Pre-Existing Use. Any nonconforming use or building lawfully existing on December 17, 1979, or at the time of passage of any previous zoning ordinance of the Borough may be continued upon the lot or in the building so occupied, but nothing in this chapter shall validate or authorize any nonconforming use or structure which exists in violation of a previous zoning ordinance, unless such use or structure is specifically permitted and authorized by this chapter.

Destruction of Pre-Existing Building. Any nonconforming use or building existing on December 17, 1979, may be continued upon the lot or in the building so occupied in the mixed commercial, light industrial, heavy industrial, research distribution and waterfront recreational zones, even though the building may be destroyed and the building may be restored or repaired in the event of such destruction thereof.

Damage to Pre-Existing Building. Any nonconforming use or building existing on December 17, 1979, in the residential or commercial zones may be continued upon the lot or in the building so occupied, even though the building may be damaged; so long as the cost of the repairs to remedy such damaged area shall in no case exceed 50% of the appraised value, nor shall the building be enlarged unless the use therein is changed to a conforming use.

Change of Nonconforming Use. A nonconforming use, if once changed into conforming use, shall not be changed back again into nonconforming use.

Abandonment of Nonconforming Use. A nonconforming use which has been abandoned shall not be reestablished to a nonconforming use. Nonuse for a period of more than one year shall create a presumption of abandonment. Nonuse or abandonment shall be determined by the zoning board of adjustment.