Effect of Monsoon Flood to Groundwater Quality in Kuala Krai, Kelantan, Malaysia

Abstract

Evaluation of water sources quality plays an important role during floods especially the groundwater. This study aimed to assess the effect of floods on the quality of groundwater in Kuala Krai. Six sampling stations were selected involving six main parameters, namely dissolved oxygen (DO), pH, biochemical oxygen demand (BOD), chemical oxygen demand (COD), total suspended solids (TSS) and ammonia nitrogen (NH3N). The assessment was conducted according to the Interim National Water Quality Standards Malaysia (INWQS) and the water quality index (WQI) classification, which has been established by the Department of Environment (DOE). The study found that flooding could affect groundwater quality, especially the DO, pH and BOD parameters. Based on WQI classification, most of well water stations are in Class III which is moderately polluted except the T6 station which is in Class II with clean status. This condition shows that the quality of groundwater in Kuala Krai is in the moderately polluted category and a full treatment is required for drinking water supply, especially during flooding events.