40 CFR §63.11409

1. (a)You must operate a capture system that collects the gases and fumes released during the operation of each emissions source listed in Table 1 of this subpart and conveys the collected gas stream to a particulate matter (PM) control device.
2. (b)You must not discharge to the atmosphere through any combination of stacks or other vents process gases from an emissions source listed in Table 1 of this subpart that contain PM in excess of the allowable process rate determined according to Equation 1 of this section (for an emissions source with a process rate of less than 30 tons per hour) or Equation 2 of this section (for an emissions source with a process rate of 30 tons per hour or greater). If more than one process vents to a common stack, the applicable emissions limit for the stack is the sum of allowable emissions calculated for each process using Equation 1 or 2 of this section, as applicable.