Water Filtration

Americans spend billions of dollars each year on home water treatment units. According to the Water Quality Association, more than four out of 10 Americans currently use a home water treatment unit of one type or another. These units range from simple pitchers costing less than $20 to sophisticated reverse osmosis systems  costing hundreds of dollars.

Some people use a home water treatment unit to improve the taste of their tap water. Others treat their water because of health concerns, but regardless of why the water is treated, the Environmental Protection Agency (EPA), the agency that sets and enforces national standards for the tap water provided by public water systems, says that drinking water in the U.S. can reasonably be expected to contain at least small amounts of some contaminants. As long as those contaminants are at levels no higher than EPA standards, the water is considered safe to drink for healthy people. ( Individuals with immune systems that are weakened by AIDS, chemotherapy or transplant medications are more vulnerable to microbial contaminants in drinking water. Those who wish to take extra measures to avoid waterborne contaminants can boil their water for a full minute or use a point-of-use filter such as a reverse osmosis unit).

Before purchasing a home water treatment unit, consider local water quality, cost and maintenance of the unit, product performance and certifications to make sure that the unit will meet your needs.

Water filtration and purification are the processes used forremoving contaminants from a raw water source. The goal is to produce water for a specific purpose with a treatment profile designed to limit the inclusion of specific materials; most water is purified for human consumption (drinking water). Water purification may also be designed for a variety of other purposes, including to meet the requirements of medical, pharmacology, chemical and industrial applications. Methods include, but are not limited to: ultraviolet light, filtration, water softening, reverse osmosis, ultrafiltration, deionization and powdered activated carbon treatment.

Water purification may remove: particulate sand; suspended particles of organic material; parasites, Giardia; Cryptosporidium; bacteria; algae; virus; fungi; etc. Minerals calcium, silica, magnesium, etc. and toxic metals (lead, copper, chromium etc). Some purification may be elective in the purification process, including smell (hydrogen sulfide remediation), taste (mineral extraction), and appearance (iron incapsulation).

Governments usually dictate the standards for drinking water quality. These standards will require minimum / maximum set points of contaminants and the inclusion of control elements that produce drinking water. Quality standards in many countries require specific amounts of disinfectant (such as chlorine or ozone) in the water after it leaves the water treatment plant (WTP), to reduce the risk of re-contamination while the water is in the distribution system.

It is not possible to tell whether water is safe to drink just by looking at it. Simple procedures such as boiling or the use of a household activated carbon filter are not sufficient for treating all the possible contaminants that may be present in water from an unknown source. Even natural spring water - considered safe for all practical purposes in the 1800s - must now be tested before determining what kind of treatment, if any, is needed. Chemical analysis, while expensive, is the only way to obtain the information necessary for deciding on method of purification.