During August and September 2015 participation monitoring was carried out. The purpose was to understand the level of households using the dry recycling and food recycling service across the area.
It is not possible to monitor all households so a representative sample was selected using social demographic profiling. The method used followed guidance from ‘WRAP (2010) Improving the performance of waste diversion schemes: A guide to monitoring and evaluation’. This states that a participating household is one that sets out its recycling at least once in three consecutive collection opportunities. ‘Set out’ refers to the percentage of households that put their recycling out for collection on a given week.
Four dry recycling rounds and four food rounds were selected for monitoring. The sample size covered 3,000 properties and monitoring took place over six weeks. These rounds were selected as they demographically matched the authority as a whole. Householders were not aware that waste was being monitored.
Data over the six weeks showed that 89.5 percent used the food recycling service at least once, which appears very high but in reality the participation is much lower as this data gave households six opportunities to use the service and only used it once. To be consistent with WRAP guidance of collecting data over three opportunities, the data is halved, so actual participation is nearer 45 percent.
The data from each week by round highlights the lower level of set out. The average over the period was 43.1 percent, with the lowest level 28.5 percent and the highest 53.6 percent.
Figure 8: Table – Food waste participation by round
|Round||Sample size||Week 1||Week 2||Week 3||Week 4||Week 5||Week 6||Average|
Weeks 1, 3 and 5 are residual waste weeks.
The results showed there were also a substantial number of households that only use the food recycling service from time to time. 20.6 percent used it once in six week period and 20.9 percent used it twice over the six week period. Only 16 percent of households put out the food recycling bin every week.
The data also highlights a pattern of higher participation of food recycling on weeks where the black bin is not due to be emptied. For the 3,049 households, those presenting food recycling on black bin collection days was 35.7 – 38.5 percent compared to 46.1 – 51.6 percent on recycling only weeks.
Plastic is collected fortnightly, so there were three opportunities to present it during the six week monitoring period weeks 1, 3 and 5. It was encouraging to see high levels of participation, the average participation was 88.3 percent. This means that on average 88.3 percent use the plastic recycling service at least once in every three opportunities.
The set out rate, the number of households using the service on a given week was lower but still highlighted good engagement in plastic recycling. With the average set out of 65.9 percent means that almost 66 percent of people use the plastic service every time a collection is offered.
Figure 9: Table – Plastic set out rate by round and week
|Round||Sample size||Week 1||Week 3||Week 5||Average|
Cardboard is also collected fortnightly on the alternative week to plastic. There were three opportunities to present cardboard during the six week monitoring period weeks 2, 4 and 6. The average participation was higher than plastic at 92.7 percent this means on average 92.7 percent of households use the cardboard recycling service at least once in every three opportunities.
The set out rate was lower than plastics at just over 60 percent.
Figure 10: Table – Cardboard set out rate by round and week
|Round||Sample size||Week 2||Week 4||Week 6||Average|
Dry recycling – paper
Dry recycling is collected fortnightly and was collected on weeks 2, 4 and 6 of the monitoring. A green bag is used to collect paper. The average participation for paper was lower than both plastic and cardboard at 68.6 percent. This means on average 68.6 percent of households use the paper recycling service once in the three opportunities during the monitoring period. Paper is a waste stream on the decline with the advance of digital technology.
The set out rate was less than half at 42.2 percent.
Figure 11: Table – Paper set out rate by round and week
|Round||Sample size||Week 2||Week 4||Week 6||Average|
Dry recycling – green box
Dry recycling is collected fortnightly and was collected on weeks 2, 4 and 6 of the monitoring. The residents use a green box to present glass, metal, cartons, textiles, small electrical items and foil. During the monitoring period 77.8 percent presented a green box. The average participation by stream presented in the green box was as follows:
Figure 12: Table – Green box participation by stream
|Cartons / Tetra||24.1%|
|Small electrical items||5.1%|
The set out by material mirrored the participation in terms of streams presented but the levels were lower. There was very little variation between the three collections of the set out rate.
Figure 13: Table – Green box set out rate by stream
|Stream||Week 2||Week 4||Week 6||Average|
Residual black bin waste
Residual waste is collected fortnightly from the black bin and so there were three opportunities to present the black bin during the six week monitoring period. There is a risk with data for residual waste where empty bins may have been taken back in by residents before the monitors reached the property. However the results do give an indication of usage.
The results show high participation with over 90 percent presenting their residual black bin at least once. The residual waste collection also had the highest set out rate with an average of 66.1 percent of households using the service at every collection opportunity. The data suggests that some residents do not need to set out the residual black bin at every collection opportunity and so therefore may have spare capacity in their bin. This result also correlates with the waste analysis which shows an average bin as 75 percent full.
In general the recycling services are well used. The dry recycling streams showed high participation especially for the bulkier items like cardboard, (92.7 percent) and plastic (88.3 percent). The level of recycling for paper is lower at 66.8 percent.
Participation in the dry recycling box was good at 77.8 percent and the box was predominantly used for glass and cans with around a quarter also using the box for cartons and aluminium foil. Use of the dry recycling box for small electrical and textiles was very low.
Food recycling participation was less than half at 45 percent and the set out analysis also suggests that households do not consistently use the service. This may suggest a lack of understanding or confidence in the service.
There is also some evidence that residents are more likely to put recycling out on recycling only weeks as participation is reduced on residual black bin collection weeks.
Relevance to the strategy
The participation monitoring highlights four main findings that have been incorporated into the strategy: