Water hardness in Mendham Township, New Jersey

The published hardness reading for Mendham Township is 167 mg/L, equal to 9.8 grains per gallon — hard water. That number comes from Short Hills Service System and appears in NJ American Water CCR (2025 CCR (PWS ID NJ0712001)).

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.

The supply here is Short Hills System, a regional system reporting 9.8 gpg of hardness for every town it serves, Mendham Township included. That is why 10 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.

With hardness reported at 9.8 gpg, Mendham Township counts as hard. 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 Mendham Township, 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.

Run the arithmetic before committing: softening at this level carries salt, water and servicing costs every year, against slower element scaling and less detergent. Below the hard band that trade rarely pays back on utility alone; above it, the heater replacement usually decides it.

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 Mendham Township, 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.