Site plan review of nonconforming uses, buildings and structures in the Mixed-Use District and within the Historic Overlay. All nonconforming uses, buildings or structures may be continued in the Mixed-Use District and within the Historic Overlay, subject to all provisions of this article. In addition, all such uses, buildings or structures included in the above-referenced registry shall be submitted to the Planning Board for site plan review according to the procedures and standards of Article
VIII of this chapter within three years of the effective date of this chapter, or subsequent amendment of this chapter whereby a nonconformance is created, or at such time the owner and/or operator may request a building permit pursuant to Article
XII of this chapter. The purpose of site plan review is to propose such modifications to the use, building or structure which will reduce the nonconformance of said use, building or structure, while allowing the use to continue in operation. The Planning Board may require the modification of exterior nonconforming uses to more closely conform with the area and bulk regulations (Article
V), supplementary regulations (Article
VII) and Historic Overlay District regulations (Article
IX) of this chapter. The Planning Board may not require modification of buildings or structures except as part of normal maintenance and repair, or upon application for a building permit for uses in which site plan review is required according to Article
VIII of this chapter.