Characterisation of treated wastes - headlines and more questions

Good quality waste characterisation data are fundamental to strategies to manage environmental challenges, yet the UK dataset for the new generation of treated wastes was poor. A three-year project funded by Defra, the UK Department for Environment, Food and Rural Affairs, aimed to fill some of the gaps in understanding the characteristics of residues from the treatment of municipal solid waste and industrial process wastes. The project has demonstrated the benefits of following a consistent sampling plan approach. It has generated a public domain characterisation database on composition, leaching behaviour and biodegradability for a diverse set of wastes, including kappa values (a way of defining the decreasing source term of a non-volatile contaminant) for a range of contaminants for landfill modelling. The project has also highlighted more questions that require further research e.g. in relation to the impact of application of partially stabilised wastes to land, leachability of organic materials and the longer-term monitoring of emissions and waste characteristics from organic waste treatment plant.