They ChemTool explosion/fire decision to allow it to burn out was made to keep water runoff from polluting ground water and the Rock River which was less than 1/4 mile away up the hill. The home I built and lived in for 30 years before moving to Buffalo is 10 miles west. The video shows the smoke drifting south directly south over Rockton Towards Rockford Illinois. This area is right at the Illinois/Wisconsin border about 2 miles west of Interstate 90. The immediate area was evacuated.