A large power plant emits 1,500 kg SO2 per day into a neutral atmosphere with a wind speed of 4 m/s. A town is located 5 km away from the plant, 5 degrees east of the wind direction. If the effective stack height of the plant is 100 m, and the ground reflects the SO2 emission perfectly what is the SO2 concentration at a sampling point located 2 m above the ground in the town.