Americans have no idea how much water they’re using

"I'd estimate that's about 10 ml of water."

EPA

How much water goes swirling down the drain when you flush a toilet? How many gallons does it take to fill a hot tub? Most of us, it turns out, have no idea. A new study in PNAS finds that Americans have some major blind spots when it comes how we use water and how we can best conserve it.

Shahzeen Attari, a researcher from Indiana University, surveyed more than 1,000 people living in the US about their perceptions of water use. The participants were recruited via Amazon’s Mechanical Turk, a crowdsourced marketplace for work; each was given $3 of Amazon credit for completing the survey.

First, the participants were asked two open-ended questions: describe the single most effective thing they could do to conserve water, and describe the single most effective thing that Americans in general could do to conserve water. And despite the obvious similarity between these two questions, two very different answers emerged. Regarding their own water conservation, most people recommended “curtailment” strategies, or small ways that they could cut their water consumption (such as taking shorter showers or turning the water off when brushing their teeth). But for other Americans, the participants tended to recommend more major “efficiency” actions such as replacing appliances with water-efficient versions.