; (II) iron, steel, and the relevant manufactured goods are not produced in the United States in sufficient and reasonably available quantities and of a satisfactory quality; or (III) inclusion of iron, steel, and manufactured goods produced in the United States will increase the cost of an overall project by more than 25 percent. (iii) If the head of a Federal department or agency determines that it is necessary to waive the application of this subparagraph based on a finding under subparagraph (B), the head of the department or agency shall publish in the Federal Register a detailed written justification as to why the provision is being waived. (iv) This paragraph shall be applied in a manner consistent with United States obligations under international agreements. (B) Wage rate requirement The Secretary of Transportation and the Secretary of Energy shall require that each recipient of support under this section provide reasonable assurance that all laborers and mechanics employed in the performance of the project for which the assistance is provided, including those employed by contractors or subcontractors, will be paid wages at rates not less than those prevailing on similar work in the locality as determined by the Secretary of Labor in accordance with subchapter IV of chapter 31 of part A of subtitle II of title 40, United States Code (commonly referred to as the Davis-Bacon Act ). 6. Authorization of appropriations There is authorized to be appropriated— (1) for carrying out section 3, such sums as may be necessary, to be available until expended; (2) for carrying out section 4, such sums as may be necessary, to be available until expended; and (3) for carrying out section 5, such sums as may be necessary, to be available until expended.