Analisis Persebaran Kontaminan Besi (Fe) dan Kromium Heksavalen (Cr6+) pada Air Tanah Dangkal Akibat Lindi di Sekitar Tempat Pemrosesan Akhir (TPA) Terjun, Kota Medan

Abstract

TPA Terjun is currently in a transition period from an open dumping system to a sanitary landfill. The leachate produced will not all go into the leachate pond, considering that currently the waste generation is high and not covered by land cover at the Terjun TPA. The resulting leachate can spread through infiltration into the soil and will follow groundwater flow. Leachate seepage into groundwater will affect groundwater quality. This research aims to analyze the distribution of iron (Fe) and hexavalent chromium (Cr6+) contaminants in shallow groundwater resulting from leachate around the TPA Terjun Medan City. Model simulations were carried out using the Domenico Robbins (1990) model using the MathLab application. The measurement results show that the metal pollutants Fe and Cr6+ in residents' wells have exceeded the quality standards in Minister of Health Regulation Number 2 of 2023. The results of the model simulation show that the heavy metal pollutants Fe and Cr6+ have spread up to > 700 m from the landfill. . Then predictions are made regarding the distribution of pollutants when the landfill is 40 years old and 50 years into the future. Fe contamination in the estimated 40 years since the landfill operated was spread over a distance of 750 meters with a pollutant concentration of 0.066 mg/L, and in 50 years it increased to 0.092 mg/L. Meanwhile, Cr6+ contamination over a period of 40 years at a distance of 750 meters spread with a concentration of 0.426 mg/L and increased in the 50th year by 0.600 mg/L.