Setting a challenge to landfill modellers

A modelling challenge made to international research groups with landfill modelling capabilities is described. The challenge invited participants to model and predict the performance of a well-constrained laboratory experiment on the settlement and biodegradation of municipal solid waste (MSW). Data on the set-up and operational procedures of two laboratory-scale waste reactors were provided, together with limited results on leachate chemistry in the first two months of a 2½-year experiment. Participants were then invited to submit their modelled predictions over time for any (or all) of: waste settlement; degradation and gas production; evolution of leachate chemistry. Results from the exercise were collated by an organising committee prior to presentation and discussion at HPM2, an international workshop on the hydrological, physical and mechanical behaviour of landfills.