Feature: Ever wondered what happens to the food waste in your St Albans recycling caddie?
PUBLISHED: 17:00 12 August 2018
©2018 Danny Loo Photography - all rights reserved
Anosmia, the inability to smell, is not normally something I would be gagging for.
But that all changed the moment I entered the Agrivert North London Anaerobic Digestion (AD) Facility in London Colney, and the inescapable stench of rotting food hit the back of my throat.
The Herts Advertiser had been invited on a tour around the food waste recycling plant to witness first hand what happens to all the gunk collected from food caddies in St Albans.
I should not have been surprised by the smell - the building processes a whopping 50,000 tonnes of solid and liquid wastes every year and 140 to 200 tonnes of former edibles is dropped off at the plant each day.
Lorries carrying slop to London Colney come from households in Hertfordshire and Essex and businesses in St Albans, but Agrivert work country-wide with more than 41 local authorities and have five AD plants.
Trying to quell my stomach, which probably should have run away to the circus it was backflipping so hard, we are taken into the reception area.
This is where all the rotting mush is collected together into a ‘soup’, separated from any contaminants like plastic bags, and whizzed over to the 16.5m digestion tanks.
What happens next is similar to the biological process inside all of us when we eat food.
Heated micro-organisms eat away at the decomposing food for about 75 days, giving off methane which is burned to turn a generator and make renewable energy.
The decaying mulch is constantly stirred to stop a crust forming during the process - a vile image for someone too ridiculously squeamish to drink milk with a skin (me).
Treating the soup for so long creates a high quality fertiliser product, commercial and planning manager Andrew Simm assures us, and is therefore more attractive to farmers around the county.
After about two and a half months it is then pasteurised and turned into biofertiliser called digestate.
Environment portfolio holder at St Albans district council (SADC), Cllr Frances Leonard, was upbeat - forcing me to come to the conclusion that she is better at hiding repulsion than the rest of us: “Now you’ve been to see the plant you can see what fantastic use can be made of our waste food.
“None of us want to waste food but unfortunately it is an inevitable from time to time and I am very impressed by the facility and how they extract all the stuff they don’t want.”
Agrivert AD plants are treating wastage 24 hours a day, seven days a week, every week of the year. Even a lightning strike to an Oxfordshire Agrivert digester tank in June did not stop operations altogether.
Andrew said: “These sites provide a cost effective and sustainable solution for local authority waste and commercial customers for unavoidable food waste.
“They play a vital role in treating the country’s food waste generated. As a company, Agrivert prides itself on its high level of availability and its continual electricity production.”
Energy generated in the Agrivert process in London Colney can cover 6,000 local homes and offset 89,000 cars.
The power produced is more reliable than other renewable energy sources, as solar panels or wind turbines rely on the unpredictable British weather.
Just before I am about to leave and again experience fresh air, I’m informed that only the day before the Agrivert North London AD Facility had won the Best UK Food Waste AD Plant at the AD and Biogas Industry Awards Ceremony 2018.
And no wonder. Before this visit, I’m ashamed to admit I would halfheartedly throw eggshells into the food recycling caddie - but it was lacklustre.
But I am converted. I’ve turned into that annoying person that unashamedly tuts when someone doesn’t scrape their leftovers into the food recycling and glares when mouldy bread is tossed into the black bins. It is such a tiny change - throwing food from your normal container into a different container - but can make such a huge difference overall that it is a no-brainer, right?
To find out more about the London Colney plant, visit www.agrivert.co.uk
To find out more about the weekly food waste collection in St Albans, visit www.stalbans.gov.uk/environmentandwaste/rubbish-waste-and-recycling/bincontents/FoodWaste.aspx