Evaluation of Groundwater Quality Status Around Gunung Tugel Landfill In Kedungrandu Village, Patikraja District, Banyumas Regency, Central Java, Indonesia.

Gunung Tugel Disposal Site (GTDS) is one of the final land disposal sites established in 1983 in the Banyumas Regency, and it operates with an open-dumping system. In this system, the base of the disposal site is neither coated with an impermeable layer nor equipped with leachate collection and drainage channels, for which leachate can percolate through the soil and pollute groundwater. In March 2016, GTDS was closed because its capacity had been exceeded. The closure of GTDS was not followed by appropriate waste and environmental management, prompting the formation of leachate that can contaminate the environment, particularly groundwater. This research set out to identify the leachate quality of GTDS, assess the groundwater quality, and determine the groundwater quality status around the disposal site. It employed a field survey and mapping to plot and display the groundwater well points in the study area, laboratory analysis to identify the groundwater quality, and pollution index calculation to determine the groundwater quality status. The groundwater samples were tested in the laboratory for their physical (turbidity and TDS), chemical (pH, COD, BOD, iron (Fe), cadmium (Cd)), and biological properties (total coliform). The results showed that the cadmium (Cd) levels in several groundwater well points had exceeded the quality standards. Based on the analysis and calculation results, the groundwater quality status in the study area is mildly contaminated, with the pollution index ranging between 2.571 and 4.099.