Barium in Tap Water
Barium is a metal that enters drinking water mostly through the natural erosion of mineral deposits, and sometimes from industrial discharge or oil-and-gas activity.
Natural erosion of barium-bearing rock into groundwater; also discharge from drilling operations and metal industries.
- 1Natural mineral deposits
- 2Drilling and industrial discharge
A result is read with its context
This contaminant is tracked through federal and state compliance monitoring. Private wells in mineral-rich areas should be tested directly. PurityMap does not yet publish a per-system measured value for Barium; this page is a reference explainer. To learn what is in your own water, check your utility’s Consumer Confidence Report (CCR) or use a certified home test.
- Above reference
- Evidence exceeds a reference level.
- Detected
- This substance was found in the monitoring record. Being present is not the same as being above a reference level, and this signal does not say which.
- Not detected
- Somebody looked and the laboratory reported nothing above its reporting limit. This is a result, and it is not the same as nobody looking.
- Not monitored
- No sampling for this substance has been reported for this system. Nothing is known either way, and an empty row is not a clean one.
1 city with a health-based violation
A violation is a past event with a status, from the federal compliance record (EPA SDWIS, since 2016). It does not describe the water today.
PurityMap does not yet publish a per-system measured value for barium. Check your utility’s Consumer Confidence Report, or use a certified home test.
What can carry a barium reduction claim
- Reverse osmosis
Semi-permeable membrane separation removing dissolved minerals, heavy metals, and persistent fluorinated chemicals down to 0.0001 microns.
- Ion exchange (softening)
Dedicated whole-house appliance exchanging hardness ions (calcium and magnesium) for sodium or potassium to prevent scale buildup.
- Electrodialysis
Boiling does not remove a dissolved chemical compound and can concentrate it. Many pitcher and refrigerator filters carry no verified claim for a compound like this at all.
A finding establishes the need, the need names the capability, the capability requires a verified certification. No product appears before that sequence completes. Filter Finder →
Frequently asked
Answers cite the same records as the page. How PurityMap analyzes water data
Barium is a metal that enters drinking water mostly through the natural erosion of mineral deposits, and sometimes from industrial discharge or oil-and-gas activity.
The enforceable federal limit is 2 mg/L (MCL). The health-based goal (MCLG) is 2 mg/L. PurityMap reads every measurement against its stated benchmark and never sets its own.
Natural mineral deposits, Drilling and industrial discharge.
Long-term exposure above the federal limit is associated in studies with increases in blood pressure. The enforceable limit is set with a margin below levels linked to those effects.
Treatment technologies commonly certified to reduce Barium include Reverse osmosis, Ion exchange (softening), Electrodialysis. Match the exact certified claim to your water before buying. Holding a format is not the same as holding the claim.
In the federal compliance record (EPA SDWIS, since 2016), 1 city in PurityMap's record across 1 state had a water system measure Barium above the legal limit, most recently in 2026, including South Elgin, IL. Each violation is a past event with a published status, not a description of the water today.