(a) This subpart applies to your small municipal waste combustion unit if the unit meets the criteria in paragraphs (a)(1) and (a)(2) and the criteria in either paragraph (a)(3) or (a)(4) of this section:

(1) Your municipal waste combustion unit has the capacity to combust at least 35 tons per day of municipal solid waste or refuse-derived fuel but no more than 250 tons per day of municipal solid waste or refuse-derived fuel.

(2) Your municipal waste combustion unit commenced construction on or before August 30, 1999.

(3) Your municipal waste combustion unit is not regulated by an EPA approved and effective State or Tribal plan.

(4) Your municipal waste combustion unit is located in any State whose approved State plan is subsequently vacated in whole or in part, or the municipal waste combustion unit is located in Indian country if the approved tribal plan for that area is subsequently vacated in whole or in part.

(b) If you make a change to your municipal waste combustion unit that meets the definition of modification or reconstruction after June 6, 2001, your municipal waste combustion unit becomes subject to subpart AAAA of 40 CFR part 60 (New Source Performance Standards for Small Municipal Waste Combustion Units) and this subpart no longer applies to your unit.

(c) If you make physical or operational changes to your existing municipal waste combustion unit primarily to comply with this subpart, then subpart AAAA of 40 CFR part 60 (New Source Performance Standards for Small Municipal Waste Combustion Units) does not apply to your unit. Such changes do not constitute modifications or reconstructions under subpart AAAA of 40 CFR part 60.

(d) Upon approval of the State or tribal plan, this subpart will no longer apply, except for the provisions of this subpart that may have been incorporated by reference under the State or Tribal plan, or delegated to the State by the Administrator.