any Federal revenues from the Boulder Canyon and Parker-Davis projects which, after completion of repayment requirements of the said Boulder Canyon and Parker-Davis projects, are surplus, as determined by the Secretary, to the operation, maintenance, and replacement requirements of those projects:
Provided, however, That for the Boulder Canyon project commencing
June 1, 1987, and for the Parker-Davis project commencing
June 1, 2005, and until the end of the repayment period for the Central Arizona project described in
section 1521(a) of this title, the Secretary of Energy shall provide for surplus revenues by including the equivalent of 4½ mills per kilowatthour in the rates charged to purchasers in Arizona for application to the purposes specified in subsection (f) of this section and by including the equivalent 2½ mills per kilowatthour in the rates charged to purchasers in California and Nevada for application to the purposes of subsection (g) of this section as amended and supplemented:
Provided further, That after the repayment period for said Central Arizona project, the equivalent of 2½ mills per kilowatthour shall be included by the Secretary of Energy in the rates charged to purchasers in Arizona, California, and Nevada to provide revenues for application to the purposes of said subsection (g) of this section:
Provided, however, That the Secretary is authorized and directed to continue the in-lieu-of-tax payments to the States of Arizona and Nevada provided for in
section 618a(c) of this title so long as revenues accrue from the operation of the Boulder Canyon project; and