Nord Stream 2 environmental monitoring results confirm conclusions of EIAs

The report covers results of environmental monitoring of relevant onshore and offshore construction activities such as pipe-lay, dredging/backfilling operations, munitions clearance and rock placement that took place in Russia, Finland, Sweden and Germany in 2018. The construction work in conjunction with the sensitivity of the marine environment governed which of the 26 parameters were monitored in the different countries and when monitoring took place. The monitoring scope and schedule were discussed and agreed with the national authorities. For example, monitoring targeted construction activities that could potentially impact the environment (e.g. munitions clearance in Finland) as well as sensitive/protected areas (e.g. Kurgalsky Nature Reserve). Up to 40 independent contractors have been monitoring the actual impacts on the environment and marine life. This included monitoring of the abiotic environment (e.g. water quality and underwater noise), biotic environment (e.g. benthos and marine mammals) and socio-economic environment (e.g. cultural heritage and ship traffic) before, during and after construction along the pipeline route.

The monitoring results demonstrate that potential impacts were successfully minimised by the planned pipeline routing and adapted construction approach with associated mitigation measures and innovative techniques. For example, to minimise the risk that marine mammals would be exposed temporary or permanent hearing damage or behavioural changes, bubble curtains were used to reduce noise levels during munitions clearance in the Gulf of Finland. Also, microtunnelling and an open-cut construction method relying on trench boxes were used at the landfalls to reduce impacts on the shore ecosystems.

The results of offshore monitoring verified that:

• Due to the use of marine mammal observers, seal scrammers and bubble curtains as mitigation measures for reducing impacts on marine life, the impacts related to underwater noise from munitions clearance were smaller than predicted. No impacts on marine mammals were observed.
• Construction activities have not caused any significant impacts on water quality: monitoring of turbidity and water quality at the locations of all construction activities proved to be in line or below the values predicted in the EIA.
• Impacts on the biotic populations were monitored from plankton and benthic communities to marine mammals. The results show that the impacts were generally temporary and in line with the assessments in the EIAs. The general conditions, for example distribution and structure of the monitored populations remained typical for the Baltic Sea.
• Due to successful mitigation measures, no impacts on ship traffic occurred and third-party shipping traffic did not record any incidents. The mitigation measures included authority notifications prior to the start of any construction activity and regular construction plan up-dates by the construction vessels to the authorities. Furthermore, in Germany, a Marine Coordination Centre was established in coordination with the regional administrative maritime traffic centre to mitigate impacts on third party shipping. The Nord Stream 2 construction fleet was also equipped with GPS transponders for real-time tracking.
• No impacts on protected shipwrecks occurred due to the successful implementation of safety zones around the wrecks during the construction activities.
• All unplanned events were reported to the relevant authorities and additional mitigation measures were deployed to prevent their reoccurrence. For example, in Germany, unexpected release of grease occurred during dredging operations. Dredging was suspended immediately after discovery and beach cleaning was carried out. Beach monitoring continued for four weeks to ensure that consequences of the grease spill were eliminated. Chemical analysis of seabed sediments did not show any residual pollution resulting from spilled grease. Furthermore, the use of biodegradable, environmentally acceptable lubricants was introduced throughout the project.

The results of onshore monitoring verified that:

• In Russia, environmental monitoring at the construction sites and camp confirmed the conclusions of the environmental impact assessment. No significant impacts on the flora and fauna of the protected Kurgalsky reserve have occurred and no significant impacts on birds including the migratory species have been observed.
• In Germany, environmental impacts potentially resulting from beach crossing could be avoided entirely by microtunnelling. Construction activities were conducted in line with permit conditions and planned mitigation measures. No significant change in ground water level resulted from tunnelling and pipeline installation works.

Nord Stream 2 is committed to building a safe and sustainable subsea pipeline system that causes no significant or lasting impacts on the Baltic Sea, the onshore environment or local communities. The purpose of environmental monitoring is to verify the actual impacts of construction activities. It also confirms fulfilment of the permit requirements and commitments made in the five countries through whose waters the pipeline is built (Russia, Finland, Sweden, Denmark and Germany), and monitors the recovery of the environment after construction. The monitoring reports are prepared by independent environmental consultants and regularly submitted to the relevant authorities.

By the end of 2020, Nord Stream 2 will have invested over €100 million in environmental surveys, assessments, analyses, monitoring and conservation activities. Monitoring will continue for several years during the operations phase.

Read the article online at: https://www.worldpipelines.com/project-news/06022020/nord-stream-2-environmental-monitoring-results-confirm-conclusions-of-eias/