Chemicals (VOC) Water Treatment
What are VOCs?
Volatile Organic Chemicals (VOCs) are carbon-containing compounds that evaporate easily from water into air at normal air temperatures. (This is why the distinctive odor of gasoline and many solvents can easily be detected.) VOCs are contained in a wide variety of commercial, industrial and residential products including fuel oils, gasoline, solvents, cleaners and degreasers, paints, inks, dyes, refrigerants and pesticides. People are most commonly exposed to VOCs through the air, in food, through skin contact, and in drinking water supplies. See more information on VOC's below.
How do VOCs get into drinking water?
Most VOCs found in the environment result from human activity. When VOCs are spilled or improperly disposed of, a portion will evaporate, but some will soak into the ground. In soil, VOCs may be carried deeper by rain, water or snow melt and eventually reach the groundwater table. When VOCs migrate underground to nearby wells, they can eventually end up in drinking water supplies. The U.S. Environmental Protection Agency (EPA) estimates that Volatile Organic Chemicals are present in one-fifth of the nation's water supplies. They can enter ground water from a variety of sources. Benzene, for example, may enter ground water from gasoline or oil spills on the ground surface or from leaking underground fuel tanks. Other examples of commonly detected VOCs are dichloromethane (methylene chloride), an industrial solvent; trichloroethylene, used in septic system cleaners; and tetrachloroethylene (perchloroethylene), used in the dry-cleaning industry. Public water systems are required to be monitored on a routine basis for contamination. For private water supplies, however, it is the homeowner's responsibility to regularly have water quality evaluated.
What are the health risks associated with VOC contamination?
VOCs vary considerably in their toxic (or harmful) effects. Drinking water containing high levels of volatile organic compounds (VOCs) may be harmful to human health. Volatile organic compounds may have a variety of harmful health effects. At high levels of exposure, some VOCs may be harmful to the central nervous system, the kidneys or the liver. Some VOC's are known or suspected carcinogens (cancer causers). Current scientific theory on how cancer starts indicates that even a small level of exposure to a carcinogen may cause an equally small level of risk to some people.
Home Water Treatment Systems
Water treatment systems are available which can remove or reduce VOCs. Some home filter systems - such as activated carbon filters - can effectively remove VOCs if they are properly installed and maintained. Granular activated carbon (GAC) filters are typically used to reduce VOC levels in home drinking water. Filtration systems may be installed for point-of-use treatment at the faucet, or point-of-entry treatment where water enters the home. Point-of-entry systems are preferred for VOCs because they provide safe water for bathing and laundry, as well as for cooking and drinking. (VOCs may enter the body through skin absorption or through inhalation of water vapor.) It is important to determine exactly which contaminants are present in water before choosing a system. Then, treatment systems should be checked periodically to ensure that they are operating properly.