A well mixed sewage lagoon is to be constructed to process 100,000 gallons per day of raw sewage. The pollutant concentration in the raw sewage to be discharged into the lagoon is 200ppm. The organic matter in the sewage has been shown in a laboratory experiment to be degraded biologically according to first order kinetics. The reaction rate constant (decay coefficent) is 0.5d^-1. According to State Enviromental Protection Agency the concentration of the lagoon effluent must be below 2ppm. Determine the surface area of a 1m depth lagoon. Assume no other water losses or gains (evaporation, seepage, or rainfall) and that the lagoon is completely mixed.