Author(s)

M. van Praagh & K. M. Persson

Abstract

Leachate constitutes the main potential long-term environmental risk of landfill emissions. The EU landfill directive 1999/31/EC requires minimum monitoring during the active landfill life and the after-care phase. Due to time and resource limitations, monitoring of leachate quality is a compromise between information density and applicability. Samples from passively collected leachate are suspect to mixing with groundwater and surface water. This is especially true for the widely used parameter conductivity. The objective of this work is to identify the extent of major external influences on conductivity monitoring data and its implications for future monitoring programs. A complete eight year conductivity monitoring data set from a municipal solid waste landfill in Southern Sweden is analysed with the help of multivariate data analysis. With the aid of a principle component analysis (PCA) the influences of surface water, groundwater and recycled leachate on the complete measurements’ variability is investigated. The impact of final capping on the variability is clearly reflected. A primary model is developed for the dependence of conductivity variability on water levels’ variability with the help of a canonical correlation analysis (CCA). On the one hand, the results allow identification of surplus sampling points. On the other hand, crucial sampling points are highlighted, which are intensively subject to processes other than mixing with surface water. Consequently, these results make way for tailor-made monitoring for comparable landfill situations. Keywords: landfill monitoring, leachate analysis, multivariate data analysis, electrical conductivity, final capping, leachate recirculation. 1 Introduction Landfilling of waste is the major waste management option in the EU. The main potential long-term environmental risk is posed by leachate emissions.

Keywords

landfill monitoring, leachate analysis, multivariate data analysis, electrical conductivity, final capping, leachate recirculation.