Reactive transport modeling for supporting climate resilience at groundwater contamination sites
Name
hess-26-755-2022.pdf
Description
Published version
Size
5.57 MB
Format
Adobe PDF
Checksum (MD5)
1156f464d7d0b3573ef1dc41bc47ac6c
Author(s)
Xu, Zexuan
Serata, Rebecca
Wainwright, Haruko
Denham, Miles
Molins, Sergi
Gonzalez-Raymat, Hansell
Lipnikov, Konstantin
Moulton, J David
Eddy-Dilek, Carol
Date Issued
February 11, 2022
Journal
Hydrology and Earth System Sciences
Publisher
Copernicus GmbH
Citation
Xu, Z., Serata, R., Wainwright, H., Denham, M., Molins, S., Gonzalez-Raymat, H., Lipnikov, K., Moulton, J. D., and Eddy-Dilek, C.: Reactive transport modeling for supporting climate resilience at groundwater contamination sites, Hydrol. Earth Syst. Sci., 26, 755–773, https://doi.org/10.5194/hess-26-755-2022.
Version
Final published version
Abstract
Climate resilience is an emerging issue at contaminated sites and hazardous waste sites, since projected climate shifts (e.g., increased/decreased precipitation) and extreme events (e.g., flooding, drought) could affect ongoing remediation or closure strategies. In this study, we develop a reactive transport model (Amanzi) for radionuclides (uranium, tritium, and others) and evaluate how different scenarios under climate change will influence the contaminant plume conditions and groundwater well concentrations. We demonstrate our approach using a two-dimensional (2D) reactive transport model for the Savannah River Site F-Area, including mineral reaction and sorption processes. Different recharge scenarios are considered by perturbing the infiltration rate from the base case as well as considering cap-failure and climate projection scenarios. We also evaluate the uranium and nitrate concentration ratios between scenarios and the base case to isolate the sorption effects with changing recharge rates. The modeling results indicate that the competing effects of dilution and remobilization significantly influence pH, thus changing the sorption of uranium. At the maximum concentration on the breakthrough curve, higher aqueous uranium concentration implies that sorption is reduced with lower pH due to remobilization. To better evaluate the climate change impacts in the future, we develop the workflow to include the downscaled CMIP5 (Coupled Model Intercomparison Project) climate projection data in the reactive transport model and evaluate how residual contamination evolves through 2100 under four climate Representative Concentration Pathway (RCP) scenarios. The integration of climate modeling data and hydrogeochemistry models enables us to quantify the climate change impacts, assess which impacts need to be planned for, and therefore assist climate resiliency efforts and help guide site management.
MIT Department
Massachusetts Institute of Technology. Department of Nuclear Science and Engineering
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Creative Commons Attribution
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DOI of Published Version
https://doi.org/10.5194/hess-26-755-2022
