Is the city of Concord affected? thanks
Unlikely. The refinery is to the north of Concord, and the prevaailing winds are from the west. I don't think that this was a big deal at all-- I just spoke with a friend who lives much closer and downwind than I, and she didn't notice anything wrong at all.
All I noticed was a period of time during which the air smelled a little like a 'home permanent'.