Linking Danish agricultural nitrogen fertilizer regulation to nitrate levels in drinking water

Denmark depends fully on simple treated groundwater for drinking water. The nitrate levels in groundwater increased in the 1970s and 1980s from high use of artificial nitrogen fertilizers. In the mid-1980s, Denmark regulated agricultural nitrate-application and stopped this trend. The presentation will focus on how national mitigation measures have successfully lowered nitrate pollution in ground- and drinking water by linking nitrogen surplus in agriculture to age-dated groundwater sample. The presentation will also discuss how recent more-targeted regulation, using a newly developed concept, is needed to lower the impact further to meet the current legislative demands.