New solutions for managing food waste wanted

Thursday 28 April 2022

Guernsey’s food waste could be treated locally in future instead of being exported for processing - if a suitable solution can be provided on-island.

Guernsey Waste is now inviting initial expressions of interest from any parties who would like to receive the island’s food waste when the current processing contract expires at the end of 2023.

Those interested have until midday on Monday 23 May to submit an expression of interest. Formal tenders will be invited later this year, and a contract is expected to be awarded before the end of the year for an anticipated start date of January 2024. 

Any change to the current export arrangement and processing will require approval by the States. However, Guernsey Waste Operations Manager Sarah Robinson, said this does not rule out other treatment options being considered if they can demonstrate environmental benefits and value for money. 

More than 4,500 tonnes of local food waste is collected every year from homes and businesses. Currently, following processing at Longue Hougue, this material is exported to a facility in the South of England. 

It then undergoes treatment through a process known as anaerobic digestion. Micro-organisms are used to break down the food and produce a gas that can be burned to generate heat and electricity or used as vehicle fuel. It also produces a nitrogen rich fertiliser. 

“Anaerobic digestion is widely considered to be the optimum treatment for food waste, because it will recover valuable energy from the material, as well as other useful bi-products,” said Ms Robinson.

“However, we are very open-minded at this stage and are keen to hear from operators or potential operators that could provide a solution for managing the island’s food waste."

Pictured: More than 4,500 tonnes of food waste is collected in Guernsey each year.

“If we have proposals for any other forms of treatment, then we can evaluate what benefits they might offer compared to anaerobic digestion,” continued Ms Robinson. 

When the island’s waste strategy was first approved in 2012, it included plans for an on-island facility for treating food waste, using anaerobic digestion or a similar process. This was subsequently replaced by the current export-based solution, mainly due to the high cost to the States of constructing a local plant at that time. 

Miss Robinson stated that whatever treatment is used will have to be reliable, with contingencies built-in to ensure continuity of processing. It also has to be flexible since Guernsey’s waste strategy is focused on prevention and reduction of waste. 

The processor will be responsible for ensuring there are adequate outlets for any biproducts from the processing. 

In the case of anaerobic digestion, these are generally liquid and solid residues, which can be used as nutrient-rich fertilisers  However, this could be restricted in Guernsey due to the limited land available and the potential impact on the water catchment, and may therefore require further treatment. 

The island’s Waste Management Plan sets out the methods that can be used to treat and process different waste materials. 

Changes can be agreed by the States, provided it can be demonstrated that an alternative method is able to achieve the optimum environmental benefits at a reasonable cost, which is a legal requirement.