For Response Planning: Predicted Environmental Contamination Resulting from Oil Leakage from Sunken Vessels

Abstract

An evaluation was made of the amounts and types of oil potentially released from sunken vessels in U.S. waters, where oil would be transported, how rapidly it would reach sensitive resources, and magnitudes of impacts on surface water and shorelines. Oil spill modeling was performed as part of a screening analysis to identify those sunken vessels of highest risk for environmental and socioeconomic impacts, with the expectation that those identified will be subject to more detailed analysis. The modeling provides estimates of the locations of oiling, as well as areas of water surface, lengths of shoreline, and volumes of water exposed above potential effects thresholds (oil thickness or concentrations). We developed regression models of the resulting indices of oil impacts as a function of spill volume, allowing for predictions of water surface area, shoreline extent, and water volume affected for any potential (partial or entire) release volume from the sunken vessel. We ran RPS-ASA's SIMAP model in probabilistic mode, i.e., long-term wind and current records were sampled at random and model runs performed for each of 200 selected spill dates and times. The model results provide a statistical description of the probabilities and potential locations and magnitudes of oil-related impacts. This consequence analysis may be used to assign priorities for potential salvage of sunken vessels based on relative risk. The resultant analysis may be used by decision-makers to evaluate response needs, such as response equipment capacities, timing of deployment required to protect sensitive resources, and possible time windows and areas for dispersant use.