Within thirty (30) days after abatement of the violation, the owner of the property shall be notified by the city manager of the cost of abatement, including administrative costs. The property owner may file a written protest with the city manager objecting to the amount of the assessment within fifteen (15) days thereafter. If the amount due is not paid within a timely manner as determined by the decision of the city manager or by the expiration of the time in which to file an appeal, the charges shall be certified by the city clerk to the Dubuque County treasurer in the manner of a special assessment against the property and shall constitute a lien on the property for the amount of the assessment. (2007 Code § 44-305)