Sep 14, 2007

Making Clean Water Cleaner

Donald Curry only drinks water filtered through his refrigerator's water dispenser or from his pitcher. It's hard for him to trust the water when he knows the source of Victoria's water: 20,000 acre feet of surface water from the Guadalupe River with runoff from farms, chemicals and dead animals.

"Water is like a universal solvent. It'll pick up traces of whatever it's in contact with," said Alan Dennis, 71, of Hague Quality Water. "In cases like this, chlorine is your friend."

John Henderson, 78, retired, takes pride in the taste of his well water, ranking it well above city water. But residents with wells may experience more problems than those with city water. If animal waste gets in the well, it could cause an E. coli bacteria problem, Dennis said. His company installs most chlorination systems in the country.

With all the chemicals the city uses to treat the water, he advises some type of filtration system. Most homes in the city would do well with a reverse osmosis filter system, Dennis said.

Reverse osmosis can be another stopgap for safety in the city, said Wilber Cleveland, 61, consultant with Accurate Water. Surface water treatment plants may have problems from time to time.

But it shouldn't be used as a primary disinfectant, Cleveland warns. A primary disinfectant should be chlorine or ozone, which is 3,000 times more deadly than chlorine. Either that, or boil water.

The downside of using ozone is when injecting ozone, air must travel with it, Cleveland said. While some systems include ultraviolet light, Cleveland said it's not a filtration system in itself.

Particles clinging to bacteria may shield them from UV light, so Cleveland recommends filtering the water before and after it passes through UV light.

"UV doesn't kill anything," Cleveland said. "It rearranges DNA so [bacteria] can't reproduce."

E. coli or other bacteria may invade drinking water when floodwater gets into the sewage system, the septic tank is placed too close to a water well or the municipal system malfunctions, said Satish Desai, 64, owner of the Blue Spring Corporation in Port Lavaca.

As living organisms, E. coli bacteria multiply quickly, doubling in a couple hours, and old filters provide a breeding ground, Desai said.

Consumers who use a filtration system need to remember it is necessary to maintain it and change the filters at least once every three months, or the problem only worsens, Desai said.