Developing Strategy for Establishing Landfill Gas as Cause of Ground-Water Contamination

Abstract

The purpose of this paper is to describe some of the tell-tale characteristics of contaminant transport to ground water via gas migration from municipal solid waste landfills, and corresponding investigative techniques that can be used to identify when this is occurring. Some fundamental principles are presented that can be used to distinguish between ground-water contamination through gas phase (landfill gas) versus liquid phase (leachate) migration. Then, specific techniques are presented, based on these principles, that have been used in field investigations to determine whether gas phase or liquid phase contaminant pathways predominate. These are combined into an overall strategy that can be used to evaluate and identify the extent and direction of a gas-phase vadose zone contaminant pathway. Finally, a case study is presented that illustrates some of the principles and techniques cited.