How hard is the water in Assumption Parish, LA?
7.6 grains per gallon
A softener is worth it here.
The median hardness measured in Assumption Parish, LA is 130 mg/L as calcium carbonate, which is 7.6 gpg. That is hard on the USGS scale. It comes from 158 samples at 8 sites between 1993 and 2021, drawn from every sampling site in the county, wells and surface water together.
How much it varies here
Half the sites came in between 6.3 and 8.5 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 7.6 gpg a softener is worth getting, mainly to protect the water heater and cut soap use. Get at least two quotes, ask each installer what grain capacity they are fitting, and check it against the sizing table below. Because Assumption 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 5.1 to 16.4 gpg
The softest single sample on record in Assumption Parish was 88 mg/L and the hardest 280 mg/L, a 3-fold gap. The top quarter of sites read above 8.5 gpg and the bottom quarter below 6.3 gpg.
Wells 16.4 gpg, rivers and lakes 7.2 gpg
1 groundwater samples from 1 wells put the median at 280 mg/L. 157 surface samples from 7 sites put it at 123 mg/L. In Assumption Parish the wells come out 9.2 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 165 lb of salt a year (5 bags of 40 lb, about $30), 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 $130 a year.
Sizing at 7.6 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 456 | 24,000 | 55 lb |
| 2 | 912 | 24,000 | 111 lb |
| 4 | 1,824 | 24,000 | 222 lb |
| 6 | 2,736 | 24,000 | 333 lb |
Assumption Parish against the rest of Louisiana
Among the 64 Louisiana counties with data, Assumption Parish is number 35 of 64 counting from the hardest. Across the whole country it is harder than 41% of counties.
Softest in Louisiana: Lincoln Parish at 0.1 gpg. Hardest: St. Bernard Parish at 53.9 gpg. Closest to Assumption Parish: Morehouse Parish (7.7), Pointe Coupee Parish (7.7), Iberville Parish (7.8).