Diffuse agricultural pollution of groundwater: addressing impacts in Denmark and Eastern England

Diffuse groundwater pollution by agricultural land-use practices is a major international problem. The evolution of the problem in two similar areas of Northern Europe, highly dependent on groundwater for public water supply and arable agriculture for economic production, is reviewed over decades through reference to some exceptionally long-term monitoring data. In Denmark, the greatest concern has been with excessive concentrations of pesticides and their metabolites but significant nitrate problems have also been experienced in some areas. In Eastern England, rising groundwater nitrate concentrations constituted the greater problem but pesticide issues also had to be confronted. An in-depth assessment of the approaches available to water utilities for addressing the problem is provided, contrasting treatment solutions, which have major implications for carbon footprint, with land-use controls, to eliminate or reduce nitrate and pesticide leaching, in groundwater source catchment areas.