Watch out for people selling home water purifiers in the Salt Lake Valley.

That's the warning of Salt Lake City-County Department of Health officials, who caution that purifiers are being sold for treatment of water that just doesn't need treatment."Often those who sell home water treatment systems use fear to motivate sales," said Terry Sadler, a health department official. "Usually the argument for the purchase of home water treatment systems is that some chemical could or might be in drinking water. Reports about contaminated water in areas other than Salt Lake County are used to frighten if not terrify potential buyers."

But Sadler emphasized that the salesmen rarely (if ever) have any knowledge of the source or quality of the water that would be treated by their systems. It is even more unlikely that they would know the potential for that water to become contaminated, he said.

"Each source of water used by community water systems is tested on a regular basis for both bacterial contamination and chemicals and must meet strict standards," Sadler said. "Other safeguards that protect the quality of water delivered by community water systems include keeping sources of contamination away from watershed areas, wellheads and springs."

The health official said the department reviews plans for changes or additions to water systems, and there are regular inspections of water systems by health department personnel.

"Water treatment system salesmen sometimes intimate that nothing is being done by government agencies or community water system owners to protect public drinking water," Sadler said. "That is not true. They fail to mention that those people who know the most about Salt Lake Valley's water sources drink the water from those sources without concern."

Health department officials do not recommend home water treatment systems, and they advise those who are considering the purchase of such a home system to get as many facts as they can.

"Independent advice from health professionals and experts on water treatment should supplement careful quizzing of the salesmen of the system," Sadler recommended. "If the system being considered is very expensive, it would be a good idea to have the water to be treated analyzed by an independent laboratory for the contaminants that the system is intended to remove."

Sadler stressed, "Water from our public water supplies should not need further treatment. Any decision to treat drinking water should be based only on the demonstrated need for that treatment and not on something that might happen."