A WWTP must disinfect its effluent before discharging to a near-by stream. The wastewater contains 4.5x105 fecal coliform CFUs per liter. The maximum permissible concentration that may be discharged is 2000 fecal coliform CFUs per liter. It is proposed that the pipe carrying the wastewater be used for the disinfection process. Determine the length of the pipe required if the linear velocity of the wastewater in the pipe is 0.75 m/s. Assume that the pipe behaves as a steady-state plug flow system and that the reaction rate constant for fecal coliform destruction is 0.23 min-1.