A lake with 100 x 107 m2 of surface area is fed by a stream having 42 m3/s of flow with 2.0 mg/L phosphorus. Phosphorus is also entering the lake through an industrial wastewater treatment plant discharges at 1.2 m3/s containing 230 mg/L phosphorus. If the lake is well mixed and the phosphorus settling rate is 12 m/yr, estimate the steady-state phosphorus concentration in the lake. What level of phosphorus removal at the treatment plant would be required to keep the average phosphorus concentration in the lake below 0.30 mg/L