Clean Water Supply
Water basics: In general, tap water in the United States is perfectly safe for human consumption. However, sometimes you may notice a funny color, odor or taste. These often come from otherwise harmless contaminants like chlorine, sulfur, iron and manganese. You can get rid of these problems and enhance the clean water supply easily by using a conventional activated carbon filter, available at many retail stores and even supermarkets.
But if your water contains dangerous levels of other pollutants, you'll need to choose a water treatment technology that is appropriate for eliminating the toxins. For the sake of discussion, it's easiest to group toxic pollutants into four categories: organic chemicals, inorganic chemicals, radio nuclides and microbiological organisms.
Organic chemicals include solvents, pesticides, synthetics, resins and other manmade chemicals; many are known as volatile organic chemicals (VOCs). Inorganic chemicals include nitrates and nitrites, asbestos, fluoride and metals such as arsenic, mercury and the most notorious lead. Many of these occur as natural mineral deposits. Some, such as copper and lead, leach into water as it travels through pipes; treatment by your water utility doesn't remove them. Radon gas, the most common radio nuclide, occurs naturally in a number of regions, including Western mountain states and parts of the Northeast. Microbiological contaminants, including protozoa, bacteria and viruses, are normally killed by chlorinating and other treatment.
These dangerous pollutants are rare, but the water filter industry often plays up fears to generate sales.
If you have any questions about your water's safety, call your water supplier or health department and request copies of water treatment reports. Less than 10 percent of the water produced by public systems is used for drinking and cooking. The vast majority of our tap water is used by business, industry and for purposes such as bathing, washing clothes, etc. While our public utilities provide water that is safe to drink, it is neither practical nor cost-effective for them to produce high-purity water, since most uses do not require this level of quality. Impurities in your water can be broken down into four categories: sediments, chemicals, dissolved solids and microbiological organisms. Sediments include dirt, rust and particles of plant or animal matter that are suspended in water.
Sediments: Sediments are the largest water-borne impurity, although most are too small to be seen. Sediment problems include cloudy, unappealing water and clogging of water passages in appliances.
Chemicals are molecules, or groups of atoms. The most common of these are chlorine compounds which are added to tap water to control the growth of bacteria and algae. Chemicals can cause bitter, oily tastes and unpleasant odors. Some, including trihalomethanes, as well as many pesticides, herbicides, and industrial solvents are regulated by the government. Dissolved solids (atoms) are extremely small, usually less than 8 ten thousandths of one micron in size. Some dissolved solids (e.g. hardness minerals, alkalinity, sulfate, etc.) are harmless but may cause objectionable taste and scale problems normally associated with hard water. Others, such as lead, nitrate, sodium, fluoride, arsenic, mercury, etc., can be harmful. The amount of these contaminants allowed in drinking water is limited by government standards. Total Dissolved Solids (TDS) refers to the overall amount of all dissolved solids found in any one tap water sample.
Disease-producing microbiological organisms are rare in water that comes from the ground. The earth's aquifer filters out such organisms as giardia, e-coli and cryptosporidium. However these organisms are more common in tap water that comes from the surface.
Filtering: If you are buying a filtration system, consider filtering all incoming water instead of just putting a filter on the tap. Why? Hard water is the most common problem found in the average home. It contains dissolved hardness minerals like calcium, manganese and magnesium which dilute water's natural ability to wash things.
Water softeners: Water softeners reduce the mineral content of hard water, substituting sodium for minerals such as calcium, magnesium and iron. This also reduces mineral buildup in pipes and appliances. But because they add sodium salt, a potential health hazard to water, it's smart to install a softener only on the hot-water side of a water supply system so it won't affect the drinking water.
Filters: A reverse osmosis (RO) filter removes nearly all contaminants, particularly when combined with carbon filtration. Installed beneath the sink and connected directly to plumbing, an RO filter forces water through a membrane that permits only pure water molecules to pass.
A carbon prefilter connected to most RO filters removes sediment and some contaminants that the membrane won't catch. Carbon postfilters attached to some RO filters are used to "polish" the taste of the water. A popular choice for many people today is to have distilled or filtered water delivered to your home. Many companies offer this service.