It is the purpose of this Article to limit the injurious impact of nonconforming uses and/or structures on other adjacent properties within a particular district and the community as a whole, while recognizing that alterations, reestablishments and extensions of nonconforming uses and/or structures may not be contrary to the public interest or the general purpose of this chapter when failure to allow such alteration, reestablishment or extension would itself lead to neighborhood or district deterioration. It is further the purpose of this Article to prescribe those standards which are to be applied by the borough in determining the reasonableness of a proposal to alter, reestablish or extend a nonconforming use. The following are regulations which shall apply to the alteration, reestablishment or extension of nonconforming uses.