“Namma ooru, semma joru…” – the catchy song playing from garbage collection vehicles every morning is a familiar sound for most Chennai residents. The Greater Chennai Corporation (GCC) anthem is a reminder to take out the garbage, as the conservancy workers do their rounds in battery-operated vehicles (BOVs) collecting waste door-to-door. 

Some residents diligently segregate the waste into dry, organic and reject categories before handing it over to conservancy workers. Others just get rid of the mixed waste without a thought about where it will go and what would be its environmental impact. And the cycle repeats every morning.

Ever wondered about the life cycle of trash and where it all ends up? What quantity of the waste is recycled and how much of it makes the journey to the landfills, which are already overstretched? 

We give you a lowdown on the journey of waste — from your door to the dumping grounds.   

But first some background…       

As Chennai is expanding in area and population, one of the world’s oldest city corporations faces challenges in waste management. Based on the 2011 census, the city’s population was 4.6 million and is currently estimated to be about 7.1 million, according to the GCC. As the population grows, the demand for essential resources and their consumption is rising exponentially. If consumption of resources goes up, can the increase in waste generation be far behind? 

The city generates around 6,100 metric tonnes (MT) of solid waste every day, with 800-900 MT being construction waste. Approximately, half of this construction debris is processed at dedicated facilities. Recently, the GCC has also designated specific locations for the disposal of construction waste. 

Read more: What happens to your dry waste in Chennai?

Here are the various steps and processes employed by GCC for the management of solid waste in the city.  

How is household waste collected?

The conservancy workers use BOVs for door-to-door collection of garbage across households. About 95% of the household waste is collected in this way in all the 15 zones in the city and the use of tricycles has almost been phased out. Currently, 5,966 BOVs are in use, reducing the presence of roadside garbage bins to some extent. The garbage collected by conservancy workers is then sent to the segregation and processing facilities.

Dilip Srinivasan, a resident of Thiru-vi-ka-Nagar (Zone-6) says, “Among 100 people, only 2 to 4 segregate their waste and hand it over to sanitary workers. The remaining 96 blame the GCC, saying the waste would be mixed anyway and end up in the landfills. From the sanitary workers’ perspective, if they refuse to collect unsegregated waste, people simply dump it on the roadside. So, the overburdened sanitary workers still collect this waste, which makes their job difficult.” 

Residents rarely take responsibility for the waste they produce. “The corporation has not taken steps to create awareness about source segregation nor made the practice mandatory. The responsibility falls on the sanitary workers, who are exposed to a toxic environment. This issue should also be viewed through the lens of social justice, as many sanitary workers are from the Dalit community,” Dilip adds.

Zone-wise waste collection data

How is trash collected from Chennai roads?

The GCC has introduced mechanical sweepers in many zones, yet conservancy workers do much of the cleaning. In the daytime, their schedule is from 6.30 am to 1.30 pm, while the night conservancy happens from 9 pm to 2 am. The sanitary workers use brooms, baskets, brushes, iron plates, containerised push carts, tricycles with bins and roto-mould wheeled bins. After sweeping, the waste is collected and stored in the specified bins. These bins are then sent to the disposal site. 

Sumathi*, a resident of Vyasarpadi (Zone-4) says, “For the whole city most of the sanitary workers will be from North Chennai, but our streets won’t be as clean as Central and South Chennai. Does it sound contradictory? That’s because the GCC focuses on deploying more sanitary workers, machines and equipment in Central and South Chennai though the population in North Chennai is more in comparison. Even the waste collected in the central part of the city comes to Kodungaiyur dump yard, so the trucks carrying waste litter our roads, as they do not have closed containers.”

Equipment used for the collection of waste

How does waste segregation happen?

Transfer stations receive all the waste collected from across the city. There, workers separate the waste and transfer it in trucks to respective processing facilities: 

• Wet waste goes to Micro Composting Centres (MCC) at the ward level, and Bio-gas and Bio CNG plants. 
• Recyclable dry waste is sent to Material Recovery Facilities (MRF), Resource Recovery Centres (RRC) and Plastic Baling Centres.
• Incinerators burn non-recyclable waste.  
• Garden waste and tender coconut waste are sent to designated processing facilities. 
• Inert waste is sent to landfills.

What happens to the dry waste?

The different types of dry waste are further separated at the MRFs and RRCs. Certain plastic materials that can be recycled to generate revenue for the corporation are segregated at the recovery centres. Plastic baling centres convert these materials into fuel for cement factories.  

“We burn non-recyclable waste from all 15 zones such as mattresses, dresses, bags, footwear, plywood, leather, and thermocol here,” said staff at the incinerator facility in Kodungaiyur. The capacity of the incinerator is 50 MT. After burning this waste, workers filter the remaining ash and mix it with cement to make hollow blocks. “It is now being tested for use as manure for agriculture,” he added.

But are the GCC’s efforts enough for sustainable waste management? “Chennai has a processing capacity of 2,460 MT/day, but these facilities process only 637 MT daily. The capacity utilisation is a dismal 26%. Also, to dispose of non-recyclable plastic waste, the GCC has two incinerators to burn 60 MT of plastic per day. But these plants have pathetic pollution control systems and cause many health issues for nearby residents,” says DK Chythenyen from the Centre of Financial Accountability.

Construction debris and garden waste

The GCC outsources the collection and transportation of construction and demolition debris in seven out of 15 Zones and the processing centres at Kodungaiyur and Perungudi process about 495 MT of C&D waste. In the remaining eight zones, GCC collects and transports construction debris to the dump sites.

The debris, consisting of stones, rocks and various sizes of wood, iron, and other materials, is initially placed on a conveyor belt where other waste is manually removed and sorted with the help of a magnet. The remaining debris is then sent to crushers, which reduce the large pieces into smaller rocks, gravel, sand, or rock dust.

“These processed materials, of different sizes, are only suitable for landfilling and not recommended for construction,” explained a person in charge of a GCC construction debris processing site. Despite the facility’s capacity of 100 TPH (tonnes per hour), the average processing rate is 70-80 TPH.

Meanwhile, some of the waste from parks and gardens is processed to make briquette, a compressed block used as an alternative to coal or wood. These briquettes are being sold to companies with furnaces and boilers.

At a tender coconut processing facility, workers process the shorter fibre as a base for plants. The longer fibre is used to fill mattresses.

The final destination: dumping grounds

The Perungudi dumpsite has received nearly 700,000 MT of waste to date, while the Kodungaiyur dump yard has received 6,652,505.67 MT. This accumulation makes the surrounding environment and residents more vulnerable, exposing them to health risks.

Despite processing and recycling efforts, a daily average of nearly 2,600 MT is deposited in the Kodungaiyur dump yard and 2,400 MT at the Perungudi site. This means only about 1,100 MT of waste is processed, leaving the majority to end up in these dumpsites.

[*name changed to protect identity]

Also read:

• How can Micro Composting Centres in Chennai be improved?
• Why a waste-to-energy plant is not the answer to Chennai’s garbage problems