Although the mix of industries appears to be diverse, their emission processes are often similar. For example, many industries use common unit operations such as industrial furnaces to generate steam for process use, whereas others use combustion sources, such as tunnel or rotary kilns.
A review of common repair and replacement practices for selected types of process facilities showed that such activities can vary considerably in frequency and cost4. Likewise, for a given emission source, such as a utility boiler, a wide range of pollution prevention and control options can vary in effectiveness and cost.
Emission sources, pollution prevention techniques, and pollution control technology are expected to change over time, and regulations such as the ones considered here can be part of the motivating factors for such change. However, the effects of regulations can vary greatly, depending on the specifics of the programs.