CHENNAI: Centralised waste management and end-use of the biogas as bottled bio-CNG (compressed natural gas) are two aspects of concern in the city Corporation’s proposal to set up a 50 tpd (tons per day) at a centralised location, according to Citizen consumer and civic Action Group (CAG).
The project proposes to manage biodegradable waste from the hotels association at the biogas plant and purify the biogas to bio-CNG and selling it back to the hotels.
However, the CAG, in its evaluation said that centralised waste management plants have not demonstrated the ‘claimed utility’ even once in India. Taking Bangalore and Pune as cases in point, both these plants ran into a loss and had to shut down. Besides, after spending large amounts of resources, both spots only went on to become a ‘sore spot’ for residents staying near these plants, the report said.
The issues with centralisation lie in the high costs incurred in collection and transportation of waste since these plants are usually set up in the outskirts. This may take up 40-50% of the total cost of operations. Attempts to reduce the cost of operations may lead to generation of smell and leachate, the report said.
As for biogas bottling as the end-use, the process would require high capital expenditure.
“While the bottling equipment itself is very expensive, the need for 4 or more days’ worth of biogas storage capacity, further increases the capex,” the evaluation said.
“The need for higher storage is due to the fact that the customers using the cylinders may return the cylinders only in 15-20 days, while the biogas is still continuously produced at the plant site. Thus, a need for having a higher storage capacity is needed,” it added.
The process would also warrant high electricity requirement for these processes.
As an alternative to this proposal, the group suggests a decentralised biogas plant which may help in reducing waste transportation cost and offers the possibility of direct biogas supply to private customers, at a comparatively lower cost.
Tricycle routes optimised for conservancy workers in ward 100 of the city Corporation:
Conservancy workers in ward 100 are now tricycling shorter distances after optimisation of their routes.
The Citizen consumer and civic Action Group (CAG) began a pilot for Zero Waste Chennai in ward 100 of the city Corporation (Anna Nagar), in May this year.
To reduce the distances, the city Corporation has set up both Materials recovery facilities (MRF) and a Micro Composting Centres at the Arumbakkam burial ground and at sixth avenue. The ward 100 office has an MRF in place.
“Once the bins on the tricycles are full, the waste is transferred to the battery-operated vehicles, that are doing the rounds in the area,” said Satyarupa Shekhar, Director (Urban Governance), CAG.
Going forward, there would be designated transfer points where the sanitary workers can drop off waste once the bins are full, she added.
Speaking to Express, a Corporation official said, “Earlier when the bins were full, they had to go to the Arumbakkam burial ground to dump the waste. Now, it is picked up by battery-operated vehicles.”
The sanitary workers cover around 250 households each.