If CEMS data or data from an alternative monitoring system approved by the Administrator under subsection (a) is not available for any affected unit during any period of a calendar year in which such data is required under this subchapter, and the owner or operator cannot provide information, satisfactory to the Administrator, on emissions during that period, the Administrator shall deem the unit to be operating in an uncontrolled manner during the entire period for which the data was not available and shall, by regulation which shall be issued not later than eighteen months after November 15, 1990, prescribe means to calculate emissions for that period. The owner or operator shall be liable for excess emissions fees and offsets under section
7651j of this title in accordance with such regulations. Any fee due and payable under this subsection shall not diminish the liability of the unit’s owner or operator for any fine, penalty, fee or assessment against the unit for the same violation under any other section of this chapter.