Sulfate in Well Water
Limits
EPA's secondary level is 250 mg/L. Health Canada's aesthetic objective is 500 mg/L.
Effects
High sulfate gives water a bitter taste and can cause a laxative effect, mostly in people not used to it and in infants. It can also feed the bacteria that make hydrogen sulfide.
Treatment
Reverse osmosis, distillation and anion exchange can reduce sulfate.
Sources
- EPA: Secondary drinking water standards
- Health Canada: Guidelines for Canadian Drinking Water Quality, summary table
- Penn State Extension: Hydrogen sulfide (rotten egg odor) in water wells
Questions
Should I use high-sulfate water for infant formula?
Ask your doctor. Using low-sulfate water is a common precaution.
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.