Evaluation of Nitrogen Non-Point Sources in Po River Near Turin

The non-point hydraulic and nitrogen loads in the stretch of Po river upstream and downstream from the city of Turin have been investigated, on the basis of regular data concerning quality and flow rates in the river in different periods of a reference year. The collected data have been organized in terms of hydraulic and mass balances, taking into account input points, affluents and withdrawals, and the missing terms as concern non-point loads or transfer phenomena with surrounding banks and connected aquifers have been identified.From the nitrogen speciation it was possible to distinguish between different contributions to river load, and to estimate presence of agricultural loads, run-off phenomena from impervious urban areas, aquifer connections. All these information can be useful for a better assessment of the surrounding territory in order to improve river quality for different uses.