A Critical Evaluation of Factors Required to Terminate the Post-closure Monitoring Period at Solid Waste Landfills.

Abstract

The objective of this research is to identify and evaluate parameters that could be useful for defining the end of the post-closure monitoring period, or that time at which the landfill is stable with respect to environmental emissions. Parameters evaluated in the report include leachate composition, leachate production, and gas production. In addition, the evaluation of leachate composition and quantity is combined to evaluate surface water impacts associated with the release of leachate to surface water. To determine if a landfill has reached stability, the following data are needed: the concentrations of ammonia and BOD in the leachate, leachate production rates, and gas production rates. In order for the landfill to be declared stable, the leachate should not deplete oxygen resources, exert toxicity, or increase eutrophication if it is released to surface water. In addition, gas production rates should be low enough so that their emission does not represent a significant release of a greenhouse gas or cause an odor nuisance or explosion hazard. Ultimately, the technical criteria for landfill stability evaluated in this research should be applied to a full-scale landfill to test the usefulness of the proposed approach.