In corporation with the Helmholtz Zentrum München a new paper is published in FEMS. This paper is the fourth in a series of planned papers of the Chair of Hydrogeology focusing on nitrate contamination in and nitrate removal from groundwater. To solve this environmental health problem, we started to develop a natural attenuation system to remove excess nitrate from drinking water, where only harmless end-products are formed. In this context the Chair of Hydrogeology at TUM will work on technical solutions and the understanding of biogeochemical processes within the N-cycle to develop a cutting-edge method to remove excess nitrate from drinking water. The new paper focusing on hydrogenotrophic denitrification in groundwater.