The refinery where I work went to ULSD a few weeks ago. Most refineries started making the stuff June 1.

I can't speak for the whole industry, but the refinery where I'm at only makes one grade of diesel. The off-road diesel comes out of the same tanks as the on-road. Only difference is the dye which is added when it's loaded into the tanker trucks. It's not worth the trouble to have seperate tankage.