Well Water Treatment in Hillsborough, NJ

Arsenic is the result Hillsborough well owners should read first

The Hillsborough Health Department pulled together the township's Private Well Testing Act data in a 2024 summary. Its headline finding: more than 20% of sampled wells came in over the state arsenic standard, and in some 2-square-mile grids the share climbed as high as 43%, with the worst grids near the Sourland Mountain region.

New Jersey sets the arsenic limit at 5 ppb, which is tighter than the federal number many out-of-state websites quote. A lab report that says 7 or 8 ppb may look small, yet it is above the line that matters here. Arsenic has no taste, color or smell, so a well can seem perfect at the tap and still fail.

None of this says your particular well has a problem. It says arsenic belongs on the short list for any Hillsborough home on a private well, and that an old result from a previous owner is worth repeating if you have not tested since you moved in.

What the township found for PFOS and PFOA

PFNA, PFOA and PFOS were added to the required Private Well Testing Act list on December 1, 2021, so the local data set is still small. In the 2024 summary, 71 Hillsborough wells had been tested for those newer parameters, and more than 10% failed for PFOS and for PFOA.

The state limits are 14 ppt for PFOA and 13 ppt for PFOS. Treatment options include granular activated carbon for the whole house, an under-sink reverse osmosis unit for drinking and cooking, or specialty resin. Whatever you look at, ask for the independent certification that covers PFAS reduction specifically. Our PFAS filtration page explains the standards in more detail.

Iron, manganese and pH: the problems you can see

Several Hillsborough grids topped 10% for iron, manganese, pH, or some mix of the three. These are secondary standards, meaning they are about staining, taste and plumbing wear rather than health limits. Orange rings in a toilet, black specks in a dishwasher, or blue-green marks under a faucet are the usual giveaways.

They still matter for the design of a system. Low pH can eat at copper and will shorten the life of some filter media. Iron and manganese can foul a softener's resin or coat an arsenic cartridge, so they are typically handled earlier in the line.

How a Hillsborough well system is usually put together

Order matters more than brand. A specialist will normally lay out the equipment so each stage protects the next one:

Sediment and pH first

A sediment filter catches grit, and a calcite or similar neutralizer raises acidic water before it reaches anything else.

Iron and manganese next

An oxidizing filter or a softener sized for iron, depending on the levels and the form the iron is in.

Arsenic and PFAS stages

Adsorptive media for arsenic at the point of entry, or an RO unit at the kitchen sink when only drinking water needs it. Arsenic often needs an oxidation step so the media can grab it, which is one reason a speciated test can help.

UV last, if bacteria showed up

Ultraviolet disinfection works only on clear water, so it sits at the end of the train.

Public water in parts of the township

Not every Hillsborough address has a well. New Jersey American Water lists Hillsborough Township in its Somerset County territory. If you pay a water bill to NJ American Water, your supply is regulated and tested by the utility, and its annual water quality report is the place to look. In that case the consultation shifts toward taste, chlorine or chloramine, and hardness instead of arsenic. If you have no water bill, you almost certainly have a well.

Keeping up with the health department's testing advice

Hillsborough's health department recommends testing private wells every year for bacteria and nitrates and testing periodically for the full state list. Treatment does not replace that habit. After a system goes in, a follow-up sample shows whether the arsenic or PFAS stage is actually working, and later samples tell you when media is wearing out.

Selling? The Private Well Testing Act requires a test before closing, and Somerset County samples include uranium on top of the standard list. A buyer will see the numbers, so it helps to know them early.

What your Hillsborough consultation covers

See the well water treatment page for more on each stage, or start the request with the form on this page.

• You send a short request with your ZIP and whether you are on a well or NJ American Water.
• An independent local water treatment provider contacts you, reviews any lab results you already have, and suggests testing for anything missing.
• If lab work is needed, the certified lab's fee is quoted before anything is ordered. The consultation itself costs nothing.
• You get a recommendation matched to your numbers. Installation in New Jersey is plumbing work that must be done by a licensed master plumber or plumbing contractor, and you decide whether to go ahead.