An accurate emission inventory is key to the development of reliable cost estimates for air pollution controls and emission reduction strategies. Cost estimating algorithms that are used to develop "study" estimates for specific control technology costs rely on accurate descriptions of the emission sources (e.g. detailed stack parameter information). Therefore, studies to examine potential emission reduction scenarios and the associated costs, begin with an emission inventory to ensure that all major sources are included, together with all parameters needed to calculate the cost of controlling the emissions.