Environmental Restoration (ER) Program Area 

The objective of this Statement of Need (SON) was to develop methodologies that can improve our ability to accurately measure, quantify, and/or enhance natural abiotic transformations of contaminants in groundwater, including those in transition zones such as the capillary fringe and deep vadose zone. While some of these abiotic transformation pathways have been studied in detail, their quantifiable impact on contaminant attenuation is still not clear, and it is also not clear whether these transformations can be effectively manipulated or enhanced in situ. Therefore, it is of paramount importance to develop and demonstrate methods to measure these processes and to enhance the natural attenuation capacity by optimizing abiotic reactions. Specifically, the goal was to address the following objectives:

  • Develop methodologies that estimate the contribution and impact of productive abiotic transformation processes on contaminant fate, transport, and toxicity under intrinsic or enhanced conditions.
  • Determine requirements for in situ enhancement of abiotic processes considering biogeochemical conditions, substrates or reactive minerals (i.e., magnetite and iron sulfides), assessing both when it is valuable to enhance abiotic processes and ultimately how to enhance these processes in a cost effective way.
  • Determine and manage short- and long-term uncertainties and risks associated with processes that can be realistically enhanced.

The projects listed below were selected to address the objectives of this SON. Additional information on individual projects can be found by clicking the project title.

    • Lead Investigator: Dr. Pei Chiu, University of Delaware

    • Lead Investigator: Dr. William Arnold, University of Minnesota

    • Lead Investigator: Dr. Jim Szecsody, Pacific Northwest National Laboratory

    • Lead Investigator: Dr. Paul Tratnyek, Oregon Health & Science University

    • Lead Investigator: Dr. Richard Johnson, Oregon Health & Science University

    • Lead Investigator: Dr. David Freedman, Clemson University

    • Lead Investigator: Dr. Tomasz Kuder, University of Oklahoma

Research in this area should lead to improved conceptual site models, by accounting for both biotic and abiotic attenuation processes, thereby providing better and more cost-effective protection of human health and the environment. Further, low-cost enhancements to ongoing natural attenuation processes may allow greater use of passive site management. Such enhancements would typically have low capital costs, minimal ongoing operational and monitoring costs, and be capable of providing long-term protection over large areas if necessary. The information developed under this SON is needed to: (1) obtain regulatory and other stakeholder concurrence that natural or enhanced attenuation is a viable, protective long-term remedial option; (2) support cost-benefit analyses of different methods for enhancing attenuation at a given site, if needed; and (3) account for fortuitous natural or enhanced attenuation abiotic processes.