ABSTRACT
Because of the heterogeneous nature of waste, some leachate will be generated almost immediately even for landfills designed with low infiltration covers. With low infiltration, it may take from decades to centuries before the field capacity of the waste is reached and full leachate generation occurs. This means that the full capacity of the leachate collection system may not be required for many decades after construction. However, during this period of time, degradation and biological clogging of the leachate collection system can be occurring unless the waste has been pre-treated to convert it to an essentially inert form. Furthermore, due to the variable nature of leachate generation, it may be difficult to assess whether there has been a failure of the leachate collection system by monitoring the volumes of leachate extracted.
