In selecting options the Authority will invariably have to make decisions on which technologies to exclude from the appraisal.
Typically the Authority will consider seven or eight options for treating residual waste. It is common practice to include a "business as usual" or "do minimum" option to act as a benchmark against which other options can be compared. By including this option it is usually possible to demonstrate that the project results in a significant reduction in carbon emissions relative to "do minimum". The "do minimum" option is also a useful reference point when considering the budgetary implications of the Reference Project.
For each option a waste flow schematic can be developed to illustrate the flow of waste from the point the waste arises through the treatment process to the end market or disposal point (see Appendix 1).