Geology and evaluation sea water intrusion in shallow aquifers using hydrochemistry in Tumpat, Kelantan

The study is about geology and evaluation of seawater intrusion in shallow aquifers using hydrochemistry in Tumpat, Kelantan. Intrusion of seawater in shallow aquifers is very serious issue as it can be one of the source of groundwater contamination. Water samples which 14 groundwater samples from different wells and 1 river water sample were collected and analysed for pH, temperature, total dissolved solids (TDS), electrical conductivity (EC), turbidity and salinity by using multiparameter and portable turbidity meter. Meanwhile calcium, sodium, magnesium, iron, potassium, chloride, bicarbonate and sulphate were analyzed through atomic absorption spectroscopy analysis, gravimetric analysis and titration analysis. Sea water intrusion evaluated by using the result obtained from the analysis of water samples. The result showed 2 type facies of shallow aquifers which were sodium-bicarbonate and calcium-magnesium-bicarbonate which determined by Piper Trilinear diagram. Meanwhile, all groundwater samples lied within normal groundwater zone based on a graph of chloride against electrical conductivity. The data for geology of Tumpat, Kelantan obtained from alluvium mapping, geomorphological mapping and investigation of soil. New geological map produced by ArcGIS software based on the geological data.