A treatment plant discharges effluent with the following characteristics: 15cfs(ft3/s) 45mg/L BOD (ultimate BOD, which is used in the Streter-Phelps analysis) 2.9mg/L dissolved oxygen 20C k1=0.12d1 (for the waste and for the waste mixed with the river) The plant outfall mixes with a river with the following characteristics: river flow velocity =0.55ft/s river flow rate =120cfs river temperature =20C(DOsat at this temperature is 9.08mg/L) 4mg/L BOD 8.3mg/L dissolved oxygen k2=0.34d1 Calculate the critical dissolved oxygen deficit, and the distance downstream where it occurs. Would the dissolved oxygen concentration at that point endanger fish life