title: Sediment color tool for targeting arsenic-safe aquifers for the installation of shallow drinking water tubewells.
abstract: In rural Bangladesh, drinking water supply mostly comes from shallow hand tubewells installed manually by the local drillers, the main driving force in tubewell installation. This study was aimed at developing a sediment color tool on the basis of local driller's perception of sediment color, arsenic (As) concentration of tubewell waters and respective color of aquifer sediments. Laboratory analysis of 521 groundwater samples collected from 144 wells during 2009 to 2011 indicate that As concentrations in groundwater were generally higher in the black colored sediments with an average of 239 μg/L. All 39 wells producing water from red sediments provide safe water following the Bangladesh drinking water standard for As (50 μg/L) where mean and median values were less than the WHO guideline value of 10 μg/L. Observations for off-white sediments were also quite similar. White sediments were rare and seemed to be less important for well installations at shallow depths. A total of 2240 sediment samples were collected at intervals of 1.5m down to depths of 100 m at 15 locations spread over a 410 km(2) area in Matlab, Bangladesh and compared with the Munsell Color Chart with the purpose of direct comparison of sediment color in a consistent manner. All samples were assigned with Munsell Color and Munsell Code, which eventually led to identify 60 color shade varieties which were narrowed to four colors (black, white, off-white and red) as perceived and used by the local drillers. During the process of color grouping, participatory approach was considered taking the opinions of local drillers, technicians, and geologists into account. This simplified sediment color tool can be used conveniently during shallow tubewell installation and thus shows the potential for educating local drillers to target safe aquifers on the basis of the color characteristics of the sediments.
authors.affiliation: KTH-International Groundwater Arsenic Research Group, Department of Sustainable Development, Environmental Science and Engineering, KTH Royal Institute of Technology, Teknikringen 76, SE-100 44 Stockholm, Sweden; NGO-Forum for Public Health, 4-6/Block-E, Lalmatia, Dhaka 1207, Bangladesh. Electronic address: mohhos@kth.se.
authors.forename: Mohammed
authors.initials: M
authors.lastname: Hossain
authors.affiliation: KTH-International Groundwater Arsenic Research Group, Department of Sustainable Development, Environmental Science and Engineering, KTH Royal Institute of Technology, Teknikringen 76, SE-100 44 Stockholm, Sweden. Electronic address: prosun@kth.se.
authors.forename: Prosun
authors.initials: P
authors.lastname: Bhattacharya
authors.affiliation: Department of Earth and Environmental Sciences, University of Waterloo, Waterloo, ON N2L 3G1, Canada.
authors.forename: Shaun K
authors.initials: SK
authors.lastname: Frape
authors.affiliation: KTH-International Groundwater Arsenic Research Group, Department of Sustainable Development, Environmental Science and Engineering, KTH Royal Institute of Technology, Teknikringen 76, SE-100 44 Stockholm, Sweden.
authors.forename: Gunnar
authors.initials: G
authors.lastname: Jacks
authors.affiliation: NGO-Forum for Public Health, 4-6/Block-E, Lalmatia, Dhaka 1207, Bangladesh.
authors.forename: M Mainul
authors.initials: MM
authors.lastname: Islam
authors.affiliation: Department of Geology, University of Dhaka, Dhaka 1000, Bangladesh.
authors.forename: M Moklesur
authors.initials: MM
authors.lastname: Rahman
authors.affiliation: KTH-International Groundwater Arsenic Research Group, Department of Sustainable Development, Environmental Science and Engineering, KTH Royal Institute of Technology, Teknikringen 76, SE-100 44 Stockholm, Sweden; Soil and Water Environment, Ramböll Sweden AB, SE-104 62 Stockholm, Sweden.
authors.forename: Mattias
authors.initials: M
authors.lastname: von Brömssen
authors.affiliation: Department of Geology, University of Dhaka, Dhaka 1000, Bangladesh.
authors.forename: M Aziz
authors.initials: MA
authors.lastname: Hasan
authors.affiliation: Department of Geology, University of Dhaka, Dhaka 1000, Bangladesh.
authors.forename: Kazi Matin
authors.initials: KM
authors.lastname: Ahmed
mesh_terms: D001151:Arsenic / Q000032:analysis*; D001459:Bangladesh; D003116:Color; D060766:Drinking Water / Q000737:chemistry*; D004784:Environmental Monitoring / Q000379:methods*; D019015:Geologic Sediments / Q000737:chemistry* / Q000145:classification; D060587:Groundwater / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis*; D060986:Water Wells
chemical_list: D060766:Drinking Water; D014874:Water Pollutants, Chemical; D001151:Arsenic
keywords: Arsenic; Bangladesh; Local driller; Sediment color tool; Sustainable mitigation; Tubewell