A pipe containing an ultimate (carbonaceous) BOD of 2300 mg/L flows into a stream at 1 cubic meter per minute. The stream has a flow rate of 13.8 cubic meters per minute and an ultimate BOD of 10 mg/L. Assuming a BOD reaction rate constant of -0.4/day, what will be the the BOD remaining in the stream after the combined flow has traveled for 2 days?
Remaining BOD after 2 days = [BOD] mg/L