Investigation of Groundwater Quality in Two Different Geological Conditions

The groundwater quality at two different geological conditions in Assam, one having hilly terrain (Tangla) and another flat plain (Guwahati), was taken up for investigating the portability of the water supply system. The study was carried out by investigating the water quality parameters, analysis of borehole and aquifer materials by hydrometer. The water samples obtained from the wells at 60.96 to 121.92 m below ground level were analyzed. The results from the test parameters suggest that it is freshly fed water into the ground at Tangla, the pH and electrical conductivity (EC) of the water sample ranged between 5.1and 7.6 and 51 to 170 µS/cm, respectively. At Guwahati, pH and EC were found to be 7.0–7.1 and 238–253 µS/cm, respectively. The alkalinity was found to be 0.07–3.91 mg/L whereas chloride was found to be 40–180 mg/L. The calcium and magnesium concentration are 28.2 mg/L and 14.4 mg/L and 9.3 to 21.2 mg/L and 9.8 to 26.5 mg/L at the two respective places. Aquifer characteristics obtained from borehole on sieving suggest that the soil samples (depth 1–17 m) have the highest fine particulars up to 6.9%. The water of the wells in Guwahati and Tangla was found within the permissible limit except for the iron concentration (1.29 mg/L) at Guwahati. The field and laboratory study evidence that water quality obtained from wells in two locations is portable with minimal aeration to remove iron at Guwahati and no treatment is needed at Tangla.