In 2014, engineer Shahzeen Attari asked 457 university students to draw a picture of how they thought water reached the taps in their homes, and where it went after that. Nearly a third of the diagrams missed the water treatment plant, and almost two-thirds forgot the wastewater treatment plant. On one, the pipes going into the house were labeled “magic.”
Most of the time it does feel like magic. But Attari, an associate professor at Indiana University who studies the psychology behind energy use, wants to see a better public understanding of the mechanics behind the mystique. “If you don’t understand it, you might not value it,” she says. “And if you don’t value it, you might not understand why it’s important to conserve.”
Every time we turn on the tap, we run up not only a water bill, but also climate emissions. Two percent of all electricity use in the United States goes toward pumping and treating water and wastewater. A 2005 estimate put the carbon emissions from public water and sewer systems, and wastewater treatment, at about 65 million metric tons annually. Heating water once it’s inside homes adds another 169 million metric tons of carbon emissions. Combined, that’s equivalent to the emissions from about 50 million cars driven for a year.