An efficient and accurate method of pumping fluoride into a municipal water treatment distribution system.
Water fluoridation is the controlled addition of fluoride to a public water supply in order to reduce tooth decay as cited by the Center for Disease Control and Prevention. It is estimated that about two-thirds of the US population uses water that has been fluoridated from our municipalities. In stark contrast, only about 6% of the world’s population drinks fluoridated water.

The precise control of fluoride levels is paramount to health and safety of the public. Even with slightly above average recommended amounts of fluoride, though not considered dangerous, the results can lead to discoloration, unpleasant odor and taste of the city’s water supply. In the U.S. the optimal level of fluoridation ranges from 0.7 to 1.2 mg/L (milligrams per liter, equivalent to parts per million), according to the Center for Disease Control and Prevention. Depending on the average maximum daily air temperature; the optimal level is lower in warmer climates, where people drink more water, and is higher in cooler climates. The World Health Organization cautions that fluoride levels above 1.5 milligrams per liter leaves the risk for fluorosis. Consumption of water exceeding 10 mg/L fluoride has been shown to lead to pathological changes in bone structure, and skeletal fluorosis. Thus it is critical that the injection of fluoride be as precise and consistent as possible.

The WTP chief operator, Dusty Martin, of the Orange Water and Sewer Authority located in Chapel Hill, NC, was content with his present use of pulsating pumps for the fluoride system. However, since the Jones Ferry Road Water Treatment Plant serves as a model for state of the art improvements and is routinely used as an engineering maintenance example for the student engineers studying at the local university as well as at universities worldwide, Dusty was curious to compare a peristaltic pump in that same application.

The Jones Ferry Road Water Treatment Plant can treat up to 20 million gallons of raw water daily drawn from two nearby sources, University Lake and the Cane Creek Reservoir. Daily water use by the 70,000 people in the Carrboro-Chapel Hill area averages about 9 million gallons per day. The water treatment process encompasses several phases. The first phase is the addition of powdered carbon to the water supply from the lakes to improve the taste and control odor in the water. Secondly, the solid particles are separated from the water in settling tanks. Once that process is complete, the water is then filtered through layers of sand and anthracite coal. Lastly, chemicals are added for disinfection and public health. The chemicals include chlorine, ammonia, and fluoride. Although fluoride is not necessary, it is encouraged by the Board of Dental Health and approved by both the N.C. State Public Water Supply and the OWASA.