Diversion from landfill should be quantified objectively through a waste flow modelling exercise. If the Authority lacks the expertise in-house it will need to appoint specialist advisers to undertake this exercise.
In recent years, the LATS scheme has mirrored the EU Landfill Directive in targeting BMW with a view to reducing the level of methane emissions from landfill sites. This is a desirable policy objective as methane is a potent greenhouse gas. However, the effect of landfilling BMW and the impact of the resultant greenhouse gas emissions is captured elsewhere in the appraisal process (see Sections 4.4 and 4.7 below).
The reason for evaluating landfill diversion separately is to take account of the effects on resource use efficiency. This issue applies to any material that is landfilled not just biodegradable materials. Therefore landfill diversion should be included as an evaluation criterion but WIDP recommends this should be done by reference to the tonnage of MSW diverted not BMW.