Well water hardness in Louisiana

Across 48 counties of Louisiana, the median well sampled by the USGS has 4.6 gpg of hardness. Counties range from 0.3 gpg (West Baton Rouge Parish) to 25.7 gpg (Red River Parish).

Millions of American households drink water from their own well. No utility tests that water and no water quality report covers it. These pages summarise the hardness the U.S. Geological Survey measured in wells county by county, so you know what to expect before you test your own well.

Counties, hardest first

	gpg	mg/L	wells
Red River Parish	25.7	440	30	very hard
West Carroll Parish	25.6	439	13	very hard
Concordia Parish	24.2	414	32	very hard
Natchitoches Parish	22.2	381	40	very hard
Tensas Parish	21.8	373	15	very hard
Madison Parish	20.5	351	12	very hard
Catahoula Parish	19.7	338	48	very hard
Franklin Parish	16.2	277	42	very hard
Morehouse Parish	15.1	259	54	very hard
St. Martin Parish	14.9	255	22	very hard
Iberia Parish	14	239	16	very hard
Acadia Parish	13	222	42	very hard
Vermilion Parish	12	206	60	very hard
Caldwell Parish	10	171	11	hard
St. Landry Parish	9.3	160	71	hard
Jefferson Davis Parish	8.9	152	43	hard
Richland Parish	8.6	148	27	hard
Iberville Parish	8.2	140	13	hard
Evangeline Parish	7.7	132	26	hard
Avoyelles Parish	7.7	131	43	hard
Calcasieu Parish	7	120	178	hard
Cameron Parish	7	120	31	hard
Bossier Parish	6	103	46	moderately hard
Lafayette Parish	5.9	101	54	moderately hard
Rapides Parish	3.3	57	131	soft
Pointe Coupee Parish	2.7	46	24	soft
Ascension Parish	2.6	45	12	soft
Caddo Parish	2.5	43	78	soft
Webster Parish	1.7	30	20	soft
Orleans Parish	1.5	25	16	soft
Jefferson Parish	1.4	24	23	soft
De Soto Parish	0.9	16	77	soft
Beauregard Parish	0.9	16	27	soft
Livingston Parish	0.8	14	28	soft
Bienville Parish	0.7	13	35	soft
Allen Parish	0.7	11	27	soft
Vernon Parish	0.6	10	45	soft
East Feliciana Parish	0.6	10	18	soft
Grant Parish	0.6	10	26	soft
Tangipahoa Parish	0.5	9	33	soft
West Feliciana Parish	0.5	9	13	soft
East Baton Rouge Parish	0.5	9	107	soft
Union Parish	0.4	7	11	soft
Sabine Parish	0.3	5	11	soft
Ouachita Parish	0.3	5	23	soft
St. Helena Parish	0.3	5	20	soft
St. Tammany Parish	0.3	5	49	soft
West Baton Rouge Parish	0.3	5	31	soft

Counties with fewer than 10 sampled wells, or a median outside 5–500 mg/L, are not shown until the figure is reviewed.

Louisiana: tap water hardness by city → · Well water hardness by state and county →