§ 153.24  NON-CONFORMING USES.
   (A)   Regulations not retroactive. The regulations prescribed by this subchapter shall not be construed to require the removal, lowering or other changes or alteration of any structure or tree not conforming to the regulations as of the effective date of Ord. 2, or otherwise interfere with the continuance of any non-conforming use. Nothing contained in this subchapter shall require any change in the construction, alteration or intended use of any structure the construction or alteration of which was begun prior to the effective date of Ord. 2 and is diligently prosecuted.
   (B)   Marking and lighting. Notwithstanding provisions of division (A) above, the owner of any non- conforming structure or tree is required to permit the installation, operation and maintenance of such markers and lights as shall be deemed necessary by the Joint Airport Zoning Board to indicate to the operators of aircraft in the vicinity of the airport, the presence of such airport hazards. Such markers and lights shall be installed, operated and maintained at the expense of the airport.
(2012 Code, § 14-75)  Penalty, see § 153.99