@article {2705,
	title = {Origin of Groundwater Arsenic in a Rural Pleistocene Aquifer in Bangladesh Depressurized by Distal Municipal Pumping},
	journal = {Water Resources Research},
	volume = {56},
	year = {2020},
	month = {Jan-07-2020},
	abstract = {Across South Asia, millions of villagers have reduced their exposure to high-arsenic (As) groundwater by switching to low-As wells. Isotopic tracers and flow modeling are used in this study to understand the groundwater flow system of a semi-confined aquifer of Pleistocene (>10 kyr) age in Bangladesh that is generally low in As but has been perturbed by massive pumping at a distance of about 25 km for the municipal water supply of Dhaka. A 10- to 15-m-thick clay aquitard caps much of the intermediate aquifer (>40- to 90-m depth) in the 3-km2 study area, with some interruptions by younger channel sand deposits indicative of river scouring. Hydraulic heads in the intermediate aquifer below the clay-capped areas are 1{\textendash}2 m lower than in the high-As shallow aquifer above the clay layer. In contrast, similar heads in the shallow and intermediate aquifer are observed where the clay layer is missing. The head distribution suggests a pattern of downward flow through interruptions in the aquitard and lateral advection from the sandy areas to the confined portion of the aquifer. The interpreted flow system is consistent with 3H-3He ages, stable isotope data, and groundwater flow modeling. Lateral flow could explain an association of elevated As with high methane concentrations within layers of gray sand below certain clay-capped portions of the Pleistocene aquifer. An influx of dissolved organic carbon from the clay layer itself leading to a reduction of initially orange sands has also likely contributed to the rise of As.},
	keywords = {Arsenic, Dhaka Bangladesh, groundwater pumping, modeling},
	issn = {0043-1397},
	doi = {10.1029/2020WR027178},
	url = {https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2020WR027178},
	author = {Mozumder, M. R. H. and Michael, H. A. and Mihajlov, I. and Khan, M. R. and Knappett, P. S. K. and Bostick, B. C. and Mailloux, B. J. and Ahmed, K. M. and Choudhury, I. and Koffman, T. and Ellis, T. and Whaley-Martin, K. and San Pedro, R. and Slater, G. and Stute, M. and Schlosser, P. and Geen, A.}
}
@article {493,
	title = {Geochemical and hydrogeological contrasts between shallow and deeper aquifers in two villages of Araihazar, Bangladesh: Implications for deeper aquifers as drinking water sources},
	journal = {Geochimica et Cosmochimica Acta},
	volume = {69},
	year = {2005},
	note = {id: 604; 999UZ Times Cited:59 Cited References Count:49},
	pages = {5203-5218},
	abstract = {Sediment and groundwater profiles were compared in two villages of Bangladesh to understand the geochemical and hydrogeological factors that regulate dissolved As concentrations in groundwater. In both villages, fine-grained sediment layers separate shallow aquifers ( 50 ka ago and a groundwater age of thousands of years. In the other village (Bay), the sediment is},
	issn = {0016-7037},
	doi = {10.1016/J.Gca.2005.06.001},
	author = {Zheng, Y. and van Geen, A. and Stute, M. and Dhar, R. and Mo, Z. and Cheng, Z. and Horneman, A. and Gavrieli, I. and Simpson, H. J. and Versteeg, R. and Steckler, M. and Grazioli-Venier, A. and Goodbred, S. and Shahnewaz, M. and Shamsudduha, M. and Hoque, M. A. and Ahmed, K. M.}
}
