Those and other fascinating tidbits about the way industry gulps up the water supply were part of a study published recently in the journal Environmental Science & Technology. Considered the first comprehensive study of its kind in three decades, the report used a computer model to estimate the water use of more than 400 industry sectors.
According to the report by researchers at Carnegie Mellon University's Green Design Institute, the most recent industry-by-industry data on water consumption dated back to the 1982 census (the question was later dropped to reduce costs). The new data indicates that industry's water use is mostly indirect. For example, more water might be used in the packaging and shipping of food crops than in watering the plants.
The scientists, Michael Blackhurst, Chris Hendrickson and Jordi Vidal, said: "The study gives a way to look at how we might use water more efficiently and allows us to hone in on the sectors that use the most water so we can start generating ideas and technologies for better management."
But the researchers cautioned that their results are "subject to considerable uncertainty and underlying variability" and only apply on a national scale, rather than regional. Also, they were unable to determine how much water was returned to the system or recycled, focusing instead on withdrawals.
Some of the other findings include:
- Agriculture and power generation account for 90 percent of direct water withdrawals
- 60 percent of water use is indirect
- 96 percent of the industry sectors use more water indirectly in their supply chains than directly
- The food and beverage industry accounts for 30 percent of indirect water withdrawals
The research was supported, in part, by the National Science Foundation and the Green Design Consortium at Carnegie Mellon University.