Isotopes for improved management of nitrate pollution in aqueous resources: review of surface water field studies.

Background: Environmental agencies have to take measures to either reduce discharges and emissions of nitrate or to remediate nitrate-polluted water bodies where the nitrate concentrations exceed threshold values. Isotope data can support the identification of nitrate pollution sources and natural attenuation processes of nitrate.

Review: This review article gives an overview of the information available to date regarding nitrate source apportionment in surface waters with the ambition to help improving future studies.

Present limitations and future prospects of stable isotope methods for nitrate source identification in surface- and groundwater.

Nitrate (NO3(-)) contamination of surface- and groundwater is an environmental problem in many regions of the world with intensive agriculture and high population densities. Knowledge of the sources of NO3(-) contamination in water is important for better management of water quality. Stable nitrogen (delta15N) and oxygen (delta18O) isotope data of NO3(-) have been frequently used to identify NO3(-) sources in water.