Meriwether, Cam Elliott, Dennis B. George, and V. Dean Adams.  "The Duck River Utility Commission (DRUC) draws water from Normandy Reservoir and provides approximately 4 MGD of finished water to the cities of Tullahoma and Manchester, Tennessee.  Due to a history of water quality complaints, an investigation of the DRUC water treatment system was initiated.  

"During the first half of the year, the water contains alkalinity and calcium concentrations of 25 to 35 mg-CaCo3/L.  As a result, the water treated by the plant is moderately corrosive.  Corrosivity of the finished water is aggravated by high chlorine levels in the distribution system.  Lime application, in conjunction with the addition of CO2 and soda ash, was evaluated for stabilization of the DRUC product water.  

"During late summer, reducing conditions in the reservoir cause solubilization of iron and manganese which are transported to the middle water intake.  Potassium permanganate treatment reduces iron below the recommended level of 0.30 mg/L; however, manganese in the finished water is frequently greater than the recommended 0.05 mg/L standard.  Failure of the plant to properly treat manganese was due, in part, to inadequate determination of manganese in the laboratory.  The P.A.N. low-range manganese test was evaluated and implemented in the DRUC lab."

(Text used by permission of Dr. Dennis George, an author of the document.)