APPLYING OHMSETT DATA TO SPILL CONTINGENCY PLANS1

Abstract

ABSTRACT This report describes a simple approach for using skimmer test data from the Oil and Hazardous Materials Simulated Environmental Test Tank (OHMSETT) to estimate and project performance in oil spill contingency planning. Example calculations tables are used to illustrate how a planner may choose to use test tank data. The data presented in this report are based on the several million gallons of test oil distributed to skimmers during OHMSETT tests since July 1974. A planner may have skimmers in his inventory that have been tested at OHMSETT but not rigorously tested and documented in actual spills. The planner thus is forced to use the skimmer manufacturer's rated data, thus incorporating in contingency plans an overly optimistic projected oil spill cleanup capacity. The use of OHMSETT test data can provide a lower bound estimate of the expected performance. Using the two projections together may produce a worst and a best case for the planner. These data can be used to quantify the need for backup skimmers and especially the management, transfer, and on-scene storage of the collected fluids. Dependent and independent variable measurements are discussed. Control of the independent variables is presented so that the planner may estimate the real spill performance. Throughput efficiency test data can be used to predict the number of passes a skimmer should make over a floating patch of spilled oil. Recovery efficiency test data are used to predict the quantity of oil and water that would be collected and the resulting storage needs on scene. Oil recovery rate test data are used to predict the actual quantities of oil to be collected over a period of time. Independent variables in the test tank such as oil slick thickness can become dependent variables at the spill scene, as a function of weather, oil characteristics, or the response deployment time of the planner. A sample scenario is presented involving a real skimmer. (There is no intent to compare one skimmer to another.) It is left to the planner to use this rationale to investigate his own inventory of specific skimmers and to use the existing published test data to his best advantage.