Evaluation of the potential contamination risk to groundwater posed by municipal landfill leachate.

摘要

This study was undertaken to provide a better understanding of the phenomena that influence landfill leachate generation and migration to groundwater. A number of methods were evaluated and proposed to investigate the issue of groundwater contamination by municipal landfills. The tools discussed and applied to assess the City of Regina landfill leachate generation potential include siting and classification tools, water balance modeling, interpretation of landfill, groundwater and leachate data, waste contaminant sampling, and final cover design. In addition, the hypothetical human health risks from drinking groundwater in the vicinity of the landfill were estimated.; The study showed that siting and classification tools are useful in the planning and design stages but can also be applied to evaluate risk at an existing landfill. Water balance methods and the HELP model can be used to estimate leachate production with a minimum margin of error if key site-specific parameters are known. The model's simulated results showed that the leachate generation potential is low at the Regina landfill, and follows the precipitation pattern. The groundwater, waste and leach samples suggest a weak strength leachate. Waste contaminant analysis indicated the landfill is in a mature methanogenic stabilization phase, which is in agreement with the age of the landfill. The health risk estimation revealed that the risks from drinking the affected groundwater are within acceptable ranges. Finally, the results obtained from modeling, risk estimation and analyses of the data at the Regina landfill are discussed, and future lines of research are proposed.