S. Vishwanath says that if waste water treatment plants are located well, they consume less energy and produce water good enough to be used for landscapes and for flushing toilets
The city is faced with a massive challenge when it comes to treating waste water. Of the 1,000 million litres per day of waste water generated, only about 430 million litres gets treated every day. Stormwater drains are thus full of sewage and this ends up in our rivers, lakes and groundwater.
Under a new set of projects, additional waste water treatment plants are being put up yet they may prove to be inadequate. On the other hand, when one looks at smaller waste water systems the city has more than 2,000 of them, according to Anant Kodavasan, member of an expert committee looking into the issue. Many of them are however are either dysfunctional or are performing below par. The installed capacity of these systems are close to 200 million litres per day, a significant volume.
The best bet is for all the apartments and institutions that have these plants to get them evaluated and brought into efficient performance levels. The cost of the treated waste water ready for use as non-potable water could vary from Rs. 18 to Rs. 30 a kilo-litre, significantly less than the water being purchased from private water tankers.
The State Pollution Control Board insists that every apartment or layout which has more than 80 flats must have its own waste water treatment plant. If these plants are located well, not hidden in basements, they consume less energy, treat water well and produce quality good enough to be used for flushing toilets and for the landscape. A systematic re-evaluation of these plants is therefore necessary to fit them into the overall strategy of managing wastewater in the city.
The other advantage with these systems such as the one in the Jayadeva Institute of Cardiology, a hospital in the southern part of the city, is that they produce not only treated waste water for reuse but also other by-products such as biogas for cooking and bio-sludge manure for gardening. As Dr. Ravishankar, the designer of the system, explains, “These plants not only look good, there is no odour and there is no waste. All by-products are reused and the system pays back for itself in about four-and-a-half years.”
With some treatment plants there is an excess of waste water available on site. A system of sharing between apartments has to evolve and a market for its distribution created. ITC-Windsor Manor for example is able to give its treated waste water to the golf club opposite it since it has more than its requirement. These markets need to evolve further and should be facilitated by the BWSSB and the Karnataka State Pollution Control Board.
Apartment owners, layout residents and institutions are doing the right ecological and economic thing by installing these WWTPs for not only do they save money, they ensure that the environment is not polluted. Investing in R and D, developing better models for operations and maintenance and better consumer education will go a long way in ensuring better water management for the city.