The authority 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 authority shall determine that sufficient provision has been made for the full payment of the expenses, bonds, and other obligations of the authority, then any net earnings of the authority thereafter accruing shall be paid to the municipality with respect to which the authority was organized; provided, that nothing contained in this section shall prevent the board of directors from transferring all or any part of its properties in accordance with the terms of any lease entered into by the authority.