By Dan Molinski 



  Valero Energy Corp. reported the release of volatile organic compounds on Wednesday after a so-called floating roof atop a storage tank dropped into the liquids below it. 


   "The floating roof of the storage tank partially sunk into the liquid contents," the refinery said in a statement to the Texas Commission on Environmental Quality. "The material was transferred to another floating roof storage tank." 


   The refinery said the incident happened Wednesday afternoon and would be resolved by Thursday afternoon. Valero's 293,000-barrel-a-day Corpus Christi refinery has an east and west plant, and this incident happened at the east plant. 


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