A 55% efficient, 1200-MW (106 kW) Catao-Puerto Rico power plant emits SO2 at the legally allowable rate of 0.72 lb SO2 per million BTU of heat into the plant. The stack has an effective height of 280 m. an anemometer on a 10-m pole measures 3.2 m/s of wind, & it is cloudy summer day. Predict the ground level concentration of SO2, 7 km directly downwind. For this coal-fired power plant, use Figure 7.50 to determine the distance downwind to reach the maximum SO2 concentration & find that concentration