Sec. 23. (a) The entire assessment is payable in cash without interest not later than thirty (30) days after the approval of the assessment by the works board if an agreement has not been signed and filed under section 22 of this chapter.
(b) If the assessment is not paid when due, the total assessment becomes delinquent and bears interest at the rate prescribed by IC 6-1.1-37-9 per year from the date of the final acceptance of the completed system by the works board.