Contaminant Flux and Fate in Fractured Bedrock

Dr. Charles Schaefer | CDM Smith

ER-201570-T2

Objective

The overall goal of this project is to develop and implement a short (i.e., half day) seminar that highlights recent advances in the fate and transport of chlorinated solvents in fractured bedrock, and how these advances can be used for improved management of the DoD’s fractured rock sites. DoD Remedial Project Managers (RPMs) overseeing fractured bedrock sites impacted with chlorinated ethenes will be specifically targeted, along with the regulators and contractors involved with these sites. 

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Technology Description

This project’s proposed approach is based on an innovative approach to technology transfer. Key innovative aspects to this approach include the following:

ER-201570_graphic_1
  • Surgical targeting of 6 key DoD fractured bedrock sites. By focusing on RPMs (and regulators) at 6 key DoD sites where chlorinated solvents in fractured bedrock remain a large liability, the potential beneficial impacts of technology transfer will be maximized. In addition, as application of new technologies and tools are implemented at these high-profile DoD bedrock sites (resulting from these proposed technology transfer seminars), implementation at other DoD sites will likely follow as new industry standards are set.
  • Incorporation of site-specific data into the proposed seminars. Discussing the RPM’s site during the seminar will provide value, providing the RPM and regulators (and perhaps other contractors) with added incentive to participate. More importantly, incorporating site-specific details and high priority needs will help to “bridge the gap” between the research and application, ultimately facilitating technology transfer.
  • Seminar presented by those who were involved with the fundamental science and field application (remediation and site assessment). Thus, the presentation will focus on transitioning fundamental science to practical application that can be readily utilized for improved site management by DoD RPMs.

The technologies to be presented in the seminars are all mature, having been successfully demonstrated through SERDP and ESTCP, and/or published in the peer reviewed literature. The half-day seminar will cover a range of topics related to contaminant flux in fractured bedrock, and will address areas of concern including site assessment, downgradient contaminant migration, rock matrix processes (e.g., diffusion, sorption, reaction), and the practical limits of remedial effectiveness. Topics to be covered include the following:

  • Identification of Contaminant Flux Zones in Fractures
  • DNAPL in Fractured Rock (Architecture and Impacts on Groundwater)
  • Diffusion in Rock Matrices
  • Sorption and Abiotic Reaction in Rock Matrices
  • Estimating Plume Longevity and Practical Limits of Remedial Effectiveness (via models and field testing techniques)
  • Discussion of Remedial Approaches.

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Benefits

The DoD has dozens of fractured bedrock sites impacted by chlorinated solvents. Cost effective long-term solutions are lacking at most of these sites. The technologies and technical approaches that will be presented as part of these seminars has potential to provide a plausible path forward at many of these sites.

While an attempt to determine a realistic reduction in cost that could be obtained from this technology transfer effort is nearly impossible, experience at Loring AFB suggests that costs associated with source area treatment can potentially be reduced by nearly an order of magnitude (due to addressing high contaminant flux zones only). If this benefit is only realized at one site, then the return on investment of this technology transfer effort would be quite large. (Anticipated Project Completion – 2017)

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Points of Contact

Principal Investigator

Dr. Charles Schaefer

CDM Smith

Phone: 732-590-4633

Program Manager

Environmental Restoration

SERDP and ESTCP

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