Sulfur Dioxide and Volatile Organic Compound Exposure to a Community in Texas City, Texas Evaluated Using Aermod and Empirical Monitoring Data

Abstract

According to emissions data reported to the United States Environmental Protection Agency (USEPA) and the Texas Commission on Environmental Quality (TCEQ), the BP Products North America Inc. (BP) Texas City Refinery is the worst polluter of all the industries in Texas City and is one of the worst polluting refineries in the country. The facility has reported releasing substantial emissions of Sulfur Dioxide (SO2) and Volatile Organic Compounds (VOCs). Air dispersion modeling of the emissions from the facility can be used to assess contamination in the community surrounding the BP Texas City Refinery. In the present study, air dispersion modeling of SO2 and VOCs was performed using AERMOD, the EPA-preferred regulatory dispersion model, to determine the impact of BP’s contribution to local air pollution on residents of Texas City and La Marque. SO2 emissions reported to be released by the facility were modeled using AERMOD and it was determined that geographical locations inside this plume experienced ambient air concentrations of SO2 meeting or exceeding 50 micrograms per cubic meter (µg/m³) in 2009 and 2010. Data collected by six active SO2 air monitors located in Texas City support the air dispersion modeling results. Additional modeling was conducted for VOCs emitted by the facility in 2010. The AERMOD analysis of SO2 concentrations in and around the BP facility produced results consistent with data collected by the air monitoring network in Texas City. This confirms the accuracy of AERMOD’s estimations and its reliability as an emissions modeling tool. VOC concentrations available for analysis from the air monitoring network in Texas City are extremely limited in terms of the quantity of VOCs sampled for. This evidence affirms the ability of AERMOD to demonstrate comprehensive contaminant impacts that surpass the ability of the current air monitoring network.