The Sea Empress incident: Summary of report

The Sea Empress Incident: Summary of Report

This report describes the MPCUs response to the Sea Empress incident, particularly measures taken to prevent spilled oil impacting the coastline aerial spraying with dispersant and physical recovery of oil at sea and the actions taken to clean the shoreline where oil had reached it. It does not discuss the causes of the accident or the conduct of the salvage operation; these are matters for the Marine Accident Investigation Branch.

At 2007 on 15 February the tanker Sea Empress, laden with approximately 131,000 tonnes of Forties Blend crude oil, ran aground in the harbour entrance at Milford Haven. She was severely damaged and there was an initial loss of crude oil. The Milford Haven Coastguard notified the MPCU at 2027 and the National Contingency Plan was activated. Salvors were appointed by the ship's managers and they chartered a tanker to lighten Sea Empress in situ. However the weather was worsening and it was not possible to bring vessels alongside.

On 17 February tugs were unable to hold Sea Empress against the combination of wind and strong tide and she was swept on to rocks off St Anns Head, suffering further damage and releasing more oil. During the following 3 days more groundings occurred and more oil was spilled. She was successfully refloated on the evening high tide on Wednesday 21 February and moved to a jetty where the remaining crude oil was pumped off. Sea Empress left Milford Haven on 27 March arriving in Belfast Lough on the 29th; she entered dry dock on 2 April. Approximately 58,200 tonnes of crude oil were unloaded at Milford Haven and an estimated 430 tonnes recovered in the Belfast dry dock; so by difference ~72,000 tonnes were spilled.

From 16 February specially equipped aircraft, guided by remote sensing aircraft, sprayed oil at sea with dispersant. No spraying took place after 25 February because any remaining surface oil was in patches too small to treat effectively, or was emulsified and weathered to an extent where it was no longer amenable to the use of dispersants. An estimated 36,000 tonnes of oil were dispersed by aerial spraying or dispersed naturally.

An intensive operation began on 16 February to recover oil at sea, particularly in areas too close to the shore for aerial spraying. Initially 3 vessels were deployed, building up rapidly to over 20 including 2 Dutch and 2 French vessels supplied under the Bonn Agreement for collaboration during oil spills. At-sea recovery continued until 2 March. Recovery in support of beach cleaning continued until 7 March, when work outside the Haven was stopped as it was judged that there was minimal surface oil remaining. In total around 2,000 tonnes were recovered at sea.

With MPCU support a major shoreline clean-up was launched by local authorities which involved over 950 people at its peak. The strategy was to remove bulk oil as rapidly as possible, and delay more meticulous cleaning (polishing) until there was no oil at sea and no chance of significant refloatation from nearby polluted areas. The over-riding priority was to clean amenity beaches to a high standard before the Easter Holidays on 5-8 April. This objective was achieved and effort was then directed to the more technically challenging sites where the main problems were access and the nature of the beach.

The majority of the oil was removed by relatively non-intrusive methods such as low pressure flushing; mechanical scraping with capture by gully suckers; or manual techniques (scrape and shovel, hand wiping). On the amenity beaches dispersants were used to remove weathered oil adhering to rock surfaces. Some shingle beaches were cleaned by moving oiled shingle into the surf zone for natural washing, others by loading oiled material into concrete mixers, washing with water to separate the oil and then returning the clean material to the beach. About 1,500 tonnes of bulk oil were recovered from beaches and other sites.

The report describes a successful counter-pollution operation which at peak activity involved over 1100 people and represented a close collaboration between central government, local authorities, and many other public bodies, private companies and voluntary organisations. Of the 131,000 tonnes of crude oil in the seriously damaged tanker less than 5,000 tonnes came ashore and the main amenity beaches were cleared by Easter. While the national and local contingency plans were successfully activated this report will enable those involved in the Sea Empress incident, and other coastal authorities, to draw out lessons for their future plans.

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