Chennai's long-standing waste management issues had one last hope for decentralised management in the form of Micro Composting Centers (MCC) and Material Recovery Facilities (MRF), which were at least imperfectly functional. However, the recent announcement by the GCC regarding the closure of MCCs has prompted questions among sustainability allies, potentially linking the decision to its promotion of waste-to-energy plants.
The Greater Chennai Corporation (GCC) recently passed a resolution to close 168 out of 199 Micro Composting Centers (MCCs) and 88 out of 137 Material Recovery Facilities (MRFs). These facilities play a significant role in managing both biodegradable waste and non-biodegradable waste collected from residents. The decision was apparently driven by grievances from residents concerning stench and health-related issues. As a result, the city’s biodegradable waste, over 500 tonnes, is now being diverted to the city’s WTEs, ending up as smouldering heaps in the city’s dump yards.
Picture 1 - Ward 63 composting facility in Pudupet, Chennai ICAGI
Do the GCC’s Micro Composting Sites deserve the derision shown by its neighbourhood residents? Are they really cesspools of stench and maggots? CAG has previously audited the state of some MCCs (results not published) and we can confirm from our visits that there is truth in this assessment. We have also previously written about how well maintained MCCs are a world apart from some of the poorly run ones.
This article looks at various factors that lead to communities complaining about MCCs in their neighbourhoods, and proposes practical solutions to address the issues.
All it takes is minor tweaks
Aeration: The primary focus of composting units should be planning for proper aeration in the composting heaps. This can be achieved through regular turning of the compost or by adopting open windrow composting methods, involving tilling over the compost heaps.
Challenges for proper aeration: GCC’s concrete-built composting pits present significant challenges for conservancy workers, making it difficult to access and navigate through the pits to turn the compost due to their unfriendly design. For example, pits observed in zones 4, 8 and 15 are too high to allow easy access. This design makes it particularly difficult for female conservancy workers who have to climb the pits and turn the compost over, often resulting in improper turning of the compost, causing setbacks.
Dry wet or C&N ratio: Another important factor affecting the environment of the compost piles is the carbon-to-nitrogen (C:N) ratio, which refers to the balance between dry and wet content in the compost. The ideal C:N ratio should be maintained at 25:1. Excess moisture or nitrogen can lead to strong odours, while insufficient nitrogen content can stall the composting process entirely.
Challenges for balancing the C&N ratio: GCC’s composting units in Arumbakkam, Porur and Kannagi Nagar also have a design problem with how their outlet pipes are sited. These pipes, which are intended to discharge excess leachate water from the composting pits, are slightly elevated above the ground. This design flaw exacerbates the odour problem, leading to leachate stagnation at the bottom. This stagnation not only hampers the composting process but also contributes to the generation of foul odours.
Picture 2 - A composting center in Porur (now demolished) with elevated leachate discharges ICAG
Segregation and community awareness - Segregation is essential for achieving odour-free composting. Properly separating biodegradable waste, such as fruit and vegetable peels and food scraps, from non-biodegradable waste like plastics or hazardous substances allows the composting process to proceed efficiently. This separation prevents contaminants from interfering and causing foul odours. By ensuring the right balance of materials in compost heaps, segregation promotes smoother decomposition while minimising the release of odorous gases.
Every household should also play their part in proper segregation. Active participation by every resident at the household level will have a profound effect on waste management systems. However, despite the continuous effort made by conservancy workers and GCC, segregation poses a major challenge in Chennai. Our behavioural and cultural habits means that we often think of our own waste as something that needs to be addressed by external agencies. We need consistent efforts to change these long-standing attitudes towards waste management.
Apart from taking active steps to address concerns of odour around the sites, raising community awareness about the composting process and its environmental benefits can be highly beneficial. This includes engaging households to see the waste management process as an extension of their own responsibilities. This could take the form of organising visits to nearby composting centres, which can offer a hands-on understanding of the process and inspire residents to actively participate in sustainable waste management practices.
The solution? A simple fix!
The primary reasons cited for the closure of GCC’s processing centres are not particularly serious but rather stem from relatively minor and easily addressable issues. These can be effectively resolved by adhering to proper operating procedures and looking through some better processing centre examples. This does not necessitate looking at global examples, as GCC can explore solutions from other Micro Composting Centers (MCCs) successfully operated by NGOs and private entities in partnership with GCC.
Picture 3 - Ward 63 composting center in Pudupet, Chennai ICAG
Ward 63 is a case in point. The doors of Ward 63's Micro Composting Center open to reveal neatly organised compost piles and well-maintained pulveriser and sieving machinery. Unlike many other centres, this facility greets visitors without the unpleasant odour of rotten eggs or the infestation of maggots. The center was spotless, and it is maintained by Namma Ooru Foundation. Furthermore, similar centres can be found across the city which are run by other NGOs or partnerships, all adhering to a straightforward actionable plan and its successful execution.
The answer to our waste management problems is not in burning waste but in treating it as the resource that it is.
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