; and (ii) for all eligible airports, the total amount of firefighting foam concentrate, in gallons. (B) Determination of grant amounts The Secretary shall make a grant to the sponsor of each eligible airport in an amount equal to the product of— (i) the amount of funds made available to carry out this section that remain available after the Secretary reserves the amount described in paragraph (1); and (ii) the ratio of the amount determined under subparagraph (A)(i) for such eligible airport to the amount determined under subparagraph (A)(ii). (c) Program requirements (1) In general The Secretary shall determine the eligibility of costs payable under the PFAS replacement program by taking into account all engineering, technical, and environmental protocols and generally accepted industry standards that are developed or established for approved fluorine-free firefighting foams. (2) Compliance with applicable law To be eligible for reimbursement under the program established under subsection (a), the sponsor of an eligible airport shall carry out all actions related to the acquisition, disposal, and transition to approved fluorine-free firefighting foams, including the cleaning and disposal of equipment, in full compliance with all applicable Federal laws in effect at the time of obligation of a grant under this section. (3) Federal share The Federal share of allowable costs under the PFAS replacement program shall be 100 percent. (d) Authorization of appropriations (1) In general There is authorized to be appropriated not more than $350,000,000 to carry out the PFAS replacement program. (2) Requirements Amounts made available to carry out the PFAS replacement program shall— (A) remain available for expenditure for a period of 5 fiscal years