Washing hands; washing bodies; washing clothes; waste; drinking.
I sometimes think about the contrivances of modern life, the strangely directed poverty we've chosen. Consider: it used to be, when you wanted water, you probably had access to ludicrous amounts of it. Perhaps terribly inconveniently, and it almost certainly wasn't known to be safe (although obviously most of it was) – our understanding of how to keep water safe simply didn't exist.
Washing in a river doesn't come close to using all the water of the river, and even if it did, the water is removed with hardly a chance to use it at all. The oceans were massive, but even lakes could easily outstrip human ability to meaningfully use them.
There's something clever and efficient about these essentialized uses. But there's another part of me worried about the relative poverty of that efficiency. What if there's real, complex, hard to detect value in that mega-abundance? Are we any better off now than before?
Of course, I believe quite strongly the answer is yes, we are. But there are going to be little pockets, little rounding errors, where human needs are too complicated to immediately notice they aren't being met. Deep social ties seem to be the obvious one. And those things might get essentialized away more and more.