What the heck!
I have a 1998 S70 N/A with 90K miles.
At around 60K miles it developed a very slow coolant leak. I could never find the leak. At 85K I went to change the time belt and noticed a very small amount of coolant below the water pump. No evidence that it was coming from the weep hole. It looked like it was the water pump gasket. So during the timing belt change I changed the gasket on the water pump.
This seemed to fix the leak for a few thousand miles then the slow leak started again (every week or so I had to add coolant). Then after a couple more thousand miles the leak got big. A steady stream of coolant that looked like it was coming from the bottom of the water pump.
I pulled the pump off again and the gasket looked good. I put a new gasket and pump on and the leak was still there, not even diminished. It is very hard to see where this leak is coming from. It looks like it is coming out from between the plastic timing cover shroud and the block, directly below the water pump.

Could this leak be coming from somewhere else?
Could the lower water pump locating dowel be protruding to far and keeping the water pump from seating against the block all the way?

Has anyone seen a problem like this before?