Sub-Group 1: Groundwater

Prioritisation of Contaminants of Emerging Concern in Groundwater

Focus Sub-Group 1: GW

Recital (4) of the Groundwater Directive (GWD) 2014/80/EU requires Member States to identify other substances (besides nitrogen and phosphorus) that “pose a potential risk to groundwater bodies”. An initiative at the level of the European Working Group C “Groundwater” (EU WG-C) has recently been launched to establish a Watch List for pollutants in groundwater, including emerging pollutants.

There are specificities which should be taken into account when prioritising chemical contaminants and in particular contaminants of emerging concern (CECs) in groundwater (GW):

Lack of open-access databases of raw data on CECs in European groundwaters
Long-time transfer of contaminants to the GW (need to provide particular attention to occurrence of substances withdrawn from the market)
Presence of transformation products and metabolites
Impact of diffuse pollution sources
Specific uses of GW with respect to the definition of relevant threshold values
Lack of knowledge of the GW biodiversity (are PNEC relevant for GW?).

A specific GW prioritisation methodology needs to be developed. This task should be dealt with by a specific working group, organised as a sub-group of NORMAN Working Group 1. The GW prioritisation methodology may be addressed to the European Commission as NORMAN recommendation to support the establishment of Groundwater EU Watch List.