Food Waste Composting Pilot
Help turn food waste into useful compost and shape a food waste recycling service for the Isles of Scilly
You are invited!
We are inviting households to help trial a community run system that recycles food waste into compost. The composting pilot is run by volunteers from Salakee Farm and Isles of Scilly Community Venture.
Food waste will be processed in a biodigester near Salakee Farm on St Mary’s. The biodigester is an in-vessel composter which works like a closely controlled compost bin.
It uses an aerobic method to break down food waste, maintaining a high temperature while regularly turning over the material to ensure that food waste is safely treated. The process is continuously monitored to make sure that everything is running safely and as expected.
Why take part
The composting pilot aims to:
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Reduce the amount of food waste going into black bags
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Help produce locally made compost for gardens and allotments
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Test an on-island solution designed for the scale and seasonal needs of the islands
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Better understand how much food waste is made by households on the islands
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Provide practical evidence that can inform future food waste recycling services
What taking part involves
Participating households will be provided with indoor and outdoor food waste caddies along with clear guidance on what you can put in them.
We’ll tell you how the pilot works in your area - this may be a collection outside your home or a nearby bring site. We will also let you know which day of the week is your food waste day before you start.
If you have a garden or allotment, we’ll be making some of the first batches of compost available for you to try out in the spring.
Register your interest
If you would like to join as a participating household, please fill in the contact form using the link below.
We will then let you know the next steps for taking part and provide other helpful information including collection arrangements and accepted food waste guidance.
Frequently Asked Questions
What is the purpose of the composting pilot?
The aim of the community composting pilot is to test a different type of food waste recycling process which has the potential to be feasible at the small scale required by the Isles of Scilly.
The core of the processing method is a biodigester installed inside a shipping container. It is capable of processing up to 1000 litres of food waste every 24 hours and operates 24/7 with continuous temperature monitoring to ensure food waste is safely treated. The food waste processed by the biodigester can be subsequently used to produce compost.
The pilot aims to operate the process for a period of time to get a better understanding of the practicalities of running the machine. This includes how long it takes to process a given volume, how it behaves with different food types and how much effort is required to keep it running smoothly. The biodigester is similar to a human stomach and can get upset! Too many fatty foods, too little fibre or a lack of variety all have the potential to cause issues.
By engaging the community and getting households involved in providing food waste to the pilot, it will also give us a better understanding of how much food waste gets generated on Scilly. This helps to provide a more concrete view of the food waste processing capacity required for the islands.
The key benefit of this approach is the ability to increase scale in smaller increments compared to standard commercial implementations to align with the local demand. If there is a need for more additional processing during the season to handle commercial waste, this method provides the option to run an additional biodigester during the summer to meet that extra demand.
Who is going to run the composting pilot?
The composting process will be run by volunteers from Salakee Farm and Isles of Scilly Community Venture.
How will food waste be collected for the composting pilot?
The proposal is to setup bring sites in participating workspaces where domestic food waste can be dropped off or have a kerbside collection depending on the area.
Participating households will be told which collection method is operating in their area and which day of the week is their food waste day before you start. Participating households will be provided food waste caddies and guidance on what waste can be included.
Where is the composting pilot going to be located?
The site where the composting will occur is near Salakee Farm on St Mary’s.
Who is paying for the composting pilot?
The pilot is part of a programme of work funded by the Isles of Scilly Seabird Recovery Project to inform a potential eradication of rats from the off-islands of Scilly.
The expectation is by collecting and processing food waste separately from other waste, it will reduce the amount of food waste that can act as a potential food source or harbourage for rats.
Why isn’t the Council composting food waste?
The Council has come a long way in its waste and recycling journey, with significant investment and improved recycling services. Recycling has increased across the islands from approximately 25% (2018-2019) to approximately 40% since the introduction of kerbside recycling was introduced.
The Simpler Recycling policy implemented under the Environment Act 2021 requires the separate collection and processing of food waste by local authorities – but the Isles of Scilly are exempt and therefore the Council is not in receipt of Government funding to deliver separate food waste collections.
The Council’s Waste Reduction Strategy recognises the unique challenges in managing waste on the Isles of Scilly and seeks to encourage the reuse and recycling of materials to reduce the amount of waste produced across the islands.
The Waste Reduction Strategy also recognises the cost to deliver waste and recycling services on the islands, with a focus on working with partners to identify initiatives and measures that are sustainable and affordable with a greater emphasis on delivering on-island reuse and recycling schemes.
The Council, as part of its work to reduce waste, is scoping options and the costs associated with delivering a food waste collection service on the islands.
What are the Council plans around food waste collection?
The Council’s Waste Reduction Strategy has specific actions and targets in relation to increasing the amount of waste that is recycled or composted. These include expanding the range of materials available, delivering initiatives with partners to increase on-island reuse and recycling and to provide safe, efficient, cost-effective and reliable services which meets the needs of the community.
Establishing a kerbside food waste collection service is an action which has been developed as part of the Climate Change Action Plan (2022). The Climate Change Action Plan also mentions the reduction of waste through reuse opportunities on the islands as part of the Council’s organisational plans to achieve net zero carbon by 2030.
There are currently no published timelines on when kerbside food waste collection will be introduced by the Council. Prior to implementing food waste collections, there would need to be a robust plan for funding the scheme and how and where the food waste would be processed.
To summarise, while the Council intends to introduce kerbside food waste collections, it can only proceed once there is an agreed and funded plan for food waste collection and processing. Through this pilot scheme, the Council is working in partnership with Community Venture to explore and assess opportunities for on-island composting capacity, which could support the future delivery of food waste services across the islands.
Why not send food waste to the mainland for processing?
Sending food waste to the mainland is a possibility depending on the results of the pilot and local composting.
It is more beneficial from an ecological perspective to recycle food waste on the islands. Using food waste to produce compost locally provides a valuable and in demand product to the community while reducing the amount of energy used on transporting waste to the mainland.
The pilot will help get a clearer understanding on how much food waste can be realistically processed on the islands themselves, and how much potentially remains that may need to be sent to the mainland.
To summarise, sending food waste to the mainland is a possibility but it is preferable, where possible, to recycle as much food waste as possible locally.
Why is processing food waste on the islands difficult?
Food waste processing using the same type of machinery and facilities as the mainland (commonly Anerobic Digestion Plants) is only cost effective at large scale with a wide catchment area.
Many of the costs related to food waste processing are fixed or less impacted by the amount of waste processed. As food waste processing volumes increase, those fixed costs are spread over more tonnes, reducing the cost per tonne. Fixed costs include the essential groundworks, facilities and equipment to safely process the food waste in line with regulations, along with the staff to run the facility itself.
Wider catchment areas provide a reliable feedstock for a processing facility, allowing it to operate consistently throughout the year. This makes better use of machinery and equipment which lasts longer when used in line with design capacities. The Isles of Scilly have a more seasonal food waste pattern, with significantly less food waste in the off-season when holiday lets and hotels are not operating.
To summarise, to operate an Anerobic Digestion food waste processing facility on the islands similar to those the mainland is difficult as the volume on the islands is far below the scale needed to make it economically feasible.
What are the benefits from processing food waste on the islands?
Processing food waste on the islands would reduce the amount of waste that needs to be transported to the mainland and provide locally made compost. Processing food waste on the islands instead of storing and transporting it to the mainland will also help to reduce rats by removing an accessible source of food that attracts and supports them. Proper processing also reduces smells and the amount of waste left exposed, making the area less attractive to rats.
Based on 2022-2023 figures, it is estimated that between 600 to 800 tonnes of residual (black bag) waste was transported to the mainland by the Council. Taking the UK average of 88kg of food waste per person, that amount could be reduced by 180 tonnes annually, potentially resulting in cost savings.
The compost produced as part of the process is in high demand locally for gardens, allotments and farms. This would help to reduce the amount of compost that must be shipped over to the islands and reduce carbon emissions generated by the transportation.
Another potential benefit could be bringing more awareness to food waste on the islands. The separation of food waste from other residual waste could help residents and businesses to better understand how much they generate and could potentially save by reducing it.
To summarise, processing food waste on the islands would reduce the cost of waste disposal, provide compost for local consumers and increase awareness of the food waste problem.
What is being done to reduce food waste itself?
The pilot will not directly reduce food waste, but participating households separating food waste will gain a better understanding of how much food waste they produce. This is expected to help them to identify their largest sources of waste and potential reduction options.
The pilot will be weighing the food waste provided to calculate the average food waste per household. This will provide more accurate information on how the Isles of Scilly compares to the rest of the UK with regards to food waste.