Whenever the building official determines that a nuisance described in Section 13.16.240 exists, he shall deliver to the owner of the land upon which the nuisance has been determined by him to exist a written notice informing the owner of the determination that such nuisance exists. The notice shall state that unless the owner abates the nuisance within a time, following completion of service of the notice, therein stated, determined by the building official to be a reasonable time to accomplish such abatement, but not less than two weeks, or within such time files a notice of appeal with the clerk of the city council, the building official will abate the nuisance. It shall also state that the cost of such abatement may be added to the county assessment roll as a lien on the real property or placed on the unsecured tax roll. (Prior code § 7784)