RCHK’s Biodigester: how we need to help

By Cadence Elfassy & Ella Wong

In the Renaissance College cafeteria, at 1 PM every school day, students file through the white walls, push through lines of peers, and place their wallets in ready position to pay for what can only be described as a delicious treat. Servings of Siu Mai, yakitori, salads . . . Sodexo’s catering service provides it all, and this wealth of food is readily available for over 2000 Renaissance College students.

Yet, what happens when any individual takes too generous of a helping, or overestimates how much they can eat? It may seem like a simple solution — throwing the leftovers away, occasionally with the accidentally dropped fork. However, when accumulated, these scraps can drastically impact the state of food waste in our school.

“Don’t waste food” is a lesson relayed from parent to child across nations; but why? Food waste is a significant global issue that ties in with many others.

A third of all food produced worldwide is never eaten. This food trundles off to the landfill, where it not only occupies space and requires precious resources to transport, but breeds pathogens and releases methane as it rots. Methane is a greenhouse gas with 86 times the warming capacity of carbon dioxide, though it doesn’t last as long in the atmosphere as CO2. Food waste is a major factor in global warming, an issue that endangers everyone on the planet.

On top of that, the food that we eat every day takes an insane amount of resources, time, and environmental strain to create, especially at such a large volume. Take the beef balls in the noodles Sodexos occasionally sell; vast areas of land are cleared to raise the cows, felling natural habitats, freeing carbon dioxide absorbed by plants originally in the area, and disrupting local species; for instance, 5000 orangutans are estimated to die every year because their natural habitats are destroyed to make room for palm oil plantations. Then, cows have to be fed and watered before being slaughtered. Fossil fuels are burned to power vehicles with which to transport their meat, to power freezers where the meat is kept, and to power the stoves used when cooking the beef. When we throw something like a single beef ball away, the unimaginable immensity of resources it took to create that snack are lost forever. One kilogram of beef is estimated to have taken 50 thousand litres of water to produce; a typical beef ball weighs around 15 grams, meaning one discarded beef ball equates to pouring 750 litres of water right down the drain.

Food waste squanders and disrespects the effort and resources used to produce that food.

It’s a critical global issue, and one we all have a part in; one we all have a responsibility to mitigate through everyday actions. You could bring a container when eating out with a large group, to package any leftovers and take them home for later consumption. At a restaurant or in the school cafeteria, you could ask for less on your plate when you know you’re not hungry. But there’s no discount, you cry. Contrary to popular belief, asking for less doesn’t negatively impact your wallet, because you’re still paying for the same calibre of food; if you can’t finish the full portion, and leave the food uneaten, you’ll have wasted the same amount of money anyway. More importantly, it’s up to every individual to take responsibility for their own actions and make ethical choices regarding their consumption habits; including you.

There is also a systemic way to solve this problem at RCHK, without compromising on the large portions that our school offers, designed to meet students’ nutritional needs. The solution has been implemented by students, donors, faculty and staff, and focuses on recycling food waste using an anaerobic biodigester. It’s a machine that relies on microbes to anaerobically digest food waste and convert it into a liquid fertilizer.

We asked Vidya Madhavan, a Science teacher who helped spearhead the initiative, for more information:

“My Year 9 REAL students from the 2020/21 school year installed the first biodigester as part of a project-based learning initiative focused on food waste. Unfortunately, due to COVID-19 and school closures, we couldn't fully utilize the biodigester.

Now that the school is operating at full capacity, we recognized the need for a larger biodigester, which also aligns with our commitment to sustainability.

Some of my Year 9 REAL students, now in Year 12, took on the project of installing the new biodigester. After several rounds of tendering and negotiations, a generous parent donated the funds for the installation of the ORCA biodigester.

To ensure the biodigester operates at its full potential, we need to collect and feed all food waste from the school into it. As a first step, Sodexo, our school's catering service, has set up cardboard boxes for food waste collection. It's crucial that students only dispose of food waste in these boxes, avoiding the inclusion of utensils, fruit boxes, or plates, which have been a common issue.”

The designated collection bins set up by Sodexos in the school cafeteria and near the picnic tables—depicted here—are for food waste only. They feed into the biodigester. Tossing in other waste like plastic bags or utensils could jam and break the machine.

When reflecting on the powerful, positive impact the students, Science department and cafeteria staff have made on food waste within the RCHK community, one can’t help but be inspired to take individual action.

By asking for smaller portion sizes, throwing away only what can absolutely not be finished, and emptying only food waste into the specified bins for the biodigester, everyone can make a difference. Sometimes, the biggest problem can be solved by the smallest behaviour or habitual changes, and this is a brilliant example. Renaissance College needs everyone’s help to leverage the amazing benefits of the new biodigester. Simply reducing food waste and disposing of what is created appropriately makes a huge difference. We can all help build an environmentally sustainable world; therefore, using individual, collaborative will to improve a school and worldwide issue.

So, readers of The Truth, we challenge you to go forth today and make a difference in food waste, however you can.