Well water in Sussex County, New Jersey
In Sussex County, 26% of 14,788 private wells tested between 2002 and 2024 had total coliform above the New Jersey limit (any detection), according to NJDEP.
14,793 private wells tested 2002 to 2024 in state summaries; 123 individual samples from 80 wells, 1988 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 | |
|---|---|---|---|---|---|---|---|
| Manganese | 14,793 | 26% | 50 ug/L | ||||
| Total coliform | 14,788 | 26% | |||||
| Iron | 14,793 | 24% | 300 ug/L | ||||
| PFOA | 2,246 | 16% | 14 ng/L | ||||
| PFOS | 2,246 | 15% | 13 ng/L | ||||
| Gross alpha | 5,030 | 12% | 15 pCi/L | ||||
| E. coli Fecal coliform or | 14,704 | 4% | |||||
| Nitrate | 14,792 | 3% | 10 mg/L | ||||
| Arsenic | 10,608 | 2% | 5 ug/L | ||||
| Uranium | 4,488 | 1% | 30 ug/L | ||||
| PFNA | 2,246 | <1% | 13 ng/L |
What individual samples found
Each row summarizes every public sample for that contaminant inside Sussex 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 | |
|---|---|---|---|---|---|---|---|
| Uranium 1999 to 2022 | 31 | 94% | 23% | 1.07 | 623 | 30 ug/L EPA limit | |
| PFOA 2022 to 2025 | 15 | 47% | 13% | 0 | 17 | 4 ng/L EPA limit | |
| PFOS 2022 to 2025 | 15 | 40% | 13% | 0 | 7.3 | 4 ng/L EPA limit | |
| Radium (226 + 228) 1993 to 2022 | 49 | 94% | 4% | 0.171 | 26 | 5 pCi/L EPA limit | |
| Arsenic 1988 to 2025 | 123 | 52% | 2% | 0.08 | 19.7 | 10 ug/L EPA limit | |
| Radon 1998 to 2011 | 59 | 100% | no limit | 1,450 | 90,000 | 2,000 pCi/L health guideline |
Sampled fewer than 10 times, too few to summarize: Nitrate (6), Fluoride (3), Copper (2), Lead (1), Iron (4), Manganese (3), Sodium (1), Chloride (1).
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What this means
Among homeowners in Sussex County who sent a sample to the state lab, the health-based limits most often exceeded were total coliform (26% of 14,788 wells), PFOA (16% of 2,246 wells), and PFOS (15% of 2,246 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 Sussex County
- Volatile organic compounds (VOCs)3 hazardous waste sites on record locally.
- Metals panel3 hazardous waste sites on record locally.
- Manganese26% of 14,793 local wells tested were above the New Jersey nuisance level.
- Total coliform26% of 14,788 local wells tested were above the New Jersey limit (any detection).
- Iron24% of 14,793 local wells tested were above the New Jersey nuisance level.
- Gross alpha12% of 5,030 local wells tested were above the New Jersey limit.
- Radium (226 + 228)4% of 49 local samples were above the limit.
- E. coli4% of 14,704 local wells tested were above the New Jersey limit (any detection).
- Nitrate3% of 14,792 local wells tested were above the New Jersey limit.
- PFNA<1% of 2,246 local wells tested were above the New Jersey limit.
Contamination sources on record in Sussex County
NJDEP records 3 hazardous waste sites in Sussex County, among 883 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.
- 3
- hazardous waste sitesSolvents, degreasers and metals from industrial sites can travel far in fractured bedrock.
- 737
- registered underground storage tank sitesRegistered tanks are regulated and inspected; they matter most when they are old or near a shallow well.
- 10
- lined landfills and transfer facilities
- 133
- 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
- Gross alpha
- Point-of-use reverse osmosis; Water softener (cation exchange) for radium; Anion exchange for uranium
- 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 Sussex 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 Sussex County.
Common questions
Is there arsenic in well water in Sussex County?
Arsenic was detected in 52% of 123 public well samples in Sussex County, and 2% 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 Sussex County?
The median radon level across 59 public samples in Sussex County was 1,450 pCi/L, with a high of 90,000 pCi/L. New Hampshire recommends treatment above 2,000 pCi/L.
How often should I test a private well in Sussex 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 Sussex County
- Andover township25% total coliform
- Byram township20% total coliform
- Frankford township29% total coliform
- Franklin borough24% total coliform
- Fredon township30% total coliform
- Green township29% total coliform
- Hampton township28% total coliform
- Hardyston township23% total coliform
- Hopatcong borough60% pfoa
- Lafayette township28% total coliform
- Montague township23% total coliform
- Sandyston township23% total coliform
- Sparta township18% total coliform
- Stillwater township31% total coliform
- Vernon township24% total coliform
- Wantage township30% total coliform
8 towns have fewer than 30 public samples and are included in the Sussex County totals above rather than shown separately: Andover borough, Branchville borough, Hamburg borough, Newton, Ogdensburg borough, Stanhope borough, Sussex borough, Walpack township.
Sources
- USGS Water Quality Portal: 313 samples in Sussex 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 Sussex County, up to 14,793 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: 883 regulated sites located in Sussex 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.