It depends on whether the emergency generators qualify as Categorically Insignificant Emissions Units. If a facility has multiple generators or pumps, then aggregate horsepower rating in excess of 3,000 horsepower must be identified and included in the reporting [OAR 340-200-0020(23)(uu)].
(23)(uu) Emergency generators and pumps used only during loss of primary equipment or utility service due to circumstances beyond the reasonable control of the owner or operator, or to address a power emergency, provided that the aggregate horsepower rating of all stationary emergency generator and pump engines is not more than 3,000 horsepower. If the aggregate horsepower rating of all stationary emergency generator and pump engines is more than 3,000 horsepower, then no emergency generators and pumps at the source may be considered categorically insignificant;