Reverse Osmosis (RO) Water Purification Systems
Reverse osmosis (RO) systems are recommended by the Centers for Disease Control as one of the most effective ways of protecting residential drinking water. RO systems utilize a semi-permeable membrane to reduce contaminants. When water is forced against the membrane, a portion of it passes through, while impurities are left behind and carried away.
When choosing an RO system, look for a unit with a high recovery rate (recovery rate = amount of water produced divided by amount of water used). Generally, a rate of 25% is considered efficient.
Certain RO systems also employ a membrane rinse feature that cleans the membrane with the clean water produced by the system to prolong its life and ensure that it continues to produce only the best-quality water.
Distillation systems boil water to reduce contaminants, and then condense the steam that results, and collect the water in a storage tank. Since certain substances do not vaporize, they do not rise with the steam.
These units operate independently from a home’s plumbing and are generally placed at the point of water use. Distillers can use a lot of energy, may radiate heat, and must be cleaned regularly.
Activated carbon can reduce chlorine, VOCs, tastes, odors, and, in some cases, lead. Carbon filters are available in a wide variety of sizes and styles – from small units that can be attached to the end of a faucet to in-line systems that must be connected to a home’s plumbing.
Filter cartridges must be changed regularly to ensure optimum contaminant reduction. Some systems eliminate guesswork by alerting you when a filter change is necessary.
Ultraviolet (UV) Systems
UV systems destroy microorganisms by exposing them to intense ultraviolet light. Since they disinfect water rather than remove contaminants, UV systems are usually installed with other types of water treatment systems. They are ineffective in cloudy water, however, and constantly use electricity. Bulbs must be changed regularly for the systems to function properly.