A school's journey to sustainable self-sufficiency

Yarrells School set out on a path to sustainability by turning its food waste into compost for their gardening club, fruits and vegetables, as well as their forest school area. They also aimed to create organic fertiliser using vermiculture, a process of cultivating worms to decompose food wastes into compost.

Additionally, the school wanted to start collecting their own rainwater, which it can use when making fertiliser.

Harvest rainwater and create wormery to generate organic fertiliser

As part of its triple bottom line approach, SUEZ is always eager to support existing customers with sustainable solutions. After considering various options, both parties agreed to kick off the initiative by harvesting rainwater at the school. Ensuring that sustainability is at the heart of this project, SUEZ partnered with Olives Et Al, a company that has been seeking a disposal method for its large, barrel-like containers made from the more sustainable green plastic. These containers make fantastic water butts when reused. SUEZ successfully ensured that these containers found a new purpose at Yarrells School.

For composting, Yarrells’ groundskeeper created a dedicated area within the school grounds with specific bays for each stage of development. This segregation prevents cross-contamination and allows for better monitoring of the composting materials.

The first bay is for collected leaves, grass cuttings, and vegetable peelings. The bay undergoes periodic turning to start the anaerobic process. When the composting materials have significantly broken down, these partially composted material are transferred to the second bay. After a few weeks, the compost will have matured leading to the final process of having a fully broken-down compost placed on the final bay. This material is added to the topsoil and then dug back into the site’s grounds.

Also included in the school’s composting process is the wormery, a worm composting system created from recycled materials. The wormery has different layers. The bottom layer is for baby worms, the middle layer helps break down materials like shredded paper and coffee grounds, and the top layer is where worms turn peelings and vegetable material into worm castings. This top layer is then added to the compost to help fertilise the plants on site.

100 per cent sustainable fertiliser production and successful rainwater harvesting project

Since April 2023, Yarrells School effectively harvests rainwater with SUEZ-provided recycled water butts, eliminating the need to buy compost and fertiliser by producing enough for their extensive grounds. The introduction of internal food waste bins, also recommended by SUEZ, ensures that kitchen leftovers like vegetable peelings are now clean enough to be composted. The school’s thriving Eco-Committee continues to improve the school’s sustainability.

According to Yarrells School Estates Manager Eddie Hayes, "Producing our own compost and fertiliser has saved the school a fair bit of money and we have already seen the return on our investment."

Around 2,000L of rainwater is now harvested per week. The school cultivates its plants, vegetables, and extensive grounds using 100 per cent of their own fertiliser.