Background Crop protection products (CPP or pesticides) can pose significant risks to the environment or to human health. In France, 90% of the surface water samples analysed in 2000 for regulatory monitoring showed the presence of pesticides. A total of 320 different substances were detected. The runoff of pesticides from agricultural land during rainfall events is one of the major causes of the pollution of surface waters. Objectives The main objective of the SWAP-CPP project was to demonstrate the possibility of protecting surface waters against crop protection products run-off from arable lands by means of cost-effective agricultural practices. Specific objectives of the project included: Quantify CPP runoff in two worst case situations (wine production in Champagne, France, and potato growing in Wallonia, Belgium). Evaluate the costs and environmental benefits. Provide a communication tool for describing the performance of surface water protection at the level of a homogeneous watershed: the impact index. Promote the dialogue between the worlds of water and of agriculture: water authorities, farmers, technical farmer associations, environmental and farming research, CPP production and distribution industry. Results Emission of pesticides to the surface water The SWAP-CPP project demonstrated that "zero runoff of pesticides" to surface water is possible in both experimental areas: wine culture in Baslieux-sous-Châtillon, Champagne, France, and potato culture in Gembloux, Belgium. Two small catchment areas were monitored in the wine culture area of Baslieux-sous-Châtillon, Champagne (F) from 2005 to 2007. The quality of runoff was monitored at two different levels (plot and storm basins). Laboratory analyses of 49 main CPP in the water and sediment samples provided 21 000 results. These results show that soil coverage with grass or with crushed barks reduces CPP emissions by 80%. The "zero runoff of pesticides" can be obtained by retention of runoff flow in a basin large enough to hold the runoff of a yearly rainfall event. This last approach crates artificial biologically active wetlands and is applicable to any agricultural catchment. The effects of agricultural practices of the CPP emission from potato culture were evaluated in 2006 and 2007 in Gembloux, Wallonia (B). The analyses of the water samples for 6 pesticides provided 1 000 results. The balking of the furrows in combination with a 12 m long grass strip downstream avoids any emission of pesticides towards surface water. Costs and benefits For the wine culture in Champagne, the investment costs of a retention basin for the annual runoff event is about €2 600/ha plus the cost of land. The operation cost for the combination of soil coverage and retention of annual stormwater in basins is estimated from €35 to 130/(ha.year). For the potato growing, the balking of furrows and the setting up of grass strip were estimated at €90/(ha.year). The total internal and external costs have been evaluated for the various stakeholders: farmers, natural environment, consumers of drinking water (costs calculated by the assumption that 10 % of the emitted water has to be treated to become potable), public authorities (subsidies or penalties for unfulfilled good state). Based on this approach, it is concluded that the costs of prevention as they have been given above are lower than the costs incurred if no actions are being taken. The project demonstrated that the measures are cost-effective and easy to implement. Modelling The emissions of pesticides in wine areas are NOT correlated with their molecular physicochemical properties. Within the project, collaboration with the INRA has allowed a validation of the indicator of risk of transfer of pesticides toward the surface water I-Phy of INDIGO®. In 77% of the cases, a correct prediction is obtained./p> For the potato application, some simple models provided data not very precise but coherent in the order of magnitude, and thus usable as an indication. Many deliverables of the project are available for download on the website, namely the evaluation of cost-benefit ratio, water management and land risk in Europe, and the methods used in the SWAP-CPP project (guidelines). Further information on the project can be found in the project's layman report and After-LIFE Communication Plan (see "Read more" section).