This summer, the research team from Gdańsk University of Technology conducted an intensive field campaign in the Puck use-case to better understand how agricultural contaminants (nitrogen and phosphorus) move through soil and groundwater. The work was carried out in close collaboration with the Polish Geological Institute – National Research Institute.

Since June, the team has been collecting water and soil samples every 1-3 months at three locations in the study area. The aim is to monitor changes in agricultural contamination over time and across different areas.

Samples were taken from subsurface environmental compartments particularly affected by contaminants:

• shallow groundwater
• soil in the vadose zone at three depths.

Laboratory analyses focused on biogenic compounds such as:

• Nitrate, nitrite, and ammoniacal nitrogen
• Total nitrogen
• Total phosphorus and orthophosphates.

These measurements were performed using a spectrophotometric method with Hach cuvette tests, assisted by specialised equipment for sample digestion and result reading.

To estimate permeability of the vadose zone, which is an important factor influencing contamination movement down from the ground surface, the researchers also took samples of undisturbed shallow soil (up to 1 m deep). These samples, mainly consisting of sand with local additions of peat, will be tested in sand and sand-kaolinite apparatus to determine their hydraulic properties (in particular, retention curves). The varying presence of organic matter in the unsaturated zone material makes permeability estimation more difficult, and requires further investigations.

By combining field measurements with modeling, the research will contribute to smarter management of agricultural impacts on water resources in the region.