Underwater leakage

Okay, so by underwater leakage, I'm referring the particle effect that gives the players a heads-up that there is lava or water on top of that block. I noticed this same effect when building underwater.
I was placing dirt blocks when I saw water droplet particles forming on the bottom of the block.

I first noticed this in version 1.7.2 and the picture was taken in 1.7.5