Friday, April 24, 2009

Water Filters


Water Filters

Get out the lead, and more

Most drinking water in the United States tastes good and is good for you. There's no need to filter it. But some people don't like the way their water tastes. And others have reason to believe their water is contaminated with lead, pesticides, arsenic, or other unsavory substances.

If you drink bottled water because you're concerned about water quality or taste, switching to home filtered water is usually easier on your wallet and on the planet (52 billion plastic bottles and jugs wind up in U.S. landfills and incinerators each year). Many of today's water filters are easy to use and inexpensive. If you plan to use a filter, here's what you need to know.

Top Tips

At home

  • Improve the taste. If you don't like the taste of your water, a simple activated carbon filter (either a carafe filter or a device installed on or near the faucet) will likely improve it. An even simpler way to eliminate the chlorine taste is to let a uncovered pitcher of water sit in the refrigerator overnight. The chlorine will be gone by morning.

  • Investigate contaminants. Because different filters remove different kinds of contaminants, you first need to find out what's likely to be in your tap water. Some substances, like arsenic, radium, and radon, occur naturally in the water in some areas. Others, like pesticides or nitrates from fertilizer and animal waste, make their way into water supplies from agricultural or industrial activities. Call your water company or read its annual water quality report, which must be sent to customers every year. The report will list recent water quality violations and disclose which contaminants may be a problem in your area.

    If you're among the 15% of Americans who rely on well water, the U.S. EPA recommends you have it tested annually for impurities such as coliform bacteria and nitrates. Ask your local or state health department for a list of state-certified testing labs. If you don't want to have the water tested, at least ask your health department about the types of contaminants likely to affect local well water.

  • Choose a filter--or not. After reading the municipal water report or having your well water tested, you might decide you don't need a water filter. But if there are tastes or specific contaminants you're concerned about, here are your choices:

    • Carafe filter. These pitchers have disposable filters. Most use granules of activated (positively charged) carbon to attract and trap contaminants. Cost: $15 to $25.

      • Improves taste. Reduces chlorine (some models also reduce chloramine, a disinfectant used by some water agencies instead of chlorine). Some models reduce lead, pesticides, or other contaminants; check label. Filter needs regular replacement. Convenient if you don't drink a lot of water and don't want filtered water for cooking.

    • Faucet, showerhead, refrigerator, countertop, and under-sink filters. Most use blocks of activated carbon to attract and trap contaminants. Some use fabrics, ceramic screening, or fiber as the filter. Cost: $20 to $500.

      • Improves taste. Reduces chlorine (some models also reduce chloramine). Some models reduce lead and other heavy metals, parasites, VOCs, pesticides, radon, or other contaminants; check label. Filter needs regular replacement. More economical than carafe filters if you drink a lot of water or want to use filtered water for cooking.

    • Reverse osmosis. Uses pressure to force water through a semi-permeable membrane, leaving behind contaminants. Cost: $150 to $900.

      • Improves taste. Kills bacteria and viruses. Removes lead and other heavy metals, nitrates, certain parasites, and many chemical contaminants (such as pesticides and petrochemicals); check label. Installed under sink. Filters require periodic replacement. Delivers water very slowly. Wastes three to five gallons of water for each gallon produced (because there's "reject water" that carries the concentrated contaminants, and is typically plumbed to the sink's drainage pipe).

    • Distiller. Boils water and collects the recondensed, purified water vapor. Cost: $100 to $2,000.

      • Kills bacteria and viruses. Removes lead, and other heavy metals, nitrates, radium and most chemical contaminants; may not remove some gases such as VOCs or radon; check label. Low-capacity distillers sit on the countertop. High-capacity devices are large freestanding units. Delivers water very slowly. Uses a lot of electricity. Removes water's natural minerals; may taste flat.

    • Water softener. Reduces hardness in the water by replacing calcium or magnesium ions with potassium or sodium ions. Cost: $400 to $1,600.

      • Reduces scale (calcium and magnesium mineral deposits) on plumbing fixtures and pipes and makes lathering up easier. Removes radium and barium. Installed as a whole house system. Filtration medium must be periodically regenerated with salt or potassium chloride; regeneration process wastes water.

    • Ultraviolet disinfection. UV light disinfects water, reducing microorganisms. Cost: $70 to $800.

      • Kills bacteria and viruses. Installed under sink or as whole house treatment, often combined with a carbon filter. Uses electricity (a 40- to 100-watt ultraviolet lamp remains on continuously).

When shopping, look for

  • Certification. Make sure the water treatment product you buy has certification from NSF (formerly the National Sanitation Foundation) International, Underwriters Laboratories, or the Water Quality Association. (An EPA registration number is not a performance certification; it merely means the product is registered as a device that contains antimicrobial agents.)

Other Considerations

  • Maintenance. All water treatment devices need regular maintenance to work properly. Follow the manufacturer's directions. With some systems, failing to replace filters or follow maintenance procedures can lead to the buildup of bacteria or other contaminants on the filter. With some systems, the yearly cost to replace filters can be two to three times the initial cost of the device.

  • Whole house or point of use? Whole house treatment systems are installed where the main water line enters the home, so all the water gets treated, not just your drinking water. That's a plus if you're trying to eliminate scaling or staining problems. But if it's just drinking water you're concerned about, a point-of-use filter at the kitchen sink will meet your needs. Point-of-use filters come in a variety of configurations, depending on the type of filtration system: some require no plumbing and screw right onto the faucet or sit on the countertop; others go under the sink and require some basic plumbing work.

  • Lead pipes. Water that's free of contaminants when it gets to a house can pick up lead from certain types of old pipes. Some house built before World War II still have their original lead-based water pipes. These should be replaced. Copper pipes installed before 1988 may have lead-based solder that can leach into the water. Have a plumber inspect the joints, or have the water tested for lead, especially if there are children in your household. Children are particularly susceptible to brain and nervous system damage from lead poisoning. If lead turns up in the tests, you can install filters certified to remove lead (or replace the pipes, but that can be pricey). Here's an alternative that doesn't cost anything: If the cold water tap hasn't been turned on for a few hours, run it for three minutes to clear out any water that may have picked up lead. Lead is more likely to leach into hot water than cold, so if you know there is lead in your pipes, never use water from the hot tap for cooking or drinking.

  • Emergency treatment. If a natural disaster such as a flood contaminates municipal water supplies or your well water, boil the water for a full minute to kill microbes (three minutes if you live at a high altitude). Store the water in a clean, covered container.

Benefits... you and your health
If your water has an off-taste, a basic carbon filter will usually improve it. If you're worried about specific contaminants, a filter or other treatment device can deliver healthier water--provided you install the right filter for that particular contaminant. your wallet
In most cases, a home filtration system will be cheaper than bottled water. Initial costs range from $20 carafes to systems that cost thousands of dollars. the environment
Switching from drinking bottled water to home-filtered water reduces the number of petroleum-based bottles that need to be manufactured, the amount of plastic waste that winds up in landfills and incinerators, and the fuel expended in delivering bottled water to homes.

Common Mistakes

Buying bottled water. Many studies have shown that bottled water isn't necessarily any healthier than tap water. In fact, the bottled water industry is less regulated than municipal water supplies. More than a fourth of bottled water brands are merely repackaged municipal drinking water. And tests have come up with a number of brands contaminated with bacteria, arsenic, and other potential hazards.

Getting Started

  • Faucet-mounted filters take only a few seconds to screw onto the faucet. Under-sink filters are fairly easy to install, although a reverse-osmosis filter takes a bit more effort because it needs to be hooked up to the sink's drain to discharge wastewater. A whole-house filter may take a few hours to install and typically involves cutting into the water supply line, but won't be hard for a handy DIYer.

  • Alternatively, you can buy a system and have a plumber install it, or purchase a filtration system from the plumber.

  • For general advice on what questions to ask contractors and other tradespeople, see our "What to Ask Your Contractor" article.

  • For more details on specific filters, use the online NSF guide.

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