What is clear is that even if you put a sink outside the back door of your own store, from the illegal point of view, this behavior is not allowed. In other words, urban management personnel have the right to stop your behavior at any time. However, if the back door is a back alley, don't make the sink too big to affect other people's actions. Try to be active and get along with the neighborhood. If no one reflects it, and there is no major inspection, the urban management basically doesn't care about you.