Groundwater geochemistry and hydrogeochemical processes assessment in Bantul, Yogyakarta, Indonesia

Abstract In Bantul, Southern Yogyakarta, groundwater is the main source of domestic water needs. Therefore, knowing hydrogeochemistry crucial in order to manage a sustainable resource. To characterize compelling geochemical processes that control chemistry, further hydrogeochemical examinations were directed area. Thirty samples collected from shallow dug wells during early dry season (April 2021). Sampling procedures and chemical analysis carried out as per standard methods with secondary data obtained 2006. The evaluations depicted using several graphical plots dependent on ionic constituents, hydrochemical facies, controlling factors quality. Two major facies identified: alkaline-earth higher alkali; bicarbonate predominated (62%) water; (32%). Weathering silicate minerals occurs 70% recent predominantly regulates ion chemistry such calcium, magnesium, sodium, potassium. Chloro-alkaline indices 1,2 values signify there are two potential rock-water interaction study region, namely exchange reverse exchange. Concentrations nitrate, sulfate, chloride indicate has not been heavily contaminated by land use area still mainly controlled geogenic rather than anthropogenic activities.