Security of Deep Groundwater in the Coastal Bengal Basin Revealed by Tracers
Abstract Uncertainty persists regarding the vulnerability of deep groundwater across Asia's megadeltas. In the coastal Bengal Basin aquifer system, shallow groundwater (<100 m) commonly features high salinity or arsenic concentrations, and deep, better‐quality, groundwater supplies drinking...
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| Main Authors: | , , , , , , , , , |
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| Format: | Article |
| Language: | English |
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Wiley
2018-08-01
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| Series: | Geophysical Research Letters |
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| Online Access: | https://doi.org/10.1029/2018GL078640 |
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| _version_ | 1850034357198127104 |
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| author | D. J. Lapworth A. Zahid R. G. Taylor W. G. Burgess M. Shamsudduha K. M. Ahmed A. Mukherjee D. C. Gooddy D. Chatterjee A. M. MacDonald |
| author_facet | D. J. Lapworth A. Zahid R. G. Taylor W. G. Burgess M. Shamsudduha K. M. Ahmed A. Mukherjee D. C. Gooddy D. Chatterjee A. M. MacDonald |
| author_sort | D. J. Lapworth |
| collection | DOAJ |
| description | Abstract Uncertainty persists regarding the vulnerability of deep groundwater across Asia's megadeltas. In the coastal Bengal Basin aquifer system, shallow groundwater (<100 m) commonly features high salinity or arsenic concentrations, and deep, better‐quality, groundwater supplies drinking water to >80 million people. Here we report new radiocarbon evidence from a network of nine dedicated, multilevel monitoring wells, which indicates residence times of between 103 and 104 years for groundwater at depths >150 m. Modern groundwater detected in some deep abstraction wells using anthropogenic tracers (SF6, CFCs) is attributed to short circuiting of shallow groundwater within wells. Age‐depth profiles and hydrochemical data in monitoring wells confirm the regional resilience of deep groundwater to ingress of shallow contaminated groundwater. Our results are consistent with high regional anisotropy in the aquifer and support continued use of deep groundwater though the potential for leakage of shallow contaminated groundwater in deep abstraction wells requires careful monitoring. |
| format | Article |
| id | doaj-art-5e2bcda1632e4d7fb0e95190a69ab5ea |
| institution | DOAJ |
| issn | 0094-8276 1944-8007 |
| language | English |
| publishDate | 2018-08-01 |
| publisher | Wiley |
| record_format | Article |
| series | Geophysical Research Letters |
| spelling | doaj-art-5e2bcda1632e4d7fb0e95190a69ab5ea2025-08-20T02:57:52ZengWileyGeophysical Research Letters0094-82761944-80072018-08-0145168241825210.1029/2018GL078640Security of Deep Groundwater in the Coastal Bengal Basin Revealed by TracersD. J. Lapworth0A. Zahid1R. G. Taylor2W. G. Burgess3M. Shamsudduha4K. M. Ahmed5A. Mukherjee6D. C. Gooddy7D. Chatterjee8A. M. MacDonald9British Geological Survey Wallingford UKBangladesh Water Development Board Dhaka BangladeshDepartment of Geography University College London London UKDepartment of Earth Sciences University College London UKDepartment of Geography University College London London UKDepartment of Geology Dhaka University Dhaka BangladeshDepartment of Geology and Geophysics Indian Institute of Technology Kharagpur Kharagpur IndiaBritish Geological Survey Wallingford UKDepartment of Chemistry University of Kalyani Kalyani IndiaBritish Geological Survey Edinburgh UKAbstract Uncertainty persists regarding the vulnerability of deep groundwater across Asia's megadeltas. In the coastal Bengal Basin aquifer system, shallow groundwater (<100 m) commonly features high salinity or arsenic concentrations, and deep, better‐quality, groundwater supplies drinking water to >80 million people. Here we report new radiocarbon evidence from a network of nine dedicated, multilevel monitoring wells, which indicates residence times of between 103 and 104 years for groundwater at depths >150 m. Modern groundwater detected in some deep abstraction wells using anthropogenic tracers (SF6, CFCs) is attributed to short circuiting of shallow groundwater within wells. Age‐depth profiles and hydrochemical data in monitoring wells confirm the regional resilience of deep groundwater to ingress of shallow contaminated groundwater. Our results are consistent with high regional anisotropy in the aquifer and support continued use of deep groundwater though the potential for leakage of shallow contaminated groundwater in deep abstraction wells requires careful monitoring.https://doi.org/10.1029/2018GL078640Indo‐Gengeticgroundwatersecuritytracersresidence timesdeep groundwater |
| spellingShingle | D. J. Lapworth A. Zahid R. G. Taylor W. G. Burgess M. Shamsudduha K. M. Ahmed A. Mukherjee D. C. Gooddy D. Chatterjee A. M. MacDonald Security of Deep Groundwater in the Coastal Bengal Basin Revealed by Tracers Geophysical Research Letters Indo‐Gengetic groundwater security tracers residence times deep groundwater |
| title | Security of Deep Groundwater in the Coastal Bengal Basin Revealed by Tracers |
| title_full | Security of Deep Groundwater in the Coastal Bengal Basin Revealed by Tracers |
| title_fullStr | Security of Deep Groundwater in the Coastal Bengal Basin Revealed by Tracers |
| title_full_unstemmed | Security of Deep Groundwater in the Coastal Bengal Basin Revealed by Tracers |
| title_short | Security of Deep Groundwater in the Coastal Bengal Basin Revealed by Tracers |
| title_sort | security of deep groundwater in the coastal bengal basin revealed by tracers |
| topic | Indo‐Gengetic groundwater security tracers residence times deep groundwater |
| url | https://doi.org/10.1029/2018GL078640 |
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