When every drop counts

A few weeks ago, the Bengaluru Water Supply and Sewerage Board (BWSSB) made it mandatory for apartments with more than 20 houses and built over more than 2,000 sq ft to have sewage treatment plants.

However, several people, both at the individual and institutional levels, have already been recycling water successfully, says water conservationist and founder of rainwater harvesting club S Vishwanath.

A R Shivakumar, principal investigator (rainwater harvesting) at IISc’s Karnataka State Council for Science and Technology, added recycling used water to his endeavours to conserve water more than a decade ago.

“Bengaluru is a great place to experiment with water recycling because the price of water here is very high,” says Shivakumar, also known as the city’s rain man as his house in Vijayanagar runs entirely on rainwater.

Water from the kitchen sink cascades down a series of cans into the garden while that from the washing machine is treated and used for toilet flushing he says.

“To wash vessels, we use a mild detergent that doesn’t harm the plants. The water from washing clothes, I have found, can be used directly to flush toilets on the same day,” he says.

However, if this water is stored for over two or three days, as is most often the case, it starts to smell like city drains because of the presence of hydrogen sulphide, he explains.

“So we treat it in a plant with the water weed cattail,” he says. “This removes the heavy metal and some organic content in the water after which it passes through two more barrels and flows down a zigzag path for aeration into a tank where it’s mixed with an equal quantity of fresh water.”

This reduces the odour considerably, he admits, though not entirely. “But it brings down our fresh water consumption by 35 to 40 per cent,” he adds.

Prithviraj K S’s Sahakarnagar house also has a similar system in place to treat water from the washing machine. “We have a loft tank with reeds, pebbles and charcoal in different chambers,” he says. “The capacity of the tank is about 200 litres.”

This water is used to flush the toilets five or six days a week, he says. “This and the implementation of rainwater harvesting has brought down our consumption of BWSSB water,” adds Prithviraj, a branch manager in an instrumentation company.

“We started recycling three years ago, when we moved here.”

Rohan Ninan Eapen’s family of four lives in a house behind Manyata Tech Park, outside BWSSB’s service limits. But they rarely suffer from water shortage, and recycling water aids in this.

“On the internet, you will find UN data that says water usage per person per day is 120 litres. But we manage to reduce our fresh water usage by 40 to 60 litres,” says the software engineer.

This house too uses a method of recycling grey water (water from the washing machine, sink and bath) that’s similar to Prithviraj’s. “We’ve noticed that the efficiency of the root systems of the plants that purify the water is reduced by the phosphates and other chemicals in the regular detergents,” he elaborates. “So we make our own using soapnut.”

Programme manager Rohit S has the water from his bathroom flow directly into the garden of his house in Basaveshwaranagar. “This is just soap water, which isn’t harmful to many plants,” he believes.

Several apartments have also implemented it, says Vishwanath, and there’s a 1.5 MLD plant in Cubbon Park run by the BWSSB, water from which is used for drinking.

“The terrace is a great place to treat water,” the expert adds. “While the activated sludge process, which involves separating the sediment and purifying the water, is the most popular, several other options are available, thanks to advancement in technology.”

So for those who haven’t started yet, perhaps, there’s no time better than the present. For, as Rohan says, water is the elixir of life.