Method for Attenuation of White Phosphorus Contamination in Wetlands

White phosphorus, a manufactured form of elemental phosphorus, is both toxic and persistent in saturated environments. This form of phosphorus (P4) is used by militaries worldwide as a component for obscurants, tracer rounds, and incendiary munitions. At Eagle River Flats, an estuarine salt marsh located on Fort Richardson, Alaska, white phosphorus has been directly linked through carcass analysis to the deaths of thousands of dabbling waterfowl. Particulate residue from ordnance contaminates the permanently ponded areas of Eagle River Flats, where the waterfowl sieve the soft bottom sediments for food items, picking up P4 particles in the process. Death follows within hours. Large-scale investigations into the nature, extent, and persistence of the contaminant were initiated in 1989, followed 4 years later by work on the testing and analysis of remediation methods. In 1997, a method for in situ remediation of the contaminant through low-impact pumping and draining of ponded areas to enhance natural attenuation of white phosphorus was tested. Results indicate that pond pumping is a very effective remediation technique.