US watershed and drinking water source - where your tap water comes from

Well Water in Louisiana

Contaminant risks, testing requirements, and treatment recommendations for private well owners in Louisiana.

Louisiana Geology and Groundwater

Louisiana sits on Gulf Coastal Plain alluvial sediments. This geology directly determines what contaminants are likely in private well water. Based on this geology, Louisiana well owners face elevated risk for iron and manganese from dissolved minerals. Moderate risk exists for PFAS.

Contaminant Risk Profile

ContaminantRisk LevelWhy
ArsenicLow riskGenerally low in this region's geology.
NitrateLow riskGenerally low outside of agricultural areas.
RadonLow riskNot a primary concern in most of this state.
PFASModerate riskSome known contamination sites exist. Check EWG's PFAS map for your area.
Iron/ManganeseElevated riskVery common in this state's groundwater. Causes staining but is not a health risk.

How Louisiana Compares: Municipal Water Data

CheckMyTap tracks water quality for 15 cities in Louisiana. While these numbers reflect municipal water (not private wells), they indicate the baseline mineral content of Louisiana's water sources. Private wells often draw from the same aquifers but with less treatment.

MetricLouisiana AverageNational Average
Hardness81 PPM (moderately hard)170 PPM
Hardness range40 - 180 PPM25 - 400+ PPM
Lead (avg municipal)2.8 ppb3.2 ppb
Nitrate (avg municipal)0.6 mg/L1.1 mg/L
Cities with PFAS detected9 of 15~45% nationally
Cities exceeding PFAS MCL (4 ppt)9

Hardest water in Louisiana: Thibodaux (180 PPM), Lafayette South (100 PPM), Baton Rouge (86 PPM), Kenner (85 PPM), Marrero (85 PPM).

Softest water: Monroe (40 PPM), Slidell (60 PPM), New Orleans Uptown (60 PPM).

Testing Requirements in Louisiana

Louisiana does not have a statewide mandatory testing requirement for existing private wells. Regardless of state requirements, the EPA recommends testing annually for:

  • Every year: Total coliform bacteria, E. coli, nitrate, pH, and total dissolved solids
  • At least once: Arsenic, lead, copper, fluoride, and any contaminant identified as a local risk
  • Recommended for Louisiana: PFAS panel, especially if near military bases or industrial sites
  • After events: Retest after flooding, well repairs, nearby construction, or any change in taste/color/odor

Recommended Treatment for Louisiana Wells

Based on Louisiana's geology and common contaminant risks, these treatment systems address the most likely issues:

Iron/Manganese Filter

Whole-house oxidation filter removes iron staining and manganese discoloration

Learn more
UV Disinfection

Kills bacteria and viruses without chemicals. Recommended for all well water systems

Already have your lab results? Use our free well water interpreter to find out what your numbers mean. Interpret your well water lab report

Frequently Asked Questions

Is well water in Louisiana safe to drink?

Well water quality in Louisiana varies significantly by location and geology. Louisiana sits on Gulf Coastal Plain alluvial sediments. Key concerns include iron and manganese from dissolved minerals. The only way to know your specific water quality is to test it. Use our free interpreter to understand your results.

How often should I test my well water in Louisiana?

The EPA recommends testing annually for bacteria (total coliform, E. coli), nitrate, total dissolved solids, and pH. Test more frequently if you notice changes in taste, color, or odor, or after flooding, nearby construction, or well repairs.

Does Louisiana require well water testing?

Louisiana does not have a statewide mandatory testing requirement for existing private wells. However, the EPA strongly recommends annual testing regardless of state requirements. Your county health department may have additional local requirements.

What is the average water hardness in Louisiana?

Municipal water in Louisiana averages 81 PPM across 15 cities tracked by CheckMyTap, ranging from 40 to 180 PPM. Private well water typically runs 20-50% harder than city water because groundwater has more contact time with mineral formations. Many Louisiana well owners have manageable hardness levels, though local variation is significant. Check your city's data.

View All 15 Louisiana City Reports