(1) There is specific statutory direction to the agency that authorizes the adoption of the rule;
(2) A federal waiver has been granted that authorizes the adoption of the rule;
(3) Local or special conditions exist in this state that warrant a different rule;
(4) The state rule has the effect of clarifying the federal rules, standards, procedures or requirements;
(5) The state rule achieves the goals of the federal and state law with the least impact on public and private resources; or
(6) There is no corresponding federal regulation. [1997 c.602 §2]