Implementation of projects to create support zones is closely linked to the optimization of the system of state control over the environmental situation in the Russian Arctic. Previous studies have shown that zones of ecological disadvantage, as well as impact areas, have formed on these territories. In this regard, the urgency of developing and adapting scientific methods for monitoring the status and methods of regulating the quality of freshwater ecosystems is growing. Recent studies show that the reasons for changing the quality of freshwater ecosystems are the introduction of the substances with anthropogenic origin into the water mass and the modification of chemical components of the natural water environment, changes in its physical characteristics and other properties of the freshwater ecosystem.

The aim of this work is to assess the hydrological and environmental state of the river ecosystems in the support zones of the Russian Arctic. The analysis of the long-term regime hydrochemical information (1990–2010) of the state observation network of the Roshydromet was carried out using methods of complex indicators calculating and risk of anthropogenic impact assessments.

Variability of the water pollution degreeis analyzed. Priority and critical hydrochemical indicators are identified. It is shown that the role of the anthropogenic component is currently determinative in the transformation of their hydrochemical regime for the river ecosystems of the support zones under study. Their hydrochemical regime is characterized by high spatial, interannual and intra-annual variability of the component composition of the aquatic environment; formation of a higher “anthropogenically-altered natural background”; periodic accumulation in the water environment of priority pollutants to concentrations of tens of hundreds of times the maximum permissible concentrations, an increase in the frequency of cases of high and extreme high pollution.