2008-09-06 / Editorials & Letters

Water problems demonstrate importance of chemistry

Editor:

On behalf of the National Mole Day Foundation, I wish to commend your paper for your August 30 story - "Millersport water treatment plant to restart soon."

Your paper did a good job of describing the chemistry of the water department's recent problem. The average water customer, young and old, turns on the faucet, and expects their water to be safe, and hopefully colorless (non-staining), and softened. The detail of your article educated the readership of your paper in the chemistry of the water purification and softening process.

As you mentioned, Millersport has recently built a new water plant and increased water capacity in their service area. Their two new wells at a depth of 125 feet lower than previous wells instituted a scientific process in searching for an answer to discolored water. Flushing 100 hydrants seemed to rule out the iron in the mains and at the hydrant locations causing the problem. Therefore, maybe something was in the water that was not in the water at 200 feet down. Your article indicated an excess of iron and manganese, which when oxidized in the chlorination process (after the filters) would give the colored water in the system and lines.

You gave good details with the chemicals that needed to be added to precipitate the ions, and that filtration, softening, and chlorination are processes used to "make" safe, softened, and clear water. After solving the problem, the wells were switched, and the problems returned. This indicated that the ions were at different concentrations in each well.

In chemistry, a "mole" is one of the seven basic units of measurement. The seven measuring units are mass, length, time, temperature, electrical charge, light intensity, and chemical quantity, or mole. (The first six units are gram, meter, second, Celsius degree, ampere, and candela).

In this water problem, someone had to do a calculation on the number of moles of sodium hypochlorite, and sodium permanganate to add per quantity of water treated based on the amount of iron and manganese (concentration) in each of the wells. You article mentioned some trial and error was used to solve this problem. The plant probably uses grams, or pounds to add to the water, or maybe a certain volume of the two chemicals in liquid form is added.

There may be people who read your article that did not understand the chemistry that you described, but they at least were made aware of the difficulty of processing raw water for a community water system and how important chemistry is in our lives at the community level. Thank you for conducting the necessary interviews, researching the facts, and writing such a detailed story.

As a district director of the Science Education Council of Ohio (SECO), I request permission to make copies and share your article with science colleagues that I meet throughout central Ohio. Publication, date, and author will be cited in the handout of your article.

Tom Tweedle Executive Director National Mole Day Foundation www.moleday.org

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