SPATIAL ANALYSIS OF GROUNDWATER SOURCES POTABILITY DURING WET SEASON IN THE MUNICIPALITY OF TANTANGAN, SOUTH COTABATO

The study was conducted to evaluate groundwater potability in the Municipality of Tantangan, South Cotabato through the Quantum Geographic Information System (QGIS). Seven samples were gathered, in which three of the sources were shallow wells (pitcher pumps), another three for springs, and one for a deep well. Different parameters such as water hardness, electrical conductivity, turbidity, total dissolved solids (TDS), total suspended solids (TSS), pH level, nitrate, mercury, phosphate, and E. coli were generated as maps to visualize the gathered data. The study aimed to evaluate the groundwater sources in the Municipality of Tantangan using water quality indices (WQI) which were calculated and were analyzed based on standards set by the Philippine National Standards for Drinking Water (PNSDW), World Health Organization (WHO), and Environmental Protection Agency (EPA). Results found out that in water hardness, three samples were classified as currently not potable and the rest were classified between potable to marginally potable, similar to the turbidity obtained. Most of the points in electrical conductivity lie between marginally to moderately potable as well as in results obtained in TDS. However, in terms of TSS and nitrate, and E. coli, seven or 100% of samples were classified as highly potable, while six samples for mercury and phosphate. In general, for the WQI calculation including mercury, 85.71% of the samples were rated as excellent and the rest as unfit for drinking. On the other hand, the WQI calculation without including mercury, 100% or equivalent to seven sample points, was rated as excellent for drinking purposes.