Metro Water Services

Water questions & answers

  • Is it okay to substitute other drinks for the recommended six to eight glasses of water needed each day to maintain good health?
    • Juice, milk, and soft drinks are almost all water, so they do count toward the required daily fluid intake. Nutritionists often recommend tap water because some beverages contain chemicals like caffeine and alcohol that do not help the body maintain fluid balance as well as other drinks.
  • Why does dishwater or the dishwasher leave spots on glasses?
    • The spots that may appear on glassware after washing and air-drying are caused by nontoxic minerals that remain on the glass when the water evaporates. Spots on glass shower doors appear for the same reason. Commercial products are available that allow the water to drain from glassware more completely.
  • What is a watershed?
    • A watershed is a region of land where all water drains -- or "sheds" -- to the same river, resevoir, or other body of water.
  • In towns and cities, what is the major cause of pollution of drinking water sources?
    • The major source of pollution in towns and cities is rainwater that flows into street catch basins ( called urban runnoff or stormwater runoff). While the rainwater alone is not necessarily harmful, it frequently carries untreated waste products form our streets and yards directly to rivers, lakes, and streams -- our drinking water sources.
  • Why is some drinking water stored in large tanks high above the ground?
    • Two reasons. First, this type of water storage ensures that water pressure and water volume are sufficient enough to fight fires, even if the electricity that normally pumps water is turned off. The second reason is to provide an extra source of drinking water during the day when water use is high. The water storage tanks are refilled at night when drinking water use is low.
  • Can I tell if my drinking water is okay by just looking at it, tasting it, or smelling it?
    • No. None of the chemicals or microbes that could make you sick can be seen, tasted, or smelled.
  • When I'm working in the yard, I'm tempted to take a drink from my garden hose. Is it safe?
    • No. The water is safe, but a standard vinyl garden house has substances in it to keep it flexible. These chemicals, which may get into the water as it goes through the hose, are not good for you. In addition, the outside thread opening at the end could be covered with germs.
  • If I travel overseas, in which countries is the water safe to drink?
    • Besides the United States and Canada, the water is generally safe to drink in western Europe, Australia, New Zealand, and Japan. In other countries, you should insist on carbonated bottled water for drinking and brushing your teeth.
  • Is the fluoride and chlorine in my drinking water safe?
    • Yes. When added or naturally present in the correct amounts, fluoride in drinking water has greatly improved the dental health of American and Canadian consumers. Many tests have shown that the amount of chlorine found in treated water is safe to drink, although some people object to the taste. NOTE: even in the correct amounts, fluoride or the disinfectant chloramine in drinking water makes the water unsuitable for use in kidney dialysis machines or aquariums.
  • Why does drinking water often look cloudy when first taken from a faucet and then clears up?
    • The cloudy water is caused by tiny air bubbles in the water similar to the gas bubbles in carbonated soft drinks. After a while, the bubbles rise to the top and are gone. This type of cloudiness occurs more often in the winter, when the drinking water is cold.
  • What is "hard" water?
    • The answer may surprise you. Hardness in drinking water is caused by two nontoxic chemicals usually called minerals -- calcium and magnesium. If either of these minerals is present in your water in substancial amounts, the water is said to be "hard", because making a lather or suds for washing is "hard" (difficult) to do. Thus, cleaning with hard water is difficult. Water containing little calcium or magnesium is called "soft" water. (Maybe it should be called easy, the opposite of difficult.) Water that does not contain enough calcium or magnesium may be "too soft".
  • What is the cost of the water I use in my home?
    • Prices vary greatly around the United States and Canada, but a typical cost is about $2 for 1,000 gallons/3785 liters. At that price you get approximately 5 gallons/20 liters of tap water for a penny.
  • Many areas near the ocean do not have large supplies of fresh water. Why can't ocean water be treated to make drinking water?
    • Ocean water can be treated, but the process is expensive. The cost of converting salt water to drinking water has been estimated at $5 to $7 for each 1,000 gallons/3785 liters instead of the $.30 to $.50 for treating 1,000 gallons/3785 liters of fresh water.
  • Why is ocean water salty?
    • Rainwater doesn't contain any salt, but when it falls on the ground, salt from the soil dissolves in the water as it flows back down to the ocean. When this water evaporates from the ocean, the salt stays behind. This has been going on for more than a billion years. That is why the ocean is now very salty.
From Plain Talk About Drinking Water: Questions and Answers About the Water You Drink by Dr. James M. Symons, published by American Water Works Association.

If you have any questions which are not addressed through this web site, please email sonia.harvat@nashville.gov.