The amount of a loan under this part shall not exceed an amount equal to the Federal share of the estimated cost of construction or modernization under the project. Where a loan and a grant are made under this part with respect to the same project, the aggregate amount of such loan and such grant shall not exceed an amount equal to the Federal share of the estimated cost of construction or modernization under the project. Each loan shall bear interest at the rate arrived at by adding one-quarter of 1 per centum per annum to the rate which the Secretary of the Treasury determines to be equal to the current average yield on all outstanding marketable obligations of the United States as of the last day of the month preceding the date the application for the loan is approved and by adjusting the result so obtained to the nearest one-eighth of 1 per centum. Each loan made under this part shall mature not more than forty years after the date on which such loan is made, except that nothing in this part shall prohibit the payment of all or part of the loan at any time prior to the maturity date. In addition to the terms and conditions provided for, each loan under this part shall be made subject to such terms, conditions, and covenants relating to repayment of principal, payment of interest, and other matters as may be agreed upon by the applicant and the Surgeon General.

The Surgeon General may enter into agreements modifying any of the terms and conditions of a loan made under this part whenever he determines such action is necessary to protect the financial interest of the United States.

If, at any time before a loan for a project has been repaid in full, any of the events specified in clause (a) or clause (b) of section 291i 1 of this title occurs with respect to such project, the unpaid balance of the loan shall become immediately due and payable by the applicant, and any transferee of the facility shall be liable to the United States for such repayment.