A644. The subpart DD threshold can be triggered at any given time during the year. If nameplate capacity of a subpart DD facility at the beginning of the year is less than the reporting threshold of 17,820 pounds and no changes are made to the operation during the year that increase capacity above the threshold, the facility does not need to report emissions. However, if a physical or operational change occurs during the year that causes the facility to exceed the reporting threshold, the facility must report emissions for the year in which the change occurs, beginning with the first month of the change and ending on December 31 of that year. For more information see 98.3(b)(3).