There is hereby authorized to be appropriated not to exceed $25,000,000 for each of the fiscal years 1982, 1983, 1984, 1985, and 1986 to carry out the pilot projects and demonstrations authorized by section 1682 of this title, the residue removal credits authorized by section 1683 of this title, and the other provisions of this subchapter: Provided, That not to exceed $2,500,000 of such amount may be appropriated for administrative expenses to carry out this subchapter for the period beginning October 1, 1981, and ending September 30, 1986. Such sums shall be in addition to those provided under other provisions of law and shall remain available until expended.