The latest results from Nord Stream’s environmental monitoring programme in the Swedish Exclusive Economic Zone, EEZ show that the company has complied with and even exceeded the conditions in the permit granted by the Swedish government. Calculations and models in Nord Stream’s Environmental Study have proven accurate, and it is now estimated that the environmental impact so far has been smaller than anticipated.
Lars O Grönstedt, Senior Adviser to Nord Stream:
“We are happy to be able to demonstrate that our Environmental Study, the basis for Nord Stream’s permit application, has been correct and that construction works have had no negative impact on the environment of the Baltic Sea.”
At a seminar in Visby Nord Stream presented three new reports on the company’s environmental monitoring activities. The reports contain results from the measurement of seabed currents and inflow of saltwater to the Baltic Sea; potential turbidity caused by construction works in the vicinity of the Natura 2000 areas at Hoburg’s Bank and Norra Midsjöbanken, as well as the prevalence of contaminants in common mussels.
Measurements of seabed currents and saltwater inflow, so called hydrographical monitoring have taken place in the Bornholm Basin during 2010 – 2011. The pipeline has an average height of 0.7 meter above the seabed in the Swedish EEZ. The purpose has been to verify the assessment that Nord Stream’s pipeline will not cause any blocking of the inflow of saltwater. Two monitoring stations have performed measurements of temperature, salinity and direction and speed of the water currents. Additional measurements have also been carried out from vessels. The surveys have been executed by the Swedish Meteorological and Hydrological Institute, SMHI, on behalf of Nord Stream. The results confirm the previous analysis: Nord Stream’s pipeline will have no negative impact either on the inflow of saltwater or on the water quality of the Baltic Sea.
Monitoring of potential turbidity has been performed in Sweden in areas bordering to the Natura 2000 areas Hoburg’s Bank and Norra Midsjöbanken. The purpose has been to measure turbidity and sediment concentrations during Nord Stream’s trenching activities along certain parts of the pipeline. Four permanent monitoring stations, with direct data transmission were placed at the borders of the Natura 2000 areas and measurements of sediment were also made from vessels close to the trenching vessel. The survey was carried out by Danish DHI and Swedish SMHI on behalf of Nord Stream. Trenching in the Swedish EEZ took place during February – Mach 2011. The measurements show lower levels than estimated in the Environmental Study. The threshold value, 15 mg/l, established by the Swedish government in the permit has never been even close to being exceeded. In fact, average turbidity was below 2mg/l during Nord Stream’s trenching activities.
Eco-toxicological effects on mussels have also been monitored in the Natura 2000 areas south-east of Gotland during 2010 – 2011. The purpose has been to verify that mussels and other living organisms were not affected by potential spreading of sediments and contaminants which could be released due to Nord Stream’s trenching activities. By placing cages with mussels on six different locations (three impact stations and three reference stations) at both offshore banks, samples were collected before, during and after the trenching activities. The collected mussels have been analyzed in order to measure the concentration of metals and tin compounds. The survey was made by Marin Monitoring AB on behalf of Nord Stream. The weighted results from monitoring of eco-toxicological effects on mussels show no measurable impact on the environment of the two Natura 2000 areas Hoburg’s Bank and Norra Midsjöbanken.
[mappress] Source: Nord Stream , July 7, 2011;