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

3:00 p.m.-4:30 p.m.
July 12, 1999

On Monday, July 12, 1999, the following members of the Permeable Reactive Barriers (PRB) Action Team Steering Committee met in a conference call:

Bob Puls (co-chair), U.S. Environmental Protection Agency (EPA)
Nic Korte, Oak Ridge National Laboratory (ORNL)
Liyuan Liang, ORNL
Stan Morrison, Roy F. Weston, Inc.
Timothy Sivavec, General Electric Corporate Remediation
Scott Warner, Geomatrix Consultants, Inc.
Stephen White, U.S. Army Corps of Engineers

Also present were Carolyn Perroni of Environmental Management Support, Inc. (EMS), and Christine Hartnett of Eastern Research Group, Inc. (ERG).

PRB TRAINING COURSE

Scott Warner noted that the first official PRB training course was presented in Boston, Massachusetts, in June 1999. This course, which was developed by several Steering Committee members, attracted an audience of about 180 people. Most of the attendees were local regulators (representing either federal agencies or states that are located in the Northeast) or private consultants.. About 90 percent of the attendees stayed for the entire course, Warner said, an indicator that the course's format and material can hold an audience's attention. Warner noted that audience members were encouraged to participate freely during question and answer sessions. Liyuan Liang asked for information about the kinds of questions that were asked. Warner agreed to summarize the questions and to distribute them to Steering Committee members.

Warner said that minor modifications will be made to the course materials before the August 1999 training session, which is to be held in Tacoma, Washington. After that meeting, the course will be presented in eight additional cities. In general, Warner said, the materials presented across the cities will be very similar, with one notable exception: each city will attract a different guest lunch speaker. For example, Warner said, Thomas Krug talked about the Somersworth Landfill site at the Boston meeting and Paul Tratnyek will talk about an educational CD-ROM at the Tacoma meeting. Additional guest lunch speakers will be identified for the other meeting locations in the near future.

NEXT RTDF MEETING

Conference call participants agreed that it would be useful to hold another PRB Action Team meeting. Bob Puls said that he has already talked to some Steering Committee members about potential meeting topics, and two general themes have emerged:

• Installation difficulties and challenges. Conference call participants agreed that this would be an excellent topic to cover at the meeting. Timothy Sivavec stressed that it is important for people to talk about installation problems and to understand what caused them. Failure to discuss these issues could be detrimental to the PRB technology. For example, he said, some people have been asking him about the installation problems that were encountered at the Denver Federal Facility. Some people have told him that the negative experiences at that site may unfairly brand the entire PRB technology with a bad reputation. Sivavec suggested having a site representative attend the PRB Action Team meeting to explain why problems were encountered.

• Site characterization needs. Puls said that inadequate site characterization is often cited as the root of the problem when PRBs perform suboptimally. For this reason, site characterization has been recommended as one of the major themes for discussion at the next PRB Action Team meeting. Conference call participants agreed that this would make an excellent topic for discussion.

Puls agreed to find people to speak on site characterization issues, but he asked conference call participants to help him in the effort of identifying speakers. Nic Korte and Liang agreed to find people to speak about the Kansas City site and Oak Ridge's Y-12 site, respectively. Other conference call participants agreed to find people to speak about activities at the Denver Federal Center, Shaw Air Force Base, and Travis Air Force Base.

Conference call participants talked about where and when the meeting should take place. Puls recommended having it in February 2000, saying it would be difficult to fit in a meeting before that time because of schedule conflicts. Three locations were suggested:

• Atlanta, Georgia. Warner said that the PRB training course (described above) will be offered in Atlanta on February 8 and 9, 2000. He and Liang said that attendance for the PRB Action Team meeting might be boosted if it were held in Atlanta immediately following the training course. Liang noted that some people who attend the training will likely be interested in attending the PRB Action Team meeting. Although conference call participants agreed that having two meetings in the same location would cut traveling costs for those who wanted to attend both, they generally agreed that it would be better to have some time in between the training course and the PRB Action Team meeting. (Conference call participants thought only about 20 percent of the people attending the training course would be interested in attending the Action Team meeting. Of those who would even be interested, Puls said, few would probably be able to afford to spend so many consecutive days out of the office.)

• Charleston, South Carolina. Puls recommended Charleston, South Carolina, as a location for a meeting, noting that several site owners in this area are considering installing PRBs. Some of them might be amenable to the idea of letting Action Team members conduct a field trip to their site. Because activities are so preliminary at the sites near Charleston, Puls noted, it could be very useful to have a meeting addressing site characterization issues in that area. One conference call participant, however, questioned whether South Carolina was a good choice, noting that air fares for that part of the country can be fairly high.

• Cape Canaveral, Florida. Of all of the meeting locations discussed, conference call participants expressed the most interest in having their meeting in Florida so that a field visit to Cape Canaveral could be incorporated as a component of the meeting. Stan Morrison agreed to contact representatives from the Cape Canaveral site to determine whether such a field trip would be possible during the week of February 20, 2000. He said that he would report back to Puls with his findings.

LONG-TERM PERFORMANCE

Puls said that EPA, the Department of Defense (DOD), and the Department of Energy (DOE) are performing a project to evaluate the long-term performance of PRBs. He said that each agency is evaluating a different set of sites and that the information collected will be pooled so that some general conclusions can be made. He noted that there must be good coordination between the three participating agencies to make this project a success. Liang agreed, suggesting that the people who are leading the projects get together to discuss protocol and scope of work. That way, she said, all three agencies will collect similar and comparable information. She agreed to set up a meeting at which these discussions can take place and to contact the appropriate people with the meeting's time and date. (One participant recommended August 13 as a meeting date.) Puls thanked Liang for her willingness to take charge of this action item. He also noted that good coordination will be needed throughout the project, not just at the beginning. He said that the Federal Remediation Technologies Roundtable (FRTR) will act as the coordinating body for the group. Under this organization, he said, conference calls will be set up and information will be posted to the Internet. (Puls said that information will be posted to the FRTR Web site and linked to the RTDF Web site.)

Puls noted that he is serving as the Principal Investigator for EPA's portion of the long-term performance project, which involves evaluation of three sites: Elizabeth City, the Denver Federal Facility, and Somersworth Landfill. Puls said that sampling activities will be initiated at the Somersworth Landfill site in late 1999. At the Elizabeth City and the Denver Federal Facility, he noted, core samples have been collected and data should be available soon. Puls said that some microbial data have been collected at the Elizabeth City site and that results are available. Although he did not have a chance to thoroughly review these data before the conference call, Puls said, one finding did jump out at him during his cursory review: there is a continuing trend of increasing microbial biomass in areas upgradient of the interface. One participant asked whether the microbial populations at the interface have been characterized. Puls reminded participants that he had not reviewed the data thoroughly, but did note that biodiversity is greatest at the interface and that it declines in areas deeper within iron-filled walls. Sivavec said that he was not surprised by this finding. According to one microbiologist he talked to, investigators should expect to see the greatest microbial populations in areas where there is an abrupt change in redox potential. Sivavec said that he would like to determine if this had been documented at other sites with PRBs and strongly recommended that microbial data be collected at all new sites that plan to install PRB systems.

MISCELLANEOUS

Korte asked whether anyone has researched situations where construction-related smearing causes mounding behind a barrier. Sivavec said that he is not aware of anyone researching this issue to date. Korte said that this scenario may be an issue at the Kansas City site, where contamination is being detected at either end of a long barrier. Warner said that mounding has been an issue at the Denver Federal Facility and the Sunnyvale site, but he said that the scenarios at these sites differ from the one that Korte described.

ACTION ITEMS

• Morrison agreed to contact site representatives from Cape Canaveral to determine whether the PRB Action Team could visit this site during the week of February 20, 2000.

• Over the next month, conference call participants agreed to find speakers for the February 2000 meeting. Puls said that he would find people to speak on site characterization issues. Korte and Liang agreed to find people to speak about the Kansas City site and Oak Ridge's Y-12 site, respectively. Other conference call participants agreed to find people to speak about activities at the Denver Federal Center, Shaw Air Force Base, and Travis Air Force Base.

• Warner noted that the first official PRB training course was held in Boston, Massachusetts, in June 1999. He said that the audience was receptive and had many questions. He agreed to summarize their questions and distribute them to the Steering Committee.

• Liang suggested having representatives from EPA, DOD, and DOE meet to discuss protocol and the scope of work for the long-term evaluation project. She agreed to set up such a meeting and to contact the appropriate people.

• ERG will set up a conference call for August 23, from 3:00 to 4:30 p.m. EST.