The NSF requires the manufacturer to provide a means to alert the consumer when the unit is not performing properly. The NSF and WQA also test and certify treatment devices that claim to reduce hazardous chemicals in drinking water for the rated capacity (for example, those chemicals that exceed the EPA Primary Drinking Water Standards or are suspected to cause illness but for which the EPA has no standard). Devices meeting certain standards are allowed to display the NSF mark on the device, literature and advertising. Periodic testing will ensure they maintain their claims. The treated water quality of all units must comply with EPA Primary and Secondary Drinking Water Regulations. The WQA provides an online listing of products that have been Gold Seal Certified or have passed testing to verify their claims of contaminant removal. These organizations ensure the units remove the specific compound the manufacturer claims to remove at the level stated. The National Sanitation Foundation (NSF) and Water Quality Association (WQA) develop and run independent product testing programs for manufacturers who voluntarily submit their units. Unfortunately, their claims may not be true. Many filters on the market claim to remove or reduce certain contaminants in your water. Keep in mind that the suggested life of the carbon filter is an estimate, so you should pay attention to any reduction in water pressure at the water tap that might indicate the filter is saturated with particles. Before purchasing the unit, ask the dealer if the filter can be replaced, how often it should be replaced, where you can purchase replacement filters and how much they cost. Activated-carbon filters usually are rated by the size of the particles they are able to remove, measured in microns, and generally range from 50 microns (least effective) to 0.5 micron (most effective). Removal rates also are affected by the particle size. The lower the flow rate of the water, the more time the contaminants will be in contact with the carbon and the more adsorption will take place. The efficiency of these filters is determined by the length of time the contaminants are in contact with the carbon. While all are effective, activated carbon block filters generally remove more contaminants because of their greater surface area. Catalytic carbons also may remove hydrogen sulfide gas, which produces the “rotten egg” smell in some well water. Chloramines replace chlorine in the disinfection process and have been found to form trihalomethanes (THMs), a cancer-causing substance. Catalytic carbon is an advanced activated-carbon product designed to adsorb chloramines. Three forms of activated carbon used in water filtration systems are granulated activated carbon (GAC), activated-carbon block and catalytic carbon. Some manufacturers use various blends of carbon to achieve specific water quality and contaminant reduction. Carbon is “activated” by adding a positive charge, which enhances the adsorption of contaminants that have a negative charge. Carbon from coconut shells is the most expensive and most effective form. This will depend on the type and amount of contaminants present in your water.Īctivated carbon can be made from coal, wood or coconut shells. At other times, you may need completely different equipment or possibly a combination of equipment. Sometimes just a single piece of equipment, such as an active carbon filter, is all you need to treat the problem. Understanding the laboratory results will help you select the best and most economical water treatment system. The testing laboratory will be able to answer your questions about your results. If you don’t fully understand the results, don’t assume anything. Once you have the laboratory results in hand, make sure you understand the numbers. Proper sampling and handling for one type of contaminant may cause erroneous results for other types of contaminants. Remember, thousands of substances can contaminate your water, and they all have slightly different chemical behavior. Water sampling requirements can vary among laboratories, so you should contact the laboratory to learn the correct way to take a water sample. Prior to sending in your water sample, determine the contaminants for which you want your water tested. However, just the fact that you have an odor in the water may justify installing a filtration unit.Ī reputable or certified laboratory always should do water testing. Your nose can detect objectionable odors in water, but many laboratories are not capable of accurately measuring the source of the odor unless they use special sampling techniques. Water tests can be done for many contaminants, and some tests can be very expensive. Before purchasing a water filtration system, you need a water test.
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