‘Sec. 5. Rulemaking. The Department of Environmental Protection shall amend its rules in accordance with the Maine Revised Statutes, Title 5, chapter 375 to allow the retrofitting of single-walled underground storage tanks with secondary containment systems prior to the expiration of the tank manufacturer's warranty and to allow the upgrading of related piping. Rules adopted pursuant to this section are routine technical rules as defined in Title 5, chapter 375, subchapter 2-A.’