The Oil Pollution Act of 1990: A Decade Later

Analysis of oil spills data confirms that accidental oil spills are natural phenomenon and that there is a relationship between accidental oil spills and variables like vessel size, vessel type, time and region of spill. The volume of oil spilled bears relationship with the volume of petroleum imports and domestic movement of petroleum and proportion of large oil spills. Finally, navigational risk increases with increase in marine traffic and is also determined by variables like hydrographic and meteorological conditions, water configuration, maneuvering space, obstructions and nuisance vessels. The Oil Pollution Act, 1990 (OPA 90) was passed by the US Congress in the aftermath of 11 million gallon spill of crude oil in Prince William Sound, Alaska. The objective of OPA 90 was to minimize marine casualties and oil spills by addressing preventive, protective, deterrent and performance aspects of accidental oil spills. The arm of various regulations like double-hull tankers and vessel response plans extended to both US flagged and foreign-flagged tank vessels. The cost–benefit analysis of major regulations shows that the estimated costs exceed estimated benefits. We observe from USCG data on oil spills by size, by vessel type, Coast guard district and type of petroleum product that there have been significant reductions in the number and the quantity of oil spills. Our regression results show that the quantity of oil spilled increases with increase in oil imports but increases at a decreasing rate. The quantity of oil spilled decreases with increases in the domestic oil movements. Furthermore, percent of oil spills larger than 10,000 gallons also increases the potential quantity of oil spilled. OPA 90 has been a deterrent to accidental oil spills but the finding is not conclusive.     

Comparative occurrence rates for offshore oil spills

Estimates of occurrence rates for offshore oil spills are useful for analysis of potential oil spill impacts and for oil spill response contingency planning. As the Oil Pollution Act of 1990 (U.S. Public Law 101–380, 18 August 1990) becomes fully implemented, estimates of oil spill occurrence will become even more important to natural resource trustees and to responsible parties involved in oil and gas activities. Oil spill occurrence rate estimates have been revised based on U.S. Outer Continental Shelf platform and pipeline spill data (1964–1992) and worldwide tanker spill data (1974–1992). These spill rates are expressed and normalized in terms of number of spills per volume of crude oil handled. The revisions indicate that estimates for the platform spill occurrence rates declined, the pipeline spill occurrence rates increased, and the worldwide tanker spill occurrence rates remained unchanged. Calculated for the first time were estimates of tanker and barge spill rates for spills occuring in U.S. waters, and spill occurrence rates for spills of North Slope crude oil transported by tanker from Valdez, Alaska. All estimates of spill occurrence rates were restricted to spills greater than or equal to 159 m³ (1000 barrels).     

Update of Comparative Occurrence Rates for Offshore Oil Spills

Estimates of occurrence rates for offshore oil spills are useful for analyzing potential oil-spill impacts and for oil-spill response contingency planning. With the implementation of the Oil Pollution Act of 1990 (US Public Law 101-380, August 18, 1990), estimates of oil-spill occurrence became even more important to natural resource trustees and to responsible parties involved in oil and gas activities.Oil-spill occurrence rate estimates have been revised based on US Outer Continental Shelf (US OCS) platform and pipeline spill data (1964 through 1999), worldwide tanker spill data (1974 through 1999), and barge spill data for US waters (1974–1999). These spill rates are expressed and normalized in terms of number of spills per volume of crude oil handled. All estimates of spill occurrence rates were restricted to spills greater than or equal to 1000 barrels (159 m³, 159 kl, 136 metric tonnes, 42,000 US gallons).The revisions compared to the previously published rates calculated through 1992 (Anderson and LaBelle, 1994) indicate that estimates for the US OCS platform spill occurrence rates continue to decline, primarily because no spills have occurred since 1980. The US OCS pipeline spill occurrence rates for spills greater than or equal to 1000 barrels remained essentially unchanged. However, the rate for larger OCS pipeline spills (greater than or equal to 10,000 barrels) has decreased significantly. Worldwide tanker spill rates, rates for tanker spills in US waters, and rates for barge spills in US waters decreased significantly. The most recent 15-year estimates for 1985–1999 (compared to rates for the entire data series) showed that rates for US OCS platforms, tankers, and barges continued to decline.     

Australia's National Plan to Combat Pollution of the Sea by Oil and Other Noxious and Hazardous Substances – Overview and Current Issues

Australia's National Plan to Combat Pollution of the Sea by Oil and Other Noxious and Hazardous Substances (the National Plan) has operated since 1973. The objectives of the National Plan are based on Australia's obligations as a signatory to the International Convention on Oil Pollution Preparedness, Response and Co-operation 1990 and a responsibility to protect natural and artificial (man made) environments from the adverse effects of oil pollution and minimise those effects where protection is not possible.The Australian Maritime Safety Authority (AMSA) is the managing agency of the National Plan, working together with the States and Northern Territory governments, other Commonwealth agencies, ports, and the shipping, oil and exploration industries, to maximise Australia's marine pollution response capability.The 1990s have been a period of significant change for oil spill response arrangements in Australia. The National Plan was extended in 1998 to cover chemical spills and is currently in the process of implementing the oil spill response incident control system (OSRICS). A fixed wing aerial dispersant spraying capability was implemented in 1996 and a research and development program has been put in place. The development of a computer-based National Oil Spill Response Atlas was a major project completed during 1999.     

Past in situ Burning Possibilities

This study evaluated the feasibility of conducting in situ burning (ISB) using current technology on post-1967 major oil spills over 10 000 barrels in North America and over 50 000 barrels in South America and Europe. A diverse set of 141 spills representing various combinations of parameters affecting spill responses (e.g., spill size, oil type, weather conditions, sea temperature, and geographic location) were evaluated using four “Phase I” criteria: Distance to populated area, oil weathering, logistics, and weather conditions. In Phase I, a spill that failed to meet one of the four criteria was considered an “unsuccessful” candidate for ISB. In total, 47 of the 141 spills passed the Phase I analysis. The potential effect of the plume on populated areas was the most significant of the four Phase I criteria; 59 of the 141 spills did not pass Phase I because the incident occurred near a sizable city. Spills that met all four criteria were further evaluated using a “Phase II” analysis that applied additional criteria and considered individual spill circumstances to determine if the spill should be rated as a “successful”, “marginal call”, or “unsuccessful” ISB candidate. Fourteen spills were ultimately determined successful in the Phase II analysis, and 12 were designated marginal calls.     

An approach to evaluate the application of the vulnerability index for oil spills in tropical Red Sea environments

The Egyptian national marine oil pollution contingency plan was urgently initiated after the Nabila oil spill in 1982, to provide an estimate of its environmental effects on the Egyptian Red Sea coastal areas and to determine geomorphological features and cuastal processes, together with physical, chemical and biological baseline data for this tropical environment.The ‘Vulnerability Index’ (VI) was applied to evaluate and calibrate the effect of the Nabila oil spill on the Egyptian Red Sea Coastal area. A detailed in situ coastal survey was conducted during two visits in November 1982 and May 1983 to 80 shore sites from Suez to Ras Banas to monitor the oil pollution and to apply the ‘Vulnerability Index’. A comparative assessment of the index over time by comparing it with a quick ground inspection in November 1993 to some sites to evaluate the applicability of this index for oil spills in such environments. In addition, the physical effects of fresh and weathered crude oil and/with dispersant on water filtration by different beaches were preliminary studied.The geomorphological/Vulnerability Index results show that most of the Egyptian Red Sea coastal environments have medium to high vulnerability to immediate and medium term oil spill damage. The oil pollution spread estimated to be 250 km south of the oil spill and about 200 km north of it. The quantity of oil along the shoreline was reduced by about 60% due to natural and authorities clean up. The third survey after 11 years showed that the VI could be used as a predictive tool for assessment of oil spill effects on such tropical environments.     

Summary of Development and Field Testing of the Transrec Oil Recovery System

This paper summarizes the development, field testing and performance evaluation of the Transrec oil recovery system including the Framo NOFO Transrec 350 skimmer and multi-functional oil spill prevention and response equipment and presents performance data, not published before, from full-scale experimental oil spills in the North Sea from 1981 to 1990. The rare data provides useful information for evaluation of mechanical clean-up capabilities and efficiency, in particular, for responders who are using this equipment in many countries around the world.The development of the Transrec oil recovery system represents one of the most comprehensive efforts funded to date by the oil industry in Norway to improve marine and open ocean oil spill response capabilities. The need for improvements was based upon early practical user experience with different oil recovery systems, and test results from experimental oil spills in the North Sea.The result of the development efforts increased: (1) skimmer efficiency from approximately 15–75% (it reached 100% under favorable environmental conditions); (2) oil emulsion recovery rate from approximately 20–300 m³/h; (3) recovery system efficiency from approximately 15–85% in 1.5 m significant wave height; (4) oil emulsion thickness from approximately 15–35 cm; (5) weather-window for mechanical recovery operations from 1.5 to 3.0 m significant wave height; (6) capability for transfer of recovered oil residue to shuttle tankers in up to 4 m significant wave height and 45 knot winds; (7) capability for operations at night.The new Transrec oil recovery system with the special J-configuration virtually eliminated skimming operation downtime, and damage to booms and equipment failures that had been caused by oil spill response vessel (OSRV) problems with maintaining skimming position in the previous three-vessel oil recovery system with the boom towed in U-configuration. The time required to outfit OSRVs dropped from approximately 30–<1 h, reducing time from notification to operation on site by more than 24 h.Improvement in oil recovery resulted in the acceptance of a new oil spill preparedness and response plan. The new plan reduced the need for oil recovery systems from 21 to 14, towing vessels in preparedness from 42 to 18, and personnel on stand-by from 135 to 70, which subsequently reduced the total contingency and operational costs by almost 50%. These cost reductions resulted from lower contingency fees for personnel, fewer towing vessels on stand-by, less expensive open ocean training and exercises, less equipment and reduced storage space to lease, and simplified equipment maintenance.     

溢油监测技术在石油石化企业环境风险防控中的应用

针对石油石化企业的溢油风险,提出企业在厂区雨水系统、外排口、涉水生产设施、环境敏感受体、溢油事故应急处置5类场景下的溢油监测需求,总结了溢油监测技术的类型和特点,介绍了可见光、红外、紫外、荧光、高光谱、微波辐射、雷达、电磁能量吸收等溢油监测技术的应用现状和优缺点。提出:企业溢油监测系统可分为企业内部溢油风险分级管控监测、企业边界的溢油风险报警监测、敏感环境监视的风险预警监测、溢油事故应急救援的溢油处置监测4个层次的运行模式。     

Australia’s Tyranny of Distance in Oil Spill Response

In view of the quantity of oil spilled, smaller spills generally receive less attention than headline grabbing incidents such as the “Amoco Cadiz”, “Exxon Valdez”, “Braer” and “Sea Empress”. The latter incidents involve the loss of significant quantities of oil, the establishment of relatively complex spill response management structures and the involvement of significant numbers of personnel and equipment. As such, large spills from tankers have the potential to create problem areas, for example in establishing and maintaining effective communications, logistics and resource management systems.In general terms spill response personnel are well aware that large spills come complete with significant operational and administrative problems, however what may not be so well recognised is that smaller spills also have the potential to present response personnel with their own unique problems.One of the major problems to be overcome when responding to spills in Australia is the “tyranny of distance”. In quite a few responses, Australian oil spill response managers have had to move personnel and equipment thousands of kilometres to provide an effective outcome. This paper outlines a range of problems that have been encountered by Australian personnel over the years. These include health and safety, communications, logistics and equipment issues.For the purpose of this paper a “smaller” spill has been defined as one involving a discharge of less than 1000 tonnes of oil.     

Maersk Navigator oil spill in the great channel (Andaman Sea) in January 1993 and its environmental impact

Observations on oil slicks, tar residues and dissolved petroleum hydrocarbons (DPH) shortly after the oil spill resulting from the tanker accident in January 1993 showed negligible impact on the Indian EEZ of the Great Channel (Andaman Sea). DPH were between 0.31 and 1.85 μg l⁻¹ in the area examined. Tar residues were absent throughout the study area. Prevailing NE wind with resultant SW surface current appears to have pushed the oil patches out towards the open Indian Ocean.A follow-up survey of the same area was carried out in September-October 1993 and observations similar to those made during the earlier survey were recorded. The zooplankton biomass had increased considerably during the interval between the two surveys, but this was probably due to seasonal changes and natural variability.The spill did not cause any perceptible impact on the environment.     

The Application of Strict Criminal Liabilities to Spillage of Oil: The Practical Impact on Effective Spill Response

The Federal Water Pollution Control Act as amended by the Oil Pollution Act of 1990 provides criminal penalties in oil spills that result from criminal activity, gross negligence or willful misconduct on the part of the spiller. Nevertheless, the Department of Justice has seen fit to reach into unrelated legislation to potentially apply strict criminal liability to any oil spill regardless of intent.Strict criminalization of accidental oil spills is demonstrably counterproductive to effective protection of the environment from the effect of spills since it poses a serious impediment to cooperation and coordination by and between those charged by law to respond to them. This impediment is particularly dangerous since it threatens the proper functioning of the inherently sensitive “troika” Unified Command Structure that has evolved in spill response management in response to OPA-90 management requirements.Introduction of strict criminal liability for accidental spills is also particularly troublesome in that it must enlist unrelated law to influence an area that has been addressed specifically by legislation designed for that purpose; legislation that has worked well in the past 30 years to both regulate the target activities while successfully achieving the objective of protecting and improving environment quality.     

Biodegradation of Dispersed Forties Crude and Alaskan North Slope Oils in Microcosms Under Simulated Marine Conditions

For oil spills in the open sea, operational experience has found that conventional response techniques, such as mechanical recovery, tend to remove only a small fraction of oil during major spills, a recent exception being the Mississippi River spill in Louisiana [Spill Sci. Technol. Bull. 7 (2002) 155]. By contrast, the use of dispersants can enable significant fractions of oil to be removed from the sea surface by dispersing the oil into the water column. It is thought that once dispersed the oil can biodegrade in the water column, although there is little information on the mechanism and rate of biodegradation. Two studies were undertaken on dispersion, microbial colonisation and biodegradation of Forties crude and Alaskan North Slope (ANS) oils under simulated marine conditions. The study using the Forties crude lasted 27 days and was carried out in conditions simulating estuarine and coastal conditions in waters around the UK (15 °C and in the presence of nutrients, 1 mg N-NO₃/l), while the ANS study simulated low temperature conditions typical of Prince William Sound (8 °C) and took place over 35 days. The results of both studies demonstrated microbial colonisation of oil droplets after 4 days, and the formation of neutrally buoyant clusters consisting of oil, bacteria, protozoa and nematodes. By day 16, the size of the clusters increased and they sank to the bottom of the microcosms, presumably because of a decrease in buoyancy due to oil biodegradation, however biodegradation of n-alkanes was confirmed only in the Forties study. No colonisation or biodegradation of oil was noted in the controls in which biological action was inhibited. Oil degrading bacteria proliferated in all biologically active microcosms. Without dispersant, the onset of colonisation was delayed, although microbial growth rates and population size in ANS were greater than observed with the Forties. This difference reflected the greater droplet number seen with ANS at 8 °C than with Forties crude at 15 °C. Although these studies differed by more than one variable, complicating comparison, the findings suggest that dispersion (natural or chemical) changes the impact of the oil on the marine environment, potentially having important implications for management of oil spills in relation to the policy of dispersant use in an oil spill event.     

Oil Spills and the Social Amplification and Attenuation of Risk

The news media and environmental groups are frequently blamed for public overreaction to unfortunate events like major oil spills; an example of the social amplification of risk. A disconnect between public views regarding spill consequences and necessary remedies on the one hand, and expert opinion on these same questions on the other, is a frequently identified consequence of this social amplification. A more comprehensive examination of the ways in which scientific messages can fail to inform the public or to rationalize public policy suggests however that a more complex phenomenology is at work. Perceived risks can be attenuated as well as amplified, and many organizations besides the news media contribute to the shaping of public risk attitudes. As a result, social and political questions of blame can prove difficult to disentangle from scientific questions of impact. Both social amplification and social attenuation of messages about the risks of oil production and transport are evident in public responses to the Exxon Valdez spill, and both continue to affect the debate about oil production and its transport by sea today. Oil-spill science has had mixed success in modulating these risk concerns, as the conduct of oil-spill science has itself felt the effects of risk amplification and attenuation. Because these difficulties are bound up in questions of social trust, institution building is seen as the best long-term strategy for redress. The Prince William Sound Regional Citizen’s Advisory Council offers a hopeful example that such institution building can occur, given sufficient motivation, resources and the means and time for diverse interests to develop a shared vision of the risks to be addressed.     

Looking to the Future––Setting the Agenda for Oil Spill Prevention,Preparedness and Response in the 21st Century

The Oil Pollution Act of 1990 (OPA 90) was largely driven by the catastrophic EXXON VALDEZ tanker spill and several other major tanker spills that followed in 1989. Under the OPA 90 mandate, the US Coast Guard, in partnership with other Federal agencies and industry have implemented a number of initiatives that have significantly enhanced the national oil spill prevention, preparedness and response capability. Declining trends in the volume of oil spilled into US waters indicates that these initiatives are at least in some measure successful.The Coast Guard is now concerned about what the future may hold in terms of oil pollution threats, and prevention, preparedness and response program shortcomings and opportunities in the future. To address this issue, the Coast Guard, in partnership with other National Response Team agencies and industry, is conducting a Broad-Based Programmatic Risk Assessment to develop a comprehensive vision and strategy for the Oil Spill Prevention, Preparedness and Response (OSPPR) Program in the 21st Century. This study will characterize the current and emerging oil spill threats by source category, assess the potential impacts of these threats to define overall risk, and examine the current and projected effectiveness of OSPPR initiatives in minimizing these risks. Key issues, problems and focus areas will be identified and targeted for follow-on risk analysis and management activities by the Coast Guard and agency and industry stakeholders.     

Prediction of the Dispersal of Oil Transport in the Caspian Sea Resulting from a Continuous Release

A 3-D hybrid flow/transport model has been developed to predict the dispersal of oil pollution in coastal waters. The transport module of the model takes predetermined current and turbulent diffusivities and uses Lagrangian tracking to predict the motion of individual particles (droplets), the sum of which constitute a hypothetical oil spill. Currents and turbulent diffusivities used in the model have been generated by a numerical ocean circulation model (Princeton ocean model) implemented for the Caspian Sea. The basic processes affecting the fate of the oil spill are taken into account and parameterized in the transport model.The hybrid model is implemented for a simulated continuous release in the coastal waters of the Caspian Sea. The potential of the model for the prediction of the advective and turbulent transport and dispersal of oil spills is demonstrated.     

Relative values of damage assessed for the Gulf of Mexico,the Atlantic coast and the Pacific coast

The objective of the present work is to obtain a dollar value as a measure of the relative economic impact of an oil spill at various sites along the coasts of the contiguous United States of America. The model to be used is the NRDAM/CME of the U.S. Department of Interior. The test spills used were 10,000 gallons of No. 2 fuel oil, and of medium crude oil. Both background and tidal currents were suppressed. A wind speed of 10 knots was used; wind direction was chosen to ensure landfall of the oil. Other input variables were taken to be the default values to minimize the number of variables. The locations for the highs and lows of damages assessed are found to be different for the two oils studied. This method may be used as a measure of the relative economic importance of the various natural resources along the maritime coasts of the contiguous United States with respect to oil spills.     

RADARSAT SAR for oil spill response

RADARSAT synthetic aperture radar imagery has been successfully classified to delineate oil slicks on water using training areas for various degrees of oil coverage located within each image. Three and four class schemes have been tested with imagery from the Nakhodka and Milford Haven spills. An interactive graphical editor has been developed using the classified images to re-initialize the SPILLSIM oil spill model during a simulation.     

Photo-oxidation and Photo-toxicity of Crude and Refined Oils

The fate and effects of an oil spill are effected by solar radiation through the action of photo-oxidation and photo-toxicity. Photo-oxidation, an important process in the weathering of oil, produces a variety of oxidized compounds, including aliphatic and aromatic ketones, aldehydes, carboxylic acids, fatty acids, esters, epoxides, sulfoxides, sulfones, phenols, anhydrides, quinones and aliphatic and aromatic alcohols. Some of these compounds contribute to the marine biota toxicity observed after an oil spill. Photo-toxicity occurs when uptake of certain petroleum compounds, e.g. certain polycyclic aromatic hydrocarbons and benzothiophenes, is followed by solar exposure which results in much greater toxicity than after dark uptake. The mechanism of PAH photo-toxicity includes absorbance of solar radiation by the PAH which produces a free radical and this free radical in turn reacts with oxygen to produce reactive oxygen species that can damage DNA and other cellular macromolecules. While most studies on photo-toxicity have been carried out in the laboratory, there are studies showing that water from an oil spill is photo-toxic to bivalve embryos for at least a few days after the spill. Other studies have found that oil contaminated sediments are photo-toxic to several marine invertebrates. More studies are required to determine if marine fauna at an oil spill site are effected by the action of photo-toxicity and photo-oxidation.