In-situ burning in the marshland environment-soil temperatures

Oil spill response teams were faced with unique and difficult challenges when the oil spills of refined hydrocarbons occurred in salt marshes or similar environments. With mechanical recovery being so difficult, it was also feared that the impact of the clean up would be worse than the oil itself. It was not known what the impact of intentional burning of an oil spill in such a case would be. Many parameters had to be considered including plant species, fuel type and load, water level, soil type, and burn duration. A series of ten tests were conducted in a 6 m tank which reproduced the conditions found in marshlands and the authors exposed 80 different plant species to intentional burning of spilled diesel fuel. The plants were positioned at four different depths: -10 cm, -2 cm, 0 cm, +10 cm relative to water level. Some forty plants were equipped with thermocouples to gather data concerning soil temperatures. The burns lasted for 400 s or 1400 s. Once the results were analysed, it was found that a minimum of 2 cm of water prevented permanent damage to the plant/root system. The authors concluded that the intentional burning of spilled oil in a marshland is an acceptable alternative and less damaging than mechanical recovery. 29 refs., 4 tabs., 17 figs