How hard is the water in Tensas Parish, LA?
21.8 grains per gallon
A softener will pay its way here.
The median hardness measured in Tensas Parish, LA is 373 mg/L as calcium carbonate, which is 21.8 gpg. That is very hard on the USGS scale. It comes from 11 samples at 11 sites between 1993 and 2022, drawn from groundwater wells, which is what most taps and private wells in the county draw on.
How much it varies here
Half the sites came in between 17.3 and 24 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 21.8 gpg a softener pays its way here. Before you buy, check the quoted unit's grain capacity against the sizing table below, and ask whether it regenerates on demand, which uses less salt than a timer. Call your utility for its own report if you are on city water.
More on sizing a softener for your household.
From 13.2 to 30.6 gpg
The softest single sample on record in Tensas Parish was 226 mg/L and the hardest 523 mg/L, a 2-fold gap. The top quarter of sites read above 24 gpg and the bottom quarter below 17.3 gpg.
Wells 21.8 gpg, rivers and lakes 3.7 gpg
11 groundwater samples from 11 wells put the median at 373 mg/L. 109 surface samples from 7 sites put it at 64 mg/L. In Tensas Parish the wells come out 18.1 gpg harder. Groundwater sits in contact with rock for years and picks up calcium and magnesium as it goes, so wells usually read harder. A utility here that draws from the river can deliver noticeably different water from a private well next door.
What a softener would cost to run
For a household of 3, a 32,000-grain unit covers a week between regenerations. Expect about 476 lb of salt a year (12 bags of 40 lb, about $86), 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 $186 a year.
Sizing at 21.8 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 1,308 | 24,000 | 159 lb |
| 2 | 2,616 | 24,000 | 318 lb |
| 4 | 5,232 | 40,000 | 637 lb |
| 6 | 7,848 | 64,000 | 955 lb |
Tensas Parish against the rest of Louisiana
Among the 64 Louisiana counties with data, Tensas Parish is number 8 of 64 counting from the hardest. Across the whole country it is harder than 88% of counties.
Softest in Louisiana: Lincoln Parish at 0.1 gpg. Hardest: St. Bernard Parish at 53.9 gpg. Closest to Tensas Parish: Madison Parish (21.6), Natchitoches Parish (22.7), Rapides Parish (20.8).