GE 5: Enabling farmers to better protect the groundwater from nitrate and veterinary pharmaceuticals
Responsible beneficiary: OOWV
The aim of this pilot is to strengthen the Precautionary Drinking Water Protection at farm level.
Large parts of the provision area of OOWV are characterized by intensive agricultural land use combined with little buffering soil conditions, i.e. with vulnerable underlying groundwater bodies. OOWV as the largest water provider in this area, works closely with local farmers in drinking water cooperations to support groundwater protection. However, the development of groundwater quality (e.g. re-increasing nitrate concentrations) shows that this is not sufficient. Pollutants (e.g. nitrates or veterinary pharmaceuticals) on their way to groundwater layers are a constant threat for drinking water: if they reach the water procurement areas (i.e. the deeper groundwater layers), it will be rather impossible for water providers to remove them again. This is a shared challenge in many regions of NSR. Therefore, the design of the method, in particular concerning sampling and analyzing the relevant soil layers, will be in close cooperation with the other pilots (e.g. BE_2, DK_3, DK_5).
Farmers want and need to better understand how vulnerable the soil is with in regard to different pollutants, and how their soil management practices can be changed to better protecting the groundwater while at the same time optimizing their economic yield. Different measures (e.g. time / load of N – application, management of catch crop) will be tested and optimized. This is even more important in context of changing climate as topsoil characteristics are changing which are most relevant for the transformation and preferential transport of veterinary pharmaceuticals and of nitrates.
The following activities will be part of the pilot:
• OOWV and LWK will develop a farm based soil map in a participatory process for 3-6 selected farms of different production types in the area of south of Oldenburg.
• BGR will estimate here the input of nitrogen, selected veterinary pharmaceuticals (e.g. sulfonamides) based on application practices of farm fertilizers
• BGR and OOWV will sample/ analyse soil and seepages for analysis selected veterinary pharmaceuticals to estimate the exposure, transformation capacity of the vadose zone at different (extreme) weather conditions and to develop a first proxy for a recommended threshold for such emerging pollutants, as well as to identify high risk areas.
• BGR, OOWV and LWK will test different measures for reducing leaching of nitrates and veterinary pharmaceuticals into groundwater by considering extreme weather conditions.
• BGR and OOWV will test different N-balancing-methods on farm level best corresponding with N-results in soil samples in autumn will be selected.
Stakeholders are Water company, farmers and farmers association, and other water users (municipalities,…)