These come from the FDA Food Code, which nearly every state adopts. A health inspector checks for them on plan review and at inspection — regardless of your state:
Also required in most kitchens: a mop/service sink (cleaning-water disposal), mechanical exhaust hood (Type I over grease/smoke), adequate hot water, indirect waste/air gaps on food & warewashing equipment, and a grease interceptor where local plumbing code requires it.
Licensing authority: County health departments under WA Retail Food Code (WAC 246-215-09110); vehicle inspected by WA L&I. Regime: Local + statutory reciprocity.
County health departments are required by statute to provide reciprocity if the operator holds a permit from another WA health department. Vehicle also inspected and permitted by Dept. of Labor & Industries. Food Worker Card required, valid 2 yrs.
Mobile/food-truck reciprocity: YES - RCW 43.20.149 requires counties to provide reciprocity
New builds and remodels almost always require a plan review and a pre-opening inspection. Submit your equipment layout early — the sink count, hood, and hot-water sizing are the usual sticking points.
See restaurant-equipment dealers in Washington → — many do design + fabrication and know local plan-review requirements.