Question

A water treatment plant is utilizing its clearwell as the sole method of achieving Ct compliance for inactivation of giardia. The chlorine residual leaving the clearwell is 1.4 mg/L. For a 0.5 log inactivation of giardia at a water temperature of 5ºC and a treated water pH of 8.0, the Ct value from the tables is 38. If the peak flow rate is 8,000 gpm, and the clearwell baffling factor is 0.7, what is the minimum water depth required to meet Ct in a clearwell with an inside diameter of 66 feet assuming 4 hours?

Answer 1