The number of hazardous waste sites across the United States has grown to approximately 217,000, with billions of cubic yards of soil, sediment, and groundwater plumes requiring remediation. Sites contaminated with recalcitrant contaminants or with complex hydrogeological features have proved to be a significant challenge to cleanup on every levelâ€"technologically, financially, legally, and sociopolitically. Like many federal agencies, the Navy is a responsible party with a large liability in hazardous waste sites. Environmental Cleanup at Navy Facilitites applies the concepts of adaptive management to complex, high-risk hazardous waste sites that are typical of the military, EPA, and other responsible parties. The report suggests ways to make forward progress at sites with recalcitrant contamination that have stalled prior to meeting cleanup goals. This encompasses more rigorous data collection and analysis, consideration of alternative treatment technologies, and comprehensive long-term stewardship.

The fiscal and technological limitations associated with cleaning up hazardous waste sites to background conditions have prompted responsible parties to turn to risk-based methods for environmental rememdiation. Environmental Cleanup at Navy Facilities reviews and critiques risk-based methods, including those developed by the U.S. Environmental Protection Agency and the American Society of Testing and Materials. These critiques lead to the identification of eleven criteria that must be part of any risk-based methodology adopted by the Navy, a responsible party with a large number of complex and heavily contaminated waste sites. January

The fiscal and technological limitations associated with cleaning up hazardous waste sites to background conditions have prompted responsible parties to turn to risk-based methods for environmental rememdiation. Environmental Cleanup at Navy Facilities reviews and critiques risk-based methods, including those developed by the U.S. Environmental Protection Agency and the American Society of Testing and Materials. These critiques lead to the identification of eleven criteria that must be part of any risk-based methodology adopted by the Navy, a responsible party with a large number of complex and heavily contaminated waste sites. January

While expected environmental cleanup costs for unneeded property arising from the 2005 BRAC round are not yet fully known, Department of Defense (DOD) data indicate that about $950 million will be needed to clean up these bases, adding to the estimated $13.2 billion total cleanup cost for the prior rounds. Although DOD's cleanup program has matured compared to prior BRAC rounds, there are still many unknowns and the cleanup estimate for the 2005 round should be considered preliminary. In fact, environmental cleanup costs are likely to increase as more intensive environmental investigations are undertaken, additional hazardous conditions are discovered, and future reuse plans are finalized. Furthermore, Congress does not have full visibility over the total cost of DOD's BRAC cleanup efforts because none of the four reports DOD prepares on various aspects of environmental cleanup present all types of costs past and future to complete cleanup at each base. Compiling a complete picture of all costs requires extracting information from multiple reports, as GAO has done to estimate the total cleanup cost for the four prior BRAC rounds. More complete and transparent cost information would assist Congress in conducting its oversight responsibilities for this multibillion dollar effort.

The goals of sediment remediation are to remove contaminated sediments from the environment, obstruct contaminant migration into the environment, and/or minimize exposure of ecological or human receptors to sediment contaminants. Contaminated sediments can be either left in place or removed, and often several cleanup techniques are used in combination or in sequence. In some situations, the best solution may be to allow natural burial and chemical weathering to permanently reduce risk. In other cases, sediments can be left in place with a low-permeability and erosion-resistant cap. In cases of relatively high risk of leaving sediments in place, dredging may be required to remove sediments from their existing environment. Once removed, the sediments may require dewatering or treatment prior to disposal, and may be disposed in upland disposal sites, in subaqueous CADs or CDFs. Innovative in situ treatment technologies are under development, some of which may provide beneficial use of the contaminated sediments as feed stock for the manufacture of Portland cement, light-weight aggregate, architectural tiles, or for low- contaminated sediments compost.