Upon completion of the construction, the council shall by resolution assess the benefit in terms of resulting costs to the county thereof, including actual cost of publication of notices, conduct of hearings, advertising for bids, engineering and all costs of financing incurred prior to the adoption of the resolution, to all land encompassed within the assessment district and shall levy such assessment thereon for the recovery of the benefit or portion thereof on either an ad valorem basis or on a per-acre basis on all of the land. Notice of such assessment shall be given by placing a true copy of the resolution in the United States mail addressed to the owner of the property as shall appear on the real property assessment records of the county giving opportunity for objections thereto within thirty (30) days of such deposit in the mail. Such assessment shall be final; provided, that any person aggrieved by such assessment may appeal the same to the circuit court for the county within thirty (30) days after the expiration of the time for objection. The proceeds of the assessment may be expended by the county council for or in aid of the purposes of this article or may be paid over to the commission for these purposes. In the event the assessments levied together with all capital contributions or other funds received by either the county or the commission for such extension exceed the original capital costs of the completed project, such excess funds shall be applied as credits toward payment of any unpaid assessments or as refunds in whole or in part of assessments fully paid, as applicable. (1971 L.M.C., ch. 1, § 1.)