Manganese is worth checking in Morris County wells.
1 worth checking, 5 rare out of 6 health checks.
From 32 wells tested in Morris County since 2000; your own well needs its own test. How to read this
Not charted, because fewer than 10 wells were tested: radon (9).
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 6 people 87,541 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 Morris County compares with New Jersey and the counties around it.
Each result puts Morris County next to the 7 counties that border it, on the chart's 0 to 50% scale.
This one is worth checking in Morris County.
Manganese4 of 32 wells over
Too few tested to show: Essex, Passaic, Union.
These 5 are rare in Morris County.
Nitrate0 of 31 wells over
Too few tested to show: Essex, Passaic, Union.
Uranium0 of 10 wells over
Too few tested to show: Essex, Passaic, Somerset, Union, Warren.
Arsenic0 of 26 wells over
Too few tested to show: Essex, Passaic, Union.
Lead0 of 11 wells over
Too few tested to show: Essex, Passaic, Somerset, Union.
Too few Morris County wells were tested for this one.
Radon in water9 wells tested
Coliform bacteria turned up in 4 of 9 tested Morris County wells, so test for it every year.
Coliform bacteria4 of 9 wells had it
E. coli1 of 9 wells had it
E. coli means human or animal waste is getting in, so if a test of your Morris County well finds it, boil drinking water until the well is fixed.
Iron reached staining levels in 2 of 32 tested wells, and it isn't a health risk.
Iron stains2 of 32 wells had it
Too few tested to show: Essex, Passaic, Union.
Most of the 32 wells tested in Morris County were last tested before 2010.
An old result shows the water as it was then, so treat these 32 wells as a starting point and test your own.
Most Morris 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 Morris 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 250 feet.
That comes from 604 wells in New Jersey's drilling records. Most wells of every kind here are 150 to 300 feet deep. Wells as deep as Morris 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 deepest typical depth for wells on record among the 20 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 Morris County.
Morris 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 36 town water systems in Morris County test for PFAS. 27 of them had at least one test above 4 ng/L, the new EPA limit for PFOA and PFOS. The highest single result was 14 ng/L of PFOA. Only 9 wells in Morris 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 Morris County
Is well water in Morris County safe to drink?
4 of 32 wells tested in Morris County had manganese over the limit, about 1 in 8. Across New Jersey it's about 1 in 8. That's a bigger share than in 8 of the 16 other New Jersey 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 Morris 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 Morris County.
How deep are wells in Morris County?
Half the wells on record here are shallower than 250 feet. That's the deepest typical depth for wells on record among the 20 New Jersey counties with enough drilling records.
How does Morris County compare with the counties around it?
For manganese, the share of tested wells over the limit: 1 of the 4 neighboring counties with data had a higher share than Morris County, at 12%. Somerset had the most, at 20%. Groundwater doesn't stop at county lines, so Somerset's 20% is worth knowing about if you live near it.
How often should I test my well in Morris County?
In Morris County, 4 of 9 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.
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Where the Morris County numbers come from
- People on wells: 87,541 in Morris County, from EPA estimates built on the 2020 Census (Murray et al.).
- Lab tests: 470 well water samples from 32 wells in the Water Quality Portal, run by the USGS and EPA, 2000 to 2022.
- Well depths: 604 New Jersey drilling records for Morris County, gathered in the US Groundwater Well Database (Lin and others, 2024).
- Neighboring counties: the 7 counties that share a border with Morris County, from the Census Bureau's county adjacency file.
- PFAS: EPA tests of 36 town water systems in Morris County under the Fifth Unregulated Contaminant Monitoring Rule, 2023 to 2025.
- Radon: Morris County is zone 1 on the EPA Map of Radon Zones.
- State programs and links: Department of Environmental Protection, checked November 1, 2026.