Removal of unsafe or unlawful signs. The Zoning Administrator shall order the removal of any sign erected or maintained in violation of this Part 3. In the case of a permanent sign, 10 days' notice, in writing, shall be given to the owner of such a sign, or of the building, structure or premises on which such a sign is located, to remove the sign or to bring it into compliance with this Part 3. All portable or temporary signs, pennants, ribbons, streamers, spinners, strings of light bulbs or other similar or moving devices erected in violation of this Part 3 shall be removed immediately upon receipt of written notice from the Zoning Administrator. Upon failure to remove the sign or to comply with this notice within the time specified, the Zoning Administrator shall require the sign to be removed. The Zoning Administrator shall require the sign to be removed immediately and without notice if it reasonably appears that the condition of the sign is such as to present an immediate threat to the safety of the public. Any costs of removal incurred by the Town of Bel Air shall be assessed to the owner of the property on which such sign is located and may be collected in the manner of ordinary debt or in the manner of taxes, and such charges shall be a lien on the property. Notwithstanding the above, the owner of the sign may file an appeal, in writing, to the Board of Appeals within 30 days of the date of the violation notice.