Leading world experts in oil spill response have agreed a series of recommendations to deal with future spills of high density oil during the International Maritime Organization’s Third R&D Forum on High Density Oil Spill Response, held from 11-13 March in Brest, France, following the generous offer of the French Government to host the Forum.
Large quantities of high density oil are carried by ships either as cargo or as fuel (bunkers). This oil’s characteristics, including high viscosity and tendency to sink, present particular challenges for clean-up operations in the event of an accidental spill at sea. The recommendations adopted by the Forum include the development and testing of new system
s for detection and treatment of high density oil spills and the sharing of technical expertise between IMO, Governments and industry (to include oil producers, importers and exporters, and those involved in oil spill response).
Although the safety standards of ships continue to improve and accident rates are falling, accidents such as those involving ships like the Nakhodka in Japan, the Erika off the coast of Brittany and more recently the Baltic Carrier in the Baltic Sea confirmed the urgent need for further development and dissemination of techniques to enable coastal States to respond rapidly and effectively to spills of high density oils. In addition to technological development, the Forum also focused on the operational aspects of combating oil pollution, including training and the effective use of equipment.
Recent years have seen a number of significant developments in this field and, in accordance with the 1990 International Convention on Oil Pollution Preparedness, Response and Co-operation (OPRC), Governments and IMO are playing an active role both by promoting R&D and exchanging information.
Recommendations adopted by the R&D Forum included:
Detection of high density oil spills
- IMO, Governments and industry to co-operate internationally in the development of laser and sonar technology for detecting high density oil spills.
- Governments and industry to validate use of sensors in practice (during actual oil spills).
- Governments and industry to facilitate the testing of prototype systems (systems in development) on actual oil spills.
Modelling of high density oil spills
- Governments to facilitate the validation of modelling systems (such as computerised systems to predict the drifting oil slicks) during actual oil spills.
- Coastal States should encourage oil spill responders to co-operate with modellers.
- IMO’s Marine Environment Protection Committee (MEPC) should use the OPRC Convention as the basic framework to facilitate these recommendations.
Behaviour and fate of high density oil spills
- IMO, Governments and industry to ensure better dissemination of practical knowledge and experience of the behaviour and fate of high density oils, through an international guidance document.
- Much research has been done on emulsified fuel oil, but IMO and Governments need to ensure much wider and better dissemination of the information.
- IMO and the International Standardisation Organization (ISO) to develop internationally recognized definitions for the terms overwashing, submergence and sinking.
- Studies on features of overwashing, submergence and sinking are preliminary and need to be confirmed - and based on this work, simple tools/guides need to be developed.
- There is a need for focussed testing to confirm predictions, from which guidelines could be developed for oil spill responders.
- Current research on dispersant effectiveness needs to focus on determining limits and this information needs to be disseminated to promote proper use.
- Further research is needed on the variability of different high density oils and their properties - reference should be made to existing knowledge and IMO, Governments and industry need to collate more and comprehensive information on high density oils. A range of tests to assess high density oil properties already exist - but further work is needed to validate the tests.
Containment and recovery of floating high density oil
- IMO, Governments and industry to improve international co-operation in developing and testing operational high density oil collection and pumping systems.
- IMO, Governments and industry to consider sharing test facilities and to facilitate joint field trials of complete recovery systems.
- IMO, and the ISO to develop equipment testing parameters, such as standard viscosity and temperature ranges, to accelerate R&D collaboration.
- IMO and ISO to develop guidelines for evaluating recovery system performance to assist in proper selection and use in oil spills.
- IMO to facilitate the better sharing of scientific and technical information during spills and with post-incident reports.
- Regions should evaluate the risks and benefits of response options and consequences.
- Governments and industry to ensure that risk/benefit evaluations include environmental, economic, and social considerations.
Recovery of sunken high density oil
- Industry and Governments to develop deep water automotive systems and wreck detection at depths greater than 2,000 metres.
- Governments to establish an inter-Governmental initiative to investigate the threat of elderly wrecks in coastal waters.
- Industry to develop survey sonar sensors for locating presence of oil through metal/tanks; to make use of advances in digital video imaging and to look at ways of measuring quantities of oil remaining in wrecks.
- Industry to develop alternative methods to steam heating to achieve a viable flow rate in order be able to pump oil from greater depths.
- Industry to develop safety equipment complementary to the development of new recovery technologies.
The recommendations from the R&D Forum will be submitted to the MEPC at its 48th session in October 2002 for consideration and action by IMO Member States.
Funding for the R&D Forum, which had a total budget of more than US$200,000, came from a number of government and industry sources, including Canada, France, Germany, Italy, the Netherlands and the USA, the European Commission as well as the Nippon Foundation of Japan. Industry sources include the Independent Tanker Owners’ Pollution Federation (ITOPF), the International Petroleum Industry Environmental Conservation Association (IPIECA), the Institute of Marine Engineering, Science and Technology (IMarEST) and the oil company BP.
The R&D Forum was attended by some 300 delegates from 70 countries. The delegates included 35 participants from developing countries sponsored by IMO’s Technical Co-operation Programme and other sources. The R&D Forum was chaired by Mr. Tom Allan of the United Kingdom, chairman of IMO’s Maritime Safety Committee.
A further 200 delegates attended a programme of events, held alongside the R&D Forum, dedicated to maritime safety and the protection of the marine environment, organized by the Brest Urban Community, in co-operation with IMO, the European Commission and the following organizations: CEDRE (Centre de Documentation de Recherche et d’Expérimentation sur les pollutions accidentelles des eaux/Centre for Research into Accidental Pollution of the Seas), SYCOPOL (French Oil Spill Control Association), BOSCA (British Oil Spill Control Association), and NOSCA (Norwegian Oil Spill Control Association).
High density oil
High density oils include around 600 million tonnes of residual fuel produced and consumed in the world each year, used mostly for power generation. High density fuel oils are produced from residues from various refinery processes and are also known as heavy fuel oils. Some 140 million tonnes of marine bunker fuel oils
are consumed annually, the majority of which is heavy fuel oil. A large ship powered by diesel engines may consume 150 tonnes of fuel oil per day and may carry up to 3,000 to 4,000 tonnes of this oil as fuel. Heavy fuel oil tends to be cheaper than distillate (lighter) fuel oils.
The characteristics of heavy fuel oil when spilled at sea – such as occurred during the Erika and Baltic Carrier incidents – have implications for response and clean-up operations. These characteristics include:
- High viscosity (relates to ability to be poured) – implications for pumping. Viscosity of any oil decreases as temperature is raised – heavy fuel oil may need to be heated to be pumped. Viscosity is more pronounced in cold waters and winter months.
- May be solid or semi-solid at typical sea temperatures – this can have advantages if it is possible to scoop up quantities of oil in calm seas. Similarly, removal of heavy fuel oil from beaches with hard-packed sand is normally straightforward. Penetration into sandy beaches is likely to be minimal – but care must be taken if mechanical diggers are used so as not to mix oil with sand.
- Highly viscous oil tends to attach itself firmly to hard surfaces, making clean-up difficult on rocky shores. However, when the oil has emulsified with water it may not adhere so readily.
- Heavy fuel oils tend to be less toxic than crude oils and some other refined products – but strong adhesive properties and persistence may have greater impact on mammals and seabirds.
- Spilled oil is heavy (high specific gravity) – tends to float low in the water – this can make recovery using skimmers difficult (whereas skimmers may be more effective for “lighter” oils).
- It may be hard to assess where the oil is from the air because the oil is not floating on the surface – when oil is visible on surface, it may not be possible to assess thickness of oil patches and therefore quantity of oil spilled.
- Movement of heavy fuel oil may be difficult to predict as wave action may carry it below the surface.
- Sunken heavy fuel oil may have significant impact on seabed resources and fishing and mariculture activities.
- Persistent – heavy fuel oils do not disperse naturally in a significant manner and oil spill dispersants may prove ineffective.
- Spilled heavy fuel oil may drift long distances and impact on coasts - with associated high compensation and clean-up costs.
- The precise properties of the particular heavy fuel oil spilled, as well as prevailing weather conditions, may have a significant impact on choice of response/clean-up operations as well as on the ultimate success or otherwise of the clean-up operation.
The International Tanker Owner’s Pollution Federation Limited (ITOPF) indicates that of some 450 spills attended by its staff in the last 25 years, about 40 per cent have involved medium or heavy grades of fuel oil, either carried as cargo or used by larger vessels as bunker fuel. In the last two years, half of all oil spills attended have involved heavy fuel oils.
IMO has recognized the problem posed by spills of oil carried as bunkers – the International Convention on Civil Liability for Bunker Oil Pollution, adopted in March 2001, will enter into force 12 months after ratification by 18 States, including five States with ships whose total gross tonnage is not less than one million.