Abstract
Water resources, including groundwater and prominent rivers worldwide, are under duress because of excessive contaminant and nutrient loads. To help mitigate this problem, the United States Department of Energy (DOE) has supported research since the late 1980s to improve our fundamental knowledge of processes that could be used to help clean up challenging subsurface problems. Problems of interest have included subsurface radioactive waste, heavy metals, and metalloids (e.g. uranium, mercury, arsenic). Research efforts have provided insights into detailed groundwater biogeochemical process coupling and the resulting geochemical exports of metals and nutrients to surrounding environments. Recently, an increased focus has been placed on constraining the exchanges and fates of carbon and nitrogen within and across bedrock to canopy compartments of a watershed and in river-floodplain settings, because of their important role in driving biogeochemical interactions with contaminants and the potential of increased fluxes under changing precipitation regimes, including extreme events. While reviewing the extensive research that has been conducted at DOE's representative sites and testbeds (such as the Oyster Site in Virginia, Savannah River Site in South Carolina, Oak Ridge Reservation in Tennessee, Hanford in Washington, Nevada National Security Site in Nevada, Riverton in Wyoming, and Rifle and East River in Colorado), this review paper explores the nature and distribution of contaminants in the surface and shallow subsurface (i.e. the critical zone) and their interactions with carbon and nitrogen dynamics. We also describe state-of-the-art, scale-aware characterization approaches and models developed to predict contaminant fate and transport. The models take advantage of DOE leadership-class high-performance computers and are beginning to incorporate artificial intelligence approaches to tackle the extreme diversity of hydro-biogeochemical processes and measurements. Recognizing that the insights and capability developments are potentially transferable to many other sites, we also explore the scientific implications of these advances and recommend future research directions.
| Original language | English |
|---|---|
| Article number | 043004 |
| Journal | Environmental Research Letters |
| Volume | 17 |
| Issue number | 4 |
| DOIs | |
| State | Published - 2022 |
Funding
The work highlighted here was chosen because it was overwhelmingly supported by the DOE and would not have existed otherwise. However, the authors did not specifically require that each cited manuscript have a specific DOE funding source acknowledgment. The efforts of DD, CIS, BA, JB, SSH, PN, HMW, and KHW were supported by the Watershed Function Scientific Focus Area (SFA) funded by the US Department of Energy, Office of Science, Office of Biological and Environmental Research under Award Number DE-AC02-05CH11231. DD and CIS also acknowledge support from the ExaSheds Project at Lawrence Berkeley National Laboratory funded by the United States Department of Energy, Office of Science, Biological and Environmental Research under Contract No. DE-AC02-05CH11231. HMW also acknowledges support from the Department of Energy, Office of Environmental Management, ALTEMIS—Advanced Long-Term Environmental Monitoring Systems project. This research used resources of the National Energy Research Scientific Computing Center (NERSC), a United States Department of Energy Office of Science User Facility located at Lawrence Berkeley National Laboratory, operated under Contract No. DE-AC02-05CH11231. The efforts of MIB, DIK, KMK, and EJO were supported by the Wetlands Hydrobiogeochemistry Scientific Focus Area (SFA) at Argonne National Laboratory, which is supported by the Earth and Environmental System Science Program, Office of Biological and Environmental Research (BER), Office of Science, US Department of Energy (DOE), under Contract DE-AC02- 06CH11357. JB’s effort was supported by the SLAC Floodplain Hydro-Biogeochemistry SFA, funded by the US Department of Energy, Office of Biological and Environmental Research, Earth and Environmental Systems Sciences Division. SLAC National Accelerator Laboratory is supported by the US Department of Energy, Office of Science, Office of Basic Energy Sciences under Contract No. DE-AC02-76SF00515. The efforts of EP, SP, and SB were sponsored in part by the Office of Biological and Environmental Research within the Office of Science of the US Department of Energy (DOE), as part of the Hg Science Focus Area (Critical Interfaces SFA) and IDEAS-Watersheds projects at the Oak Ridge National Laboratory (ORNL). The DOE will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan ( http://energy.gov/downloads/doe-public-access-plan ). ORNL is managed by UT-Battelle, LLC under Contract No. DE-AC05-00OR22725 with DOE. XC and TS were supported by the United States Department of Energy, Office of Science, Office of Biological and Environmental Research, Environmental System Science (ESS) Program through the River Corridor Scientific Focus Area project at Pacific Northwest National Laboratory. MZ’s contribution was performed with funding from the Department of Energy, Office of Science, Biological and Environmental Research, Subsurface Biogeochemical Research program (SCW1053) and performed under the auspices of the US Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. We thank Diana Swantek (LBNL) and Adam Malin (ORNL) for assistance with preparing figures , , and (A). We express our gratitude to Dan Hawks (LBNL) for helping with technical editing. Finally, we thank the anonymous reviewer(s) for their insightful comment that helped improve the manuscript.
Keywords
- contaminant
- critical zone
- groundwater
- hot spots and hot moments
- reactive transport models
- redox
