By Dan Molinski 



  Valero Energy Corp. on Wednesday reported a leak and emissions inside the tank farm portion of its refinery in Corpus Christi, Texas. 


  "A material that appears to be slop oil was observed on the soil. The source of this material has not yet been determined," the refinery said in a statement to the Texas Commission on Environmental Quality. " The material is being removed from this location using vacuum trucks." 


  It said the emissions, including 200 pounds of benzyne, began Wednesday late-morning and was expected to last about five hours. 


  Valero's 293,000-barrel-a-day Corpus Christi refinery includes both an east and west plant. This incident happened at the east plant. 


  Write to Dan Molinski at dan.molinski@wsj.com