Well water test results in Somerset County, New Jersey
When a home with a private well is sold in New Jersey, the well must be tested and results go to the state (NJDEP). This page shows NJDEP's official summary for Somerset County: the share of tested wells that exceeded a standard, from September 2002 to December 2024.
Highest health-related exceedance rates here: arsenic (16.2%), pfas (15.7%), gross alpha (7.5%). Your own well can be very different from the county average, so only a test of your water tells you what's in it.
Percent of tested wells over the standard
| Test | Wells over the standard | Standard used |
|---|---|---|
| Arsenic | 16.2% of 7,432 wells sampled | 5 µg/L |
| Gross alpha (radioactivity) | 7.5% of 2,111 wells sampled | 15 pCi/L |
| Nitrate | 0.4% of 7,437 wells sampled | 10 mg/L |
| Fecal coliform or E. coli | 4.1% of 7,423 wells sampled | |
| Total coliform | 24% of 7,433 wells sampled | |
| VOCs (fuel and solvent chemicals) | 1.4% of 7,436 wells sampled | |
| Mercury | Testing is not required under PWTA | |
| Uranium | 0.1% of 1732 wells sampled | 30 µg/L |
| PFAS (PFOA, PFOS, PFNA) | 15.7% of 911 wells sampled | |
| SOCs (pesticides and other synthetic chemicals) | 0.2% of 1,748 wells sampled | |
| Iron | 9.3% of 7,437 wells sampled | 0.3 mg/L |
| Manganese | 6.6% of 7,437 wells sampled | 0.05 mg/L |
| pH outside optimum range | 14.1% of 7,435 wells sampled |
Figures copied from NJDEP's county summary. Coliform rows show wells where bacteria were present. pH shows wells outside the optimum range. 'Testing is not required under PWTA' means the state doesn't require that test in this county, so no county figure exists.
What to test for here
New Jersey's required sale test covers bacteria, nitrate, pH, iron, manganese, lead, arsenic, gross alpha, PFOA/PFOS/PFNA and VOCs/SOCs; mercury and uranium are required only in some counties. If you aren't buying or selling, the same list is a good yearly guide. Find a state-certified lab with NJDEP DataMiner or our New Jersey lab page.
Questions
Is well water in Somerset County high in arsenic or radioactivity?
NJDEP data for 2002–2024: arsenic: 16.2%, 7,432 wells sampled; gross alpha: 7.5%, 2,111 wells sampled. County figures are averages; test your own well.
Do I have to test my well when selling a house in Somerset County?
Yes. New Jersey's Private Well Testing Act requires the buyer or seller to test the well before closing, and landlords must test too.
Where do these numbers come from?
NJDEP's Private Well Testing Act county summary, published as open data. Counties with fewer than ten wells sampled aren't reported.
Sources
- NJDEP: Private Well Testing Act summary results by county (open data, Sept 2002 to Dec 2024)
- NJDEP: PWTA data summary map
- NJDEP: Private Well Testing Act (what must be tested)
- NJDEP: Certified laboratory search (DataMiner)
Other New Jersey counties
Atlantic County · Bergen County · Burlington County · Camden County · Cape May County · Cumberland County · Essex County · Gloucester County · Hunterdon County · Mercer County · Middlesex County · Monmouth County · Morris County · Ocean County · Passaic County · Salem County · Sussex County · Warren County