full cost
(3) (A) The term “full cost” means an annual rate as determined by the Secretary that shall amortize the expenditures for construction properly allocable to irrigation facilities in service, including all operation and maintenance deficits funded, less payments, over such periods as may be required under Federal reclamation law or applicable contract provisions, with interest on both accruing from October 12, 1982 , on costs outstanding at that date, or from the date incurred in the case of costs arising subsequent to October 12, 1982 : Provided, That operation, maintenance, and replacement charges required under Federal reclamation law, including this subchapter, shall be collected in addition to the full cost charge. (B) The interest rate used for expenditures made on or before October 12, 1982 , shall be determined by the Secretary of the Treasury on the basis of the weighted average yield of all interest bearing, marketable issues sold by the Treasury during the fiscal year in which the expenditures by the United States were made, but shall not be less than 7½ per centum per annum. (C) The interest rate used for expenditures made after October 12, 1982 , shall be determined by the Secretary of the Treasury on the basis of the arithmetic average of— (i) the rate as of the beginning of the fiscal year in which expenditures are made on the basis of the computed average interest rate payable by the Treasury upon its outstanding marketable public obligations which are neither due nor callable for redemption for fifteen years from the date of issuance; and (ii) the weighted average yield on all interest-bearing, marketable issues sold by the Treasury during the fiscal year preceding the fiscal year in which the expenditures are made.