We're not on a septic tank but in the time we've been in this house (less than three years) the drains have been blocked at least four times. I say drainS plural but actually it's always related to the toilet my son's been using, & although he denies it, I know (from appallingly intimate knowledge of aforementioned blockages) that there are huge wads of toilet paper involved.
There's only the two of us in the house, & at a rough estimate I'd say he uses easily six or more rolls to my one. I've never actually done an accurate calculation.
This son is early 20s, mental health not good, substance overuse not good.......and always has an answer, usually that it's not my business how much toilet roll he uses per poo. Which - if it weren't causing an issue with our drains - might be fair (apart from the environmental & cost considerations). But it is a big blooming issue.
Now he says he can't use the bathroom that's less likely to clog cos it's nearer the main sewer because he says that loo is uncomfortable.
So. AIBU raising the subject? And/or how could I raise the subject more fairly/rationally so he might understand?