The food-stall plan has hand gel but no usable sink. What should I ask the organiser?

I checked the school fete's food-stall setup and found that the nearby handwashing sink was out of use. The organiser pointed to a bottle of hand gel and said, "We've covered hygiene."

I had volunteered to serve food, not to redesign the site. Still, I do not want to treat a bottle on the counter as the complete answer. [CDC says soap-and-water handwashing is important for preventing norovirus and that hand sanitiser alone does not work well against it](https://www.cdc.gov/norovirus/prevention/index.html).

There is another sink inside the building, but I do not know whether stall volunteers can reach it during service, whether it has supplies, or who covers the stall while someone goes.

The organiser thinks I am creating a last-minute task after the layout has been printed. What would you ask them to confirm before agreeing that the stall is ready? I want a usable washing arrangement, not an argument about whether one bottle proves everyone has tried.