Experiences in dispersant treatment of experimental oil spills

in Norway, mechanical recovery has traditionally been the preferred oil spill response technique for the past decades. More recently, the Norwegian Pollution Control Authority (SFT) has opened the door to the consideration of dispersant use in certain oil spill situations. The responsibility for planning and decision for use/non-use of dispersants lies with the oil industry/enterprise itself; their decisions are subject to review and approval by SFT. This is in accordance with the "Principle of Internal Control" on what the Authorities focuses their regulations. The new regulations for use of dispersants in Norway requires well-documented contingency plans for refineries, oil terminals and offshore installations. This change in the attitude to the use of dispersants in Norway is a result of the recent years' progress in scientific documentation of dispersant use. Previous paper (Spill Science & Technology Bulletin 5(1) 1999 63) gives an overview of the methodologies developed for oil weathering and dispersibility studies in the laboratory forming the basis for the development of the SINTEF Oil Weathering Model, which has been extensively validated in the field. This paper gives a summary of the main findings from recent years' dispersant field trials in the North Sea. This work forms a basis for building up an operational and effective dispersant response for specific Norwegian coastal and offshore locations/regions. Data generated from the experimental field trials have been invaluable for validation and development of numerical models for fate and response assessment of oil spills. Examples in using the quantitative model tool "Oil Spill Contingency and Response" (OSCAR) in contingency planning and Net Environmental Benefit Analyses (NEBA) of oil spill scenarios are given. (C) 2002 Elsevier Science Ltd. All rights reserved.