Nitrate is widespread in Cumberland County wells.
1 widespread, 1 worth checking, 5 rare out of 7 health checks.
From 92 wells tested in Cumberland 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 58,711 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)
Possible here. A home air test is inexpensive.
Radon zones: EPA map
Here's how Cumberland County compares with New Jersey and the counties around it.
Each result puts Cumberland County next to the 5 counties that border it, on the chart's 0 to 50% scale.
This one is widespread in Cumberland County wells.
Nitrate12 of 72 wells over
Too few tested to show: Cape May.
This one is worth checking in Cumberland County.
Manganese5 of 73 wells over
These 5 are rare in Cumberland County.
Lead1 of 27 wells over
Too few tested to show: Cape May.
Arsenic1 of 68 wells over
Fluoride1 of 71 wells over
Radon in water0 of 27 wells over
Too few tested to show: Cape May, Salem.
Uranium0 of 15 wells over
Too few tested to show: Cape May, Kent, DE, Salem.
None of the 6 Cumberland County wells tested for bacteria had it, but every well needs a yearly test.
Coliform bacteria0 of 6 wells had it
E. coli0 of 6 wells had it
E. coli means human or animal waste is getting in, so if a test of your Cumberland County well finds it, boil drinking water until the well is fixed.
Iron reached staining levels in 33 of 75 tested wells, and it isn't a health risk.
Iron stains33 of 75 wells had it
About 4 in 10 of the 92 wells tested in Cumberland County have a test from 2020 or later.
With 39 wells tested since 2020, age matters less here than who did the testing and why.
Most Cumberland 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 Cumberland County.
- Bacteria
- Nitrate
- Manganese
- Arsenic
What New Jersey offers well owners
- Free testingWe didn't find a free program for all of New Jersey. New Jersey's private well page
- Certified labsNew Jersey's list of certified labs
- Well recordsNew Jersey's well record search
- New wellsUnder the Private Well Testing Act (N.J.S.A. 58:12A-26 et seq.), every sale of property with a private potable well requires a water test before closing of title, and landlords must test at least every five years.
Half the wells on record here are shallower than 100 feet.
That comes from 2,320 wells in New Jersey's drilling records. Most wells of every kind here are 80 to 120 feet deep. Wells as deep as Cumberland 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 12 of the 19 other New Jersey counties with enough drilling records.
Look up your own well's depth in New Jersey's well record search, or see how to find it.
Well depths: US Groundwater Well Database
Here's what we know about radon and PFAS in Cumberland County.
Cumberland 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 4 town water systems in Cumberland 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 11 ng/L of PFOS. Only 9 wells in Cumberland County have 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 Cumberland County
Is well water in Cumberland County safe to drink?
12 of 72 wells tested in Cumberland County had nitrate over the limit, about 2 in 10. Across New Jersey it's about 1 in 13. That's a bigger share than in 14 of the 15 other New Jersey counties with 10 or more tested wells. So test your own well for nitrate before you count on it.
Where can I get my well tested in Cumberland County?
Use a lab New Jersey has certified for drinking water. New Jersey's list is linked above, in the box about testing. Ask for bacteria, nitrate, manganese and arsenic, the tests that matter most in Cumberland County.
How deep are wells in Cumberland County?
Half the wells on record here are shallower than 100 feet. Typical wells on record here are shallower than in 12 of the 19 other New Jersey counties with enough drilling records.
How does Cumberland County compare with the counties around it?
For nitrate, the share of tested wells over the limit: 1 of the 4 neighboring counties with data had a higher share than Cumberland County, at 17%. Salem had the most, at 44%. Groundwater doesn't stop at county lines, so Salem's 44% is worth knowing about if you live near it.
How often should I test my well in Cumberland County?
None of the 6 wells tested for bacteria in Cumberland 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.
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 Cumberland County numbers come from
- People on wells: 58,711 in Cumberland County, from EPA estimates built on the 2020 Census (Murray et al.).
- Lab tests: 862 well water samples from 92 wells in the Water Quality Portal, run by the USGS and EPA, 2000 to 2023.
- Well depths: 2,320 New Jersey drilling records for Cumberland County, gathered in the US Groundwater Well Database (Lin and others, 2024).
- Neighboring counties: the 5 counties that share a border with Cumberland County, from the Census Bureau's county adjacency file.
- PFAS: EPA tests of 4 town water systems in Cumberland County under the Fifth Unregulated Contaminant Monitoring Rule, 2023 to 2025.
- Radon: Cumberland County is zone 2 on the EPA Map of Radon Zones.
- State programs and links: Department of Environmental Protection, checked November 1, 2026.