Author: Suzanne Longmuir – Certification Europe, Waste Enforcement Officer
Welcome to another blog on compost! Previously, Will Mitchell expertly covered the benefits of compost and home composting (if you missed it, you can check it out here: Ultimate Guide to Composting in Ireland) so, to mix things up a bit, I’m going to focus on regenerative agriculture and industrial composting (basically what happens to the contents of your food bin).
Just in time for International Compost Awareness Week!
If you’re not into the compost scene, I’m sure you’re wondering what International Compost Awareness Week (ICAW) is! Well, it happens to be the largest education initiative of the compost industry and it is celebrated worldwide each year during the first full week of May. The main goal of ICAW is to raise awareness on why we should be composting our organic waste and using compost on our farms and in our gardens.
The 2022 theme of ICAW highlights the benefits of regenerative agriculture – a really cool concept that focuses on recycling carbon and nutrients back into the land to support ecosystem health, mitigate climate change and support farmers through producing more reliable yields. A win-win situation!
Image source: International Compost Awareness Week Poster 2022 (compostfoundation.org)
When compost is added to farmlands, gardens and other landscapes, it provides food and nutrients for soil microbes. These microbes enrich the soil and help to remove carbon from the atmosphere through a process called photosynthesis. So, in summary, when we put our food scraps and garden cuttings in the food bin, we are creating compost that, when added to soil, helps to make our food more nutritious, reduces the need for fertiliser and improves the overall health of our climate. Anyone else feeling ‘Circle of Life’ vibes?!
So composting is the answer?
In some ways, yes, but we should always be mindful of how much waste we produce. In Ireland, we generate more than one million tonnes of food waste every year which represents a carbon footprint as high as 3.6 million tonnes of carbon dioxide equivalent (this represents over 8% of our overall emissions!) So, without wanting to sound too preachy, we should always try to prevent food waste first and use composting for the unavoidable food waste such as fruit peels, animal bones etc.
Due to the large emissions associated with food waste, compost collections are a key part of Ireland’s environmental targets. Food waste that is not composted is sent to landfill where it releases methane gas as it degrades (methane is 25 times more potent than carbon dioxide – which is a big problem!). According to the Environmental Protection Agency (EPA), only 43% of Irish households have a brown bin for collection of organic waste. By the end of 2023, under the revised Waste Framework Directive, it will be mandatory for all households to have a separate bin for the collection of this organic waste.
There is also a significant amount of food waste not being segregated for separate collection and this can contaminate other materials that could have been recycled. An EPA survey in 2019 found that over 30% of businesses did not use a food waste bin despite a decade of legislation requiring same.
The compliance audits and waste inspections that we carry out in Certification Europe play a key role in ensuring bins are being used correctly, waste is being transported to the correct facility and facilities are dealing with the waste effectively. The ISO 14001 standard demonstrates an organisation’s environmental credentials and how they implement an environmental management system.
Image source: Food Waste Hierarchy – Environmental Protection Agency (epa.ie)
What happens to the organic waste we put in the brown bin?
As we all know, the trusty binmen take our household waste away as per the bin collection contract (there’s nothing worse than realising you forgot bin day!) The brown bin contents are taken to a large-scale composting facility which is designed to handle high volumes of organic waste. This is known as commercial or industrial composting. The facility will also be accepting waste from supermarkets, restaurants and other commercial outlets.
There are two main types of large-scale composting known as in-vessel composting and anaerobic digestion. In Ireland, most of our composting facilities work with in-vessel composting as it can process large amounts of waste and it can accommodate virtually nearly any type of organic waste (including meats, animal manure and biosolids).
Once the organic waste reaches the composting facility, it is processed to remove any non-organic contaminates. Any food wastes and nitrogen-rich materials are mixed in machines to create a sludge (nice!) Next, carbon-rich materials such as tree cuttings and paper are added to the sludge to create the right carbon-nitrogen ratio. The organic materials are then moved to a drum, silo, concrete-lined trench, or similar equivalent. The fact the waste is contained in a vessel means that the facility can control the environmental conditions such as temperature, moisture, and airflow. The vessel is usually kept at 70 degrees to speed up the process. Over the period of a few months, the material is mechanically turned or mixed to make sure it is aerated. This product can then be sold to farms, garden centres and plant nurseries and can be used in regenerative agriculture.
Littleton Composting is the biggest in-vessel composting facility in the Republic of Ireland, processing 45,000 tonnes per annum. The facility accepts non-hazardous biodegradable wastes from which it produces Class 1 quality compost, a valuable soil improver.
Image source: Littleton Composting Facility, Beauparc (beauparc.ie)
So, there you have it – a quick overview of what happens to the organic waste in your brown bin! The production not only reduces the emissions from landfill; it also produces a product that can be used to increase plant yields and take in carbon from the atmosphere. If you want more information on composting, you can visit ICAW website and even set up your own composting facility!
Read our guide to why should we care about environmental management.