What Is Barium and Where Does It Come From?

Barium is an alkaline earth metal that occurs naturally in the environment. It is the 14th most abundant element in the Earth's crust and is found in several mineral forms, including barite (barium sulfate) and witherite (barium carbonate). Barium enters groundwater through the dissolution of these minerals, with concentrations varying based on local geology.

Natural barium concentrations in surface water typically range from 0.007 to 0.15 mg/L, while groundwater concentrations can be significantly higher, particularly in areas underlain by barium-bearing sedimentary formations. Concentrations exceeding 10 mg/L have been reported in some groundwater wells.

Industrial sources of barium include oil and gas drilling operations (barite is widely used as a weighting agent in drilling fluids), metal refining and alloy production, paint and pigment manufacturing, rubber and plastics production, and coal combustion. Barium compounds are also used in brick and tile manufacturing, glass production, and electronics.

Barium solubility in water is strongly influenced by the presence of sulfate. In waters with elevated sulfate, barium precipitates as insoluble barium sulfate, limiting dissolved barium concentrations. Conversely, low-sulfate groundwater may contain elevated dissolved barium levels.

Health Effects of Barium in Water

Barium affects the cardiovascular and nervous systems. Animal and human studies indicate that ingestion of soluble barium compounds at elevated concentrations can cause increases in blood pressure. This hypertensive effect is the basis for the EPA MCL of 2.0 mg/L.

Acute exposure to high barium concentrations (well above the MCL) can cause gastrointestinal effects including nausea, vomiting, and diarrhea, as well as cardiac arrhythmias, muscular weakness, and respiratory paralysis. Such acute exposures are rare in drinking water scenarios.

Chronic exposure to barium in drinking water at concentrations above the MCL has been associated with cardiovascular effects. Epidemiological studies have examined populations exposed to barium in drinking water and have reported associations with increased incidence of hypertension, though results are not fully consistent across all studies.

The EPA classifies barium as not classifiable regarding human carcinogenicity (Group D) based on inadequate evidence from both human and animal studies.

Regulatory Limits for Barium in Drinking Water

The EPA MCL of 2.0 mg/L was established based on the potential for hypertensive effects. The MCLG (Maximum Contaminant Level Goal) is also 2.0 mg/L, indicating the EPA considers the MCL to be achievable with available treatment technology without health risk at that level.

How to Test for Barium in Water

Barium cannot be detected by taste, odor, or appearance at concentrations near the MCL. Laboratory analysis using EPA Method 200.7 (ICP-OES) or EPA Method 200.8 (ICP-MS) is required for accurate quantification.

Samples should be collected in acid-washed polyethylene or polypropylene containers and preserved with nitric acid to a pH below 2 to prevent precipitation and adsorption to container walls. Analysis should be completed within six months of collection.

Treatment Methods for Barium Removal

Ion Exchange

Cation exchange water softeners effectively remove dissolved barium from water by exchanging barium ions for sodium ions on the resin. Ion exchange systems typically reduce barium to below 0.1 mg/L, well within the EPA MCL. This technology is widely used for both residential and commercial barium treatment and simultaneously removes hardness.

Reverse Osmosis

Reverse osmosis systems achieve barium rejection rates of 95-99%, making them highly effective for barium removal. RO is particularly well-suited for applications requiring simultaneous removal of barium and other dissolved contaminants. System design should consider the potential for barium sulfate scaling if sulfate is present in the feed water.

Lime Softening

Conventional lime softening at elevated pH can co-precipitate barium with calcium carbonate. The addition of sulfate to promote barium sulfate precipitation can enhance removal efficiency. This process is used in municipal water treatment plants treating groundwater with elevated barium.

Electrodialysis

Electrodialysis and electrodialysis reversal can remove barium along with other dissolved ions. These membrane processes are used in municipal and industrial applications as alternatives to RO, particularly where high water recovery is required.

Frequently Asked Questions

What are the health effects of barium in drinking water?

Short-term exposure to barium above the EPA MCL of 2.0 mg/L can cause gastrointestinal disturbance and muscular weakness. Long-term exposure has been associated with increased blood pressure and cardiovascular effects. The EPA set the MCL at 2.0 mg/L based on the potential for hypertensive effects from chronic exposure.

How does barium get into groundwater?

Barium enters groundwater primarily through the dissolution of naturally occurring barium-bearing minerals such as barite (barium sulfate) and witherite (barium carbonate). Concentrations are highest in areas with these geological formations. Industrial sources include oil and gas drilling operations (where barite is used in drilling mud), metal refining, and coal combustion.

Need to Remove Barium from Your Water?

ForeverPure provides commercial and industrial barium removal systems, including ion exchange softeners, reverse osmosis units, and integrated treatment solutions. Our engineering team designs systems based on your water analysis, flow requirements, and compliance targets.

Contact ForeverPure for a customized barium removal solution.