Don Field Decommissioning Programme (pdf, 7.8MB) null - BP

Don Field Decommissioning ProgrammeDON-BP-001Although shipping emissions are not formally reported as part of UK submissions to theEU, the estimates of shipping emissions are included as a memo item in the nationalgreenhouse gas inventory. Table 9.1 outlines the CO 2emissions associated with the Dondecommissioning programme relative to the total UK offshore emissions.UK Offshore CO 2Emissions(tonnes)Don Decommissioning CO 2Emissions(tonnes)25,333,624 14,281 (0.053%)Table 9.1 Don Decommissioning CO 2Emissions Relative to Total UK Offshore CO 2EmissionsBased on 2006 UK data, the total emissions associated with decommissioning the DonField facilities contribute to 0.053% of total UK offshore emissions and are therefore notconsidered significant in either local or global terms.7 Seabed Disturbance7.1 IntroductionDuring the removal of the Don facilities, a large amount of work is required to be carriedout at or near the seabed. Therefore, due to cutting operations, lifting operations anddiver support, there is a potential of localised seabed disturbance.7.2 Seabed DisturbanceCutting operations will require the presence of either divers and/or Remotely OperatedVehicles (ROVs) near or at the seabed level. This will increase sediment movement andwater column turbidity and subsequent re-deposition of fine/light sediment, although thiseffect will be short-term and localised.Lifting objects from the seabed will disturb the surface layer of the sediment. It will alsoincrease the turbidity, and to a lesser extent the mixing of the water column.In addition, disturbance to the cuttings accumulation may disturb the contaminants(including heavy metals) within it and this could lead to resuspension and release ofthese contaminants into the surrounding water. This creates the possibility ofcontaminants entering the marine food chain. However, due to the small size of thecuttings accumulation, there is not expected to be any long-term impacts.It is expected that although the effects of the seabed and any cuttings accumulationdisturbance would be undesirable, these are likely to be minor impacts that would beshort-lived and localised. In addition, impacts on benthic biota living in the Don Field areunlikely to be significant or long lasting.Environmental Impact AssessmentMay 2011 9-5