HYDROGEOLOGY, QUALITY, AND GROUNDWATER VULNERABILITY ANALYSIS TO POLLUTION OF THE SOUTH AND SURROUNDING PANGALENGAN AREA, BANDUNG REGENCY, WEST JAVA

• Main Author: Nurrohman Susena, Fadli
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/69677
• Institution: Institut Teknologi Bandung

The background of this research is that the springs that used as drinking water by the community and many plantations that use chemical fertilizers suspected to be the cause of groundwater pollution. The purpose of this study is to determine the geological setting, hydrogeology, water quality, and susceptibility of the water to pollution in the research area. The methods used in this study include analysis of topographic maps and SRTM images; redesign of geological maps in the field; hydrogeological mapping; analysis of groundwater quality with parameters of physical temperature, pH, TDS, EC, ORP, and salinity; and groundwater analysis using the Susceptibility Index method (SI). The geomorphology of the research area is divide into seven units, which are the Windu Volcano Cone, the Pangalengan Intervolcanic Plain, Mount Wareng Pyroclastic Ridge, Mount Windu Pyroclastic Ridge, Mount Kancana Pyroclastic Ridge, Mount Ujungan Pyroclastic Ridge, and Mount Haruman Kidul Pyroclastic Ridge. The volcanostratigraphy of the research area consists of two khuluks, which are Khuluk Pangalengan and Khuluk Malabar. The gumuks in the study area consisted of five gumuks, which were Gumuk Ujungan, Gumuk Haruman Kidul, Gumuk Kancana, Gumuk Wareng, and Gumuk Windu. The volcanostratigraphic units of the study area consisted of twelve units consisting, which we Kancana Pyroclastic Flow Breccia (Kca), Wareng Andesite Lava (Wrl), Wareng Pyroclastic Flow Breccia (Wra), Ujungan Andesite Lava (Ul), Ujungan Pyroclastic Fall Lapillistone (Uj), Haruman Kidul Andesite Lava (Hl), Haruman Kidul Pyroclastic Flow Breccia (Ha), Pangalengan Pyroclastic Fall Tuff 1 (Pgj1), Pangalengan Pyroclastic Flow Breccia (Pga), Pangalengan Pyroclastic Fall Tuff 2 (Pgj2), Windu Andesite Lava (Wdl), and Windu Pyroclastic Flow Breccia (Wda). The geological structure of the research area is divided into two, the primary structure and the secondary structure. The primary structure consists of autobreccia, while the secondary structure consists of the Banjarsari Normal Fau lt, the Citawa Dextral Fault, and the Mount Windu Crater Structure. The research area's hydrogeological system is a volcanic deposit system with an unconfined aquifer. The aquifer units in the study area include the Haruman Kidul Breccia Aquifer, Kancana Breccia Aquifer, Pangalengan Tuff-Breccia Aquifer, Ujungan Andesite Fractured Aquifer, Wareng Andesite Fractured Aquifer, and Windu Andesite Fractured Aquifer. The results of groundwater quality analysis showed that there were twelve out of forty three springs that met the pH and TDS standards based on Minister of Health Regulation No. 492 of 2010. Based on the salinity value, the water in the study area is fresh water. Based on the results of the analysis of groundwater vulnerability to pollution, the research area can divide into 5 classes, which are very low vulnerability (44.8 – 48.93), low vulnerability (48.94 – 60.21), medium vulnerability (60.22 – 70 .53), high vulnerability (70.54 – 74.82), and very high vulnerability (74.83 – 85.3). The research area dominated by a high level of vulnerability, as indicated by the condition of springs that have pH and TDS values that do not reach drinking water quality standards.