• LinkedIn
  • Twitter
  • Youtube

Research for the UK Environment Agency into three Groundwater Dependent Terrestrial Ecosystems

Our experts carried out a study to find out the risk of pollution at three Welsh Groundwater Dependent Terrestrial Ecosystems.


Groundwater Dependent Terrestrial Ecosystems (GWDTEs) form key environments that are designated protected areas under the Water Framework Directive (WFD). The groundwater bodies that look after such areas are subject to assessments evaluating whether they support or actually threaten the site conditions.

Typical examples include wetland ecosystems where groundwater reaches the earth’s surface and the water emerging in the form of springs or seeps may have experienced contrasting residence times. These can range from weeks to thousands of years and the groundwater pathways vary from deep; short to long; and through a variety of host rocks. The springs and seeps serving GWDTEs can contain high levels of nutrients impacting wetland biodiversity and overall site condition.

We were tasked by the UK Environment Agency to investigate the risk of pollution to wetland vegetation regimes at three GWDTEs in Wales. Our team analysed water quality at two calcareous fen sites in Anglesey- Cors Bodeilio and Cors Erddreiniog and a humid dune slack site in S.W Wales- Merthyr Mawr.

Our research showed how important it is to consider both nitrate pollution and phosphorous inputs in order to understand damage related to nutrient enrichment- with the Merthyr Mawr site revealing the most prominent effects. Although our study has enabled a better understanding around the risk of nitrate pollution to GWDTEs, a significant challenge to address the problem remains. Nitrates often arise in groundwater from widely spread sources, such as farm fertilisers which may have been applied decades ago, meaning actions taken now may similarly take decades to provide benefits. For now our experts suggest voluntary actions via partnerships and uptake of good farming practices to be the best solution to improve conditions at these sites.



Angelo Papaioannou
Angelo Papaioannou Principal Engineer