3.1 Introduction

A proposed generic BPEO was arrived at after detailed appraisal of a number of options and further amended after public consultation. Options were assessed against 14 nationally agreed social-economic and environmental decision criteria to assess the best performing option. These options were also subjected to life-cycle assessment by use of WISARD software. WISARD examined each option's use of finite and renewable resources and emissions to the environment through the entire operation of the waste-management system³. The generic approach of the adopted BPEO for the Waste Strategy Area is set out in Figure 3.1 below.

The model places an emphasis on the minimisation of waste at source and thereafter seeks to limit or minimise the amounts of materials falling to lower order of the hierarchy. The key values being expressed in this model are: commitment to reducing waste at source, a commitment to increasing the reuse, recycling and/or composting of materials through the use of source separated collection systems, a commitment to ensuring that the remaining waste, i.e. the mixed waste, does not go direct to end point disposal. In keeping with the aims of the hierarchy, mixed waste should be treated so as to further recover materials for recycling and/or composting, etc., thereafter consideration should be given to the further recovery of value from the waste. It is envisaged that the reliance on landfill be minimised, but no material will go directly to landfill and that only the residuals and unsuitable elements that fall out of the processes would end up being landfilled.

The detailed assumptions that went into the development of the BPEO along with the appraisal outputs are set out within the 'WISARD Modelling Assumptions' documents and is sourced within Annex 4 Associated Documents (Modelling Data).

Figure 3.1 - Generic Model (Repeated)

³BPEO Decision Making Guidance.