Fluoride in Well Water
Limits
EPA's enforceable limit is 4.0 mg/L, with a secondary level of 2.0 mg/L to protect children's teeth from staining. Health Canada's maximum is 1.5 mg/L.
Why test
Some groundwater has natural fluoride. If you have young children, ask your dentist or doctor about fluoride from your well before giving supplements.
Treatment
Reverse osmosis, distillation and activated alumina can reduce fluoride.
Sources
- EPA: National Primary Drinking Water Regulations
- EPA: Secondary drinking water standards
- Health Canada: Guidelines for Canadian Drinking Water Quality, summary table
Questions
Does well water have fluoride?
It can. Natural levels vary from none to above the limit, so only a test can tell.
Free well water safety checklist
15 family-friendly steps based on CDC and EPA guidance. Print it, keep it on the fridge, and know when to call a certified lab.
More guides
- Flood Protection for Well Owners: Before, During and After a FloodRaise and seal the wellhead, know your pump shutoff, then disinfect and test with a certified lab after any flood.
- PFAS “Forever Chemicals” in Private Wells: Why You Should TestFederal PFAS rules protect public water systems — not private wells. Here’s what “forever chemicals” mean for well owners and how to get tested.
- Nitrates in Well Water and Blue Baby Syndrome: Who Must TestNitrate in well water can cause blue baby syndrome in infants. Learn who is at risk, when to test, and how to find a certified lab.
- Arsenic in Private Well Water: The Invisible Risk UndergroundArsenic in groundwater is often naturally occurring and invisible. USGS research shows millions of private-well users may be above the EPA drinking-water standard.