Well water in Essex County, New Jersey
In Essex County, 11% of 231 private wells tested between 2002 and 2024 had arsenic above the New Jersey limit (5 ug/L), according to NJDEP.
231 private wells tested 2002 to 2024 in state summaries; 41 individual samples from 20 wells, 1966 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.
What individual samples found
Each row summarizes every public sample for that contaminant inside Essex 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 | |
|---|---|---|---|---|---|---|---|
| Arsenic 1987 to 2025 | 41 | 71% | 0% | 0.39 | 7 | 10 ug/L EPA limit |
Sampled fewer than 10 times, too few to summarize: PFOA (6), PFOS (6), Radium (226 + 228) (6), Uranium (5), Sodium (2), Chloride (1), Radon (1).
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What this means
Among homeowners in Essex County who sent a sample to the state lab, the health-based limits most often exceeded were PFOA (17% of 24 wells), arsenic (11% of 231 wells), and total coliform (11% of 231 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.
Manganese and iron 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 Essex County
- Volatile organic compounds (VOCs)8 hazardous waste sites on record locally.
- Metals panel8 hazardous waste sites on record locally.
- Manganese21% of 231 local wells tested were above the New Jersey nuisance level.
- PFOA17% of 24 local wells tested were above the New Jersey limit.
- Iron14% of 231 local wells tested were above the New Jersey nuisance level.
- Arsenic11% of 231 local wells tested were above the New Jersey limit.
- Total coliform11% of 231 local wells tested were above the New Jersey limit (any detection).
- Nitrate<1% of 231 local wells tested were above the New Jersey limit.
- Coliform bacteriaRecommended for every private well, every year.
- RadonMedian local reading is 1,400 pCi/L.
Contamination sources on record in Essex County
NJDEP records 8 hazardous waste sites in Essex County, among 5,239 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.
- 8
- hazardous waste sitesSolvents, degreasers and metals from industrial sites can travel far in fractured bedrock.
- 3,684
- registered underground storage tank sitesRegistered tanks are regulated and inspected; they matter most when they are old or near a shallow well.
- 11
- lined landfills and transfer facilities
- 1,536
- other remediation projects
Treatment that fits the local profile
- PFOA
- Granular activated carbon whole-house; Point-of-use reverse osmosis; Anion exchange
- Arsenic
- Point-of-use reverse osmosis; Adsorptive media (iron-based) whole-house; Anion exchange
- Total coliform
- Inspect and repair the well cap and casing, then shock chlorinate and retest; UV disinfection whole-house; Chlorination system
- Manganese
- Oxidizing filter (greensand, birm) whole-house; Water softener (low levels); Point-of-use reverse osmosis
- Iron
- Oxidizing filter whole-house; Water softener (low levels); Aeration plus filtration
- Chloride
- Point-of-use reverse osmosis; Distillation
Get your Essex 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 Essex County.
Common questions
Is there arsenic in well water in Essex County?
Arsenic was detected in 71% of 41 public well samples in Essex County, and 0% 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 Essex County?
The median radon level across 1 public samples in Essex County was 1,400 pCi/L, with a high of 1,400 pCi/L. New Hampshire recommends treatment above 2,000 pCi/L.
How often should I test a private well in Essex 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 Essex County
- Fairfield township13% arsenic
21 towns have fewer than 30 public samples and are included in the Essex County totals above rather than shown separately: Belleville township, Bloomfield township, Caldwell borough, Cedar Grove township, City of Orange township, East Orange, Essex Fells borough, Glen Ridge borough, Irvington township, Livingston township, Maplewood township, Millburn township, Montclair township, Newark, North Caldwell borough, Nutley township, Roseland borough, South Orange Village township, Verona township, West Caldwell township, West Orange township.
Sources
- USGS Water Quality Portal: 68 samples in Essex 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 Essex County, up to 231 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: 5,239 regulated sites located in Essex 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.