Well water in Cumberland County, New Jersey
In Cumberland County, 13% of 8,423 private wells tested between 2002 and 2024 had nitrate above the New Jersey limit (10 mg/L), according to NJDEP.
8,423 private wells tested 2002 to 2024 in state summaries; 289 individual samples from 134 wells, 1970 to 2024. 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 | |
|---|---|---|---|---|---|---|---|
| Gross alpha | 8,308 | 31% | 15 pCi/L | ||||
| Iron | 8,423 | 27% | 300 ug/L | ||||
| Manganese | 8,423 | 15% | 50 ug/L | ||||
| Nitrate | 8,423 | 13% | 10 mg/L | ||||
| Total coliform | 8,366 | 8% | |||||
| PFOA | 1,674 | 4% | 14 ng/L | ||||
| PFOS | 1,674 | 3% | 13 ng/L | ||||
| E. coli Fecal coliform or | 8,364 | <1% | |||||
| Arsenic | 3,499 | <1% | 5 ug/L | ||||
| PFNA | 1,674 | <1% | 13 ng/L |
What individual samples found
Each row summarizes every public sample for that contaminant inside Cumberland 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 2020 to 2023 | 18 | 50% | 44% | 1 | 15 | 4 ng/L EPA limit | |
| PFOS 2020 to 2023 | 18 | 33% | 22% | 0 | 43 | 4 ng/L EPA limit | |
| Radium (226 + 228) 1988 to 2022 | 244 | 95% | 12% | 2.55 | 14 | 5 pCi/L EPA limit | |
| Arsenic 1974 to 2024 | 289 | 41% | 1% | 0 | 24.1 | 10 ug/L EPA limit | |
| Uranium 1988 to 2022 | 127 | 48% | 0% | 0 | 1.46 | 30 ug/L EPA limit | |
| Radon 1988 to 2024 | 135 | 96% | no limit | 280 | 3,900 | 2,000 pCi/L health guideline |
Sampled fewer than 10 times, too few to summarize: Nitrate (7), Copper (4), Fluoride (2), Lead (2), Manganese (3), Sodium (2), Iron (2), Chloride (1).
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What this means
Among homeowners in Cumberland County who sent a sample to the state lab, the health-based limits most often exceeded were nitrate (13% of 8,423 wells), total coliform (8% of 8,366 wells), and PFOA (4% of 1,674 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 Cumberland County
- Volatile organic compounds (VOCs)4 hazardous waste sites on record locally.
- Metals panel4 hazardous waste sites on record locally.
- Gross alpha31% of 8,308 local wells tested were above the New Jersey limit.
- Iron27% of 8,423 local wells tested were above the New Jersey nuisance level.
- Manganese15% of 8,423 local wells tested were above the New Jersey nuisance level.
- Nitrate13% of 8,423 local wells tested were above the New Jersey limit.
- Radium (226 + 228)12% of 244 local samples were above the limit.
- Total coliform8% of 8,366 local wells tested were above the New Jersey limit (any detection).
- E. coli<1% of 8,364 local wells tested were above the New Jersey limit (any detection).
- PFNA<1% of 1,674 local wells tested were above the New Jersey limit.
Contamination sources on record in Cumberland County
NJDEP records 4 hazardous waste sites in Cumberland County, among 1,095 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.
- 4
- hazardous waste sitesSolvents, degreasers and metals from industrial sites can travel far in fractured bedrock.
- 875
- registered underground storage tank sitesRegistered tanks are regulated and inspected; they matter most when they are old or near a shallow well.
- 14
- lined landfills and transfer facilities
- 202
- other remediation projects
Treatment that fits the local profile
- Nitrate
- Point-of-use reverse osmosis; Anion exchange; Distillation
- Total coliform
- Inspect and repair the well cap and casing, then shock chlorinate and retest; UV disinfection whole-house; Chlorination system
- Gross alpha
- Point-of-use reverse osmosis; Water softener (cation exchange) for radium; Anion exchange for uranium
- 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
- PFOA
- Granular activated carbon whole-house; Point-of-use reverse osmosis; Anion exchange
Get your Cumberland 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 Cumberland County.
Common questions
Is there arsenic in well water in Cumberland County?
Arsenic was detected in 41% of 289 public well samples in Cumberland 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 Cumberland County?
The median radon level across 135 public samples in Cumberland County was 280 pCi/L, with a high of 3,900 pCi/L. New Hampshire recommends treatment above 2,000 pCi/L.
How often should I test a private well in Cumberland 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 Cumberland County
- Commercial township9% total coliform
- Deerfield township26% nitrate
- Downe township12% total coliform
- Fairfield township8% nitrate
- Greenwich township12% total coliform
- Hopewell township16% nitrate
- Lawrence township8% total coliform
- Maurice River township10% total coliform
- Millville5% nitrate
- Shiloh borough29% nitrate
- Stow Creek township12% nitrate
- Upper Deerfield township25% nitrate
- Vineland26% nitrate
1 towns have fewer than 30 public samples and are included in the Cumberland County totals above rather than shown separately: Bridgeton.
Sources
- USGS Water Quality Portal: 854 samples in Cumberland 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 10 contaminants in Cumberland County, up to 8,423 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: 1,095 regulated sites located in Cumberland 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.