The objective of WP4 is data collection and to establish links between nitrate dissipation and geophysical, geochemical, and hydrological characteristics of the aquifer system to be used as input to upscale modeling in WP5.

This includes:

• Establishment of 2 pilot areas
• Geophysical mapping of geology and tile drains
• Hydrological, hydrogeological, and hydrochemical characterization, measurements in the saturated zone, and hydrological measurements in streams
• Geochemical measurements of nitrate dissipation rates, and characterization of nitrate reduction capacity in the subsurface
• Geochemical characterization of the redox conditions and nitrate interfaces
• Citizen‐monitoring involvement with respect to e.g. drains, wells, and surface water.