Service, loading, trash disposal areas, outdoor displays, material storage, transformers and mechanical equipment. All service, utility, delivery, loading and outdoor storage and trash disposal areas shall be screened from all residential districts, public streets, parking lot and pedestrian walkways. Screening shall be by the use offences, walls, berms, or a combination of these. Screening shall be installed and maintained at a height which effectively blocks the view, but shall not be less than six feet. The screening shall have exterior plantings at minimum intervals of 10 feet.