The Sea Empress clean-up operations were 'wide ranging and effective' according to a Government report. At sea these included dispersant spraying, mechanical recovery, and the use of protective booms and on shore, mechanical recovery, trenching, beach washing, and the use of dispersants. At the height of the response more than 50 vessels, 19 aircraft and 25 organisations were directly involved with 250 staff working on the response at sea and 950 working on the shoreline. A small shoreline clean-up team was still working 18 months after the spill. The total cost was approximately £23million. Some of the money came from insurance companies but the rest came from the UK government.
The cost of the different options varied widely. For example, it cost:
£60 per tonne of oil for spraying chemical dispersant on the sea surface;
£2,000 per tonne of oil to have it removed from the sea surface by recovery ships;
£9,000 per tonne of oil for the shoreline to be cleaned.

'Mechanical Recovery' - collecting
the oily sand in a bag

'Beach Washing' - spraying
dispersant on to
rocks and sand

'Spraying Dispersant' -
aircraft spraying dispersant at sea

Floating booms were used to protect some sensitive stretches of coast from incoming oil but were only effective in sheltered areas. The clean-up operation on land generated a large amount of waste and its disposal presented a major problem both operationally and legally. Fortunately most was treated at the Texaco land farm but some had to be transported 160 km to a landfill site. Aerial photos, remote sensing and ground surveys were used to locate surface oil. Movements of oil, on the surface and in the seawater, were predicted using a computer model provided with information of wind and current movements. Remote sensing of the oil discharged from the Sea Empress was mainly by aircraft rather than satellite.

446 tonnes of chemical dispersants were sprayed onto the oil from aircraft The dispersants increased the effectiveness of the natural processes by causing the oil to form small droplets and mix into the seawater, substantially decreasing the amount of oil on the surface but increasing concentrations at depth. Oil is a natural product and eventually most of it is broken down by micro-organisms in the water. Around 2% of the oil was collected from the sea surface using recovery vessels and taken to a nearby refinery. Roughly 5,000 tonnes of oil came ashore but this was reduced to about 500 tonnes by late summer as a result of a major shoreline clean-up operation and natural cleaning.

The RSPCA co-ordinated a bird cleaning operation which included many other animal welfare organisations. An emergency centre was set up near Milford Haven at which 3,100 oiled birds of 20 different species were received, most of them between 24 February and 2 March. When fit to travel, birds were taken to local and national cleaning facilities – including the RSPCA wildlife hospital at West Hatch, Somerset where 2,300 birds were treated. Given the enormity of the exercise, the collection of birds, first aid and transportation worked well but at times the large number of birds exceeded the available cleaning capacity. It was not possible, however desirable, to release clean birds near the location where they were collected because of continued oil pollution, and most were released at suitable sites near to the cleaning centres, such as Liverpool Bay. About 60% of the birds sent to cleaning centres

survived the cleaning process and were released, but success varied greatly between species – the mute swan surviving well, but birds such as the red-throated diver having a very poor survival rate during cleaning. Recent work in the USA has shown that several bird species have very poor survival rates following cleaning and release. A study was commissioned by the Sea Empress Environmental Evaluation Committee (SEEEC) to analyse previous data on guillemots – the most common species oiled around the UK. This showed that more than 70% of the cleaned birds died within 14 days of release and only 3% survived for two months or more.

A report on the spill and its consequences was prepared by the Sea Empress Environmental Evaluation Committee (SEEEC), an independent committee set up on 27 March 1996 by the UK Government. The committee’s full report described the impact the oil had on the environment, both at sea and along the shore. It looked at the response to the spill – the clean-up operation, the environmental monitoring programme and the cleaning of oiled birds – and recommended changes in the arrangements for assessing and responding to future spills.