The earnings of the authority in excess of the amount required for the retirement of indebtedness or the accomplishment of the purposes stated in ORS 441.525 (Definitions for ORS 441) to 441.595 (Construction of ORS 441) shall not inure to the benefit of any person or body other than the municipality creating the authority. Upon dissolution of an authority, any assets remaining after provision for payment of the obligations and expenses of the authority shall become the assets of the municipality. [1973 c.153 §13; 1977 c.201 §6]