Private Well Water Testing in Louisiana
County-by-county USGS area-risk estimates for private wells across Louisiana — arsenic exceedance probability and private-well population — plus how to test your own well at a Louisiana-certified laboratory.
Louisiana private-well risk summary
Counties covered
63
Louisiana counties with modeled risk data.
People on private wells
area estimate460,713
estimated across covered Louisiana counties.
Average arsenic risk
area estimate2%
average modeled chance a well exceeds 10 µg/L arsenic across covered counties.
Louisiana counties
- St. Tammany Parish2% arsenic exceedance (area estimate)49,749 people on private wells
- Tangipahoa Parish2% arsenic exceedance (area estimate)38,030 people on private wells
- Vermilion Parish3% arsenic exceedance (area estimate)26,952 people on private wells
- Calcasieu Parish1% arsenic exceedance (area estimate)26,162 people on private wells
- Lafayette Parish2% arsenic exceedance (area estimate)23,194 people on private wells
- Caddo Parish2% arsenic exceedance (area estimate)21,919 people on private wells
- Livingston Parish2% arsenic exceedance (area estimate)21,633 people on private wells
- Washington Parish2% arsenic exceedance (area estimate)21,303 people on private wells
- Ascension Parish2% arsenic exceedance (area estimate)19,713 people on private wells
- Vernon Parish1% arsenic exceedance (area estimate)18,429 people on private wells
- Acadia Parish3% arsenic exceedance (area estimate)18,380 people on private wells
- Bossier Parish2% arsenic exceedance (area estimate)16,054 people on private wells
- Iberia Parish4% arsenic exceedance (area estimate)11,393 people on private wells
- Sabine Parish1% arsenic exceedance (area estimate)10,423 people on private wells
- Beauregard Parish1% arsenic exceedance (area estimate)9,459 people on private wells
- De Soto Parish2% arsenic exceedance (area estimate)8,628 people on private wells
- St. Landry Parish3% arsenic exceedance (area estimate)8,446 people on private wells
- Franklin Parish2% arsenic exceedance (area estimate)8,184 people on private wells
- Rapides Parish2% arsenic exceedance (area estimate)7,364 people on private wells
- Ouachita Parish2% arsenic exceedance (area estimate)6,741 people on private wells
- St. Martin Parish2% arsenic exceedance (area estimate)6,614 people on private wells
- St. Helena Parish2% arsenic exceedance (area estimate)6,606 people on private wells
- Richland Parish2% arsenic exceedance (area estimate)6,084 people on private wells
- Jefferson Davis Parish1% arsenic exceedance (area estimate)5,403 people on private wells
- Natchitoches Parish1% arsenic exceedance (area estimate)5,148 people on private wells
- Webster Parish1% arsenic exceedance (area estimate)4,778 people on private wells
- Evangeline Parish1% arsenic exceedance (area estimate)4,157 people on private wells
- Bienville Parish1% arsenic exceedance (area estimate)3,695 people on private wells
- Allen Parish1% arsenic exceedance (area estimate)3,431 people on private wells
- Claiborne Parish1% arsenic exceedance (area estimate)3,140 people on private wells
- Grant Parish3% arsenic exceedance (area estimate)3,110 people on private wells
- East Feliciana Parish3% arsenic exceedance (area estimate)2,834 people on private wells
- Red River Parish1% arsenic exceedance (area estimate)2,726 people on private wells
- Pointe Coupee Parish5% arsenic exceedance (area estimate)2,557 people on private wells
- East Baton Rouge Parish2% arsenic exceedance (area estimate)2,478 people on private wells
- Union Parish2% arsenic exceedance (area estimate)2,296 people on private wells
- Winn Parish2% arsenic exceedance (area estimate)2,284 people on private wells
- Morehouse Parish2% arsenic exceedance (area estimate)2,271 people on private wells
- Lincoln Parish1% arsenic exceedance (area estimate)2,148 people on private wells
- Iberville Parish2% arsenic exceedance (area estimate)2,044 people on private wells
- Avoyelles Parish2% arsenic exceedance (area estimate)1,992 people on private wells
- Jackson Parish2% arsenic exceedance (area estimate)1,917 people on private wells
- Orleans Parish2% arsenic exceedance (area estimate)1,340 people on private wells
- Cameron Parish3% arsenic exceedance (area estimate)1,177 people on private wells
- Catahoula Parish2% arsenic exceedance (area estimate)1,085 people on private wells
- St. Mary Parish4% arsenic exceedance (area estimate)910 people on private wells
- West Carroll Parish2% arsenic exceedance (area estimate)863 people on private wells
- Concordia Parish2% arsenic exceedance (area estimate)824 people on private wells
- LaSalle Parish3% arsenic exceedance (area estimate)670 people on private wells
- West Feliciana Parish4% arsenic exceedance (area estimate)592 people on private wells
- Caldwell Parish2% arsenic exceedance (area estimate)578 people on private wells
- St. John the Baptist Parish2% arsenic exceedance (area estimate)495 people on private wells
- West Baton Rouge Parish3% arsenic exceedance (area estimate)444 people on private wells
- St. Charles Parish2% arsenic exceedance (area estimate)344 people on private wells
- Madison Parish4% arsenic exceedance (area estimate)281 people on private wells
- Assumption Parish2% arsenic exceedance (area estimate)255 people on private wells
- Tensas Parish2% arsenic exceedance (area estimate)231 people on private wells
- Jefferson Parish4% arsenic exceedance (area estimate)211 people on private wells
- East Carroll Parish3% arsenic exceedance (area estimate)169 people on private wells
- Terrebonne Parish4% arsenic exceedance (area estimate)141 people on private wells
- St. James Parish3% arsenic exceedance (area estimate)106 people on private wells
- Plaquemines Parish5% arsenic exceedance (area estimate)100 people on private wells
- St. Bernard Parish5% arsenic exceedance (area estimate)28 people on private wells
Find a Louisiana-certified testing lab
Get your well tested at a Louisiana-certified laboratory. We list certification programs by state.
These figures are USGS area estimates: statistical groundwater models describing how likely elevated contaminant levels are across a county. They are not designed to predict the concentration in any single well. Only testing your own well reveals its water quality.
By TapWaterData Editorial
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