Units that contain carbon usually in the form of activated charcoal. Very effective in removing odor, chlorine, pesticides, and organic compounds. Not as effective for bacterial removal or heavy metals and hard minerals. Attracts particles from the water until it reaches the saturation point.
Designed to kill bacteria with chlorine. Has a tendency to leave an objectionable taste and odor. It also may form a potentially dangerous element.
Capable of removing bacteria and some chemicals from water, but cannot remove nitrates.
Contains a sediment filter and an activated filter. Effective in removing 60 to 90 percent of most minerals and inorganic compounds. Does not produce a large amount of water in a 24 hour period.
Boils water to produce a steam, which is then cooled to produce relatively clean water. However, this method will usually not clean the water of gases.
The best method to remove radon gas which is one of the worst environmental hazards to man. The EPA estimates that over 8 million people may be at risk in the United States from high radon levels in their water.
Screen that filters out suspended particles such as detergents.
Effective for the removal of bacteria. Usually installed on wells with other types of filters.
Demineralizes the water by passing a current of electricity through it to remove inorganic minerals. This method is not very effective in removing organic substances or bacteria.
Utilizes a highly activated form of oxygen to burn up bacteria.
Removes hard minerals such as calcium or magnesium and replaces them with sodium through a process of ion-exchange. The addition of the sodium softens the water and makes it more effective for washing clothes, bathing, and doing dishes. The high salt content does not make it recommended for drinking.
Uses membranes similar to those used in reverse osmosis units, but utilizing a different method of operation. The membrane is designed to collect relatively large organic molecules as they remove dissolved inorganic solids or bacteria.
See also:
Water Facts
Types of Water
Break the Bottled Water Habit
Bottled Water: Did you know?
Drink a Glass of Water! -- Essential health and well-being tip
Why Water? -- Convincing reasons why we need to drink water!
