Hydrochemistry of groundwater at Sabahat region, Sabah

Abstract

The rolling land of the 8abahat region is currently developed by FELDA agency into one of the major palm oil estates in 8abah. The estimated total water demand for both domestic and palm oil industry is about 5.90 Mid. From hydrologic evaluation of surface and ground water, the latter appears to be the main water resource available in this region. Analyses of groundwater obtained from exploratory wells during pumping tests show that some of the groundwater, after proper treatment, are suitable for domestic and agricultural usage. Chemical analyses of groundwater samples show that there is a definite chemical contrast between groundwater from the northern and southern parts of the 8abahat region. The groundwater at the northern part of the region has proportionally higher concentrations of(Na + K) and (804 + Cl), with proportionally lower concentrations of (Ca + Mg) compared to the groundwater present in the south. The groundwater between these two localities has intermediate composition probably derived from mixing ofthe groundwater from the northern and southern parts of the region. The groundwater in the north is probably connate water of marine origin and not a result of sea water incursion, whilst groundwater in the south is probably influenced by the presence of gypsum present in the Ganduman Formation.