Waste separation at the UG is going well. Residual waste contains fewer organic waste and coffee cups. However, the contents of the orange bins for plastic and the grey bins for residual waste still end up in the same container.
The amount of separately collected organic waste and food residues has increased from just under 7,000 kilograms in 2015 to over 108,000 kilograms in 2022. A sample taken last year confirms the same trend. When examining 200 kilograms of residual waste, it was found that the percentage of organic waste had decreased from 35 percent in 2018 to about 15 percent in 2022. The number of coffee cups in that test had also decreased, from 9.4 to 5.6 percent.
Environmental scientist Sander Dijkstra with the Green Office considers this good news, although not all of the increase in organic waste can be attributed to employees’ efforts. The UG’s coffee bean machines also make a significant contribution. ‘And our waste statistics do not yet distinguish between coffee grounds and organic waste,’ he explains.
Covid years
However, the total amount of waste generated by the UG has also decreased. Between 2015 and 2019, it was around 500,000 kilograms per year. After a substantial decline during the coronavirus years, 2022 yielded approximately 320,000 kilograms. ‘But in the first months of 2022, we were still in lockdown,’ Dijkstra explains. So, the numbers are not entirely accurate yet.
Furthermore, people have been working from home much more since the pandemic. This is also evident in the UG’s overall waste streams. A total of 20 percent less was discarded: 800 tonnes in 2022, compared to 1,000 in the pre-Covid years.
The residual waste, which people throw into the grey bins, and plastic, in the orange bins, are still combined in a single container after collection, only to be separated again later.
Dijkstra acknowledges that this is ‘unfortunate.’ ‘When we started with this system, the idea was that we would be ready if we were to start delivering these streams separately. But now we know that we achieve quite good results with the post-separation process.’ Last year, this resulted in 28,000 kilograms of recyclable plastic.
Banana peels
An additional downside is that due to the merging of these two streams, some people mistakenly believe that at the ‘back end,’ all streams are combined again, which is explicitly not the case. Organic waste, paper, and coffee cups remain separated.
Moreover, additional organic material is extracted from the residual waste, which is then converted into green gas through fermentation. ‘We find a lot of banana peels in the residual waste,’ says Dijkstra. ‘And that’s strange. You can see that people make a great effort to separate properly, so why not throw that banana peel in the organic waste?’