Former Premcor Refinery, Blue Island, Illinois : environmental investigations : progress update, Fall 2005 = Antigua Refineri a Premcor, Blue Island, Illinois : investigaciones ambientales : actualizacio n de progresos, octon o de 2005 /

Updates on-site environmental investigations by the PREMCOR Refining Group at the former Clark-Blue Island Refinery which began operations as the Great Lakes Refinery in the mid 1920s and continued operating at the Blue Island (Ill.) site until PREMCOR closed the refinery in 2001. Valero Energy Corporation purchased PREMCOR on Sept. 1, 2005.