11:00 a.m.­12:30 p.m.
January 29, 1998

On Thursday, January 28, 1998, 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 Carrol, EPA
Bob Gillham, University of Waterloo
Richard Landis, DuPont
Stan Morrison, In Situ Barriers
Gary Jacobs, Oak Ridge National Laboratory (ORNL)

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

The meeting had four goals:

• Obtain an update from Steering Committee members on current activities, issues, and sites relating to PRB technology.

• Summarize the proceedings of a recent meeting that was held at ORNL.

• Discuss the agenda for the next RTDF meeting.

• Discuss a potential candidate to fill the empty co-chair slot.

UPDATES FROM MEMBERS ON CURRENT ACTIVITIES, ISSUES, AND SITES

Summary of a Recent Meeting in Tucson, Arizona

Dr. Morrison recently attended a 2-day meeting in Tucson, Arizona that focused on PRB technology issues. About 100 people attended the meeting, and Dr. Morrison was happy to report that he saw many new faces in the audience. According to Dr. Morrison, the meeting dealt with practical rather than fine-detailed technical issues and mostly covered topics that the Steering Committee has already been exposed to (e.g., organic degradation by zero-valent iron). One discussion that Dr. Morrison did regard as "novel" focused on biobarriers--a technology that utilizes "bugs" to create an exopolysaccharide slime-type formation that acts as a "slime barrier" to water movement. This technology is still in the "idea stage" and has not yet been executed at any site. According to Dr. Morrison, many people in the audience were intrigued by this technology and asked a significant number of questions (e.g., would the slime block the gate area if the technology was used in a funnel-and-gate system?).

Updating Ground-Water Remediation Technologies Analysis Center (GWRTAC)'s Documents

A couple of years ago, Dr. Morrison produced a GWRTAC document that compiled a list of PRB projects and a bibliography of papers relating to PRB technology. Dr. Morrison doubts that anyone has referred to the document recently because it is badly outdated. Dr. Morrison recently received money to update the document. He encouraged the Steering Committee to contribute information so that the document will be as complete as possible. Dr. Morrison will allow the RTDF team to review the document before posting it on the GWRTAC Web site. Dr. Puls recommended posting the completed document on the RTDF PRB Web site as well. The Steering Committee agreed, however, that links can probably be made between the two Web sites rather than posting the document in two separate locations.

ORNL Sites

ORNL is leading an investigation to treat a site contaminated with uranium, nitrate, and trichloroethylene (TCE). Two PRB systems have recently been installed:

• Funnel-and-gate system. This PRB system will utilize canisters, which will be replaced as needed. The reactive medium has not yet been installed at this site.

• Open trench system. This PRB system will consist of a 100-foot-long trench that will be kept open using guar gum. Gravel will fill the first portion of the trench, reactive iron will be placed in the middle of the trench, and additional gravel will be installed at the end of the trench. This setup is designed to intercept ground-water flow and to direct the flow through the reactive iron. A stream is located 40 feet from the trench. Researchers are already seeing iron staining and the guar gum is creating some significant biofilms. Dr. Jacobs refers to this site as "biochemically complex."

Caldwell Trucking Site

Mr. Landis and Dr. Gillham provided an update of activities at the Caldwell Trucking site in New Jersey. The team working at this site has grouted the bedrock zone and a cobbled area above the bedrock zone. Some vertical "fracturing" has been successfully conducted at this site.

Allied Signal Site

Dr. Puls summarized what he observed during his recent site visit to the Allied Signal site in Kansas City: a site which is contaminated with chlorinated solvents. In early February, a trencher will be used to install three parallel walls. Each wall will be about 150 feet long, 24 feet deep, 2 feet wide, and located about 5 to10 feet apart from each other. Iron, which will be used as the reactive medium, will extend from the bottom of the trench to 3 feet below ground surface in the first wall (the wall that the contaminants will first encounter). The other two walls will only have 6 feet of iron placed at the bottom of the trench. Dr. Puls told the committee that they can contact John Vogan or Paul Dieckman if they want additional information about this site.

Site in Monticello, Utah

Dr. Morrison told the Steering Committee that funding for a full-scale project was approved last week for a site in Monticello, Utah. MSE-Technology Applications, Sandia National Laboratory, and the University of New Mexico are heading up the project. The site, which is a mining site, should prove to be interesting because it is contaminated with metals (i.e., arsenic, selenium, manganese, and vanadium) and radionuclides (i.e., uranium), and has a high oxygen content. (Radium is also present at the site, but probably not in the area in which the wall will be installed. Nitrates and sulfates are present, but not at levels that need to be treated.) The team working on this project plans to perform laboratory and field work in the winter and spring and hopes to have the wall in place by October 1998. The team has not decided what reactive material to use, but is leaning towards zero-valent iron because it has already been proven to be very effective. Dr. Morrison encouraged the Steering Committee to offer input to this project.

Other Sites

According to Dr. Gillham, installation of continuous walls was recently initiated in:

• Oregon. This site is contaminated with chlorinated solvents.

• Upstate New York. Originally, a funnel-and-gate project was planned for this site, but when the project went full-scale, a continuous wall was installed.

• One of the Carolinas. There is some confusion among Steering Committee members regarding whether this site is located in North or South Carolina.

SUMMARY OF THE ORNL MEETING HELD ON JANUARY 22 AND 23, 1998

Dr. Jacobs is compiling a summary of the discussions at the ORNL meeting. This summary will be made available to the entire Steering Committee. The following people met at ORNL on January 22 and 23, 1998:

Bob Puls
Gary Jacobs
Thomas Early, ORNL
Nic Korte, ORNL
Ed Marchand, U.S. Air Force
Charles Reeter, Naval Facilities Engineering Service Center
Stephen White, U.S. Army Corps of Engineers
Liyuan Luang, University of Wales (formerly with ORNL)

The above-listed people met to discuss funding proposals that have been submitted to support long-term performance assessments of PRB systems. Three proposals have been put forth, spearheaded by:

• EPA. Bob Puls led this proposal effort.

• Department of Defense (DOD). Charles Reeter led this proposal effort.

• Department of Energy (DOE). Liyuan Luang led this proposal effort while she was still employed at ORNL.

Funding sources have indicated that money may be available to fund PRB projects. Before releasing funds, however, they would like to see more collaboration between EPA, DOD, and DOE. The ORNL meeting was held so that members from EPA, DOD, and DOE could identify common objectives that all of the proposals should incorporate. Dr. Puls hopes that collaboration between different organizations will make federal funding sources more likely to support PRB projects. The meeting was regarded as a success. The participants decided that a baseline of objectives can be established and written into all three of the above-listed proposals. (Charles Reeter's proposal is going to require the most changes. The modified version will bring in other parts of DOD, particularly the Air Force. Ed Marchand has expressed interest in helping Mr. Reeter). All three of the proposals will address the following questions/issues:

• What water quality parameters should be evaluated?

• How should the core samples be collected to best satisfy different objectives?

• What analysis should be performed from the core analyses?

• Precipitate build-up on walls.

• The positive and negative impact that microbes have on walls.

• Are there ways to study a site's hydraulics so that teams can identify early warning indicators of degradation efficacy?

The group plans to discuss these questions/issues more extensively and to produce a document that will serve to educate others who are assessing the long-term performance of PRB systems. (Dr. Puls encouraged other members of the Steering Committee to get involved with this effort.) The document will compile information generated at a variety of sites and will then be given to the RTDF team for review.

Dr. Puls is hopeful that long-term PRB performance will soon be tested at sites being investigated by:

• EPA sites: Elizabeth City, North Carolina and a site in Denver

• DOE: a site in Kansas City and the ORNL sites

• DOD: Moffett Field and maybe an Air Force site

• University of Waterloo: Dr. Puls hopes that Dr. Gillham will address long-term performance issues at an upstate New York site and at the Lowry, Colorado site.

AGENDA FOR THE APRIL 15 AND 16, 1998, RTDF MEETING IN PORTLAND, OREGON

Logistics

The next RTDF meeting is scheduled to take place on April 15 and 16, 1998, in Portland, Oregon. Dr. Puls has been working with Scott Warner and Paul Tratnyek to establish a meeting site for the RTDF team. They are currently trying to determine if there is a large enough meeting space available on the Oregon Graduate Institute (OGI) campus. If not, the meeting will be held in a hotel near OGI. Dr. Puls hopes to be able to confirm the dates and the meeting location by next week.

Meeting Format

The Steering Committee proposed the following meeting format:

• Presentations on installation methods

• Presentations on non-chlorinated solvent sites and non-iron reactive media. Although some of the presentations may focus on chlorinated solvent sites and iron-containing PRB systems, the group wants the majority of the discussions to focus on different contaminant classes (e.g., acid mining waste, radionuclides, hydrocarbons) and alternative reactive media (e.g., biological media).

• Panel discussions to provide site updates

• Poster Session. According to Dr. Puls, Paul Tratnyek suggested having a poster session at the close of the first evening.

• Field component. The field component will involve a visit to OGI's field pilot facility.

Potential Speakers

The Steering Committee hopes to get the following people/organizations/companies to present information at the April 1998 RTDF meeting:

• A representative from Battelle Pacific Northwest Laboratory (PNL). PNL has expressed interest in presenting information at the meeting.

• A representative from OGI. OGI has expressed interest in presenting information at the meeting.

• A representative from ORNL. As noted by Dr. Jacobs, someone from ORNL should be available to speak about the two new barriers that ORNL has recently installed.

• A representative from New Mexico Tech. Rob Bowman has expressed interest in presenting information at the meeting.

• Ed Marchand. According to Dr. Puls, Major Marchand has agreed to give a presentation on activities at Cape Canaveral.

• A representative from Golder. Dr. Gillham agreed to contact someone from Golder to see if they would present information about their experience with vertical hydrofracturing.

• A representative from a site in Oregon. Dr. Gillham agreed to contact John Vogan to see if he could get someone to talk about a PRB system that is located in Oregon. (Dr. Gillham was not sure of the exact location.) Although the site has chlorinated solvents, Dr. Gillham thinks it would be interesting to hear about some of the difficulties that the team encountered using trenching techniques.

• A representative from DuPont. Mr. Landis offered to talk about DuPont's experience with jetting technologies (e.g., work conducted at Dover Air Force Base). He also mentioned that DuPont might be willing to talk about their efforts to identify cheaper materials to use in PRB systems.

• A representative from Fry Canyon. Dr. Morrison offered to find someone to talk about Fry Canyon.

• Dave Blowes. Dr. Gillham offered to call Dr. Blowes to see if he would consider talking about non-chlorinated solvent sites (e.g., a site in Vancouver).

• Brian Dwyer. Dr. Morrison agreed to contact Brian Dwyer to see if he would consider talking about alternative reactive media.

Dr. Puls asked the Steering Committee members to get in touch with potential speakers quickly so that he, Scott Warner, and Paul Tratnyek can start putting the agenda together.