I believe water quality describes the condition of water, including chemical, physical and biological characteristics, normally with respect to its suitability for a particular purpose such as drinking or swimming. It is the measure of the condition of water relative to the requirements of one or more living species and to human need or purpose. An example of water quality assessment is determining the concentrations of organic and inorganic chemicals, such as nutrients, trace metals and dissolved organic matter; additional chemical parameters indicative of habitat suitability, such as pH and dissolved oxygen; and physical parameters, including water temperature and turbidity.