Using Informal Settlements as Urban Laboratories for the Perfection of Biogas
- Aug 19, 2019 7:45 pm GMT
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When I was an undergrad in architecture school in Bogota, informal settlements was a constant topic of worry for various reasons: they are in environmentally protected areas, in high-risk areas, the existence of criminal entities known as “tierreros” , who fraudulently sales district land and finally the legalization and the upgrading of these settlements are costly for the district’s administration.
According to 2017 calculations, the total legalization cost for 214 neighborhoods would amount to a total of $47.2 million US. The upgrading would cost about $200 million US costs for the aqueduct, sewage, gas, main roads and backroads that connect the settlements with the center of the city.
More than 21% of Bogota’s urban land are informal settlements occupied by appropriation or fraud. Bogota is divided into 20 jurisdictions called localities and 13 localities have informal settlements. One of the localities most affected by illegal settlements is Ciudad Bolivar, with a total of 7,296 occupations (or households).
I created a proposal for Ciudad Bolivar to test and perfect biogas, a renewable technology produced from the decomposition of organic waste such as food scraps and human and animal waste. The objective was to find an alternative solution to traditional upgrading, since Ciudad Bolívar’s topography is 90% mountainous, making the upgrading more expensive and time-consuming to build. I chose biogas due to its versatility and its ability to minimize waste and making the most of resources, aiming for a circular economy. Waste, whether it be from food scraps, grass clippings or from sewage, can be converted into electricity, heat, gas or fuel, through anaerobic digestion. During the process, it produces digestate, a byproduct from anaerobic digestion that can be converted into fertilizer, soil amendments or livestock bedding.
In summary, the project uses decentralized aerobic digesters to produce energy to be used for urban lighting of the area, and where the digestate was made into soil amendments marketed and sold to the predominant agricultural sector in the area. This gave the opportunity to create jobs for residents of the locality in the production, processing, and distribution of digestate. Because the project had a mitigating effect on greenhouse gas emissions, it was perfect to sell carbon bonds, a market-based tool to limit GHG.
With a careful analysis, I have identified limitations for this project to be implemented in reality:
There are no standard regulations or guidelines for trash pick up among operators of waste. A standardized trash collection system from the micro to the macro needs to be created, for better production of biogas. The means a clear classification system from compostable material from non-compostable material.
Underdeveloped biogas technology. There need to be collaborations between countries who have implemented biogas in an urban setting, such as Switzerland, to gradually adapt to Colombia’s needs.
Strong communication network between the local government and the residents of the area. Informal settlements are remote and difficult to access, so the local government needs to hire residents as surveyors, educators, and communicators of the project to get accurate feedback from residents.
Analysis of land use and zoning laws for the implementation of renewable energy projects. At the moment decentralized anaerobic digesters are viable, but the construction of a facility is not possible.
Keeping in mind the existing policies, technology, and institutions for the professional development of the existing workforce, for the successful development of the implementation of biogas, there need to be 6 phases for biogas to develop in Colombia.
Phase 1: Legislation
Phase 2: Plastic-free pledge
Phase 3: Prototype biogas
Phase 4: Co-creation period
Phase 5: Implementation
Phase 6: Carbon economy