Determination of background concentrations of hydrochemical parameters and water quality assessment in the Akhuryan River Basin (Armenia)

•Calculation of background concentrations for Akhuryan River Basin.•Derivation of site-specific assessment system for Akhuryan River Basin.•Assessment of surface water quality in Akhuryan River Basin by chemical status.

The determination of background values of hydrochemical parameters, to distinguish between natural concentration and anthropogenically-influenced concentrations, is highly relevant. In presented study, to estimate the background values of hydrochemical parameters in Akhuryan River Basin, log-normal probability functions on the hydrochemical parameters concentrations was applied. The study is carried out on the basis of hydrochemical data of surface water quality monitoring for the period of 2010–2013. This study highlights the usefulness of application of site-specific background concentrations for the evaluation, interpretation of surface water quality and for determination of pollution sources.