Problem 9. A stream, with a flow rate of 1.0 MGD and with a BOD (a non conservative pollutant) concentration of 20.0 mg/L, flows into a pond with 5 million

gallons of water. That pond has a single stream outlet that flows into a second pond with 3 million gallons of water and a single outlet. The rate of decay of BOD is 0.3 day Assuming complete mixing within each pond find the BOD concentration leaving the first pond, and the concentration of BOD leaving the second pond. (Assume steady state)