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A survey of experts in the application of natural attenuation was conducted to better understand how monitored natural attenuation (MNA) is being applied at chlorinated solvent sites. Thirty-four

Sections 7 and 8 summarize the evaluation in terms of research and development directions and broad goals.Section 9 provides the references for the report.Finally, the appendices provide supplemental information and mathematical derivations to support Sections 4 and 6. The appendices are intended to provide sufficient detail to allow interested readers to better follow and replicate the evaluation and to facilitate technical review and discussion.The process of systematically disassembling and then reassembling a "contaminant plume" -in terms of loading and attenuation capacity -provided useful insights and promising directions to specifically improve implementation of natural attenuation, and generally improve environmental management and legacy management decision-making. source zone aqueous concentration at time zero, mass/volume C (x,y,z,t) concentration at a specific target location and specified time, mass/volume LIST OF TABLES LIST OF CASE STUDIESCase LIST OF ACRONYMS KEY DEFINITIONS Enhancement, Enhanced AttenuationAn enhancement is any type of intervention in a contaminated system that decreases contaminant loading or increases the magnitude of attenuation by natural processes beyond that which occurs without intervention. Enhanced attenuation is the result of applying an enhancement that sustainably manipulates a natural attenuation process leading to an overall reduction in mass flux of contaminants. Integrated Mass Flux (iMF), Loading, DischargeThe integrated mass flux is the total quantity of a migrating substance that moves through a planar transect that is within the system of interest and oriented perpendicular to the direction of movement. If the transect is at the entry point to the system the integrated mass flux is the loading. If the transect is at the exit point from the system, the integrated mass flux is the discharge. Note that these terms have units of mass per time (e.g., Kg/yr, g/day or the like) and they represent an extension of the traditional engineering definition of flux (e.g., Kg/yr/m 2 ) in which the transect area is accounted for to allow mass balance calculation of plume or system scale behavior.Monitored Natural Attenuation "'Monitored natural attenuation' …refers to the reliance on natural attenuation processes (within the context of a carefully controlled and monitored clean-up approach) to achieve sitespecific remedial objectives within a time frame that is reasonable compared to that offered by other more active methods. The 'natural attenuation processes' that are at work in such a remediation approach include a variety of physical, chemical, or biological processes that, under favorable conditions, act without human intervention to reduce mass, toxicity, mobility, volume, or concentration of contaminants in soil or groundwater." (EPA, 1999; pg. 3) Attenuation Capacity (A c )The attenuation capacity is the general term that describes the amount of a contaminant that can be assimilated and attenuated within an identified subsurface system volume. It is the compos...

Monitored natural attenuation (MNA), while a remedy of choice for many sites, can be challenging when the contaminants are chlorinated solvents. Even with many high-quality technical guidance references available, there continue to be challenges implementing MNA at some chlorinated solvent sites. The U.S. Department of Energy, as one organization facing such challenges, is leading a project that will incorporate developing concepts and tools into the existing toolbox for selecting and implementing MNA as a remediation option at sites with chlorinated solvent contamination. The structure and goals of this project were introduced in an article in the Winter 2004 issue of Remediation . This article is a summary of the three technical areas being developed through the project: mass balance, enhanced attenuation, and characterization and monitoring supporting the first two areas. These topics will be documented in separate reports available from the U.S. Department of Energy Office of Scientific and Technical Information at www.osti.gov.

This paper presents a historical background on technology transfer policy and programs, and their baseline measurement and evaluation in the U.S. Department of Energy (DOE)for the years 1981 through 1992. Specifically, an overview of Departmental research and development (R &D) laboratories briefly highlights the potential return on investment that could be gained through scientific investigation, R&D, and technology application. A historical description of federal technology transfer highlights the enabling legislation. Additionally, a discussion and summary of a 1985 Federal Laboratory Consortium (FLC) study provides a baseline assessment of technology transfer activities within DOE in the mid-1980s. The authors then discuss the findings presented