River Hygiene and your students, clients, comrades:
I've been guiding river trips a long time. It's the same in the States as here in Oz: people are proud of their rivers, love their rivers, want to believe they're clean and safe.
I've gotten cryptosporidium from drinking the Thomo... and giardia and norovirus from other rivers around the world. Trust me, you don't want it...
Noro actually thrives in cold water for days. We know horses in the high country have been found to have giardia. There's also e-coli and a bunch of other nasties to be aware of that can cause the "stomach flu". Symptoms?... bad cramps, diarrhoea, fever, sweating, shakes, totally yuck... for maybe a day-ish.
I've been on river journeys in Oz where the sanitation wasn't so hot, pun intended. Wash water was lukewarm to cold, not enough suds, used to the point of being rather "skanky" and not changed over. Rinse the same, or maybe no rinse at all. Hand wash with hand pump that every dirty hand touches, no air dry net for the dishes. I've mentioned it discreetly to other guides and instructors, who sometimes get a tad defensive about it. I get it: nobody wants to feel like some kid getting sick might've been their fault. Or that the Snowy or Mighty Mitta etc. might not be perfectly pristine. Totally understandable. Sometimes I've had other instructors say "Nobody's ever gotten sick on one of my trips!" Then I've pointed to one or more sick students right there in front of us. Often the next line is "It's the stomach flu, not something they ate or drank.". Again, read the linked article.
Current state of the art is that we're moving ("moving"... get it?) towards taking our poo out instead of digging long trench "cat-holes at every river camp. The same camps that'll be used the very next nights by the very next river crew. Better hand washing and dish washing might be the next progression. Can't wait for river season to start again!