A company has a stack that emits a hazardous air pollutant. The ground mass concentration directly downwind of the plume sometimes exceeds the safe limit (call it cj,safe) and the Department of Environmental Protection (DEP) is requiring a correction to this situation. The company decides to look into building a taller stack, rather than investing in a more sophisticated and very expensive APCS. They hire you as a consultant to calculate how tall the new stack would have to be in order to satisfy DEP.

Required:
a. Generate an equation to determine the stack height hs required such that, for the reflecting ground case, the ground level concentration on the ground directly downwind (y = 0 and z = 0) does not exceed the safe level at any location along the ground.
b. Repeat for the absorbing ground case.
c. Discuss. Is this a good solution for the company’s problem? For the environment?