Composting Green and Food Waste

• Introduction
• Styles of Composting
• Composting Tips
• Composting Vessels & Suppliers
• Green Waste Recycling Services
• Further Information

Introduction

On-site composting is the method of treating organic material near the source i.e. setting up a composting system on the property of the business. On-site composting of waste produced by offices, caterers, small businesses, hospitals, prisons etc is common in the US, but remains underdeveloped in the UK.

When deciding upon a method of composting for your business, you will need to consider a range of variables so that the right method is selected. Factors such as the cost of bins and equipment, geographic location, climate, source and amount of organic material to be composted, staffing, size of business, and surrounding land use need to be taken into account.

Once the decision to use on-site composting at your business has been made, there are four popular methods available to choose from. These methods are backyard composting, aerated static piles, in-vessel composting and vermiculture.

Off-site composting
If your business does not have room or time for on-site composting, consider companies which accept or collect green waste and garden waste such as tree trimmings and grass clippings. Please see the list of green waste recycling companies below.

Composting Styles

Backyard Composting
This method uses a vessel or bin outside your business. This option requires:

1. An outside area to place the bin.
2. An appreciable amount of work for maintenance. Material must be turned over on a regular basis to keep the process advancing at a steady pace.
3. A fairly strict mix of waste types, moisture and exposure to air to avoid problems such as odour. The flow of meats/dairy products to the backyard composter should be avoided.

BUT
The backyard composter has a low start-up cost and is ideal for business with a large outdoor space and employees willing to provide the needed maintenance. The end product of composting is ideal for landscaping around the business or giving to employees/customers.

Aerated Static Pile This is a more advanced version of the backyard composter. The unit has a blower fan and an air distribution system which eliminate the need for an individual to physically turn the compost. This system requires:

1. Coarse materials. Fine or overly damp material will prevent proper circulation of air. To promote a uniform rate of composting, compostable waste should be mixed with a bit of bulk material (such as sawdust, mature compost, peat moss or leaves).
2. Monitoring of the moisture content and temperature.
3. To be enclosed or covered to provide better control of moisture and temperature.

BUT
The installation of an aerated static pile costs more then the backyard composter, however, less maintenance time is needed to tend to the unit.

In-Vessel Composting There are two versions of in-Vessel composting systems; batch and continuous flow. In-vessel systems are able to balance the optimum carbon, nitrogen, oxygen, water and temperature levels and are highly automated systems that shred, mix, aerate, water and unload automatically. This system requires:

1. High initial set-up cost for the technology.

BUT
This set up makes in-vessel composting suitable for urban areas with land restrictions and where there are concerns over odour and maintenance.

The main advantage of the in-vessel systems relate to the speed of the composting process and the control maintained over key composting variables (i.e moisture).

Vermi-Composting
Vermi-Composting, or vermiculture, is the addition of worms to the composting process. Vermiculture uses a specific kind of earthworm, the red wiggler, because of its ability to survive and adapt to sudden changes to its surroundings. Once a bin is obtained, it will need some bedding material such as peat moss, leaves, and saw dust. Worms are added to settle in this material, and organic waste can be added by burying it into the soil. Meat and dairy products should not be added to the vermi-composting unit. This system requires:

1. A small amount of maintenance because food scraps must be buried under the soil, the bedding must be changed every four months and the compost extracted at that time.

BUT
Also requires the addition of worms to the composting process to help both speed the process up and make it suitable for indoors. Worms will also work all year round in an outdoor composter.

Composting Tips

The following tips apply to successful maintenance of all types of on-site composting:

1. Compostable materials need to be properly segregated from other materials. Train employees in the source separation of food waste in the kitchen/lunch room and the compost operations.
2. Food waste fed to a composting unit must be free of contaminates like heavy metals and non-compostable materials.
3. Breaking up organic material helps it to compost at a faster rate. To speed up the composting process, add organic material in small pieces.
4. Make sure the circulation of air is not a problem in your composter in order to avoid odours.
5. For every amount of food waste, add a small portion of 'brown waste'. Brown waste can be leaves, straw, hay, woody material, paper, egg cartons, toilet paper rolls, cereal boxes, cardboard, etc.
6. Keep a record of how much waste you are composting/saving (e.g. 1 bin bag of waste rather than 2 each day), and use positive results to promote the image of your business and maintain enthusiasm amongst employees.
7. What NOT to compost: Meat, fish, bones, whole eggs, fats and oils, dairy products.

Composting Vessels & Suppliers

Green Waste Recycling Services

What is green waste? Green waste is generally considered to be waste consisting of plant matter, however the definition of what counts as green waste sometime varies between organisations. Not all green waste recyclers will take all types of green waste so check with them beforehand for exactly what they will accept.

Further Information

Oxfordshire County Council Home Composting Leaflet - Introduction to composting at home.

Back to top