Are there such thing is a flushing portable toilet?

Question

Are portable toilets enviormentally safe?

I had a dream about flushing portable toilets.

Answer 1

yes, the military uses them in Kuwait (at least on the bases I was at).  They are less "portable" than the standard portajohn, but they do have real toilets that flush and clean water (held in a separate tank from the waste) for handwashing.