What Happens After You Flush?

Interesting viral vid by SciShow as he explains what happens after you've peed and pooped (his words not ours). 
He starts off with 'The Big Stink' of 1858 in the Thames River of London. What happens after 'we've done our business' has gone a long way and in fact, the water you just drank may well have been a part of someone’s urine just weeks ago, as he explains...