UK GOVERNMENT AND INDUSTRYRESPONSE TO SEA EMPRESS INCIDENTDAVID SALTOPERA TIONS MANAGEROIL SPILL RESPONSE LIMITEDSOUTHAMPTONENGLAND

On 15th February 1996 at 2007 hours the tanker Sea Empress grounded in theapproaches to Milford Haven, West Wales. The vessel was carrying 131,000 tons ofForties blend crude oil destined for the Texaco Pembroke Refinery. Immediate
notification of the incident was received by Milford Haven Port Authority and the local
Marine Rescue Co-ordination Centre. The vessel grounded on Middle Rock, anunderwater obstruction just out of the main Channel.
Location of Sea Empress grounding

The vessel suffered substantial damage to the starboard side of the hull leading to asignificant release of cargo. Early estimates of the release estimated the quantity of5000 cu, m but observations at first light revised these estimates to 2000 cu. m..
The vessel adopted an 18 degree list following the grounding. At the same time thecargo pump room was flooded with crude rendering the cargo transfer system
inoperable. These factors, combined with the heavy swell in the entrance to the harbour,
made initial salvage plans very complex. The actual salvage operation is currently
being considered by the Marine Accident Investigation Branch at the time of writing
this paper. It would be inappropriate to consider this aspect of the incident until thisreport is officially released.

THE OIL SPILL
A total of 72,000 cu. m. of Forties Blend Crude Oil was lost from the Sea Empress alongwith 360 cu. m. of heavy fuel oil contaminating over 100 beaches along a coastline of
200 km in length.
Initially the coastline within Milford Haven was heavily oiled and then much of the oil
moved south and east affecting long stretches of the Pembrokeshire coast as far asPendine Sands in Carmarthen Bay.
Some oil reached Skomer and Skokholm Islands and entered St. Brides Bay.
It is estimated that 70% of the total amount of oil reaching the cost occurred on 27th
February when large quantities of emulsion came ashore along the western half ofCarmarthen Bay.
Heavy fuel oil was released on the evening of 21st February which impacted beaches
within the Haven, small quantities were released when the ship was moved at laterstages in the incident.
LOCAL ENVIRONMENTAL SENSITIVITIESThe coastline of West Wales is an area of outstanding natural beauty and scientificinterest. The rugged coastline has a wide range of habitats such as rocky shores, sand,shingle and gravel beaches, saltmarshes and mudflats. The area is rich in bird life andsupports an extensive commercial fishing and shellfish industry. Tourism is a major
contributor to the local economy along with visitors to the region to study the local
environment.
Within the area affected by the spill there were 30 sites of Special Scientific Interest(SSI); 2 National Nature Reserves (NNR) and one of the UK's three marine Nature
Reserves (MNR).
Environmental Sensitivities

The islands off West Wales support the greatest concentration of seabirds in Southern
Britain and there is European Special Protection status for Skomer, Skokholm andGrass Holm. There are Special Protection Areas along the Castlemartin Peninsula andmany other conservation areas along the coast from Gower to St. David's Head.
The Pembrokeshire Coast National Park is one internationally recognised for its
ecological richness.
INITIAL RESPONSE
UK Government
Notification of the UK Government Marine Pollution Control Unit occurred throughthe Coastguard Marine Rescue Co-ordination Centre. A Cessna 404 aircraft waslaunched within 30 minutes and flown to Southampton to collect MPCU
representatives. At the same time DC3 spray aircraft were mobilised to Haverfordwest
Airfield. These aircraft form the primary response strategy of the UK Government,
secondary response options being mechanical containment and recovery and shoreline
clean-up.
Industry Response
Under the Milford Haven Standing Conference oil pollution plan it is accepted that thefacility which is receiving the cargo, there being three operators within Milford Haven,will provide the initial response to an incident. In this instance, Texaco had theresponsibility, and mobilised their local response. At the same time Oil Spill Response
Limited, an industry co-operative based in Southampton, was activated. Five response
packages were deployed to site arriving in Wales at 0300 hrs on 16th February.
INITIAL ASSESSMENT
At first light an assessment of the situation was made. The initial release, which
occurred on the incoming tide, was estimated at 2000 cu. m.. This oil moved into theHaven, this unfortunately precluded the use of dispersant as the oil fell within anexclusion zone set out by the Ministry of Agriculture Fisheries and Food. The use ofdispersants was prohibited within 1000m. of the coastline or 750m. of any islands.
Subsequently the primary response to the oil pollution was delayed and the primary
action focused on the clean up of the oil in West Angle Freshwater West and Angle Bay.
MARINE RESPONSE
The Government containment and recovery equipment was mobilised from thePollution Centre which was fortuitously located in Milford Haven. At the same timeship to ship transfer equipment was moved from the Centre to the stricken vessel.
It was determined at this time that additional marine recovery systems would berequired and work commenced to mobilise a number of large scale recovery systems.
These resources came from the commercial sector in the UK or as a result ofInternational agreements within Europe (Bonn Agreement).
UK vessels
Briggs Marine - Forth Explorer
Gulf Offshore - Sefton Supporter
Both of these vessels were engaged in standby support duties in Liverpool Bay area.
UK Government gave permission for these vessels to be released from their duties andmobilised to the spill. In conjunction with these major vessels two Port Authority
vessels, Sea Mop and Sea Sweep were engaged in response operations within theconfines of the Port area.
European vessels
A number of response vessels were taken from European countries within the Bonn
Agreement. The Dutch provided two dredging vessels equipped with Marflex Arm
recovery systems; additionally the French Navy deployed vessels from the CEPOC
organisation with a recovery system.
As these vessels were being mobilised to the site a number of events were occurring atthe casualty site. The vessel, due to the list, was unable to be maneuvered into a safelocation. The weather also deteriorated on day 3 of the incident with a south westerly
Gale Force 8-9 gale developing. This weather, and an inability to control the vessel led
to subsequent groundings and further oil loss. The tidal range at this time was 7.5
metres, ultimately the vessel became lodged on a pinnacle of rock and, as the tide ebbed,
a release of 20,000 cu. m. occurred from the vessel. This was repeated through the next
two subsequent tidal cycles.
AERIAL DISPERSANT APPLICATION
By this time the oil had moved outside the dispersant exclusion zone and full scaleaerial application of chemical dispersant had commenced. Forties Blend crude oil isparticularly amenable to chemical dispersion and the strategy proved very effective in
reducing the oil which impacted the shore. This is clearly in contrast with the oil spilledfrom the Nakhodka, where the oil would not disperse readily and, once the emulsions
had formed, would be totally resistant to chemical response.
In total some 430 tons of dispersant was applied on the spilled oil, this strategy
significantly reduced the quantity of oil reaching the shoreline.
As the operation continued the Aerial Dispersant Delivery system or Adds Pack wasdeployed. These units, which are operated by Oil Spill Response Limited, East Asia
Response Limited and Clean Caribbean Co-operative are large-scale systems capable ofdelivering large quantities of dispersant chemicals.
Another successful part of the operation was the use of in-Weld monitoring of theresults of the dispersant application. The availability of scientific information
substantially improved the acceptance and validity of the strategy.

SPILL MANAGEMENTThe UK Government has adopted a unified command type of approach to spill
management to deal with oil which impacts the shoreline.
This team was based in the offices of the Milford Haven Port Authority and was divided
functionally into several areas:nnnnn

Management
TechnicalEnvironment
Procurement
SupportThe overall activity was supervised by the Management Team who had responsibility
for setting clean-up strategy, Health and Safety and reporting to the public.
Response Organisation

The technical and environment team worked closely together to assess the degree ofpollution of each of the beaches and to choose the best clean-up techniques taking intoaccount what was technically feasible and environmentally sound. Equipment tosupport the clean-up was provided by UK Government, OSRL or local suppliers.

THE CLEAN-UP OPERATIONThe clean-up strategies adopted during the clean-up operation varied considerably
depending upon the type of shoreline, the degree of oiling, the environmental oramenity status of the beach and the logistical practicalities of access.
All decisions on the response strategies were made in the technical and environment
teams to ensure that the most appropriate and least damaging techniques wereadopted.
With over 200 km of shoreline affected a whole range of shoreline types werecontaminated.
The substrate type determines the technique that might be effective in removing oil.
The following table shows the techniques that were applied.

The very rugged and varied coastline made access to the shoreline difficult in someareas and virtually impossible in others. Very serious logistical challenges werepresented to the response teams. In total some 950 persons were involved in the clean
up efforts. These personnel were taken from the local Authority who have theresponsibility for shoreline clean up, from Industry through a mutual aid agreement
which has been set up within the UK and from local labour available in the region. Allof these responders required logistical support in terms of protective clothing, food anddrink, shelter, transportation. Each of the teams required management andsupervision to ensure their safety and maintain their commitment to the task at hand.
The initial targets set in the clean up were to have the key resort beaches in a state
which was acceptable for use by the Easter vacation period. His initial phase of theclean up was achieved, subsequent fine polishing of the beaches continued throughout
the summer and concluded in November 96.
The period was prolonged due to patches of oil being uncovered and released during theequinoctial gales in October.

One of the interesting factors in the clean up was the continued mobility of the oil.
Even in its emulsified state it did not tend to 'stick' in any particular location, it
retained its mobility. This aided the clean up efforts by making the oil easy to remove,the negative side of this property was that the oil tended to move with each subsequent
tide.
WASTE DISPOSAL
The issue of waste disposal has always been one of the greatest problems in oil spill
response, The Sea empress incident generated about 20,000 tons of liquid waste and11,000 tons of solid waste. A temporary storage pit of 3,000 tons for almost 3,000 tons of
oiled beach material was constructed in the dunes behind the beach. Liquid waste
recovered at sea was taken by sea to Milford Haven and transferred to the Texaco
Refinery. Liquid waste recovered from the beaches was taken by road to the nearest of
the three refineries in the Haven. In total about 20,000 tons were processed. The oiled
beach material presented much more of a problem, not least because of the mixture ofmaterials contained in the waste. The majority of this waste was treated by land
farming in Texaco Refinery, the remainder being transported to a land fill site.
In this instance, by good fortune the waste disposal problem was adequately providedfor. If the spill had occurred some distance either North or South of the actual spill
location the problems would have been enormous.
CONCLUSIONSIn summary the pollution response element of the Sea Empress incident was generally
considered to be a cost effective and reasonably efficient operation. Shortfalls wereidentified in the plan and the management structure of the control organisation, but
this is only to be expected given the amount of exposure that most people get of an oil
spill situation. The media profile of the response operation was quite modest incomparison to other spill incidents, although it is recognised that the majority of thecontroversy was focused on the salvage operation.
The use of dispersants, the key response strategy of the UK, proved to be a great benefit
in the response. This was further underlined by undertaking scientific monitoring of
the dispersant operation, validating the use of the strategy and allowing ameasurement of the results achieved.

The table below shows a budget mass balance for the spill and allows a number ofinteresting comparisons to be made. It should be noted that the relationships between
costs and strategies are not fixed and can vary enormously in each case.