Mountains of muck, those stinky black spots of mixed garbage, are rising across the city again. But even as the Bruhat Bengaluru Mahanagara Palike (BBMP) claims to tackle them with a steep 36% garbage tax, a workable way out remains largely ignored: Wet waste composting. Localised ward-level composting with a multi-stakeholder approach could potentially solve half the problem, and the time is now.
Bengaluru generates an estimated 6,000 Metric Tonnes (MT) of solid waste every day, and almost 2,800 MT is wet waste. The lack of a city-wide, well-structured composting mechanism has meant that a big chunk of the wet waste gets mixed up and eventually ends up in landfills. Can the success stories from many apartment complexes and a recent public-private project involving the Bengaluru Metro Rail Corporation Limited (BMRCL) be replicated and scaled up?
Dubbed as the Solid Waste Management (SWM) user fee, the BBMP’s garbage tax is bound to generate an additional annual revenue of ₹750 crore. The bulk of this money will go for the collection, transport, processing and disposal of waste. But SWM experts ask why the same money can’t instead be used to buy compost bins for all the three million households in the city and tackle the mega problem at source? Part of it, they say, could also build a robust network of ward-level composting centres.
Ideally, hyper local composting with active involvement and monitoring by ward committees should have had a working system by now. But this has been a non-starter without an elected BBMP Council and corporators. The best bet now could be emulating the composting success models, now up and running in many apartments. Big complexes that generate more than 150kgs of wet waste daily are composting through internal converters and using it as manure for gardens.
The soil-less compost garden set up by BMRCL in the median space between Metro pillars along a pilot stretch in the city.
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Compost-based gardens
Big government corporations could show the way too. The Bengaluru Metro Rail Corporation Limited (BMRCL) has launched one such initiative by introducing soil-less, compost-based gardens in the median space between the Namma Metro pillars. The project, a public-private initiative, involves Pelican Kenterra and Wipro Foundation. Instead of soil mined from fertile farmlands and mountains, the method utilises reject compost and garden waste from commercial establishments and residential communities.
Under the PPP project, a trial stretch of 100 metres has been installed by Kenterra near the Manjunath Nagar Metro Station. The medians between five Metro pillars were filled with over 20 MT of compost converted to soil-less gardening material. To fill the trial stretch, about 600 cubic metres of natural compost and garden waste were sourced from the Wipro forest area in Sarjapur. The median space was then planted with ornamental plants. An additional five km of Metro medians will now get the same compost gardening treatment between HSR Layout and Bellandur.
The technology to convert biodegradable waste into soil-less planting material had won the Swachh Technology Challenge. Here’s an explanation by the start-up: “All biodegradable matter, even the toughest of it, coconut shell, will eventually degrade to create a soil-less planting media into which plants can be simply inserted. No soil is required. The technology involves using microbial inoculums for degrading the lingo-cellulolytic matrix of plants and the protein, fat, and carbohydrate matrix of the animal residue into a medium with low electrical conductivity. Plants will grow as in soil in this medium.”
These out-of-the-box solutions need to be scaled up to make a bigger impact. But at the ward-level, barring a few bio-methanisation plants and lane composters such as in HSR Layout, decentralised composting is insignificant compared to the huge amount of waste generated, says Dr. Shanthi Tummala, a founding member of the HSR Citizen’s Forum and a member of the Solid Waste Management Round Table (SWMRT).
Trees being replenished with excess compost prepared by apartment residents in Domlur.
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Pilot projects need scaling up
A good number of apartments have a composting system in place, some activated by eco-conscious residents and some following the mandated rule for bulk generators. The lane composting initiative in HSR Layout, funded by CSR initiatives, has been successful. “The whole lane wastes are being processed by those composters. But all these are pilot projects, which the government should scale up,” she says.
Glimpses from HSR layout SwachaGraha Kalika Kendra, a learning centre for Solid Waste Management.
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There is no dearth of funds, says Dr. Shanthi, while seeking more transparency from the government in how the additional revenue through the SWM user fee will be utilized. “We really appreciate this fee because every citizen should be responsible for the waste they generate. But after paying the user fee, what change will the citizens see?” she wonders.
Glimpses from HSR layout SwachaGraha Kalika Kendra, a learning centre for Solid Waste Management.
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Need for transparency
Paying citizens demand transparency and accountability, and wonder whether the BBMP will set up a monitoring system to track segregation at source and whether the collection is regular. “Besides, what will be the incentive for people who are consciously composting? How is the exemption planned? Is there a plan? Unfortunately, there is no strategy shown, nothing is being discussed with the citizens. They don’t invite eco-conscious citizens to share their ideas. They can’t make decisions inside four walls. People on the ground should be involved.”
SWMRT wants the government to utilize part of the SWM user fee to set up a bio-methanisation plant at least at the constituency level. As she elaborates, “The additional funds should be used to ensure a dry waste collection centre in each of the 243 wards with proper infrastructure and ensure that it functions. If these are set up on a war-footing, the majority of the waste going to the landfills will be cut down.”
At the forefront of the composting campaign in the city, environment changemaker and founder, Beautiful Bharat, Odette Katrak has ensured that no wet waste gets out of her 37-flat apartment complex in Domlur. The 15-20 kgs of wet waste generated is composted within the complex for the apartment garden, and the excess compost is used to enrich the avenue trees and soil in the layout.
Odette, who conducts monthly cleanup drives, draws attention to a related problem: “Many people put extra cooked food into the compost system because they don’t want to keep it till the next day. Why compost good food, when you can give it to someone else?” she asks.
The worst case, says Odette, is food waste dumped in plastic covers on the roadside. “We see it every day in every part of the city. That rotting waste in plastic will generate methane and they are all collected in tractors and dumped in landfills. It is a very huge contributor to climate change.”
Dangerous leaf-burning
Leaf composting is a proven eco-sensitive way to replenish trees. But Odette cites leaf-burning as an issue that needs serious attention. “In Domlur, we used to have a leaf composter unit set up through a corporate CSR initiative. When it stopped, there was heavy burning of dry leaves. The pourakarmikas would sweep and put the leaf pile in a corner. Someone comes and lights it up, leading to air pollution and emanating carbon monoxide due to incomplete combustion. These are very harmful, and can cause lung cancer and other problems. Heart patients and asthma patients are at higher risk.”
Under its green initiative, the BBMP is now in the process of setting up 100 leaf compost units in many of the 1,280 parks under its jurisdiction. On-site composting of the fallen dry leaves would be used for plant and tree maintenance within the parks.
Published – April 10, 2025 09:00 am IST
