Dinámica de la contaminación por nitrato en el sistema acuífero de la Plana de Vic (Osona, Barcelona) = Nitrate pollution processes in the Plana de Vic aquifers (Osona, Barcelona)

Abstract

Nitrate pollution in the Plana de Vic aquifers has presently reached very high levels, which pose enormous limitations to its use. The origin of nitrate is mainly caused by manure application as fer tilizer. In this paper, we present a hydrodynamic scheme of the Plana de Vic aquifer system, based on potentiometric data and nitrate concentrations obtained through a monthly monitoring effort of a 80 well database. The response of those wells to the recharge that ended a severe drought period allows us to depict different hydrogeological behaviours between surface and deep aquifer levels. We conclude that a mixing process occurs in this multilevel leaky-aquifer system facilitated by the uncasing of most of the wells. Therefore, a deficient exploitation of the aquifer is seen as an additional cause for the spreading of nitrate