How hard is the water in Rockwall County, TX?

6.3 grains per gallon

Optional: a softener helps, but plenty of homes skip it.

The median hardness measured in Rockwall County, TX is 108 mg/L as calcium carbonate, which is 6.3 gpg. That is moderately hard on the USGS scale. It comes from 471 samples at 6 sites between 2011 and 2023, drawn from every sampling site in the county, wells and surface water together.

How much it varies here

Half the sites came in between 5.9 and 6.8 gpg. The whole middle of that range gives the same answer, so a test of your own tap is unlikely to change it. Confidence in the county figure: medium (how it is measured).

What to do next

At 6.3 gpg this is your call. Look for white film on glasses and crust on the shower head: if you see little of either, you can live without one. If you do want one, a 24,000-grain unit is enough, so ask for that size rather than a bigger one.

More on when a softener is not worth it.

From 5.8 to 7.2 gpg

The softest single sample on record in Rockwall County was 100 mg/L and the hardest 124 mg/L, a 1-fold gap. The top quarter of sites read above 6.8 gpg and the bottom quarter below 5.9 gpg.

What a softener would cost to run

For a household of 3, a 24,000-grain unit covers a week between regenerations. Expect about 138 lb of salt a year (4 bags of 40 lb, about $25), and roughly 2,346 gallons of regeneration water. Installed, most units run $1,000 to $4,500; spread over 15 years with salt, that is about $125 a year.

Sizing at 6.3 gpg

Rockwall County against the rest of Texas

Among the 217 Texas counties with data, Rockwall County is number 168 of 217 counting from the hardest. Across the whole country it is harder than 36% of counties.

Softest in Texas: Nacogdoches County at 0.3 gpg. Hardest: Ward County at 218.5 gpg. Closest to Rockwall County: Polk County (6.5), Cooke County (6), Jackson County (6.1).