Classification and environmental standards - how are they related?

Environmental standards and conditions will describe the physical, chemical and structural characteristics that are required to support biology. These standards will help identify where the water environment may change from being of good quality to moderate quality, or vice versa due to changes in the biology and supporting characteristics. The environment agencies use classification systems to assess the state of the environment at any point in time. They show us where the environment is of good quality and where it may require improvement. Classification systems provide an audit process that enables us to ensure that the measures we take, which are based on the environmental standards, are effective. The Directive sets out how the physical, chemical and structural characteristics will be used in classification. For instance, morphology will be used to assign high status whilst physico-chemical characteristics will support classifying all five classes.

The figure below explains the relationship between the biological quality elements used to classify water and the supporting environmental standards.