Wash. Rev. Code § 82.98.030
If any chapter, section, subdivision of a section, paragraph, sentence, clause or word of this title for any reason shall be adjudged invalid, such judgment shall not affect, impair or invalidate the remainder of this title but shall be confined in its operation to the chapter, section, subdivision of a section, paragraph, sentence, clause or word of the title directly involved in the controversy in which such judgment shall have been rendered. If any tax imposed under this title shall be adjudged invalid as to any person, corporation, association or class of persons, corporations or associations included within the scope of the general language of this title such invalidity shall not affect the liability of any person, corporation, association or class of persons, corporations, or associations as to which such tax has not been adjudged invalid. It is hereby expressly declared that had any chapter, section, subdivision of a section, paragraph, sentence, clause, word or any person, corporation, association or class of persons, corporations or associations as to which this title is declared invalid been eliminated from the title at the time the same was considered the title would have nevertheless been enacted with such portions eliminated. This section shall not apply to chapter 82.44 RCW.
RCW 82.98.030
Severability-1967 ex.s. c 149: "If any phrase, clause, subsection or section of this act shall be declared unconstitutional or invalid by any court of competent jurisdiction, it shall be conclusively presumed that the legislature would have enacted this act without the phrase, clause, subsection or section so held unconstitutional or invalid and the remainder of the act shall not be affected as a result of said part being held unconstitutional or invalid." [ 1967 ex.s. c 149 s 64.]
Severability-1965 ex.s. c 173: "If any phrase, clause, subsection or section of this act shall be declared unconstitutional or invalid by any court of competent jurisdiction, it shall be conclusively presumed that the legislature would have enacted this act without the phrase, clause, subsection or section so held unconstitutional or invalid and the remainder of the act shall not be affected as a result of said part being held unconstitutional or invalid." [ 1965 ex.s. c 173 s 32.]
Severability-1965 ex.s. c 141: "If any provision of this act, or its application to any person or circumstance is held invalid, the remainder of the act, or the application of the provision to other persons or circumstances is not affected." [ 1965 ex.s. c 141 s 9.]
Severability-1961 ex.s. c 24: "If any provision of this act, or its application to any person or circumstance is held invalid, the remainder of the act, or the application of the provision to other persons or circumstances is not affected." [ 1961 ex.s. c 24 s 15.]
Severability-1961 ex.s. c 7: "If any provision of this act or the application thereof to any person, firm or corporation or circumstance is held invalid, in whole or in part, such invalidity shall not affect other provisions or applications of the act which can be given effect without the invalid provisions or application and to this end the provisions of this act are declared to be severable.
If any provision of this act shall be declared unconstitutional or ineffective in whole or in part by a court of competent jurisdiction then to the extent that it is unconstitutional or ineffective, such provisions shall not be enforced, nor shall such determination be deemed to invalidate the remaining provisions of this act." [ 1961 ex.s. c 7 s 23.]