What ails Bengaluru’s waste processing plants?

Waste piles in Karnataka Compost Development Corporation (KCDC) plant in the Bommanahalli constituency caught fire, while citizens in the area watched in bewilderment. This is only one of the many examples of how waste processing is mismanaged in Bengaluru, even as the new government is trying to look at the root causes and fix the problem.

Managing municipal garbage is a perpetual challenge that keeps both governments and citizens on their toes. A few years ago, the scope of solid waste management in Bengaluru was to collect and transport for landfilling in a remote place out of the city. However, the unscientific management of Mandur and Mavallipura landfills impacted the environment and the people living around them.

This was duly recognised by the judiciary that passed strict orders for scientific solid waste management, from where starts the story of solid waste management processing plants (centres) designed specifically to handle wet (biodegradable/compostable) waste.

Also Read | Whitetopping of roads, legacy waste disposal get lion's share in Budget for Bengaluru

Municipal solid waste processing plants in Bengaluru were a reaction to villages on the outskirts of the city protesting against landfills. When the High Court gave a deadline of six months to find a solution to the plaguing crisis, the same landfills were converted to processing facilities for Rs 440 crores.

Today, Bengaluru has seven wet waste processing plants established with a total capacity of 1,620 tonnes per day. Out of them, five are running, while two of them are not, due to local pressure. Officials say the five plants running are receiving about 900 tonnes of waste per day — 55.5 per cent of total capacity.

This does not mean there is not enough wet waste in the city. Bruhat Bengaluru Mahanagara Palike (BBMP) officials claim that there is 50 per cent segregation in the city. This means that out of roughly 4,200 tonnes of household waste per day produced in the BBMP limits, about 2,500 tonnes are segregated to give 1,250 tonnes of wet waste, which is sent to the processing plants.

Also Read | KSPCB flags lapses as trash chokes Gokarna

Officials say that the segregation levels can be increased if the plants run at their full capacities. However, protests by local villagers due to the stench and leachate emitted by plants are the major hindrance to the plants running at total capacity, which again circles back to the unscientific management of the plants.

Meanwhile, officials say that a plant being run by MSGP Infratech Pvt Ltd in Doddaballapur is receiving 500 tonnes of waste. But nobody knows what happens to the wet waste there, and the plant has been closed many a time due to local protests, only to reopen later.

However, the underutilisation of plants has not stopped the mismanagement of the plants. The challenges for these plants are many: environmental, social, technical, financial and political.

Environmental challenge

Firstly, these processing plants are supposed to be in areas which are away from human habitations, water bodies and eco-sensitive zones. They are a red-category industry and should be placed in areas meant for such industries.

But the locations of present plants are now practically within the city limits, with the city expanding and engulfing the villages on the outskirts. These plants are supposed to be planned and built for the said capacity with leachate treatment plants and odour control mechanisms. They need environmental clearance and authorisation from Karnataka State Pollution Control Board (KSPCB) before establishment. These plants need regular maintenance and continuous monitoring for odour and pollution by qualified technical skilled personnel.

However, many of these conditions are not being strictly followed, leaving an opportunity for anyone opposing the plants to move to court. Thus some of these plants are embroiled in court cases.

The people living around the plants protest when they face an unhygienic environment. No one wants a smelly, flies-ridden neighbourhood that makes breathing impossible. Take the case of the Karnataka Composting Development Corporation plant in HSR Layout. The MLA promised to close it down before the elections, and it did for some weeks. However, the order was not official and the plant is working again.

The sufferings of locals have led to protests, where people do not allow garbage vehicles to carry the waste to the processing centres. This also leads to many processing plants not getting enough wet waste.

Technical challenges

Solid waste processing plants work on the principle of composting organic material through windrow composting methodology. In this method, organic waste is kept in rows of long piles called “windrows”, which are turned periodically either manually or mechanically to aerate them.

The degraded material thus produced is segregated through the trommel method of sieving, to separate the compost and non-biodegradable waste that might have crept into the waste stream.

The residual non-biodegradable after the compost has been segregated is called refuse-derived fuel (RDF). In Bengaluru, the compost is further graded and sold whereas the RDF is sent to cement kilns as fuel for incinerators.

In an ideal situation, this method requires large tracts of land, sturdy equipment, a continual supply of labour to maintain and operate the facility, and patience to experiment with various materials mixtures and turning frequencies. This method needs good technical know-how and expertise in microbiology.

The technical capacity of the processing plant versus actual power varies in terms of the sieve trommel, its capacity to process, composting enzyme composition, and the area needed for windrow composting which technically demands a certain height and breadth of the windrow pile for less odour and less leachate.

The co-relation and the mathematical specifications have to be worked out as per the processing capacity including trommel sieve requirement, windrow composting area requirement as per standards, composting enzyme specifications, etc. If one of the critical components/processes does not work, the entire plant fails and an unbearable stench becomes inevitable. Hence running a processing plant through windrow composting methodology is risky and the chances of failure are high in terms of odour and leachate management.

Tipping fee vs processing fee

Right now, the BBMP is managing some of the waste processing plants, while some are managed by private operators that look after the operations and maintenance. These operators were being paid a tipping fee —which is pre-processing and a kind of dumping fee which discourages the processing of waste, as the payment is made for just receiving the waste.

This is the same model that failed Bengaluru’s solid waste management scenario, pushing the Mavallipura and Mandur areas to disaster. The operators were incentivised to receive waste and not process it. Going with this model will result in the same type of output where operators pile up the waste and do not process it.

When a robust, efficient, transparent processing fee methodology linked to the output was implemented in a few plants, there seemed to be some improvement. However, this was withdrawn for reasons best known to BBMP.

The processing fee model demands actual processing of the waste and the fee was paid based on the compost recovered as per the grades and the refuse-derived fuel (RDF) recovered. This is a model that will improve the output and save the public money spent on waste management.

The political face of the problem

The political will to address the solid waste management issue including the collection of source-segregated waste, transportation, aggregation and processing is the need of the hour. All these need to work seamlessly with the capacity for all being optimal and without gaps. Any gaps in collection or transportation or processing can lead to failure again.

The total approximate wet waste produced in Bengaluru city is 2,800-3,000 tonnes per day. Therefore the city will need more integrated wet waste processing plants with dynamic robust technologies including biogas as waste-to-energy and the slurry conversion to high-value compost. Utilising governmental schemes like Sustainable Alternative Towards Affordable Transportation (SATAT) for funding and aligning with the climate change and carbon reduction programmes, the city can garner a much-needed reputation as Brand Bengaluru for being eco-friendly in a sustainable city.

The importance of processing waste has been given very high importance in the Swaccha Survekshan 2023, as the separate valuation of the processing of waste in the city has been implemented. A lot is at stake to keep our city’s brand for being clean and green by adopting climate-resilient technologies in solid waste management and thus reducing greenhouse gases.

In conclusion, technically sound, processing fee-based waste processing plants established in red-category industrial zones with environmental clearance and KSPCB authorisation, climate-resilient, eco-friendly, people-friendly, wet waste processing plants are a need of the hour. This cannot be ignored any more.

Political will and people’s cooperation — both are needed to make better solid waste management for Brand Bengaluru to be a reality. This can also help Bengaluru achieve a higher rank in Swachha Survekshan.

Managing the stench and leachate

Proper windrow management will eliminate the stench to a large extent, says a BBMP official. Each plant has 9-10 acres of land, and he says it is capable of containing the smell and the aftereffects inside the buffer zone.

BBMP officials say all the waste processing plants have concrete storage areas, where the leachate is collected and then transported to private treatment facilities in Malur and Kumbalagodu. Some of it is also sent to BBMP’s own leachate treatment plant in Chikkanagamangala plant premises which can process 50,000 litres per day.

Yet another leachate treatment plant is on trial in Doddabidarakallu plant premises managed by the BBMP. This plant was functional earlier but stopped due to technical and upgradation issues.

Officials say the Indian Institute of Horticulture Research (IIHR) has conducted a study for two years and has submitted a report on the feasibility of using leachate in agriculture and horticulture. Based on this, BBMP hopes to get KSPCB’s approval to use leachate in farming as a liquid fertiliser.

(The author is a solid waste management expert advising the BBMP on Swachh Survekshan)

(With inputs from DHNS)