Geology and groundwater quality assessment in Kampung Ayer Asahan Hulu, Tanah Merah, Kelantan

The main purpose of the study is to update geological map of study area on the scale of 1:25,000 and to assess the groundwater quality in domestic wells in study area. The study area covers around 25.5 km2 of the area and lies between latitude from 5o 46’34.58” N to 5o 49’20.56” N and longitude from 102 02’16.57” E to 102o 05’00.06” E. Study area includes some villages and a highway known as Timur-Barat Highway. Some methods were being used in the study such as preliminary study, geological mapping, traversing, field observation, fresh outcrop sample collection, petrographic study and GIS analysis. For groundwater quality assessment, water sample were taken to laboratory for analysis by Atomic Absorption Spectrophotometer (AAS), UV-VIS Spectrometer and by titration method. In-situ parameters such as Total Dissolved Solids (TDS), pH and temperature of the groundwater were taken. Based on the study, the north part of the study area are mostly covered with metamorphic and metasedimentary rocks such as schist, quartzite and meta-mudrock. These rocks can be found in the same area and the schist were composed of mostly quartz minerals. In some areas in the south part of the study area, igneous rocks such as coarse-grained porphyritic granodiorite were found. Granodiorite was mostly composed of quartz mineral along with plagioclase, biotite and microcline minerals. In terms of geomorphology, the study area comprises mostly low hills with elevations ranging from 40m to 160m. Mostly the locations where outcrops are most likely be found were weathered and many places were being developed and currently became cutting areas. Therefore, fresh outcrop were hardly found. Some joints and fault structures were discovered such as reverse fault on a weathered outcrop. Updated geological map can be used by many other beneficiaries for many uses related to development of the area. Based on the result for groundwater quality assessment in study area, most of the groundwater sample consist of major cations and anions within permissible limit under guidance of W.H.O. and Malaysia M.O.H. except for one well labelled as U10 consisting a higher concentration of Ferum ion which is 2.392 mg/l over permissible value of 0.3 mg/l. Although ferum ion does not usually present in health risk, a high concentration of the particular ion should be paid attention to