How hard is the water in Tangipahoa Parish, LA?

0.5 grains per gallon

You do not need a softener here.

The median hardness measured in Tangipahoa Parish, LA is 9 mg/L as calcium carbonate, which is 0.5 gpg. That is soft on the USGS scale. It comes from 31 samples at 23 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 0.3 and 0.8 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

You can skip the softener. At 0.5 gpg the most a softener would fix is the odd water spot. If a salesperson in Tangipahoa Parish says otherwise, ask to see their reading in grains per gallon and compare it with this one.

More on when a softener is not worth it.

From 0.0 to 5.7 gpg

The softest single sample on record in Tangipahoa Parish was 0.7 mg/L and the hardest 97 mg/L, a 139-fold gap. The top quarter of sites read above 0.8 gpg and the bottom quarter below 0.3 gpg.

Wells 0.5 gpg, rivers and lakes 1.9 gpg

31 groundwater samples from 23 wells put the median at 9.1 mg/L. 841 surface samples from 19 sites put it at 32 mg/L. In Tangipahoa Parish the rivers and lakes come out 1.4 gpg harder. Here the surface water reads harder than the wells, which often points to streams fed by limestone springs or irrigation return flow. The two sources are close, so the county figure should hold whichever one your tap is on.

Tangipahoa Parish against the rest of Louisiana

Among the 64 Louisiana counties with data, Tangipahoa Parish is number 54 of 64 counting from the hardest. Across the whole country it is harder than 3% of counties.

Softest in Louisiana: Lincoln Parish at 0.1 gpg. Hardest: St. Bernard Parish at 53.9 gpg. Closest to Tangipahoa Parish: East Baton Rouge Parish (0.5), East Feliciana Parish (0.4), Vernon Parish (0.6).