The NAAQS for SO2 is maintained/protected by the PSD program, which establishes a maximum allowable increase in concentration of SO2 over a baseline concentration (PSD increment) in the atmosphere. 110 Sand Co. failed to obtain a PSD permit and operate with the best available control technology (BACT), which resulted in violations of the PSD increment and, ultimately, the NAAQS for SO2. Through this Order, 110 Sand Co. is required to increase their stack height from 60 ft. to 140 ft., which will decrease the concentration of SO2 in the atmosphere; thereby, preserving the PSD increment and maintaining the NAAQS for SO2 for 110 Sand Co.'s impact area. The concentration of SO2 in the atmosphere, based on emissions from 110 Sand Co. alone, will decrease significantly from 1,667 micrograms per cubic meter (ug/m3) to 205.1 ug/m3 based on a 24-hour average, which represents a 713% decrease in the SO2 concentration. Therefore, there is a direct environmental benefit for the source's modeled significant impact area.