After determining assessable costs against a responsible party, the Jurisdiction Treasurer shall mail an itemized invoice to the responsible party at its last known address. Such invoice shall be due and payable within 30 days of the date of mailing and any amount unpaid after such date shall bear a late payment fee equal to 1% per month or fraction thereof that the amount due and any previously imposed late payment fee remains unpaid. If a responsible party shall appeal assessable costs pursuant to § 91.18, such costs, if upheld, in whole or part or in part, shall be due 30 days from the date of determination of the appeal any late payment fees shall apply thereafter.(Ord. 43, passed 4-14-03) Penalty, see § 10.99