Potable water, water fit for drinking, must be free of pathogens, toxic chemicals, and excessive or harmful concentrations of dissolved salts. Pathogens, especially fecal-oral pathogens, should be detected by routine tests that are best conducted by professionally qualified staff in an authorized laboratory. Public health and environment departments often work in collaboration to monitor and maintain surveillance of drinking water quality. When budget cuts force reductions in rigorous surveillance, outbreaks of water-borne diseases almost invariably occur. Irrigation water may contain some pathogens, and its chemical content should not cause buildup of harmful salts in the soil. Industrial water is often heated and cooled again, so it must be free of dissolved salts that could crystallize out. The criteria applicable in the United States are available at http://www.epa.gov/waterscience/standards/. Those in other countries are similar.
Subjects: Public Health and Epidemiology.