Pub. L. 92-514, tit. V, sec. 502

Sec. 502. The interest rate used for purposes of computing interest during construction and interest on the unpaid balance of the capital costs allocated to interest-bearing features of the project shall be determined by the Secretary of the Treasury, as of the beginning of the fiscal year in which construction is initiated, on the basis of the computed average interest rate payable by the Treasury upon its86 Stat. 970 outstanding marketable public obligations, which are neither due nor callable for redemption for fifteen years from date of issue.