Manganese has turned up often in Prince William County wells, mostly from one small area.
1 likely overstated, 1 worth checking, 4 rare out of 6 health checks.
From 13 wells tested in Prince William County since 2003; your own well needs its own test. How to read this
*Manganese: Almost all of these tests come from the US Geological Survey in one small part of the county, so this likely overstates it.
Not charted, because fewer than 10 wells were tested: radon (1).
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 11 people 43,870 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 Prince William County compares with Virginia and the counties around it.
Each result puts Prince William County next to the 7 counties that border it, on the chart's 0 to 50% scale.
This one has turned up often here, mostly from one small area.
Manganese7 of 13 wells over
* Likely overstated, so we don't rank it.
Too few tested to show: Fauquier, Loudoun, Manassas Park city, Manassas city, Stafford.
Almost all of these tests come from the US Geological Survey in one small part of the county, so this likely overstates it.
This one is worth checking in Prince William County.
Nitrate1 of 13 wells over
Too few tested to show: Fauquier, Loudoun, Manassas Park city, Manassas city, Stafford.
These 4 are rare in Prince William County.
Fluoride0 of 13 wells over
Too few tested to show: Fauquier, Loudoun, Manassas Park city, Manassas city, Stafford.
Arsenic0 of 13 wells over
Too few tested to show: Fauquier, Loudoun, Manassas Park city, Manassas city, Stafford.
Uranium0 of 13 wells over
Too few tested to show: Fauquier, Loudoun, Manassas Park city, Manassas city, Stafford.
Lead0 of 13 wells over
Too few tested to show: Fauquier, Loudoun, Manassas Park city, Manassas city, Stafford.
Too few Prince William County wells were tested for this one.
Radon in water1 well tested
Coliform bacteria turned up in 2 of 2 tested Prince William County wells, so test for it every year.
Coliform bacteria2 of 2 wells had it
E. coli0 of 2 wells had it
E. coli means human or animal waste is getting in, so if a test of your Prince William County well finds it, boil drinking water until the well is fixed.
Iron reached staining levels in 8 of 13 tested wells, and it isn't a health risk.
Iron stains8 of 13 wells had it
Too few tested to show: Fauquier, Loudoun, Manassas Park city, Manassas city, Stafford.
Prince William County has 13 tested wells, and the busiest decade for testing was the 2010s.
None of the 13 wells has a test from 2020 or later, so a fresh test of your own well tells you more than any of these.
Most Prince William 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 Prince William County.
- Bacteria
- Nitrate
- Manganese
- Arsenic
What Virginia offers well owners
- Free testingVirginia Cooperative Extension's Virginia Household Water Quality Program runs drinking water clinics in about 70 counties each year at $70 per kit, with financial help available through SERCAP. See the program
- Certified labsVirginia's list of certified labs
- Well recordsWe didn't find an online search.
- New wellsVirginia's Private Well Regulations (12VAC5-630) require newly constructed wells to be tested for coliform bacteria as a condition for use; testing at home purchase is not required by VDH.
Half the wells on record here are shallower than 205 feet.
That comes from 2,743 wells in Virginia's drilling records. Most wells of every kind here are 145 to 280 feet deep. Wells as deep as Prince William 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 66 of the 102 other Virginia 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 Prince William County.
Prince William 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 5 town water systems in Prince William County test for PFAS. 3 of them had at least one test above 4 ng/L, the new EPA limit for PFOA and PFOS. The highest single result was 7.9 ng/L of PFOA. No well in Prince William 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 Prince William County
Is well water in Prince William County safe to drink?
7 of 13 wells tested in Prince William County had manganese over the limit, about 5 in 10. Across Virginia it's about 1 in 10. We don't rank this against other Virginia counties, because most of these tests come from one small area. Almost all of these tests come from the US Geological Survey in one small part of the county, so this likely overstates it. So test your own well for manganese before you count on it.
Can I get my well tested for free in Prince William County?
Virginia Cooperative Extension's Virginia Household Water Quality Program runs drinking water clinics in about 70 counties each year at $70 per kit, with financial help available through SERCAP. If not, use a lab Virginia has certified for drinking water. Ask for bacteria, nitrate, manganese and arsenic, the tests that matter most in Prince William County.
How deep are wells in Prince William County?
Half the wells on record here are shallower than 205 feet. Typical wells on record here are shallower than in 66 of the 102 other Virginia counties with enough drilling records.
How does Prince William County compare with the counties around it?
For manganese, the share of tested wells over the limit: Prince William County, at 54%, had a higher share than all 2 neighboring counties with data. Groundwater doesn't stop at county lines, so Fairfax's 20% is worth knowing about if you live near it.
How often should I test my well in Prince William County?
In Prince William County, 2 of 2 tested wells had coliform bacteria, so the CDC's advice matters here: 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 Prince William County numbers come from
- People on wells: 43,870 in Prince William County, from EPA estimates built on the 2020 Census (Murray et al.).
- Lab tests: 220 well water samples from 13 wells in the Water Quality Portal, run by the USGS and EPA, 2003 to 2015.
- Well depths: 2,743 Virginia drilling records for Prince William County, gathered in the US Groundwater Well Database (Lin and others, 2024).
- Neighboring counties: the 7 counties that share a border with Prince William County, from the Census Bureau's county adjacency file.
- Results marked likely overstated: our own check of who tested the wells, when and where.
- PFAS: EPA tests of 5 town water systems in Prince William County under the Fifth Unregulated Contaminant Monitoring Rule, 2023 to 2025.
- Radon: Prince William County is zone 2 on the EPA Map of Radon Zones.
- State programs and links: Department of Health (VDH), Office of Environmental Health Services, checked November 1, 2026.