ABSTRACT
Four in situ burning sites that varied widely in the physical setting, oil type, timing of the burn, and post-burn treatment were assessed 0.5–1.5 years post-burn: two condensate spills in intertidal marshes at Mosquito Bay, LA in April 2001 and near Sabine Lake, LA in February 2000; crude oil spill in a ponded wetland in Minnesota in July 2000; and a spill of diesel in a salt flat/wetland north of Great Salt Lake, UT in January 2000. When used quickly after a release, burning is most effective at reducing damage to vegetation and the areal extent of impact. Where crude oil was burned within hours after the release at the Minnesota site, the impact area was restricted to 3 acres. In contrast, the diesel in the Utah spill spread over 38 acres within 3 days. The window of opportunity for in situ burning to be an effective means of oil removal can be days to months, depending on the spill conditions. The condensate spill at Mosquito Bay site was effectively burned 6–7 days after the release was reported. For spills with snow and ice cover, burning may still be effective months later. In fact, it may be necessary to consider additional burns during thaw periods and during the final thaw. Burning will not reduce the toxic effects of the oil that occurred prior to the burn. It can, however, be very effective at reducing the extent and degree of impacts by quickly removing the remaining oil. In three of the four case studies, the area burned was significantly larger than the oiled area (up to 10 x). Healthy, green, unoiled vegetation is not always an effective fire break, particularly downwind; fires can quickly jump the kinds of fire breaks placed during spill emergencies in wetlands (e.g., vegetation laid down by the passage of airboats).
