HYDROGEOLOGICAL AND HYDROCHEMICAL STUDIES OF AQUIFERS SYSTEM FOR THE BENEFIT OF SUSTAINABILITY IN THE WALINI URBAN AREA, WEST JAVA, INDONESIA

A combined iso-potentiometric mapping and hydrochemistry study was conducted in the Walini urban area to assess the quality and suitability of groundwater for domestic and other purposes regarding Walini’s urban development. The direction of groundwater flow is northeast-southwest, based on observations from 22 water tables between 2022 and 2023. Groundwater samples obtained from dug wells, bore wells, and springs were analysed to determine physicochemical parameters (EC and pH) and concentrations of major ions. The result indicates that the groundwater is freshwater. It contains calcium (Ca2+), magnesium (Mg2+), sodium (Na+ ), potassium (K+ ), bicarbonate (HCO3-), and chloride (Cl-) in balancing levels. Piper diagram shows the groundwater was classified into calcium-magnesium-bicarbonate-chloride as dominant water facies. Gibbs diagrams reflect that the groundwater is hydrochemically controlled by lithology. Compared to the World Health Organisation’s (WHO) water quality standards, the water is appropriate for drinking and other domestic uses supporting urban development. However, compared to the shallow (4-20 m), the water quality of the deep (beyond 104 m) and middle unconfined aquifers (between 35 m and 73 m) is higher. This is because shallow aquifers are vulnerable to urbanisation. If current trends continue, appropriate management strategies for groundwater protection in the Walini would be critical for sustainability.