Assessment of groundwater vulnerability towards contamination using SI (Susceptibility Index) in Demak Regency, Indonesia

Abstract Water is one of the sources of life for humans. In Indonesia, many people utilize groundwater as a water source. Groundwater management must be done properly so that its utilization is sustainable. The potential for groundwater pollution is getting bigger with land change. One form of mitigation of groundwater pollution is to assess the vulnerability of groundwater pollution to pollution. The research location is in Demak Regency, which is one of the regencies directly adjacent to the capital city of Central Java Province. This will have a direct impact on the development of the city. The most visible thing is the increasing population which will have an impact on groundwater utilization in Demak Regency. This research uses the Susceptibility Index (SI) method. The results of the analysis show that the research location is divided into 2 classifications, namely high vulnerability and moderate vulnerability. High susceptibility has an SI index value between 72-88 and moderate susceptibility has an SI index value between 55 - 71. The factors that have the most influence on the difference in groundwater susceptibility classification to pollution in the research location are the depth of the water table, slope and land use.