Flowing into the future. The Mills River Water Treatment Plant started pumping water into the Asheville-area system last month — the culmination of a decade-long effort to find a new, viable water source. To honor the occasion, the Regional Water Authority of Asheville, Buncombe and Henderson staged a grand opening on Nov. 22, recognizing all who helped make the plant possible and offering tours for the state-of-the-art facility.
Water Resources Director Tom Frederick (pictured above) led one tour, showing local residents how the new plant operates. Staffed by eight employees, the facility draws water from an intake pipe about a mile away, at the confluence of the Mills and French Broad rivers. First, the water flows into a large, rectangular outdoor tank, where giant “rakes” slowly agitate it to separate out large particles, Frederick said.
The water then gets pumped into a reservoir for primary settling. To show the next step, Frederick led his tour group down several flights of stairs into the depths of the facility. There, at the base of huge concrete tanks, machines whir and whiz and ping as the water gets mixed with dissolved ozone, which begins the process of “deactivating” any bacteria, cysts and viruses that were present in the raw river water. Staff can monitor the process via a number of digital readouts and pressure gauges — as well as tiny windows, reminiscent of old World War II submarines, that offer a view into the tanks themselves.
Another chemical process combines the remaining impurities with alum, caustic and polymer, which get sorted out by the flocculators. In other words, the treated water gets stirred until the suspended impurities sink to the bottom. Another dose of ozonation later, the water filters through gravel, granular activated carbon and sand, continued Frederick.
The plant crew can monitor the process from several stations in the facility, including the computer-control room, where monitors display a variety of up-to-the-second data on the 5 million gallons per day the Mills River plant treats, he remarked.
For the final touches, Frederick said — leading his tour group past big tanks of fluoride and chlorine — the water gets disinfected and its pH adjusted. Shortly thereafter, it gets pumped into the water system via big, blue, 24-inch transmission lines labeled “Finished water” (pictured right).