SUMMARY OF THE REMEDIATION TECHNOLOGIES DEVELOPMENT FORUM
PERMEABLE REACTIVE BARRIERS ACTION TEAM
STEERING COMMITTEE CONFERENCE CALL

3:00 p.m.-4:30 p.m.
December 20, 2001

On Thursday, December 20, 2001, the following members of the Remediation Technologies Development Forum's (RTDF's) Permeable Reactive Barriers (PRB) Action Team met in a conference call:

Bob Puls, U.S. Environmental Protection Agency (EPA) (Action Team Co-chair)
Liyuan Liang, Oak Ridge National Laboratory
Bruce Sass, Batelle
Tim Sivavec, General Electric Corporate Remediation

Also participating in the call was Danielle Sass from Eastern Research Group, Inc. (ERG).

THE STRATEGIC ENVIRONMENTAL RESEARCH AND DEVELOPMENT PROGRAM (SERDP) PROPOSAL

The RTDF PRB Steering Committee plans to initiate a monitoring project to assess PRB performance. The group is in the process of outlining the project's scope and identifying funding sources. SERDP, which has been identified as a potential funding source, recently issued a call for proposals titled Diagnostic Procedures To Evaluate Remediation Performance at Chlorinated Solvent Contaminated Sites. Pre-proposals are due on January 10, 2002; the RTDF Steering Committee plans to submit one. Prior to the conference call, Tim Sivavec distributed an outline for the pre-proposal. This was the subject of the call's discussion. Topics discussed included:

• Site selection. Sivavec noted that the majority of the work listed in the pre-proposal will take place in the field. He recommended listing a range of PRB sites that serve as strong candidates for field study. Call participants agreed that a Department of Defense site (e.g., Moffett Federal Airfield, Denver Federal Center) should be listed, but that other sites (e.g., the Y12 site, the Elizabeth City site, the Somersworth Sanitary Landfill) might be suitable candidates as well. Bob Puls agreed to collect additional information about a site in Fort Worth, Texas, to determine whether this site should be added to the list of possibilities. Sivavec noted that a range of hydrogeologic settings could be evaluated if more than one site is included in the RTDF monitoring project.



• Source zone versus dissolved-phase plumes. Sivavec noted that the RTDF plans to assess PRBs' impact on dissolved-phase plumes. SERDP has expressed interest, however, in addressing source zone areas. Sivavec agreed to include the following sentence in the pre-proposal: "Although the monitoring techniques proposed by the RTDF team will be used to evaluate dissolved-phase plumes, the techniques could have a broader application and be used to assess source zone areas."



• Commercialization of monitoring tools. Sivavec said that commercialization of inexpensive monitoring tools should be the end goal of the RTDF monitoring project. To achieve this goal, it might be necessary to work with vendors. Sivavec suggested using the following approach: (1) measure a variety of parameters, (2) identify a couple of parameters that serve as strong indicators of PRB performance, (3) work with vendors to package an inexpensive device that measures the selected parameters. In order to be successful, Sivavec stressed, monitoring tools must be inexpensive and easy to deploy.



• Measuring reducible compounds. Bruce Sass proposed developing a sensor that could be used to measure changes in iron's reductive capability. He suggested creating a probe that meters out a benign reducible compound; this could be used to measure the electroactivity of iron. Conference call participants were enthusiastic about this idea. Sivavec suggested developing a hydrogen sensor. Such a tool could be used, he said, to determine the correlation between hydrogen reduction rates and those associated with specific contaminants



• Flow sensors. Sivavec said that he needs help drafting the portion of the pre-proposal that addresses flow sensors. Ideally, he said, there will be a couple of paragraphs that describe currently available flow measurement techniques, as well as a description of the work that the RTDF team proposes. Liyuan Liang agreed to gather information from one of her colleagues and to forward it to Sivavec. Sass said that he would do the same, noting that Batelle's Neeraj Gupta would probably be able to assist in the effort. Sivavec said that he must receive the information soon, if possible before January 2, 2002.



• Project duration. Sivavec said that he believes the RTDF monitoring project will take about 3 years to complete. Call participants agreed that this was a reasonable time frame, noting that the project will consist of several steps: (1) testing a variety of currently available monitoring tools, (2) benchmarking efforts, and (3) tool development and honing efforts.



• Description of team members' capabilities. Sivavec said that he must include information about the RTDF team's capabilities. A principal investigator must be identified, he said, noting that a full C.V. will be submitted for this person. (Puls is willing to be the principal investigator if no one else steps forth.) For each other person on the team, a simple paragraph will suffice. Each Steering Committee member should send Sivavec a paragraph on his or her relevant experience and capabilities. This should be submitted before January 2, 2002.



• Next conference call. ERG will set up the next conference call for January 2, 2002.