State Well Water Guide
Mississippi Private Well Water Guide
Approximately 30% of Mississippians rely on private wells, concentrated in rural agricultural areas across the Delta, Piney Woods, and Hills regions. Mississippi's shallow coastal plain aquifers are among the most vulnerable in the Southeast: the Mississippi Alluvial Aquifer (Delta) is heavily affected by agricultural contamination, while the Sand/Gravel aquifer system shows naturally elevated arsenic in parts of south Mississippi. MDEP regulates well construction; testing is voluntary for private well owners but strongly recommended given the agricultural contamination prevalence.
Testing Guidance
MSDH recommends annual testing for coliform bacteria and nitrates for all wells. Delta region well owners should test for nitrates, agricultural pesticides, and bacteria given the intense row crop agriculture. South Mississippi well owners should test for arsenic and iron/manganese from sand aquifer systems. All wells near agricultural operations should be tested after major flood events.
What to Test For in Mississippi
Total coliform bacteria and E. coli — annual minimum
Nitrates — Delta and agricultural areas statewide
Arsenic — south Mississippi sand and gravel aquifer wells
Iron and manganese — alluvial and coastal plain aquifer wells throughout the state
Agricultural pesticides and herbicides — Delta wells adjacent to row crop operations
PFAS — near Columbus AFB, Keesler AFB, and Camp Shelby
Total dissolved solids — general water quality baseline
Common Contamination Risks in Mississippi
Agricultural contamination in the Delta — the Mississippi Delta's intensive cotton, soybean, and corn agriculture creates one of the nation's most significant agricultural groundwater contamination zones
Iron and manganese from alluvial sediments — naturally elevated throughout the Mississippi Alluvial Plain and coastal plain aquifer systems
Arsenic in south Mississippi sand aquifers — naturally elevated arsenic has been found in Wilkinson, Adams, Jefferson, and surrounding south Mississippi counties
Bacterial contamination from agricultural and septic sources — high livestock densities and aging rural infrastructure
PFAS from military bases — Keesler AFB, Columbus AFB, and Camp Shelby have AFFF contamination histories
Contaminant Guides Relevant to MS 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
pH
Water Quality Indicators
EPA limit: 6.5–8.5 (secondary standard)
Find a Certified Lab in Mississippi
Use the Mississippi state-certified laboratory program to find accredited labs for private well testing. Always verify current certification before submitting samples.
MS Certified Lab Directory ↗Mississippi 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
MS Certified Labs ↗EPA guidance
EPA Private Wells Program ↗State lab directory
MS Certified Labs ↗Minimum Annual Tests
Plus state-specific contaminants listed above
Other State Guides