GROUNDWATER VULNERABLITY TO POLLUTION AND QUALITY ANALYSIS IN NORTHEAST SIDE OF MOUNT MALABAR SLOPE, JAWA BARAT

• Main Author: Rifky Rizqullah, Mochammad
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/66969
• Institution: Institut Teknologi Bandung

Research area is located at the northeast side of Mount Malabar, specificaly in Bandung Regency with an area of research about 72 km2. Majority of people in the research area are using spring sourced groundwater to fulfill their daily needs. In some locations near the spring, is often found domestic waste and indication of iron oxide that could be a potential pollutant. Because of that, research about geological, geomorphological, and hydrogeological condition, groundwater quality, and vulnerability to pollution are needed. The methods that are used in this research are ground checking of geological map, hydrogeological mapping, groundwater quality analysis based on total dissolved solids (TDS) and potential Hydrogen (pH), and vulnerability analysis using susceptibility index (SI) method. Geomorphology of research area are consists of Malabar Caldera, Malabar Lava and Pyroclastic Flow Ridge, Malabar Lava and Pyroclastic Flow Fan, Malabar Lahar Flow Ridge, Mekarjaya Lava Dome, Malabar Foothills Plain, Citiis Valley, and Baleendah Volcanic Skeleton. The Volcanostratigraphy of research area are divided into 18 units based on 2 khuluks and 7 gumuks. Geological structures that are found in the research area are sheeting joint, Pangauban Normal Left Fault, Citiis Left Fault, Artapela Normal Left Fault, and Malabar Caldera Sector Collapse. Hydrogeology of research area are divided into 4 units of unconfined aquifer, the followings are Pyroclastic Breccia Aquifer, Laharic Breccia Aquifer, Sheared Andesite Aquifer, Tuff-Lapilli Aquifer, and Aquiclud. The results of groundwater quality analysis shows that all of the springs and wells surpassed the drinking standard based on TDS and 12 springs surpassed the drinking standard based on pH. Results of susceptibility index shows that the research area are divided into 5 classes of vulnerability (Very High, High, Moderate, Low, Very Low). “Very low” class covers 17 km2 area; “Low” class covers 10 km2 area; “Moderate” class covers 26 km2 area; “High” class covers 16 km2 area; “Very High” class covers 4 km2 area. Dominant factor that controls the vulnerability in research area are slope and recharge according to map removal analysis. Validation using coefficient correlation between SI with TDS shows low result (0,407), while SI with pH shows very low result (0,121). Low validation result can be caused by too much factor that controls TDS and pH, so further validation using nitrate value is needed.