SPATIAL EVALUATION OF GROUNDWATER POTABILITY IN KORONADAL CITY, SOUTH COTABATO

The study aimed to assess the water quality of the groundwater sources of Koronadal City, South Cotabato. The water samples were taken from pitcher pumps, artesian wells, springs, and deep wells. Its main objective is to generate a potability map on the quality of water of the area under study using the QGIS 2.18.16 software. The data gathered in this study were the latitude, longitude, total dissolved solids, electrical conductivity, pH, hardness, phosphate, mercury, e.coli, turbidity, temperature in on-site gathering, while data on total suspended solids was gathered in a laboratory. The groundwater potability of the water sources was determined using a spatial analysis of each water quality parameters and water quality index. The results were compared to the standards set by the Philippine National Standards for Drinking Water (PNSDW) and World Health Organization (WHO). In general, using the Water Quality Index (WQI) without mercury majority of the sample under study passed with an “Excellent", only one sample rated as “Poor”, two samples fell under rating "Unfit for Drinking” and the rest is considered as “Good”. Therefore, this suggests that the majority of the groundwater is suitable for drinking. However if mercury is considered in WQI calculation, the result passed with 65.52% rated as “Excellent'' and 34.48% of the samples falls under rating “Unfit for Drinking”. The sample points that fall into excellent quality means the groundwater source is highly potable and applicable to be used in irrigation and industrial purposes.