(a) The following persons shall be parties to a certification proceeding under this Article: (b) The following persons may intervene in a certification proceeding under this Article if a petition to intervene is filed with the Commission within 100 days of the filing of the application and the petition is subsequently granted:(1) Any State department, municipality, or county entitled to notice under G.S. 62-102(b);(2) Any person whose land will be crossed by the proposed line;(3) Any other person who can show a substantial interest in the certification proceeding.