In large parts of Europe and North America, the decline in industrial emissions over the past 20 years has reduced pollution of the atmosphere and in turn of soils and water in many natural areas. The fact that this positive development can also have negative implications for these regions has been demonstrated by scientists at the Helmholtz Centre for Environmental Research (UFZ) in the journal Global Change Biology. According to their findings, declining nitrate concentrations in the riparian soils surrounding the tributary streams of reservoirs are responsible for the increasing release of dissolved organic carbon (DOC) and phosphate and a deterioration in water quality. In the case of drinking water reservoirs this can cause considerable problems with respect to water treatment.