Arsenic in drinking water sources in the Middle Gangetic Plains in Bihar: An assessment of the depth of wells to ensure safe water supply

Abstract

This study assesses the depth of tubewell and the associated concentration of arsenic (As) in drinking water within the arsenic-affected regions in Bihar, India. A survey of 935 tubewell from two As-contaminated blocks in Bihar were conducted to collect and test the water samples. The results demonstrate that As concentration is mainly found in shallow tubewells (14–49 m deep), which is the main source of drinking water in the region in deep tubewells (>49 m deep), have arsenic concentration < 50 μg/L. The analytical results by field test kits (FTK) revealed that the levels of As in around 61% of the drinking water sources were above 10 μg/L, 20.8% samples contained arsenic 51-<100 μg/L, 16.9% contained 101-<300 μg/L, and 5.03% of the samples contained arsenic between 300 and 500 μg/L. Iron test results showed that around 74.4% of the samples contained iron at more than the prescribed 500 μg/L level of WHO. The study also revealed a general lack of awareness about the drinking water contamination and its associated health impacts. Therefore, awareness through various channels among the affected stakeholders will be helpful for the households to change their water sources (Saha et al., 2019).