Manganese and arsenic are worth checking in Anne Arundel County wells.

2 worth checking, 5 rare out of 7 health checks.

From 68 wells tested in Anne Arundel County since 2000; your own well needs its own test. How to read this

Tested wells over the limit Anne ArundelMaryland

Manganese9%4 of 47 Arsenic6%3 of 47 Nitrate1%1 of 68 Radon0%0 of 20 Lead0%0 of 26 Fluoride0%0 of 47 Uranium0%0 of 21

GermsTest every year, whatever the chart says

Coliform bacteria0%0 of 2 E. coli0%0 of 2

StainsNot a health risk

Iron stains72%34 of 47

Rare: under 5%Worth checking: 5 to 15%Widespread: 15%+

Lab results: Water Quality Portal (USGS and EPA)

Show bacteria and iron

Who drinks from a well here

1 in 3 people 178,479 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)

LowMiddleHigh

Possible here. A home air test is inexpensive.

Radon zones: EPA map

Here's how Anne Arundel County compares with Maryland and the counties around it.

Each result puts Anne Arundel County next to the 8 counties that border it, on the chart's 0 to 50% scale.

These 2 are worth checking in Anne Arundel County.

Manganese4 of 47 wells over

About 1 in 12 wells tested here from 2000 to 2022 were over the EPA health advisory of 0.3 mg/L, against about 2 in 10 across Maryland. Half the results were under 0.059 mg/L, and the top 1 in 10 were 0.23 mg/L or more. That's a bigger share than in 9 of the 17 other Maryland counties with 10 or more tested wells.

Anne Arundel and its neighbors

Baltimore14%

Anne Arundel9%

Kent4%

Calvert0%

Queen Anne's0%

Talbot0%

Too few tested to show: Baltimore city, Howard, Prince George's.

Manganese guide

Arsenic3 of 47 wells over

3 of 47 wells tested here from 2000 to 2022 were over the EPA limit of 10 µg/L, against about 1 in 12 across Maryland. At least half the results were too low for the lab to measure, and the top 1 in 10 were 1.7 µg/L or more. That's a smaller share than in 8 of the 15 other Maryland counties with 10 or more tested wells.

Anne Arundel and its neighbors

Kent30%

Talbot23%

Queen Anne's11%

Anne Arundel6%

Calvert0%

Too few tested to show: Baltimore, Baltimore city, Howard, Prince George's.

Arsenic guide

These 5 are rare in Anne Arundel County.

Nitrate1 of 68 wells over

1 of 68 wells tested here from 2000 to 2022 was over the EPA limit of 10 mg/L, against about 1 in 10 across Maryland. At least half the results were too low for the lab to measure, and the top 1 in 10 were 1.2 mg/L or more. That's a smaller share than in 10 of the 17 other Maryland counties with 10 or more tested wells, leaving out 1 county whose results are likely overstated.

Anne Arundel and its neighbors

Kent55%

Queen Anne's38%

Talbot17%

Baltimore5%

Anne Arundel1%

Calvert0%

* Likely overstated, so we don't rank it.

Too few tested to show: Baltimore city, Howard, Prince George's.

Nitrate guide

Radon in water0 of 20 wells over

None of the 20 wells tested here from 2002 to 2017 were over 4,000 pCi/L, a level the EPA proposed, against about 1 in 10 across Maryland. Half the results were under 177 pCi/L, and the top 1 in 10 were 500 pCi/L or more. Anne Arundel County had none, while 3 of the 10 other Maryland counties with 10 or more tested wells had at least one.

Anne Arundel and its neighbors

Baltimore37%

Howard20%

Anne Arundel0%

Calvert0%

Queen Anne's0%

Talbot0%

Too few tested to show: Baltimore city, Kent, Prince George's.

Radon guide

Lead0 of 26 wells over

None of the 26 wells tested here from 2002 to 2022 were over the EPA action level of 15 µg/L, against under 1 in 100 across Maryland. At least half the results were too low for the lab to measure, and the top 1 in 10 were 3.8 µg/L or more. Anne Arundel County had none, while 1 of the 13 other Maryland counties with 10 or more tested wells had at least one.

Anne Arundel and its neighbors

Baltimore2%

Anne Arundel0%

Queen Anne's0%

Talbot0%

Too few tested to show: Baltimore city, Calvert, Howard, Kent, Prince George's.

Lead guide

Fluoride0 of 47 wells over

None of the 47 wells tested here from 2000 to 2022 were over the EPA limit of 4 mg/L, against under 1 in 100 across Maryland. At least half the results were too low for the lab to measure, and the top 1 in 10 were 0.3 mg/L or more. Anne Arundel County had none, while 1 of the 17 other Maryland counties with 10 or more tested wells had at least one.

Anne Arundel and its neighbors

Anne Arundel0%

Baltimore0%

Calvert0%

Kent0%

Queen Anne's0%

Talbot0%

Too few tested to show: Baltimore city, Howard, Prince George's.

Uranium0 of 21 wells over

None of the 21 wells tested here from 2006 to 2022 were over the EPA limit of 30 µg/L, against none across Maryland. At least half the results were too low for the lab to measure, and the top 1 in 10 were 0.18 µg/L or more. Anne Arundel County had none, and neither did any of the 9 other Maryland counties with 10 or more tested wells.

Anne Arundel and its neighbors

Anne Arundel0%

Queen Anne's0%

Talbot0%

Too few tested to show: Baltimore, Baltimore city, Calvert, Howard, Kent, Prince George's.

Uranium guide

None of the 2 Anne Arundel County wells tested for bacteria had it, but every well needs a yearly test.

Coliform bacteria0 of 2 wells had it

None of the 2 wells tested here from 2012 to 2022 had coliform bacteria, against about 4 in 10 across Maryland.

Bacteria guide

E. coli0 of 2 wells had it

None of the 2 wells tested here from 2012 to 2022 had E. coli, against about 1 in 7 across Maryland.

E. coli means human or animal waste is getting in, so if a test of your Anne Arundel County well finds it, boil drinking water until the well is fixed.

Bacteria guide

Iron reached staining levels in 34 of 47 tested wells, and it isn't a health risk.

Iron stains34 of 47 wells had it

About 7 in 10 wells tested here from 2000 to 2022 had enough iron to stain (0.3 mg/L), against about 4 in 10 across Maryland.

Anne Arundel and its neighbors

Anne Arundel72%

Calvert40%

Talbot25%

Queen Anne's24%

Kent19%

Baltimore18%

Too few tested to show: Baltimore city, Howard, Prince George's.

Iron guide

Most of the 68 wells tested in Anne Arundel County were last tested before 2010.

58 wells had a test in the 2000s, 13 in the 2010s and 1 since 2020.

An old result shows the water as it was then, so treat these 68 wells as a starting point and test your own.

Most Anne Arundel 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 Anne Arundel 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 110 feet.

That comes from 54,621 household wells in Maryland's drilling records. Most wells of every kind here are 75 to 190 feet deep. Wells as deep as Anne Arundel 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 21 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 Anne Arundel County.

Anne Arundel 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 9 town water systems in Anne Arundel County test for PFAS. None found any. No well in Anne Arundel 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

Next door to Anne Arundel County

Baltimore Calvert Queen Anne's

Elsewhere in Maryland

Carroll Harford Frederick St. Mary's Montgomery

All of Maryland

Questions people ask about well water in Anne Arundel County

Is well water in Anne Arundel County safe to drink?

4 of 47 wells tested in Anne Arundel County had manganese over the limit, about 1 in 12. Across Maryland it's about 2 in 10. That's a bigger 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 Anne Arundel 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 Anne Arundel County.

How deep are wells in Anne Arundel County?

Half the household wells here are shallower than 110 feet. Typical household wells here are shallower than in 21 of the 23 other Maryland counties with enough drilling records.

How does Anne Arundel County compare with the counties around it?

For manganese, the share of tested wells over the limit: 1 of the 5 neighboring counties with data had a higher share than Anne Arundel County, at 9%. Baltimore had the most, at 14%. Groundwater doesn't stop at county lines, so Baltimore's 14% is worth knowing about if you live near it.

How often should I test my well in Anne Arundel County?

None of the 2 wells tested for bacteria in Anne Arundel 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.

By the Tested Water teamData from the USGS, EPA and Maryland Department of the EnvironmentUpdated November 8, 2026

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Where the Anne Arundel County numbers come from

People on wells: 178,479 in Anne Arundel County, from EPA estimates built on the 2020 Census (Murray et al.).
Lab tests: 355 well water samples from 68 wells in the Water Quality Portal, run by the USGS and EPA, 2000 to 2022.
Well depths: 54,621 Maryland drilling records for Anne Arundel County, gathered in the US Groundwater Well Database (Lin and others, 2024).
Neighboring counties: the 8 counties that share a border with Anne Arundel County, from the Census Bureau's county adjacency file.
PFAS: EPA tests of 9 town water systems in Anne Arundel County under the Fifth Unregulated Contaminant Monitoring Rule, 2023 to 2025.
Radon: Anne Arundel County is zone 2 on the EPA Map of Radon Zones.
State programs and links: Maryland Department of the Environment, checked November 1, 2026.

Download this county's data (CSV)How we read these numbers Report an error