Well water in Morris County, New Jersey
In Morris County, 20% of 13,108 private wells tested between 2002 and 2024 had total coliform above the New Jersey limit (any detection), according to NJDEP.
13,112 private wells tested 2002 to 2024 in state summaries; 520 individual samples from 320 wells, 1983 to 2025. Data refreshed September 9, 2026.
What homeowner tests found
NJDEP Private Well Testing Act summaries: private wells tested and reported to the state, 2002 to 2024. Shares are against the level the state applies to each contaminant, named in the last column; several are stricter than EPA.
| Contaminant | Wells tested | Above state level | Median | 95th pct | Highest | State level | |
|---|---|---|---|---|---|---|---|
| Iron | 13,112 | 25% | 300 ug/L | ||||
| Total coliform | 13,108 | 20% | |||||
| Manganese | 13,112 | 19% | 50 ug/L | ||||
| PFOA | 1,851 | 14% | 14 ng/L | ||||
| PFOS | 1,851 | 8% | 13 ng/L | ||||
| Gross alpha | 4,291 | 4% | 15 pCi/L | ||||
| E. coli Fecal coliform or | 13,065 | 2% | |||||
| Nitrate | 13,110 | 2% | 10 mg/L | ||||
| Arsenic | 13,097 | 2% | 5 ug/L | ||||
| Uranium | 3,810 | <1% | 30 ug/L | ||||
| PFNA | 1,851 | <1% | 13 ng/L |
What individual samples found
Each row summarizes every public sample for that contaminant inside Morris County. Above limit means above the EPA maximum contaminant level; where EPA has no enforceable limit, the row shows a health guideline or nuisance level instead.
| Contaminant | Samples | Detected | Above limit | Median | Highest | Limit | |
|---|---|---|---|---|---|---|---|
| PFOA 2022 to 2025 | 18 | 67% | 61% | 7.5 | 58 | 4 ng/L EPA limit | |
| PFOS 2022 to 2025 | 18 | 56% | 44% | 2.65 | 26 | 4 ng/L EPA limit | |
| Uranium 1997 to 2014 | 31 | 58% | 3% | 0.055 | 429 | 30 ug/L EPA limit | |
| Arsenic 1983 to 2025 | 520 | 41% | 1% | 0 | 17 | 10 ug/L EPA limit | |
| Radium (226 + 228) 1999 to 2014 | 28 | 75% | 0% | 0 | 1.71 | 5 pCi/L EPA limit | |
| Lead 1985 to 1994 | 13 | 8% | 0% | 0 | 10 | 15 ug/L EPA limit | |
| Fluoride 1985 to 2016 | 12 | 67% | 0% | 0.1 | 0.5 | 4 mg/L EPA limit | |
| Nitrate 1985 to 2011 | 10 | 60% | 0% | 0.12 | 2.8 | 10 mg/L EPA limit | |
| Radon 1987 to 2014 | 34 | 100% | no limit | 1,555 | 31,800 | 2,000 pCi/L health guideline | |
| Manganese 1985 to 2019 | 10 | 90% | no limit | 280 | 2,000 | 300 ug/L health guideline | |
| Iron 1984 to 2022 | 10 | 90% | no limit | 35 | 660 | 300 ug/L nuisance level |
Sampled fewer than 10 times, too few to summarize: Copper (7), Sodium (8), Chloride (4).
Get the free Morris County well report
One email with the numbers above, what they mean for a home in Morris County, exactly which tests to order, and what treatment fits the local profile. No spam, unsubscribe in one click.
What this means
Among homeowners in Morris County who sent a sample to the state lab, the health-based limits most often exceeded were total coliform (20% of 13,108 wells), PFOA (14% of 1,851 wells), and PFOS (8% of 1,851 wells). These are ordinary wells tested by their owners, so the shares are the best available picture of a typical well here, with one caveat: people test more often when they suspect a problem.
Iron and manganese exceed the state's advisory level in a sizable share of wells; these are mostly a taste, staining or diet issue rather than a toxicity one.
What to test for in Morris County
- Volatile organic compounds (VOCs)12 hazardous waste sites on record locally.
- Metals panel12 hazardous waste sites on record locally.
- Iron25% of 13,112 local wells tested were above the New Jersey nuisance level.
- Total coliform20% of 13,108 local wells tested were above the New Jersey limit (any detection).
- Manganese19% of 13,112 local wells tested were above the New Jersey nuisance level.
- Gross alpha4% of 4,291 local wells tested were above the New Jersey limit.
- E. coli2% of 13,065 local wells tested were above the New Jersey limit (any detection).
- Nitrate2% of 13,110 local wells tested were above the New Jersey limit.
- PFNA<1% of 1,851 local wells tested were above the New Jersey limit.
- RadonMedian local reading is 1,555 pCi/L.
Contamination sources on record in Morris County
NJDEP records 12 hazardous waste sites in Morris County, among 3,012 regulated sites in total. Groundwater does not follow property lines, so a well within a few hundred feet of one of these is worth testing for what that site could release.
- 12
- hazardous waste sitesSolvents, degreasers and metals from industrial sites can travel far in fractured bedrock.
- 2,406
- registered underground storage tank sitesRegistered tanks are regulated and inspected; they matter most when they are old or near a shallow well.
- 21
- lined landfills and transfer facilities
- 573
- other remediation projects
Treatment that fits the local profile
- Total coliform
- Inspect and repair the well cap and casing, then shock chlorinate and retest; UV disinfection whole-house; Chlorination system
- PFOA
- Granular activated carbon whole-house; Point-of-use reverse osmosis; Anion exchange
- PFOS
- Granular activated carbon whole-house; Point-of-use reverse osmosis; Anion exchange
- Iron
- Oxidizing filter whole-house; Water softener (low levels); Aeration plus filtration
- Manganese
- Oxidizing filter (greensand, birm) whole-house; Water softener (low levels); Point-of-use reverse osmosis
- Uranium
- Point-of-use reverse osmosis; Anion exchange; Whole-house anion exchange
Get your Morris County water tested at home
A licensed local water treatment company tests your tap water in your home, walks you through the numbers, and quotes treatment only if something needs fixing. Free, about 30 minutes, no obligation. Tell us what you need and we match you with a company that serves Morris County.
Common questions
Is there arsenic in well water in Morris County?
Arsenic was detected in 41% of 520 public well samples in Morris County, and 1% were above the EPA limit of 10 ug/L. Arsenic has no taste or smell; a lab test is the only way to know your level.
How high is radon in well water in Morris County?
The median radon level across 34 public samples in Morris County was 1,555 pCi/L, with a high of 31,800 pCi/L. New Hampshire recommends treatment above 2,000 pCi/L.
How often should I test a private well in Morris County?
Test for bacteria and nitrate every year. Test once for arsenic, uranium, radon, fluoride, manganese and PFAS, then again every three to five years or after any change in taste, color, or plumbing.
Towns in Morris County
- Boonton township24% pfoa
- Chester borough13% total coliform
- Chester township19% total coliform
- Denville township19% total coliform
- Harding township26% total coliform
- Jefferson township23% total coliform
- Kinnelon borough20% pfoa
- Lincoln Park borough19% total coliform
- Long Hill township21% total coliform
- Mendham borough16% arsenic
- Mendham township22% total coliform
- Mine Hill township30% total coliform
- Montville township49% pfoa
- Morris township15% total coliform
- Mount Arlington borough24% total coliform
- Mount Olive township21% total coliform
- Parsippany-Troy Hills township27% total coliform
- Randolph township19% total coliform
- Riverdale borough20% total coliform
- Rockaway township33% pfoa
- Roxbury township18% total coliform
- Washington township18% total coliform
17 towns have fewer than 30 public samples and are included in the Morris County totals above rather than shown separately: Boonton, Butler borough, Chatham borough, Chatham township, Dover, East Hanover township, Florham Park borough, Hanover township, Madison borough, Morris Plains borough, Morristown, Mountain Lakes borough, Netcong borough, Pequannock township, Rockaway borough, Victory Gardens borough, Wharton borough.
Sources
- USGS Water Quality Portal: 723 samples in Morris County. Data from the Water Quality Portal, a service of USGS, EPA and USDA; groundwater samples collected by USGS and cooperators. Retrieved September 3, 2026.
- NJDEP Private Well Testing Act summaries: summaries for 11 contaminants in Morris County, up to 13,112 wells each. Share of private wells exceeding each standard in tests required at sale or lease under the New Jersey Private Well Testing Act, September 2002 to December 2024, published by NJDEP. Tests are untreated water at the time of sale or lease, so every well is counted once per transaction. Municipalities with fewer than ten wells are suppressed. Standards are New Jersey's: arsenic 5 ug/L, PFOA 14 ng/L, PFOS 13 ng/L, PFNA 13 ng/L, manganese and iron secondary standards. Uranium and PFAS were added to the required panel in 2021 and 2020, so their well counts are smaller. Retrieved September 9, 2026.
- NJDEP regulated sites: 3,012 regulated sites located in Morris County. Known Contaminated Sites, regulated underground storage tank facilities and solid waste landfills from the New Jersey Department of Environmental Protection (NJ-GeoWeb). Retrieved September 9, 2026.
Non-detects count as samples and are treated as zero when computing medians. Exactly at the limit counts as not above it. A sample belongs to the town containing the well's reported coordinates.