When looking at the festival world and their large scale hygiene setups, we might be able to pull these hand wash stations for registration areas, crew areas delegate areas, for the corporate worlds too.
In the below version from EPS, this allows for 40 people to hand wash. (However this was during a festival where people stood close to each other) I also have to add that this particular unit requires you to turn the taps on and off manually, however I'm sure that can be done with movement trackers to avoid having to touch material.
http://www.eps.net/de/event/produkte/sanitaersysteme/waschmodule/
During a quick search I haven't found too many large scale hand wash options in the UK, but thats mainly cause I am not up to date with the UK festival scene...
