Case Study Source: The Joint U.S.-Brazil Initiative on Urban Sustainability, part of the U.S. Environmental Protection Agency.
The Gramacho Landfill was receiving over 3 million metric tons of waste per year until 2012, producing at its peak 119 million Nm3 methane (normal cubic meter CH4) through decomposition within the landfill, which represents both a contribution to global climate change and a loss of a potential low-pollution energy source. Through a plan to install a methane capture system throughout the landfill, Novo Gramacho Energia Ambiental and Companhia Municipal de Limpeza Urbana (COMLURB) were able to leverage Clean Development Mechanism financing to reduce the climate change impact of the Gramacho operations and to create a potential income stream for these actors in the future, through sell-back of the energy to a nearby Petrobras facility. Currently, some of the methane captured is flared, which still reduces its total carbon dioxide-equivalent emissions; however, a purification system and a pipeline present an income-generating opportunity for the landfill and private investors that further decreases the climate change impact of the landfill and increases its economic value.
To create a sanitary landfill with a biogas capture system, COMLURB enclosed exposed waste and installed a better drainage system with impermeable barriers. The core of the biogas project required the installation of methane "wells" during the landfill upgrade process, allowing flaring and connection to the larger system and purification technology. Collecting and treating leachate has been an important part of this project, improving local environmental conditions. This effort complements a mangrove reforestation project, protecting the neighboring Guanabara Bay from pollution. As part of this project, the concession required a yearly set-aside for the recuperation of the surrounding low-income community and capacity building for the waste picking community. This funding will allow the pickers to retrain in the formal recycling industry after the landfill closes.
Environmental, Social, and Economic Benefits
This project is projected to create the following benefits:
- 5.96 tons of CO2 emissions reduced
- 90 million Nm3 of usable biogas produced on average over 20 years
- $232 million in value of CH4 emissions avoided (carbon credits)
Companhia Municipal de Limpeza Urbana