Water is essential to life. It transports nutrients to our cells, aids in the digestion process, transports wastes out of our bodies, helps maintain a normal temperature, lubricates our joints and quenches our thirst.

There is virtually no place on earth that is invulnerable to water contamination, whether it be from agricultural chemicals, industry, sewage or nonpoint source pollution. In many areas of our country, multiple sources of pollution contaminate sole source drinking water supplies, making it essential that people filter or otherwise purify their water supply.

Common Contaminants Found in Drinking Water

Microorganisms: Virtually all public water supplies contain microorganisms, including bacteria, parasites and viruses. Most of the bacteria and parasites are destroyed by the chlorine that is used by water treatment facilities, but viruses are more difficult to eliminate.

Radioactive Substances: Uranium and radioactive gases (like radon) occur naturally in small amounts in many water supplies. Dumping of low-level radioactive wastes from hospitals and other research or manufacturing facilities may increase this amount to potentially harmful levels.

Toxic Minerals: Inorganic minerals such as cadmium, lead, mercury, aluminum, arsenic, asbestos, barium, chromium, fluoride and nitrate are naturally occurring in water in small amounts, but they may increase to harmful levels if pollution from agriculture or mining contaminates the water supply.

Organic Chemicals: Fertilizers, pesticides, paints, fuels, plastics and dyes are often detected in public water supplies. Research shows that the chlorine used to treat water may combine with some of these substances to form harmful chemical compounds such as chloroform. Water facilities use filtering systems to deal with these contaminants with varying degrees of success.

Additives: Water purification processes include the addition of several disinfectants that, when combined, may create harmful compounds and byproducts. Many flocculants, which clump pollutants for easier filtering, are classified as probable human carcinogens by the Environmental Protection Agency (EPA). Fluoride, a known toxin, is still added to many public water supplies.

Water Purification Systems

Carbon Filters: Carbon block or granular activated carbon filters absorb or physically screen out industrial chemicals and common herbicides and pesticides. Carbon is an effective material, but if particles are loose, water doesn't have sufficient contact time and the water "channels" through, taking the path of least resistance. The effectiveness of carbon can be quickly exhausted by continuously filtering water through "yesterday's" contamination. Block filters are made of powdered activated carbon and are more effective at removing smaller sediment particles. They are held together with adhesives or binders.

Reverse Osmosis ("RO"): RO systems pass water through a synthetic semi-permeable membrane that rejects most contaminants down to the molecular level. Virtually all RO units also have carbon pre or post filters to provide additional treatment. This method, in combination with a large whole-house carbon filter is effective at purifying most public water supplies.

Distillation: Distillers heat water in a chamber where it turns to steam. The steam then passes through a coil where it condenses back into water and drips into a new holding chamber. This is 99% effective for removing lead, some heavy metals, bacteria and cysts from the water. However, if the water is contaminated with organic chemicals that have the same or lower boiling point as water, it will transfer and concentrate those chemicals in the holding chamber. Most industrial chemicals, herbicide and pesticides have boiling points below that of water.

Hybrid Systems: Water purification systems using microstraining, molecular capture or electrostatic removal are able to remove most industrial and pesticide products as well as harmful bacteria. These systems are chemical-free and do not use electricity. Be sure to read our section on Bottled Water.

Product Information

Fresh Water Systems – Water filters and systems.

General Ecology, Inc. – Manufacturer of "Structured MatrixTM" Drinking Water Purifiers.

Krudico, Inc. – Manufacturer of whole-house activated carbon filters.

Ozark Water and Air Services – Water filters and water testing kits.

Pure Water Inc. – Manufacturer of distillers for drinking water.