Remediating and Monitoring White Phosphorus Contamination at Eagle River Flats (Operable Unit C), Fort Richardson, Alaska

Abstract

Abstract : This is the eleventh annual contract report prepared by researchers from CRREL and other Federal agencies for U.S. Army Engineer District, Alaska, and U.S. Army Alaska, Public Works, describing the results of research, monitoring, and remediation efforts addressing the white phosphorus contamination in Eagle River Flats, an 865-ha estuarine salt marsh on Fort Richardson, Alaska. Fort Richardson is on the National Priority List, and Eagle River Flats is designated Operable Unit C (OU-C) under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). This year marks the second of a planned five-year remediation effort in Eagle River Flats. Pond pumping, using six remote-controlled pumps to temporarily drain contaminated ponds within several areas of Eagle River Flats, was conducted again this year. The pumps kept the ponds drained for an extended period during the summer, allowing the pond bottom sediments to dry and the white phosphorus to sublime and oxidize. The logistics continued to be fine-tuned, leading to a more effective and efficient operation this year. The combination of a warm, dry period during the first half of the summer and the successful use of flood gates to prevent flooding tides resulted in a long and effective drying season. Sampling showed that levels of contamination continued to decline, although localized areas of contamination still exist.