USE OF NATURAL OIL SEEPS FOR EVALUATION OF DISPERSANT APPLICATION AND MONITORING TECHNIQUES

Abstract

ABSTRACT The natural oil seeps off Coal Oil Point (Santa Barbara), California, release an estimated 100–150 bbl of oil per day to the marine environment. This project proposed to conduct a series of dispersant trials using these seeps to intercalibrate NOAA's Scientific Monitoring of Advanced Response Technologies (SMART) UV/Fluorescence-based protocols with finite measurements of dissolved aromatics and dispersed oil droplets in the water column and to evaluate a unique oil-boomldispersant-application technology (NeatSweep). Following an elaborate and lengthy permitting process including cooperation from multiple regulatory agencies and organizations, laboratory tests indicated that although fresh produced oil from nearby Platform Holly could be treated (>70% effectiveness), dispersing the weathered 11° API gravity seep oil was totally ineffective (0%). Limited field tests then verified the laboratory findings that the seep oil could not even be dispersed with Corexit 9500, a commonly used dispersant for heavily weathered and viscous oils. Lacking reasonable alternatives (including the use of intentional spills), the project was halted before full-scale field implementation. This paper documents the development of the research plan, the steps required to obtain the necessary permits, and the results from the limited laboratory and field tests that were completed. The planning and permitting efforts for this project are provided so that others with similar needs or goals might benefit. A brief discussion is provided on the limitations of using natural seep oils for spill response research and on the difficulties with spill-of-opportunity research during actual spill events. The importance of controlled experimental discharges of oil is discussed along with the pros and cons of such deliberate spills.