Following the adoption of this article, any use or structure which is situated within the boundaries of the Steep Slope Conservation District and which does not conform to the permitted uses specified by § 300-137 of this article shall become a nonconforming use or structure, regardless of its conformance to the district in which it is located without consideration of this article. The expansion or continuance of said nonconforming use or structure shall be governed by the requirements of Article III of this chapter. However, the Zoning Hearing Board shall also ensure that the standards contained in § 300-141 of this article are applied to the expansion or continuance of said nonconforming use or structure.