When uses in the C-1 Commercial District abut any residential district, the side setback shall be a minimum of 100 feet and the rear setback shall be a minimum of 150 feet. Adequate screening, as determined by the Planning Board, shall be provided. In addition, a buffer area of at least 50 feet shall be provided along the boundary line of the residential district. Such buffer area shall contain screen plantings of trees, hedges, shrubs, etc., to provide a visual and sound buffer between the districts.