; of which $46,977,000 shall remain available until September 30, 2020, and of which $2,000,000 shall remain available until September 30, 2023, for environmental compliance and restoration: Provided , That such amount is designated by the Congress as being for an emergency requirement pursuant to section 251(b)(2)(A)(i) of the Balanced Budget and Emergency Deficit Control Act of 1985. PROCUREMENT, CONSTRUCTION, AND IMPROVEMENTS For an additional amount for Procurement, Construction, and Improvements for necessary expenses related to the consequences of Hurricanes Michael, Florence, and Lane, Tropical Storm Gordon, and Typhoon Mangkhut, $476,755,000, to remain available until September 30, 2023: Provided , That such amount is designated by the Congress as being for an emergency requirement pursuant to section 251(b)(2)(A)(i) of the Balanced Budget and Emergency Deficit Control Act of 1985. GENERAL PROVISIONS—THIS TITLE 501. (a) In General The Federal share of assistance provided for DR–4336–PR, DR–4339–PR, DR–4340–USVI and DR–4335–USVI under sections 403, 406, and 407 of the Robert T. Stafford Disaster Relief and Emergency Assistance Act ( 42 U.S.C. 5170b and 5173) shall be 100 percent of the eligible costs under such sections. (b) Applicability The Federal share provided by subsection (a) shall apply to disaster assistance applied for before, on, or after the date of enactment of this Act. 502. The Administrator of the Federal Emergency Management Agency shall provide assistance, pursuant to section 428 of the Robert T. Stafford Disaster Relief and Emergency Assistance Act ( 42 U.S.C. 5121 et seq.), for critical services as defined in section 406 of the Robert T. Stafford Disaster Relief and Emergency Assistance Act for the duration of the recovery for incidents DR–4404, DR–4396, and DR–4398 to— (1) replace or restore the function of a facility or system to industry standards without regard to the pre-disaster condition of the facility or system