Case Studies

Kerbside Best Practice

Since 2007, CEC has undertaken an annual survey with Scottish Local Authorities to examine the performance of kerbside recycling schemes. Local Authorities have been using the results of the analysis in order to better understand the impact of policies and how they can improve service performance. Multi-criteria regression models were built to identify the most influential factors on recycling rates.  The results presented within the report help Local Authorities understand the relative performance of their services and the potential factors underlying the variations across all Scottish Councils, informing policy makers with real primary datasets.
 
An online benchmarking tool was also developed to allow Scottish Local Authorities to assess their performance and yields against various factors including, best in class, similar family types (i.e Urban, Rural or Mixed), frequency of residual and recyclate collection and by material.

Client: The Scottish Government, Zero Waste Scotland
 

Participation Monitoring & Service Improvement Option Assessments

CEC assisted Glasgow City and Renfrewshire Councils in improving service quality by providing a better understanding of route performance, identifying potential operational modifications and target areas for public engagement. The findings from these projects helped Councils identify areas and routes where additional public engagement campaigns were likely to have the greatest impact: CEC coupled route data (e.g. number of households, route yield, deprivation indices and council tax data) with primary data (e.g. set-out rates), to produce daily performance indicators for each collection route.

Using a methodology corresponding to (but pre-dating) WRAP’s sample size guidelines, set out rates were determined for high and low performing routes. In addition, 10% of presented containers were surveyed to determine range and quality of recyclates presented. To provide a comprehensive understanding of route performance, CEC also recorded information about: number and range of containers, average yield by volume, contamination levels and rejection rates.

Clients: Renfrewshire Council, Glasgow City Council

Assessment of Kerbside Recycling

CEC was commissioned to investigate the impact that different yields might have on service operational requirements.  Using statistical analysis, CEC evaluated the impact that the following parameters had on route performance: route characteristics (e.g. number and type of household); predominant socio-economic characteristics (e.g. Scottish Index of Multiple Deprivation in the Scottish Neighbourhood Statistics data zone serviced by the route); and participation rates (calculated using two consecutive set-out surveys, rather than the standard three due to resource limitations). This analysis revealed that route yield was influenced by the proportion of flatted properties, participation rate and yield per participating property.
 
CEC used this data to model how improving route yield would impact on the Council’s recycling performance.  The results were used by the Council to plan public engagement campaigns in areas where they were likely to increase set-out weights and participation rate.

Client: East Renfrewshire Council / Zero Waste Scotland.

Modelling Capacity and Costs for Materials Recycling Facility

CEC has developed an integrated financial and recycling performance modelling tool that accurately evaluates the fixed capital costs and ongoing gross and net operational costs for material recovery facilities (MRF).   The model assesses the contribution from either detailed or high-level MRF configurations on overall recycling performance or landfill diversion rates. Adopting a material flow approach, the impact that different processes/technologies have on the initial waste composition can be considered. CEC has brought together expertise around collection systems, MRF plant design and performance, recyclates quality and market value and a wide range of other parameters that affect the financial and environmental performance of this type of facilities.

The MRF tool was used, on behalf of the Scottish Government, to model the additional capacity required, and associated costs, to provide the necessary infrastructure to process the additional comingled dry recyclate collected through the planned expansion of ‘blue bin’ schemes in Scotland. 

The tool has most recently been used to conduct a review of the potential for a MRF to be owned and operated by Highland Council.  The project modelled the impact of a new integrated comingled scheme and assessed the potential yield.

Client: The Scottish Government, Highland Council.