(Part 2 of a two-part series. See Part 1: Is my drinking water really safe?)
The occasional, sensational news story about a drinking water problem somewhere in the United States could lead you to think that it is a big problem in this country. It’s not. American water utilities produce safe drinking water. But, the water can become contaminated between the time it leaves the treatment plant and when it comes out of your faucet. Or, your household may be one of an increasing number that gets its drinking water from a private well that could be contaminated.
In either case, prudence dictates that you get your water tested. This can be a costly proposition, however, if you ask a lab to test for all the substances that might be there. Screening for all the possibilities could run to several thousand dollars.
A more cost-effective approach is to test for the substances that are most likely to be in the water, said Richard Mass, an environmental sciences professor at University of North Carolina-Ashville, who has studied drinking water treatment issues in the Unites States for many years. In this country, Maas said, about 95 percent of drinking water contaminants fall into five broad categories: lead; arsenic; drinking-water by-products, which are formed when a disinfection agent such as chlorine reacts with a small amount of organic matter in the water; industrial chemicals; and microbiological cysts that can bring on giardia or cryptosporidium when ingested.
Getting your water tested, however, is only the first step. Then you have to get the correct filter. Different types of filters take out different contaminants, and there is no “one size fits all” solution.
The least expensive and most widely available filters are the activated carbon type (some refer to this type as an activated charcoal filter). These can be cartridges in a simple pour-through pitcher, a device that attaches to your kitchen faucet, a device that is integrated into the faucet (aesthetically less awkward but much more expensive), or a larger unit under the sink that has its own faucet. This latter type may require a plumber to install, but it may also remove more contaminants than the smaller ones.
The most basic carbon filters remove chlorine taste and odor and particulates suspended in the water. The more sophisticated ones have added media that can remove an impressive number of substances, but you have to check carefully to make sure that the ones removed are the ones that concern you. For example, Culligan’s UnderSink Charcoal Filtration System Model SY-2650 lists, on its packing box, 55 substances that it removes, but arsenic is not on the list. An activated carbon filter can remove arsenic, but only if a specific media for this has been added.
A less common and more expensive type of drinking water filter is areverse osmosis type. It also goes under the sink, may require a plumber to install, and has its own faucet. With reverse osmosis, water is forced through a membrane that removes most contaminants, but it is always sold with pre- and post-carbon filters. Together, the two filtration methods remove more than either one alone.
But, it should be noted, reverse osmosis systems have their down side. They waste a lot of water–for every gallon they purify, two to five gallons are discarded. The main complaint of most consumers, though, is speed. Most models take 4 to 12 hours to produce 2 to 3 gallons of water, which is stored in a tank under the sink. As the average family of four only consumes about 2 gallons of drinking water a day, this can be workable for regular use–every night the system can replenish itself–but if you entertain frequently, it’s not a great solution. However, GE Water Technology’s Marlin reverse osmosis system has no tank and delivers ½ gallon of water a minute. The system will be available through independent water treatment dealers starting August 1, but, it’s pricey–the cost will be about $700 to $1,000, compared to a conventional reverse osmosis system at around $200 to $350.
Another new wrinkle in the reverse osmosis filtration biz is one that in combination with carbon filters removes bacteria and viruses. The carbon blocks are made by KX Industries, an Orange, Conn.-based firm that supplies the carbon filter components for most filtration manufacturers in the United States. Until now, no carbon filter maker has made this claim, and there was no test to certify it. KX, working with the EPA and the State of California Department of Health Sciences, designed a certification test, which was then administered by a California-certified microbiological lab.
Beginning in August, KX’s Matrikx filter will be available at Costco in the Watts Premier Reverse Osmosis System. KX will market a stand-alone carbon filtration system to be called the Matrikx Microbiological Barrier under its own Matrikx brand in October.
For homeowners with city water, KX’s Matrikx filter will not be that significant, but it can be a real boon to homeowners whose water source is a private well and who also have a septic field or live near one. The real beneficiaries, however, will be the 3 billion people who live in third-world countries without access to safe drinking water. For that market, KX is manufacturing a World Filter, which will differ from the one sold in the United States. The World Filter is intended for people who carry water from a central village source to their homes, as well as those whose municipal water is contaminated.
Another drinking water filtration possibility is a distiller. I tried out a Kenmore Model 34480, which took about five hours to distill three quarts. With this type of system, water is placed in one chamber and boiled to produce steam, which is then passed through a charcoal filter and condensed back into water in a separate chamber. The distilling process is extremely effective at removing most contaminants, and I found the taste pleasant.
But, both the EPA and the National Sanitation Foundation (NSF), an organization that certifies water filtration devices, caution that some contaminants, such as volatile organic chemicals (VOCs), readily convert into gas and these may be carried over into the chamber with the purified water. If you have well water and discover, for example, that it contains MTBE, a gasoline additive that can leak out of underground storage tanks and get into ground water, a distiller would not be your best option.
Once you’ve decided on a filtration system, how sure can be you be that the filter removes what the manufacturer claims? You should look for a certification from NSF, Underwriters Laboratory (UL), or the Gold Seal of the Water Quality Association. But fraudulent claims have not been an issue in this industry. Maas, who has tested dozens of water filters over the last 17 years, has found almost no case where a manufacturer claimed to remove something and didn’t because, he explained, “technically it’s not that hard to do.”
The main issue with filters is not false claims but bad homeowners maintenance, Maas said. A carbon filter mechanism gets used up and needs replacement every few months, depending on how many gallons of water you use a day. Some filtration systems now have a light that slowly changes color from green to a red to indicate replacement is required. But most do not, and most city water does not contain enough particulates to clog the mechanism, which would also signal that the filter should be replaced. You just have to mark your calendar when you install a new filter and follow the recommendations of the manufacturers for when to replace it, Maas advised.
With a typical municipal water supply a reverse osmosis membrane needs replacement every three to five years, and the carbon filter components of the mechanism should be replaced every six months advised Sam Karge of GE Water Technologies.
Another drinking water option, though the most expensive over time, is bottled water. Your local grocery store will sell a large selection, nearly all of them bearing labels with pictures of snow-covered mountains or some other distant and presumably pristine water source. But much of the water, including that of some of the top-selling brands, is simply glorified tap water. In its August 2000 report, Consumer Reports found that Pepsi’s Aquafina Purified Drinking Water “originates from 16 sources–mainly municipal water supplies” and Coke’s Desani is to be “purified from municipal sources.”
Information on drinking water issues:
The U.S. Environmental Protection Agency, www.epa.gov
The Natural Resources Defense Fund, www.nrdc.org
The National Sanitation Foundation, www.nsf.org
Information on filters:
The Marlin Reverse Osmosis System, www.gewater.com. Click on “filtration spectrum”
The Matrikx Microbiological Barrier, www.kxindustries.com
For information on testing your drinking water:
Your local health department should have a list of state certified labs. A less expensive alternative, which includes participating in an on-going research project on drinking water in the United States, is to get it tested thru the Environmental Quality Institute at the University of North Carolina-Ashville. Contact the lab at www.leadtesting.org or at CWLT, Environmental Quality Institute, UNC-Ashville, N.C. 28804.
Questions or queries? Katherine Salant can be contacted at www.katherinesalant.com.
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