Chemical Fire at Marathon Refinery

<p>Marathon Petroleum Corporation’s facility in Garyville, Louisiana, is one of the largest refineries in the western hemisphere. Nearby residents of ‘fenceline’ communities, which directly border this and other facilities across Louisiana’s ‘Cancer Alley,’ are forced to breathe some of the most toxic air in the US; the cancer risk for local residents is seven times the U.S. national average.</p> <p>On 24 August 2023, a tank at the Marathon facility containing naphtha—a volatile hydrocarbon chemical mixture—began leaking, and 3.76 million kg (8.3 million lbs) of toxic flammable material was released, amounting to the second largest chemical spill in thirty years, according to the U.S. Environmental Protection Agency (EPA).</p> <p>For two days, residents of nearby communities and local reporters documented the growth and movement of a thick, black chemical plume; satellite images showed it stretching over 96km (60 miles). Yet even as residents reported severe health impacts, including several hospitalisations, state and corporate officials consistently claimed that there were no impacts beyond Marathon’s property line.</p> <p>With the Guardian, we interviewed seventeen residents of the fenceline communities that border Marathon’s property. Drawing from these testimonies and a wide range of open source materials, we constructed a 3D model of the refinery site and smoke plume. We also worked with collaborators at Imperial College London to develop a fluid dynamics simulation of the plume and its chemical components, mapping their movement and density within our model to evaluate the potential health impacts of the incident.</p> <p>To make visible the inconsistencies and gaps in authorities’ reporting, these different elements were then incorporated into a narrative platform designed to track and compare evidence of the incident’s development, accounts from residents, and the state’s response over time.</p>