'Black gold' from garden refuse

Cape Town – What began as an attempt to produce enough decent compost to have his export grapes classified as organic ultimately developed into a comprehensive additional business for Eddie Redelinghuys of Paarl.

In 1998 Redelinghuys began in earnest to make his own compost by shredding municipal garden refuse at a Durbanville dump site. This evolved into a business delivering compost to farmers throughout the Western Cape and even as far as Upington in the Northern Cape.

His compost business, Reliance Compost, has a three-year contract with the City of Cape Town effectively to convert 90% of all garden refuse in the municipal area into compost. This is a typical win-win arrangement that ensures Reliance of sufficient material for compost production, and the municipality saves on transport costs because not all of the garden refuse needs to be transported to dump sites, and there is less money and space required for extra waste dumps. Dumping refuse costs at least R150/1m³.

Municipalities across the country are struggling with the growing amount of refuse to be removed for safe, environmentally friendly disposal. Dumping sites quickly fill as a consequence of rising urbanisation. Reliance chief executive Detlev Meyer says by February the company had saved the Cape Town municipality 3.6mm³ of dumping space over the past three years.

This is sufficient garden refuse to completely cover 500 rugby fields.

The municipality has 22 sites for discharging garden waste, and Reliance has a contract to receive and shred it at 12 of these points. Six new businesses for the processing of refuse have been established, and these provide 50 people with jobs.

At these disposal points a machine shreds the garden refuse, thus reducing its volume by 75%. Instead of, for example, four loads, only one load is now required to remove the same amount of garden refuse.

The material is taken to Reliance’s compost farm near Klipheuwel where it is deposited in 75 rows, each 200m to 300m long.

Reliance uses a certified production technology called controlled microbial composting. The University of Stellenbosch helped to develop microbes which rapidly convert the shredded plant material into compost. As soon as a new load of garden refuse is offloaded it is treated with the microbes. Over the next six to eight weeks the pile’s temperature, moisture content and carbon dioxide is measured twice daily, and rotated a total of 22 times. Meyer explains that the temperature of the compost should not rise above 65°C or the microbes would be killed by the heat.

After six to eight weeks the compost is ready and delivered to farmers and landscape architects, as well as to golf courses and bowling greens, nurseries and individuals. About 10 000m³ to 15 000m³ of compost is produced every month.

The general rule is that around 8m³ of garden refuse shrinks to 2m³ of compostable material once it is shredded, and this eventually becomes 1m³ of compost.

Reliance has been earning carbon credits since the business was registered for earning voluntary carbon credits in terms of the United Nations Framework Convention on Climate Change rules in May 2008.

Reliance annually earns around 80 000 carbon credits - calculated according to the tons of less greenhouse gas emitted as the garden refuse does not lie and decompose in dump sites. Reliance is registered to sell 60 000 credits a year on the open market. The remaining credits ensure that Reliance is itself a carbon-neutral enterprise. In 2010 the company was one of only three businesses globally approved to help expunge the carbon footprint of the World Cup soccer tournament teams.

Through sports equipment manufacturer Puma Reliance helped make seven of the teams carbon-neutral.

This means if a team, for instance, releases 100 tonnes of greenhouse gas in the process of participating in a tournament, they have to buy 100 carbon credits to mitigate the effects of their carbon footprint. The well-known red open-roofed touring buses in Cape Town, for example, also buy Reliance’s carbon credits to mitigate their exhaust emissions.

According to Meyer, Reliance hopes to enter into similar agreements with other municipalities in the Boland, George, Bloemfontein, Tshwane and Johannesburg, so that it can similarly process garden refuse on a grand scale.

 - Sake24

For more business news in Afrikaans, go to Sake24.com.