Growing up in Kerala’s Alleppey – a place surrounded by plenty of water, and then suddenly moving to Bengaluru – a city where he paid for every drop, Prabhath Vijayan became conscious of addressing water depletion.

For this, he has made a simple system to reuse the discharge water from his RO water purifier at home. He says ROs use reverse osmosis to purify water. For every 5 litres, they give one litre of purified water and four litres of wastewater.

He notes, “The groundwater level in the city is depleting every year. It is our responsibility to minimise this.”

“When too many RO purifiers are set up in the same area, especially in bigger apartment communities, the water wastage is higher, unless the wastewater discharge is put to use somehow,” he adds.

He devised a simple setup that ends up saving 24,000 litres of water a year – the minimum usage of a three-to-four-member family.

Prabhat says that a minimal setup requires only a drum, which costs Rs 300-500. For this, he found an unused 50-litre drum and placed it in a 2 sq-ft utility area of his house.

Using a screwdriver, he dug a hole in it to put in the discharge pipe from the RO. The wastewater from RO is collected in the drum and used for household purposes like washing, cleaning, outdoor gardening, etc.

Talking about the impact of his initiative, he says, “Around 2014, the water hardness level in our area was around 600 ppm [parts per million]. Now the water we get is 800 ppm.”

“The water levels are below 1,000 feet. One tanker of water costs a minimum of Rs 1,000, and by installing an RO, we have saved more than 40 tankers worth of water, and thereby, the expense,” he explains.