(2) The charge shall be due and payable as soon as imposed and billed, and if not paid within 60 days after the billing date, the charge shall become delinquent.
(3) In case the sums received from the charges exceed the total cost of items for which the charges are imposed, the surplus shall be placed in the general fund of the district and used to pay cost of construction. Upon dissolution of the district, any amount of surplus remaining shall be prorated and refunded to the landowners who paid the charges. [Amended by 1991 c.459 §425c]