New Delhi: In the battle against India’s worsening water shortage, Indian industries have begun to transform the way they use and reuse their own water supplies.

They are responding to increasing pressure from water experts. At the 2011 Water India forum in New Delhi, Arjun Thapan, special senior adviser on water and infrastructure to the Asian Development Bank, called the situation in India “unremittingly bleak", telling the representatives of industry gathered before him that they must change the way they use water if they want to avoid a “train wreck".

“Frankly, I do not believe that India has a choice; it must reform," said Thapan. “India’s demand for water in 2030 has been estimated in recent studies to be about double that of China’s: 1,500 billion cubic metres compared to 818 billion cubic metres in China."

Conservation plan: A water treatment plant at the Maruti factory in Gurgaon. According to the company, water consumption per vehicle has fallen by 62% since the implementation of its water policy in the early 1990s. Pradeep Gaur/Mint

Other experts agree. In 2004, industry accounted for 22% of global freshwater consumption, according to the UNDP’s World Water Development Report of 2003. By 2025, that percentage was expected to double. Further, most of the increase in industrial water use is likely to happen in fast-developing countries like India. And as manufacturing industries migrate to developing countries, the pressure on the water sources of those countries will only intensify.

In the light of these facts, Thapan urged Indian businesses to respond enthusiastically to a “multi-billion dollar market which is largely unserved". Major industry elements should develop on-site pre-treatment facilities to treat and reuse the waste they generate, he said. This would reduce the reliance on groundwater, a particularly stressed water source in the megacities and industrial zones.

Though progress has been slow, some manufacturers have made significant reductions to their water footprints. Car maker Maruti Suzuki India Ltd started a waste water programme in the early 1990s and achieved a zero-waste discharge by 2003. That means no water leaves the site in Gurgaon; all water used there, be it effluent, sewage or rainwater is cleaned and pumped back into the system.

As a result, the manufacturing plant can make some impressive claims. Water consumption per vehicle has fallen by 62% since the implementation of its water policy and deputy plant manager L.N. Rao said that the measures adopted have reduced fresh water consumption by about 35%.

The system is both comprehensive and complicated. The water treatment plant at the heart of the 300-acre complex is the nerve centre of the system. It controls everything from the demineralization of freshwater for the spray guns in the paint shops to the acid dosing of effluent to restore its PH balance.

The plant takes its fresh water from a nearby canal that’s an offshoot of the Yamuna. Before 1994, it relied on groundwater from a borewell, but Rao said that the serious depletion of that resource gave the company pause for thought. Borewells still exist but they are now only marginally used by Maruti, to keep the pumps from silting up.

At present, Rao said that the Gurgaon plant consumes about 3,500 cubic metres of freshwater from the canal per day (the government limit is 190 cubic metres per hour). A little less than half of this is cleaned, chlorinated, ozonated and used for drinking. The same amount (1,500 cubic metres) is piped around the site for various cooling processes by air washers. The waste from the workshops is then pumped back to the treatment plant for cleaning and reintroduction to the system. A huge tank separates physical particles from the effluent, and pumps the cleaned water away for various chemical adjustments. The remaining sludge is reduced down to dark grey sediment, a mixture of chromium, lead, old paint and other factory waste. Sludge trucks fill at a rate of two a day and the waste is dumped in the hazardous waste pits on site. Water that cannot be cleaned for drinking is used for horticultural purposes, as is solid sewage waste. The factory has 170 toilets and treats sewage at a rate of 60 cubic metres per hour.

Although the improvements have been gradual, according to Rao, they are ongoing. “There is not much incentive for a manufacturer to do this," he said. “It was only about environmental awareness for us. Individually, we look at each process in the plant, for example the welding guns for making the body of the car need to be cooled, so we have air cooling towers which save water. They take electricity but water conservation is more important. We are looking at using more efficient blades for them now."

“When steam condenses, we reuse that water too. Heat from the incinerators is used to make more steam and then the steam is channelled back into the factory. We call these ideas ‘kaizen’, a Japanese term meaning continuous improvement."

Rainwater harvesting lagoons have also been built— dug out areas of trees and hollows that, when it rains, can collect up to 15,000 cubic metres of water from gutters all over the site, which slowly trickles back into the ground and sustains the water table. Rao estimates that the ground water level is currently at 50-60 metres and dropping at a rate of 1 metre a year, even with the lagoons’ contribution.

Rao, who has worked at the plant for almost 30 years, believes that the long-term rewards will be significant. “We are the best in the industry as far as India is concerned," he said. “Whatever costs we are paying today will be made up in the future." However, he acknowledges that there is more to be done. The next focus, he said, will be to reduce the amount of drinking water that is consumed by 10 or 15%. He believes that much of the current volume is wasted.

“The concern today is water," he said. “It’s scarce and it’s becoming more expensive. Whatever we are doing so far is not enough, but we are continually finding new ways to improve."