Water

By Tim Taylor

No “new” water

Roughly two-thirds of the planet is covered by water, but only one percent of all the world’s water can be used for drinking. Nearly 97 percent of the world’s water is salty or otherwise undrinkable, and the other two percent is locked away in ice caps and glaciers. Despite what you may think, there is no “new” water. Whether your source water is a river, lake or well, Americans are using the same water the dinosaurs used millions of years ago. And using quite a bit of it. The average American uses about 100 gallons of water each day, according to the Environmental Protection Agency, while the average European only uses 50 gallons a day. For the most part, we use water treated to meet drinking water standards to flush toilets and wash dishes, clothes, and cars. In fact, 50 to 70 percent of home water is used for watering lawns and gardens. And nearly 14 percent a typical homeowner pays for is never even used, it leaks down the drain.

Two sources

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Do you know where your drinking water comes from? Odds are it comes from one of two sources, either from surface water or ground water. The water that systems pump from sources open to the atmosphere, such as rivers, lakes and reservoirs, is known as surface water. Water pumped from wells drilled into underground aquifers, geologic formations containing water, is called ground water. The quantity of water produced by a well depends on the nature of the rock, sand, or soil in the aquifer from which the water is drawn. Large-scale supply systems tend to rely on surface water resources, while smaller systems tend to use ground water. Water utilities treat nearly 34 billion gallons of water every day. The type of treatment varies with the source and quality of the water. Surface water systems require more treatment than ground systems because they are directly exposed to the atmosphere and runoff from rain and melting snow.

Must meet standards

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Where did that glass of water you’re drinking come from? An underground network of pipes typically delivers drinking water to the homes and businesses served by the water system. Small systems serving just a handful of households may be relatively simple, while large metropolitan systems can be extremely complex, sometimes consisting of thousands of miles of pipes serving millions of people. Drinking water must meet required health standards when it leaves the treatment plant. After treated water leaves the plant, it is monitored within the distribution system to identify and remedy any problems such as water main breaks or growth of microorganisms. All sources of drinking water contain some naturally occurring contaminants. At low levels, these contaminants generally are not considered harmful. Removing all contaminants would be extremely expensive, and in most cases, would not provide increased protection of public health.

How much?

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It’s a question that’s puzzled us for centuries. Exactly how much water do we need to drink every day? Studies have produced varying recommendations over the years, but in truth, your water needs depend on many factors, including your health, how active you are and where you live. If you exercise or engage in any activity that makes you sweat, you need to drink extra water to compensate for the fluid loss. Hot or humid weather can make you sweat and requires additional intake of fluid. Heated indoor air also can cause your skin to lose moisture during wintertime. When you have a fever or diarrhea, your body loses additional fluids. In these cases, you should drink more water. Women who are expecting or breast-feeding need additional fluids to stay hydrated. Large amounts of fluid are used especially when nursing. If you’re concerned about your fluid intake, check with your doctor to determine the amount of water that’s best for you.

Fluoride

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About two thirds of the people in the U.S. are served by public water supplies containing enough fluoride to protect their teeth. Water fluoridation prevents tooth decay mainly by providing teeth with frequent contact with low levels of fluoride throughout each day and throughout life. Even today, with other available sources of fluoride, studies show that water fluoridation reduces tooth decay by about 25 percent over a person’s lifetime. Water fluoridation is not only safe and effective, but it is also cost-saving and the least expensive way to deliver the benefits of fluoride to all residents of a community. For larger communities of more than 20,000 people, it costs about 50 cents per person to fluoridate the water. It is also cost-effective because every $1 invested in this preventive measure yields approximately $38 savings in dental treatment costs. This method of fluoride delivery benefits all people regardless of age or economic status.These programs were first broadcast the week of September 7, 2015.

T. Glenn Pait, M.D., of UAMS is the host of the program.