Off-premises signs and signs on vacant property which exist on the effective date of the ordinance from which this section is derived shall remain until they are removed or fall into disrepair. A sign is in disrepair as determined by the building official at his discretion. When a sign is determined to be in a state of disrepair, the city shall notify the sign owner and the property owner of the existing condition. If the sign owner or property owner fails or refuses to comply, the city may remove the sign with all costs to be borne by the sign owner or property owner. The procedure to be followed by the city upon determination that a sign is in the state of disrepair shall be the same as the procedure established in section 34-66 et seq. relating to abatement of nuisances.