Wash. Admin. Code § 296-310-040
(1) A contractor who intends to transport employees must obtain liability insurance. The department shall require public liability and property damage insurance that provides coverage, for each single occurrence and for each vehicle used to transport employees, in the following minimum amounts:
[Statutory Authority: RCW 19.30.130. WSR 86-01-027 (Order 85-34), § 296-310-040, filed 12/11/85.]