How hard is the water in Caldwell Parish, LA?
11.2 grains per gallon
A softener will pay its way here.
The median hardness measured in Caldwell Parish, LA is 193 mg/L as calcium carbonate, which is 11.2 gpg. That is very hard on the USGS scale. It comes from 24 samples at 8 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 7.6 and 13.7 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 11.2 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. Because Caldwell Parish straddles a decision line, check your own tap with a $10 test strip before you spend anything.
More on sizing a softener for your household.
From 0.1 to 25.2 gpg
The softest single sample on record in Caldwell Parish was 2.1 mg/L and the hardest 431 mg/L, a 205-fold gap. The top quarter of sites read above 13.7 gpg and the bottom quarter below 7.6 gpg. So even here some sites draw water soft enough to need nothing at all.
Wells 11.2 gpg, rivers and lakes 2.1 gpg
24 groundwater samples from 8 wells put the median at 192.5 mg/L. 170 surface samples from 6 sites put it at 36.4 mg/L. In Caldwell Parish the wells come out 9.1 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 24,000-grain unit covers a week between regenerations. Expect about 246 lb of salt a year (7 bags of 40 lb, about $44), 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 $144 a year.
Sizing at 11.2 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 672 | 24,000 | 82 lb |
| 2 | 1,344 | 24,000 | 164 lb |
| 4 | 2,688 | 24,000 | 327 lb |
| 6 | 4,032 | 32,000 | 491 lb |
Caldwell Parish against the rest of Louisiana
Among the 64 Louisiana counties with data, Caldwell Parish is number 22 of 64 counting from the hardest. Across the whole country it is harder than 56% of counties.
Softest in Louisiana: Lincoln Parish at 0.1 gpg. Hardest: St. Bernard Parish at 53.9 gpg. Closest to Caldwell Parish: St. Charles Parish (11.4), Vermilion Parish (10.9), Jefferson Parish (10.5).