Chilled purified water ready to drink whenever you have a bottle and a two-rupee coin ready. Calcutta's first Water ATM has been such a success in its 45 days of service that the government has decided to install such kiosks at several universities and hospitals across the city.

"The Water ATM offers the same quality of purification as bottled mineral water, but at a fraction of the cost," minister Subrata Mukherjee said the kiosk that was inaugurated in his backyard, Ekdalia Road, before Puja. In the first 12 days of operation, the machine earned Rs 25,000, indicating usage of 12,500 times.

The user will need to bring a bottle of at least one litre capacity to hold the water that will pour out once a button is pressed and a coin inserted in the slot. "I did not want the jalachhatra model of having a glass chained to the tap as many people are averse to drinking from used glasses. Using one rupee coins for payment also posed a problem as they are available in three types and therefore were difficult for the machine to sense. So we settled for Rs 2. The money will be collected by the maintenance agent," Mukherjee added.

According to the minister, to install a Water ATM one needs space, uninterrupted power, source of water, personnel to open and shut the kiosk gate and proximity to a laboratory for periodic testing of the quality. A reservoir is dug underneath for storage of about 3000l water that is pumped in from the source while another reservoir stores 1000l overhead.

The Water ATM is targeted at arsenic-hit pockets of rural Bengal. "In the city, we are running it as a pilot project. Once a favourable report comes, we will order about 200 more machines," said the public health engineering cum panchayat and rural development minister. He named JU, RBU and CU among the next round of chosen sites. The machines will also be installed in the four big government hospitals - SSKM, NRS, Medical College and RG Kar. "We want to include some city colleges and Dakshineswar temple too," he said.

Letters are being dispatched to the authorities seeking space for installation. The vending machine, along with the gated kiosk, takes 14ftx10ftx10.5ft space and is connected to the supply line.

The project has already taken off in North 24-Parganas. "We have installed the water dispensers in 68 schools," said Md Tanvir Ahmed, managing director of Harbauer India, a German environmental engineering company. "There the water is free but the machine does not have a chilling unit because of power supply. The focus is on purification," he added.

"Children bring empty bottles from home to fill up and sometimes even take a refill before going home," Mukherjee added. In the city, too, it is proving to be popular. "Guardians of South Point School nearby regularly use the kiosk," said Ahmed.

Chief minister Mamata Banerjee has visited the kiosk and named it Prandhara.