Radisson Hotel Universal Orlando
Orlando, Florida
June 12, 2001

On Tuesday, June 12, 2001, the following members of the Remediation Technologies Development Forum's (RTDF's) Permeable Reactive Barriers (PRB) Action Team Steering Committee met in Florida:

Bob Puls, U.S. Environmental Protection Agency (EPA)
John Vidumsky, DuPont
Robert Gillham, University of Waterloo
Richard Landis, DuPont
Stan Morrison, MacTec-ERS
Tim Sivavec, General Electric
Richard Steimle, EPA
Matthew Turner, New Jersey Department of Environmental Protection
Stephen White, U.S. Army Corps of Engineers

Also present were Volker Birke of the University of Applied Sciences; Grant Hocking of Golder Sierra LLC; Edward Seger of DuPont; Leah Matheson of MSE Technology Applications, Inc.; Peter Kjeldsen of the Technical University of Denmark; Torge Tuennermeier of the Federal Institute for Materials Research and Testing; Markus Ebert of University of Kiel; David Smyth of the University of Waterloo; Narendra Dave of the Louisiana Department of Environmental Quality; Rick Wilkin of EPA; Carolyn Perroni of Environmental Management Support, Inc.; and Jason Dubow of Eastern Research Group, Inc.

PRB SITE PROFILES

Bob Puls said that information about PRB sites is presented in site profiles that appear on the RTDF Web site. (See www.rtdf.org.) The Web site is very popular, he said, and many of those who visit it do so to view the PRB site profiles. The site has a search feature: users can search site profiles by geology, hydrology, contaminant type, or construction type. Carolyn Perroni said that efforts are underway to improve the site profile database. She noted these upcoming improvements:

• Existing site profiles will be updated. Perroni said that only a few of the existing profiles have been updated so far; she asked meeting attendees to submit updates soon. When reviewing the existing profiles, she said, one should check Web links to ensure that they are up to date.
• New site profiles will be added. Perroni said that she knows of 30 sites to add to the database. She distributed a list of these, asking meeting attendees to contact her if they knew of others. (She encouraged attendees to identify sites outside the United States.) Perroni indicated that she has information on about 17 of the 30 sites, and that she will follow up with the other sites over the next few weeks.

Perroni said that information on existing or new sites can be submitted through the RTDF Web site or by sending it to Carolyn.Perroni@emsus.com. All information should be submitted by July 30, 2001. Perroni will send out e-mails to remind people of the due date.

THE PRB ACTION TEAM's ROLE

Puls and John Vidumsky said that the PRB Action Team has been in existence for several years. During that time, great strides have been made toward advancing PRB development, implementation, and acceptance. The Action Team has promoted PRB technologies by sponsoring research, performing technology transfer, and supporting training programs. In addition, Puls said, the Action Team was involved with a long-term performance monitoring study that was performed by EPA, the Department of Defense, and the Department of Energy. The results of this tri-agency study will be released by the end of the year.

Puls and Vidumsky said that the PRB Action Team is at a crossroads: many of its activities have been completed, and the Steering Committee needs to identify the Action Team's path forward. The two co-chairs asked meeting attendees for suggestions on how to proceed. Attendees identified areas of research that could be explored and potential activities to pursue. The following consensus emerged from their conversation: the PRB Action Team should focus on promoting PRB technologies. At the start of the meeting, not all of the attendees agreed with this stance. In fact, some indicated discomfort with taking on the role of "marketer" and suggested keeping the Action Team's activities in the arena of research generation. It was quickly pointed out, however, that technology promotion has always been one of the Action Team's core goals. In fact, the Action Team has already been involved with an extensive training program, the purpose of which was to educate the regulatory community about the benefits of PRB technologies. Despite the fact that many regulators now understand the merits of PRBs, attendees noted, the technology is still underutilized. One attendee suggested that this was because the technology is still in the early stages of the marketing curve. Another attendee said that the technology is still regarded as high risk, and that many site owners fear going forth with PRBs because they are uncertain of the technology's efficacy. Another attendee thought that steep up-front installation costs pose a major obstacle, noting that site managers have been known to pick cheap interim measures over effective long-term remedial solutions. Other attendees suspected that the technology's lack of widespread market penetration indicates that consultants have not completely embraced PRBs. Attendees agreed that consultants play a key role in selecting remediation technologies, and that outreach efforts to this group should be intensified.

Meeting attendees brainstormed on ways to promote PRB technologies. They expressed the most interest in the following activities:

• Compile data from Elizabeth City and three or four other PRB sites that have produced favorable results. Several meeting attendees said that it would be useful to have a complete set of field chemistry data for three or four PRB sites. Attendees suggested obtaining funds to compile and disseminate the data for Elizabeth City, and if necessary, to augment monitoring activities at other successful sites to ensure that complete data sets are formed for at least three or four sites. The data should be made available, attendees said, in a document and via the Internet.
• Focus on successful case studies at the next PRB Action Team meeting, and include a free half-day training session for consultants. One attendee noted that past PRB Action Team meetings have glossed over success stories and stressed uncertainties. While it is true that researchers do not have all the answers about PRBs, he noted, all technologies suffer uncertainties. Thus, the Action Team needs to make this clear and focus on the positive aspects of PRB technology.
• Produce public relations documents. Perroni said that it might be useful to disseminate information touting the success of PRBs and the PRB Action Team's accomplishments. Attendees thought this was a good idea. Some suggested creating a document that summarizes the state of the technology. Others thought a short fact sheet would serve as a useful communication tool. Grant Hocking said that PRBs are being considered more and more often in feasibility studies—a point that should be made clear to the environmental remediation community. Perroni suggested putting together an article or press release that summarizes PRB success stories. This could be posted on the RTDF Web site, she said, and distributed to the entire PRB Action Team mailing list, Tech Direct, and other mass mailing lists. Robert Gillham also suggested publishing the article in trade magazines, such as Engineering New Record, in an effort to reach out to consultants.
• Reach out to the international community. Meeting attendees agreed that efforts should be made to establish links connecting the RTDF Web site with international groups. Puls said that it might also be useful to establish a list serve that reaches across country boundaries.
  

One attendee suggested asking someone with marketing experience to review the RTDF Web site to provide input on its navigability and usefulness. Also, some attendees talked about using a Web-based training to reach out to the consulting community. Few attendees expressed interest, however, in pursuing this latter option.

Throughout the conversation, attendees identified a number of other activities that might be useful to pursue. Although these activities were not chosen as topics for immediate followup, they are listed here for the sake of completeness.

• Obtain funding for a field project. Vidumsky said that other RTDF Action Teams (e.g., the Bioremediation Consortium) have obtained funds for demonstration projects. The PRB Action Team could do something similar, he said, if it identified a field research program that would provide answers to important questions. Groups like the Chlorine Chemistry Council, Vidumsky said, might be interested in contributing to a field effort.
• Explore hydrology and site characterization issues. A few participants asked whether there was anything the PRB Action Team could do to increase understanding about hydraulic characterization. Two suggestions were offered: (1) write a guidance document and/or (2) perform a field demonstration project to explore the issue. Vidumsky responded to these suggestions, noting that he is leery of undertaking a project that focuses solely on hydraulic characterization. It is an important issue, he acknowledged, but projects that revolve around it tend to lose focus. Some meeting attendees agreed, saying that a balance must be kept between characterization research and technology implementation. If the focus falls too heavily on the former, the latter is often lost in the process. Other meeting attendees acknowledged Vidumsky's point, but said they still believe it would be useful to produce a guidance document that addresses hydraulic characterization, design, implementation, and monitoring.
• Disseminate information about PRBs that have "failed." Some meeting attendees said that it would be useful to release information about PRBs that have failed to perform up to expectations. Information on these "failures" could provide important lessons, prevent people from repeating mistakes, and eradicate misconceptions. Attendees agreed that information about problems is useful, but were reluctant to put together a "catalog of failures," noting that no technology is successful at every site and that it would be more useful to highlight successes than to dwell on failures. In addition, some attendees made the point that the terms "success" and "failure" are subjective. The only way to determine whether a technology has succeeded at a site is to compare it to what would have been accomplished using a different technology.
• Invest in additional technology development. Vidumsky said that the PRB Action Team could sponsor efforts to develop PRBs for new applications. He advised against doing so, however, noting that several researchers and private companies are already undertaking such efforts. For example, he noted, some investigators are trying to use zero-valent iron to address contaminant sources; others have started installing PRBs in bedrock.
• Find ways to reduce costs. Attendees noted that it would be wonderful if costs associated with reactive material and monitoring could be reduced. Maybe it would be useful, one attendee suggested, to identify ways to tailor reactive materials rather than simply relying on commercially available iron products.
• Investigate the possibility of combining PRBs with natural attenuation. Puls and Gillham agreed that PRB Action Team members should talk to Bioremediation Consortium members about using PRBs and natural attenuation in a treatment train.
• Make more efforts to compare PRB technologies to other technologies. Meeting attendees noted that site managers often use cost as a driver when comparing PRB technologies to other technologies. One attendee suggested gathering cost and performance data from a suite of PRB sites and comparing these data to that which would be expected from pump-and-treat technologies. (A model for such a comparison is provided in the appendix of a Rice Program study.) Peter Kjeldsen advised including a more robust set of technologies in the comparison analysis rather than focusing solely on pump-and-treat.