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.     

The Media Politics of Oil Spills

This paper considers the ways in which news values shape the reporting of oil spills and the constraints under which media practitioners work. A series of oil spills since the late 1960s [including the Torrey Canyon (1967), the Exxon Valdez (1989), and the Sea Empress (1996)] have attracted considerable attention from the news media. The focus is upon the dynamics through which news sources, with their own particular vested interests, compete to secure representation of the issues. Media discourse on risk and the environment is, to a significant extent, a discourse dependent upon the voices of official “experts”. Environmental organizations, industry, scientists and government offer their own particular competing accounts of the “reality” of the situation. Issues concerning differential access to the news media are crucial when considering who comes to define the event. Accordingly, the article examines the strategies adopted by the various news sources involved in influencing the symbolic representation of public issues.Media practitioners are faced with great problems in interpreting and explaining these competing claims. Relatively few journalists and broadcasters have a scientific training and perhaps one of the greatest problems is that by simplifying complex scientific information one inevitably distorts it. Frequently researchers make the assumption that it is possible to demonstrate a direct causal link between news media coverage and public attitudes. However, the paper calls for great caution in interpreting “public opinion” concerning environmental issues and concludes by arguing that news media representations may more usefully be viewed as the outcome of a battle among a selective range of news sources, each seeking to provide their own definition of the public representation of the issues.     

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.     

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.     

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.     

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.     

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.     

Oil Spill Contingency and Response (OSCAR) Analysis in Support of Environmental Impact Assessment Offshore Namibia

The work reported here encompasses analyses of specific potential spill scenarios for oil exploration activity planned offshore of Namibia. The analyses are carried out with the SINTEF Oil Spill Contingency and Response (OSCAR) 3-dimensional model system. A spill scenario using 150 m³ of marine diesel demonstrates the rapidity with which such a spill will dissipate naturally, even in light winds. Vertical and horizontal mixing bring subsurface hydrocarbon concentrations to background levels within a few days. A hypothetical 10 day blowout scenario releasing 11,000 bbl per day of light crude oil is investigated in terms of the potential for delivering oil to selected bird and marine mammal areas along the Namibian coast. Worst case scenarios are selected to investigate the potential mitigating effects of planned oil spill response actions. Mechanical recovery significantly reduces, and in some cases eliminates, potential environmental consequences of these worst case scenarios. Dispersant application from fixed wing aircraft further reduces the potential surface effects. The analysis supplies an objective basis for net environmental analysis of the planned response strategies.     

Environmental Assessments in the Oil and Gas Industry

The general public, government regulators, and environmental organizations are increasingly demanding industries to reduce their environmental impacts and report progress. This in turn resulted in numerous requirements for reporting environmental data. Environmental assessments are a useful tool in gathering and documenting this data. The assessments also assist decision makers to quantify impacts of their activities and plan for appropriate mitigation measures. There are different types of environmental assessments, each having specific purpose(s) and addressing specific audience(s). This paper gives an overview of common environmental concerns associated with oil and gas industry and shares insights on types of environmental assessments that are widely used. It discusses general methodologies to define the scope, approach, measurement standards, and reporting. Potential challenges encountered in conducting these assessments in an international arena and under a wide variety of regulatory requirements are addressed. Practical approach in execution of these assessments is described here, and strategy in dealing with the challenges is presented.     

农药生产建设项目环境影响评价的探讨

分析了农药生产建设项目环境影响评价中存在的诸多问题。结合实际工作经验,就农药生产建设项目中的产业政策评价、环境影响的识别、环境风险评价、清洁生产评价和环保治理措施的确定进行了探讨。     

论区域环境规划与区域开发环境影响评价在区域开发环境管理中的作用和地位

回顾了国内外区域开发环境管理的发展历程，简要论述了区域环境规划与区域开发环境影响评价在区域开发环境管理中的作用和地位以及两者的相互关系。     

化工建设项目环境影响评价中的热点问题

分析了化工建设项目环境影响评价工作中的热点问题。指出化工生产的环境风险是可控的;环评报告书中应将环境风险的预防作为风险评价的重点,同时要积极推进责任关怀,将企业每年度外排的各种污染物的数量及削减量如实公布,让公众了解企业在预防污染方面的进步和尚存的问题。提出了精简环评报告书的途径：编写环评报告书简化本;突出环评报告书的重点,将污染预防和治理措施作为环评报告书最重要的章节之一;评价环境影响预测的准确性等。     

农药行业规划环境影响评价中的风险评价

针对专项工业规划环境影响评价中环境风险评价应用尚不成熟的现状,建立了一套专项工业规划环境风险评价方法,并将其应用到江苏省农药行业总体规划环境影响评价分析中。从环境风险角度分析行业发展方向、强度和布局的合理性,提出规划调整和行业风险管理的建议,以降低事故发生的概率和影响,保障行业的健康稳定发展。通过对江苏省农药行业规划明确的产品结构、产业组织结构、创新体系和技术发展目标等进行风险识别、分析和评价,得出生产和使用光气的定点企业、使用液氯的企业、产生硫化氢的企业的环境风险防护距离（以生产装置为起点）应至少设置为1 000,500,250 m。     

清洁过程环境影响评估模块的开发

在过程开发早期阶段考虑环境问题是实现污染预防的有效手段。将环境影响评估功能集成于过程模拟软件是一项重要的工作。以通用模拟软件ECSS—ChStar为平台,开发出环境影响评估模块。该模块可以对物质流、过程单元和总流程提供环境模拟分析,并计算过程方案的环境影响指数。     

输变电环境影响评价及竣工环保验收相关要点分析

通过输变电环境影响评价及竣工环保验收工作的实践,从输变电环境影响评价及竣工环保验收的基本概念和相关法律、法规出发,分析了输变电环境影响评价及竣工环保验收工作的要点,包括敏感目标调查、生态环境影响评价与监测、声环境评价重点、公众参与等,在此基础上论述了两者之间的相互关系,最后针对输变电环境影响评价及竣工环保验收工作更加科学化提出了建议。