Wash. Rev. Code § 70A.200.100
In communities where there is an established curbside service and where recycling service is available to businesses, a recycling program must be provided at every official gathering and at every sports facility by the vendors who sell beverages in single-use aluminum, glass, or plastic bottles or cans. A recycling program includes provision of receptacles or reverse vending machines, and provisions to transport and recycle the collected materials. Facility managers or event coordinators may choose to work with vendors to coordinate the recycling program. The recycling receptacles or reverse vending machines must be clearly marked, and must be provided for the aluminum, glass, or plastic bottles or cans that contain the beverages sold by the vendor.
RCW 70A.200.100