When most of us think about how we use water, we think about watering our lawns, brushing our teeth, taking a shower or even just enjoying a cold glass of water on a hot summer day.
What we don’t consider is the indirect or virtual water that we consume — water that is used every day to produce the food we eat, the energy we use, the products we buy and the services we count on. Some 95 percent of the average U.S. resident’s water footprint is comprised of virtual water, and worldwide, the annual global trade in virtual water is said to exceed the water in the Nile River 10 times!
Below are six common ways that most of us use water without even realizing it:
- Wearing clothes. Did you know that cotton consumption is responsible for 2.6 percent of global water use? That’s not to pick on cotton unduly, of course, since all fabrics require the use of water to move from fiber to cloth. Dyeing accounts for much of the water used, whether the shirt is rayon, polyester, nylon or a blend.
- Getting around. It takes about 32,000 gallons of water to manufacture the ton of finished steel that is used to make a car. Count on about 13 gallons of water to produce a single gallon of gasoline to make the car go.What about if you ride a bike? It takes almost 500 gallons of water to produce a 30-pound bicycle — not to mention that you’ll want to fuel yourself with some extra water, especially during a summer like the one we’re having this year.
- Eating and drinking. The classic fast food “value” meal — hamburger, fries and a drink — is just one example of how much water is used to produce the things many of us eat and drink every day. The U.S. Geological Survey estimates that such a combo uses about 1,500 gallons of water — enough to fill a small swimming pool. Even a simple cup of coffee requires the use of about 55 gallons of water, most of that coming from the water used to grow the beans.
- Computing. Manufacturing a laptop computer requires water equivalent to that used to wash 70 loads of laundry in a standard machine. Making a desktop machine requires some 1,500 gallons. Indeed, the production of computers and other IT products — starting at the microchip level — demand vast quantities of water. For example, did you know that every microchip factory must process “regular” water into the “ultra-pure water” necessary to make semiconductors for everything from MRI scanners to greeting cards?
- Reading, writing and printing. The advent of e-mail and other information technology prompted a lot of talk about the possibilities of a “paperless” society, but we don’t seem to be getting there very quickly. The average U.S. resident used 512 pounds of paper in 2009 (the most recent statistic available from the American Forest and Paper Association), and it takes about 1,160 gallons of water to make a pound of paper.
- Turning on the lights. Thermoelectric power plants — fossil-fueled or nuclear-fueled facilities that use steam to turn turbines and produce electricity — generate much of the electricity used in the United States. Large volumes of water must be used for cooling in these plants, which explains why water use for thermoelectric power accounted for almost half of total water withdrawals in the United States the last time the statistics were prepared. Do you think about water while watching your flatscreen?
Given how interconnected water is with nearly everything we do, it can be tempting to throw up your hands when looking at virtual water. Fortunately, there are things that individuals can do to reduce their water footprint. In my next blog entry, I’ll provide a few ways to get started.
Dennis Nelson is the President and CEO of the Project WET Foundation, a Montana-based water education organization active in all 50 states and more than 50 countries. With a strong belief in the idea of “water for all water users”, the Project WET Foundation seeks to teach children, teachers, parents, corporations and communities about the best ways to preserve, protect and manage our most precious natural resource, water. Learn more at www.projectwet.org.