CHENNAI: Stories about water reserves having dried up, crippling lakhs of lives in different parts of the country, including Tamil Nadu, are common in the news these days. In contrast, the Indian Institute of Technology Madras (IIT-M), has an inspirational story to tell. Though the Chennai Metropolitan Water Supply and Sewerage Board (CMWSSB) has cut the supply by half, the premier institution is facing no crisis and, in fact, has excess water at its disposal that is being diverted to fill waterbodies on the lush-green campus. There are even plans to sell it!
IIT-M has desilted the freshwater lake, which has the capacity to store 180 million litres, taking inflow from storm water drains, so, not a drop of rainwater is wasted. In January, IIT-M commissioned a state-of-the-art 4 MLD (million litres per day) Sewage Treatment Plant (STP) using the latest Sequential Batch Reactor technology which treats raw sewage to drinking water standards. A fully-automatic Treated Water Distribution System has been laid with 20 km long pipelines connected to every household, hostel and academic block. This enables optimum utilisation of treated water.
The flushing, gardening and air conditioning, which accounts for 40% of total usage, is taken care of by treated water.
IIT-M has a population of about 20,000, of which 9,000 are students (an equal number are residents) and a floating populace of 2,000. The institute’s one-day requirement is 2.8 MLD and the CMWSSB supplies 1.2-1.8 MLD. The gap is being bridged by tapping local freshwater resources and waste water recycling.
Speaking to Express, Ligy Philip, Chairman (Engineering Unit), IIT-M, says: “We have a freshwater treatment plant near the lake which can supply 0.8 MLD for drinking purposes.
The STP treats close to 30 lakh litres per day, including 8 lakh litres of waste water generated by the IIT-M research park. We send back 8 lakh litres of treated water to the research park for their utilisation and 10 lakh litres is routed for flushing and upkeep of greenery. So, the remaining 10-12 lakh litres is in excess, which is being diverted into ponds. Once those are full, two groundwater recharge wells are dug up, each having a capacity of 0.5 MLD. This will replenish the fresh water lake. Overall, nothing is wasted,” she explains. Philip adds that IIT-M is looking for buyers for the excess treated water.
A visit to some of the facilities in the campus is enough to understand how successful its water distribution system is. Ponds are full, with fish and birds flocking the vicinity. The lawn area, cricket ground and newly inaugurated Manohar C Watsa Stadium bears no sign of drought.
D Rajavel, assistant executive engineer, IIT-M, says the infrastructure should hold strong for the next 50 years. “A decade back, the demand for water was 1 MLD, but now it has gone up to 2.8 MLD. It would be extremely difficult to maintain such a large campus otherwise,” he says, before adding that the entire mechanism was realised in the last three years, in a phased manner, at a cost of about `20 crore.
Treated water quality
As per new Central Pollution Control Board (CPCB) norms, these are key parameters in accessing the quality of treated water. IIT-M’s STP has fulfilled all key parameters and has extra UV filtration and ozonation to kill any pathogens or bacteria.
Back-up plan
IIT-M has 6 open wells and 12 borewells, which are not yet used. It has permission to draw 4 lakh litres per day from these sources in case of need. Ligy Philip, Chairman (Engineering Unit), said water can be drawn from the lake till June end. In July, the demand will shoot up to 3.5 MLD since new students and parents will arrive. All hostels, guest houses will be full. So, necessary arrangements have been done for that as well.