023.
- Well depths: 24,368 Maryland drilling records for Wicomico County, gathered in the US Groundwater Well Database (Lin and others, 2024).
- Neighboring counties: the 4 counties that share a border with Wicomico County, from the Census Bureau's county adjacency file.
- PFAS: EPA tests of 3 town water systems in Wicomico County under the Fifth Unregulated Contaminant Monitoring Rule, 2023 to 2025.
- Radon: Wicomico County is zone 3 on the EPA Map of Radon Zones.
- State programs and links: Maryland Department of the Environment, checked November 1, 2026.