Looking at the case of Mexico City, poor waste policies are a threat to public health and the environment. Yet it has plans to solve its problem, by affording the rights of the Bordo Poniente landfill site to BMLMX Power Company. They plan to build a biogas plant on the landfill site, converting the majority of the waste into usable biogas. A recent development pans to use the biogas to light the streets of Mexico City. Not only will this drastically reduce the amount of energy used, but will reduce the levels of carbon dioxide each year
“It is estimated that a reduction of around 1.4 to 2 million tonnes of greenhouse gas emissions can be achieved during the first year of biogas utilisation,” says Menéndez-Garza.
Biogas is essentially created by using anaerobic decomposition on all organic substances in landfill waste. Landfill restoration must prevent greenhouse gases from migrating into the atmosphere while avoiding smouldering fires, therefore gas must be extracted under controlled conditions. Perforated tubes are drilled into the landfill body and connected by a pipework system. Using a blower, the gas is extracted from the landfill.
So turning landfill into biogas is a very viable and sustainable way of managing waste. In particular with the case of Mexico City, where the waste management is already dire, it allows the City to profit of waste. However the inorganic waste must also be addressed.
Mexico City Government’s have made an agreement with CEMEX – the world’s largest building materials suppliers and cement producer – to deliver up to 3,000 tonnes of solid waste inorganic fraction (SWIF). SWIF is separated from materials that can be immediately recycled (e.g. aluminium and glass) or otherwise these materials would add to more landfill.
Therefore the processing of SWIF decreases the amount of material going into landfill. This prolongs the life span of existing landfills and means the creation of new sites can be avoided. Reports argue, that even fuel spent in transporting the SWIF, has a lesser impact on the environment, than if they were sent to landfill.
Unfortunately, the closure of the landfill site has caused some unusual problems. Individuals claim, that the closure has destroyed and entire community that has based it self in salvaging parts from the landfill. It seems there are some in Mexico City, that have a strong will to recycle.
But the magnitude of the problem the landfill has reached, vastly outweighs any recycling effort. Given all the benefits of converting the waste into natural energy, and trade, this is by far the best option.
Now Mexico City creates 12,500 metric tonnes of municipal solid waste per day. It has reduce the amount going to landfill to 5,500 tonnes, in order for it to be sustainable. Through the proposed recycling programme, 1,023 tonnes of waste will be converted into energy. 507 tonnes will be turned into compost. These are the necessary changes Mexico city needs, to being a more sustainable path. It should learn from its past; recycling is the key to avoiding such crises. Educating people to be mindful of their organic waste, is an assured way to prevent future problems from occurring, but strong government policies will be key.
Michell. G, 18th January 2013, ‘How Mexico city turned garbage into fuel’. Available on: http://cities-today.com/how-mexico-city-has-turned-garbage-into-fuel/