(a) Any outdoor advertising sign, display or device which is erected or maintained in violation of this chapter or any regulations lawfully adopted pursuant to this chapter is declared to be a public nuisance and may be forthwith removed, obliterated or abated by the Department, its employees or any peace officer of this State, when such violation is not corrected after 30 days' written notice of the violation to the owner of the sign, display or device or to the owner, lessee or occupant of the land upon which the sign, display or device is located. All costs incurred by the Department in abating a nuisance pursuant to this section shall be the responsibility of the owner of the sign, display or device and the Department shall have an action at law to recover such costs, as well as the expenses of suit. When any sign is damaged, or falls into disrepair to the extent that obvious repairs are needed, the owner shall be notified in writing by the Department to make all necessary repairs. If the sign is not repaired, rebuilt or removed within 30 days of the notification, the applicable sign permit shall lapse and become null and void.