How hard is the water in St. Bernard Parish, LA?

53.9 grains per gallon

A softener will pay its way here.

The median hardness measured in St. Bernard Parish, LA is 923 mg/L as calcium carbonate, which is 53.9 gpg. That is very hard on the USGS scale. It comes from 912 samples at 20 sites between 2006 and 2023, drawn from every sampling site in the county, wells and surface water together.

How much it varies here

Half the sites came in between 42.1 and 137.1 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 53.9 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 28.3 to 204.5 gpg

The softest single sample on record in St. Bernard Parish was 485 mg/L and the hardest 3,500 mg/L, a 7-fold gap. The top quarter of sites read above 137.1 gpg and the bottom quarter below 42.1 gpg.

What a softener would cost to run

For a household of 3, a 80,000-grain unit covers a week between regenerations. Expect about 1,177 lb of salt a year (30 bags of 40 lb, about $212), 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 $312 a year.

Sizing at 53.9 gpg

St. Bernard Parish against the rest of Louisiana

Among the 64 Louisiana counties with data, St. Bernard Parish is the hardest. Across the whole country it is harder than 98% of counties.

Softest in Louisiana: Lincoln Parish at 0.1 gpg. Closest to St. Bernard Parish: Orleans Parish (44.1), Cameron Parish (36), Grant Parish (28.4).