Researchers investigated the hidden costs of water use by estimating the amount of H2O consumed per U.S. dollar of end product by different industrial sectors, including agriculture.

For instance, it takes about 270 gallons (1,022 liters) of water to produce a dollar’s worth of sugar, about 200 gallons (757 liters) to make a dollar’s worth of pet food, and 140 gallons (530 liters) to make a dollar’s worth of milk.

Agriculture and power generation—which requires large amounts of water for plant cooling—were the major consumers, accounting for 41 percent of the country’s total water footprint.

Each dollar’s worth of grain production, for example, sucks up 1,400 gallons (5,300 liters) of water.

The study is the first in three decades to examine the U.S. water