Rainwater harvesting makes news every day. But conservation and recycling of water is equally important. Taj Air Caterers in Chennai shows the way
The United Nations Environment Programme (UNEP) says that water stress -- shortages, floods, pollution and damaged ecosystems -- demands radical new approaches to the use and management of water resources.
"We have a 19th century approach to 21st century problems," said Domingo JimAcnez Beltrn, Executive Director of the European Environment Authority that works with UNEP on water conservation issues, "We just think of supplying new dams and pipelines ('megalitres') rather than increasing water use efficiency ('negalitres'). Prices don\\\'t cover the full cost of supplying and using water, which encourages its inefficient use. An integrated approach to water quality and quantity is needed."
Negalitres refer to demand side management which focuses on the more efficient use of water by reducing losses, less wasteful use of water, more efficient appliances, and water recycling. UNEP says that in many cases it is cheaper and more effective to improve water use efficiency than it is to increase water supplies. For example, water efficiency measures reduced the consumption of water in Madrid by 25% between 1992 and 1994. This is the equivalent of a reservoir providing over 100 million litres of water per year.
According to another estimate, the use of 6-litre toilet water flushes in the UK, rather than the usual 9 litres, would save 10% of the UK\\\'s household water use. The prices of nitrates and pesticides on agricultural land do not include the full costs of their use, such as their pollution of groundwater and the expense of treating these potential drinking water supplies so as to meet EU water quality standards. Water quality and quantity are linked. For example, polluted water can reduce available supplies.
While rain water harvesting makes news on a daily basis, little attention is being paid to the issue of conserving and recycling water. When we use less, we need less. And vice versa. It is economically viable and easily possible. Taj Air Caterers is one thriving example of how water can be economically recycled.
Taj Air Caterers is a sprawling facility that can be best defined as a food factory. Meticulously maintained to international standards of in-flight hygiene, TAC employs hundreds of workers and works round the clock in a business that never sleeps. A joint venture of Taj Group of Hotels, SATS of Singapore and Malaysian Airlines System, the unit has a built-up area of 88,000 sq ft on a plot measuring 2.5 acres. TAC started its operations in the perennially water-starved city of Chennai in July 1999. The enterprise is designed and equipped to handle the preparation of 12,000 meals per day. Its present output of 7,000 meals every day caters to the needs of eleven domestic and international airline carriers.
TAC is located a stone's throw from the city's airport, in Pallavaram. This falls outside city limits and therefore does not have piped or tanker-delivered supply from the Chennai Metropolitan Water Supply and Sewerage Board (the government-owned public utility). For that matter, not being under the purview of the Corporation also means that the area has no centralised or inter-connected drainage system. Sewage in such localities flows into little nullahs (drains), open and untreated. In the middle of all this, TAC is nothing short of an oasis of self-sufficiency and sustainable water conservation.
Says M F Havewala, chief engineer, "At the Taj Group of Hotels, we have a very old tradition of caring for the environment and natural resources. Water is given prime importance."
During the design stages itself, it was decided to install a Sewage Treatment Plant (STP), which could treat all the wastewater generated by the facility. Grindwell Norton of Bangalore designed and installed an STP as per the specifications provided by Taj. The apparatus can treat 3 lakh litres of sewage water per day. As of now, around 2 lakh litres of effluent water are generated, and efficiently treated, every day.
All the wastewater from all the areas in the establishment, except the 'hot kitchen' and 'pot wash' departments, is fed to the STP directly. Says Havewala, "Drain water from the hot kitchen and pot wash areas is passed through a grease trap to remove oil and grease and then fed into the STP for recycling treatment. We do not use any chemicals for speeding up the process."
The sewage treatment plant uses an aerobic system for separating solids from the water. The treated water, which is separated from solids/sludge, is fed through a tertiary treatment plant consisting of dual media filter and activated carbon filter units. This treatment removes the turbidity, odour and taste from the water. The water coming out of this tertiary treatment plant is injected with a dose of chlorine to a value of 0.5 to 1.0 ppm. This water is crystal clear and microbiologically fit for human consumption.
However, says Havewala, "Due to the nature of the business (high security with ultra-cautionary parameters to prevent food contamination) this water is not brought inside the building even for washing purpose. The recycled water is exclusively used to water the gardens around our premises."
The large red building with a brickwork facade is surrounded by about 26,000 sq ft of developed gardens. Leftover water is used as 'make-up' water for the cooling towers of the firm's air-conditioning and refrigeration systems. The sludge which remains behind is fed into a filter press where it is compressed in cake form. These sludge cakes are used as organic manure for the garden.
Says Havewala, "As the Chennai region is always water scarce, we decided to install a rain water harvesting system during the project stage itself." All the storm water drains which bring down rain water from the terrace are diverted into specially-made chambers. These structures have 15 feet deep percolation pits in which PVC pipes of 8" diameter, with vertical slats, have been inserted.
The company even takes into consideration the natural wet spells, when the garden does not need watering and the cooling towers do not need 'make up'. The recycled water generated by the sewage treatment plant is then fed into the percolation pits of the rain water harvesting system, going towards the replenishment of the underground water table.
Says Havewala, with not a little pride, "Only a small percentage of water is lost due to evaporation, while being used in the cooling towers or while sprinkling the lawns. Thus, virtually all the water which is used for the operation of this unit is returned to its place of origin. If we didn't have a sewage treatment plant running efficiently, precious recyclable water will flow out to the sea, causing water pollution and resulting in a tremendous loss of revenue."
TAC needs a minimum of 150 KL (kilo litres) of water every day to maintain its gardens and operate the cooling towers. At an average rate of Rs 45 per KL, the cost of water for these functions alone would have been Rs 6,750 per day, totalling a whopping Rs 20,00,000 per year (discounting the average number of days on which it rains). TAC spent a total of Rs 12,00,000 on the sewage treatment plant. This amount was recovered in less than an year of its operations. Smiles Havewala, "From then on, it has been just savings of precious resources, both money and water!
Contact: Taj Madras Flight Kitchen Pvt., Ltd.
No.6, Officers Line
# 272 GST Road
Telephone Nos.:044-22561120 to 22561124
InfoChange News & Features, August 2003