Barium in Connecticut Drinking Water
By Alexander Snyder, Founder & Water Quality Data Lead
The U.S. EPA sets the legal limit (MCL) for Barium at 2 mg/L, and the health-based safe level set by the Environmental Working Group (EWG) is 0.7 ppm. A level that is legal is not always the level science considers fully protective.
Barium has been detected in 123 Connecticut ZIP codes, above a limit or health guideline in 1. Here is what you need to know about barium in your drinking water and how it may affect your household.
What Is Barium?
Barium is a naturally occurring alkaline earth metal that dissolves into groundwater from the weathering of barium-bearing minerals such as barite and witherite. It is more common in areas with limestone and dolomite geology. The EPA maximum contaminant level is 2 milligrams per liter. Chronic exposure to elevated barium levels causes increased blood pressure, and high acute doses can cause cardiac arrhythmia.
Is Barium in Your Water?
Enter your Connecticut ZIP code to find out if barium is in your local water — and see personalized health risks for your household.
Check Your ZIP CodeHealth Effects of Barium
Increase in blood pressure
Safety Guidelines
Health Guideline
0.7 ppm
Source: EWG
Legal Limit (MCL)
2 mg/L
EPA Maximum Contaminant Level
Barium's health-based safe level is set below the federal legal limit.
| Standard | Level | Source |
|---|---|---|
| EPA Legal Limit (MCL) | 2 mg/L | EPA |
| Health Guideline | 0.7 ppm | EWG |
Where Does Barium Come From?
Discharge of drilling wastes; discharge from metal refineries; erosion of natural deposits
How to Reduce Barium in Your Water
- 1Install a reverse osmosis system certified to NSF/ANSI Standard 58 for barium reduction, which removes approximately 90 to 95% of dissolved barium.
- 2Use a cation exchange water softener, which effectively removes barium because it behaves chemically like calcium and is exchanged onto the resin during normal softening.
- 3For residential use, reverse osmosis and ion exchange are the most practical and well-documented options for barium reduction.
- 4Test your water before and after treatment to verify barium reduction, and maintain your system according to the manufacturer's schedule.
Who Is Most Vulnerable to Barium?
The safe level of barium varies significantly depending on who is drinking the water. CheckYourTap calculates adjusted safe levels for each member of your household:
A contaminant level that is safe for an adult may exceed guidelines for an infant by 4-8x or more. Check your ZIP code to see personalized results.
Concerned about Barium in your water?
Schedule to get your water tested for barium and more — a Valiant water specialist will review your results and arrange testing for your home.
Frequently Asked Questions
Is Barium in my tap water?▾
What level of Barium is safe?▾
How do I remove Barium from my water?▾
Related Contaminants
Check Water Quality by ZIP Code
Sources
The legal limits and health guidelines for Barium on this page come from the following public authorities:
About This Report
This water quality report is compiled from public records filed with the U.S. Environmental Protection Agency, state health departments, and the U.S. Geological Survey. Contaminant levels are evaluated against EPA federal standards and health-based guidelines from leading environmental and public health organizations. CheckYourTap is a service of Valiant Energy Solutions, a Connecticut water quality and energy services company established in 1930.
This report is general information, not medical advice or a substitute for certified laboratory testing. Talk to your pediatrician or physician about specific health concerns.
Reviewed by the CheckYourTap editorial team. Last updated July 2026