Thane society combats water scarcity with sustainable solutions

A man fills his bucket with condensate water from air conditioners; (right) the common pipe where the condensate water is collected

As Mumbai faces a 10 per cent water cut and dwindling potable water in its reservoirs, BMC has resorted to using reserve stocks. Residents of the Saprem Co-operative Society in Thane are now creating sustainable solutions to combat water scarcity. For more than two decades, the residents of the 64-flat society in Lokmanya Nagar have struggled with frequent water disruptions forcing them to rely on expensive water tankers costing up to R1 lakh per month.

Preventing wastage

"In 2019, we dug a borewell. Before passing the resolution, the committee presented the calculation of how much-filtered water was being wasted. On average, one person uses the washroom at least four times a day, consuming 20 litres of water. For a household of four, this amounts to 80 litres. For the entire society, this means wasting 5,000 litres of water. Such wastage was unacceptable resulting in the passing of a resolution of digging a borewell," said committee members.

Saprem Co-operative Society in Thane

"When we drilled the borewell, we found water at a depth of 340 feet. This solved the water problem as water was available 24 hours. However, the long-term sustainability of the groundwater source remained uncertain. Today, in the concretised world, there is hardly any scope for rainwater to seep into the ground. Instead, it is often seen getting flushed out in drains. Determined to find a solution, we implemented rainwater harvesting by constructing a shed on the building's terrace," the committee members added.

Avinash Shaligram, secretary, and B.B. Bhise, chairman of Saprem Co-operative Society, told mid-day, "We struggled a lot with water disruption. But with the unique ideas and cooperation from the residents, we came up with this rainwater harvesting plan, which we have been implementing for the last three years. Why waste this natural rainwater, which can be diverted for a meaningful purpose?" said Shaligram.

Shivani Gaikwad, who has resided in the society for 20 years, told mid-day, "If there is no water, it becomes difficult for women to manage all household chores, and frustration becomes evident. As a working woman, I went through that struggle. We used to receive a message from the society committee that water would come only for 15 minutes. But I can proudly say that our society is not facing a water problem as we have taken sustainable steps to reuse the water."

The society also initiated the reuse of condensate water from residents' air conditioning units. A dedicated pipeline collects and channels this condensate water, which is then used for washing vehicles, watering plants, etc. "In summer, AC usage is high, and the condensate water is being wasted. We installed a common pipeline for ACs to collect this water. At the bottom, we placed a 5-foot-long, 4-inch-wide pipe which serves a capacity of approximately 753 litres. We also attached a tap, allowing the collected AC water to be used for washing cars and watering plants," said a resident.

Experts speak

Nazibur Rahaman, an AC engineer with BlueDart, told mid-day, "Assuming each AC is run for an hour, which is not the actual case as ACs are usually run for at least two to three hours, each AC will be producing 1 litre of condensate water. Taking into account 60 houses, the ACs will produce 60 litres of water in an hour. This means even if the ACs are used for 3 hours, the amount of condensate water generated is 180 litres."

"Even if we use a 10-litre bucket for washing one car, which is more than adequate water, 18 to 19 cars can be washed with the amount of condensate water collected by just 60 one-tonne ACs running for three hours," said Rahaman.

He added, "I am not exactly sure about the number of cars or four-wheelers in Mumbai, which are washed every day but let us consider this number to be one lakh. Though the number will be much higher. So, on average, Mumbai wastes approximately 10 lakh litres of water just for washing cars every day. If we assume everyone uses a 10-litre bucket for washing one car and the number of cars washed every day is one lakh.

Instead, if this sort of repurposing of the AC condensate outlet water is being implemented in all societies, we can at least make sure that 70 per cent of the 10 lakh litres of filtered municipal water wasted on washing cars is saved every day.