Water hardness in Hillside, New Jersey

Tap water in Hillside measures 9.8 grains per gallon — 167 mg/L as calcium carbonate — which the USGS scale classifies as hard. Expect visible scale on fixtures, spotting on dishes, and shortened service life on water heaters that are never flushed. Ion-exchange softening is generally worth considering at this level.

Source: NJ American Water CCR (2025 CCR (PWS ID NJ0712001)), issued by Short Hills Service System for its Union County customers.

Hillside does not treat its own water: it buys from Short Hills System, which reports hardness of 9.8 gpg across its whole service area. That is why 5 other New Jersey municipalities publish the same number.

See the full Short Hills System water quality report for the complete panel — sodium, chloride, sulfate, fluoride, manganese, iron, pH and total dissolved solids — plus every other town on the system.

At 9.8 gpg, Hillside sits in the hard band. An ion-exchange softener is generally the better fit than a conditioner at this level, because it removes the calcium and magnesium rather than converting them, which is what prevents scale in the water heater as well as on fixtures. A conditioner still helps if brine discharge is restricted or there is no drain nearby.

If you do buy, size the unit against 9.8 gpg and your own household occupancy rather than a county average — capacity and regeneration frequency both come off that pair of numbers.

If you rent in Hillside, the practical version of this is a shower filter, a kettle descaler and a rinse-aid adjustment — the fixed plant belongs to the owner, and a whole-house unit is not yours to install.

Before spending anything in Hillside, price the alternative of doing nothing well: an annual heater flush, a descaler on the kettle and coffee machine, and a corrected detergent dose. That is a holding pattern at this hardness rather than a fix, but it tells you what the equipment actually has to beat.

For the mechanics behind that, what hard water actually is covers the units and scale chemistry, and the Learn hub compares softeners against conditioners in detail.

Short Hills System reports sodium of 5 to 139 ppm — the top of that range, about 139 ppm, is already above the 20 mg/L level the EPA suggests as a guide for people on a physician-ordered 500 mg/day sodium restriction, before any treatment is added at the house.

That matters if softening is on the table in Hillside, because ion exchange trades calcium and magnesium for sodium at roughly 8 mg/L for every grain per gallon removed — on 9.8 gpg that is an added ~78 mg/L on top of what the utility already delivers. Households watching sodium usually leave the kitchen cold tap unsoftened or fit potassium chloride instead.

For the full breakdown, read how much sodium a softener actually adds, which sets out the sources behind it.