How hard is the water in Grant Parish, LA?
28.4 grains per gallon
A softener will pay its way here.
The median hardness measured in Grant Parish, LA is 487 mg/L as calcium carbonate, which is 28.4 gpg. That is very hard on the USGS scale. It comes from 86 samples at 11 sites between 1990 and 2024, 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 22.8 and 33.2 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: high (how it is measured).
What to do next
At 28.4 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 0.6 to 71.6 gpg
The softest single sample on record in Grant Parish was 9.7 mg/L and the hardest 1,225 mg/L, a 126-fold gap. The top quarter of sites read above 33.2 gpg and the bottom quarter below 22.8 gpg. So even here some sites draw water soft enough to need nothing at all.
Wells 28.4 gpg, rivers and lakes 1.4 gpg
86 groundwater samples from 11 wells put the median at 487 mg/L. 361 surface samples from 9 sites put it at 24 mg/L. In Grant Parish the wells come out 27.0 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 40,000-grain unit covers a week between regenerations. Expect about 621 lb of salt a year (16 bags of 40 lb, about $112), 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 $212 a year.
Sizing at 28.4 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 1,704 | 24,000 | 207 lb |
| 2 | 3,408 | 24,000 | 415 lb |
| 4 | 6,816 | 48,000 | 829 lb |
| 6 | 10,224 | 80,000 | 1,244 lb |
Grant Parish against the rest of Louisiana
Among the 64 Louisiana counties with data, Grant Parish is number 4 of 64 counting from the hardest. Across the whole country it is harder than 94% of counties.
Softest in Louisiana: Lincoln Parish at 0.1 gpg. Hardest: St. Bernard Parish at 53.9 gpg. Closest to Grant Parish: Red River Parish (25.9), West Carroll Parish (25.6), Natchitoches Parish (22.7).