Money down the drain – food waste disposals are bad for our sewers

The utility has raised concerns about their increased promotion following the introduction of the new waste disposal strategy.

Water quality manager Margaret McGuinness said: ‘Although considered by some as potential money-saving devices and possibly more hygienic than food waste caddies, macerated food and fat can combine in a customer’s own wastewater pipes, resulting in expensive blockages,’ she said.

‘More widely, they will cause more problems in the island’s sewer network.’

Mrs McGuinness said that the use of a food disposal unit in the kitchen sink might sound a sensible option, but food waste cannot be disposed of down the drain.

Following the maceration of food, fat can mass in the pipes, needing expensive blockage clearance, and increase the risk of foul flooding to downstream properties, as well as providing excessive nutrient-loading in the sea, which may impact on the island’s marine environment.

‘Our sewers need to be resilient in times of heavy rainfall and the loss of flow capacity caused by fats, oils and grease [known as Fog] can be significant,’ Mrs McGuinness said.

‘Even if the food is liquefied, the Fog in it congeals and binds to other solids in sewage, such as wipes, and risks blocking the sewer, causing sewage flooding and pollution.’

She said the utility was keen to ensure its operations do not have a detrimental impact on the water environment.

‘It is therefore important that customers understand the environmental impact of the way that they use water and help us to protect the environment by using water wisely and keeping Fog and other non-biodegradable products out of our sewers,’ she said.

‘We encourage customers to continue to be responsible when it comes to dealing with their waste. The only things that should be disposed of into the wastewater system are the ‘‘three Ps’’ – poo, pee and paper.’

Guernsey Water considers the free collection of food waste for the purposes of energy recovery a good thing and much more sustainable going forward.

‘We borrow water from the environment by collecting it from streams, storing it in reservoirs, treating it, supplying it to customers, collecting it again once it has been used, then conveying it to Belle Greve Wastewater Centre where it receives preliminary treatment before returning it safely to the environment again,’ Mrs McGuinness said.

‘This means we are responsible for the water cycle from source to sea and should be mindful of the impact our actions can have on it.’