The Delaware City Refinery has begun to refine Canadian tar sands, and has recently expanded the train offloading capabilities to accept tar sands by train at the refinery. Tar sands are considered to be the dirtiest petroleum on earth, and emit 3x the greenhouse gases of conventional oil.
With the ability to unload only 100 rail cars at a time, there is a backup waiting to enter the refinery. Norfolk Southern railroad has begun storing insulated and heated rail cars at the former Chrysler Assembly Plant in Newark, right next to a residential neighborhood and the UD campus.