Water hardness in Demarest, New Jersey

Demarest water tests at 136 mg/L of hardness, or about 8 grains per gallon: hard by the standard USGS classification. The figure is published by Veolia Hackensack Service System, which serves the town, in Veolia Water New Jersey Hackensack 2024 Annual Water Quality Report (PWSID NJ0238001) (2025 (2024 data)).

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 Veolia Hackensack System, a regional system reporting 8 gpg of hardness for every town it serves, Demarest included. That is why 50 other New Jersey municipalities publish the same number.

See the full Veolia Hackensack 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 8 gpg, Demarest 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.

Some Demarest addresses sit off the main and run on their own wells. This figure does not apply to them at all: a private well needs its own hardness, iron and pH panel, and two wells on the same street can differ.

Veolia Hackensack System treats surface water, so its report also carries disinfection byproducts alongside the mineral figures. Softening does nothing to those — if chlorine taste is part of the complaint in Demarest, carbon filtration is the part that answers it.

Before spending anything in Demarest, 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.

Veolia Hackensack System reports sodium of 86 ppm (above NJ recommended upper limit of 50 ppm) — the top of that range, about 86 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 Demarest, because ion exchange trades calcium and magnesium for sodium at roughly 8 mg/L for every grain per gallon removed — on 8 gpg that is an added ~64 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.