ABSTRACT
Groundwater inthe study area is mostly attributed to the Ca-HCO3 type, isanoxic (mean ORP: −176 mV) having high As concentrations(ranged from <10 to 537.7 μg/L) foundonly in shallow to medium depth (30 to 50 m) along with high iron (0.072 to 9.8 mg/L) and with relatively low Mn (0.149 to 3.38 mg/L). Sediment analysis showed As as almost depth-dependent and higher levels has been found between 10 m to 30 m, with a maximum of 14.2 mg/kg (Table 1). Sediments in the upper aquifer are mostly gray to dark-gray, whereas sediments in the deep aquifer are mostly yellowish-gray to brown. Moderate correlation between As and Fe suggests that As may be associated with iron-bearing minerals.
