Thank you, Alice. Very much interested!
I am still looking for an answer to my question: what density of population can safely and comfortably bury faeces individually, in rural (eg pasture, meadow, roadside and woodland) and peri-urban (marginal "waste" land) situations respectively? 
What is the population density at which it becomes safer to share a toilet - pit, chemical or plumbed in to drainage?
What is a safe, comfortable limit to the number of individuals or households sharing a toilet? (And what criteria should be used to assess this?)
Any evidence-based answers would be very welcome!

Hi everyone, 

In case it's of interest - sharing this blog that we published last week by Regan John, on discriminatory attitudes and policies that make it difficult for UK Travellers to access sanitation. 

Read the blog here: "Human rights, discrimination and sanitation: A precarious reality for Travellers" 

Thanks, 

Alice