Determination of Water Quality Index (WQI) of Lanas River, Kelantan, Malaysia

In consequences of the pollution water, the ecosystems are affected due to water pollution because of human activities like dumping of garbage or sewage directly into the water bodies or use of chemical fertilizers from agricultural activities. Thus, the health of the water sources such as rivers or coastal waters can be determined by using Water Quality Index or WQI and National Water Quality Standard (NWQS) for Malaysia River. In this study, 19 parameters are conducted to determine the water quality and the factors that affecting the Lanas River, Ayer Lanas, Kelantan based on WQI calculation method which are ammoniacal nitrogen (NH3-N), biochemical oxygen demand (B0D), chemical oxygen demand (COD), pH, conductivity, salinity, total suspended solid (TSS), temperature, turbidity, fecal coliform counts, total coliform counts, zinc, cadmium, lead, copper, nitrite, nitrate and phosphorus. Three stations were marked as Point 1, Point 2 and Point 3 along the Lanas River, Ayer Lanas, Kelantan. The samples were taken from August until November. The overall WQI in August were calculated as 23.64 for point 1, 23.35 for point 2 and 25.03 for point 3 and was under class V due to heavy rainfall while in September, the level of WQI was under class IV for point 1 and point 2 except for point 3 was under class V. In October, the overall WQI were 34.13, 41.18 and 41.53 tinder class IV. As for November, all points were classified as class IV in WQI. 51.71 was the WQI for point 1, 38.98 for point 2 while 43.73 for point 3. Lanas River was supposed to be under class IIB which is suitable for recreational uses with body contact but the river was classified under class IV due to the pollution caused by the human activities done nearby.