Requirements under existing rules governing the use of coal combustion products for structural fill that do not conflict with the provisions of this Subpart shall continue to apply to such projects. The Environmental Management Commission shall amend existing rules governing the use of coal combustion products for structural fill as necessary to implement the provisions of this Subpart. Such rules shall be exempt from the requirements of N.C. Gen. Stat. § 150B-19.3 (2014-122, s. 3(a).)