Impact of natural conditions and anthropogenic activities on groundwater quality in Puntang volcanic area, West Java, Indonesia.

Abstract The Puntang area in the southern mountains of West Java has potential water resources that are used to fulfill the community's raw water. The rapid development of the region and tourism will affect the quality of groundwater. This research was conducted on the slopes of Mount Puntang with the aim of analyzing natural and anthropogenic conditions on groundwater quality. Measurements and groundwater samples are taken from 5 springs, 10 dug wells and 8 drilling wells. The research method begins with a literature study followed by data collection in the field and laboratory analysis. Data analysis used statistical analysis and hydrogeochemical spatial analysis. Hydrogeochemical analysis using Piper diagrams. Based on the analysis results, it is known that the groundwater facies are CaCl, CaMgCl CaHCO 3 , and NaHCO 3 . The CaCl facies, enrichment of Cl - is caused by contamination of volcanic domain. The CaMgCl facies has enrichment of Mg 2+ cations in the process of groundwater and rock water interactions. The high Cl - value in the proximal area is influenced by volcanic domain, while the Cl - value in the medial and distal areas may be influenced by anthropogenic. The CaHCO3 facies is influenced by local meteoric water, with a high structural control that shows water flowing through the fracture. The NaHCO 3 facies is a wellbore in the intermediate groundwater flow and anthropogenic influences have occurred. The hydrochemical evolution that occurs is that Ca 2+ becomes Mg 2+ and then turns into Na + . The CaMgHCO 3 facies dominates the proximal to distal area. The presence of HCO 3 - indicates that groundwater mixing has occurred and is influenced by the decomposition of organic matter. Indications of groundwater mixing can be seen in groundwater with NaKHCO 3 facies in the distal area. The medial and distal areas are densely populated areas which also affect groundwater. Geological and environmental conditions around the water resources are one of the supporting data to determine polluting sources.