Well Water Testing in Clinton Township, NJ

Clinton Township was incorporated in 1841, carved from Lebanon Township and named for DeWitt Clinton, the former governor of New York. Today it is better known for Round Valley Reservoir, which reaches roughly 180 feet deep, formed within the ring-shaped diabase ridge of Cushetunk Mountain, an ancient igneous intrusion. Roughly 13,500 people live across nearly 34 square miles, and the township surrounds Lebanon Borough and borders nine other Hunterdon municipalities. It is also one of the busiest places in Hunterdon for well testing, with 928 tests recorded since 2002, and its results are unusual for a reason the map explains.

What well tests in Clinton Township have found

NJDEP's Private Well Testing Act summary (September 2002 to December 2024) covers 928 untreated wells here. Two findings stand out from the county figures.

• Uranium: 2.5% of 243 wells tested for uranium exceeded the limit, the highest rate of any Hunterdon municipality, against 0.5% countywide. It is still a minority, but here the county's uranium requirement is not a formality.
• Gross alpha: 7.7% of 847 wells exceeded the limit (county: 5.8%).
• pH: 40.3% of wells were outside the optimum range (county: 28.1%).
• Arsenic: 3.6%, far below the county's 15.7%.
• Iron and manganese: 19.3% and 9.6% above their nuisance standards.
• Bacteria: total coliform in 23.3%, E. coli in 2.9%.
• PFAS: 4.7% of 106 wells tested since late 2021 (county: 4.4%).

The rock beneath Clinton Township

The township straddles two provinces, and that is why its numbers look like a blend. The NJ Geological Survey's generalized map puts about 42% of the township on the Newark Basin's Triassic sedimentary rock, 34% on Highlands gneiss and granite, 11% on Cambrian limestone and sandstone, and 9% on Jurassic diabase. Across Hunterdon, the Highlands-dominated towns show acidic water and almost no arsenic, while gross alpha runs higher in the Newark Basin towns (about 6.8% of wells against 3.0%), and USGS research names uranium as the dominant alpha emitter in the red mudstone of the Passaic Formation. Clinton Township has a bit of both, and the wells reflect it. Uranium testing entered the panel later than the rest, so its sample is smaller.

Public water or a private well?

About 27.2% of the township lies inside a mapped public water service area (Clinton WD, per NJDEP's 2017 purveyor map). The rest is private well country, and 928 tests show it is well-traveled ground for sales and rentals. Because the boundary between service area and well areas is close to many neighborhoods, confirm the connection type for the specific address. Neighboring Clinton is mostly public water; Raritan Township and Readington Township have far more well tests.

Buying or selling in Clinton Township

Sellers here should expect the test to reflect the ground under their particular lot. Where two rock types meet, a well a few hundred yards away can look quite different. Some practical points:

1. Do not assume the panel will look like the county's. Uranium and gross alpha are more likely to be flagged here than in almost any other Hunterdon town.
2. A radiological result is not automatically a deal-breaker. It usually leads to further analysis to identify which radioactive elements are responsible, and to a discussion of treatment. Ask the lab what follow-up it recommends.
3. Timing matters. A follow-up test adds days. Order early, and ask the lab about turnaround.

Both parties must receive and review the results before closing, and who orders or pays is left to the contract. See PWTA testing and our uranium explainer.

Renting out a property in Clinton Township

Landlords on private wells retest at least every five years and give each tenant a copy within 30 days of receiving the results. A well that showed a borderline radiological result five years ago is worth watching, because a retest is the only way to see whether it has drifted. Tests before December 2021 carry no PFAS result. See landlord testing.

How this compares with neighboring towns

Percent of tested wells above the limit for arsenic and gross alpha, or outside the optimum pH range, with the number of wells behind each figure:

• Raritan Township: arsenic 22.2%, pH 7.2%, gross alpha 11.2% (2,269 wells)
• Readington Township: arsenic 19.1%, pH 11.2%, gross alpha 1.6% (2,067 wells)
• Lebanon Township: arsenic 0.6%, pH 54.4%, gross alpha 2.8% (1,084 wells)
• Tewksbury Township: arsenic 1.8%, pH 52.8%, gross alpha 2.5% (1,024 wells)

Questions from Clinton Township homeowners

Is uranium in my water likely?

Most likely not. Under three percent of tested wells exceeded the limit. It is more common here than elsewhere in Hunterdon, which is why testing is required, but the typical result is a pass.

What does a gross alpha result tell me?

It is a broad screen for naturally occurring radioactivity. An elevated result usually prompts more specific analysis to find the cause, and treatment options exist. Our guide to reading your report explains the lines.

Why do wells nearby test differently?

Because they draw from different rock. See why two wells on the same street can differ.

If I am not selling, should I test anyway?

The New Jersey Department of Health encourages well owners to test at least once for arsenic, mercury, gross alpha and uranium, and every year for total coliform, nitrate and pH. In a township where radiological results are flagged more often than elsewhere in the county, a one-time gross alpha and uranium test is the most useful of those for an owner who has never had one. A homeowner who bought before the requirement took effect may never have been tested.

Also nearby: High Bridge, Lebanon Township, Tewksbury Township and Union Township.