How hard is the water in Robertson County, TX?
4 grains per gallon
Optional: a softener helps, but plenty of homes skip it.
The median hardness measured in Robertson County, TX is 69 mg/L as calcium carbonate, which is 4 gpg. That is moderately hard on the USGS scale. It comes from 57 samples at 4 sites between 1990 and 2011, drawn from every sampling site in the county, wells and surface water together.
How much it varies here
Half the sites came in between 2.9 and 5.7 gpg. That spread crosses a decision line, so some homes here land on a different answer. A $10 test strip on your own tap settles it. Confidence in the county figure: medium (how it is measured).
What to do next
At 4 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. Because Robertson County straddles a decision line, check your own tap with a $10 test strip before you spend anything.
More on when a softener is not worth it.
From 0.2 to 9.9 gpg
The softest single sample on record in Robertson County was 4 mg/L and the hardest 169 mg/L, a 42-fold gap. The top quarter of sites read above 5.7 gpg and the bottom quarter below 2.9 gpg.
Wells 3.8 gpg, rivers and lakes 4.3 gpg
5 groundwater samples from 3 wells put the median at 64.9 mg/L. 52 surface samples from 1 sites put it at 73.7 mg/L. In Robertson County the rivers and lakes come out 0.5 gpg harder. Here the surface water reads harder than the wells, which often points to streams fed by limestone springs or irrigation return flow. The two sources are close, so the county figure should hold whichever one your tap is on.
What a softener would cost to run
For a household of 3, a 24,000-grain unit covers a week between regenerations. Expect about 88 lb of salt a year (3 bags of 40 lb, about $16), 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 $116 a year.
Sizing at 4 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 240 | 24,000 | 29 lb |
| 2 | 480 | 24,000 | 58 lb |
| 4 | 960 | 24,000 | 117 lb |
| 6 | 1,440 | 24,000 | 175 lb |
Robertson County against the rest of Texas
Among the 217 Texas counties with data, Robertson County is number 184 of 217 counting from the hardest. Across the whole country it is harder than 26% of counties.
Softest in Texas: Nacogdoches County at 0.3 gpg. Hardest: Ward County at 218.5 gpg. Closest to Robertson County: Hardin County (4), Wilson County (4.1), Jasper County (3.8).