Utilities. All utility distribution facilities (including, but not limited to electric, communication and cable television lines) installed in and for the purpose of supplying service to any mobilehome park shall be placed underground, except as follows:
Equipment appurtenant to underground facilities such as surface-mounted transformers, pedestal-mounted boxes and meter cabinets, and concealed ducts. The developer is responsible for complying with the requirements of this section, and shall make the necessary arrangements with the utility companies involved for the installation of said facilities. The planning commission may waive the requirements of this paragraph if topographical, soil, or any other conditions make underground installation of said facilities unreasonable or impractical;