- A 100m tall chimney stack emits hydrogen chloride (density = 1.64kg/m3) at a rate of 1m3/s. The plume initially rises a further 5m directly above the exit before being convected horizontally by a wind blowing at a speed of 10m/s under neutral atmospheric conditions. A small housing development commences at a location which is a distance of x = 1500m downwind of the stack and y = 500m from the center-line of the plume. a. What is the pollution concentration (kg/m3) at ground level at the start of the housing development? b. If the wind direction changed so that the plume axis pointed directly towards the housing development, what would be the new ground level concentration at the same location as before? (Assume that the wind speed and the rate of emission remain unchanged). c. Estimate the location in ground where the concentration of pollutant is maximum. . For the above question, (Q1), estimate the percentage change in the ground level concentration if i. The height of the chimney stack is raised by 10% ii. If the exit temperature and air temperature are is 30 OC, 25 OC. iii. If the emission rate is raised by 50% iv. If the atmosphere is extremely unstable. v. The receptor is located at 1000 m away in the downwind direction from the small housing development (question 1). the mart immortant phurical chemical and biological characteristics of Municinal