It is the purpose of the I-3 Multipurpose District to establish standards for and permit the location of varied uses in areas of the Borough where the impact on adjacent uses will be minimal. It also is the purpose of this district to recognize and afford maximum protection to industrial and office uses already in existence. All uses shall be in strict compliance with the performance standards of this chapter, and no uses of a heavy industrial nature or with the impacts or characteristics of a heavy industrial use are to be considered appropriate for this district.