WFD - Annex V - 2.4.1. Groundwater monitoring network
The groundwater monitoring network shall be established in accordance with the requirements of Articles 7 and 8. The monitoring network shall be designed so as to provide a coherent and comprehensive overview of groundwater chemical status within each river basin and to detect the presence of long-term anthropogenically induced upward trends in pollutants.
(see Annex V 2.4.1. Groundwater monitoring network - L327/62)