Impact Evaluation of a Decommissioned Landfill on Surrounding Groundwater Quality-a case study, Wang-Tien Landfill Site- southwest Taiwan

Department of Resource Engineering, National Cheng Kung University, No.1, University Road, Tainan City 701, Taiwan

Abstract

Landfill leachate composes the potential risk of terrible environmental contamination due to the release of diverse pollutants leaking from the containment system. Hence, a study of contaminant transport is of interest for its suitable management. The aim of this paper was to evaluate groundwater pollution risks from contaminants near the decommissioned Wang-Tien landfill site using a numerical approach. Stable concentrations of various physical-chemical parameters were determined in surface and groundwater samples collected from the study area. Principal component analysis was applied and identified chloride concentrations as the main indicators of groundwater contamination caused by landfill leachate. In this study, Groundwater Modelling System (GMS) was used to predict the subsurface migration of contamination within 1, and 10 years. The numerical results of chloride have shown that the concentration in the adjacent creek of landfill was 782 mg/l. However, the Monitoring Standard Value of Environmental Protection Administration (EPA, in Taiwan) for Taiwan defined the maximum value of chloride in groundwater for 625 mg/l. The result shows that chloride migrated widely to other places, such as the creek, and has had an adverse effect on the environment.