By letter dated October 24, 2006, Marisol Inc. (Marisol) notified EPA of a shipment of PCB waste generated by ExxonMobil Research and Engineering Company (ÂExxonMobilÂ) that was not identified as PCB on the manifest. EPA issued a Show Cause letter with a CAFO enclosed. The letter explained that the penalty sought could have been $6400.00, but the CAFO only sought the reduced penalty of $4800.00.