The overall objective of this research is to identify locations where potable water may be found that can be used for drinking purposes.
Supervisor Name: Ms. Uzma Imran, Assistant Professor, USPCAS-W, MUET, Jamshoro
Groundwater is an important source of drinking water, especially in areas where surface water is scarce or where drinking water sources are contaminated, due to agricultural or industrial effluents. The community near Manchar Lake is one of such examples. This study explored the potential sites surrounding Manchar Lake where good quality groundwater can be obtained for drinking purpose. Vertical electrical sounding (VES) was conducted on twentyone sites in a shallow depth grid (5 x 5 km2), by adopting a Schlumberger electrode array configuration, with a maximum spacing of 300 m in the current electrode (AB/2) and 20 m in the potential electrode (MN/2). The data were collected using an ABEM terrameter SAS 4000. The quantitative interpretation was done, using the IX1D resistivity software. VES findings were verified by analyzing water samples collected from trial bores, made by the hand-percussion method at five sites out of twentyone sites. The trial bores were made up to 100 ft. in depth and soil and water samples were collected at an interval of approximately 10 ft. depth from all the trial bores.
The collected soil and water samples were analyzed for pH, electrical conductivity (EC), soil texture and total dissolved solids (TDS). In addition, groundwater samples were collected from 7 hand pumps in April and July 2016 and were analyzed for physical, chemical and microbiological parameters. The analysis of trial bores water showed the same results in terms of EC and TDS. The water samples parameters exceeded the World Health Organization (WHO) limits for EC (1,500 μS/cm) and TDS (1,000 ppm) at all trial bore sites, which proved that the results obtained from VES are valid. However, the pH of water samples collected from all trial bores was within the WHO limit. Whereas, the analysis of soil (pH, EC and soil texture) collected from trial bores showed that all soil samples were within the WHO limit for pH and EC. The data for soil texture was also in a good match with VES data.
The analysis of groundwater samples revealed that all groundwater samples collected from the seven locations in April and July 2016 exceeded the WHO limit for EC (1,500 μS/cm), TDS (1,000 ppm), hardness (500 ppm), and total coliforms (0 Cfu/mL). Overall, the quality of groundwater around Manchar Lake was not suitable for drinking, based on this study. Only two out of 21 VES sites showed good quality water. Trial bores should be made at these sites to confirm the quality of groundwater, so these sites can be used for drinking purposes. Similar kind of studies should be considered for deeper depths, by increasing the space between the current electrodes and by digging enough trial bores at deeper depths to validate VES findings. In addition, other parameters must be analyzed, which are necessary to determine water fitness for drinking purpose. Furthermore, the groundwater near the lake must be treated, before using it for drinking purposes. Also, there is a need to study the effect of lake water on the groundwater of the study area.