Think for a moment of a microchip -- that little piece of silicon that practically runs the modern world. What comes to mind? Computing power? Speed? Complexity? Money, perhaps? But how about water?
Few people realize that building each of the billions of tiny computer chips in the world takes anywhere from three to eight gallons of water. To visualize the thirst of the industry, imagine a football field, dug 10 feet deep and filled with water so pure that even water used in a surgical theater wouldn't qualify. That's the amount a single chip factory can use in a single day -- as much as the average household uses in 40 years. Paradoxically, many chip manufacturing plants currently operate in arid places like the Southwest United States, which has been locked in a decade-long drought.
And the industry is booming. The ever-increasing market for cell phones, talking plush toys, and car engine computers has pushed the demand for chips (and the water to make them) higher and higher. For years, environmentalists have worried that chip production would bankrupt already strained water tables around the world. But it turns out that by embracing their critics -- hiring environmentalists as water engineers and planners -- the industry may have reversed the trend. Saving water and pinching pennies can, it seems, go hand in hand.
Creating a computer chip -- be it for a laptop, camera, or microwave -- is like building a skyscraper one floor at a time. With each microscopic addition, manufacturers grow a bed of material in thin layers similar to rust and then etch tiny canals, creating a complicated maze that shuffles electricity here and stops it there. But when the manufacturer adds floors to the building, it needs to rinse off the excess bits from the last layer. The standard practice has been to dunk an eight-inch wafer of chips in a tub of water. And as chips have become more sophisticated, they have increased in layers and required more rinses.
This is essentially why companies such as Intel ran into problems when they first set up shop in the Southwest in the early 1980s. According to Ted Smith, founder of the Silicon Valley Toxics Coalition, which monitors the environmental performance of the computer industry, "they ran into a buzz saw of opposition" from farmers, communities, and local water boards. Smith says chip manufacturers held bidding wars among local governments for the sweetest economic deal; if that came from an arid place, they bought up all the water rights they could from desperate farmers. Industry representatives admit that water was so cheap, and the investment conditions so favorable, that they gave little thought to conservation.
Over the past decade, however, a mix of environmental and market pressures has forced an industry-wide rethink. SEMATECH, an organization formed by chip makers to monitor themselves, claims that water use dropped 40 percent across the industry between 2001 and 2005, with some factories recycling 80 percent of their water. "It's a cost-driven thing," says Walter Worth, a water expert with SEMATECH. "Memory chips used to be $200; now they are down to $2. So to keep on producing [them] you really have to be efficient."
Fifteen years ago factories simply tapped the local water supply, purified it, used it, and flushed it down the drain. Today, engineers realize that even after running through the factory, wastewater is cleaner than newly purchased water. So in an industry where every dollar is a potential competitive edge, recycling has come into favor. There are other ways to save water too. Most companies now spray down chips with a hose rather than dunking them in tubs, calculating the minimum time needed to get the chips clean. And with today's bigger, 12-inch wafers, the same number of chips needs about 50 percent less water.
Smith is quick to question the industry's cheery numbers. He's concerned that U.S. factories only seem more efficient because much of the work has been outsourced to Asian contractors. Solid outsourcing numbers are notoriously hard to find, but according to some estimates, more than half of U.S. chip makers now operate overseas, mostly with smaller manufacturers.
Todd Brady, a global environmental manager at Intel, denies that water conservation practices in overseas plants are any different from those used in the United States. In many developing countries, he argues, water quality is so low and purification costs so high that it is cheaper to use recycled water.
And some Asian countries are even ahead of the curve. Stiff water regulations forced Taiwanese plants to recycle 80 percent to 90 percent of their water long before U.S. plants did so. In Singapore, more than 90 percent of the 24 million gallons of sewage water recycled each day goes into chip-making.
In the end, it comes down to what makes the best business sense. In the high-tech world, companies like to see investments turn around in 18 months. Water conservation efforts can pay for themselves in as little as two and a half months. Brady says Intel's Arizona operations have cut their water needs from five million gallons a day to one million.
Many even think the industry is moving away from water altogether. Instead engineers are considering the idea of cleaning chips with ultrahot plasma (a gaslike substance akin to what fuels the Northern Lights), made from various mixes of oxygen, hydrogen, argon, and carbon dioxide. Benjamin Franklin once said, "When the well is dry, they know the worth of water." In the cutthroat world of computers, perhaps Franklin's philosophy can keep a little more of our precious water in the ground.
-- Erik Vance
