((a)) ** Definitions** For purposes of this subchapter—
((1)) ** Crude oil** The term “crude oil” includes crude oil condensates and natural gasoline.
((2)) ** Domestic crude oil** The term “domestic crude oil” means any crude oil produced from a well located in the United States.
((3)) ** Petroleum product** The term “petroleum product” includes crude oil.
((4)) ** United States**
((A)) ** In general** The term “United States” means the 50 States, the District of Columbia, the Commonwealth of Puerto Rico, any possession of the United States, the Commonwealth of the Northern Mariana Islands, and the Trust Territory of the Pacific Islands.
((B)) ** United States includes continental shelf areas** The principles of section 638 shall apply for purposes of the term “United States”.
((C)) ** United States includes foreign trade zones** The term “United States” includes any foreign trade zone of the United States.
((5)) ** United States refinery** The term “United States refinery” means any facility in the United States at which crude oil is refined.
((6)) ** Refineries which produce natural gasoline** In the case of any United States refinery which produces natural gasoline from natural gas, the gasoline so produced shall be treated as received at such refinery at the time so produced.
((7)) ** Premises** The term “premises” has the same meaning as when used for purposes of determining gross income from the property under section 613.
((8)) ** Barrel** The term “barrel” means 42 United States gallons.
((9)) ** Fractional part of barrel** In the case of a fraction of a barrel, the tax imposed by section 4611 shall be the same fraction of the amount of such tax imposed on a whole barrel.
((b)) ** Only 1 tax imposed with respect to any product** No tax shall be imposed by section 4611 with respect to any petroleum product if the person who would be liable for such tax establishes that a prior tax imposed by such section has been imposed with respect to such product.
((c)) ** Credit where crude oil returned to pipeline** Under regulations prescribed by the Secretary, if an operator of a United States refinery—
((1)) removes crude oil from a pipeline, and
((2)) returns a portion of such crude oil into a stream of other crude oil in the same pipeline,
((d)) ** Credit against portion of tax attributable to oil spill rate** There shall be allowed as a credit against so much of the tax imposed by section 4611 as is attributable to the Oil Spill Liability Trust Fund financing rate for any period an amount equal to the excess of—
((1)) the sum of—
((A)) the aggregate amounts paid by the taxpayer before , into the Deepwater Port Liability Trust Fund and the Offshore Oil Pollution Compensation Fund, and
((B)) the interest accrued on such amounts before such date, over
((2)) the amount of such payments taken into account under this subsection for all prior periods.
((e)) ** Income tax credit for unused payments into Trans-Alaska Pipeline Liability Fund**
((1)) ** In general** For purposes of section 38, the current year business credit shall include the credit determined under this subsection.
((2)) ** Determination of credit**
((A)) ** In general** The credit determined under this subsection for any taxable year is an amount equal to the aggregate credit which would be allowed to the taxpayer under subsection (d) for amounts paid into the Trans-Alaska Pipeline Liability Fund had the Oil Spill Liability Trust Fund financing rate not ceased to apply.
((B)) ** Limitation**
((i)) ** In general** The amount of the credit determined under this subsection for any taxable year with respect to any taxpayer shall not exceed the excess of—
((I)) the amount determined under clause (ii), over
((II)) the aggregate amount of the credit determined under this subsection for prior taxable years with respect to such taxpayer.
((ii)) ** Overall limitation** The amount determined under this clause with respect to any taxpayer is the excess of—
((I)) the aggregate amount of credit which would have been allowed under subsection (d) to the taxpayer for periods before the termination date specified in section 4611(f)(1), if amounts in the Trans-Alaska Pipeline Liability Fund which are actually transferred into the Oil Spill Liability Fund were transferred on , and the Oil Spill Liability Trust Fund financing rate did not terminate before such termination date, over
((II)) the aggregate amount of the credit allowed under subsection (d) to the taxpayer.
((3)) ** Cost of income tax credit borne by Trust Fund**
((A)) ** In general** The Secretary shall from time to time transfer from the Oil Spill Liability Trust Fund to the general fund of the Treasury amounts equal to the credits allowed by reason of this subsection.
((B)) ** Trust Fund balance may not be reduced below $1,000,000,000** Transfers may be made under subparagraph (A) only to the extent that the unobligated balance of the Oil Spill Liability Trust Fund exceeds $1,000,000,000. If any transfer is not made by reason of the preceding sentence, such transfer shall be made as soon as permitted under such sentence.
((4)) ** No carryback** No portion of the unused business credit for any taxable year which is attributable to the credit determined under this subsection may be carried to a taxable year beginning on or before the date of the enactment of this paragraph.
((f)) ** Disposition of revenues from Puerto Rico and the Virgin Islands** The provisions of subsections (a)(3) and (b)(3) of section 7652 shall not apply to any tax imposed by section 4611.