The challenges of agricultural diffuse pollution
ABSTRACT: Agricultural diffuse pollution is of concern in Spain, as it is in most European countries. The mountainous nature of the Iberian Peninsula and the Spanish islands explain the coexistence of areas little affected by nitrate with others in which this pollution is intense, especially where there is intensive cropping and livestock production, mostly pig farms. The use of chemicals in agriculture and intensive livestock production do not differ from other European countries, although the different climate and soil conditions explain differences in fertilizers and pesticides application rate and chemicals used. The enforcement of different European Directives poses specific technical and also administrative coordination problems due to the different authorities responsible for water resources and the environment at national and regional level. Many aquifers and the related springs and surface watercourses will not reach the good quantitative and chemical status by 2015 required by the European Water Framework Directive. This means that new terms have to be negotiated, with action that needs to be well defined in technical, economic, social and administrative terms. Most of the work carried out concerns nitrate pollution, vulnerable zones and good agricultural practices, but there is also saline pollution due to the evapoconcentration effect when irrigation water has originally high solute contents, something that is not rare in Spain. Pesticides and emergent pollutants in groundwater and the related surface water are being studied, but results are still in the early stages; their presence may become a serious future challenge for water supply and care of the environment.