BANGALORE : Scanty monsoon, falling water levels in reservoirs and grave power crisis. In this scenario, flushing Cauvery water down your toilet is criminal. That's what the Karnataka State Pollution Control Board (KSPCB) thinks too. In the first step to curb this, it has made dual piping mandatory for new layouts and apartments, saving up to 40% of potable water.
While residents can use potable Cauvery water for drinking, washing utensils and bathing, the other pipe will bring in treated or rain water to be used for lawns, toilets, washing cars, floors, etc.
KSPCB chairman H C Sharathchandra told TOI almost all new apartments have in-house water treatment units. The treated water can be reused for plants, lawns, flushing, cleaning and others. "It doesn't cost much but saves up to 40% of potable water. Since apartments also have very efficient Effluent Treatment Plants (ETPs) with reverse osmosis (RO) and membrane technology, there is no question for concern. They can very well use this bacteria-free water for secondary uses," he said. Many new apartments in Sarjapur, Whitefield, etc. have incorporated these units. An apartment complex in Malleswaram also has RO technology.
According to research associate, The Energy and Resoource Institute (TERI), M N Sridhar Babu, rain water can also be efficiently used through dual piping if the housing block doesn't have an ETP. "Due to climate change, our rainfall pattern has changed a lot. It's very unpredictable so there's flooding sometimes. This is intensified because all our roads are asphalted and water doesn't seep into the soil. Even with worst kind of roofing, we can capture 75% of rain water and use it through dual piping. This will address flooding as well," he said.
Even a small leak in the pipes leads to a wastage of 12,000 litres of potable water. There are thousands of such small leaks all over the city and the wastage is enormous, says Babu. Dual piping can be done in old apartments or houses as well, with metal or plastic piping and the payback period is between 2 and 4 years. However, he said the technology is not mature enough for the treated water to be used for bathing or cleaning vessels. Less than 20% of the population is currently using dual piping voluntarily. "The potable water saved should be given to the needy who most often get contaminated water. It's not a complex process that cannot be implemented," he added.
