With all the changes of Simpler Recycling and the Deposit Return Scheme (DRS) forthcoming, what will this mean for the amount and character of residual municipal waste? We are working with Integrated Skills on waste composition analysis, and one of the great things their composition analysis team does is to closely define sub-categories of waste to enable the effects of policy changes to be modelled.

Shown below is a worked example using real data from a rural authority with no food waste collection, analysing the impact of 4 alternative collection scenarios on residual waste tonnage and calorific value. This provides a good idea of the implications for energy from waste processes, in terms of the thermal input to the plant and (if applicable) Guaranteed Minimum Tonnage thresholds.

• Scenario 1 = Medium levels of Simpler Recycling (SR) – introduce collections of: food waste, plastic film, cartons, PTT - all with medium yield (no DRS)
• Scenario 2 = High levels of SR – introduce collections of: food waste, plastic film, cartons, PTT, textiles & WEEE – high yield, plus an increase in yield of other dry recyclables (no DRS) – e.g. like the impact of ‘3 weekly residual’ collections
• Scenario 3 = Medium levels of SR + DRS - As Scenario 1, but with DRS implemented (90% capture of PET drinks bottles and Al cans)
• Scenario 4 = High levels of SR + DRS - As Scenario 2, but with DRS implemented (90% capture of PET drinks bottles and Al cans)*

What can be seen in the orange bars, in all alternative scenarios, is a significant reduction in tonnage (c.17% - 26%) and a notable (c.3- 5%) rise in net calorific value from c.8.1MJ/kg (baseline) to between 8.3 and 8.5MJ/kg. The Deposit Return Scheme has very little impact on either the tonnage or the calorific value (i.e. comparing Scenarios 1 and 3, 2 and 4), as most of these materials are already out of the residual waste in this case (and aluminium has an effective zero CV whilst plastic a very high CV, but there are not that many bottles relative to the rest of the waste). A key factor in respect of both tonnage and CV for residual waste is the removal of a significant proportion of food waste. Whilst plastic film has a high CV it is a relatively small element of residual waste, so its separation is not sufficient to drive CV down, in net terms, under this Council example.

This is an example from one context, there would be very different implications for Councils that already collect food waste, or from some urban authorities.

Another key aspect of these changing residual waste scenarios would be the impact of these changes on ETS liability, and also what might changing behaviours from packaging producers under pEPR do for residual waste composition and CV? These will be the subject of another blog for another day!

Frith Resource Management undertake strategy modelling, collections modelling, waste composition analysis and have worked with >135 Councils on waste projects in the UK. For details see www.frithrm.com tel. 01746 552423 or email paul@frithrm.com