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Water
Continue to reduce water draw-down (for million dollars of added value) by at least 5% per year, through conservation, optimization and recycling.
Water recycling: reach a minimum of 90% recycling ratio in two pilot sites by end 2005
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Clean water is becoming increasingly scarce throughout the world. In many areas the situation is already in crisis. Underground supplies are running dry and water reserves are being used up or polluted faster than they can be replenished. Almost a billion people do not have enough safe drinking water. Rapidly growing populations, especially in cities, are demanding more water than can be supplied. Shortages of clean water impact on the quality of people's food and domestic life, their health and general welfare.
Water plays a critical role in the semiconductor manufacture. It takes about 1,500 liters to make one wafer. Only ultra-clean water can be used because of the precision demanded. Conservation of water is one of our corporate goals and it is an imperative at several sites where water supplies are scarce or diminishing. We are concentrating our efforts on developing methods to reuse wastewater in manufacturing.
Much like cleaning clothes, we wash off chemicals and metal residues from our products and these impurities end up in wastewater, which must be cleaned before it is reused or released to rivers and seas.
RAW WATER CONSUMPTION
We largely met our Decalogue target, saving 45% at equal production value in the period 1994-2000.
Examples
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Our Malta plant has made dramatic improvements in water use. Actions include microfiltration to remove silicon dust after wafer cutting; using reverse osmosis ion-exchange resin to clean water from plating processes; recovery of waste brine from the Electrodialysis Reverse (EDR) water purification system - used as toilet flush water; storing of rain water; using less soft water for the regeneration ion exchange resins. The site will be the first to reach our 90% water recycling target by 2005. A second pilot site has been selected at Rennes in France. |
WATER CONSUMPTION AND % OF RECYCLING
Examples
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In our Rousset site in France the conventional technology (ion exchange) used to produce ultra pure water has been replaced with electro-deionization. This has reduced the use of chemicals (50% less sulphuric acid and 90% less sodium hydroxide). Using less chemicals has produced other benefits, including smaller storage areas, easier compliance with regulations, fewer truck movements and no polluted effluents. |
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