Environmental Impacts of Hurricane Harvey on the Neches-Brakes Bayou River System in Beaumont, Texas.

Hurricane Harvey caused unprecedented floods across large regions of Southeast Texas resulting in several infrastructural issues. One of the notable failures was of a drinking water source pump in Beaumont, Texas, that necessitated the emergency use of a temporary pump intake station in the Neches River system. This study examines the environmental consequences of Harvey-induced flooding in the Neches River system by focusing on sensitive locations, including a Superfund site (International Creosoting, IC) and adjacent to the temporary pump intake. Post-Harvey water samples showed greater than two orders of magnitude increase in polycyclic aromatic hydrocarbons (PAH) about 3 weeks after Harvey (350-420 µg L-1 on September 22) at locations adjacent to IC and the temporary water pump intake, which by that time was no longer in use. The organic carbon normalized PAH measurements in the heavily contaminated water samples from both locations (~3% w/w) agreed well with surficial soil/sediment samples collected at the east bank adjacent to the IC site (0.7-5.2% w/w). Furthermore, molecular diagnostic ratios of select PAHs supported the contribution of PAHs from the IC site into the surface waters. PAH measurements were consistent with sediment resuspension by floodwaters that were initially diluted by large flows but became more significant as the flood subsided. Overall, our data showed that flooding can cause high levels of contamination weeks after the initial flooding event, with potential for cascading risks through mobilization of pollutants from source areas and impacts to critical water infrastructure systems.