WFD Cycle 2 River ANC Classification

This dataset is a subset of the "WFD Classification Status Cycle 2" product. It contains summary data for the element acid neutralising capacity (ANC) for river water bodies, as used in the classification for Ecological status for the water framework directive (WFD). The ANC classification dataset is an element of the physico-chemical group or element set and is used to consider particular phyisco-chemical conditions. While pH can be considered as a measure of acidity, ANC is a direct measure of anthropogenic acidification and is commonly used for managing acidification at a national level. It is a calculated measurement based on pH, dissolved organic carbon and alkalinity data. The measurement results for a site are calculated into a annual mean concentration and assessed against two sets of environmental quality standards (EQS), which are derived from a site’s typology. Site classifications for ANC use categories of High, Good, Moderate, Poor, and Bad.