In general, the Air Pollution Control Division (APCD) recommends following U.S. Environmental Protection Agency (EPA) procedures to assemble emission inventories and estimate Prevention of Significant Deterioration (PSD) increment (the maximum allowable increase in concentration that is allowed to occur above a baseline concentration for a pollutant. The baseline concentration is defined for each pollutant).

Report on the independent investigation of allegations made by three CDPHE employees regarding non-enforcement of National Ambient Air Quality Standards. This report primarily focuses on allegations regarding the modeling analysis conducted for a specific permit application for the Cripple Creek & Victor Gold Mine (CC&V), including claims of falsified data, suppression of information, and a conflict of interest.