Technical Summary: Marathon Petroleum Class-Action Litigation Following 2023 Refinery Fire in Louisiana’s Cancer Alley
Incident Overview
On August 25, 2023, a major fire broke out at the Marathon Petroleum refinery in Garyville, Louisiana, located within the region known as “Cancer Alley.” The incident involved the ignition of a naphtha storage tank, resulting in the release of volatile organic compounds (VOCs), including benzene, toluene, ethylbenzene, and xylene (BTEX), as well as particulate matter (PM2.5 and PM10). The fire persisted for approximately 72 hours, necessitating the evacuation of over 10,000 residents within a two-mile radius, as mandated by the St. John the Baptist Parish Office of Emergency Preparedness.
Emissions and Exposure
- Air Monitoring: Real-time air quality monitoring conducted by the Louisiana Department of Environmental Quality (LDEQ) detected benzene concentrations exceeding the EPA’s acute exposure guideline levels (AEGLs) for several hours post-incident. Peak benzene readings reached 0.15 ppm (parts per million), surpassing the AEGL-1 threshold of 0.10 ppm for sensitive populations.
- Chemical Inventory: The refinery’s Risk Management Plan (RMP) filed with the EPA lists annual throughput of over 500,000 barrels per day, with on-site storage of hazardous chemicals including hydrogen sulfide, sulfur dioxide, and ammonia.
- Health Impact: Following the event, local hospitals reported a 30% increase in emergency room visits for respiratory symptoms, consistent with acute exposure to refinery emissions. Residents also reported dermal irritation, headaches, and anxiety, which are recognized symptoms of VOC exposure.
Legal and Regulatory Context
- Class-Action Allegations: Plaintiffs allege violations of the Clean Air Act (CAA), Emergency Planning and Community Right-to-Know Act (EPCRA), and state-level environmental statutes. The asbestos claim cites negligence, failure to implement adequate emergency response protocols, and insufficient community notification as required under 40 CFR Part 355 (Emergency Planning and Notification).
- Environmental Justice: Cancer Alley is characterized by a disproportionate burden of industrial pollution on predominantly low-income and minority communities. According to EPA EJSCREEN data, the area’s cancer risk from air toxics is in the 95th percentile nationally. The region contains over 200 petrochemical facilities, and studies have documented cancer incidence rates up to 700 cases per 100,000 residents—significantly above the national average of 442 per 100,000.
Technical and Policy Implications
- Root Cause Analysis: Preliminary investigations suggest the fire was precipitated by a failure in the tank’s vapor recovery system, leading to over-pressurization and subsequent ignition. The U.S. Chemical Safety and Hazard Investigation Board (CSB) has launched a formal inquiry.
- Regulatory Response: In the aftermath, LDEQ issued a Notice of Potential Violation (NOPV) to Marathon Petroleum, and the EPA has called for enhanced Risk Management Program audits. Advocacy groups are demanding:
- Continuous fenceline air monitoring with public data access,
- Mandatory community notification systems,
- Comprehensive health impact assessments,
- Stricter enforcement of National Emission Standards for Hazardous Air Pollutants (NESHAPs).
- Precedent and Broader Impact: The outcome of this litigation may influence future enforcement of environmental justice provisions under Title VI of the Civil Rights Act and the Biden Administration’s Justice40 Initiative, which aims to direct 40% of federal environmental investments to disadvantaged communities.
Conclusion
The 2023 Marathon Petroleum refinery fire and subsequent class-action lawsuit underscore the intersection of industrial risk, regulatory oversight, and environmental justice in Cancer Alley. The case is poised to set important legal and technical precedents for emergency response, community right-to-know, and corporate accountability in high-risk industrial corridors.
