Water Education - Contaminants Facts

Drinking Water Contaminants- Barium

This is a factsheet about a chemical that may be found in some public or private drinking water supplies. It may cause health problems if found in amounts greater than the health standard set by the United States Environmental Protection Agency (EPA).

What is Barium and how is it used?

Barium is a lustrous, machinable metal that exists in nature only in ores containing mixtures of elements. It is used in making a wide variety of electronic components, in metal alloys, bleaches, dyes, fireworks, ceramics, and glass. In particular, it is used in well drilling operations where it is directly released into the ground.

Why is Barium being regulated?

In 1974, Congress passed the Safe Drinking Water Act. This law requires EPA to determine safe levels of chemicals in drinking water that do or may cause health problems. These non-enforceable levels, based solely on possible health risks and exposure, are called Maximum Contaminant Level Goals.

The MCLG for barium has been set at 2 parts per million (ppm) because EPA believes this level of protection would not cause any of the potential health problems described below.

Based on this MCLG, EPA has set an enforceable standard called a Maximum Contaminant Level (MCL). MCLs are set as close to the MCLGs as possible, considering the ability of public water systems to detect and remove contaminants using suitable treatment technologies.

The MCL has also been set at 2 ppm because EPA believes, given present technology and resources, this is the lowest level to which water systems can reasonably be required to remove this contaminant should it occur in drinking water.

These drinking water standards and the regulations for ensuring these standards are met, are called National Primary Drinking Water Regulations. All public water supplies must abide by these regulations.

What are the health effects?

Short-term: EPA has found barium to potentially cause the following health effects when people are exposed to it at levels above the MCL for relatively short periods of time: gastrointestinal disturbances and muscular weakness.

Long-term: Barium has the potential to cause the following effects from a lifetime exposure at levels above the MCL: high blood pressure.

How much Barium is produced and released to the environment?

The most common ores are found in AK, AR, CA, GA, KY, MO, NV, and TN. Barite was produced at 38 mines in these states in 1973, with Nevada supplying 50% of the tonnage. Barium is released to water and soil in the discharge and disposal of drilling wastes, from the smelting of copper, and the manufacture of motor vehicle parts and accessories.

From 1987 to 1993, according to the Toxics Release Inventory barium compound releases to land and water totaled over 57 million lbs. These releases were primarily from copper smelting industries. The largest releases occurred in Arizona and Utah. The largest direct releases to water occurred in Texas.

What happens to Barium when it is released to the environment?

In water, the more toxic soluble barium salts are likely to be converted to insoluble salts which precipitate. Barium does not bind to most soils and may migrate to groundwater. It has a low tendency to accumulate in aquatic life.

How will Barium be detected in and removed from my drinking water?

The regulation for barium became effective in 1992. Between 1993 and 1995, EPA required your water supplier to collect water samples once and analyze them to find out if barium is present above 2 ppm. If it is present above this level, the system must continue to monitor this contaminant.

If contaminant levels are found to be consistently above the MCL, your water supplier must take steps to reduce the amount of barium so that it is consistently below that level. The following treatment methods have been approved by EPA for removing barium: Ion Exchange, Reverse Osmosis, Lime Softening, Electrodialysis.

How will I know if Barium is in my drinking water?

If the levels of barium exceed the MCL, the system must notify the public via newspapers, radio, TV, and other means. Additional actions, such as providing alternative drinking water supplies, may be required to prevent serious risks to public health.

This is a factsheet about a chemical that may be found in some public or private drinking water supplies. It may cause health problems if found in amounts greater than the health standard set by the United States Environmental Protection Agency (EPA).

Drinking Water Standards:

  • MCLG: 2 ppm
  • MCL: 2 ppm

Barium Releases to Water and Land: 1987 to 1993 (in pounds)

Top Ten States *
Major Industries*
Copper smelting1,50031,958,310
Car parts, accessories1,7439,456,667
Industrial organics132,5114,106,827
Inorganic pigments5,2613,672,451
Gray, ductile iron01,556,681
Steelworks, furnaces256,582679,999
Paper mills64,770527,330

* Water/Land totals only include facilities with releases greater than a certain amount - usually 1000 to 10,000 lbs.

As part of the Drinking Water and Health pages, this fact sheet is part of a larger U.S. EPA publication:
EPA National Primary Drinking Water Regulations
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