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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.

Quote Left before deciding which kind of home treatment system, you should begin by learning more about your tap water Quote Right

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:
  • Adsorptive media:Liquids, solids, dissolved or suspended matter adhere to the surface of, or in the pores of, a solid material. Carbon filters use this technology.
Picture of high flow carbon filter
  • Aerators: Aerators force water to travel over air jets. Contaminants that easily turn into gases, such as gasoline components and radon, are removed. Other contaminants are not. The water may be additionally filtered after it passes through this system to remove additional contaminants. Caution must be taken regarding the placement of an aeration system due to the venting of volatile gases. Aerated water may increase corrosion of household plumbing, which may lead to higher levels of lead and copper in drinking water. In general, aeration systems are more expensive and difficult to maintain than other water treatment systems and are most often used when high levels of VOCs or radon are detected in drinking water.
Sample picture of Aerators
  • Water Softeners: Water Softeners use a cation exchange resin, regenerated with sodium chloride or potassium chloride, to reduce the amount of hardness (calcium, magnesium) in the water. The hardness ions in the water are replaced with sodium or potassium ions. Ion exchange water softeners simultaneously remove radium and barium while removing water hardness. 
Picture of electronic heavy duty water softener


Point-of-Use Devices:

  • Filter pitchers: Water filtration pitchers are an affordable and commonly used freestanding home water treatment device.  Most water pitchers use granular-activated carbon and resins to bond with and trap contaminants. Yet, specific contaminants removed vary by model and depend on the pore size and other factors. An activated carbon filter, by itself, is not designed to remove all disease-causing organisms. Carbon filters have a specific shelf life and should be replaced regularly according to the manufacturer’s instructions.
Sample picture of filter pitchers
  • Filters that attach to a faucet or are installed under the sink for a drinking water third faucet: these filters generally use the same technologies as their pour-through pitcher counterparts. Some filters use fabric, fiber, or ceramic screening to physically remove contaminants. The most common types use a molded block of activated carbon. Like filter pitchers, shelf lives and specific contaminants removed vary. So, read the label and instructions carefully.
Sample picture of filters that attach to a faucet
  • Distillers: Distillers heat water to the boiling point, and then collect the water vapor as it condenses, killing disease-causing microbes and leaving most chemical contaminant behind. Contaminants that easily turn into gases, such as gasoline components or radon, may remain in the water unless the system is specifically designed to remove them. Distilled water may taste flat to some people because the water’s natural minerals and dissolved oxygen often have been removed.
Sample picture of distillers
  • Reverse Osmosis Units: Reverse osmosis units force water through a semi-permeable membrane under pressure, leaving contaminants behind. Reverse osmosis units use approximately four gallons of water to produce one gallon of pure water, but they are effective in eliminating all disease causing organisms and most chemical contaminants.

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