EVER WONDERED how you get your drinking water?

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Monday, March 22, 2010

The sip of water you take from the fountain after recess today has been on quite a journey to get to you. The water probably came from the Potomac River, but it may have originated as far as 100 miles away in Pennsylvania!

In the Washington area, water generally flows from north to south, so rainwater and melted snow from north of Washington, known as runoff, flows into creeks and streams, which eventually lead to the Potomac. Some water, known as subsurface water, seeps into the ground and may take a month to get to the Potomac.

Water is taken out of the Potomac at Little Falls Dam and Great Falls Dam, then piped into a reservoir (a place where water is stored), where it stays for about a day. The water then flows through pipes to a treatment plant, where aluminum sulfate and some lime are added. That causes things such as leaves to clump together in a jellylike substance and sink to the bottom. That takes four to six hours.

Then the water is filtered so that even smaller particles that you can't see, including bacteria, are captured. Then a few things are added to the water: chlorine fluoride, which kills most disease-causing organisms; orthophosphate, which keeps the pipes from wearing down; and fluoride, which is good for your teeth.

Finally the water flows from a big pipe to smaller and smaller pipes and into your school or your house.

There are 1,300 miles of water pipes in the city of Washington. Some of those pipes lie under MacArthur Boulevard and date back to 1853! MacArthur Boulevard was once called Conduit Road. (Conduit is a pipe or tube that carries water.) To protect those pipes, there are limits on how much a truck using that road can weigh.

Today is a good day to think about and appreciate your water. It's World Water Day, and many kids in the world don't have clean water or pipes that carry water to their schools and homes. Drink up!

-- Moira E. McLaughlin

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