Alternative routes of the Russian section of the Nord Stream 2 gas pipeline were studied using environmental criteria. The planned anthropogenic impact was assessed making use of a complex of biotic and abiotic parameters of marine ecosystems allocated in the zones of influence. On land the water protection zones and coastal protective strips of water bodies, specifically protected natural areas, cultural heritage sites, settlements' infrastructure and land transport routes were allocated. The offshore zone of the pipeline includes the navigable routes, anchorages, areas of dangerous navigation and limited access due to the Navy activities, areas of intersection with the existing marine infrastructure (cables and pipelines), fishing areas, areas of dangerous exogenous geological processes and hydrological phenomena (degassing of gas-saturated deposits, ice plowing of the bottom, erosion activity of bottom currents, slope and coastal processes). The results of environmental risk assessment for alternative versions of the Nord Stream 2 route (Russian section) in standard mode and in case of potential accidents are presented.