Environmental Science: How to Meet Human Water Needs
Environmental scientists discovered that the second largest consumer of fresh water is you (and every other person in the U.S.). Every day you drink water, brush your teeth, wash your clothes, flush the toilet, and bathe. These types of household or domestic water use account for more than 10 percent of the freshwater use in the U.S. This figure illustrates where the average U.S. household consumes fresh water.
The percentages in the figure are averages for the U.S. The actual use of water in a household depends on what type of plumbing and sewage infrastructure it has. For example, in regions that don’t have indoor plumbing, households don’t use water for flushing toilets.
In addition, the graph doesn’t include outdoor household water use, such as watering the lawn or garden, which accounts for about 25 percent of total household use (on average).
Various industries use water to produce energy, refine metal, and manufacture products. Most of the industrial water use in the U.S. is for the production of electricity, either through hydropower dams or at power plants. Although the capture of energy from moving water, called hydropower, doesn’t consume water because the water is still available for other uses in the ecosystem, other sources of electricity do consume water.
Nuclear reactors and coal power plants, for example, consume fresh water, meaning that the water these industries use for the production of electricity is no longer available for other uses. Both nuclear and coal plants transform water into steam to power engines that generate electricity. In the process, most of the steam is lost to the atmosphere; only some of it is collected, converted back to a liquid, and returned to its source.
Other industrial uses result in water waste, or the pollution of water by metals or chemicals. Mining for ores requires a large amount of water to rinse unwanted minerals away from the desired metal resource. Once mined, these metal resources must be refined and manufactured into products, such as aluminum foil, appliances, and cars. This type of industrial water use is a common source of water pollution.