Wash. Rev. Code § 9A.16.120
(2) For the purposes of this section:
(c) "Reasonable grounds" include, but are not limited to:
(i) Exhibiting the effects of having consumed liquor, which means that a person has the odor of liquor on his or her breath, or that by speech, manner, appearance, behavior, lack of coordination, or otherwise exhibits that he or she has consumed liquor, and either:
(ii) Exhibiting the effects of having consumed an illegal drug, which means that a person by speech, manner, appearance, behavior, lack of coordination, or otherwise exhibits that he or she has consumed an illegal drug, and either:
[ 2003 c 219 s 1.]