State Well Water Guide
Florida Private Well Water Guide
Florida has over 1 million private wells, with use concentrated in rural areas of North and Central Florida. Florida's unique geology — primarily porous karst limestone (the Floridan Aquifer System) — creates both the state's water abundance and its contamination vulnerabilities. Key concerns include naturally occurring radium, uranium, and radon from phosphate-rich limestone, nitrate and bacterial contamination from septic systems and agricultural runoff, and legacy contamination from the phosphate mining industry in the central state.
Testing Guidance
The Florida Department of Health recommends annual testing for bacteria and nitrates. Given Florida's karst geology (limestone with sinkholes and direct conduits to the aquifer), bacterial testing after heavy rainfall is especially important. Annual testing for radium and uranium is recommended for wells in the phosphate mining belt (Polk, Hillsborough, Manatee, Hardee, DeSoto counties). PFAS testing is advised near military bases and airports. All new wells should receive a comprehensive baseline test.
What to Test For in Florida
Total coliform bacteria and E. coli — annual minimum; re-test after flooding
Nitrates — annual for wells near agricultural land or septic systems
Radium-226 and Radium-228 — Polk, Hillsborough, Manatee, Hardee counties (phosphate region)
Uranium — phosphate mining belt in Central Florida
Radon — Florida has some of the highest residential radon from phosphate geology; water can be a secondary source
Arsenic — some areas of North and Central Florida
Iron and manganese — common throughout Florida; aesthetic issue but affects water quality
Hydrogen sulfide — common in Florida's sulfur-containing aquifer formations
PFAS — near Tyndall, Eglin, MacDill, Patrick, and other Florida military installations
Total dissolved solids and hardness — baseline; water in South Florida is typically very hard
Common Contamination Risks in Florida
Radium and uranium from phosphate geology — Central Florida's phosphate deposits contain naturally occurring radioactive materials (NORM) that leach into the Floridan Aquifer
Karst vulnerability — Florida's limestone geology means surface contaminants can reach groundwater quickly through sinkholes and fractures; this makes bacterial contamination after flooding a significant risk
Nitrate contamination from septic systems — Florida's high water table and sandy soils in many areas mean septic system effluent can reach wells, particularly those less than 75 feet deep
Iron and hydrogen sulfide — the sulfate-reducing environment of Florida's aquifers produces hydrogen sulfide odor and dissolved iron in many wells, particularly in the Hawthorn Formation
Agricultural chemical runoff — cattle operations in the Kissimmee Valley, citrus in the Ridge, and vegetable farming in the south contribute to nitrate and pesticide contamination
PFAS from military installations — multiple Florida bases (Tyndall, Eglin, Patrick, MacDill) used AFFF firefighting foam with documented impacts on surrounding groundwater
Saltwater intrusion — South Florida's overpumped aquifers face serious saltwater intrusion; some areas near the coast have groundwater with TDS well above drinking water standards
Contaminant Guides Relevant to FL 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 Florida
Use the Florida state-certified laboratory program to find accredited labs for private well testing. Always verify current certification before submitting samples.
FL Certified Lab Directory ↗Florida 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
FL Certified Labs ↗EPA guidance
EPA Private Wells Program ↗State lab directory
FL Certified Labs ↗Minimum Annual Tests
Plus state-specific contaminants listed above
Other State Guides