QUANTITATIVE ASSESSMENT OF THE SOCIO-ECONOMIC FACTORS DRIVING TO DRINK ARSENIC CONTAMINATED GROUNDWATER IN SHARIATPUR DISTRICT OF BANGLADESH

Tectonically, the study area is located in Faridpur Trough of the Bengal Foredeep and comprises a thick accumulation of Tertiary sediments. Physiographically, the studied area lies within the Lower Gangetic Floodplain. Lithologic cross sections and hydrogeological 3D block diagrams revealed the presence of multiple aquifer systems in which thickness and depth vary spatially within short distances. Except for the Holocene and Plio-Pleistocene Dupi Tila Formations, others are at greater depth and so economically not a viable option for tubewell installation. Previous studies proposed the source of As in the shallow Holocene aquifer is Geologic in origin. A study carried out by khan et al (2013), reported a high level of As concentration in a large number of shallow tube wells in that area. For the present study, a questionnaire survey was carried out among 127 households to examine the socio-economic factors influencing the rural communities to drink arsenic contaminated water from the shallow aquifer using multivariate statistics and Bayesian forward propagation techniques. Factors such as willingness to pay (-0.47), installation cost (0.21), literacy level (-0.18), awareness (+0.27), and income level (-0.12) showed relatively strong correlations with drinking shallow aquifer water. Cluster analysis showed that households who are solely using shallow aquifer water were mostly grouped in cluster 1 whereas deep tubewell users in cluster 3. Cluster 2 mostly grouped the households who are collecting water from multiple sources including untreated surface water. Principal component analysis results showed that 64% of the variations of the data are related to differences in awareness, willingness to pay, and income level to get access to safe water sources. Among all of the factors considered for sensitivity analysis in the Bayesian network, literacy and income level were identified as the root factors that had the greatest significance on each functionality criteria based on Shannon’s entropy (entropy reduction: 0.0006 – 0.0127). Further detailed investigations need to be carried out to adequately categorize the key driving forces and to propose effective intervention strategies to increase the likelihood of drinking As safe water in that area.