State Well Water Guide
Louisiana Private Well Water Guide
About 18% of Louisianans rely on private wells, primarily in rural north Louisiana, the Florida Parishes (east of the Mississippi River), and some coastal communities. Louisiana's geology presents a complex groundwater picture: the Chicot aquifer system in southwest Louisiana has naturally elevated arsenic; the Carrizo-Wilcox aquifer in north Louisiana provides good quality water with occasional iron and manganese; and coastal plain aquifers face saltwater intrusion risk in the south. The state's industrial corridor (Cancer Alley) along the Mississippi River creates significant PFAS and industrial chemical concerns for some well users. LDHH provides well construction oversight.
Testing Guidance
LDHH recommends annual testing for coliform bacteria and nitrates. Southwest Louisiana Chicot aquifer well owners should test for arsenic and radium. North Louisiana well owners should test for iron, manganese, and bacteria. Well owners in the Florida Parishes near industrial facilities and in the Mississippi River corridor should test for VOCs and PFAS. Coastal well owners should monitor for saltwater intrusion.
What to Test For in Louisiana
Total coliform bacteria and E. coli — annual minimum
Arsenic — southwest Louisiana Chicot aquifer wells
Radium — some Louisiana aquifer systems have elevated naturally occurring radioactivity
Iron and manganese — statewide, particularly in sedimentary aquifer systems
PFAS and VOCs — Industrial Corridor (River Parishes), near Barksdale AFB and England Airpark
Chloride and sodium — coastal and deltaic areas at risk of saltwater intrusion
Nitrates — agricultural north Louisiana and areas with dense septic
Common Contamination Risks in Louisiana
Arsenic from the Chicot aquifer — the Chicot aquifer system in southwest Louisiana (Calcasieu, Beauregard, Allen, Jefferson Davis parishes) has documented naturally elevated arsenic above the 10 ppb MCL
Industrial chemical contamination — the Mississippi River Industrial Corridor has numerous facilities releasing VOCs, PFAS, and other chemicals that can affect groundwater
Saltwater intrusion — Louisiana's subsiding coastal plain makes saltwater intrusion an ongoing threat to freshwater aquifers in southern parishes
Iron and manganese from sedimentary aquifers — naturally elevated throughout Louisiana's predominantly sedimentary geology
PFAS from military and industrial sources — Barksdale AFB, England Airpark, and numerous industrial facilities
Contaminant Guides Relevant to LA Wells
PFAS
Synthetic Chemicals
EPA limit: 4 ppt
Lead
Heavy Metals
EPA limit: 15 ppb (action level)
Nitrates
Agricultural Chemicals
EPA limit: 10 mg/L
DBPs
Disinfection Byproducts
EPA limit: 80 µg/L (TTHMs) / 60 µg/L (HAA5)
Arsenic
Heavy Metals
EPA limit: 10 ppb
Hard Water
Minerals
EPA limit: No federal limit
Chlorine
Disinfection Chemicals
EPA limit: 4 mg/L (MRDL)
Microplastics
Emerging Contaminants
EPA limit: No federal limit
Bacteria
Microbial Contamination
EPA limit: Zero E. coli / < 1 coliform per 100 mL
Fluoride
Minerals
EPA limit: 4 mg/L (MCL) / 2 mg/L (Secondary MCL)
Chromium-6
Heavy Metals
EPA limit: 100 ppb (total chromium)
Copper
Heavy Metals
EPA limit: 1.3 mg/L (action level)
Radon
Radioactive Contaminants
EPA limit: No finalized MCL
Iron & Manganese
Minerals
EPA limit: 0.3 mg/L iron / 0.05 mg/L manganese (aesthetic SMCLs)
Atrazine
Agricultural Chemicals
EPA limit: 3 ppb (0.003 mg/L)
Uranium
Radioactive Contaminants
EPA limit: 30 µg/L (30 ppb)
Perchlorate
Industrial Chemicals
EPA limit: 0.056 mg/L (56 ppb)
VOCs
Industrial Chemicals
EPA limit: Varies by compound: benzene 5 ppb; TCE 5 ppb; PCE 5 ppb; vinyl chloride 2 ppb
Radium
Radioactive Contaminants
EPA limit: 5 pCi/L (combined Ra-226 + Ra-228)
Crypto & Giardia
Microbial Contamination
EPA limit: Zero (treatment technique standard)
Hydrogen Sulfide
Naturally Occurring Compounds
EPA limit: No MCL; Secondary MCL (aesthetic) of 0.05 mg/L
Selenium
Minerals
EPA limit: 50 ppb (0.05 mg/L)
Cadmium
Heavy Metals
EPA limit: 5 ppb (0.005 mg/L)
Mercury
Heavy Metals
EPA limit: 2 ppb (0.002 mg/L)
Barium
Heavy Metals
EPA limit: 2 mg/L
Find a Certified Lab in Louisiana
Use the Louisiana state-certified laboratory program to find accredited labs for private well testing. Always verify current certification before submitting samples.
LA Certified Lab Directory ↗Louisiana Well Water FAQs
Related Pages
Data Sources & Provenance
All data on this page is sourced from official U.S. government or public datasets.
Quick Reference
State program
LA Certified Labs ↗EPA guidance
EPA Private Wells Program ↗State lab directory
LA Certified Labs ↗Minimum Annual Tests
Plus state-specific contaminants listed above
Other State Guides