Class 1 permit modifications cover routine changes; class 2 modifications address common or frequently occurring changes needed to maintain a facility's capability to manage wastes safely or to conform with new regulatory requirements; class 3 modifications cover major changes that substantially alter the facility or its operations.
Over time a facility may need to modify a permit to improve equipment or make changes in response to new standards. Recognizing this, EPA established procedures early in the program for modifying permits. The Agency has now revised these procedures to provide more flexibility to both owners and operators of facilities and EPA to increase public involvement. Contact your state hazardous waste office for more information.