Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Targeting low-arsenic aquifers in Matlab Upazila, Southeastern Bangladesh
KTH, School of Architecture and the Built Environment (ABE), Land and Water Resources Engineering. (KTH-International Groundwater Arsenic Research Group)
Research and Evaluation Division, BRAC Centre, Dhaka.
KTH, School of Architecture and the Built Environment (ABE), Land and Water Resources Engineering. (KTH-International Groundwater Arsenic Research Group)ORCID iD: 0000-0003-4350-9950
Department of Geology, University of Dhaka.
Show others and affiliations
2007 (English)In: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 375, no 2-3, 121-132 p.Article in journal (Refereed) Published
Abstract [en]

Groundwater with high concentration of geogenic arsenic (As) occurs extensively in the Holocene alluvial aquifers of Bangladesh. Local drillers in Matlab Upazilla are constructing deeper tubewells than in the recent past, primarily because of low concentrations of dissolved Fe and As. Locally a thick layer of black to grey sediments overlies an oxidised unit of yellowish-grey to reddish-brown sediments. The correlation between the colour of both units and the groundwater redox conditions was investigated to provide an easy tool for targeting low-arsenic groundwater. Based on the sediment colour at the screen depths described by local drillers, 40 domestic shallow tubewells were selected for water sampling. Four colours were used to describe the sediments: black, white, off-white (buff) and red. Generally, the groundwater was anoxic and the As concentrations ranged from less than 5.2 to 355 mu g/L. Water derived from the black sediment is characterized by relatively higher concentrations of dissolved NH4+, DOC, Fe, P, As and by low Mn and SO42- concentrations. The off-white and red sediments had high concentration of Mn and low NH4+, DOC, Fe, P and As concentrations. The water abstracted from the black sediments indicated the most reducing environment, followed by white, off-white and red respectively. Three boreholes verified the driller's perception of the subsurface lithologic conditions. Discrepancies between the driller's and the research team description of the sediment colours were insignificant. This study shows that sediment colour is a reliable indicator of high and low-As concentrations and can be used by local drillers to target low-arsenic groundwater.

Place, publisher, year, edition, pages
2007. Vol. 375, no 2-3, 121-132 p.
Keyword [en]
Bangladesh; Geogenic arsenic; Groundwater; Local drillers; Sediment colour; Targeting safe aquifers
National Category
Oceanography, Hydrology, Water Resources
Identifiers
URN: urn:nbn:se:kth:diva-7089DOI: 10.1016/j.scitotenv.2006.06.028ISI: 000247354700002PubMedID: 17113133Scopus ID: 2-s2.0-34249057119OAI: oai:DiVA.org:kth-7089DiVA: diva2:11997
Note
QC 20100716. Uppdaterad från In press till Published 20100716. Tidigare titel: "Targeting low-arsenic aquifers in Matlab upazila, Southeastern Bangladesh: Science of the Total Environment"Available from: 2007-05-14 Created: 2007-05-14 Last updated: 2011-12-27Bibliographically approved
In thesis
1. Arsenic in tubewell water of Bangladesh and approaches for sustainable mitigation
Open this publication in new window or tab >>Arsenic in tubewell water of Bangladesh and approaches for sustainable mitigation
2007 (English)Doctoral thesis, comprehensive summary (Other scientific)
Abstract [en]

There is an urgent need for Bangladesh to identify the arsenic (As) contaminated tubewells (TWs) in order to assess the health risks and initiate appropriate mitigation measures. This involves testing water in millions of TWs and raising community awareness about the health problems related to chronic As exposure from drinking water, and providing alternative safe water option for the exposed population of the country. The use of spatial maps in a participatory context emerged as an important tool for an effective and rational distribution of alternative safe water options for the exposed population of the country. Field test kit offers the only practical tool available to screen all the TW water considering the time frame and financial resources of the country.

A comparison of the field test kit results and laboratory measurements by atomic absorption spectrometry (AAS) as “gold standard” for As in water of 12,532 TWs in Matlab upazila (sub-district) in Bangladesh, indicates that the field test kit correctly determined the status of 87% of the As levels compared to the Bangladesh Drinking Water Standard (BDWS) of 50 μg/L, and 91% of the World Health Organization (WHO) drinking water guideline value of 10 μg/L.

In order to identify the sustainable alternative safe water options, different type of safe water options were distributed in Sonargaon and Jhikargachha upazilas (sub-district) in 2001 and later revisited the options in 2004 to identify the sustainable ones. It was observed that community acceptability of the distributed options was not encouraging; less than 2% of the provided options were found to be in use. However, two new approaches emerged from people’s initiatives, which were making rapid and positive contributions to safe water coverage: switching to the existing As-safe TWs and reinstalling TWs at 50-100 m depths by looking at particular type of sediment colours.

A study was conducted in Matlab upazila to validate the concept of installation/reinstallation of TWs at certain depths, a new concept promoted by local drillers (masons). The study revealed that locally a thick layer of black to grey sediments overlies an oxidized unit of yellowish-grey to reddish-brown sediments. The correlation between the colour of both units and the groundwater redox conditions was investigated to provide an easy tool for targeting low-arsenic groundwater. The water abstracted from black sediments contained high amount of As concentration but the concentration decreased towards the yeallowish to red sediments. Three boreholes verified the driller's perception of the subsurface lithologic conditions. Discrepancies between the driller's and the research team description of the sediment colours were insignificant. This study shows that sediment colour is a reliable indicator of high and low As-concentrations in TW water and can be used by local drillers to install TW.

Lack of financial resources and identification of an appropriate distribution tools are some of the major obstacles to provide sustainable solution to the exposed population of the country. Spatial mapping exercise along with community participation can help maximize the safe water coverage of different alternative safe water options by reducing financial involvement. Combining people’s voice with that of spatial information gave better results and the method is already been proved useful in targeting non-served areas. Participatory Rural Appraisal (PRA) methods along with geographical information system (GIS) used in the study to obtain relevant information. Participants from different focus groups were asked to determine their ‘own priorities’ for spatial planning of alternative arsenic-safe water options. The study discusses community perspectives on demand-based safe water options and reveals the suitability of using participatory geographic information system (PGIS) technique to target non-served areas for rational distribution of safe water options.

Place, publisher, year, edition, pages
Stockholm: KTH, 2007. xvi, 28 p.
Series
Trita-LWR. PHD, ISSN 1650-8602 ; 2007:1033
Keyword
Tubewell; Arsenic; field test kit; groundwater; sediment colour; local drillers; safe aquifer; people’s initiatives; Participatory GIS (PGIS)
National Category
Oceanography, Hydrology, Water Resources
Identifiers
urn:nbn:se:kth:diva-4372 (URN)978-91-7178-668-5 (ISBN)
Public defence
2007-05-24, Sal V1, KTH, Teknikringen 76, Stockholm, 10:15
Opponent
Supervisors
Note
QC 20100716Available from: 2007-05-14 Created: 2007-05-14 Last updated: 2010-07-16Bibliographically approved
2. Hydrogeological and geochemical assessment of aquifer systems with geogenic arsenic in Southeastern Bangladesh: Targeting low arsenic aquifers for safe drinking water supplies in Matlab
Open this publication in new window or tab >>Hydrogeological and geochemical assessment of aquifer systems with geogenic arsenic in Southeastern Bangladesh: Targeting low arsenic aquifers for safe drinking water supplies in Matlab
2012 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Naturally occurring arsenic (As) in Holocene aquifers in Bangladesh have undermined a long success of supplying the population with safe drinking water. Arsenic is mobilised in reducing environments through reductive dissolution of Fe(III)-oxyhydroxides. Several studies have shown that many of the tested mitigation options have not been well accepted by the people. Instead, local drillers target presumed safe groundwater on the basis of the colour of the sediments. The overall objective of the study has thus been focussed on assessing the potential for local drillers to target As safe groundwater. The specific objectives have been to validate the correlation between aquifer sediment colours and groundwater chemical composition, characterize aqueous and solid phase geochemistry and dynamics of As mobility and to assess the risk for cross-contamination of As between aquifers in Daudkandi and Matlab Upazilas in SE-Bangladesh. In Matlab, drillings to a depth of 60 m revealed two distinct hydrostratigraphic units, a strongly reducing aquifer unit with black to grey sediments overlies a patchy sequence of weathered and oxidised white, yellowish-grey to reddish-brown sediment. The aquifers are separated by an impervious clay unit. The reducing aquifer is characterized by high concentrations of dissolved As, DOC, Fe and PO43--tot. On the other hand, the off-white and red sediments contain relatively higher concentrations of Mn and SO42- and low As. Groundwater chemistry correlates well with the colours of the aquifer sediments. Geochemical investigations indicate that secondary mineral phases control dissolved concentrations of Mn, Fe and PO43--tot. Dissolved As is influenced by the amount of Hfo, pH and PO43--tot as a competing ion. Laboratory studies suggest that oxidised sediments have a higher capacity to absorb As. Monitored hydraulic heads and groundwater modelling illustrate a complex aquifer system with three aquifers to a depth of 250 m. Groundwater modelling illustrate two groundwater flowsystems: i) a deeper regional predominantly horizontal flow system, and ii) a number of shallow local flow systems. It was confirmed that groundwater irrigation, locally, affects the hydraulic heads at deeper depths. The aquifer system is however fully recharged during the monsoon. Groundwater abstraction for drinking water purposes in rural areas poses little threat for cross-contamination. Installing irrigation- or high capacity drinking water supply wells at deeper depths is however strongly discouraged and assessing sustainability of targeted low-As aquifers remain a main concern. The knowledge gained here can be used for developing guidelines for installing safe wells at similar environments in other areas of Bangladesh.

Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology, 2012. xii, 46 p.
Series
Trita-LWR. PHD, ISSN 1650-8602 ; 1063
Keyword
Arsenic, Bangladesh, drinking water, groundwater, sustainability, geochemistry, hydrogeology, modelling
National Category
Oceanography, Hydrology, Water Resources Geochemistry Environmental Sciences
Identifiers
urn:nbn:se:kth:diva-53300 (URN)978-91-7501-214-8 (ISBN)
Public defence
2012-01-20, F3, Lindstedtsvägen 26, KTH, Stockholm, 14:00 (English)
Opponent
Supervisors
Note
QC 20111227Available from: 2011-12-27 Created: 2011-12-27 Last updated: 2011-12-27Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full textPubMedScopusScienceDirect

Authority records BETA

Bhattacharya, Prosun

Search in DiVA

By author/editor
von Brömssen, MattiasJakariya, Md.Bhattacharya, ProsunJonsson, LindaLundell, LeonidasJacks, Gunnar
By organisation
Land and Water Resources Engineering
In the same journal
Science of the Total Environment
Oceanography, Hydrology, Water Resources

Search outside of DiVA

GoogleGoogle Scholar

doi
pubmed
urn-nbn

Altmetric score

doi
pubmed
urn-nbn
Total: 215 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf