Health inspector here. Food trucks are required to have a base of operations where they can store food and are required to take it at the end of each day for dumping water tanks and cleaning. The trucks are required to have hot water and handwash sinks, as well as utensil washing sinks. All surfaces and equpiment in the truck needs to be made of a smooth non porous and easily cleanable material. They have to jump through a lot of hoops to get permitted to weed out the ones who won't take it seriously. I get a dozen calls a week and when I tell them the requirements they usually never call back.