Surface water pollution caused a growing concern for environmental damages (algine bloom, waterlife reduction, etc.) mostly for some aspects connected to public health (through the food chain or directly to water management), to crops and to soils (loss of fertility and foodstuff production capacity) especially given by the accumulation of toxic substances. In 1991 the Veneto Region Land Reclamation Union began to cooperate with ESAV in order to carry out an investigation on water quality conditions to optimize its use and to prevent pollution. The results emerging from this enquiry are taken into consideration in this study-case, as regards the main soluble nitrogen (nitrates) and phosphorus (ortophosphates) forms to know the level of nitrogen and phosphorus enrichment risk of surface water in Veneto Region.