The owner or operator of any unit or process source subject to the requirements of sections  7651b, 7651c, 7651d, 7651e, 7651f or 7651h of this title, or designated under section 7651i of this title, that emits sulfur dioxide or nitrogen oxides for any calendar year in excess of the unit’s emissions limitation requirement or, in the case of sulfur dioxide, of the allowances the owner or operator holds for use for the unit for that calendar year shall be liable for the payment of an excess emissions penalty, except where such emissions were authorized pursuant to section 7410(f) of this title. That penalty shall be calculated on the basis of the number of tons emitted in excess of the unit’s emissions limitation requirement or, in the case of sulfur dioxide, of the allowances the operator holds for use for the unit for that year, multiplied by $2,000. Any such penalty shall be due and payable without demand to the Administrator as provided in regulations to be issued by the Administrator by no later than eighteen months after November 15, 1990. Any such payment shall be deposited in the United States Treasury pursuant to the Miscellaneous Receipts Act. Any penalty due and payable under this section shall not diminish the liability of the unit’s owner or operator for any fine, penalty or assessment against the unit for the same violation under any other section of this chapter.
The owner or operator of any affected source that emits sulfur dioxide during any calendar year in excess of the unit’s emissions limitation requirement or of the allowances held for the unit for the calendar year, shall be liable to offset the excess emissions by an equal tonnage amount in the following calendar year, or such longer period as the Administrator may prescribe. The owner or operator of the source shall, within sixty days after the end of the year in which the excess emissions occured, submit to the Administrator, and to the State in which the source is located, a proposed plan to achieve the required offsets. Upon approval of the proposed plan by the Administrator, as submitted, modified or conditioned, the plan shall be deemed at  a condition of the operating permit for the unit without further review or revision of the permit. The Administrator shall also deduct allowances equal to the excess tonnage from those allocated for the source for the calendar year, or succeeding years during which offsets are required, following the year in which the excess emissions occurred.
It shall be unlawful for the owner or operator of any source liable for a penalty and offset under this section to fail (1) to pay the penalty under subsection (a), (2) to provide, and thereafter comply with, a compliance plan as required by subsection (b), or (3) to offset excess emissions as required by subsection (b).