Cipayung Landfill is the last disposal location of waste processing in Depok City, West Java. In a day, approximately 800 tons of garbage is dumped, which is then processed by being burned and left to decompose for inorganic and organic waste, respectively. However, poor waste management has resulted in an accumulation that continues to this day. This creates a variety of problems, especially leachate contamination that infiltrates to the groundwater, flows along and threaten the health of residents who live in the vicinity. This liquid contains toxins and hazardous materials. Therefore, it is essential for residents to know the level of contamination occurred and its dispersion, along with actions that must be taken to reduce the impact of pollution. In this study, we map the distribution of contaminated groundwater using the geophysical ground penetrating radar method, together with the chemical analysis of water samples. Ground penetrating radar has been useful to detect the change of permittivity and conductivity of layers below the surface. It is possible to mark off the contaminated groundwater to the fresh one indicated from an extensive amount of electromagnetic signal attenuation. This study suggests that there is contamination occurred in radius up to hundreds of meters from the landfill site. The result of this community-based research gives an advisable policy regarding waste management and groundwater usage in this area.

The detailed mechanisms of volcanic eruptions happened around Rawa Dano, Banten, Indonesia, remain undiscovered. One of the key features to this geological event is the presence of a 13.7 km × 6.5 km caldera-like morphology in the middle of Banten tuff deposits. Surface geological investigation in the area indicates that the eruptions are massive and occurred in several periods. Low-frequency ground-penetrating radar (GPR) signals are used as an aid to identify the unexposed part of the deposits in this volcanological study. Common-offset GPR surveys were carried out along three measurement lines traversing over the deposit outcrops. An outcrop which is exposed after sand mining activities at one of the survey locations shows dipping interfaces between the upper pyroclastic flow deposits, pumice-rich deposits, paleosol, and the lower pyroclastic fall deposits. These stratigraphic contacts are detected as well under the surface which are clearly recognizable in radar images. The GPR cross-section also shows some other reflections due to different deposit types. The overall results of the GPR profiles give the idea about the thickness of each type of volcanic deposits and the paleotopography in the surrounding area.