An 'exclusive investigation' by the Sun has revealed that coffee chain Starbucks wastes 23million liters of water a day because staff around the world are told to run taps non-stop.
The front page of the Sun screams:
My pun idea:
STARBUCKS: THE WORLD'S LARGEST COFFEE DRAIN
('Drain' is meant to represent 'chain' in this pun. Hmmm....never a good sign when you have to explain a pun is it?!)