Environmental advisor, Shell Oil Co., Houston, TX
Pages: 21 Published: Jan 1989
Although the National Contingency Plan states that the Federal On-Scene Coordinator (OSC) may authorize the use of dispersants on an oil spill, such authorization is not automatic. In practice, the applicant for permission to use dispersants must submit a plan which then will be considered by the OSC and others involved in the approval process. This plan generally must indicate not only that dispersant use is desirable as a means of mitigating the spill but also must show why use would result in lower environmental impact than if dispersants were not used.
Some parts of a dispersant use plan are time-consuming to prepare and require acquisition of large amounts of information. Fortunately, the most time-consuming parts can be prepared well in advance of any spill. If these parts are prepared in advance, decisions regarding dispersant use can be made in a timely fashion at the time of a spill.
The components of a dispersant use plan should include the following: 1. Spill specific information such as how much of what oil was spilled, when did it occur, wind and sea conditions, and expected oil spill trajectories. 2. Information on resources available for dispersant application such as dispersant stock-piles that may be used, properties of these dispersants, application equipment, and information on application and monitoring methods. This information can best be gathered well in advance of any spill event. 3. Information on environmental impacts, including the comparative impacts of dispersed oil versus untreated oil. This information should be prepared and available in a form that will enable ready assessment, at the time of a spill, of the trade-offs which must be considered. It should be possible to identify well in advance of a spill those areas in which dispersant use should be considered and those in which use might not be favored. 4. A guide or system for decision making; this guide will show how the above information is used in developing the on-scene decision for or against dispersant use. The decision making system should be agreed upon well in advance of any spill. 5. Recommendations regarding dispersant use on the specific spill incident and justification for the recommendations.
Use of this planning method will expedite decision making at the time of a spill, will lead to more rational and logical dispersant use decisions, and will enable the decision maker to document his decision.
dispersants, planning, decision diagrams, decision trees, monitoring, guidelines, trade-offs
Paper ID: STP18656S