This is a fact sheet 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 which 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 which do or
may cause health problems. These non-enforceable levels, based solely on
possible health risks and exposure, are called Maximum Contaminant Level
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
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 ground water. It has a low tendency to accumulate in
How will Barium be detected in and removed from my drinking
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
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 (parts per million)
Mcl: 2 ppm
Barium Releases to Water and Land, 1987 to 1993 (in pounds):
|Top Ten States*|
|Car parts, accessories
|Gray, ductile iron
* Water/Land totals only include facilities with releases greater
than a certain amount - usually 1000 to 10,000 lbs.
Note: This fact sheet is part of a larger publication
adapted from U.S. EPA publication: EPA National Primary Drinking Water