Nord Stream conducts an extensive environmental and socio-economic monitoring programme to determine any impact of the construction and operation of the pipelines. The 2011 annual report, the second of five such reports planned, has now been published. The report summarises the national reports for Russia, Finland, Sweden, Denmark and Germany respectively.
All the results are publicly available and have been reported to the relevant national authorities. On Nord Stream’s own initiative, these results are also shared with all the nine Baltic Sea countries which took part in the international consultations before the start of the pipeline project.
In 2011, monitoring of air quality was performed once per month between January and December at seven stations during construction works and installation operations on the shore and in the near-shore area. The monitoring programme for air quality was designed to monitor emissions of pollutants and air quality in the work zone and at the boundary of a residential area.
All measures of nitrogen dioxide, carbon monoxide, particulates and hydrocarbons (in relation to kerosene) sampled at monitoring stations located at the boundary of the construction site, and within the area near the village Bolshoy Bor, were below the maximum allowed concentration. Based on the monitoring results, it was concluded that the air quality in the area of the onshore section of the pipelines was in accordance with the requirements of Russian government health norms.
In 2011, sediment quality was monitored upon the completion of Line 1 construction at two stations in Finland and three stations in Estonia. The results show that the construction of Line 1 did not cause changes to the concentrations of harmful substances of surface sediment in Finnish or Estonian waters. Metal and dioxin concentrations were generally low and TBT concentrations lower than in 2010.
In 2009-2011, monitoring of current speed and direction was carried out at seven stations. Information collected at one station near the installed Line 1 demonstrates that the impact of the pipeline on currents was minor in the direct vicinity of the pipeline and negligible at distances greater than 50 metres (m). Results from six other stations where currents were measured throughout the water column show that the actual current speeds were generally higher than modeled and there were more currents in the north-south direction than modeled. The actual impacts of construction on water quality were, however, in line or less than assessed.
Monitoring of ecotoxicological effects in blue mussels (Mytilus edulis) was conducted at Norra Midsjöbanken, a Natura 2000 area. The results show that sediment spreading from post-lay trenching of the pipeline into the seabed did not lead to an increased content of contaminants in mussel tissue, and it was concluded that mussels were not affected by post-lay trenching activity in the area.
In addition, the monitoring results demonstrate that the sediment and the benthic fauna has not been affected by post-lay trenching, anchor handling or the laying of Line 1 at the monitoring stations in 2011. The recorded temporal changes since 2010 and the spatial differences in 2011 were identified as results of natural changes in the composition and structure of the benthic community.
In Danish waters, safety zone restrictions were initially established around 27 cultural heritage locations on the seabed. The monitoring programme for Denmark included monitoring of two locations, i.e. the two wrecks which were situated closest to the pipelines. Underwater footage of the wrecks was recorded in autumn/winter 2010/2011 and the results of the surveys showed that there was no damage to or disturbance of either of the two wrecks during the construction activities for Line 1.
In July 2011, prior to installation of Line 2, a survey of protected wreck sites identified in Danish waters was conducted. As a result of the investigations, out of the original 27 exclusion zones, only 17 had to be upheld during construction of Line 2, and some of the remaining exclusion zones could be reduced from a 200 m radius to a 100 m radius.
A so called offset measure has been implemented at the German landfall. The goal is to develop coastal sandy and neglected grasslands as a compensation for the disturbance of protected biotopes in the landward landfall corridor of the Nord Stream pipelines. Dune reinstatement/development was carried out successfully in 2010 and 2011, including construction of an artificial dune on top of the pipelines, as well as partial sand exchange around the project area.
No concentrations of contaminants throughout the sampling periods (the baseline investigation and the post-construction investigation) exceeded the relevant threshold value of the German dredging/dumping regulations.
Press Release, September 24, 2012