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 CaHCO₃, and NaHCO₃. The CaCl facies, enrichment of Cl^- is caused by contamination of volcanic domain. The CaMgCl facies has enrichment of Mg²⁺ 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 NaHCO₃ facies is a wellbore in the intermediate groundwater flow and anthropogenic influences have occurred. The hydrochemical evolution that occurs is that Ca²⁺ becomes Mg²⁺ and then turns into Na⁺. The CaMgHCO₃ facies dominates the proximal to distal area. The presence of HCO₃ ^- 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 NaKHCO₃ 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.

The Cirasea River can provide water for both the Bandung basin and agricultural irrigation. Intensive agriculture, industry, and land use changes could have an impact on water quality. The purpose of this study is to look at the origins of heavy metals in riparian water resources. Heavy metal analysis was performed on 13 groundwater and river water samples. Heavy metals in water sources were compared with sediment and soil. The samples were analyzed for heavy metals using an AAS instrument. The research method employs statistical, geographical, and heavy metal pollution index (HPI). The HPI for river water was 131, whereas groundwater was 93. River water with an HPI value of more than 100 is highly polluted, indicating that it is unsafe for human consumption and has negative health consequences. Data verification with heavy metals in sediments reveals the presence of heavy metals coming from geogenic circumstances in various locations in the upstream area. Heavy metals in downstream areas result from geological factors and anthropogenic activities in the surrounding area. The long-term effects of heavy metal pollution along the riparian zone will become apparent. More research is needed on communities that depend on groundwater supplies along the Cirasea watershed.

The South Bandung basin has had significant population growth in the last ten years, particularly in the regions that border West Java. Consequently, there was an increase in the demand for groundwater, an essential resource for numerous uses. On the other hand, human activities have given impact significantly on the change of groundwater quality in the Bandung basin, the Malabar volcanic area. In the Bandung basin, the Malabar volcanic area has become an important location for urban water supply recharge. Within the current investigation 27 water samples were collected during the dry and wet seasons. The purpose of this study was to analyze the seasonal variability of parameters using different approaches. The comprehensive methods involving the application of multivariate statistics, geographical modelling, and the groundwater quality index. The spatiotemporal variability showed that the dilution effect of precipitation during the rainy season contributed to the significant seasonal variations. The hydrogeochemical facies was determined as Ca-Cl, CaMg-Cl, CaMg-HCO₃, and NaK-HCO₃. The Ground Water Quality Index (GWQI) analysis indicated that physicochemical factors influence water quality classifications from unsuitable to excellent. According to the conceptual model, the upstream area has excellent GWQI; however, the downstream area has decreased GWQI due to anthropogenic influence and the dissolution process. The results suggest that NH₄⁺-N, Fe²⁺, and Mn²⁺ have significant impact on GWQI. The novelties of this research include sensitivity analysis of each parameter to GWQI while conceptual model differentiates its findings from previous research. This conceptual model can be applied in various geographic environments to determine groundwater quality and its distribution regarding seasonal and land use changes.

The thermal springs in the Ciwidey region of Indonesia exhibit significant geological heritage and represent significant potential for natural therapeutic applications in medical geology. This study is for assessing hydrogeochemical characteristics of multiple thermal springs in the Ciwidey region and determine their appropriateness for natural therapeutic uses in medical geology. This research examines the hydrogeochemical characteristics of 13 thermal springs in Ciwidey using Atomic Absorption Spectrophotometry (AAS; AA-7000 SHIMADZU), classifying them into three distinct categories based on dominant chemical signatures: Sodium Chloride (Na-Cl), Calcium Sulphate (Ca-SO₄), and Sodium Bicarbonate (Na-HCO₃). Every hydrogeochemical type has unique therapeutic properties linked with their geochemical origin deep geothermal reservoirs, gypsum-rich lithology, or carbonate interactions. The analytical model established from this study identifies specific zones for potential therapeutic use: Na-Cl type waters (e.g. sites P2, P6, P10, P20) promote muscular relaxation and skin relief; Ca–SO₄ type springs (sites P3–P13) improve bone and joint health; and Na-HCO₃ type waters (P9, P14) aid in pH regulation and alleviate digestive and dermatological issues. The present research findings reveal essential insights into the therapeutic potential of Ciwidey’s springs and emphasize the significance of sitespecific assessments in medical geology.

The karst landscape of Trenggalek Regency, located in several sub-districts including Dongko, Kampak, and Watulimo, is shaped by the Wonosari Formation and is characterized by springs and underground rivers. Due to water scarcity in the region, local communities heavily depend on these natural water sources. This study assesses the groundwater quality of 16 springs and 20 underground rivers to evaluate their suitability for consumption and associated health risks. Using the groundwater quality index (GWQI), human health risk assessment (HHRA), and statistical methods, various physicochemical parameters were analyzed, including pH, total dissolved solids (TDS), electrical conductivity (EC), and concentrations of iron (Fe²⁺), manganese (Mn²⁺), calcium carbonate (CaCO₃), and sulfate (SO₄). Water generally meets the World Health Organization standards for safe drinking. However, correlation analysis reveals notable mineral dissolution and possible anthropogenic influence. TDS strongly correlates with EC (r = 0.97), while Fe²⁺ shows significant relationships with Mn and TDS. Conversely, CaCO₃ shows a negative correlation with EC and TDS, suggesting alternative sources beyond rock weathering. The HHRA indicates higher non-carcinogenic health risks from Fe²⁺ contamination in underground rivers compared to springs. The study’s novelty comes in its integrated assessment of groundwater quality and health hazards in Trenggalek’s karst region, which uses GWQI, HHRA, and statistical analysis to show geochemical interactions and highlight iron-related health issues in underground rivers.