Do you need a water softener on city water? Check the number first

The answer for most city-water homes here

The U.S. Geological Survey classifies water under 60 mg/L of hardness as soft, 61–120 as moderately hard, 121–180 as hard, and over 180 as very hard.^[source] Every local utility that reported a hardness value in its 2025 water quality report falls in the soft band, most of them well under half the cutoff.

Many other utilities, including Concord, Gastonia, Mooresville and Monroe, don't print a hardness value in their reports. If yours is one of them, call the utility and ask; they measure it. Union County's number covers only the Catawba River water it buys, not its Lake Tillery supply.^[source] Your town page under service areas shows what your utility reports.

"But I have spots and scale"

Soft water still contains some dissolved minerals; Charlotte Water's total dissolved solids averaged 59 ppm in 2025.^[source] When water evaporates on glass or a shower door, whatever was dissolved stays behind as a faint film. That's normal and isn't a hardness problem a softener is built to solve. A few things worth checking first:

• Spots on glassware: often dishwasher detergent, rinse aid or load-related; changing those is cheaper than any equipment.
• Shower door film: a squeegee after showering handles most of it.
• Crust in a water heater or kettle: on soft water, have a plumber look at the heater's age and anode before buying treatment.
• White flakes from a faucet aerator: sometimes a deteriorating water-heater dip tube rather than the water itself.

When a softener might still make sense on city water

Essentially one case: a test shows your water is hard. That could happen if your utility's number is borderline and rising, if you're served by a system that doesn't report hardness and turns out to be harder, or if you're on a private well and only think you're on city water. A hardness test settles it; the water testing page explains the options, and the softener page covers sizing and certification (NSF/ANSI 44) when a softener really is the answer.

If you're on a private well, the picture is different: three USGS monitoring wells in Union County, for instance, ranged from 30 to 151 mg/L, soft to hard.^[source] See well water treatment instead.

If someone says you need a softener

1. Step 1

   Ask for the number

   A real recommendation comes with a measured hardness in mg/L or grains per gallon. A color-change demo, a TDS meter or a "precipitation" test isn't a hardness measurement.

2. Step 2

   Compare it to your utility's report

   If the number they quote doesn't match the report, ask why.

3. Step 3

   Check the USGS scale

   Under 60 mg/L as calcium carbonate is soft.^[source] If the number is quoted in grains per gallon, ask them to convert it to mg/L so you can compare it with your utility's report.

4. Step 4

   Take your time

   In North Carolina, home-solicitation sales come with a right to cancel within three business days.^[source]

Selling softeners to soft-water homes is on our list of things we won't sell you. If you're on city water and want better water, the more useful options are usually whole-home carbon or kitchen-tap reverse osmosis.

If you do need one

A whole-house softener connects to your main line and needs a drain, which is licensed plumbing work. Here's how installation works.