Wash. Rev. Code § 70A.216.090
After January 1, 1992, it is unlawful for any person, firm, corporation, municipal corporation, or other governmental subdivision or agency to operate a solid waste incineration or landfill facility unless the operators are duly certified by the director under this chapter or any lawful rule or order of the department. It is unlawful for any person to perform the duties of an operator without being duly certified under this chapter. The department shall adopt rules that allow the owner or operator of a landfill or solid waste incineration facility to request a variance from this requirement under emergency conditions. The department may impose such conditions as may be necessary to protect human health and the environment during the term of the variance.
RCW 70A.216.090