National Hazards Vulnerability and the Remediation, Restoration and Revitalization of Contaminated Sites-1. Superfund

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.

Identification and risk prediction of potentially contaminated sites in the Yangtze River Delta

Identification and risk prediction of potentially contaminated sites (PCS) are crucial for the management of contaminated sites. However, the identification and risk prediction methods of PCS are lacking at a regional scale. Here, we established the fuzzy matching algorithm based on the site's name for identifying PCS in the Yangtze River Delta (YRD) from 2000 to 2020. The results showed that PCS in the YRD increased by over ten times, from 336 in 2000 to 4191 in 2020. Socio-economic and physical geography drive the growth of PCS and its spatiotemporal distribution, while the former has a more significant impact than the latter. We also presented a risk probability zoning strategy based on the source-pathway-receptor model, and proposed the patch-generating land-use simulation model to predict the risk probability of PCS in 2030. The results of risk probability zoning from 2000 to 2020 indicated that the local government of the YRD has started to pay attention to PCS management and risk control while developing social and economic. The results of risk prediction demonstrated that the proportion of low-risk probability pixels is 96.1% in 2030. Therefore, the planned indicator in the Action Plan on contaminated sites established by the State Council of China can be achieved in the YRD. Our experience in identifying and predicting PCS can inform how the local government worldwide manages PCS and tackles future challenges of achieving the ambition of site pollution control.

National Hazards Vulnerability and the Remediation, Restoration and Revitalization of Contaminated Sites-2. RCRA Sites

Natural hazards can be powerful mechanisms that impact the restoration of Resource Conservation and Recovery Act (RCRA) contaminated sites and the community revitalization associated with these sites. Release of hazardous materials following a natural hazard can impact communities associated with these sites by causing the release of hazardous or toxic materials. These releases can inhibit the restoration of the sites, thus altering the long-term sustainable community revitalization. Hazard-related contaminant releases in areas characterized by large populations can create problems equal to those posed by the original site clean-up. Similarly, natural hazards can enhance the probability of future issues associated with the renovated sites. This manuscript addresses the co-occurrence of 12 natural hazards (singly and in combination) at individual RCRA sites. The co-occurrence was determined by the co-location of exposure likelihoods determined from the Cumulative Resilience Screening Index (CRSI) and the site locations for RCRA facilities provided by Environmental Protection Agency. Results showed that several natural hazards were likely to occur at RCRA facilities and these occurrences should be included in management and policy evaluations of these sites.