The corporation shall be a nonprofit corporation and no part of its net earnings remaining after payment of its expenses shall inure to the benefit of any individual, firm or corporation, except that in the event the board of directors of the corporation shall determine that sufficient provision has been made for the full payment of the expenses, bonds, and other obligations of the corporation, then any net earnings of the corporation thereafter accruing shall be paid to the municipality with respect to which the corporation was organized; provided, that nothing herein contained shall prevent the board of directors from transferring all or any part of its properties in accordance with the terms of any lease, sale contract, loan agreement, mortgage or deed of trust entered into by the corporation.