Written by: Bharath Vetriivel, AVRIS Environment Technologies
The Greater Chennai Corporation, in association with AVRIS Environment Technologies, has installed a food waste treatment plant called ‘CHUGG-75’ at a government canteen or Amma Unavagam in Adyar, southern Chennai, serving 300 people per day. The plant was inaugurated in February 2021 by Dr. Alby John Varghese, IAS, former Regional Deputy Commissioner, South, Greater Chennai Corporation.
CHUGG-75 is a biological treatment system which enables in situ treatment of food waste. It has the capacity to treat 75 kg of raw food waste per day and occupies a minimal foot space of 28 sqft. Compared to traditional biogas plants which require at least 96 sqft., thus making it space effective. CHUGG-75’s by-products are biogas, used for cooking and digested slurry, which is rich in plant nutrients and used as manure in the garden.
By converting food waste to energy, this Amma Unavagam is diverting 2000 kg of food waste per month from the landfill. From its installation in February 2021 till date, it has diverted nearly 41,000 kg of food waste from the Perungudi landfill in southern Chennai and reduced carbon emissions to the extent of 1,02,500 kg till date.
By creating its own energy source for cooking, the Amma Unavagam is also reducing its dependency on Liquefied Petroleum Gas (LPG). It has decreased its consumption of LPG by nearly 100kg per month, resulting in approximately 2100kg reduction in LPG consumption from installation till date. This translates to a savings of INR 1,81,890 (~USD 2,200) till date.
This initiative would not be as effective as it is without support from the Amma Unavagam staff who play a critical role in the day-to-day management and functioning of the system. The staff comprise of a group of 15 women who were part of the entire project cycle from pre-planning till post-project operation and maintenance. AVRIS Environment Technologies trained the women to operate the plant, manage unexpected events such as heavy rains, blocked pipes etc., and record data on the quantity of food waste fed into the digester daily. The enthusiasm and willingness of the women to learn a new technology and skill significantly contributes to the success of this initiative.
 One kg of food waste is estimated to be 2.5 kg of carbon.
 Amma Unavagams are extremely popular government canteens which serve food at extremely subsidised rates. For instance, a plant of dal and rice is Rs 5 (USD 0.06).