Chemical quality of groundwater

For groundwater, quality can be influenced both by the presence of pollutants resulting from anthropogenic pressures and by the presence of substances of natural origin (e.g. ammonium ion, iron, manganese, arsenic) that may compromise the valuable uses of the water resource. Exceeding quality standards (defined at European level) or threshold values (defined at national level) leads to the attribution of a poor chemical status of the monitoring point. This indicator differs from the chemical status, which according to the legislation should take into account only the anthropogenic component of unwanted substances. Water quality is classified as good if all substances are present in concentrations below the numerical standards laid down in Legislative Decree 30/2009.