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Residential Water Filtration Residential Water Filtration is defined, for this article, as any filtration process used at the consumers home for added protection and water quality. Residential water filtration includes "point-of-use" filters (filters water at faucet) and "point-of-entry" filters (filter all the water entering the home). When comparing the benefits and differences between residential filters keep in mind two simple truths. First, any filter is better than no filter. The choice to be made is simply which filter meets your water filtration needs, which filter requires the least amount of maintenance, and which filter offers the best value (often defined as cost per gallon of water). Second, there is no perfect filter. No matter what companies claim in their advertising, no filter removes 100% of all the harmful contaminants and microbiological problems all the time. However, a high quality carbon based residential filter with ultraviolet light disinfection is the best-known technology and offers the greatest protection and best tasting water available. In almost all cases, this type filter meets or exceeds your water purification needs. With the recent focus on water quality and the problems associated with contaminants in our drinking water, the water treatment industry is experiencing explosive growth. With this growth come different methods and technologies, each with its advantages and disadvantages. For instance, some filters use a physical barrier to block or reject contaminants over a certain size while others remove contaminants by carbon adsorption -kind of like a sponge. Not so common filtration and/or disinfection methods include distillation, ozonation, and ultraviolet light. Also, some filters require periodic maintenance while others are maintenance free, and some filters require costly replacement cartridges while others don't. One point must be discussed before discussing the major residential filtration processes; the importance of minerals in our drinking water. Some filters "de-mineralize" drinking water by removing almost everything, to include the minerals in the water. On the surface this sounds like "just what the doctor ordered", but many doctors argue that the natural minerals in our water are not only beneficial, but also vital to our long-term health. Dr. Zolton Rona, author of "The Joy of Health", states that, "the longer one consumes distilled water, the more likely the development of mineral deficiencies and an acid state." Dr. Paavo Airola, cancer expert and author of "How to Get Well" agrees that, "long term consumption of distilled water eventually results in multiple mineral deficiencies." Nowhere in nature do we find de-mineralized water. Conversely, minerals like calcium, magnesium and potassium are naturally occurring, and although there are two sides to this discussion, I've always believed that our creator put minerals into our water for a good reason - we were meant to have them. Point-of-Use Distillation Distillation is a process where water is separated from certain contaminants by vaporization (boiling). Inorganic compounds like lead, mercury, and natural minerals can be effectively removed, however, distillation is not very effective at removing organic chemicals like benzene, TCE, MTBE and trihalomethanes, since they typically vaporize at a lower temperature than water and pass through with the water vapors. Distillation is a very effective means of disinfection and is most often used in areas where there is a high level of bacteria or virus transmitted through the water. Distillers, as residential point-of-use filters, are not used much in the USA because they produce water very slowly and require a large storage tank. Inexpensive residential distillers produce water at a cost of over 20 cents per gallon. Reverse Osmosis (R.O.) R.O. is a process that exposes water under pressure to a semi-permeable membrane with a very fine pore structure. The membrane acts as a barrier and will physically block extremely small particles, down to 0.009 microns in size. The idea is that anything larger than a water molecule will be blocked and washed away. R.O. filters also require the use of carbon pre and post filters to remove free chlorine from the input (pre-filter) and taste, odor, and many synthetic chemicals like herbicides and pesticides, that are smaller than a water molecule, from the output (post filter), R.O. filtration systems are very effective at filtering most inorganic contaminants (like lead, iron, sodium, potassium, calcium, copper, nitrates, and mercury), total dissolved solids (TDS - that improve water taste, odor and clarity), and biological contaminants (like bacteria, cryptosporidium parvum, and giardia lamblia) However, one must take great care in cleaning and maintaining the membrane because a membrane damaged by chemical attack or mechanical tears or breaks is not detectable and will no longer function properly. Also, bacteria can grow through a membrane within a very short time. For these reasons R.O. filters cannot be certified for microbiological control. The Disadvantages to R.O. filters are: 1. They are more expensive than carbon based point-of-use filters and installation is more costly and complex - R.O. systems require additional plumbing, an air gap, and a separate faucet. 2. Most R.O. systems filter water very slowly, less than one gallon per hour, and require a diaphragmed storage tank (usually two to four gallons) that must be cleaned and maintained to eliminate fouling. 3. R.O. systems waste more water than they produce -usually one to two gallons of wastewater are sent down the drain for every gallon of filtered water. 4. R.O. systems require adequate water pressure - usually 50 PSI or greater to function properly. 5. R.O. systems require extensive maintenance. The typical cost of an R.O. system is from 8 to 15 cents per gallon with some of the high-end "designer systems" costing much more. Carbon Filters Carbon is the most widely used water filtration media because it is versatile, economical, and very effective in reducing typical contaminants while adding nothing detrimental to the produced water. Carbon removes contaminants by adsorption (the chemical or physical bond of a contaminant to the surface, or in the pores, of carbon media) and comes in two types, Granular Activated Carbon (GAC) and Carbon Block. Neither GAC or Carbon Block filters remove nor kill bacteria and virus, but sub-micron rated Carbon Block filters are effective at removing (blocking) Cryptosporidium and Giardia. 1. Granular Activated Carbon - GAC is an EPA preferred media for point-of-use filters because it is versatile, long lasting, economical, and extremely effective at reducing chlorine and organic chemicals like herbicides, pesticides, and Industrial chemicals - the contaminants most often found in our water supply. GAC is also longer lasting than other media and 3 to 15 times longer lasting than Carbon Block. GAC filter are also the lowest cost filter with less than 3 cents per gallon of filtered water achievable on high quality units -this is 15 cents less than carbon block, 35 cents less the R.O. filtration, and 80 cents to 5 dollars less than bottled water. 2. Carbon Block - Carbon Block filtration involves forcing water through a tightly compressed activated carbon block. The carbon block's micron rating is a key determinant as to the level of contaminants filtered (blocked) out. The carbon also has adsorptive qualities, which further reduces contaminants from water. Carbon block filters vary in their micron rating with the more efficient blocks capable of physically blocking particles less than 1-micron in size. However, as the micron rating gets smaller, less water is produced - less than 1/2 gallon of water per minute is common with most carbon blocks. Carbon Block filtration can also be quite expensive when compare to GAC. For instance, a popular faucet mount filter with a 100-gallon capacity carbon block filter will cost about $150.00 per 1,000 gallons of filtered water. A 5,000-gallon high quality GAC Countertop filter will cost about $100.00. |
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A powerfully important, yet very fragile resource, pure water no longer exists on the face of the earth. The speed at which nature's purification process works is in dramatic conflict with the rate at which man is damaging our planet's water supply. Most water sources contain elements that not only affect the taste and odor of the water, but also contribute to a wide range of health problems. Tap water - and even bottled water -often contains traces of contaminants like lead, bacteria, and chemical contaminants that trickle down through the soil from agriculture and industry, eventually ending up in the water we drink. This information, therefore, contains general information about water, water treatment, and water contamination that everyone should know. Learning about the importance of water, the hazards of water contamination and the benefits of residential filtration can be helpful in understanding your water needs and filtration options. After all, there is nothing more important than our health and the health of our family. The Importance of Water The human body is a water machine, designed to run primarily on water and minerals. By weight our body is no less than 70% water and our brain is more than 80% water. As you can see, water is a critical part of our lives, and yet science is just now starting to realize how fundamentally important it is to our health. In the past, medical science was based on the theory that the 25% of our body made up of solid tissue is what determined our health. We now know that it is just the opposite. The solid tissue in our body is, for the most part, a shell for the fluids that make up our existence. Our nervous system is in reality an elaborate transportation system made up of tiny waterways. Every movement and every sensation is the result of our brain sending and receiving signals through our nerves. Tiny messengers, called transporter proteins, travel through the fluid in our nerves to control every aspect of our body. Two main factors affect these transmitters more than anything else we do - how much water we drink and the quality of the water. Although most of us know that we need to drink a minimum of 10 -12 glasses each day for a healthy body, few of us know that the risk of disease associated with contaminated drinking water is a real and present threat. Many illnesses that in the past could not be linked to a probable cause can now be directly linked to the toxins in our drinking water. |
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Water Contamination The causes of water contamination are numerous and range from agricultural run-off to improper disposal of toxic chemicals. We often associate water contamination with "the big factory upstream" but the truth is the majority of the contaminants found in our water can be traced back to improper or excessive use of ordinary compounds like lawn chemicals, gasoline, and cleaning products. Once we realize that there are over 70,000 chemicals currently used in our society, and that everything that goes down the drain, on our lawns, on our agricultural fields, or into the environment will eventually end up in our water improper disposal of toxic chemicals. We often associate water contamination with "the supply, we begin to see just how fragile our water supplies really are. Our use of man made chemicals has become so extreme that we can now find traces of low-level toxins in virtually every water supply on earth. A recent report by the Ralph Nader Study Group - after reviewing over 10,000 documents acquired through the Freedom of Information Act - stated that, "US drinking water contains more than 2,100 toxic chemicals that can cause cancer." The Federal Council on Environmental Quality reports that, "Up to two thirds of all cancers may be attributed to those low level toxins." |
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Fortunately, chlorine is one of the easiest substances to remove from water. Residential filtration, using a high quality carbon based filter, will remove virtually all chlorine from your drinking water at less than four cents per gallon. That's right; you don't need to spend $2.50 for bottled water when you can get better drinking water from a residential filter for pennies on the gallon. The truth is, high quality residential filtration systems are more convenient, more economical, and more capable of producing high quality water. |
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Aside from the health risks related to chlorine, it is the primary cause of bad taste and odor in our tap water. The objectionable taste causes many people - and especially children - to consume less healthful alternatives so billions of dollars are spent each year on soft drinks and other sweetened beverages. Many people turn to expensive bottled water to protect their health and improve the taste, and today bottled water is the fastest growing and most profitable segment of the beverage industry. Millions of dollars are spent on advertising to give the perception that these bottled waters come from pristine mountain springs, when in reality many come from municipal water supplies just like your tap water. Both Pepsi's Aquafina and Coca-Cola's Dasani are bottled at one of their bottling plants using filtered municipal water. |
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Lead in Drinking Water Next to chlorine, lead is the most common contaminant found in tap water. Most lead in drinking water comes from lead lined pipes, lead solder, and brass plumbing fixtures inside your home. In fact, the EPA estimates that 98% of all homes have pipes, fixtures or solder joints that can contribute some level of lead to the tap water. The hazards of lead contamination have received an enormous amount of attention and it is well documented that lead takes its greatest toll on small children. According to the U.S. Department of Health and Human Services, "lead is the number one environmental health threat to our children." The EPA estimates that lead in drinking water contributes to 560,000 cases of learning disorders in children each year. Even low levels of lead can cause reduced IQ's and behavioral problems. In adults, lead in drinking water causes high blood pressure and reduced hemoglobin production. The biggest tragedy of lead in our drinking water is that it is preventable. Again, high quality residential filters can virtually eliminate the crippling effects of lead on our society, and most importantly, on our children. |
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In America we use over 2.2 billion pounds of pesticides each year. That's eight pounds for every man woman and child in our country. It is no wonder that a 1994 study of 29 major U.S. cities by the Environmental Working Group found that all 29 cities had traces of at least one weed killer in the drinking water, and 18 cities had five or more. In Fort Wayne, Indiana, nine different pesticides were found in a single glass of tap water. |
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Chlorine in Drinking Water Even chlorine, which was added to our drinking water in the late 1800's as a disinfectant has been determined to be a contributing factor to the sharp increase in cancer over the past century. According to the U.S. Council of Environmental Quality, "Cancer risk among people drinking chlorinated water is 93% higher than among those whose water does not contain chlorine. In the late 1960's Dr. Joseph Price conducted a study using chickens as test subjects. One group was given chlorinated water and a second group was given water without chlorine. The group given chlorine, when autopsied, showed some level of heart or circulatory disease in every chicken, while the group given chlorine free water had no incident of disease. In Dr. Price's words, "It would be a common sense conclusion that if regular chlorinated tap water is not good enough for the chickens, then it probably is not good. Chlorine is a popular disinfectant used by municipalities because it is inexpensive, considered safe, and easy to test the system's effectiveness. If there is a sufficient level of chlorine measured at the point of use, it is assumed there is proper disinfection. A little too much chlorine is considered better than not enough, so it is not unusual to measure chlorine levels well above the EPA Maximum Contaminant Level (MLC). |
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Ultraviolet Light (UV) Although seemingly new to the average homeowner, the use of UV light as a means of water disinfection has been a proven success for many years. The UV method of germicidal disinfection is now recognized as the preferred method of germicidal disinfection by federal and state regulatory agencies. Also, as the concern of microbiological contamination increases, many people have chosen UV filtration as secondary protection and today there are a number of effective point-of-use UV filters available. It is important, when choosing a UV filter, that the filter meets minimum dosages of 16,000 microwatt seconds per square centimeter. UV is a point-of-contact disinfection system designed for bacteria reduction that does not require the addition of any chemicals and does not alter the taste or quality of drinking water. Further, it is virtually impossible to over treat the water with UV. UV energy is germicidal; it works by penetrating the organism's cytoplasm membrane (protective layer) and attacking the DNA. The DNA is photo-chemically damaged, disabling the cells self-reproducing ability and rendering the cell lifeless. |
