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| Human World on Mar 22, 2012

Charles Fishman on our hidden water use

Watching your flat screen TV uses water. So does running your computer. Fishman talked about water use that we might not think about – or even know about.

We might not be aware of how much water we use every day. That’s according to Charles Fishman, investigative journalist and contributing editor at Fast Company. Fishman interviewed dozens of water experts around the world for his book, The Big Thirst. He told EarthSky:

Especially as people rise to the middle class, and in developed nations, there’s lots of hidden water use. An example is, in the United States, the average person, over the course of a day, uses 99 real gallons of water.

That is, 99 gallons of water for cooking, cleaning, and bathing. He talked about water use that we might not think about, or even know about.

Photo Credit: Argonne National Library

The electricity that each American uses just at home, just residential electricity per person, that electricity requires 250 gallons of water a day. So you use more than twice as much water just to keep your computer and light bulbs running and your refrigerator and your flat screen TV running as you do to actually take a bath and clean the dishes and go to the bathroom.

Fishman said challenges to our water supply will grow this century because of the effects of climate and a growing population.

In most of the the developed world, he said, we never think about our water supply – what’s required to get it to us, what’s required to clean it, what rainfall we’re depending on. But, he said, Australia is one portion of the developed world that does not take its water for granted. Fishman said:

As climate change takes hold, and in places with water scarcity, there’s no question about changing rainfall patterns. Australia is an example of a whole country that literally almost rain out of water because the rainfall pattern going back a hundred years – the colonialized history – shifted. And so the reservoirs and the rivers, and all the places people were used to getting their water from didn’t have the water that societies had become accustomed to…. As one elected official said to me: the reservoirs were built in all the wrong places.

Almost every Australian city has, at least temporarily, solved it’s water shortage, he said. Australia now converts ocean water into potable water. He said:

Almost every city has, at least temporarily, solved its water shortage by building huge expensive desalinization plants, reverse osmosis plants, Sydney-sized plants, where the guts of the plant cover a football field or more. And those work great, but they’re incredibly energy intensive, and so they’re expensive to operate, and they may contribute to what caused the problem in the first place…that is, you’re burning a bunch of fuel, and that causes climate change.

Reverse osmosis takes so much energy, he said, because water needs to be pushed through filtration membranes at very high pressure. It takes a lot of energy to build that pressure. To try to solve that problem, he said that experts at IBM are working right now on trying to filter water using carbon nano-tubes – very, very tiny carbon tubes – that would only require water to flow through them, not be pushed.

The better we understand our hidden water use, he said, the easier it will be for the public to make smart decisions about water use and conservation.