Track: Undergraduate Student Paper Competition

Abstract

The Special Capital Region of Jakarta is covered in densely growing infrastructure. However, little attention is paid towards its environmental conditions. This leads to social problems such the absence of a clean water supply. The conditions of contaminated shallow groundwater and river water makes layer analysis of deep groundwater carriers (aquifers) necessary. This research aims to provide insight about deep groundwater potential, and determine the depths and locations of aquifers in the Jakarta area, particularly for the benefit of the Kapuk-Cengkareng people. This research was conducted via well logging analysis. Well logging is a geophysical method designed to find out the subsurface lithology of an area using its physical characteristics. The result from this research can be used to interpret that there are four deep groundwater layer zones with different qualities. Good groundwater layers can be found in layers with good porosity and permeability. By analyzing the curves obtained using the well logging method, it can be known that most of the layers found in the wellbore are claystone with low resistivity and high gamma radiation. The resistivity value of the claystone layers is about 2-5 Ω•m with 65-80 cps. There are several layers with high resistivity and low gamma radiation (sandstone) that has the potential to be an aquifer. This is reinforced by the sand layer with a right-leaning SP log curve proving that this layer is permeable. These layers have a 4-9 Ω•m with 40-65 cps. These are mostly found as freshwater aquifers with (83-279) µ•S/cm EC, (7.61- 8.17) ph, and (56-188) mg/L TDS.