Section 74.4 - Designated representative(a) The provisions of subpart B of part 72 of this chapter shall apply to the designated representative of an opt-in source.(b) If a combustion or process source is located at the same source as one or more affected units, the combustion or process source shall have the same designated representative as the other affected units at the source.60 FR 17115, Apr. 4, 1995, as amended at 63 FR 18841, Apr. 16, 1998; 71 FR 25379 , Apr. 28, 2006