It shall be the duty of the planning commission to periodically patrol within the city limits to determine and report upon whether or not a nuisance, as defined by Section 8.08.020, exists on any premises within the city. Whenever the planning commission finds that a nuisance, as defined by Section 8.08.020, exists on any premises within the city, it shall advise the property owner of the nuisance and direct him to abate the nuisance. The property owner shall be notified of the existence of the nuisance in writing by registered mail. The notification shall detail the violations and establish a reasonable abatement period, which, if not otherwise specified, shall be fifteen days. (Ord. 90-3, 1990; Ord. 89-7 (part), 1989; Ord. 4-86 § 5, 1986)