What is the parental imperative in that situation anyway? In this day and age?
Are you expected to oversee an evacuation of the pool and then arrange for drainage - then a complete eco-friendly disinfecting - then refilling?
I know if I was there and I saw something like that I would just shrug it off. Accidents happen. A little poop in a big chlorinated pool. Meh. I hate to break it to you but there is poop and pee in every public pool, nevermind lakes and rivers where there are entire multi-species ecosystems that never poop or pee anywhere else.
But I don't doubt there would be some uppity people ready to launch lawsuits for emotional distress.