Water Hardness in Louisiana
Across 25 measured cities — with 253 more covered by labeled county-level estimates — Louisiana's median tap water hardness is 134.7 mg/L (7.9 gpg): hard on the USGS scale. Below: every covered city, the state's hardest and softest water, and the geology that explains it.
Data updated July 6, 2026. Sources: utility-reported water quality data and USGS/EPA Water Quality Portal samples.
State Median
134.7
mg/L (7.9 gpg), measured cities
Measured Range
3.9-211.0
mg/L across measured cities
Measured Cities
25
utility-reported or computed values
County Estimates
253
91% of covered cities
Louisiana Cities by Hardness Category
Measured cities only — labeled county estimates never enter the category counts or the median.
| Category | Range | Measured cities | Share |
|---|---|---|---|
| Soft | 0-60 mg/L | 8 | 32.0% |
| Moderately hard | 60-120 mg/L | 4 | 16.0% |
| Hard | 120-180 mg/L | 11 | 44.0% |
| Very hard | >180 mg/L | 2 | 8.0% |
Hardest and Softest Water in Louisiana
Measured values only; labeled county estimates and values under active dispute never rank.
Hardest water in Louisiana
- Carlyss — 211.0 mg/L (12.3 gpg), very hard
- Sulphur — 211.0 mg/L (12.3 gpg), very hard
- Broussard — 159.0 mg/L (9.3 gpg), hard
- Bridge City — 154.0 mg/L (9.0 gpg), hard
- Elmwood — 154.0 mg/L (9.0 gpg), hard
Softest water in Louisiana
- Covington — 3.9 mg/L (0.2 gpg), soft
- Port Allen — 18.6 mg/L (1.1 gpg), soft
- Baton Rouge — 23.4 mg/L (1.4 gpg), soft
- Lakeview — 46.7 mg/L (2.7 gpg), soft
- Shreveport — 46.7 mg/L (2.7 gpg), soft
Every Covered City in Louisiana
All 278 covered Louisiana cities, sorted by population served. "County estimate" rows are labeled context values from USGS/EPA Water Quality Portal county sampling — they never enter the median above. City names link to each city's full water quality page.
| City | Hardness (mg/L) | gpg | Category | Data |
|---|---|---|---|---|
| Baton Rouge | 23.4 | 1.4 | Soft | Utility-reported |
| Belle Chasse | 153.0 | 8.9 | Hard | Utility-reported |
| New Orleans | 153.2 | 9.0 | Hard | Utility-reported |
| Metairie | 134.7 | 7.9 | Hard | Utility-reported |
| Gretna | 153.0 | 8.9 | Hard | Utility-reported |
| Marrero | 154.0 | 9.0 | Hard | Utility-reported |
| Shreveport | 46.7 | 2.7 | Soft | Utility-reported |
| Lakeview | 46.7 | 2.7 | Soft | Utility-reported |
| Barataria | 186.0 | 10.9 | Very hard | County estimate |
| Lafitte | 186.0 | 10.9 | Very hard | County estimate |
| Lafayette | 102.4 | 6.0 | Moderately hard | Utility-reported |
| Carencro | 99.0 | 5.8 | Moderately hard | Utility-reported |
| Scott | 99.0 | 5.8 | Moderately hard | Utility-reported |
| Ossun | 99.0 | 5.8 | Moderately hard | Utility-reported |
| Monroe | 54.5 | 3.2 | Soft | Utility-reported |
| Houma | 360.0 | 21.1 | Very hard | County estimate |
| Lake Charles | 120.5 | 7.0 | Hard | County estimate |
| Gray | 360.0 | 21.1 | Very hard | County estimate |
| Bossier City | 48.0 | 2.8 | Soft | County estimate |
| Denham Springs | 26.0 | 1.5 | Soft | County estimate |
| Port Allen | 18.6 | 1.1 | Soft | Utility-reported |
| Larose | 163.0 | 9.5 | Hard | County estimate |
| Lockport | 163.0 | 9.5 | Hard | County estimate |
| West Monroe | 27.4 | 1.6 | Soft | County estimate |
| Covington | 3.9 | 0.2 | Soft | Utility-reported |
| Alexandria | 26.0 | 1.5 | Soft | County estimate |
| Natalbany | 27.0 | 1.6 | Soft | County estimate |
| Westwego | 154.0 | 9.0 | Hard | Utility-reported |
| Lakeshore | 54.5 | 3.2 | Soft | Utility-reported |
| Sterlington | 21.4 | 1.3 | Soft | County estimate |
| Luling | 188.0 | 11.0 | Very hard | County estimate |
| Bridge City | 154.0 | 9.0 | Hard | Utility-reported |
| Elmwood | 154.0 | 9.0 | Hard | Utility-reported |
| Jefferson | 154.0 | 9.0 | Hard | Utility-reported |
| Mandeville | 47.8 | 2.8 | Soft | Utility-reported |
| Pineville | 26.0 | 1.5 | Soft | County estimate |
| Opelousas | 72.0 | 4.2 | Moderately hard | County estimate |
| Carlyss | 211.0 | 12.3 | Very hard | Utility-reported |
| Ruston | 20.0 | 1.2 | Soft | County estimate |
| Sulphur | 211.0 | 12.3 | Very hard | Utility-reported |
| Hammond | 27.0 | 1.6 | Soft | County estimate |
| Ball | 26.0 | 1.5 | Soft | County estimate |
| Zachary | 55.1 | 3.2 | Soft | County estimate |
| Maurice | 132.0 | 7.7 | Hard | County estimate |
| Longville | 24.0 | 1.4 | Soft | County estimate |
| Bastrop | 33.0 | 1.9 | Soft | County estimate |
| Minden | 25.0 | 1.5 | Soft | County estimate |
| New Roads | 136.0 | 8.0 | Hard | County estimate |
| Napoleonville | 96.0 | 5.6 | Moderately hard | County estimate |
| Gonzales | 66.1 | 3.9 | Moderately hard | County estimate |
| Thibodaux | 163.0 | 9.5 | Hard | County estimate |
| Duson | 84.1 | 4.9 | Moderately hard | County estimate |
| Blanchard | 55.4 | 3.2 | Soft | County estimate |
| Morgan City | 96.0 | 5.6 | Moderately hard | County estimate |
| Abbeville | 132.0 | 7.7 | Hard | County estimate |
| Perry | 132.0 | 7.7 | Hard | County estimate |
| Benton | 48.0 | 2.8 | Soft | County estimate |
| DeRidder | 24.0 | 1.4 | Soft | County estimate |
| Broussard | 159.0 | 9.3 | Hard | Utility-reported |
| Bogalusa | 13.9 | 0.8 | Soft | County estimate |
| Plaquemine | 140.0 | 8.2 | Hard | County estimate |
| Baker | 55.1 | 3.2 | Soft | County estimate |
| Walker | 26.0 | 1.5 | Soft | County estimate |
| St. Francisville | 140.0 | 8.2 | Hard | County estimate |
| Ventress | 136.0 | 8.0 | Hard | County estimate |
| Livingston | 26.0 | 1.5 | Soft | County estimate |
| Fort Polk | 14.5 | 0.8 | Soft | County estimate |
| Barksdale Afb | 48.0 | 2.8 | Soft | County estimate |
| Winnfield | 22.0 | 1.3 | Soft | County estimate |
| Rayne | 72.0 | 4.2 | Moderately hard | County estimate |
| Deville | 26.0 | 1.5 | Soft | County estimate |
| Kinder | 20.0 | 1.2 | Soft | County estimate |
| Slidell | 42.0 | 2.5 | Soft | County estimate |
| St. Francisville | 140.0 | 8.2 | Hard | County estimate |
| St. Martinville | 97.4 | 5.7 | Moderately hard | County estimate |
| Youngsville | 147.0 | 8.6 | Hard | Utility-reported |
| Westlake | 120.5 | 7.0 | Hard | County estimate |
| Jennings | 52.3 | 3.1 | Soft | County estimate |
| Donaldsonville | 66.1 | 3.9 | Moderately hard | County estimate |
| Welsh | 52.3 | 3.1 | Soft | County estimate |
| Leonville | 72.0 | 4.2 | Moderately hard | County estimate |
| Convent | 62.0 | 3.6 | Moderately hard | County estimate |
| St. James | 62.0 | 3.6 | Moderately hard | County estimate |
| Gilbert | 62.5 | 3.6 | Moderately hard | County estimate |
| Breaux Bridge | 97.4 | 5.7 | Moderately hard | County estimate |
| Angie | 13.9 | 0.8 | Soft | County estimate |
| Sunset | 72.0 | 4.2 | Moderately hard | County estimate |
| New Iberia | 136.0 | 8.0 | Hard | County estimate |
| Natchez | 32.3 | 1.9 | Soft | County estimate |
| Marksville | 98.0 | 5.7 | Moderately hard | County estimate |
| Greensburg | 5.7 | 0.3 | Soft | County estimate |
| Jena | 24.0 | 1.4 | Soft | County estimate |
| Crowville | 62.5 | 3.6 | Moderately hard | County estimate |
| Springhill | 25.0 | 1.5 | Soft | County estimate |
| Rosepine | 14.5 | 0.8 | Soft | County estimate |
| Franklinton | 13.9 | 0.8 | Soft | County estimate |
| Mansura | 98.0 | 5.7 | Moderately hard | County estimate |
| Harrisonburg | 39.2 | 2.3 | Soft | County estimate |
| Patterson | 125.0 | 7.3 | Hard | County estimate |
| Ponchatoula | 27.0 | 1.6 | Soft | County estimate |
| Basile | 72.0 | 4.2 | Moderately hard | County estimate |
| Columbia | 28.0 | 1.6 | Soft | County estimate |
| Oak Grove | 62.0 | 3.6 | Moderately hard | County estimate |
| Jonesville | 39.2 | 2.3 | Soft | County estimate |
| St. Gabriel | 140.0 | 8.2 | Hard | County estimate |
| Oakdale | 20.0 | 1.2 | Soft | County estimate |
| Albany | 26.0 | 1.5 | Soft | County estimate |
| Port Barre | 72.0 | 4.2 | Moderately hard | County estimate |
| Pollock | 23.6 | 1.4 | Soft | County estimate |
| Singer | 24.0 | 1.4 | Soft | County estimate |
| Folsom | 42.0 | 2.5 | Soft | County estimate |
| Lawtell | 72.0 | 4.2 | Moderately hard | County estimate |
| Berwick | 125.0 | 7.3 | Hard | County estimate |
| Lake Providence | 82.0 | 4.8 | Moderately hard | County estimate |
| Oberlin | 20.0 | 1.2 | Soft | County estimate |
| Boyce | 26.0 | 1.5 | Soft | County estimate |
| Ethel | 14.1 | 0.8 | Soft | County estimate |
| Jeanerette | 136.0 | 8.0 | Hard | County estimate |
| Coushatta | 63.5 | 3.7 | Moderately hard | County estimate |
| Grand Coteau | 72.0 | 4.2 | Moderately hard | County estimate |
| Farmerville | 21.4 | 1.3 | Soft | County estimate |
| Egan | 72.0 | 4.2 | Moderately hard | County estimate |
| Monterey | 80.0 | 4.7 | Moderately hard | County estimate |
| Greenwood | 55.4 | 3.2 | Soft | County estimate |
| Choudrant | 20.0 | 1.2 | Soft | County estimate |
| Grambling | 20.0 | 1.2 | Soft | County estimate |
| Woodworth | 26.0 | 1.5 | Soft | County estimate |
| Dequincy | 120.5 | 7.0 | Hard | County estimate |
| Lutcher | 62.0 | 3.6 | Moderately hard | County estimate |
| Kaplan | 132.0 | 7.7 | Hard | County estimate |
| Bunkie | 98.0 | 5.7 | Moderately hard | County estimate |
| Amite City | 27.0 | 1.6 | Soft | County estimate |
| Dubach | 20.0 | 1.2 | Soft | County estimate |
| Ferriday | 80.0 | 4.7 | Moderately hard | County estimate |
| Starks | 120.5 | 7.0 | Hard | County estimate |
| Vinton | 120.5 | 7.0 | Hard | County estimate |
| Arnaudville | 72.0 | 4.2 | Moderately hard | County estimate |
| Homer | 16.1 | 0.9 | Soft | County estimate |
| New Llano | 14.5 | 0.8 | Soft | County estimate |
| Effie | 98.0 | 5.7 | Moderately hard | County estimate |
| Edgard | 42.0 | 2.5 | Soft | County estimate |
| Abita Springs | 42.0 | 2.5 | Soft | County estimate |
| Kilbourne | 62.0 | 3.6 | Moderately hard | County estimate |
| Bell City | 778.0 | 45.5 | Very hard | County estimate |
| Iowa | 120.5 | 7.0 | Hard | County estimate |
| Lena | 26.0 | 1.5 | Soft | County estimate |
| Arcadia | 20.0 | 1.2 | Soft | County estimate |
| Grayson | 28.0 | 1.6 | Soft | County estimate |
| Mount Hermon | 13.9 | 0.8 | Soft | County estimate |
| Plaucheville | 98.0 | 5.7 | Moderately hard | County estimate |
| Forest Hill | 26.0 | 1.5 | Soft | County estimate |
| Reeves | 20.0 | 1.2 | Soft | County estimate |
| Pearl River | 42.0 | 2.5 | Soft | County estimate |
| Maringouin | 140.0 | 8.2 | Hard | County estimate |
| Hessmer | 98.0 | 5.7 | Moderately hard | County estimate |
| Amite | 27.0 | 1.6 | Soft | County estimate |
| Trout | 24.0 | 1.4 | Soft | County estimate |
| Elmer | 26.0 | 1.5 | Soft | County estimate |
| Hineston | 14.5 | 0.8 | Soft | County estimate |
| Cottonport | 98.0 | 5.7 | Moderately hard | County estimate |
| Gramercy | 62.0 | 3.6 | Moderately hard | County estimate |
| Erath | 132.0 | 7.7 | Hard | County estimate |
| Haynesville | 16.1 | 0.9 | Soft | County estimate |
| Lake Arthur | 52.3 | 3.1 | Soft | County estimate |
| Amelia | 125.0 | 7.3 | Hard | County estimate |
| Belmont | 36.0 | 2.1 | Soft | County estimate |
| Calhoun | 27.4 | 1.6 | Soft | County estimate |
| Delcambre | 136.0 | 8.0 | Hard | County estimate |
| Plain Dealing | 48.0 | 2.8 | Soft | County estimate |
| Sarepta | 25.0 | 1.5 | Soft | County estimate |
| Roseland | 27.0 | 1.6 | Soft | County estimate |
| Jackson | 14.1 | 0.8 | Soft | County estimate |
| Colfax | 23.6 | 1.4 | Soft | County estimate |
| Logansport | 50.0 | 2.9 | Soft | County estimate |
| White Castle | 140.0 | 8.2 | Hard | County estimate |
| Start | 59.0 | 3.5 | Soft | County estimate |
| Glenmora | 26.0 | 1.5 | Soft | County estimate |
| Livonia | 136.0 | 8.0 | Hard | County estimate |
| Prairieville | 66.1 | 3.9 | Moderately hard | County estimate |
| Clinton | 14.1 | 0.8 | Soft | County estimate |
| Ringgold | 20.0 | 1.2 | Soft | County estimate |
| Innis | 136.0 | 8.0 | Hard | County estimate |
| Pioneer | 62.0 | 3.6 | Moderately hard | County estimate |
| Bethany | 55.4 | 3.2 | Soft | County estimate |
| Clarks | 28.0 | 1.6 | Soft | County estimate |
| Evergreen | 98.0 | 5.7 | Moderately hard | County estimate |
| Kentwood | 27.0 | 1.6 | Soft | County estimate |
| Bernice | 21.4 | 1.3 | Soft | County estimate |
| Oil City | 55.4 | 3.2 | Soft | County estimate |
| Simmesport | 98.0 | 5.7 | Moderately hard | County estimate |
| Palmetto | 72.0 | 4.2 | Moderately hard | County estimate |
| Krotz Springs | 72.0 | 4.2 | Moderately hard | County estimate |
| Gueydan | 132.0 | 7.7 | Hard | County estimate |
| Milton | 84.1 | 4.9 | Moderately hard | County estimate |
| Slaughter | 14.1 | 0.8 | Soft | County estimate |
| Merryville | 24.0 | 1.4 | Soft | County estimate |
| Cameron | 778.0 | 45.5 | Very hard | County estimate |
| Shongaloo | 25.0 | 1.5 | Soft | County estimate |
| Georgetown | 23.6 | 1.4 | Soft | County estimate |
| Iota | 72.0 | 4.2 | Moderately hard | County estimate |
| Simsboro | 20.0 | 1.2 | Soft | County estimate |
| Campti | 32.3 | 1.9 | Soft | County estimate |
| Washington | 72.0 | 4.2 | Moderately hard | County estimate |
| Hornbeck | 14.5 | 0.8 | Soft | County estimate |
| Moreauville | 98.0 | 5.7 | Moderately hard | County estimate |
| Grant | 20.0 | 1.2 | Soft | County estimate |
| Olla | 24.0 | 1.4 | Soft | County estimate |
| Morrow | 72.0 | 4.2 | Moderately hard | County estimate |
| Turkey Creek | 24.0 | 1.4 | Soft | County estimate |
| Winnsboro | 62.5 | 3.6 | Moderately hard | County estimate |
| Forest | 62.0 | 3.6 | Moderately hard | County estimate |
| Cheneyville | 26.0 | 1.5 | Soft | County estimate |
| Cullen | 25.0 | 1.5 | Soft | County estimate |
| Collinston | 33.0 | 1.9 | Soft | County estimate |
| Cotton Valley | 25.0 | 1.5 | Soft | County estimate |
| Fordoche | 136.0 | 8.0 | Hard | County estimate |
| Summerfield | 16.1 | 0.9 | Soft | County estimate |
| Montgomery | 23.6 | 1.4 | Soft | County estimate |
| Melville | 72.0 | 4.2 | Moderately hard | County estimate |
| Dubberly | 25.0 | 1.5 | Soft | County estimate |
| Wisner | 62.5 | 3.6 | Moderately hard | County estimate |
| Gibsland | 20.0 | 1.2 | Soft | County estimate |
| Pelican | 50.0 | 2.9 | Soft | County estimate |
| Kelly | 28.0 | 1.6 | Soft | County estimate |
| Elton | 52.3 | 3.1 | Soft | County estimate |
| Transylvania | 82.0 | 4.8 | Moderately hard | County estimate |
| Newellton | 68.6 | 4.0 | Moderately hard | County estimate |
| Marion | 21.4 | 1.3 | Soft | County estimate |
| Mer Rouge | 33.0 | 1.9 | Soft | County estimate |
| Keithville | 55.4 | 3.2 | Soft | County estimate |
| Simpson | 14.5 | 0.8 | Soft | County estimate |
| Echo | 26.0 | 1.5 | Soft | County estimate |
| Elizabeth | 20.0 | 1.2 | Soft | County estimate |
| Morganza | 136.0 | 8.0 | Hard | County estimate |
| Doyline | 25.0 | 1.5 | Soft | County estimate |
| Mooringsport | 55.4 | 3.2 | Soft | County estimate |
| Grosse Tete | 140.0 | 8.2 | Hard | County estimate |
| Sicily Island | 39.2 | 2.3 | Soft | County estimate |
| Mangham | 59.0 | 3.5 | Soft | County estimate |
| Wilson | 14.1 | 0.8 | Soft | County estimate |
| Estherwood | 72.0 | 4.2 | Moderately hard | County estimate |
| Mermentau | 72.0 | 4.2 | Moderately hard | County estimate |
| Morse | 72.0 | 4.2 | Moderately hard | County estimate |
| Tullos | 22.0 | 1.3 | Soft | County estimate |
| Urania | 24.0 | 1.4 | Soft | County estimate |
| Chatham | 13.2 | 0.8 | Soft | County estimate |
| Tickfaw | 27.0 | 1.6 | Soft | County estimate |
| Tangipahoa | 27.0 | 1.6 | Soft | County estimate |
| Epps | 62.0 | 3.6 | Moderately hard | County estimate |
| Rosedale | 140.0 | 8.2 | Hard | County estimate |
| Calvin | 22.0 | 1.3 | Soft | County estimate |
| Hall Summit | 63.5 | 3.7 | Moderately hard | County estimate |
| Enterprise | 39.2 | 2.3 | Soft | County estimate |
| Goldonna | 22.0 | 1.3 | Soft | County estimate |
| Many | 36.0 | 2.1 | Soft | County estimate |
| Powhatan | 32.3 | 1.9 | Soft | County estimate |
| Garyville | 42.0 | 2.5 | Soft | County estimate |
| Athens | 16.1 | 0.9 | Soft | County estimate |
| Bonita | 33.0 | 1.9 | Soft | County estimate |
| Franklin | 125.0 | 7.3 | Hard | County estimate |
| Lisbon | 16.1 | 0.9 | Soft | County estimate |
| Fenton | 52.3 | 3.1 | Soft | County estimate |
| Bienville | 20.0 | 1.2 | Soft | County estimate |
| Norwood | 14.1 | 0.8 | Soft | County estimate |
| Lillie | 21.4 | 1.3 | Soft | County estimate |
| Downsville | 21.4 | 1.3 | Soft | County estimate |
| Independence | 27.0 | 1.6 | Soft | County estimate |
| Sibley | 25.0 | 1.5 | Soft | County estimate |
| Haughton | 48.0 | 2.8 | Soft | County estimate |
| Saint Amant | 66.1 | 3.9 | Moderately hard | County estimate |
| Atlanta | 22.0 | 1.3 | Soft | County estimate |
| Castor | 20.0 | 1.2 | Soft | County estimate |
| Converse | 36.0 | 2.1 | Soft | County estimate |
| Dry Prong | 23.6 | 1.4 | Soft | County estimate |
| Heflin | 25.0 | 1.5 | Soft | County estimate |
| Pleasant Hill | 36.0 | 2.1 | Soft | County estimate |
| Provencal | 32.3 | 1.9 | Soft | County estimate |
| Quitman | 13.2 | 0.8 | Soft | County estimate |
Above 120 mg/L (7 gpg), scale is usually worth treating — see our water softener guide, or size a system with the hardness calculator & converter.
The Geology Behind Louisiana's Water Hardness
Louisiana sits in the Southeastern Coastal Plain and Piedmont region.
Much of the Southeast draws its water from sandy Coastal Plain aquifers and from rivers draining crystalline Piedmont rock - neither contributes much dissolved calcium or magnesium. As a result the USGS maps most of the region as soft to moderately hard. Hardness climbs where supplies tap deeper limestone units near the Gulf and Atlantic coasts.
Louisiana Water Hardness FAQ
Does Louisiana have hard water?
Yes — across Louisiana's measured cities, typical tap water is hard. The median is 134.7 mg/L (7.9 gpg) — hard on the USGS scale, where anything above 120 mg/L (7 gpg) counts as hard. 13 of Louisiana's 25 measured cities fall in the hard or very hard bands (52%), so check your own city rather than the state average.
How hard is tap water in Louisiana?
Across the 25 Louisiana cities with measured values in our index, the median hardness is 134.7 mg/L (7.9 gpg) — hard on the USGS scale. Individual cities range from 3.9 to 211.0 mg/L, so check your own city rather than assuming the state number.
Which city in Louisiana has the hardest water?
Carlyss has the hardest measured tap water in our Louisiana index at 211.0 mg/L (12.3 gpg) — very hard on the USGS scale. Rankings use measured utility values only; labeled county estimates and values under active dispute are excluded.
Do I need a water softener in Louisiana?
13 of Louisiana's 25 measured cities (52%) fall in the hard or very hard bands — above 120 mg/L (7 gpg), the level where most water treatment professionals suggest considering an ion-exchange softener. Hardness varies utility to utility, so look up your own city's value before sizing equipment.
How do I find my city's exact water hardness?
Enter your ZIP code in our free lookup at tapwaterdata.com/zip to see the value we hold for your Louisiana city from utility-reported water quality data, check your water utility's annual Consumer Confidence Report (CCR), or use a home test-strip kit.
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