; or (B) durable equipment need or impairment. (4) Oversight The Secretary shall establish procedures to enable the Secretary to oversee the construction, remodeling, or expansion of infrastructure or the purchase of durable equipment for which a loan guarantee is issued under this subsection. (5) Guarantee amount A loan guarantee issued under this subsection may not guarantee more than 80 percent of the principal amount of the loan. (6) Fees The Secretary shall establish fees with respect to loan guarantees under this subsection that, as determined by the Secretary— (A) are sufficient to cover all the administrative costs to the Federal Government for the operation of the program; (B) may be in the form of an application or transaction fee, or interest rate adjustment; and (C) may be based on the risk premium associated with the loan or loan guarantee, taking into consideration— (i) the price of Treasury obligations of a similar maturity; (ii) prevailing market conditions; (iii) the ability of the eligible infrastructure project to support the loan guarantee