Barium is a silvery-white metal, which does not occur in nature in its elemental form but in a number of compounds. The two most common compounds include barium sulfate and barium carbonates, which are often found in underground deposits. Barium compounds are also used in paints, bricks, ceramics, glass, rubber, spark plugs, fireworks, x-ray diagnostic work, and as drilling mud weighing agents used by the oil and gas industry. The primary source of barium in our drinking water is due to groundwater erosion of geological formations containing barium compounds; however, barium can also be introduced into groundwater due to any of the above-mentioned industrial processes. When barium levels exceed 1 mg/L, this may indicate the water is being polluted by an industrial source.
How it is regulated?
In 1991, the Environmental Protection Agency (EPA) established the Maximum Contaminant Level Goal (MCLG) at a level of 2 mg/L. The MCLG is a non-enforceable level based solely on possible health risks and exposure, which means, the EPA says that at 2 mg/L Barium would not cause any potential health problems. Once the MCLG is established, the EPA then sets the MCL, which is set as close as possible to the MCLG as feasible considering technology and resources. In the case of barium, the MCL was set at 2 mg/L given present technology and resources available for public water systems to reasonably remove the contaminant should it occur in the drinking water systems. The regulation went into effect in 1992, so public water supplies were required to monitor for barium and report any presence that exceeded the MCL. How will it affect health?
Acute health effects are those that occur after a short time of exposure to a high level. Acute effects for barium exposure include gastrointestinal disturbances and weakness in the muscles. Chronic health effects are those that occur after along period of exposure to a small amount. Small amounts of barium over long period of time may cause a person to experience breathing difficulties, increase blood pressure, heart rhythm changes, stomach irritation, muscle weakness, changes in nerve reflexes, swelling of brain or liver, and kidney or heart damage.
How is it tested?
Since barium is a health-based contaminant you should have the water analyze using a laboratory. Laboratories analyzing drinking water samples can utilize various methods including EPA method 200.7 and 200.8 which utilize an Inductively Coupled Plasma (ICP) or the Standards Method 3113B which uses Graphite Furnace.
Water Treatment Options
Since barium is chemically similar to calcium, it can easily be removed by ion exchange( more commonly called “softening”). Ion exchange, specifically cation exchange, basically exchanges the sodium ion for barium, calcium or other cations.
Reverse Osmosis and distillations are also viable ways to remove barium, but have limitations in the amount of water that can be produced. Lime softening is a treatment technique utilized by municipalities, which partially removes hardness minerals, including barium, by precipitation followed by filtration.