Anatomy of a landfill remediation in progress  

It is noon. Armed with a thick mask and trepid anticipation of a strong stench I am on my way to the Perungudi dumping ground, a landfill site in Chennai where some packages of legacy waste remediation are soon to be completed. 

But at the site, I am in for a big surprise. As I weave my way through the road carved out along the waste, there are no scavengers circling the sky, no rats scurrying around and, believe it or not, no stench to speak of. As one reaches the operations office at the centre of the site, I remove my mask as if I were in an office anywhere in the city.  

A Blue Planet project in Perungudi, Chennai.

Biomining process

My appointment is with a representative of Zigma Global Environ Solutions Pvt Ltd., part of Blue Planet Environmental Solutions Pvt. Ltd., the group which is executing the project. She shows me the biomining process the company follows every time it transforms a gigantic landfill into land to be usefully repurposed.  

At Perungudi, post remediation, the Greater Chennai Corporation’s action plan is to set up a bio CNG plant, an automated material recovery facility, a windrow compost plant, phase-II of biomining, and above all, an eco-park, replete with a Miyawaki style forest. The idea is to treat fresh waste as it comes in and not let it pile up as legacy waste has for the past 30-40 years. 

A Blue Planet project in Perungudi, Chennai.

Legacy waste comprises a range of solid waste kept for years on barren land dedicated as a landfill. It includes construction and demolition material, waste stored in tanks, canisters, bins, buried waste, contaminated soil and structural waste.  

The odour-free atmosphere at the landfill is thanks to the bio-mining process followed. “Our waste management is founded on a pragmatic and sustainable approach to addressing both legacy waste at landfills and fresh waste, explains Prashant Singh, Co-founder and CEO of Blue Planet. He explains the stages they follow for biomining. It begins with pre-stabilisation of waste by using excavators and an aerobic process called windrow to keep turning the waste. Bioculture and deodorizer are then sprayed to accelerate the degradation process and control odour. This speeds composting and leachate collection pits ensure complete waste treatment. Result: good enough soil to pass the germination test and for afforestation.  

A Blue Planet project in Perungudi, Chennai.

Of the waste that remains the segregated combustible fraction undergoes RDF (refuse derived fuel) processing and is sent to cement plants to use as alternative fuel. Coarse soil and stones are best for reclamation of low-lying areas. 

Bio-mining is a complex process, and Blue Planet has completed over 25 projects in seven states, giving back 600 acres of land to the municipalities. It processes 20,000 tonnes of legacy waste a day and has developed its segregation process indigenously. It is now going to export its machines. “The first machine that we installed processed four tons a day in 2017-2018 and today the same machine processes 1,000 tonnes a day,” says Singh as he outlines their real-time monitoring system which can give details of the crore ton of waste the company has collected in the last five years. “This kind of tracking and traceability and transparency never existed in our waste management sector before.” 

Tackling legacy waste

Perungudi is an example of the country’s effort to tackle legacy waste which was mandated in the Swachh Bharat Mission 2.0 wherein urban local bodies were directed to complete remediation of their existing dumpsites by 2023 for cities with less than 10 lakh population and by 2024 for larger cities. But this had to be done scientifically with compliance to environmentally sustainable methods. 

According to the Centre for Science and Environment, India has over 3,000 dumpsites holding over 1,300 million tonnes of legacy waste and occupying over 10,000 hectares of urban land.  

However, tackling legacy waste is one aspect, but managing fresh waste daily to avoid a build-up is as, if not more, crucial. Blue Planet is working on a project in Kerala where it will process almost 90 per cent of the fresh waste collected. The remaining 10 per cent will go to sanitary landfills that it will manage. “Fresh waste processing aligned with legacy waste remediation is essential,” says Singh. And the key to a circular waste economy.