How hard is the water in Plaquemines Parish, LA?
13 grains per gallon
A softener will pay its way here.
The median hardness measured in Plaquemines Parish, LA is 222 mg/L as calcium carbonate, which is 13 gpg. That is very hard on the USGS scale. It comes from 1,114 samples at 15 sites between 1990 and 2024, drawn from every sampling site in the county, wells and surface water together.
How much it varies here
Half the sites came in between 10.3 and 100.7 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: high (how it is measured).
What to do next
At 13 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 Plaquemines 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 8.4 to 171.9 gpg
The softest single sample on record in Plaquemines Parish was 143 mg/L and the hardest 2,943 mg/L, a 21-fold gap. The top quarter of sites read above 100.7 gpg and the bottom quarter below 10.3 gpg.
What a softener would cost to run
For a household of 3, a 24,000-grain unit covers a week between regenerations. Expect about 283 lb of salt a year (8 bags of 40 lb, about $51), 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 $151 a year.
Sizing at 13 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 780 | 24,000 | 95 lb |
| 2 | 1,560 | 24,000 | 190 lb |
| 4 | 3,120 | 24,000 | 380 lb |
| 6 | 4,680 | 40,000 | 569 lb |
Plaquemines Parish against the rest of Louisiana
Among the 64 Louisiana counties with data, Plaquemines Parish is number 20 of 64 counting from the hardest. Across the whole country it is harder than 62% of counties.
Softest in Louisiana: Lincoln Parish at 0.1 gpg. Hardest: St. Bernard Parish at 53.9 gpg. Closest to Plaquemines Parish: Acadia Parish (13.1), Iberia Parish (14), St. Charles Parish (11.4).