Wash. Rev. Code § 70.230.090
The department shall establish and adopt such minimum standards and rules pertaining to the construction, maintenance, and operation of ambulatory surgical facilities and rescind, amend, or modify such rules, as are necessary in the public interest, and particularly for the establishment and maintenance of standards of patient care required for the safe and adequate care and treatment of patients. In establishing the format and content of these standards and rules, the department shall give consideration to maintaining consistency with such minimum standards and rules applicable to ambulatory surgical facilities in the survey standards of accrediting organizations or federal agencies that the secretary has determined to have substantially equivalent standards as the statutes and rules of this state.
RCW 70.230.090