INDEPENDENT TECHNICAL REVIEW OF THE FOCUSED FEASIBILITY STUDY AND PROPOSED PLAN FOR DESIGNATED SOLID WASTE MANAGEMENT UNITS CONTRIBUTING TO THE SOUTHWEST GROUNDWATER PLUME AT THE PADUCAH GASEOUS DIFFUSION PLANT

The U. S. Department of Energy (DOE) is currently developing a Proposed Plan (PP) for remediation of designated sources of chlorinated solvents that contribute contamination to the Southwest (SW) Groundwater Plume at the Paducah Gaseous Diffusion Plant (PGDP), in Paducah, KY. The principal contaminants in the SW Plume are trichloroethene (TCE) and other volatile organic compounds (VOCs); these industrial solvents were used and disposed in various facilities and locations at PGDP. In the SW plume area, residual TCE sources are primarily in the fine-grained sediments of the Upper Continental Recharge System (UCRS), a partially saturated zone that delivers contaminants downward into the coarse-grained Regional Gravel Aquifer (RGA). The RGA serves as the significant lateral groundwater transport pathway for the plume. In the SW Plume area, the four main contributing TCE source units are: (1) Solid Waste Management Unit (SWMU) 1 / Oil Landfarm; (2) C-720 Building TCE Northeast Spill Site (SWMU 211A); (3) C-720 Building TCE Southeast Spill Site (SWMU 211B); and (4) C-747 Contaminated Burial Yard (SWMU 4). The PP presents the Preferred Alternatives for remediation of VOCs in the UCRS at the Oil Landfarm and the C-720 Building spill sites. The basis for the PP is documented in a Focused Feasibility Study (FFS) (DOE, 2011) and a Site Investigation Report (SI) (DOE, 2007). The SW plume is currently within the boundaries of PGDP (i.e., does not extend off-site). Nonetheless, reasonable mitigation of the multiple contaminant sources contributing to the SW plume is one of the necessary components identified in the PGDP End State Vision (DOE, 2005). Because of the importance of the proposed actions DOE assembled an Independent Technical Review (ITR) team to provide input and assistance in finalizing the PP

Scientific Opportunities for Monitoring at Environmental Remediation Sites (SOMERS): Integrated Systems-Based Approaches to Monitoring

Through an inter-disciplinary effort, DOE is addressing a need to advance monitoring approaches from sole reliance on cost- and labor-intensive point-source monitoring to integrated systems-based approaches such as flux-based approaches and the use of early indicator parameters. Key objectives include identifying current scientific, technical and implementation opportunities and challenges, prioritizing science and technology strategies to meet current needs within the DOE complex for the most challenging environments, and developing an integrated and risk-informed monitoring framework

Scientific Opportunities for Monitoring of Environmental Remediation Sites (SOMERS) - 12224

ABSTRACT The US Department of Energy (DOE) is responsible for risk reduction and cleanup of its nuclear weapons complex. DOE maintains the largest cleanup program in the world, currently spanning over a million acres in 13 states. The inventory of contaminated materials includes 90 million gallons of radioactive waste, 6.4 trillion liters of groundwater, and 40 million cubic meters of soil and debris. It is not feasible to completely restore many sites to predisposal conditions. Any contamination left in place will require monitoring, engineering controls and/or land use restrictions to protect human health and environment. Research and development efforts to date have focused on improving characterization and remediation. Yet, monitoring will result in the largest life-cycle costs and will be critical to improving performance and protection. Through an inter-disciplinary effort, DOE is addressing a need to advance monitoring approaches from sole reliance on cost-and labor-intensive point-source monitoring to integrated systems-based approaches such as flux-based approaches and the use of early indicator parameters. Key objectives include identifying current scientific, technical and implementation opportunities and challenges, prioritizing science and technology strategies to meet current needs within the DOE complex for the most challenging environments, and developing an integrated and risk-informed monitoring framework

A Pre-Landing Assessment of Regolith Properties at the InSight Landing Site

This article discusses relevant physical properties of the regolith at the Mars InSight landing site as understood prior to landing of the spacecraft. InSight will land in the northern lowland plains of Mars, close to the equator, where the regolith is estimated to be ≥3--5 m thick. These investigations of physical properties have relied on data collected from Mars orbital measurements, previously collected lander and rover data, results of studies of data and samples from Apollo lunar missions, laboratory measurements on regolith simulants, and theoretical studies. The investigations include changes in properties with depth and temperature. Mechanical properties investigated include density, grain-size distribution, cohesion, and angle of internal friction. Thermophysical properties include thermal inertia, surface emissivity and albedo, thermal conductivity and diffusivity, and specific heat. Regolith elastic properties not only include parameters that control seismic wave velocities in the immediate vicinity of the Insight lander but also coupling of the lander and other potential noise sources to the InSight broadband seismometer. The related properties include Poisson’s ratio, P- and S-wave velocities, Young’s modulus, and seismic attenuation. Finally, mass diffusivity was investigated to estimate gas movements in the regolith driven by atmospheric pressure changes. Physical properties presented here are all to some degree speculative. However, they form a basis for interpretation of the early data to be returned from the InSight mission.Additional co-authors: Nick Teanby and Sharon Keda

Demonstration of innovative monitoring technologies at the Savannah River Integrated Demonstration Site

The Department of Energy`s Office of Technology Development initiated an Integrated Demonstration Program at the Savannah River Site in 1989. The objective of this program is to develop, demonstrate, and evaluate innovative technologies that can improve present-day environmental restoration methods. The Integrated Demonstration Program at SRS is entitled ``Cleanup of Organics in Soils and Groundwater at Non-Arid Sites.`` New technologies in the areas of drilling, characterization, monitoring, and remediation are being demonstrated and evaluated for their technical performance and cost effectiveness in comparison with baseline technologies. Present site characterization and monitoring methods are costly, time-consuming, overly invasive, and often imprecise. Better technologies are required to accurately describe the subsurface geophysical and geochemical features of a site and the nature and extent of contamination. More efficient, nonintrusive characterization and monitoring techniques are necessary for understanding and predicting subsurface transport. More reliable procedures are also needed for interpreting monitoring and characterization data. Site characterization and monitoring are key elements in preventing, identifying, and restoring contaminated sites. The remediation of a site cannot be determined without characterization data, and monitoring may be required for 30 years after site closure

INDEPENDENT TECHNICAL REVIEW OF THE BUILDING 100 PLUME, FORMER DOE PINELLAS SITE (YOUNG - RAINEY STAR CENTER), LARGO, FLORIDA

Contaminated groundwater associated with Building 100 at the Young-Rainey Science, Technology, and Research Center, formerly the DOE Pinellas plant, is the primary remedial challenge that remains to be addressed at the site. Currently, Building 100 is an active industrial facility that is now owned and operated by the Pinellas county government. Groundwater samples collected from monitoring wells recently installed near the southern boundary of the site suggest that contaminated groundwater has migrated off the plant site. In response to the challenges presented by the Building 100 plume, the Office of Legacy Management (LM) requested assistance from the DOE Office of Groundwater and Soil Remediation (EM-32) to provide a review team to make technical recommendations so that they can efficiently and effectively address characterization and remediation of the plume. The review team was unanimous in the conclusion that a dynamic strategy that combines a phased implementation of direct push samplers, sensors, and tools can be used to better delineate the extent of contamination, control plume migration, and rapidly remediate the contaminated groundwater at the site. The initial efforts of the team focused on reviewing the site history and data, organizing the information into a conceptual model, identifying appropriate technologies, and recommending an integrated strategy. The current groundwater data from the site indicate a two-lobed plume extending to the east and south. To the east vinyl chloride is the primary contaminant of concern, to the south, vinyl chloride and cis1, 2-DCE are the primary contaminants. The limited data that are available suggest that reductive dechlorination of the TCE is already occurring but is not sufficient to prevent offsite migration of low concentrations of TCE daughter products. The team recommends that DOE pursue a strategy that builds on the natural cleansing capacity of the subsurface with reductive methods including biostimulation and/or bioaugmentation to provide a sustainable remediation system within the flow path of the plume. Additional data will be required to implement this approach and will include: (1) Better delineation of the nature and extent of contamination; (2) Demonstration the plume is currently stable or shrinking; and (3) Demonstration the full reductive dechlorination is occurring. The technical team recommends that DOE use a phased approach to identify residual contamination and to provide rapid installation of remedies. Matrices of characterization and remediation sensors, technologies, and tools were developed by the team in order to match the specific conditions and requirements of the site. The team provides a specific example of remedy that includes the incorporation of a dynamic characterization strategy moving from minimally invasive to more aggressive field techniques, the consideration of multiple complementary remediation approaches based on a spatiotemporally phased approach keyed to the different demands of different parts of the plume, and the integration and sequencing of the characterization and remediation activities