Using Oil Spill Dispersants On The Sea

While major oil spills are rare, oil slicks can have disastrous environmental and economic consequences. This book summarizes research on the use of chemical dispersants: their effectiveness and limitations and the results of using them in different spill situations. Based on laboratory and field research as well as on actual case histories, this book contains a clear-cut set of recommendations for action, planning, and research. Of special interest is the chapter on the biological effects of oil itself and of oil treated with chemical dispersants.

Whether the result of an oil well blowout, vessel collision or grounding, leaking pipeline, or other incident at sea, each marine oil spill will present unique circumstances and challenges. The oil type and properties, location, time of year, duration of spill, water depth, environmental conditions, affected biomes, potential human community impact, and available resources may vary significantly. Also, each spill may be governed by policy guidelines, such as those set forth in the National Response Plan, Regional Response Plans, or Area Contingency Plans. To respond effectively to the specific conditions presented during an oil spill, spill responders have used a variety of response optionsâ€"including mechanical recovery of oil using skimmers and booms, in situ burning of oil, monitored natural attenuation of oil, and dispersion of oil by chemical dispersants. Because each response method has advantages and disadvantages, it is important to understand specific scenarios where a net benefit may be achieved by using a particular tool or combination of tools. This report builds on two previous National Research Council reports on dispersant use to provide a current understanding of the state of science and to inform future marine oil spill response operations. The response to the 2010 Deepwater Horizon spill included an unprecedented use of dispersants via both surface application and subsea injection. The magnitude of the spill stimulated interest and funding for research on oil spill response, and dispersant use in particular. This study assesses the effects and efficacy of dispersants as an oil spill response tool and evaluates trade-offs associated with dispersant use.

Whether the result of an oil well blowout, vessel collision or grounding, leaking pipeline, or other incident at sea, each marine oil spill will present unique circumstances and challenges. The oil type and properties, location, time of year, duration of spill, water depth, environmental conditions, affected biomes, potential human community impact, and available resources may vary significantly. Also, each spill may be governed by policy guidelines, such as those set forth in the National Response Plan, Regional Response Plans, or Area Contingency Plans. To respond effectively to the specific conditions presented during an oil spill, spill responders have used a variety of response optionsâ€"including mechanical recovery of oil using skimmers and booms, in situ burning of oil, monitored natural attenuation of oil, and dispersion of oil by chemical dispersants. Because each response method has advantages and disadvantages, it is important to understand specific scenarios where a net benefit may be achieved by using a particular tool or combination of tools. This report builds on two previous National Research Council reports on dispersant use to provide a current understanding of the state of science and to inform future marine oil spill response operations. The response to the 2010 Deepwater Horizon spill included an unprecedented use of dispersants via both surface application and subsea injection. The magnitude of the spill stimulated interest and funding for research on oil spill response, and dispersant use in particular. This study assesses the effects and efficacy of dispersants as an oil spill response tool and evaluates trade-offs associated with dispersant use.

Approximately 3 million gallons of oil or refined petroleum products are spilled into U.S. waters every year. Oil dispersants (chemical agents such as surfactants, solvents, and other compounds) are used to reduce the effect of oil spills by changing the chemical and physical properties of the oil. By enhancing the amount of oil that physically mixes into the water, dispersants can reduce the potential that a surface slick will contaminate shoreline habitats. Although called for in the Oil Pollution Act of 1990 as a tool for minimizing the impact of oil spills, the use of chemical dispersants has long been controversial. This book reviews the adequacy of existing information and ongoing research regarding the effectiveness of dispersants as an oil spill response technique, as well as the effect of dispersed oil on marine and coastal ecosystems. Oil Spill Dispersants also includes recommended steps for policy makers faced with making hard choices regarding the use of dispersants as part of spill contingency planning efforts or during actual spills.

Oil Spill Dispersants: Mechanisms of Action and Laboratory Tests provides a comprehensive summary of current information available regarding the general formulation of commercial dispersants and their function to lower oil-water interfacial tension. The book considers how chemical dispersants work for oil spills, the properties and chemistry of oils (including weathering state), the variables that affect dispersant performance, and the relationships between laboratory methods and field situations. The book also considers the strengths and limitations of specific laboratory tests, including brief discussions of the applicability of results for estimating dispersant performance in field trials or conditions encountered during real spill events. Laboratory tests are separated into four groups: tank tests, shake/flask tests, interfacial surface tension tests, and flume tests. Rapid-screen field tests are considered as a separate group. Recommendations for improvements in future laboratory testing are offered as well. Oil Spill Dispersants will be useful for regulators evaluating dispersant agents, field personnel involved with using dispersants, laboratory scientists studying performance and behavior of oil and dispersants, and managers responsible for designing studies related to the treatment of oil slicks with dispersants.

"The first priority when responding to an oil spill is the physical recovery of the oil from the sea. In some circumstances, however, the chemical dispersal of oil may offer certain environmental advantages in spite of the obvious drawback of driving a noxious substance such as oil into the water column. At present, decision-makers are faced with a dilemma. On the one hand, a dispersant operation must be undertaken as soon as possible after a spill occurs in order to achieve maximum effectiveness; on the other hand, the decision to permit the operation can be time-consuming due to the large number of environmental and technical factors that must be considered. The present guide has been designed to simplify the decision-making process for spills in the Southern Beaufort Sea by analysing in advance as many as possible of the important considerations and presenting the results in a form that will allow decisions to be made quickly. In addition, the guide has been reviewed by regulatory agencies so that obtaining their approval in an actual incident will be carried out more easily. In the event of a marine oil spill in the Canadian Southern Beaufort Sea the dispersant decision can be resolved into three questions: i) Is the spilled oil of a dispersible type? ii) Can an effective dispersant operation be mounted with the available equipment and material? iii) Will the use of dispersants clearly reduce the overall environmental impact of the oil spill? If the answer to all the above questions is "yes" then the use of dispersants is indicated and the On Scene Commander can proceed with a dispersant countermeasure operation after having obtained regulatory approval. This dispersant guide integrates the effects of these variables into a dispersant decision using a step-by-step approach. By working through the various steps in the guide, one can assemble and document the pieces of information that influence the dispersant use decision. ... (Au)"--ASTIS [online] database.