Modeling of Contaminant Transport and Groundwater Flow of Tamangapa Landfill in Makassar Indonesia

This paper aims to analyze the groundwater flow direction of Tamangapa landfill and to predict the contaminant in the groundwater over the period of 20 years, accounted for the year of 2000 until 2020. To understand the natural condition of the landfill, geological and hydrogeological survey were undertaken, consisting of geological survey, geomorphology and geo-resistivity surveys. Hydrogeological survey comprises groundwater level measurement, chemical analysis of leachate and groundwater samples which were later used as input data for numerical model. Based on the result of groundwater flow models, the direction of groundwater is found to be flowing from the north to the south. The minimum concentration for manganese (Mn) is 1.519 mg/l and 2.701 mg/l for iron (Fe). Over the period of 2020, Fe concentration increases significantly, reaching the level of 56.427 mg/l, Mn concentration for 299.5594 mg/l. It can be suggested that the groundwater quality of Tamangapa landfill has already exceeded the standard for water quality, leading to potential severe impact to local people around the landfill. Keywords: Landfill, modflow, groundwater, leachate, contaminant.