; (ii) shall include a rate covenant, coverage requirement, or similar security feature supporting the project obligations; and (iii) may have a lien on revenues described in subparagraph (A), subject to any lien securing project obligations. (D) Interest rate The interest rate on a secured loan under this section shall be not less than the yield on United States Treasury securities of a similar maturity to the maturity of the secured loan on the date of execution of the loan agreement. (E) Maturity date The final maturity date of a secured loan under this section shall be the earlier of— (i) the date that is 35 years after the date of substantial completion of the relevant project (as determined by the Secretary)