Chennai is gearing itself to face a water shortage this summer after seven years. Higher than average rains during the Northeast Monsoon in the last few years had put the city in a somewhat comfortable position till last year. There has been a 16 per cent shortage in monsoon rainfall during the last three months of 2012. Consequently, the four reservoirs which feed the city are only half full. Groundwater sources are fast depleting. Neighbouring Karnataka is in no mood to spare Kaveri water to Tamil Nadu for either agricultural or drinking purposes.

The population is growing fast in the city in a rapidly urbanising State. According to Census figures, Chennai's population has grown from 4.7 million in 2011 to a little over 5 million in 2012. The UNDP mandates a minimum of 150 litres of water per person per day. Chennai, therefore, requires 750 million litres per day. Industry and the transient population also need a considerable amount of water which means that the city's total water requirement is about 1200 mld. However, the Chennai Metro Water Supply and Sewerage Board, Metro Water, manages to supply on an average only about 850 mld, and that too in good times. There is, therefore, a shortfall of about 350 mld.

Much-wanted relief is now being partially provided by the desalination plant in Nemmeli, 35 km from Chennai, which was inaugurated a month ago. This plant has been planned to provide only drinking water. The largest desalination plant for drinking water in the country, it has a capacity of 100 million litres per day. In augmenting the city's present water supply by a little over ten per cent, it will serve 1.5 million people in South Chennai suburbs like Velachery, Tiruvanmiyur, Rajiv Gandhi Salai and Karapakkam.

Several units which would remove the suspended solids in the sea water were tested, and only after the quality met the required standards did the water undergo the last stage of the treatment process before being distributed to residents. This process ensured that the total dissolved solids in sea water were reduced from about 40,000 parts per million (ppm) to 300 ppm, making it fit to be used as drinking water.

"There was a lot of pressure on us to complete the project," says Rajiv Mittal, Managing Director and Chief Executive Officer of VA Tech Wabag Limited. Mittal's company constructed the plant and L&T laid a 64-km-long pipeline from the plant and built underground sumps en route. Bridges to carry pipes of diameter varying from 500 mm to 700 mm had also been constructed across the south Buckingham Canal.

Chennai has another 100mld desalination plant which was implemented on a design, build, own, operate and transfer basis by Chennai Water Desalination Limited (CWDL), a special purpose vehicle of IVRCL Infrastructures and Projects Limited and Befesa Aqua, Spain. This plant is meant to serve the water needs of the Ennore Port Trust and North Chennai thermal power plant. The good news is that drinking water is also supplied to the public during droughts.

The Nemmeli plant project cost is Rs.1033 crore, which includes a seven-year operate-and-maintain clause. The technology partner is IDE Technologies, Israel, and the technology used is the reverse osmosis process. Mittal says water from this plant will be very affordable and will be available at 2.5 paise per litre.

Desalination of sea water for drinking has become more viable in the last six to seven years, adds Mittal. The prices of membranes, which have to be imported, have come down. Costs have reduced considerably as a result. However, desalination still remains a power-intensive technology. The Nemmeli plant requires 3 to 3.5 MW of power. The cash strapped Tamil Nadu Electricity Board is committed to provide this. "We have to find cheaper power sources, as power makes up 70 per cent of the cost," points out Mittal.

With our large coast line, and agriculture taking up 80 per cent of our water resources, desalination may be the best way forward in the future.

Water treatment is the next sunrise industry, feels Mittal. VA Tech Wabag, the largest water company in India, is based in Chennai. Mittal came to India from the UK in 1996 to set up the water treatment business in India for Wabag. He acquired the Indian company in a successful management buy-out in 2005 with ICICI Securities supporting him with a 70 million euro bank guarantee. In 2007 he managed to acquire the parent company as well from Siemens. As a result, VA Tech Wabag is an Indian multinational today with a workforce of more than 1400 in 20 countries in three continents. It has a turnover of Rs.1700 crore with its top line doubling in four years and zero debt on its books. "Waste is our resource. Our bread and butter business is waste water treatment."

Mittal is confident that VA Tech Wabag will be among the top three players in the global water and waste water management business in the next five years, by when they would have moved into South America as well.