Chemicals in European surface water and groundwater (Signal)

Chemicals in European surface and groundwater bodies are monitored under the . This includes chemical status assessments, reported by EU Member States under their River Basin Management Plans (RBMPs) since 2010. In surface waters, detected chemicals are assessed against a list of . Concentrations are compared to . 

In groundwater, EU standards for nitrates and pesticides are determined by the , while national thresholds are used for other pollutants.   

The third River Basin Management Plans (RBMP) in 2022 showed that only 30% of surface water bodies in the EU-27 have good chemical status. This is primarily due to a small number of ubiquitous, persistent, bioaccumulative and toxic substances such as mercury and brominated flame retardants. ​However, their persistent properties mean that they will remain in the environment for a long time even after they are no longer released. If excluded from the analysis, 78% of surface water bodies would achieve good chemical status. Meanwhile, around 22% of the area of groundwater in the EU-27 failed to achieve good chemical status. In the EU, .  

The provisionally agreed revision to the Environmental Quality Standards Directive and the Groundwater Directive introduces new substances into the priority lists, including pesticides, pharmaceuticals, bisphenols, and per- and polyfluoroalkyl substances (PFAS). Trifluoroacetic acid (TFA), a breakdown product of certain PFAS, is included in the sum of 25 PFAS for surface water. A sum standard of pesticides for surface waters is also introduced and set at 0.2 µg/l, covering substances already listed as priority substances. Bisphenol-A is designated as a priority hazardous .    

River basin-specific pollutants (RBSPs) – substances discharged in significant quantities into a river basin – are . In the third RBMP, these contributed to the assessment of ecological status of surface water bodies, with classifications ranging from ‘bad’ to ‘high’. The two RBSPs most frequently reported as failing EQSs across Member States in the third RBMPs were zinc and arsenic (over 1000 surface water bodies failing out of c.92,000). Other monitored substances in specific river basins include pesticides, such as aminomethylphosphonic acid (AMPA) and diflufenican.     

It is important to note that status assessments are based on individual substances, which can overlook potential risks from chemical mixtures.   

The revised . It includes steps to tackle micropollutants and microplastics in wastewater treatment by requiring the monitoring of micropollutant removal, reducing releases of untreated sewage during periods of intense rainfall and tracking the source of . These measures would help reduce the occurrence of substances of concern in effluent from wastewater treatment plants and their upstream introduction into surface water bodies. They would also support the transition to the production of safer and more sustainable chemicals. 

Please consult the relevant indicators and signals below for a more comprehensive overview on the topic.