An ocean outfall diffuser that discharges treated wastewater into the Pacific Ocean is 500m from a public beach. The wastewater contains 105 coliform bacteria per milliliter. The wastewater discharge flow rate is 0.3 m3/s. The coliform first order death rate in seawater is 0.3 per h. The current carries the wastewater plume toward the beach at a rate of 0.5 m/s. The ocean current may be approximated as a pipe carrying 600m3/s of seawater. Determine the coliform concentration at the beach. Assume that the current behaves as a plug flow reactor and that the wastewater is completely mixed in the current at the discharge point.