Marathon refinery making tornado repairs Marathon refinery making tornado repairs Photo provided to WWLTV by viewer Stephanie Little Roberts -- A tornado caused damage to Marathon Petroleum's refinery in Garyville on Wednesday. Repairs are expected to be completed by mid-June, the company said Friday. Advocate staff report June 07, 2014 Comments Marathon Petroleum Corp.’s tornado-damaged Garyville refinery will be at a slightly reduced capacity until repairs are completed by mid-June, the company said Friday. Severe weather that spawned a 105 mph tornado struck the Garyville area on Wednesday. The refinery suffered damage to a cooling water system that serves part of the refinery, causing its No. 1 crude unit and other units to be taken offline. Based on an initial assessment of the damage and necessary repairs, the company said it expects the crude unit to be operational by mid-June. The company does not expect total refinery output to be significantly affected, projecting less than a 5 percent reduction to the company’s expected production for this quarter. “The exceptional response of Garyville’s employees and contractors, along with the support of the local and state emergency responders, is greatly appreciated,” president and CEO Gary R. Heminger said. “The workforce is to be commended for their outstanding efforts during the initial response phase.” Marathon Petroleum Corp. is the nation’s fourth-largest refiner, with a crude oil refining capacity of about 1.7 million barrels per day in its seven-refinery system. Marathon brand gasoline is sold through about 5,200 independently owned retail outlets across 18 states. In addition, Speedway LLC, an MPC subsidiary, owns and operates the nation’s fourth-largest convenience store chain, with about 1,480 convenience stores in nine states.