Anomalously high nitrate concentrations in ground water

Anomalously high nitrate concentrations are found in aquifers with agricultural lands in their recharge area, with restricted water outflows and with partially penetrating wells which induce ground water recirculation. A comprehensive methodology is proposed, which characterizes the source term -- nitrate leaching -- in time and space and couples it to the hydrodynamic characterization of the aquifer. The methodology is applied to a heavily polluted aquifer. Results show that poor management of irrigation and fertilization practices cannot be separated from unfavorable hydrodynamic conditions to explain concentrations as high as 160 mg/L NO3--N in ground water.