An abandoned sign is a sign that has been inactive for a period of at least one year. An abandoned sign shall be removed by the owner or lessee of the premises upon which the sign is located when the activity related to said sign is no longer conducted on the premises. If the owner or lessee fails to remove the sign, the Zoning Administrator shall give the owner 30 days’ written notice to remove it. Upon failure to comply with the notice, the Zoning Administrator may have the sign removed at the owner’s expense.