Landscape. Existing hills, trees and ground cover fronting along public roads or adjacent property shall be preserved, maintained and supplemented by selective cutting, transplanting and addition of new trees, shrubs and other ground cover for the purpose of screening and noise reduction. If, however, the existing topography and natural vegetation does not lend itself to any economically feasible supplement plan, the operation can, if properly landscaped with grass, trees and shrubs, grade back overburden around the perimeter of the excavation site to create a berm for the purpose of screening and noise reduction. No berm shall be constructed within 25 feet of property boundaries. The type and design of screening shall be approved by the Town Board after referring the proposal to the Monroe County Soil and Water Conservation District or the Town Conservation Board. Adequate maintenance approval of the landscape by the Town Engineer shall be required for all permit renewals.