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Well water hardness in Passaic County, New Jersey

8.7 gpg hard

Private wells in Passaic County typically give hard water: the median well sampled by the U.S. Geological Survey has 8.7 gpg (149 mg/L as CaCO₃).

<6060–120120–180>180 mg/L

Wells differ a lot, even next door: one in ten sampled wells had less than 61 mg/L and one in ten more than 445 mg/L. The figure comes from 31 wells and 53 samples taken between 1987 and 2022 (half of them by 1997).

Most samples are older than ten years. Groundwater hardness comes from the rock the well is drilled into and changes slowly, but your own well can be quite different, so treat this as a regional indication and test your water.

On city or town water instead of a well? Your utility publishes its own figures: Suffern (11.3 gpg), Totowa (6.4 gpg), Paterson (10.2 gpg), Little Falls (14.1 gpg), Clifton (6.4 gpg), Passaic (6.4 gpg).

What this hardness means for a well household

How to test your well in New Jersey

Hardness is only one part of a well test. Federal health agencies advise every private well owner to test regularly:

Your county health department can tell you which certified laboratories accept private well samples.

Under the Private Well Testing Act (N.J.S.A. 58:12A-26 et seq.), the buyer or seller must test the well water before sale and review the results before closing, and landlords must test the well water of rental properties.

If no local lab suits you, mail-in kits from certified labs test a wider panel at home; they cost more than a state or county lab.

Treating hard well water

Most households with hard well water install an ion-exchange softener. Test iron and manganese first: above about 0.3 mg/L iron a softener alone is not enough and an iron filter goes in front of it.

Nearby counties

Bergen County9.2 gpgEssex County15.8 gpgMorris County6.8 gpgUnion County12.7 gpgSussex County12.6 gpgOrange County, NY13.3 gpg

FAQ

How hard is well water in Passaic County, New Jersey?

The median well sampled by the USGS in Passaic County has 8.7 gpg (149 mg/L as CaCO₃), which is hard. One in ten wells had less than 61 mg/L and one in ten more than 445 mg/L.

Is my own well the same?

Not necessarily. Hardness depends on the rock layer your well draws from and on its depth, so neighbouring wells can differ by a factor of two or more. Only a test of your own water tells you.

How often should I test my well in New Jersey?

Every year for coliform bacteria, nitrate, total dissolved solids and pH (EPA and CDC advice), and after floods, repairs or a change in taste or smell. Hardness, iron and manganese once, and again before you buy a softener.

Do I need a water softener for my well?

Recommended if you have a water heater, boiler or tankless unit: it saves repairs and detergent.

Where does this figure come from?

From 53 samples of 31 wells measured by the U.S. Geological Survey between 1987 and 2022, retrieved from the Water Quality Portal. We publish a county only when at least 10 wells were sampled.

Source and method

Computed by Water Hardness Atlas from USGS National Water Information System samples (characteristic "Hardness, Ca, Mg", sites of type well, samples since 1980), retrieved 2026-10-29 through the Water Quality Portal. For each well we take the median of its samples, then the median of all wells in the county; wells above 1,000 mg/L (oil, gas or mine brines) are left out. USGS data are in the U.S. public domain. Water Quality Portal query

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