Drinking water 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. However, some people use a home water treatment unit to improve the taste of their tap water, and others threat their water because of health concerns. These units range from simple pitchers costing less than $20 to sophisticated reverse osmosis units costing hundreds of dollars. Before you purchase a home water treatment unit, you may want to consider local water quality, cost and maintenance of the unit, and product performance to make sure that the unit will meet your needs.
before deciding which kind of home treatment system, you should begin by learning more about your tap water |
First, you can begin by leaning about your tap water. You can contact your local water supplier and ask for the annual water quality report. This report lists the levels of contaminants that have been detected in the water and shows how these levels compare with EPA’s drinking water standards. Some contaminant levels remain constant throughout the year, while others vary according to season, weather, or from house to house. For example, lead typically occurs when it leaches from the lead pipes and solder that are in some homes. If you are concerned about a contaminant whose level may vary, consider getting your water tested by state certified laboratory (as the test can be costly, try to limit the problems that specific to your situation) or purchase a home water treatment unit.
Consider using point-of-use filters (personal use, end of tap, under sink) that remove particles one micrometer or less in diameter. A water filter is composed of a screen with many microscopic holes. The smaller the holes, the more contaminants the filter can remove. Filter holes are measured in microns. When considering filter size in traditional carbon or sediment filter, look for an absolute (the largest hole), not a nominal(the average hole). In most cases, nominal particulate rating (0.5 µm) is for >85% of particles a given size as determined from single-pass particle counting results. Absolute particulate rating (1 µm) is for >99.9% of particles of a given size as determined from single-pass particle counting results.
For the grestes assurance of removing microscopic parasite that lives in the intestine of infected animals and human, we still recommendate using reverse osmosis water system (0.0001 micron), or labeled as “absolute one micron filters” (carbon filter or ceramic filter). The following information is an example of contaminants and their size in microns:
- Giardia Iamblia - 8 to 12 microns
- Cryptosporidium parvum - 4 to 6 microns
- Viruses - 0.004 to 0.1 microns (Generally, only a few filters, such as ultra filters and reverse osmosis, have holes small enough to assure removal of all viruses. However, viruses can be killed using a disinfectant.)
Different units remove different contaminants or classes of contaminants from the water. For most contaminants, a point-of-use device is effective for treating only the water that is consumed. And, a point-of-entry device can reduce concentrations of these contaminants and others that cause aesthetic problems such as scaling, staining, or odor. Normally, sophisticated units such as reverse osmosis use multiple filters to remove several types of contaminants and to provide backup protection in case one treatment fails. However, all units require some maintenance, and it is important to follow the manufacturer’s recommendations for replacements.
Point-of-Entry Devices:
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