ANALYSIS OF PUMPING TEST DATA AND GROUNDWATER QUALITY IN SOUTHERN JAKARTA

• Main Author: Patrick Hartono, Mikael
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/69704
• Institution: Institut Teknologi Bandung

Administratively, the research area is located in DKI Jakarta with an area of 187.96 km2. DKI Jakarta has a high population and industry, thus, the need for groundwater is also high. Currently, there are two main problems that need to be adressed in DKI Jakarta, namely land subsidence and groundwater contamination. Excessive groundwater extraction can cause land subsidence. Moreover, an increase in the amount of domestic waste is expected to be a source of the groundwater contamination. To analyze the magnitude of the subsidence, aquifer parameter values are needed. Furthermore, the groundwater quality needs to be analyzed to determine the potential for groundwater contamination. Therefore, this study was conducted to estimate the aquifer type and the value of aquifer parameters in the study area, as well as to evaluate groundwater quality based on physical and chemical parameters of groundwater. Based on the literature, the research area is divided into two geomorphological units, namely the Coastal Plain Unit and the Bogor Volcanic Fan Unit. Stratigraphically, there are two formations discussed in this study, namely Kaliwangu Formation with Pliocene age and Citalang Formation with Pleistocene age. Both of these formations are included in the Jakarta Groundwater Basin and act as aquifers in the study area with rock units in the form of alternating sandstone and claystone. Aquifer parameter values were analyzed using data from 11 wells, while groundwater quality analysis was carried out using data from 16 wells. All wells are estimated to penetrate Aquifer Zone 2 in the Kaliwangu Formation. From the analysis, there are two types of aquifers in the research area, namely confined and leaky aquifers. The results of the aquifer transmissivity estimation show a range of 1.28 ×10?5 to 2.79 ×10?3 m2/s. The TDS values in the study area ranged from 76 – 1,004 mg/L, lead levels 0 mg/L, copper levels 0 – 1 mg/L, zinc levels 0 – 3.33 mg/L, and pH values of 5.63 – 10.46. Some of the TDS and pH values in several wells did not meet the standard of Permenkes No. 32/2017, but the lead, copper, and zinc values in all analyzed wells met the Permenkes standard. In the study area, there are three groundwater facies with the type of NaHCO3, Ca(HCO3)2, and non-dominant.