3. Rear yard. The rear yard depth shall be at least twenty-five (25)feet
3. Rear yard. The rear yard depth shall be at least twenty-five (25)feet unless the rear yard abuts a railroad right-of-way; provided, however, that -120- where the lot abuts a Conservation-Recreation, Residential district or a lot containing a building used primarily for residential purposes, the rear yard shall not be less than fifty (50) feet. The Board of Appeals may waive one or more setback requirements upon a demonstration by the applicant that such waiver will further the goals of this