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

11:00 a.m.–12:30 p.m.
October 22, 2001

On Monday, October 22, 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)
Arun Gavaskar, Batelle
Charles Reeter, U.S. Naval Facilities Engineering Service Center
Edward Seger, DuPont
Tim Sivavec, General Electric Corporate Remediation
Richard Steimle, EPA Technology Innovation Office (TIO)
Matthew Turner, New Jersey Department of Environmental Protection
Olivia West, Oak Ridge National Laboratory

Also participating in the call were Carolyn Perroni from Environmental Management Support, Inc. (EMS), and Christine Hartnett from Eastern Research Group, Inc. (ERG).

NEXT STEPS FOR THE PRB ACTION TEAM

Implementing a New Monitoring Project

Conference call participants agreed that the PRB Action Team should initiate a monitoring project to generate additional data on PRBs. If an extensive database is assembled, they reasoned, it may help convince potential users to choose a PRB as a remedial tool. The following was proposed:

·         Collect extensive data at two or three PRB sites. Tim Sivavec said that it would be useful to design and implement a monitoring project at a newly built PRB installation. It was agreed, however, that beneficial information can also be gleaned by assessing older PRBs. Bob Puls said that both approaches have merit and asked call participants to research a range of possibilities.

·         Obtain funding through multiple sources. Puls said that new funding sources will need to be sought for the monitoring project, but that it might also be possible to leverage existing monies.

·         Include innovative monitoring techniques. Sivavec expressed interest in experimenting with passive sampling techniques that would not disturb hydraulic gradients.

·         Collect performance data. Participants agreed that the monitoring study should collect information about PRB performance, including information on the longevity of reactive materials.

·         Develop a “smart monitoring” program. Call participants agreed that one of the project’s goals should be to identify an “ideal” monitoring program. Effort should be made to get the most bang for the buck, and to identify cost-effective sampling methods. It would be useful, Sivavec said, to identify indicator parameters that can be relied upon to predict performance at different sites.

The following call participants expressed interest in developing an RTDF monitoring program: Sivavec, Oliva West, Arun Gavaskar, Charles Reeter, Ed Seger, and Matthew Turner. A conference call will be held within the next 6 weeks to discuss the project in more detail. (All interested parties will submit e-mails to Puls letting him know which dates would not work for a call.)

Creating a Publication That Highlights the Success of PRBs

Call participants agreed that a document should be written to summarize the state of PRB technology. It should be targeted to potential users and written in concise and accessible language. It should incorporate information about PRB development around the world, not just in the United States. The final report will be available in hard copy and posted on the RTDF Web site.

NEXT PRB ACTION TEAM MEETING

Call participants tentatively agreed to hold the next PRB Action Team meeting in August 2002, in Baltimore, Maryland. Reeter will contact Lynn Roberts (of Johns Hopkins) to determine whether she is willing to give a presentation. In addition, efforts will be made to solicit international speakers. (Puls and Sivavec will do the recruiting.) Call participants agreed that it would be interesting to discuss the difference in PRB design between Europe and the United States. During the meeting, it would also be useful to obtain updates on the major PRB projects that are currently underway.

PRB PROFILES

Carolyn Perroni said nearly 60 site profiles have been posted to the RTDF Web site, and that the site is soliciting many visitors. She had hoped to post more profiles, but has not received many since June 2001.

UPDATE ON THE LONG-TERM PERFORMANCE MONITORING STUDY

Puls said that EPA, the Department of Defense (DOD), and the Department of Energy (DOE) collaborated on a 3-year long-term performance study. This project is nearing completion. In fact, in early 2002, EPA plans to print and post (on the Internet) a report about the sites it studied. In late October 2001, DOD and DOE will release reports on the sites they were involved with. Gavaskar also noted that a short report will be written to summarize the results obtained by all three agencies; this will be posted on the Internet.

Puls and West indicated that cementation has been detected at two of the sites participating in the long-term performance study. At the Denver Federal Center, Puls said, cementation was observed in Gate #2, an area plagued with difficulty ever since the PRB was first installed. (There is high microbial activity around this gate, as well as high sulfate concentrations and low ground-water flow conditions. Also, smearing may have occurred during the PRB construction phase when sheet piles were removed.) West said that the cementation observed at the Oak Ridge Y-12 plant is located at the interface between gravel and the PRB’s reactive material (i.e., iron). Sivavec noted that both of these sites use a “100% iron” design, and asked whether this might make the sites susceptible to cementation. Puls did not think so, noting that other sites have used this design without experiencing similar problems.