Baton Rouge, La.
Baton Rouge, the capital of Louisiana with a population of 227,017, sits on the banks of the Mississippi River. ExxonMobil's Baton Rouge refinery is the second-largest in the country and refines over a half-million barrels of crude a day.
Hugging the eastern shore of the riverbank, the refinery was recently blamed in a report funded by the EPA for releasing 18.5 million pounds of accidental pollution between 2005 and 2008. In that period, there were 456 accidents reported at ExxonMobil's refinery alone, releasing 3.4 million pounds and 35,610 gallons of pollution into the air, river and surrounding neighborhoods.