SUMMARY OF THE REMEDIATION TECHNOLOGIES
DEVELOPMENT FORUM
PERMEABLE REACTIVE BARRIERS
ACTION TEAM
STEERING COMMITTEE CONFERENCE CALL
11:00 a.m. - 12:30 p.m.
December 10, 1997
On Wednesday, December 10, 1997, members of the Permeable Reactive Barriers (PRB) Action Team Steering Committee of the Remediation Technologies Development Forum (RTDF) held a conference call. The following members participated:
Bob Puls (Co-chair), U.S. Environmental Protection Agency (EPA)
Dawn Caroll, EPA
Tom Early, Oak Ridge National Laboratory
Bob
Gillham, University of Waterloo
Rich Steimle, EPA
Tim Sivavec,
General Electric Corporate Remediation (GE)
Scott Warner, Geomatrix
Consultants, Inc.
Steve White, U.S. Army Corps of Engineers
After introductions, Bob Puls announced that he had a tentative agenda, but that people should feel free to add other topics and voice their comments and questions. Puls started the meeting opening a discussion of any new information regarding field projects, field research, and related topics.
Puls said that not much has occurred at Elizabeth City, North Carolina, since the Action Team’s September visit. However, in early November, EPA and Coast Guard representatives made their annual visit to Raleigh to brief state representatives on the project status. The state representatives were very pleased with the progress of the project and with the way the results were communicated to them. They made some good suggestions about how to explore the low-level TCE and DCE contamination occurring in the central and bottom portions of the wall. The state representatives expressed some concern about these contaminants, but they were clearly working with EPA in a cooperative manner to evaluate the data. Hopefully, EPA and state will continue to work jointly and have success on this project.
Responding to a question by Rich Steimle, Puls explained that no mechanism currently exists to continue detailed performance monitoring at the Elizabeth City site after June 1998. The interagency agreements between EPA and the Coast Guard end next spring, but EPA has managed to find in-house money to continue to support performance monitoring through June. The cooperative agreement between EPA and the University of Waterloo ends in June 1998. After this date, the Coast Guard will continue the low- level routine monitoring required by the state.
Elizabeth City is not the only site where a comprehensive monitoring program is in place. Bob Gillham discussed two sites, one in Denver and one in New York where the University of Waterloo collected and analyzed core samples last spring. The results from the two cores from Denver and the one from New York appeared fairly encouraging. Precipitates were forming, but generally the rate of precipitation was fairly consistent with what was expected. Relating the amount of precipitate formation to the change in hydraulic conductivities remains a problem: since no apparent relationship exists, it is difficult to access percentages of precipitates and conductivity. Currently, one of Gillham’s students is measuring conductivity and soon will be evaluating the amount of precipitation that causes a significant loss in permeability.
According to Tim Sivavec, GE has conducted a lot of laboratory column work, as opposed to obtaining cores. GE is running some analyses of precipitates to try to determine life time performance issues. They relate hardness and alkalinity in ground water with loss of pore space and permeability issues and translate that into conductivity as well. Work is in progress, but in the future GE will need to relate loss of permeability to conductivity. Thus far, GE has not seen anything alarming in the field.
Scott Warner described the monitoring program at the Sunnyvale site as the conventional program for regulatory information. There are quarterly monitoring rounds, the latest of which was in late November. Currently, they are awaiting these results. In the past three years, one or two sample rounds from within and outside the iron zone have been analyzed for inorganics. Last year samples were collected to ascertain the efficacy of biological activity both outside and within the wall. In 1999, Geomatrix Consultants, Inc. must submit a 5-year report to the regulation agency that discusses wall performance, including flow velocity, direction, and efficacy of the treatment. At Sunnyvale, and probably also at other sites, the hydraulic behavior within the wall changes as water levels fluctuate. This may be due to the difference between essentially semi-confined ambient systems and reconstructed unconfined natural systems. In California, where well-defined rainy and dry seasons occur, Geomatrix has seen some of these changes occurring. Over the next year, Geomatrix will focus on hydrologic changes when performing its assessments.
As far as Puls is aware, EPA’s SITE program underway at Rocky Flats remains on track.
Steve White announced that he was present at Major Marchand’s demonstration project in Cape Canaveral. The contracting company at this site, Formo Solutions, out of Denver, initially encountered many functional difficulties, including:
According to the contractor, however, progress at the Cape Canaveral site has increased immensely and the project was successful in both its mandrel and laboratory beam injection technology components. The mandrel placement of the 4-inch thick wall was accomplished before White arrived. White verified the success of the laboratory beam injection technology, but noted that Major Marchand was unavailable for comment about how he thought the second phase of the project had gone.
White announced that Formo Solutions is going to perform another pilot project using injection technology at Maxwell Air force Base in Alabama some time next month. No further details were given.
White also said that DOE is going to use a trenching machine to put in a wall at LI Signal, Kansas City. The initial excavation will occur within the next few weeks but specific dates have not yet been announced.
The USGS is continuing to conduct research on the Denver wall, and Steve White expects to receive a draft paper from them.
Discussing the Association of the Environmental, Bob Gillham noted that the market for barrier walls was flat from October 1996 to October 1997 and that no iron was placed on a commercial site during that 1-year period. There has been a drastic increase in activity between October 1997 and March 1998; eight iron walls are scheduled. At least three of these are already in place and one is going in currently. This may only be a temporary increase in activity and interest or it could be a trend.
The U.S. Army Corps of Engineers also has a site in the Missouri area where they have proposed constructing samples from within and outside of the iron zone a wall. This has not gone into the design phase yet, but White believes it will.
Gillham believes that the site in Kansas is one of the eight that the Association of the Environmental has on its list of projects that are virtually confirmed over the next two or three months.
Gillham also discussed progress at the New Jersey site, Caldwell Trucking, where Golder is doing their pilot tests with hydraulic fracturing. Golder did some cracking and inject grabbing to seal up fractures in the rock. In the shallower part of the bedrock they injected the iron-guar mixture. Gillham believes that Golder is probably in the process of creating fractures in the unconsolidated material and injecting the guar iron. Because this is the first significant site where this technology has been applied, people are interested in seeing how the project goes and how the technology performs.
White and Gillham concurred that work at the Cape Cod site is essentially on hold because the contractors are working in New Jersey. Gillham attended a meeting in Cape Cod three weeks ago at which the group decided to continue with the Golder technology as an option but also to look at the pneumatic fracturing technology under development by the New Jersey Institute of Technology as another option. The group hopes that both technologies will be evaluated at that site. If pneumatic fracturing is used, work is unlikely to begin until June 1998. If vertical hydrofracting is used, work might begin in the winter. The Cape Cod project was delayed because Golder had equipment improvements that took longer than expected; they were further delayed by their involvement with the Caldwell project.
Gillham continued by explaining that pneumatic fracturing has not yet been demonstrated to be a viable technology. There has only been one successful ground-water demonstration during which iron placed into the ground reduced contaminant concentrations, but the amount put in per square foot of flow area was small. Despite the small number of demonstrations, pneumatic fracturing appears quite promising.
Compared to hydraulic fracturing, pneumatic fracturing is more like soil mixing than like fracturing. Basically pneumatic fracturing involves applying a high pressure air stream (nitrogen was used in Kansas) into the ground that stirs up and mixes the iron over a small radius. Next, the equipment is withdraw a few inches and the procedure is repeated. The machinery used in this process is much more like jetting equipment than fracturing equipment.
Tom Early indicated that DOE recently confirmed its interest in attempting to coordinate long-term performance work.
Puls said he had communicated with most of the individuals who were helping to coordinate long-term performance work. Puls said that these individuals should soon meet to discuss strategies for obtaining EPA, DOE, and DOD funding that could be used for research into the long-term performance of reactive barriers, particularly the iron-based systems. The original proposal put forward by this group over six months ago still seems a fairly valid approach that can serve as the baseline for the new strategy.
Puls proposed that those interested in creating the strategy or doing the work itself, should attend a meeting hosted by DOE at Oak Ridge during the second week of January. Those most interested were:
Other individuals not listed are welcome to attend the meeting.
The group agreed to meet on Wednesday, January 14, 1998.
Bob Gillham recently heard of a multi-agency request (possibly by SERDP) for proposals involving inorganics and biological effects on long-term performance. Gillham guessed that it was approximately $600,000 per year over 2 to 3 years. Pre-proposals are due by January 10.
Other agencies, such as Brooks AFB, have issued similar announcements, so there are a number of calls for proposals out now. The ESPCP call will be out in early February and will not be due until early May.
The group discussed what the RTDF role should be amid all of these requests for proposals. The group members generally agreed that as more money becomes available for PRB research, it will be less important for the group to spend time accumulating funds. Instead, some sort of coordinating role might be more appropriate.
Numerous questions and complications arose when the group discussed how it could take on a coordination role. A problem with conflict of interest may exist if the steering committee members actually submit proposals for one agency or another.
Puls mentioned that the RTDF has been somewhat effective in calling attention to the need for long-term PRB research; he said that more organizations are inclined to support this research than they were a couple of years ago. The group agreed that the RTDF has been effective by these standards and speculated that there should be some way for the RTDF to remain involved through peer-review, advising, or similar activities. It was noted that the Action Team could be fairly effective in acting as an advisory committee because it is the only barrier wall organization in the country and has all of the experts. In such a capacity, the Action Team could help promote and answer questions about PRB technology. Overall, the group approved of taking on more of an advisory role, though some members are still primarily committed to doing research in this area.
White mentioned that the RTDF’s initial goals were to ensure that a number of diverse viewpoints and programs from the DOE, DOD, EPA, and private industry were combined to create a broader focus in terms of long-term monitoring. At the very least, the RTDF should make sure different groups understand that this broader picture of PRB walls exists.
Puls summarized the main reasons for forming the RTDF:
Gillham mentioned that no one (and certainly not the RTDF) is currently coordinating the two or three significant requests for barrier wall proposals that have recently come out. Therefore, he can only expect overlap and duplication in requests for proposals. He suggested that perhaps the RTDF should become more proactive and approach the agencies making requests. Puls responded that he would be worried about conflicts of interest. The group overall decided that they need to present themselves without these conflicts of interests and that the RTDF probably should not become involved in the proposals process. Instead, the RTDF may be able to direct ideas and research after funding has already been secured.
The group discussed the need for coordinating agency requests. Coordinating efforts might be feasible after a number of projects have been completed or are sufficiently far along because the RTDF could provide data and experience analysis. The RTDF experience could help researchers tailor their proposals so that the proposals are not limiting or rigid. (Warner mentioned the bad experience with the Dover test site proposal where the researchers were unable to change their goals and incorporate new information into their study because of the rigidity of the proposal terms.) Concern arose about the potentially overwhelming work and time commitment all of these coordinating services would entail. It was agreed that the RTDF should continue to offer advice to researchers by helping them identify particularly relevant study sites, but no specific action plans were created.
Puls said that the steering committee had not yet identified anyone to replace Dale Schultz. Puls received offers from two groups: MSE-Technology Applications, Inc., and Regenesis Bioremediation Products. These offers were not necessarily for the co-chair position, but both corporations would like to be more active in the RTDF group.
MSE-Technology Applications, Inc., is a group from Butte, Montana, that frequently compiles and coordinates DOE projects and has some minimal involvement with EPA and DOD. MSE offered in-kind resources and possibly funding for a particular action team project.
It was decided that at the January meeting the steering committee would look at the near- and long-term goals of the PRB Action Team. Clearer advisory and research goals may help solidify where the group is going and its future role. The PRB Action Team will then decide which members should constitute the group. Anyone interested in co-chairing should get in touch with Puls.
Puls has received numerous suggestions and requests regarding the meeting location. After much discussion, the group chose to meet in Portland, Oregon, at the Oregon Graduate Institute (OGI), in early April. OGI was chosen because of its proximity to the airport (35 minutes from Portland, on a good day), its technological resources (a test reactor located right on campus), and its diversified research (investigating different media and zealites).
The spring meeting will be structured much like the last one. There was positive feedback about the site updates from previous meetings.
For the scope of the spring meeting, the steering committee wanted to de-emphasize chlorinated solvents and iron and to emphasize other types of reactive media and contaminants. There was general agreement not only about introducing some topic diversity into the program, but also about arranging for some new speakers and presenters. The group will identify potential speakers, who will be asked to submit abstracts. All abstracts should be sent to Puls.
Warner is pursuing meeting details with OGI.