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

11:30 a.m.­1:00 p.m.
June 1, 1998

On Monday, June 1, 1998, 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)
John Vidumsky (Co-chair), DuPont
Dawn Carrol, EPA/Technology Innovation Office (TIO)
Bob Gillham, University of Waterloo
Donald Marcus, MacMarcus Resources
Timothy Sivavec, General Electric Corporate Remediation
Richard Steimle, EPA/TIO
Robert Stamnes, EPA
Scott Warner, Geomatrix Consultants, Inc.
Stephen White, U.S. Army Corps of Engineers

Also present was Christine Hartnett of Eastern Research Group, Inc. (ERG).

OPEN DISCUSSION OF NEW ACTIVITIES, INFORMATION, AND SITE PROGRESS

Conference call participants summarized ongoing activities at:

• Otis Air Force Base (AFB) in Massachusetts. Bob Gillham said that Golder Sierra is installing a vertical fracture wall at Otis AFB. The wall is being installed at 80 to 120 feet deep, deeper than any previous implementation. Gillham said the wall consists of two parallel fracs. Given that perchloroethylene concentrations are 200 to 250 parts per billion (ppb) and trichloroethene concentrations are 10 to 15 ppb, Gillham said that a single frac four inches thick should be sufficient to reach maximum contaminant levels.
• Maxwell AFB in Alabama. Stephen White said Foremost Solutions is scheduled to install a hydrofrac wall in June 1998 at Maxwell AFB. White has not seen detailed specifications for the project but has heard that guar gum will be used at the site.
• Somersworth, in New Hampshire. Timothy Sivavec said that core samples were collected from the Somersworth Landfill site in April 1998. These samples are being analyzed, and Sivavec was optimistic that results will be available by mid-June. He noted that Bob Puls is assisting with the carbonate analysis and that CRD is performing the surface analysis. Sivavec said that no evidence of biofouling has been detected. Based on results to date, Sivavec said he is optimistic that a full-scale funnel-and-gate system will be installed at Somersworth. He thought the system would be shorter than was proposed, however.

Scott Warner told conference call participants that he attended the Batelle conference in Monterey, California. Warner said the meeting was well-attended and quite successful; many talks focused on treatment walls. Warner said the abstract and the summary of the meeting will likely be quite informative. Warner was impressed with the geochemical monitoring that Batelle had performed and was encouraged to learn that many of the trench-type treatment sites (e.g., Sunnyvale and Denver) are generating similar organic and inorganic results.

PRB DOCUMENT REVIEW

The RTDF team has completed a first draft of a document focusing on PRB technologies. Before the June 1, 1998, conference call, the document was distributed to the Steering Committee for review. Puls said that he released 14 copies for review. These copies went to the document's authors, Steering Committee members, and members of EPA forums. Puls said he will accept comments until mid-June. Ideally, he would like the report to be finalized before the end of the fiscal year (i.e., September 1998).

Puls asked the conference call participants whether they had specific comments they wanted to make. Participants offered several stylistic comments, including:

• Broadening terminology. Donald Marcus noted that some of the document's terminology is inconsistent and should be evaluated further. He recommended using the term "permeable reactive zone" rather than "permeable reactive barrier" because the former is more generic and encompasses a wider range of treatment systems. Marcus said that the word "barrier" implies a physical and continuous structure. Many of the newer technologies, he argued, are not continuous physical barriers. As examples, he cited reactant sand-fracking, a treatment system that has been piloted in Newbury Park, California, and dithionite barriers, a chemically in-place system that is being tested by Fruchter.

  Richard Steimle agreed that "permeable reactive zone" is a more appropriate term. He said that the phrase "permeable reactive barrier" has always troubled him because objects that are permeable are not really barriers.

  Gillham and Puls agreed that Marcus made a valid point. They were reluctant, however, to supplant the current term because it has become well-known in the science community. Puls agreed to look more closely at the document to identify specific places where the terminology should be broadened. Marcus strongly encouraged Puls to reevaluate the abstract and the introduction and to consider using the word "zone" rather than "barrier" in these sections.

• Using consistent language. Marcus noted that the authors who contributed to the document did not use consistent language. For example, some authors used the word "trichloroethene" while others used "trichloroethylene." Marcus said he preferred the former because it is more popular in academic publications. Marcus said he had found other inconsistencies but thought it better to submit them to Puls directly rather than to discuss them during the conference call.
• Adding a definition and an acronym list. Warner and Marcus recommended adding a definition or an acronym list. Puls agreed.
• Calling out acronyms and citations. Marcus recommended highlighting acronyms and references in bold print. He said that such an approach would make the document more consistent with academic papers.
• Streamlining the text. Marcus recommended placing some of the text's detailed information in an appendix. With this approach, he stressed, readers can choose the amount of detail they want.
• Unifying the voice. Because multiple authors contributed to the document, Marcus said that the document's voice is inconsistent.

Robert Stamnes said that the document currently includes about 10 case histories. He said he thinks additional sites could be included, as well. Puls said he was trying to identify the best approach for discussing sites. He said it would be impossible for the document to ever be truly current because PRB treatment projects are added so quickly. Puls said that some Steering Committee members had suggested omitting sites from the document and simply referring the reader to the RTDF Web site for detailed site information. (Puls said site-specific information is not yet available on the Web site but that it will be soon.)

Stamnes and Gillham agreed that the case studies should remain in the text. As Gillham noted, case studies help readers understand how to put a technology into practice. White agreed, stating that case studies help express the lessons that have been learned and the mistakes that investigators have made. Gillham recommended leaving a few case studies in the text but referencing the reader to the Web site for additional information. He said the case studies could be presented in more detail than would be provided on the Web site. Puls thought Gillham's suggestion was good.

Puls said the Steering Committee has not made a final decision about who will receive the finalized form of the document. He said EPA typically sends documents to universities, state offices, EPA labs, EPA headquarters, and EPA regional offices. Puls stressed that the Steering Committee members are free to place anyone they want on the list.

Warner commented that a number of PRB documents have been released recently or will soon be released, including those by:

• The Interstate Technology Regulatory Cooperation (ITRC) Working Group. Puls said ITRC released in late 1997 or early 1998, a document focusing on PRB technologies for remediating chlorinated solvents.
• Batelle. Warner noted that Batelle is publishing a book on the design of reactive barriers. Puls said that Batelle's book will not offer new information but will simply place a previous document in book format.
• Elsevier. One participant noted that Lakshmi Reddi, from Kansas State University, is helping to compile a volume on PRB technologies.

Given that so much information about PRB technologies is being released, Warner stressed that the RTDF team should avoid producing a document that repeats the material in other documents. Marcus agreed that it is pointless to "reinvent the wheel" but said he thinks it is important to draft documents in which readers can find all the information they need and that which prevent them from referencing numerous documents.

SUMMARY OF ITRC MEETING IN WASHINGTON, D.C.

Puls and John Vidumsky summarized the proceedings of the ITRC meeting that took place in Washington, D.C., in mid-May. Puls explained that the ITRC gathers annually in Washington, D.C., to discuss workshop ideas and identify the activities they want to pursue in the immediate and long-term future.

On the first day of the meeting, Puls said, several talks were presented by high-level EPA, Department of Defense (DOD), Department of Energy (DOE), Navy, and Air Force personnel. Talks focused on ways to implement innovative technologies and to address concerns that have been raised.

Puls said that, to brainstorm ideas, the ITRC participants split into four subgroups, one of which focused on PRB technologies. According to Puls, the PRB subgroup focused its discussions on inorganics and radionuclides and proposed writing documents to address how PRB technologies could be used to remediate these contaminant classes. Vidumsky noted that extensive regulatory issues must be considered when approaching radionuclide waste sites. He suspected, therefore, that the ITRC Working Group will address inorganics and radionuclides in two different documents: one that focuses on metal-contaminated sites and only briefly mentions radionuclide-contaminated sites and a second that focuses solely on radionuclide waste. (Puls said that the ITRC members noted that there are not currently many PRB installations at radionuclide sites. This will likely change, however, because DOE plans to install a number of walls to treat uranium and strontium contamination.)

In terms of inorganic-contaminated sites, Vidumsky said that the PRB subgroup thinks chromium-contaminated and arsenic-contaminated sites will prove the best candidates for PRB technologies. He said some discussion also revolved around using PRB technology to remediate nitrates. (Vidumsky said that nitrate contamination is of particular concern to DOE because DOE has used huge volumes of nitric acid to produce uranium.)

One conference call participant asked whether the ITRC Workgroup had discussed the difficulties they have encountered when trying to get concurrence on a document. Puls said there was little discussion on this but that he believed ITRC was still having some trouble.

PRB TRAINING

Warner said the PRB Steering Committee has been talking about creating a PRB technology training program. Such a program, he noted, would help ensure that regulators, implementors, and designers are consistent in their approach for addressing PRB technologies. To try to gather ideas for the PRB course, Warner has contacted many of the people who were instrumental in designing the natural attenuation course, like Matt Turner, Dan Sagorka, and Steve Hill. The natural attenuation course, which is sponsored in part by the RTDF's Bioremediation Consortium, ITRC, and Southern States Energy Board, has been immensely popular and has been presented in about eight different U.S. locations over the past 7 months. Each session, Warner noted, drew excellent attendance (i.e., 200 to 300 people).

Warner has drafted a model proposal for a PRB training program. Warner's proposed 1-day course is designed to cover numerous topics, mainly design, lessons learned, regulatory issues and concerns, and implementation. Warner also recommended including exercises so participants could delve into problems and work through them with instructors. The course would introduce definitions, key terms, and key concepts. Warner said the course would be targeted mostly to EPA and state regulators. (At the natural attenuation training sessions, about 60 to 70 percent of the attendees are regulators.) He is hopeful, however, that many consultants and industry representatives will also attend so that communication lines are established among implementors, reviewers, and regulators.

Warner discussed funding issues. Again, he researched the natural attenuation course for guidance. He said that the natural attenuation course was originally projected to require about $500,000. Organizers for this course were able to get the course "up and running" with $50,000 seed money. Warner said that fees are not charged to regulators who attend the natural attenuation course and that only nominal fees are charged to industry and consulting representatives. Instructors involved with the program are given money only for their travel and expenses and are not compensated for the time they take to prepare materials. (Warner recommended offering honorariums to instructors who participate in the PRB training.)

Warner said that ITRC has expressed interest in helping to sponsor the PRB training program during fiscal year 1999. Warner said he has identified other organizations that might also be willing to contribute. Steimle said that EPA might be able to help fund state regulators' travel expenses.

Conference call participants were generally enthused about the idea of sponsoring a training program. One participant suggested distributing Paul Tratnyek's CD-ROM during the training session. Puls warned that a representative from the Southern States Energy Board claimed that the Board has already created a PRB training program. According to Puls, the representative did not indicate whether the Board wanted the RTDF team to participate or if there were other sponsors. Warner was surprised to hear of this development and was sure that others, like Matt Turner, Dan Sagorka, and Steve Hill, would also be surprised.

To date, Warner has released his proposed training model to Puls and a few other Steering Committee members. He agreed to distribute the proposal to the remainder of the Steering Committee so that the group can decide whether it wants to proceed with the project. Warner agreed to investigate the Southern States Energy Board's training plans. Assuming that the RTDF decides to conduct the training, sessions would start during fiscal year 1999. Ideally, Warner said it would be beneficial to dovetail with the last natural attenuation meeting (scheduled in May or April 1999 in Chicago). Warner said he thinks the PRB training course will generate significant interest, particularly because the course will coincide with the release of a number of related documents.

PLANS FOR NEXT MEETING

Logistics

Puls noted that the RTDF team has settled into a pattern of meeting once every 6 to 7 months. The conference call participants agreed that this is a good schedule and tentatively scheduled the next meeting for November 1998.

Conference call participants listed numerous places where the meeting could be held, including (1) Cape Canaveral, (2) Savannah River, Oak Ridge National Laboratories (ORNL), (3) Boston, Massachusetts, and (4) Washington, D.C. The participants decided that ORNL was the best option. A couple of participants were enthused about holding the meeting at ORNL, claiming that ORNL is one of the forerunners experimenting with PRB systems (with unusual media) to remediate radionuclide waste. Puls said he would contact Gary Jacobs to explore the ORNL option. One participant warned that ORNL has strict security protocols and will not allow noncitizens onto the property unless the noncitizens' names are submitted several months in advance.

Meeting Format

Puls noted that the RTDF's contractor distributed a questionnaire at the RTDF PRB Action Team Meeting held in Portland, Oregon, in April 1998. The questionnaire asked for feedback on how RTDF PRB meetings are conducted. Puls said that he would send the questionnaire results to the Steering Committee members. In summary, he said, the responses were largely favorable and constructive. The main comment was that the meetings should contain more discussion time, either by (1) limiting speaker time, (2) extending the question-and-answer session, and/or (3) including a roundtable or panel discussion.

Many conference call participants agreed that it is a good idea to include a roundtable or a panel discussion. One participant recommended holding miniroundtable discussions throughout the meeting to ensure that people stay focused. Some participants thought more time for questions and answer should be incorporated after each speaker. One conference call participant thought this might slow the meeting too much. Puls said that one questionnaire respondent recommended giving each speaker a half-hour to speak but making him or her cut the presentation after 20 minutes.

Puls said the questionnaire responses indicate that team members want discussions to focus on (1) installation methods, (2) regulatory issues, and (3) long-term monitoring. The conference call participants agreed that no more than one-quarter to one-half a day should be dedicated to regulatory issues. One participant suggested addressing long-term monitoring in a large roundtable discussion. Time expired on the conference call before participants could finalize plans.