Why is Bengaluru expanding its waste-management capacity? | Explained

The Government of Karnataka is contemplating the relocation of waste processing facilities, operational in Bengaluru, to the outskirts of the city. Officials have been tasked with identifying land parcels, each spanning 100 acres, in various directions from the city, preferably in Bengaluru Rural and Ramanagara districts.

Currently, the city generates approximately 5,000 tonnes per day (TPD) of waste, which is expected to rise to around 6,000 TPD over the next four or five years. The existing waste processing capacity in Bengaluru stands at about 2,000 TPD, including small-scale decentralised ward-level waste processing facilities, leaving roughly 3,000 TPD of waste to be disposed of in landfill quarries without processing.

Why is opposition expected?

Due to this capacity shortfall, Bengaluru has made a commendable decision to identify locations for four additional waste-processing facilities outside the city. However, this initiative will face significant challenges, primarily from the villages surrounding the locations.

Historically, composting facilities at most waste-processing sites set up by the Bruhat Bengaluru Mahanagara Palike (BBMP), such as at Kudlu, Mavallipura, Mandur, Lingadeeranahalli, Kannahalli, and Seegehalli, have encountered strong opposition rooted largely in the inefficient operations at these plants. The plants have indeed consistently received more waste than their designed capacities and have operated at less than 50% efficiency.

This excess quantity of material in the process has resulted in leachate and odour issues, affecting the environs and livelihoods of people living nearby.

What should be the plants’ operational protocols?

Given the issues posed by existing plants, it is crucial to make sure that the city’s waste processing capacity is increased to handle 6,000 TPD, through a combination of centralised and decentralised processing systems. This expansion should ensure that no facility receives more waste than its designed capacity. By increasing the capacity and ensuring that waste deliveries are never more than the design capacity, it should be possible to mitigate leachate and odour issues effectively.

The new waste-processing facilities should ideally have the capacity to process 1,000 TPD to ensure that all the 6,000 TPD of waste generated in the city are processed.

The technology of choice should be composting of fresh waste, which is also suitable to the weather conditions of Bengaluru. About 60% of the waste here is biodegradable wet waste, some 25% is dry waste (including plastics and other recyclable materials), and the remaining 15% consists of inert materials, such as silt and stones.

Each facility should be designed to incorporate a 600-TPD composting facility, a 250-TPD material recovery facility (to manage dry waste), and a 150-TPD scientific landfill to dispose of the inert fraction.

How can the State address local concerns?

Addressing odour and leachate concerns is paramount. These plants should have tertiary-level facilities to treat leachate and ensure they are properly treated, making them suitable for internal use.

The main cause of odour in waste-processing facilities is the high moisture content in the material when it is being composted. To manage this, the waste-processing plants should be equipped with high-capacity lane turners or windrow-turning equipment instead of having to be turned manually using excavators. Turning the composting material around at frequent intervals can expedite the composting process and minimise odour because the material will be well aerated and regulated.

Another major concern is likely to be land acquisition and changes in land-use patterns. Considering the new plants will have to be set up quickly, the government may opt for state-owned vacant plots, as it has in the past, to avoid the tedious process of land acquisition. However, change in the use of land from an open space to waste-processing will affect the local terrain and rainwater management. To address these issues, the government must conduct thorough geotechnical investigations first.

Considering these plants will be located in rural areas, the government should also engage the primary consumers of the compost – i.e. farmers – in the process in addition to offering free organic compost to villages settled near these facilities. This initiative can substantially reduce the farmers’ reliance on chemical fertilisers, saving them around 15,000-20,000 rupees per annum (which they currently spend to buy fertilisers).

In fact, the annual waste output of Bengaluru, around 2.16 crore tonnes, could yield approximately 32.4 lakh tonnes of organic compost, ultimately replacing a significant portion (possibly up to 50%) of chemical fertilisers used in the Bangalore Rural and Ramanagara districts.

Can existing facilities be repurposed?

Existing facilities have been a source of concern for residents and have faced demands for closure due to odour and leachate issues. Given the significant government investment of Rs 450 crore to set up seven composting facilities of 150-300 TPD capacity each in 2014, a more practical approach will be to convert these wet-waste-processing facilities into dry-waste management facilities.

These converted plants can handle about 150 TPD each of the dry waste generated in the city, thus reducing the transportation cost for the BBMP by 20%. This approach could also ensure that the proposed new plants can operate at 80-85% capacity, which is a more feasible utilisation rate.

Moreover, dry-waste segregation facilities are less likely to pose problems to residents, as they don’t produce leachate or odour. They can also create job opportunities for at least 50 people for sorting, baling, bagging, and other related activities in each facility.

Why does the city’s waste-processing capacity need a boost?

Setting up new waste processing facilities will attract opposition and cost the government more to transport waste to distant sites. However, it is necessary to increase the waste-processing capacity of Bengaluru in order to comply with municipal solid waste management rules and the National Green Tribunal’s guidelines, and as an environmental obligation towards the State.

The success of the proposed facilities and the sustainable use of existing facilities (within the city) depends on strategies that consider technology, environmental impact, social impact, past experiences, and community involvement. Not considering these factors will inevitably lead to the waste-processing sites becoming landfills. By focusing on these factors, Karnataka can pave the way for a more sustainable and efficient waste-management system.

The present situation of unprocessed waste disposal in the city and rampant use of chemical fertilisers in rural areas can also be ameliorated by setting up and operating scientific waste-processing, which will benefit both city dwellers and rural residents.

Pushkara S.V. is a practitioner at the Indian Institute for Human Settlements. He has provided advisory services on solid waste management to 75 urban local bodies on waste management and has headed operations at a 750-tonne-capacity waste processing facility.