Question to the Department for Business, Energy and Industrial Strategy:

To ask the Secretary of State for Business, Energy and Industrial Strategy, what (a) estimate and (b) assessment his department has made of the (i) amount and (ii) composition of materials in the (A) steel jackets and (B) concrete bases underneath decommissioned Brent oilfield platforms (1) Bravo, (2) Charlie and (3) Delta east of Shetland.

The Brent decommissioning proposal conservatively estimates that the cells contained within the concrete gravity based installation contain approximately 640,000 cubic metres (m³) of hydrocarbon contaminated seawater and 40,000 m³ of hydrocarbon contaminated sediments with a total estimated hydrocarbon load of approximately 16,000 tonnes. BEIS officials have reviewed the associated environmental impact assessment including supporting technical documents and have determined that the environmental impact assessment presented by Shell demonstrates that the decommissioning proposals would not have a significant adverse effect on human health, the environment or other users of the sea, and that leaving the cell contents in-situ is the best management solution. The Brent Alpha steel jacket has no materials remaining within it.

Any approval of the derogation permit to leave in-situ the footings of the Brent Alpha steel jacket and the concrete gravity based installations Brent Bravo, Brent Charlie and Brent Delta will include permit conditions to continue to develop technology for the management of the structures (including in-situ remediation for the contents of the structures). Shell and the Brent field licensees will remain responsible and liable in perpetuity for any structures left in-situ.

In addition, drill cuttings piles are present on the seabed at all of the Brent installations and on top of cells of the concrete gravity based installations and BEIS officials have determined that the best management option is to leave the cuttings piles to degrade in-situ.