Imagine you're on a submarine.
You're on watch, and filling the potable water tank from the evaporator.
But, it takes "forever" so you wander off to complete some other mundane, soul sucking task.
Then you realize, HOLY CRAP! I'm still filling the tank. OH CRAP OH CRAP OH CRAP!
Cause, all the tanks have overflows.
I'll give you a clue, you can't overflow a tank to the outside, because of water pressure.