TUBEWELL PLATFORM COLOR AS A TOOL FOR SCREENING ARSENIC AND MANGANESE IN SHALLOW DRINKING WATER WELLS: A STUDY FROM MATLAB, BANGLADESH

Presence of high level of arsenic (As) in groundwater is one of the major and adverse drinking water quality problems in many countries, especially in Southeast Asia. Bangladesh is one of the worse affected areas, where As contamination in the groundwater is considered as one of the key environmental disasters. Besides As, recently the presence of Mn in drinking water has also got attention due to its neurological effect on children. To ensure the supply of safe water, it is now essential to formulate a reliable safe drinking water management policy to reduce the health threat caused by drinking of water containing higher concentration of As and Mn. In this context, the development of a simple low cost technique for the determination of As and Mn in drinking water wells could be very much useful and worth in the relevant sector. The aim of this study was to evaluate the effectiveness of tubewell platform color as low-cost, quick and convenient screening tool for As and Mn contamination in water wells. The result obtained from a survey of 272 wells conducted in Matlab, southeast Bangladesh, shows strong correlation between red color stain on tubewell platform and As enriched water in the respective well water. Compared to WHO drinking water guideline values of 10 µg/L and Bangladesh drinking water standard (BDWS) of 50 µg/L certainties were observed 98.7% and 98.3% respectively. The sensitivity and efficiency was calculated 98% and 97% respectively for red-colored platform to screen the tubewells with As more than 10 µg/L. Similarly for cut-off value of 50 µg/L, both sensitivity and efficiency values were 98%.

This study suggests that red colored platform could be effectively used for primary identification of tubewells with elevated level of As and thus could prioritise sustainable As mitigation management in developing countries. Black color platform can be typically expected only in the case of high Mn and low Fe with usually low As. However, such observation was not available among the platforms surveyed in the study area. As a result it was not possible to test the platform color for screening Mn enriched water.