; and (C) repayment of the loan to commence not later than 5 years after disbursement. 5. Lines of credit (a) In General (1) Agreements Subject to paragraphs (2) through (4), the Assistant Secretary may enter into agreements to make available to one or more obligors lines of credit in the form of direct loans to be made by the Assistant Secretary at future dates on the occurrence of certain events for any project selected under section 3. (2) Use of proceeds The proceeds of a line of credit made available under this section shall be available to pay debt service on project obligations issued to finance eligible project costs, extraordinary repair and replacement costs, operation and maintenance expenses, and costs associated with unexpected Federal or State environmental restrictions. (3) Risk assessment (A) In general Except as provided in subparagraph (B), before entering into an agreement under this subsection, the Assistant Secretary, in consultation with the Director of the Office of Management and Budget and each rating agency providing a preliminary rating opinion letter under section 3(b)(2)(A), shall determine an appropriate capital reserve subsidy amount for each line of credit, taking into account the rating opinion letter. (B) Small projects Before entering into an agreement under this subsection to make available a line of credit for a small project, the Assistant Secretary, in consultation with the Director of the Office of Management and Budget, shall determine an appropriate capital reserve subsidy amount for each such line of credit, taking into account the alternative documentation provided under section 3(b)(2)(B) instead of preliminary rating opinion letters provided under section 3(b)(2)(A). (4) Investment-grade rating requirement The funding of a line of credit under this section shall be contingent on— (A) the senior obligations of the project receiving an investment-grade rating from 2 rating agencies