Long-term Environmental Impact of Oil Spills

Oil contamination may persist in the marine environment for many years after an oil spill and, in exceptional cases such as salt marshes and mangrove swamps, the effects may be measurable for decades after the event. However, in most cases, environmental recovery is relatively swift and is complete within 2–10 years. Where oil has been eliminated from the scene, the long-term environmental impacts are generally confined to community structure anomalies that persist because of the longevity of the component species.     

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.     

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.     

Langmuir Circulation and the Dispersion of Oil Spills in Shallow Seas

Aspects of Langmuir circulation (Lc) which relate to the dispersion of floating material are reviewed. These include convergence, dispersion by advection (particularly of a plume of floating oil when wind and current are in different directions) and the spread and dispersion by cell instability or breakdown first described by Csanady. There are, however, processes which compete with Lc to diffuse floating material. In shallow tidally mixed seas, where the environmental impact of an oil spill may be greatest, cross-wind dispersion caused by Lc will dominate over that produced by bottom turbulence if the ratio of the wind speed, W, to current, U, is sufficiently large. Observations and rough estimates suggest a transition near W/U=15. A simple model is devised to estimate cross-wind dispersion in shallow unstratified waters when turbulence generated at a flat seabed dominates that produced by Lc, but when the effects of Lc are still evident in aligning filaments of oil, as may commonly be the case in moderate winds in coastal or continental shelf waters.     

South Arne Field Development: An Environmental Impact Assessment of Oil Spills

The South Arne field being developed by Amerada Hess A/S is located in 60 m water depth approximately 200 km from the Danish mainland, in block 5604/29 of the Danish sector of the North Sea.As part of the development of the field, a comprehensive environmental impact assessment has been carried out, including the assessment of the impact from oil spills. The Danish authorities required that a ‘worst case’ oil spill be chosen as the basis for the assessment on birds and aquatic organisms including plankton, fish eggs and larvae and benthos.A well blow-out at the surface was chosen as the worst case for the impact on birds, and a seabed blow-out for aquatic organisms.The oil spill modelling was carried out with the DEEPBLOW, SLIKMAP and OSCAR models from SINTEF. The modelling identified environmentally sensitive areas which could potentially be influenced by an oil spill. These included the Dogger Bank, western Skagerrak, south-western Norwegian Trench, the eastern German Bight and the Wadden Sea.Historical meteorological and hydrodynamic scenarios were chosen from a long period of records to ensure that the plume passed through the environmentally sensitive resource areas.For birds, a scan of the literature and available databases was made to determine the numbers and species of birds in the areas swept by the surface slick, the number of fatalities was estimated and finally the recovery time for each species population was estimated.The impact on aquatic organisms was estimated using the predicted environmental concentration/predicted no effect concentration (PEC/PNEC) method of the CHARM model. This method is normally applied to continuous discharges, but here has been used to estimate the impact of a transient pollution cloud resulting from an oil spill.     

Introduction/Overview to In Situ Burning of Oil Spills

In situ burning is an oil spill response technique or tool that involves the controlled ignition and burning of the oil at or near the spill site on the surface of the water or in a marsh (see Lindau et al., this volume). Although controversial, burning has been shown on several recent occasions to be an appropriate oil spill countermeasure. When used early in a spill before the oil weathers and releases its volatile components, burning can remove oil from the waters surface very efficiently and at very high rates. Removal efficiencies for thick slicks can easily exceed 95% (Advanced In Situ Burn Course, Spiltec, Woodinville, WA, 1997). In situ burning offers a logistically simple, rapid, inexpensive and if controlled a relatively safe means for reducing the environmental impacts of an oil spill. Because burning rapidly changes large quantities of oil into its primary combustion products (water and carbon dioxide), the need for collection, storage, transport and disposal of recovered material is greatly reduced. The use of towed fire containment boom to capture, thicken and isolate a portion of a spill, followed by ignition, is far less complex than the operations involved in mechanical recovery, transfer, storage, treatment and disposal (The Science, Technology, and Effects of Controlled Burning of Oil Spills at Sea, Marine Spill Response Corporation, Washington, DC, 1994).However, there is a limited window-of-opportunity (or time period of effectiveness) to conduct successful burn operations. The type of oil spilled, prevailing meteorological and oceanographic (environmental) conditions and the time it takes for the oil to emulsify define the window (see Buist, this volume and Nordvik et al., this volume). Once spilled, oil begins to form a stable emulsion: when the water content exceeds 25% most slicks are unignitable. In situ burning is being viewed with renewed interest as a response tool in high latitude waters where other techniques may not be possible or advisable due to the physical environment (extreme low temperatures, ice-infested waters), or the remoteness of the impacted area. Additionally, the magnitude of the spill may quickly overwhelm the deployed equipment necessitating the consideration of other techniques in the overall response strategy (The Science, Technology, and Effects of Controlled Burning of Oil Spills at Sea, Marine Spill Response Corporation, Washington, DC, 1994; Proceedings of the In Situ Burning of Oil Spills Workshop. NIST. SP934. MMS. 1998, p. 31; Basics of Oil Spill Cleanup, Lewis Publishers, Washington, DC, 2001, p. 233). This paper brings together the current knowledge on in situ burning and is an effort to gain regulatory acceptance for this promising oil spill response tool.     

Environmental Sensitivity of a Tropical Coastline (Trinidad,West Indies) to Oil Spills

In the wider Caribbean region, Trinidad has been classified as a high risk area for oil spills by the Intergovernmental Marine Consultative Organization. In order to develop an oil spill environmental sensitivity index, the intertidal zones of fifteen representative coastal sites were monitored for physical and biological parameters during the dry and wet seasons. On a scale of 1–10, sheltered habitats with high productivity are the most sensitive to spilt oil with an index value of 10. Exposed habitats with low productivity are the least sensitive with a value of 1. The index applied to coastal habitats in Trinidad is as follows: mangrove swamps (10), coral-algal reefs (9), sheltered rocky coasts (8), sheltered tidal flats (7), mixed sand and gravel beaches (6), sheltered fine to medium-grained sand beaches (5), exposed rocky shores (4), exposed tidal flats (3), exposed medium to coarse-grained sand beaches (2) and eroding wavecut platforms (1). This study demonstrates an approach to effectively combine biological and physical parameters into a single environmental sensitivity index to oil spills.     

Physical Properties and Processes that Influence the Clean Up of Oil Spills in the Marine Environment

Based on a study carried out by the Versuchsanstalt für Wasserbau und Schiffbau, Berlin – VWS for the German Environmental Agency, this report represents an attempt to summarize the knowledge in the Federal Republic of Germany and world-wide concerning the control of hazards from discharged oil and other liquid chemicals after casualties on and in the hydrosphere. Because of technical reasons, control measures can be classified into passive and active types; this classification has been adopted for this report in the following order:

• •Part 1: Passive mechanisms: Booms and barriers.
• •Part 2: Active mechanisms: Recovery devices.
• •Part 3: Other means: Dispersion.
• •Part 4: Control of sinking and/or sunken chemicals.

Part 1 not only evaluates the behaviour of liquid chemicals on water, but also considers the physical fundamentals underlying the functioning of booms and barriers. Some widely used definitions and relations (such as the relationship between the blocking of liquid chemicals and boom draught or efficiency) will be refined. The discussion of the physical fundamentals is presented in the broadest sense and concludes with practical advice on the deployment of booms.Part 2 attempts to standardize recovery devices based on the application of fundamental physical principles. Four classes were identified and have been used to classify pick-up devices. Once again basic physical fundamentals have been presented in a way that facilitates deductions on application possibilities. The evaluation showed that practically only those methods that utilize adhesion and “hole-in-the-water” principles can be operated with sufficient efficiency which, in turn, reflects the world-wide state-of-the-art in equipment development. Special attention has been paid to hybrid systems which utilize both passive and active methodologies.In Part 3, the basics of dispersion of oil and other floating liquid chemicals are considered. It can be shown that mechanical dispersion has the same effect as its chemical counterpart. This relationship recognizes the necessity for applying a mechanical agitator for using dispersants effectively. This strategy calls into question the efficiency of chemical dispersion.Part 4 deals with the behaviour and control options for sinking and/or sunken liquid chemicals. Contrary to the general opinion that liquid chemicals which have disappeared from the surface cannot be controlled, it has been found that, under certain conditions, even these chemicals can be “herded” and recovered. It will be shown that practically the same techniques can be applied to submerged chemicals as has been used for the recovery of floating hazardous substances.     

Environmental Effects of In Situ Burning of Oil Spills in Inland and Upland Habitats

In situ burning of inland and upland habitats is an alternative oil spill cleanup technique that, when used appropriately, may be more environmentally acceptable than intrusive manual, mechanical, and chemical treatments. There have been few published reports documenting the environmental effects of in situ burning in inland and upland habitats. Thus, this study, sponsored by the American Petroleum Institute, used two approaches to increase the knowledge base and improve the appropriate use of in situ burning: (1) detailed review of published and unpublished in situ burn case histories for inland and upland spills; and (2) summaries of fire effects and other information from the literature on fire ecology and prescribed burning. Thirty-one case histories were summarized to identify the state of the practice concerning the reasons for burning, favorable conditions for burning, and evaluations of burn effects. The fire ecology and effects summaries included information from the extensive knowledge base surrounding wildfire and prescribed burning (without oil) as a natural resource management tool, as well as fire tolerance and burning considerations for dominant vegetation types of the United States. Results from these two approaches should improve the application of in situ burning for inland and upland spills.     

The Significance of Oil Spill Dispersants

There is growing acceptance worldwide that use of dispersants to counter the effects of an oil spill offers many advantages and can often result in a net environmental benefit when considered in relation to other response options. A major reason for this growing support and increased reliance on dispersants is the advent of improved dispersant products that are low in toxicity to marine life and more effective at dispersing heavy and weathered oils – oils previously believed to be undispersible. This capability has been demonstrated through extensive laboratory testing, field trials, and dispersant application on actual spills. This paper summarizes recent advances in dispersant R&D and reviews the implications of technology advances.     

The Preparation and Characterization of Polyurethane Foam with Coconut Oil Polyol and Rapeseed Oil Polyol

Journal of Polymers and the Environment - The bio-based acoustic materials have flourished with the future depletion of petroleum resources in recent years. This paper dedicates on the synthesis of...     

Understanding the Causes of Spills From the Supply and Handling of Chemicals at Resource Construction Sites: A Case Study

An intermediate bulk container (IBC) was punctured during its handling, releasing a refined oil product onto land at a large construction site in an environmentally sensitive region of Australia. Understanding and controlling the risks from fuel, oil, and chemical spills on the current project was of critical importance as part of the project's overall approval, and ongoing compliance depended on the project committing to minimizing all chemical and petroleum hydrocarbon spills on the site. The telehandler (forklift) did not pierce the plastic of the IBC directly (as was expected to be the case) but rather one of the tynes caught on the underside of the metal base plate (pallet belly plate), despite numerous controls being in place at the time of spill (to limit the risks of damaging the IBC), revealing a previously unreported mechanism for a fluid spill from handling of petroleum hydrocarbons and related chemicals. The investigation team used a root cause analysis (RCA) technique, based on the fishbone (Ishikawa) diagram, which was undertaken with 12 expert contributors (from the project) to identify the underlying cause: The inspection process was inadequate. This study is a companion to the article published in Winter 2014 in Remediation (Guerin, 2014) covering multiple causes of spills from plant and equipment commonly used on construction and remediation projects. ©2015 Wiley Periodicals, Inc.     

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.     

The Properties of PLA/Oxidized Soybean Oil Polymer Blends

Novel polymer blends based on completely renewable polymers were reported. Polymer blends based on polylactic acid (PLA) and oxidized and hydroxylated soya bean oil polymers were prepared. Plasticization and mechanical strength effect of the soya bean oil polymers on the PLA were observed. Fracture surface analysis of the polymer blends was carried out by using scanning electron microscopy. The PLA blends showed more amorphous morphologies compared to pure PLA. The blends had better elongation at break in view of the stress–strain measurement. Blend of PLA with the hydroxylated polymeric soya bean oil indicated the slightly antibacterial properties.     

采用表面活性剂去除油砂开采尾砂中的油

采用表面活性剂吐温- 80溶液浸取油砂开采尾砂中的油,研究了各工艺条件对除油效果的影响.实验确定的最佳工艺条件:溶液pH为7,反应温度为25℃,搅拌转速为120 r/min,固液比(尾砂与吐温- 80溶液质量比)为1∶5,吐温- 80溶液体积分数为0.20％,振荡时间为2h.在最佳工艺条件下经处理后尾砂中含油量在0.3...     

考虑油滴碰撞聚结的斜板除油过程模拟

考虑离散油滴在油田废水除油过程中发生的油滴碰撞聚结现象,模拟得出斜板除油器内全部油滴的动态信息,用于斜板除油器除油效率的计算.对矩形同向流斜板除油过程的模拟研究表明:油滴的碰撞聚结会增加斜板除油的效率;当废水的原始含油浓度增大时,斜板除油的效率会增大,碰撞聚结对除油效率提高的影响也越大;废水流动速度提高及斜板的倾斜角度增加均会使斜板的除油效率降低,但此时油滴碰撞聚结对除油效率的影响仍很明显.     

The Social and Political Meaning of the Exxon Valdez Oil Spill

In this paper we argue that the Exxon Valdez oil spill gained so much attention because of its setting in Alaska. Alaska symbolizes for many Americans the wilderness or frontier that has long been part of American thought. At the same time, American national development has largely depended on the discovery and use of the nation’s abundant natural resources. The setting of the Valdez spill in the seemingly pristine waters of Prince William Sound brought the tension between our national identification with wilderness and our national need for further natural resource exploitation into sharp focus. In the aftermath of the spill, a legislative deadlock was passed and the Oil Pollution Act of 1990 was passed. The Valdez accident had longer-term consequences as well, most prominent of which is related to the ongoing debate over whether to open up the coastal plain in the Arctic National Wildlife Refuge to further development.