Geology and saline water intrusion studies in coastal aquifers of Pengkalan Kubor area, Kelantan

This study was undertaken to produce an alluvium map of the study area in Pengkalan Kubor, Kelantan and to evaluate saline water intrusion in the shallow aquifer of the study area. Saline water intrusion occurs when saline water intruded into aquifer and mixes with the freshwater. Since the study area is a part of coastal area, its shallow aquifer has the possibility of being contaminates by saline water intrusion. Field and laboratory analysis were conducted, where 14 groundwater samples from domestic wells were analyzed. In-situ parameters of the groundwater samples were measured using multiparameter, turbidity meter and TSS Portable Meter. Major anions (CI-, HNO3- and SO4) were analyzed by using titration method and gravimetric method respectively while all major cations (Na+, K+, Ca2+, Mg2+ and Fe) were analyzed by using Atomic Absorption Spectrophotometer (AAS) method. Based on the result, only groundwater sample 2 found to be contaminated by saline water intrusion meanwhile other 13 groundwater samples were not showing reflection of saline water intrusion. In Piper Trilinear Diagram plot, sample 2 and seawater sample lie on calcium magnesium bicarbonate type which proved seawater sample and sample 2 have similar origin. Graph of chloride (CI-) versus EC show that sample 2 lies in saline water intrusion zone.