Readily accessible drinking water is a chief factor that has an adverse impact on health and life expectancy of the population in the present scenario (Kumar et al., 2007; WHO, 2004). Arsenic (As) contamination in the groundwater of the central Gangetic plain was first reported in the year 2002; since then, a number of studies on the groundwater have been conducted by different researchers in this region. Severe health problems caused by naturally occurring As contamination in groundwater triggered extensive studies on arsenic distribution and mobilization in different domains worldwide. Identification of chemical and geological processes responsible for As contamination in the groundwater of the region might be useful to install new tubewells and may allow tapping As-free aquifers as easily available drinking water sources. Approximately 30–35 million people are estimated to be vulnerable of As contamination >50 ppb in Bangladesh and 6 million in West Bengal (Chakraborti et al., 2002; Mandal and Suzuki, 2002; Srivastava and Sharma, 2013). In Bihar state alone, located in the eastern part of the Gangetic plain, 0.9 million inhabitants from 15 districts are reported to be living in an As risk zone (Saha et al., 2009) thus posing a serious risk to the population at large.