The obvious contributors to our water footprint are washing clothes and dishes, cooking and bathing. But the biggest contributor to our water footprint is our diet.
On average, the water we use in our households is about 98 gallons a day, says a U.S. Geological Survey. The industrial goods we use -- paper, cotton, clothes -- that's about another 44 gallons a day. But it takes more than 1,000 gallons of water a day per person to produce the food (and drinks) in the average U.S. diet, according to several sources. More than 53 gallons of water go into making 1 cup of orange juice, for example.
Just to get a sense of how much water goes into growing and processing what we eat, here's a list of the water footprint for some common foods, via National Geographic:
A 1/3-pound burger requires 660 gallons of water. Most of this water is for producing beef (see below).
1 pound of beef requires 1,799 gallons of water, which includes irrigation of the grains and grasses in feed, plus water for drinking and processing.
1 slice of bread requires 11 gallons of water. Most of this water is for producing wheat (see below).
1 pound of wheat requires 132 gallons of water.
1 gallon of beer requires 68 gallons of water, or 19.8 gallons of water for 1 cup. Most of that water is for growing barley (see below).
1 pound of barley requires 198 gallons of water.
1 gallon of wine requires 1,008 gallons of water (mostly for growing the grapes), or 63.4 gallons of water for 1 cup.
1 apple requires 18 gallons of water. It takes 59.4 gallons of water to produce 1 cup of apple juice.
1 orange requires 13 gallons of water. It takes 53.1 gallons of water for 1 cup of orange juice.
1 pound of chicken requires 468 gallons of water.
1 pound of pork requires 576 gallons of water.
1 pound of sheep requires 731 gallons of water.
1 pound of goat requires 127 gallons of water.
1 pound of rice requires 449 gallons of water.
1 pound of corn requires 108 gallons of water.
1 pound of soybeans requires 216 gallons of water.
1 pound of potatoes requires 119 gallons of water.
1 egg requires 53 gallons of water.
1 gallon of milk requires 880 gallons of water, or 54.9 gallons of water for 1 cup. That includes water for raising and grazing cattle, and bottling and processing.
1 pound of cheese requires 600 gallons of water. On average it requires 1.2 gallons of milk to make 1 pound of cheese.
1 pound of chocolate requires 3,170 gallons of water.
1 pound of refined sugar requires 198 gallons of water.
1 gallon of tea requires 128 gallons of water, or 7.9 gallons of water for 1 cup.
1 gallon of coffee requires 880 gallons of water, or 37 gallons of water for 1 cup. "If everyone in the world drank a cup of coffee each morning, it would 'cost' about 32 trillion gallons of water a year," National Geographic notes.
Source: Betty Hallock
http://www.latimes.com/food/dailydish/la-dd-gallons-of-water-to-make-a-burger-20140124-story.html