I'm not exactly sure how to describe what is happening but.. I took some pictures.

http://imgur.com/a/v63M5

The in game shots I took to show the oddness going on with the particles. In the first in game shot there should be fire there from blowing up a mine. Some of the particles can be seen overlapping the rubble of the barrel to the left.

The second in game shot is of an area that I assume is on fire but only shows a few little spots with flames showing. The characters burn if I get them even close to bridge area. The invisible fire goes away after shooting the water barrels but the small fire bits stay.

Also of note is the water going through/over the ground off to the upper left.

I also think there are supposed to be shadows showing but I can't be sure what should and shouldn't be showing at this point.

DxDiag info here:
http://pastebin.com/9dCmeKJy