Loans in an amount not exceeding ninety percent of project costs may be made by the Bank of North Dakota from the fund maintained pursuant to this chapter. Such loans must bear interest at a rate of two percent of the outstanding principal balance of the loan. In consideration of the making of a loan under this chapter, each borrower shall execute a contract with the department to operate the project in accordance with standards established under chapter 50-30. The contract must also provide that if the use of the project is discontinued or diverted to purposes other than those provided in the loan application without written consent of the department, the full amount of the loan provided under this chapter immediately becomes due and payable. The Bank of North Dakota may annually deduct, as a service fee for administering the loan fund maintained under this chapter, one-half of one percent of the principal balance of the outstanding loans from the fund.