A river has the following characteristics: flow rate = 1 m/s, dissolved oxygen concentration = 8.0 mg/L, temperature = 18C, BODs = 3.0 mg/L, reaeration constant at 20C = 0.5 d1, and a cross sectional area = 400 m (assume it is constant for the entire problem).A wastewater treatment plant discharges an effluent with the following characteristics: flow rate = 15000 m/d, dissolved oxygen = 2 mg/L, BODs =40 mg/L, temperature = 20C. The BOD decay rate constant is 0.2 d' at 20C. An industry illegally discharges 4000 m/d of biodegradable liquid wastes with BODs 600 mg/L, no dissolved oxygen, and a temperature = 50C at the same location of the wastewater treatment plant. Severe fish death has been reported, but the industry denies any wrongdoing. Can the industry be blamed for the fill kills? Find the dissolved oxygen concentration 3327 m downstream from the point of discharge with and without the industrial waste. Sketch (does not have to be exact) two sag curves on the same plot for the two scenarios (with and without the industrial waste).