199—13.5 (479B) Objections. A person, including a governmental entity, whose rights or interests may be affected by the object of a petition may file a written objection. The written objection shall be filed with the secretary of the board not less than five days prior to date of hearing. The board may, for good cause shown, permit filing of objections less than five days prior to hearing, but in such event petitioner shall be granted a reasonable time to meet objections.