Revealed: What the University of Cambridge throws away!

Out of sight, out of mind. That’s the mentality many of us have to waste. This may be even more the case at work, where unlike at home we don’t have the job of stamping down the bin bag in the kitchen dustbin, washing out the compost caddy, or lugging the heavy wheelie bin out to the curb each week. A study this month will most likely make for interesting reading for staff at the University of Cambridge. Thanks to a group of intrepid students, we’ve delved into the University’s bins to find out just what we dispose of!

The ‘bin busting’ study, as it has come to be known, was initiated by the University’s Living Laboratory for Sustainability, which aims to provide research to inform the University’s own sustainability performance. What better way for the University to understand the nature of its waste than to pull it apart bit-by-bit and record the contents! The University’s waste contractor, Mick George Ltd, helped source six randomly-chosen bins from around the University’s estate, and brought them to the Sidgwick Site. There, a group of a dozen intrepid students and staff occupied a car park for one afternoon, donning safety suits and masks and sorting through waste from each of the bins. A simple process of separating the waste into different types, and weighing the total amounts of each waste stream, helped determine the make-up of the contents. The study had been carried out on the ‘General Waste’ (previously known as landfill) bins last year, however this year the focus was on ‘Dry Mixed Recycling’ bins. In comparison to previous bin-busting studies it was a relatively clean and pleasant experience for the study’s participants! Fortunately there were no unpleasant surprises to be found – although some interesting book titles were found in a stack of journals disposed of in one department’s bin!

Once the study was complete, the Environment and Energy section crunched the numbers, and the findings have been turned into a handy ‘sankey diagram’, as shown above. This shows what proportion of each waste type by weight was found in the general waste and recycling bins, and whether it was recyclable or non-recyclable. What are the key findings, and what can we learn from it?

• Pulp fiction - Paper and cardboard were clearly the most commonly found type of waste in the mixed recycling bin. These materials are typically recyclable, which makes it a shame that a certain amount was found in the ‘general waste’ bin, which should only contain non-recyclables! Key learning point: Always put paper and cardboard items in the recycling bins! All offices should ensure that an easily accessible recycling bin is located in areas where lots of paper is disposed of, such as printer rooms and stationary or mailrooms.
• Plastic surgery - Plastics made up a surprisingly small amount of the weight of the recycling bins! This can only be good news for budding activists fresh from watching ‘Blue Planet II’, however it’s worth mentioning that plastic items can be very light compared to other waste types, so the use of weight as a measurement in this study could be misleading. We certainly spotted a lot of plastic cups and bottles – all the more reason to encourage a switch to reusable cups in your department, and to buy reusable, refillable drinks containers!
• Pen pals - Only a tiny amount of pens, e-waste and glass were found in the bins we audited. This is great news, as these items should be recycled through dedicated separate recycling routes for these items, including the pen recycling system set up by the Counselling Service’s green team. In future we hope that we will no longer find any of these wastes in either the recycling or general aste bins.
• Pipette hate - We produce a lot of non-hazardous lab wastes! The University is a research-intensive organisation, and much of the general waste was made up of non-hazardous items from laboratories, such as autoclaved petri dishes and pipettes, and plastic packaging and other items used for lab-based research. It’s clear that this is a tricky area to tackle, as safety and research concerns must take precedence, and reusable options are not always viable. However some departments have had success in reducing lab-related plastics.

Check out some photos from the audit on our Facebook page.

Take action on waste

Has this article given you inspiration for how you could reduce waste in your own department? Here's a few actions you could take today:

• Set up a Green Impact team in your department. Green Impact provides support to University Colleges and departments to help them improve their environmental performance, with awards at the end of the year. This includes a focus on waste & recycling. Visit our Green Impact pages for more information.
• Get in touch for statistics on your building's waste performance. We have over a year's data on waste collections from all University buildings served by the Mick George Ltd waste contract, which can help you monitor your progress.
• Read our 'waste & recycling guidance for University departments', which has plenty of ideas for tackling waste issues.
• Carry out a waste audit of your own department - we've got guidance on this here. This can help identify problem waste streams and areas for improvement.
• Identify areas of significant waste in your department. Could you replace plastic cups with washables ones? Encourage staff to use KeepCups? Get rid of lecture handouts? Go paperless for meetings? Consolidate stationary orders?
• Register for the WarpIt portal to find and distribute resources internally, for free.