A tale of two dump yards

From street corners and vacant lands to rivers and ponds, Chennai is drowning in the garbage that its millions of residents are generating every day. Disposing the urban waste, a challenge for cities across the world, is an issue that the Greater Chennai Corporation has been grappling with for years. However, despite several plans and proposals put forth over the years, the municipal authorities are yet to find a solution to the 5,000 tonnes of garbage generated daily.

The effect of this is evident on the Pallikaranai marshland, a crucial ecosystem that not only aids flood mitigation and groundwater recharge, but is also a high bio-diverse area that serves as wintering and staging grounds for several migratory birds.

In spite of this significance of the only urban wetland of Chennai, the rampant urbanisation has reduced it from the original expanse of 5,500 hectares in 1965 to about 600 hectares in just five decades. What made it worse was the Chennai Corporation creating two dump yards spread across 70 hectares. Following severe and persistent criticism from experts and environmental activists, dumping of waste has been suspended for now.

After the Union Environment Ministry notified solid waste management (SWM) Rules in 2016, the Municipal Administration department had come out with a policy to ensure zero-waste by following the concept of reduce, reuse, recycle and recover.

The GCC is also exploring different processes to dispose of the waste, the most recent being the process to convert organic waste into manure by setting up waste processing plants in every ward in the city. It has also been planning to set up two waste-to-energy (WTE) plants – the latest is a proposal to set up two plants with a capacity of 26MW and 32MW at a cost of Rs 1,442 crore.

The State and city have indeed made some progress, but the lack of a comprehensive plan has led to the situation where the end result remains abysmal.

For instance, Tamil Nadu has achieved 96 per cent efficiency in collection of municipal solid waste and 67 per cent efficiency in door-to-door collection as per a 2018 report. However, the report adds, almost 90 per cent of the waste is not treated and 98 percent of municipal solid waste continues to be deposited in open dumps. The policy states that a maximum of 20 per cent waste should be send to the landfill for safe disposal, but the garbage mounts at Kodungaiyur and Perungudi yards that are getting bigger by the day is a clear evidence of the below par execution of the policy. According to R Govindaraj, president, Exnora Greater Chennai, the city Corporation has managed to collect only 4,000 tonnes of waste. That means there is a daily backlog of 1,000 tonnes of waste on the streets of Chennai – or 3.65 lakh tonnes per annum – a number that is growing each passing year. “The way the collected garbage is disposed of leaves a lot to be desired, as there exists no comprehensive mechanism except dumping them invacant lands,” rued Govindaraj, whose organisation has been involved in creating awarenesson managing household waste in a decentralised manner.

While searching for a model it can emulate, perhaps the city should look to Singapore which adopted a garbage disposal plan in the seventies. Being a tiny City-State where space comes at a hefty premium, the island nation has been at a disadvantage when it comes to dealing with tonnes of waste. That is how it arrived at the idea of incinerating it.

Based on the blueprint for sustainable Singapore, the first waste-to-energy plant became operational in 1979. Today, all incinerable waste is disposed of at four waste-to-energy plants, that generate energy to meet up to three per cent of Singapore’s requirement. Another plant that is expected to go on stream in 2019 is set to generate 800 kilowatt hour of electricity per tonne of waste. This is a great leap from Singapore’s first incineration plant, which produced 180 kilowatt hour per tonne, the report said.

A key part of this plan is the effective disposal of incineration ash. Owing to lack of suitable landfill sites on the space-starved mainland, the government there developed a landfill about eight km south of Singapore in 1994.

Experts from the country’s National Environment Agency designed the 350-hectare landfill with an array of features. After combining two islets to form the landfill, a seven-km perimeter rock bund was built around it. It is lined with an impermeable membrane and a layer of marine clay so that the toxic chemicals that leach from the ash does not enter the sea or permeate into the land. The landfill, Pulau Semakau, is divided into 11 bays (called cells) where the ash is dumped till ground level. After that, it is covered with soil, and grass and saplings are planted. Over the years, corals and mangroves from the site were relocated or replanted. These serve as an indicator if there is any leaching. There is also an onsite treatment plant to process the water from the landfill. In 2005, Pulau Semakau was opened to the public for sport fishing, birdwatching and other recreational activities. It is expected to provide for Singapore’s waste disposal needs till 2035.

In the beginning of the year, the ban on single-use plastic came into force in TN. In contrast, Singapore has not brought in such a ban because there is no segregation of garbage there. All garbage collected is being sent for incineration and the waste is collected in the form of pellets. There indeed are experts who question the move to incinerate all the waste, as it has its own risks and challenges. Singapore model is one that Chennai can look at to deal with the menace.