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10th November 2015
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10th November 2015

Consultation closes on Irish Offshore Strategic Environmental Assessment 5

An overview of the potential impacts exploration and production activity could have on the Irish environment and appropriate mitigation and monitoring processes.


Public consultation recently closed (17 June 2015) on DCENR’s latest Offshore Strategic Environmental Assessment (IOSEA 5), a major piece of environmental analysis required under European Union law in the context of Ireland’s plans for issuing offshore oil and gas exploration and production authorisations in its national waters. Essentially the requirement is to make a detailed assessment of all of the impacts future E&P activity could have on the Irish marine environment and then set out the mitigation measures and monitoring process proposed to address those impacts.


IOSEA 5 is the fifth offshore Strategic Environmental Assessment (SEA) of a series and studies all of the geographical areas covered by the previous* 4 SEAs plus the entire Goban Spur basins further south. The study area lies within Ireland’s designated Continental Shelf and in parts extends southwards and westwards to Ireland’s 200 mile limit. The documents put out to consultation included not only the draft Environment Plan but also an Appropriate Assessment scoping paper which addresses impacts on marine habitats.


In commissioning the work from UK environmental consultants, ENVIRON, the government’s twofold objectives were:

   To inform DCENR of ‘specific environmental considerations’ in its future petroleum activities under licensing rounds in the Atlantic margin basins and licensing in the Celtic and Irish Seas, and;

   To provide exploration companies working offshore with an operational baseline against which they could conduct their work while ensuring the protection of the marine environment.


Report methodology

The approach taken by the study was firstly to establish and describe the baseline environmental conditions in the study area and then project future expected natural changes caused by, for example, climate change or anthropogenic pressures. The next stage was to examine the predicted effects of exploration activity under two broad headings – seismic activities and drilling activities including accidental events. This was then followed by the detailed actions of the proposed mitigation and draft monitoring plan.



Predicted effects from seismic activities

‘Seismic activities’ include all operations associated with surveying and data-gathering both on board vessels and directly on the sea-bed. The scoping process concluded that there were no likely significant impacts from seismic activities in relation to geology or ocean circulation. However there were a number of other impacts which were considered significant enough to cause concern about moderate or major effects including:

   Noise generation from 2D/3D seismic operations (e.g. airguns, helicopter transfer);

   Physical presence of survey vessels and equipment (including exclusion zones and lights);

   Accidental events (e.g. loss of cable oil, diesel, equipment, dumping, ship collision);

   Seabed damage done by sea node/sea bottom cable surveys;

   Vessel discharges and wastes.


Predicted effects from drilling activities

From the outset given their very nature the drilling activities have a more significant marine environmental impact than the seismic activity. The main impacts identified by the SEA were:

   Physical presence of vessels and rig;

   Presence of subsea equipment;

   Atmospheric emissions from energy generation;

   Potential discharges from normal vessel operations;

   Potential discharges from commissioning of drilling rigs;

   Mud, cement and cuttings release from tophole sections;

   Well-testing (flaring and burner spraying for cooling);

   actual drilling on the seabed;

   accidental events, loss of diesel, chemicals or worst case scenario, well blowout.


Proposed mitigation and monitoring

The SEA proposes a wide range of additional mitigation measures beyond best industry practice. As a result, it is considered that following measures such as habitat studies before deployment of equipment on the seafloor; better coordination and timing of survey work; noise minimisation and minimal discharge of pressure waves; – the purely seismic activity can generally be carried out without significant adverse impacts.

The same cannot be said for the drilling activity and the possibility of accidental effects. Even with the significant additional mitigation measures proposed in the SEA there is still a risk of serious adverse effects in relation to drilling, although the worst possibilities would for the most part be the result of accidents. The main significant impacts identified are:

   landscape, seascape – loss of visual amenity where rigs are within 25Km of national parks, settlements, tourism locations etc;

   Vessel collision damage to water quality and impact on marine wildlife;

   A major well blowout or pipeline leak which could result in major damage to fish, birds, plankton, marine mammals, and at the same time do considerable economic damage to sea fisheries, mariculture and recreational and tourism activities.


Overall, the SEA recognises that not every significant effect can be fully mitigated as there is always the possibility of an accident or, even with the application of best industry practice, something unexpected just going wrong. The SEA therefore proposes to address the possible ‘significant’ effects through intensive monitoring activity.


This includes monitoring of water quality; recording of data on the abundance of fish and other marine life and close consultation with all industries and stakeholders who themselves monitor the marine environment.


Next steps

As the IOSEA 5 is intended to assess any impacts on the marine environment associated with activities conducted under future petroleum exploration and production authorisations in the IOSEA 5 study area, it is therefore a process that needs to be completed by mid-September 2015 when the upcoming Atlantic Margin licensing round reaches its conclusion. This means that DCENR is on a challenging timetable to consider all the responses and viewpoints encountered during the consultation phase, and incorporate them as appropriate in a revised draft before publishing the final SEA Report.


However, the main concern for Government is not that everyone should approve of the final report when published, but rather that the IOSEA 5 process, once concluded, will be accepted as having been carried out properly and in accordance with Ireland’s legal obligations.


Thereafter, the main stakeholder focus will be on the outcome of the Atlantic Margin Round itself.