; and (3) not less than $3,000,000 shall be made available for two remaining projects under section 190 of the FAA Reauthorization Act of 2018 ( Public Law 115–254 ): Provided , That, notwithstanding subsection (j)(2) of section 190 of the FAA Reauthorization Act of 2018 ( Public Law 115–254 ), such grants shall be made available for conducting testing activities in support of studying the effectiveness of existing federally funded sound insulation in residential areas located within the 65 DNL noise contour of a large-hub airport that will facilitate future environmental mitigation projects in these areas: Provided further , That, with respect to a project funded under the previous proviso, the allowable project cost for such project shall be calculated without consideration of any costs that were previously paid by the Government: Provided further, That the Secretary may make discretionary grants to primary airports for airport-owned infrastructure required for the on-airport distribution or storage of sustainable aviation fuels that achieve at least a 50 percent reduction in lifecycle greenhouse gas emissions, using a methodology determined by the Secretary, including, but not limited to, on-airport construction or expansion of pipelines, rail lines and spurs, loading and off-loading facilities, blending facilities, and storage tanks: Provided further, That the Secretary may make discretionary grants with funds made available under this heading to primary or nonprimary airports for the acquisition or construction costs related to airport-owned, revenue-producing aeronautical fuel farms and fueling systems, including mobile systems, that the Secretary determines will promote the use of unleaded or sustainable aviation fuels on a non-exclusive basis: Provided further , That the Secretary may make discretionary grants for airport development improvements of primary runways, taxiways, and aprons necessary at a nonhub, small hub, medium hub, or large hub airport to increase operational resilience for the purpose of