I'd say a couple hundred pounds.
I saw this immensely disgusting men's room photo on reddit yesterday, and wondered, as is the way on reddit: WTF? Or, as the poster inquired: How does this happen?
Thankfully, redditor negativekarma came to the rescue:
That urinal is lower then the others, so a slight obstruction caused the other urinals to back flow into a bag that was on it because it was out of order.
I was able to then complete the rest of my day with a clear head. Physics is a pisser.
Previously: play a guitar with your piss stream.
Source: reddit.com