Four in situ burning sites that varied widely in thephysical setting, oil type, timing of the burn, and post-burntreatment were assessed 0.5-1.5 years post-burn: two condensatespills in intertidal marshes at Mosquito Bay, LA in April 2001and near Sabine Lake, LA in February 2000; crude oil spill in aponded wetland in Minnesota in July 2000; and a spill of dieselin a salt flat/wetland north of Great Salt Lake, UT in January2000. When used quickly after a release, burning is most effectiveat reducing damage to vegetation and the areal extent of impact.Where crude oil was burned within hours after the release at theMinnesota site, the impact area was restricted to 3 acres. Incontrast, the diesel in the Utah spill spread over 38 acres within 3days. The window of opportunity for in situ burning to be aneffective means of oil removal can be days to months, dependingon the spill conditions. The condensate spill at Mosquito Bay sitewas effectively burned 6-7 days after the release was reported.For spills with snow and ice cover, burning may still be effectivemonths later. In fact, it may be necessary to consider additionalburns during thaw periods and during the final thaw. Burningwill not reduce the toxic effects of the oil that occurred prior tothe burn. It can, however, be very effective at reducing the extentand degree of impacts by quickly removing the remaining oil. Inthree of the four case studies, the area burned was significantlylarger than the oiled area (up to 10 x). Healthy, green, unoiledvegetation is not always an effective fire break, particularlydownwind; fires can quickly jump the kinds of fire breaks placedduring spill emergencies in wetlands (e.g., vegetation laid downby the passage of airboats).
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