How hard is the water in Luna County, NM?
4.1 grains per gallon
Optional: a softener helps, but plenty of homes skip it.
The median hardness measured in Luna County, NM is 71 mg/L as calcium carbonate, which is 4.1 gpg. That is moderately hard on the USGS scale. It comes from 8 samples at 5 sites between 2009 and 2014, drawn from every sampling site in the county, wells and surface water together.
How much it varies here
Half the sites came in between 2.2 and 5.3 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 4.1 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 Luna 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 1.3 to 11.6 gpg
The softest single sample on record in Luna County was 21.8 mg/L and the hardest 198 mg/L, a 9-fold gap. The top quarter of sites read above 5.3 gpg and the bottom quarter below 2.2 gpg.
Wells 3.2 gpg, rivers and lakes 11.6 gpg
4 groundwater samples from 4 wells put the median at 54.3 mg/L. 4 surface samples from 1 sites put it at 198 mg/L. In Luna County the rivers and lakes come out 8.4 gpg harder. Here the surface water reads harder than the wells, which often points to streams fed by limestone springs or irrigation return flow. A utility here that draws from the aquifer can deliver noticeably different water from a private well next door.
What a softener would cost to run
For a household of 3, a 24,000-grain unit covers a week between regenerations. Expect about 90 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 4.1 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 246 | 24,000 | 30 lb |
| 2 | 492 | 24,000 | 60 lb |
| 4 | 984 | 24,000 | 120 lb |
| 6 | 1,476 | 24,000 | 180 lb |
Luna County against the rest of New Mexico
Among the 33 New Mexico counties with data, Luna County is number 32 of 33 counting from the hardest. Across the whole country it is harder than 27% of counties.
Softest in New Mexico: Rio Arriba County at 2.3 gpg. Hardest: Chaves County at 116.2 gpg. Closest to Luna County: Los Alamos County (4.6), Taos County (4.9), Catron County (5.1).