Water is a necessity for the survival of humans, which is why a central challenge for the 21st Century is providing sufficient clean water for a growing world population. Access to clean water was even defined by the United Nations as a human right in 2010: Every person has the right to clean water for drinking and personal hygiene. Fresh water is also essential for the production of industrial and agricultural products.
Seventy percent of the water resources used worldwide is used by agriculture - the majority being for irrigation and the production of food. Twenty percent is used by industry, and ten percent is used in the household area. In addition to its enormous consumption of water, industry and agricultural production processes also contribute to water pollution.