Washington Revised Code Title 34. Administrative Law § 34.05.322. Scope of rule-making authority

For rules implementing statutes enacted after July 23, 1995, an agency may not rely solely on the section of law stating a statute's intent or purpose, or on the enabling provisions of the statute establishing the agency, or on any combination of such provisions, for its statutory authority to adopt the rule. An agency may use the statement of intent or purpose or the agency enabling provisions to interpret ambiguities in a statute's other provisions.