An Investigation of Plume Response to Soil Vapor Extraction and Hypothetical Drum Failure

Soil vapor extraction (SVE) has been used at sites across the Department of Energy complex, including sites where legacy subsurface wastes represent a potential source of groundwater contamination. At Los Alamos National Laboratory (LANL), leakage from waste drums buried at an inactive chemical waste site has created a subsurface vapor plume of volatile organic compounds (VOCs). Soil vapor extraction operation in 2015 and rebound testing through 2017 were successful in reducing the plume’s mass and mitigating VOC migration toward the water table. However, the possibility that waste drums could fail and release VOCs could pose a challenge in the future. To explore the impacts of drum failure, as well as the capabilities of SVE remediation, we simulated hypothetical contaminant release scenarios and subsequent SVE remediation. Three-dimensional subsurface VOC behavior, including advection, diffusion, and plume interactions with topography, were simulated using the porous flow simulator Finite Element Heat and Mass Transfer. Simulations of future site conditions have allowed identification of “sentry” boreholes that can be monitored for early detection in case of drum failure. Sentry boreholes can also be used to set concentration thresholds above which SVE should be initiated. For the LANL site, simulations show that SVE can be started 3 yr following drum failure and remain a viable remediation tool. More broadly, the principles outlined in this work can be used to support remediation planning at other subsurface waste sites. Predictive models of future releases can be analyzed to set concentration threshold values, guide selection of sentry boreholes, and increase operational efficiency

Narco-Fish: Global fisheries and drug trafficking

This study analyses drug trafficking associated with fisheries around the globe. Records of vessel interdiction carried out between 2010 and 2017 suggest that the global trade of illicit drugs relies increasingly on fishing vessels. Fishery-based trafficking is growing. A key obstacle to understanding the scope of this problem is the limited data on activities that are intentionally obscured, such as drug trafficking. Using a Fermi estimation technique for determining unknown values from limited data, we analyse 292 known cases of fishing boats engaged in drug shipment between 2010 and 2017. Results suggest that drug shipment sizes per vessel are becoming smaller over time, even as the total flow of drugs is increasing. Counter-drug enforcement intensifies this effect, suggesting that drug trafficking networks adapt to interdiction efforts making use of smaller vessels to lower the risk of seizure. The use of fishing vessels in drug trans-shipment has tripled over the past 8 years to about 15% of the global retail value of illicit drugs. Small-scale fishers are at risk of turning to drug trade as an economic buffer against poverty, especially in contexts of mounting competition over declining fish stocks or strict marine conservation. At the same time, illicit capital flowing from the narcotics trade into fisheries may be driving over-capitalization of fisheries and unsustainable resource use, ultimately to the detriment of resource-dependent coastal communities and marine ecosystems. Future research is needed to better understand whether and how small-scale fishermen turn to drug trade to counter livelihood risks of various kinds