August 2, 2007
By Emily Visser
THE City is investigating ways of using Johannesburg's full landfill sites, turning the waste into electricity-producing energy.
Already 33 sites have reached their capacity and have been closed, although a number of these are old ash dumps and are not fully fledged landfills.
Some of the closed sites have been rehabilitated and turned into green belt areas. Now the City's department of infrastructure and services and Pikitup have earmarked others for a gas-to-energy project, using the methane gas that forms when organic waste decays, and so providing Joburg with green energy.
Six closed landfill sites – Meredale, Waterval, Kya Sands, Mapetla, Meredale, Panorama - and the four operational ones - Robinson Deep in Springfield, Goudkoppies in Devland, Ennerdale in Lawley and Marie Louise near Dobsonville - are being considered for the project, according to the company's disposal executive, Neville Smith.
Robinson Deep and Marie Louise are high-intensity landfills, with almost 2 000 tonnes of waste delivered each day. Goudkoppies and Ennerdale accept 1 200 and 700 tonnes a day respectively.
Tapping into gas-energy
Opportunities created by the Kyoto Protocol and the United Nations framework convention on climate change mean that developed countries can implement greenhouse gas mitigating projects in developing countries in exchange for carbon credits.
The Pikitup gas-to-energy project will fall in line with this protocol and is currently out on tender.
"A preferred service provider will be appointed to initiate the turnkey project, [entailing] a feasibility study, planning, design, construction and operations with agreed-upon, guaranteed revenue flows to the city," explains Themba Camane, the executive director of infrastructure services.
In addition to all technical requirements, the national Department of Minerals and Energy (the designated national authority) must be satisfied that the project will hold sustainable benefits for the environment.
Landfill gas (LFG) consists of about 50 percent methane (CH4), the primary component of natural gas, and about 50 percent carbon dioxide (CO2), with a small amount of non-methane organic compounds. As a greenhouse gas, methane is 23 times more potent than carbon dioxide.
With the project "Johannesburg is a step further towards using green energy", Camane says.
Instead of allowing the gas to contribute to current greenhouse pollution, the project will tap into green energy solutions such as electricity generation and direct-use projects.
A study by the US Environmental Protection Agency in 2001 found that approximately 30 percent of the human-induced greenhouse effect can be attributed to non-carbon dioxide greenhouse gases.
Managing landfills
Creating and operating a landfill is a complicated process. It requires in-depth study of the geology of the site, the effect on and proximity of the land to residents, the depth of the water table in the area and the existence of available infrastructure.
"All landfill sites are managed within the context of the legislative requirements imposed by the Department of Water Affairs and Forestry," Smith confirms. Permits are issued by the Department of Environmental Affairs and Tourism and landfill sites are developed according to the specific permit requirements.
The high density landfill of Robinson Deep
"[Permits] are guidelines for how you manage the landfill for the duration of its life."
In addition, a permit will not be issued until an environmental impact study has been completed. Six-monthly reports on air quality and water surface quality are compiled as a standard monitoring practice.
"Reports show the levels of chemical substances and what corrective action should be taken." Audit reports on environmental management and the health and safety of people working at the landfill are done regularly.
Most landfills start off with some excavation and the site is progressively filled in strips, "layers of cells, called berns" which are usually spread 30 metres across.
"The minimum ratio is three parts waste to one part soil cover." Waste is compacted and covered with either topsoil, if this is available, or builder's rubble to eliminate smell and rodents. Permits also determine the height of landfill sites.
Six landfill sites in Soweto have been rehabilitated into parks and turned into public open spaces; the Panorama site was developed into a composting plant and environmental centre; Linbro Park has an equestrian centre, consisting of horse trails and "subject to capital funding, a composting plant and environmental centre will further be erected".
New landfill
Following the closure of the Linbro Park landfill site in the north of Johannesburg after it reached its capacity, it has become necessary to develop another site to service the northern parts of Johannesburg.
"There is no landfill site in the northern parts of Johannesburg, which means waste has to be diverted to other sites at great cost to Pikitup," Camane says.
An amount of R1,4-million has been allocated for this financial year to secure future landfill space.
There has been public resistance to a new landfill on the Northern Works site near Diepsloot and Dainfern as residents feel that it is too close to their homes.
The first step began in June 2000, with the identification of nine areas as potential sites; Northern Works was identified as the most suitable. The sites were compared according to key economic, environmental and socio-economic criteria at that time.
"The Gauteng department of agriculture, conservation and environment – the environmental impact authority – has requested further environmental impact studies [for the site] and additional public participation."
Only once all legal and public processes have been completed satisfactorily and subject to further official recommendations, will the national Department of Environmental Affairs and Tourism issue a permit for the landfill to be created, Pikitup environmental engineer Mzu Tshem explains.
Decreasing waste to landfills
Of the 1,4 million tons of waste generated each year in Joburg, Pikitup collects 1,2 million – the rest is illegally dumped. One person generates 1,6 kilograms of waste a day, a Pikitup business plan study found in 2005-06.
"Waste is growing substantially. We really need to think of how to reduce, minimise waste upstream – packaging, marketing materials, recycling at source and how to manage these waste streams."
Cleaning up illegally dumped waste costs Pikitup R70-million a year, with 80 percent of it consisting of builder's rubble.
Composting of garden waste can take up to 15 percent out of the overall waste stream, "but at high cost of capital and long payback periods [on investment]". There is only one Pikitup composting site, situated at Panorama.
"Builder's rubble will decrease 20 percent of the waste stream if it is directed towards crusher plants," Tshem says. A feasibility study has been completed to create a builder's rubble site. Further developments are dependent on obtaining the necessary capital.
Goudkoppies reclamation
Pikitup is particularly proud of the reclaiming project it has successfully completed at Goudkoppies landfill.
Over 200 shacks had to be removed from the site because it posed serious health and safety risks to the people living on the site who eked out a living from waste reclaiming. Consistent engagement with the illegal occupants resulted in them voluntarily demolishing informal structures on the landfill.
Pikitup is rationalising the reclamation taking place at the site. "Only a certain amount of people will be allowed to do reclaiming on landfill sites. Reclaimers will be registered and will have to adhere to safety and legal requirements."
Bluebag project
The bluebag pilot project – a recycling-at-source project introduced in Lonehill - is proving very successful, with "recycling at 23 percent" of the total waste in the area, says Christa Venter, Pikitup's special projects manager. Paper recycling alone increased by 20 percent over the last quarter.
"The only problem we have with the project is that people are complaining about buying the blue bags." The bags cost 50c each or about R2 a month. However, Venter is looking into getting sponsorships to carry the costs of the bags.
Pikitup is doing a before and after survey in Yeoville (low income), Observatory (middle income) and Bryanston (high income) to assess the possibility of rolling out the project in these areas.
According to Tshem a number of approaches will be required to decrease waste streams.
"It means embarking on waste management projects. It is about being innovative, using available technology as well as disposing of waste as environmentally as possible."
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