Gross alpha in New Jersey well water
In New Jersey, 11% of 99,698 private wells tested between 2002 and 2024 had gross alpha above the New Jersey limit (15 pCi/L), according to NJDEP.
Gross alpha is a screening test for radioactive elements in water, mainly radium and uranium from granite bedrock. A high result means one of those is present and the specific test should follow. Alpha emitters raise cancer risk when swallowed over years.
Check your gross alpha number
Type the value from your lab report. It is compared to the New Jersey limit and the EPA limit, the same way the full interpretation does it.
Getting it fixed
Book a free in-home water test with a licensed local company, or see the treatment guide for what removes gross alpha.
By county, from homeowner tests
Share of private wells above the state guidance level (15 pCi/L) in tests homeowners sent to the state lab, 2002 to 2024.
| County | Wells tested | Above state level | Highest | |
|---|---|---|---|---|
| Camden | 3,566 | 36% | ||
| Cumberland | 8,308 | 31% | ||
| Salem | 4,950 | 17% | ||
| Middlesex | 325 | 13% | ||
| Gloucester | 9,041 | 13% | ||
| Sussex | 5,030 | 12% | ||
| Passaic | 1,710 | 12% | ||
| Atlantic | 7,740 | 11% | ||
| Burlington | 11,690 | 10% | ||
| Somerset | 2,111 | 8% | ||
| Mercer | 3,179 | 6% | ||
| Hunterdon | 12,490 | 6% | ||
| Warren | 2,551 | 6% | ||
| Ocean | 8,174 | 5% | ||
| Morris | 4,291 | 4% |
Towns with the highest share above the state level
- Shiloh borough, Cumberland County67% of 99 wells
- Upper Deerfield township, Cumberland County63% of 1,068 wells
- Hopewell township, Cumberland County59% of 762 wells
- Buena borough, Atlantic County51% of 45 wells
- Deerfield township, Cumberland County49% of 617 wells
- Waterford township, Camden County46% of 1,478 wells
- Stow Creek township, Cumberland County44% of 239 wells
- Vineland, Cumberland County42% of 1,165 wells
- Pittsgrove township, Salem County41% of 1,380 wells
- Winslow township, Camden County39% of 1,391 wells
- Hammonton, Atlantic County33% of 438 wells
- Clayton borough, Gloucester County30% of 43 wells
- West Windsor township, Mercer County28% of 134 wells
- Vernon township, Sussex County28% of 1,054 wells
- Upper Pittsgrove township, Salem County27% of 509 wells
- Greenwich township, Cumberland County27% of 158 wells
- Tabernacle township, Burlington County26% of 1,296 wells
- Fairfield township, Cumberland County24% of 734 wells
- Independence township, Warren County23% of 166 wells
- Franklin township, Gloucester County21% of 3,104 wells
- Buena Vista township, Atlantic County21% of 1,155 wells
- Evesham township, Burlington County21% of 542 wells
- Oldmans township, Salem County20% of 216 wells
- Shamong township, Burlington County20% of 1,089 wells
- Logan township, Gloucester County19% of 72 wells
Sources
- NJDEP Private Well Testing Act summaries: 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.