Remediation Technologies Development Forum (RTDF)
Permeable Barriers Action Team Meeting Summary

San Francisco, CA
August 15-16, 1996

August 15, 1996

Welcome and Review of Agenda

Dale Schultz (DuPont), co-chair of the RTDF Permeable Barriers Action Team, welcomed participants to the meeting. Earlier in the day, the Action Team members visited two sites, Interstil, Sunnyvale, CA, and Moffett Federal Airfield, CA, where permeable barrier systems have been installed. Dale thanked Scott Warner (Geomatrix) and Chuck Reeter (Navy) for coordinating the visits to the respective sites. Both Scott and Chuck reported that "their" respective field demonstrations are successful to date. Dale indicated that the remainder of today's meeting will be primarily dedicated to discussions of permeable barrier field demonstrations. Degradation chemistry and engineering aspects of permeable barriers will be discussed during tomorrow's session.

Overview of California Regional Water Quality Control Board

Brad Job (California Regional Water Quality Control Board) provided an overview of the California Regional Water Quality Control Board (CRWQCB) and its role as it pertains to the implementation of innovative technologies. He also discussed the justification for use of a permeable barrier at Interstil. Brad indicated that a number of factors were conducive to the implementation of an innovative technology at Interstil, including:

However, Brad noted that there were a number of difficulties to overcome before the permeable barrier system was agreed upon by all concerned parties. A number of neighboring property owners expressed concern about the viability of a permeable barrier system and all PRPs were not initially agreeable to a permeable barrier system. The concern of neighboring property owners was significant because of possible offsite migration of contaminants if the permeable barrier failed. Brad identified the following advantages to a permeable barrier system:

Interstil appeared to be well suited for a permeable barrier and the system appears to be functioning quite well. It has been operational since January 1995, and monitoring result show that water quality objective are being met. Brad provided an overview of a number of Regional Water Quality Control Board (RWQCB) statutes and regulatory policies that may impact the implementation of a permeable barrier system, including:

Brad indicated that these statues and policies provide a mechanism to approve an innovative technology. However, he suggested that some guidelines may be prohibitive and noted that the CRWQCB aims to develop appropriate cleanup goals by considering watershed management, receptor identification, risk analysis, economic analysis, and data management. Growth issues will be investigated- risk analysis and risk economics were identified as two such issues. Brad identified the following regulatory initiatives to encourage the development of innovative technologies:

Brad emphasized the importance of the Brownfields initiative and indicated that all of the above mentioned initiatives are, in part, intended to encourage PRPs to work together to solve their mutual problems. Brad added that efforts have been initiated to develop interstate/intrastate cooperation. Standards for multimedia risk evaluation, risk communication, and data sharing are under consideration and Brad noted that the interplay of thesethree factors is important to understand the hazards of a site.

In response to a participant's question, Brad indicated that zero-valent iron technology used successfully in numerous permeable barrier systems has not been certified. Chuck Reeter and Scott Warner agreed to determine if certification is advantageous to the permeable barrier technology. He noted that the demonstration design for Interstil was approved in approximately 3 months once the formal request was made. However, the CRWQCB and other regulatory agencies were involved in the developmental process, which expedited the approval process.

Overview of the ITRC

Paul Hadley (Cal-EPA) provided an overview of the ITRC and noted that Brad Job accurately related a number of the ITRC objectives. The ITRC is a state-lead organization promoting the development, demonstration, verification, acceptance, and interstate deployment of innovative environmental technologies. Stakeholder, tribal, and industry representatives participate in the ITRC, which was formed in February 1995. Paul clarified that the industrial participants are not ITRC members per se, but they are involved in most facets of the ITRC. There is participation from the 27 states listed below, and Paul indicated that additional states are encouraged to join:

Arizona Louisiana Ohio
California* Maryland Oregon
Colorado Massachusetts* Pennsylvania*
Delaware Minnesota South Dakota
Florida Nebraska Tennessee
Illinois* Nevada Texas
Idaho New Jersey* Utah
Kansas New Mexico Washington
Kentucky New York* Wisconsin

Paul indicated that six states (indicated by an asterisk above) have entered into a Memorandum of Understanding (MOU) to accept field data generated within one of the other states to promote technology transfer. The ITRC works actively with a number of federal agencies, including the Department of Energy (DOE), Department of Defense (DOD), and EPA. Several task groups have been formed since the inception of the ITRC, with the following focus areas- low temperature thermal desorption, in-situ bioremediation, plasma technology, site characterization and analysis penetrometer system (SCAPS). Paul noted that a "circuit rider," Rich Tomlinson, has also been identified for the ITRC. The ITRC In-situ Bioremediation Work Group has been working with the RTDF Bioremediation Consortium, and Paul, who is a member of the ITRC In-situ Bioremediation Work Group, believes that the relationship is mutually beneficial. A permeable barriers focus group will be formed in the near future, and Paul suggested that the RTDF Permeable Barriers Action Team work cooperatively with the ITRC Permeable Barrier Work Group. An objective of the permeable barrier focus group will be to obtain state regulatory and stakeholder acceptance of the technology. The Permeable Barriers Action Team will develop design protocols and it was suggested that the ITRC could provide a forum for review of the materials. It was suggested that the ITRC could define performance and criteria necessary to meet performance for SERDP Project #107 at Dover AFB, DE; Moffett Federal Airfield, CA; and Somersworth, NH. Steve McCutcheon (EPA/NERL), co-chair of the Action Team, indicated that he has spoken with Matt Turner (New Jersey Department of Environmental Protection), the anticipated chair of the ITRC Permeable Barriers Work Group, to identify a means for the two groups to work together and to discuss these suggestions and others. Steve also noted that Steve Shoemaker (DuPont) will interact with the ITRC on behalf of the Action Team. Jeff Marquesee (DOD) agreed that the RTDF and ITRC should interact regularly. In addition to the permeable barrier focus group, ITRC additional groups will be formed to: facilitate the integration of state efforts across working groups, review innovative state programs, and to increase electronic transfer of information.

Paul identified the following outputs of the existing focus groups:

Paul added that seven states, New Jersey, New Mexico, California, Nebraska, Utah, Louisiana, and Idaho, co-signed the SCAPS report.

Paul identified the following benefits of the ITRC to the participating organizations:

A number of advantages were also identified for industry participants:

The ITRC endeavors to: become involved with real projects as they are designed, provide necessary regulatory input as early as possible, and seek as much regulatory consensus as possible to promote the "acceptance" of a technology. Paul noted that reaching an agreement on the definition of acceptance has been difficult. The ITRC seeks to participate in demonstrations with state regulatory and stakeholder involvement, develop protocols (define technology requirements and identify regulatory implications and requirements), and gather cost and performance data. "Performance" is another term that is difficult to define.

Update on Studies at Somersworth Sanitary Landfill

John Vogan (ETI) provided a brief update on column studies underway at the Somersworth Sanitary Landfill (Somersworth), Somersworth, NH. Elevated levels of volatile organic compounds (VOCs) are found in the groundwater. John indicated that one objective of the column studies is to examine the VOC degradation rate in order to arrive at an optimal field design. The column studies were performed using 100% iron as well as 50% iron mixtures. Different types of iron were explored, and John indicated that results obtained to date were, in general, consistent with previous experiences. However, John did note that Connelly-GPM iron exhibited similar results to that of Peerless iron, which was unexpected based upon the surface area of the materials.

A funnel and gate system (F&G) will be emplaced at Somersworth, and construction of the pilot-scale system is expected to begin fall 1996. A groundwater model is under development and near completion, which will be used to determine the necessary residence time. John indicated that various emplacement methods are under consideration.

Update on Studies at United States Coast Guard Support Center

Bob Puls (EPA/NRMRL) provided an update of ongoing studies at the United States Coast Guard Support Center (USCG) in Elizabeth City, NC. Bob acknowledged the participation of the University of Waterloo, the U.S. Coast Guard, and the State of North Carolina in the efforts at USCG. The USCG is located on the southern bank of the Pasquotank River. The demonstration site, outside of Hanger 79 at USCG, is approximately 60 feet from the river and was used for more than 30 years as a chrome plating shop. Bob indicated that acidic chromium wastes and associated solvents were discharged through a hole in the concrete floor and Bob indicated that the chromate plume has reached a receptor. A pilot test was begun in 1994 and has been monitored over the past 2 years. The primary objective of the study was to remove chromate contamination from the groundwater. Bob noted that two sources of iron were used in the pilot study- Masterbuilders and an iron developed at EPA's Kerr Laboratory. Hollow stem augers were used to emplace the iron in approximately 10-inch (diameter) columns. Bob indicated that a number of groundwater parameters were monitored. Dissolved oxygen (DO) decreased to non-detect levels; Eh lowered, pH was stable until March 1995, at which point it increased. Bob indicated that trichloroethene (TCE) levels were seen to decline and then rise. However, Bob noted that the field test was not designed to remediate chlorinated solvents so the residence time may not be appropriate for TCE remediation. In response, to a participant's question, Bob indicated that there is slight seasonal variation in the groundwater flow direction, which Bob speculated may account for a slight rise in chromate levels during one sampling interval. Elevated ferrous levels are seen within 1 meter of the columns.

Based upon the success of the pilot study, a full-scale effort was emplaced in June 1996. Two major plumes have been targeted in the full-scale effort- a chromate plume and a smaller chlorinated solvents plume. The objective is to reach regulatory limits for Cr(VI), TCE, cis-DCE, and vinyl chloride (VC). The emplaced iron wall was 50 m x 8 m x 0.6 m, used approximately 500 tons of Peerless iron, and cost about $300-350K to install. A trencher was used to emplace the wall, and Bob noted that the excavated materials were tested to determine if they were hazardous. Hazardous materials were relocated for treatment; non-hazardous materials were moved to another region of the USCG base. In response to a participant's question, Bob indicated the wall thickness (2 ft) is thicker than necessary. A 6-inch wall is necessary to address the chromate, and a 1.5 ft wall was needed to address the DCE. Bob indicated that initial plans called for installation of 2 parallel walls, both 1.5 ft thick, but that the design plan was modified to a single 2 ft wall. Operation and maintenance (O&M) costs are expected to be minimal, and the majority of the installation costs is associated with the iron. In response to a participant's question, Bob noted that the installation cost does not include site characterization or performance monitoring.

Performance monitoring devices have been employed with increased emphasis on accurate and efficient monitoring throughout the durationof the project. Bob indicated that tracer tests, microbial assessments, geophysics (to monitor wall integrity) tests will be performed. Four upgradient wells and six downgradient wells will be emplaced in addition to wells emplaced within the wall. Bob indicated that half of these compliance monitoring wells have been emplaced and that preliminary results indicate successful remediation of the chromate. Bob noted that conclusive data have not been collected to determine the efficacy of the system to remediate chlorinated solvents.

Update on SERDP Project #107

Jeff Stinson (Air Force) provided an update on the Strategic Environmental Research and Development (SERDP) Project #107, to be performed at Dover AFB, DE. The SERDP-project will investigate the degradation of chlorinated solvents using several different reactive media in a funnel and gate system (F&G). The RTDF Permeable Barriers Chlorinated Solvents Design Team met yesterday, August 14, 1996, to discuss the design and implementation of the permeable barrier system. Jeff indicated that four reactive media will be investigated via column studies in the near future, and that the most promising two or three of these media will be selected for use in the field demonstration. In addition, a long-term column study is under consideration, possibly at Dover AFB, to investigate the most promising reactive medium. A strawman design for the demonstration will be developed by early fall 1996. A draft protocol on permeable barriers is expected to the completed by January 1, 1997, and field construction should begin in March 1997.

The Design Team tentatively agreed to a system with a 10 ft gate for each reactive media Jeff noted that innovative emplacement technologies are under consideration to emplace portions of the F&G system. DuPont is investigating jet-grouting and Rich Landis (DuPont) indicated that the studies, to be performed at Dover AFB, should be completed by late fall 1996. Jeff indicated that a short list of potential reactive media has been identified, including: zero-valent iron with an oxygen scavenger such as troilite (to minimize precipitation/plugging), zero-valent iron with a buffering agent, such as pyrite, and Cercona pellets. Jeff added that the Remedial Cost Engineering and Requirements System (RACER) version 3.2 has been released and that it contains a permeable barriers module.

Overview of the Navy's Cost Modeling Module

Brad Schwartzman (Naval Facilities Engineering Southern Command) provided an overview of a permeable barriers costing model, dubbed SUCCESS, developed by the Navy. He indicated that the model is available to all DOD personnel, but it is not currently commercially available. Version 2.0 should be available by spring 1997, and Brad indicated that this version will be much more flexible than the current version. Although DOD will continue to use RACER, SUCCESS is expected to be used to a greater extent. The flow chart on the following page depicts the decision tree that the user follows to generate the cost estimate for a hypothetical permeable barrier system. Brad noted that the current module restricts emplacement to less than 50 ft because current emplacement costs are quite high for deeper systems. Brad demonstrated SUCCESS, which provided participants with a real-time example of its use.

Overview of Oak Ridge National Laboratory, Studies

Liyuan Liang (ORNL) provided an overview of the recent studies on radionuclides conducted at ORNL and DOE's Portsmouth Gaseous Diffusion Plant (PGDP). Liyuan noted that it is often difficult to treat radionuclides in-situ because they are not degraded, they must be removed from the subsurface. She has also been investigating chemical and physical methods for removal of VOCs. An interim report of the studies conducted at the PGDP Groundwater Remediation Facility is available. The preliminary design for these studies was completed in winter 1995; laboratory studies were performed in spring 1996; analyses of laboratory studies were completed during summer 1996. Additional studies are expected to occur in fall/winter 1996. The objective of the studies was to evaluate permeable barrier technology. Liyuan indicated that above-ground canister systems were used to investigate Peerless iron, Masterbuilders iron, and palladized iron. Liyuan indicated that the degradation rate observed in the system using palladized iron was 10 times faster than that of the other media, but also mentioned that it costs substantially more than the other investigated media.

There was no pumping per se into the canisters- they relied on gravity flow. The dissolved oxygen in the groundwater was very low. Liyuan indicated that hydrogen gas, bacteria build-up on the filter column, and iron oxide precipitation in treatment system were seen in a number of the canisters. Liyuan provided the following conclusions:

ENTER GRAPHIC

Liyuan provided the following operational observations:

Liyuan indicated that acid-washing is being explored to regenerate the clumped iron. Although it is not conclusive, a correlation has been observed between the presence of bacteria and gas build up.

Rich Helferlich (Cercona) provided a brief overview of Cercona's efforts, performed in conjunction with ORNL, to identify candidate reactive media suitable for a permeable barriers demonstration at ORNL's Y-12 Plant. Rich indicate that the hydrogeology present at the Y-12 Plant is challenging. The soil is primarily clay with a system of conduits, which creates a number of discreet plumes (as opposed to a common wide plume). The pH of the area is variable, generally acidic ranging from 1-2 to 4-5. A system of tributaries, which typically have a pH of 4-5, flow into a main creek (Bear Creek) downgradient of the contaminant source. Multiple contaminants, including nitrates, uranium, and chlorinated solvents are present.

Rich indicated that batch studies were performed to act as a screening process for candidate media Candidate media tested include: a number of zero valent iron materials, a number of iron oxide zeolites with mixed absorbents, and a number of other absorbents from previous studies which had shown promise. Preliminary results indicate that:

Rich indicated that Cercona pellets, which the same composition as a number of the Cercona foams used in the batch studies, will be also be investigated. Rich explained that the physical characteristics of the pellets are more amenable to the Y-12 site. In addition to the investigation of the pellets, a number of other prospective media will be investigated as well.

Update on Activities at Lowry Air Force Base

Bob Edwards (Booz-Allen &: Hamilton) provided preliminary results of a F&G system installed at the Fly Ash Disposal site at Lowry AFB, Denver, CO. Sheet pilings, installed to a depth of 20 ft last winter, were used as the funnel and the gate, composed of 90 tons of Peerless iron, was 10 ft wide. Pea gravel was also emplaced immediately before and after the iron to homogenize groundwater flow into and out of the gate. Bob indicated that performance monitoring wells in the wall indicate that chlorinated reduction is occurring- all VOCs are lowered to detection limits after traveling through two feet of wall, as indicated in the table below. Bob noted that ethene and ethane have also been detected, which suggests that dechlorination is occurring.

Wall Cross
Section (ft)
PCE
(PPB)
TCE
(ppb)
cis-DCE
(ppb)
trans-DCE
(ppb)
VC
(ppb)

0

13.6

848

221

15.6

24.2

1

0.28

1.05

10.2

0.23

0.72

2

0.25

0.18

0.77

0.12

0.47

3.5

0.25

0.10

0.20

0.10

0.47

Bob indicated that the total cost of the F&G system is approximately $525K. Current cost projections suggest that the system needs to remain in operation for several years before it becomes cost effective and the cost per pound of chlorinated solvent removed will approach $24K after 10 years. This projection assumes that the iron is not replaced and that concentrations, degradation rates, and analytical costs are constant over this time. Bob suggested that as the design criteria become further refined, the overall project cost as well as the cost per pound of chlorinated solvents removed will be significantly reduced.

August 16, 1996

Discussion of Degradation Rates

Paul Tratnyek (Oregon Graduate Institute) discussed dechlorination degradation rates, why they differ between studies, and the degree to which they differ. Paul acknowledged Tim Johnson (Oregon Graduate Institute) and Michelle Scherer (Oregon Graduate Institute) and indicated that much of the presented material was developed by Tim and Michelle. Paul indicated that the Oregon Graduate Institute has compiled a catalog of references (journal articles, dissertations, books, etc.) on permeable barrier technologies and Paul noted that it is continually updated. There are currently 128 references. Paul asked that participants submit any missing references to him (see list of participants for contact information). Paul added that the list is available on the World Wide Web (Web) at http://cgr.ese.ogi.edu/ironrefs/, and also suggested that participants browse http://cgr.ese.ogi.edu/iron/, which provides an overview of the technology as well as a number of hotlinks to other permeable barrier Web sites.

In order to determine if independent laboratories were reporting similar results for observed rate constants (kobs) of chlorinated solvents, kobs was extracted from the literature and compared. Results published through November 1995 were used. Paul indicated that significant effort was needed to ensure that the compared kobs were reported in a similar fashion. In some situations, kobs was not reported, but Paul indicated that it was calculated where possible based upon reported data. Paul indicated that the kobs data, when plotted, appears to have no discernable trends. He noted that kobs data interpretation was difficult because of additional data was limited. Kobswas normalized to surface area, which lessened the kobs scatter, but Paul indicated that a discernable pattern was not evident. The figure to the left depicts ksa (kobs normalized to surface area). A number of other factors, such as pH, type of iron, initial concentration, etc., were investigated. Paul suggested that acid-washed iron may be have a higher rate constant, but cautioned that additional data is necessary. Paul did note, however, that the ksa(TCE) values are within an order of magnitude, except for one outlier. Paul suggested that this range should provide a benchmark forreported ksa(TCE) values. Paul noted that agreement is not as strong within a number of other compounds, but Paul suggested that the ranges suggested could be used as a guideline. Ksa was calculated using a correlation analysis and Paul indicated that the calculated ksa was comparable to existing data.

ENTER GRAPHIC...

Pathways and Products of Chlorinated Ethene Reduction by Metallic Iron

Dave Burris (Air Force's Armstrong Laboratory) presented an overview of the pathways and products of chlorinated ethenes reduced by metallic iron. He mentioned that the results presented today were developed in conjunction with associates at Johns Hopkins University, ARA, New Mexico Tech, Washington State University, and other collaborators. Batch studies were employed to investigate the reduction of chlorinated ethenes by cast-iron. The batch system was composed of the following: 5 g cast-iron, 0.1 g pyrite, 100 ml water, and 60 ml headspace. Dave explained that using headspace allowed for easier capture of degradation products. He indicated that a significant amount of the TCE is sorbed onto the iron, which is often unaccounted for in mass balance considerations. He suggested that other phases than just the aqueous phase need to be considered or a skewed pictorial may result. Transient conditions need to be identified and considered. Dave indicated that approximately 40 pore volumes are necessary to achieve steady-state. Dave stated that the primary types of reactions involved in the reductive process are:

The Fischer-Tropsch reactions account for the production of alkanes and alkenes and suggested that they account for other products as well. Possible pathways for reduction of chlorinated solvents are depicted below.

Dave provided the following summary comments:

Discussion of Reactive Media Choices and Mechanisms

Tim Sivavec (GE) provided an overview of efforts by GE to investigate reactive media and mechanisms. He indicated that GE's research goals are to:

The following table identifies work in-progress in the field of permeable barriers; Tim noted that it is not necessarily an inclusive listing.

Contaminant Treatment Media Work Location (Field Work)
Chlorinated
Solvents
Zero-valent iron, low-cost,
granular recycled iron,
Cercona foam/pellets
University of Waterloo (Yes); ETI (Yes);
EPA/Athens; Oregon Graduate Institute; GE
(Yes); DOE (Yes); Dupont (Yes); Monsanto; Air
Force/Tyndall AFB
Metallic couples, metal-
plated iron filings
Sweeney patents, Fe/Pd: ORNL, Univeristy of
Arizona (Yes); Fe/Cu: Monsanto, DuPont; Fe/Ni: University of Waterloo; Fe/Ni: GE
Iron sulfide minerals Pyrite, FeS2: Reinhard, Stanford Universtiy; pyrite
as a buffer: EPA/Athens; troilite, FeS, and other FexSy: GE
Other redox-active minerals Magnetite, ilmentite, chalcopyrite: GE;
chalcopyrite, CuFeS2: Michigan Tech Univ.;
Fe(II) - midofied magnetite: EAWAG
Colloidal iron Pacific Northwest Laboratory (Yes)
Reduction of aquifer
materials with dithionite
Pacific Northwest Laboratory
Granular irons plus sorbents GAC: University of Waterloo; GAC and
polymeric sorbents: GE
Sorption barriers Surfactant-modified clays: Tyndall AFB; zeolites:
New Mexico Tech
Cr(VI) Zero-valent iron University of Waterloo (Yes); EPA/Kerr Lab
(Yes); ORNL
Dithionite Pacific Northwest Laboratory (Yes)
H2S DOE, Sandia National Laboratory (Yes)
Uranium/Mill
Tailings
FeCl3-FeOOH DOE/Rust Geotech
Peat DOE/GJPO/Rust Geotech
H2S Wyoming
Surfactant-modified
zeolites
New Mexico Tech
PAHs Granular activated carbon University of Tubingen (Yes)
Radionuclides Zero-valent iron ORNL/LMES
Zeolites DOE/PNL/Hanford (Yes)
Pesticides Zero-valent iron EPA/Athens
Chlorinated
Aromatics
Fe/Pd ORNL
Low As/High
Phosphate
NaHCO3, Mg(OH)2, CaSO4 DuPont
Nitroaromatics Zero-valent iron; Fe(II)-
treated magnetite
Oregon Graduate Institute; EAWAG

Tim provided the following criteria for selection of an iron metal:

The following key parameters affecting dechlorination rates were identified:

Tim indicated that mineral precipitation, which leads to loss in iron zone permeability, is a leading cause of performance degradation. Mineral precipitation is due to: (1) plugging at the system entrance, and (2) loss of porosity throughout the iron zone. GE column flow tracer analysis has suggested that losses of porosity are typically 10% to 25%. Tim indicted that there is a linear relationship between the iron metal surface area and the TCE reduction rates. He provided a comparison of TCE reduction rates in batch and column studies performed by GE, as depicted in the following table.

Systen Water Type of Iron M2/L ks*(Lh-1s-2)
Batch DI

Peerless, 50 mesh to dust

180

1.9 x 10-4

Batch DI

Peerless, 20 mesh to dust

126

1.7 x 10-4

Batch DI

Peerless, 8 plus 50 mesh

-

1.3 x 10-4

Batch Site gw #1

Peerless, 8 plus 50 mesh

-

2.5 x 10-4

Column Site gw #1 Peerless, 8 plus 50 mesh

3810

1.2 x 10-4

Column Site gw #2 Peerless, 8 plus 50 mesh

4210

2.4 x 10-4

Column Site gw #2 Peerless, 8 plus 50 mesh

4760

5.7 x 10-4

* - represents surface-area normalized first order rate constant.

Tim also provided the following summary of GE's groundwater column treatability studies:

Column Media Pore Volumes
Treated
TCE Half-
life (h)
Effluent pH
100% granular iron

225

1.8

8.6

Granular iron: FeS (92:8)

400

2.0

7.8

100% granular FeS

160

0.9

7.3

Tim suggested that controlling the pH may allow Fe(II) migration downgradient, which could extend the reactive zone downgradient as well. GE has also performed work with bimetals, and Tim provided a brief overview of work in this field. He noted that a number of different sources for minerals are being investigated, and that the cost-effectiveness of the reactive media is important. (i.e., palladized iron exhibited a half-life 45x less than iron, but costs approximately 200x more per ton).

Overview of Monsanto's Bimetallic Reductive Dechlorination Studies

Robert Orth (Monsanto) provided an overview of Monsanto's iron and bimetallic reductive dechlorination studies. He indicated that the objectives of the studies are to: (1) examine mechanisms of dechlorination with iron and iron couples (bimetals); (2) determine what changes could be made to improve the rate of the reaction; and (3) obtain mass balance for products. In general, Robert indicated that an increase in the rate of corrosion results in an increase of the rate of dechlorination; this can be achieved by control of the pH, and use of galvanic couples (mixed metals or metals plated on the surface of the iron).

Robert provided the following overview of the experimental and analytical design:

Robert provided a brief overview of the corrosion process involved in the dechlorination of solvents by zero valent iron. He indicated that the rate determining step is dependent upon the catalytic properties of the iron surface. Any metal with higher reduction potential will accelerate the dehalogenation process. Robert indicated that bimetals increased the rate in the following order based upon Monsanto's laboratory studies: palladium > tin > silver > copper > gold > 99.2% iron > 99.999% iron. Robert provided the following data indicating the influence of surface coverage on rate:

Calculated Monolayer of
Copper of Iron Surface
Observed
Half-life (h)

0

111

<0.59

30

<7

37

<30

38

It appears that a combination of pathways are occurring. Robert indicated that the mechanism changes as the bimetallic changes. Robert provided the following summary statements:

Nickel-Iron as Reactive Material

John Vogan provided a brief overview of column studies performed by EnviroMetal Technologies, in collaboration with the University of Waterloo, to investigate the efficacy of nickel/iron to dechlorinate solvents. John indicated that nickel was observed only in the effluent of the first 10 pore volumes. ETI is investigating a number of nickel/iron alloys to identify the optimal material. John indicated that the majority of column study results are preliminary at this time, but are encouraging. In addition to recent column studies, an above-ground canister study, using nickel-plated iron, was initiated at a site in Wayne, NJ, during November 1994. John noted that it was difficult to obtain sufficient quantities of nickel-plated iron to perform the study. Approximately 2 tons of reactive media was used at $2-4K/ton. John noted that carbonate precipitate was a major concern and a number of measures were taken to minimize precipitation. In response to a participant's question regarding hydrogen gas build-up, John Vogan indicated that a sampling vent was used to release gas build-up within the NJ canister study.

Kinetics of TCE Reduction by Iron in the Presence of Soil

Alan Rabideau (SUNY Buffalo) provided an overview of efforts at SUNY Buffalo, with the support of DuPont, to investigate the kinetics of TCE reduction by iron in the presence of soil. Alan acknowledged the support of DuPont. The motivation for the studies were: (1) diffusive transport of dissolved contaminant in conventional soil/bentonite slurry walls is expected to produce breakthrough within the system design life, (2) greatly enhanced VOC degradation occurs in the presence of Fe0, and (3) a half-life of less than 1 year would significantly reduce VOC transformation in soil-bentonite walls. Alan indicated that batch and column studies were performed. The following batch study results were provided:

Regarding the column study, Alan indicated that hydrogen production was observed and that 3-7 weeks were required before steady-state conditions were achieved. TCE breakthrough was not seen in the column studies; however, Alan indicated that the majority of the column studies were only recently completed and that complete analysis has not been performed. Follow-up batch studies, however, have been completed. Alan reported the following results:

Alan identified a number of potential mechanisms to address the role of soil in the degradation of TCE:

Overview of Emplacement Technologies for Permeable Reactive Zones

Rich Landis (DuPont) provided an overview of emplacement technologies for permeable reactive zones.

Rich identified the following issues regarding emplacement techniques:

Rich identified the following path forward for DuPont's evaluation of emplacement technologies:

Mineral Precipitation and Hydraulic Issues of Permeable Reactive Zones

Pat MacKenzie (GE) discussed mineral precipitation and hydraulic issues as they pertain to permeable reactive zones. Pat indicated that hydraulic losses are due to either plugging or porosity losses. Porosity losses are due to mineral precipitates, such as FeCO3 and CaCO3, and are typically found throughout the length of a column, canister, or in-situ treatment zone. Plugging is typified by an orange/brown solidified mass and is caused by the cementing of particles by ferric (oxy)hydroxides. Plugging usually causes rapid pressure rise, and is most commonly found near the inlet port of a column or canister. Plugging may divert groundwater flow around an in-situ treatment zone. Pat indicated that high DO levels contribute significantly to precipitation, and must be accounted for in either an in-situ or ex-situ study. GE is investigating the use of oxygen scavengers to reduce DO levels prior to contact with the reactive media The oxygen scavenger is typically emplaced as a layer immediately in front of the reactive media, and Pat indicated that GE is investigating use of removable cassettes, which may then be replaced if necessary.

Pat provided additional details regarding mineral precipitation in in-situ treatment zones, that it is caused by:

Pat explained that the impact of the precipitation is as follows:

Pat indicated that GE performed column studies to measure porosity losses over time. She noted that a nonsorbing tracer was used to determine porosity losses and that a 10% loss in porosity was seen after 382 pore volumes, equivalent to 9.8 years in real-time. Pat indicated that a small porosity loss can have a significant impact on zone permeability. Because of this, Pat suggested that reactivity/porosity losses should be carefully monitored at the entrance of an in-situ treatment zone.

General Discussion

Dale Schultz initiated a general discussion of the earlier presentations and of issues relevant to the Permeable Barriers Action Team. Dale suggested that the Action Team identify needs to further permeable barriers as a remediation technology. Don Marcus (EMCON) felt that bimetals are promising, and asked if any long term column studies had been performed. John Vogan was unaware of any bimetal column studies where greater than 200 pore volumes were used, but Tim Sivavec mentioned that GE is performing a Ni/Fe column study and expects that 500 pore volumes will be used.

Tim Sivavec suggested that sulfur compounds seem to negatively impact the effectiveness of bimetals. John Vogan indicated that he has experienced biofouling, but did not observe indications of increased sulfate reducing microbial populations, which he did note was unusual. Pat MacKenzie indicated that GE has seen a significant amount of microbial activity in groundwater, but has not analyzed the effluent. John indicated that this phenomenon will be investigated more closely in the future. In response to a participant's question, John suggested that several months are necessary before a field system stabilizes to a steady-state. He noted that an in-flux of contaminated groundwater into the reactive barrier often occurs during construction, which adds to the time needed to achieve steady-state. Pat MacKenzie suggested that 2 months are sufficient to flush the field system. Dale Schultz suggested that it is dependent upon groundwater velocity and other key parameters.

Scott Warner asked if any Action Team members had performed column studies with a geometry more similar to field systems. Pat MacKenzie indicated that GE considered non-circular columns, but they were difficult to engineer. Stan Morrison (Rust Geotech) indicated that a "tank" system was developed by DOE and Rust Geotech to better mimic field conditions, but the system was difficult to operate. Pat MacKenzie noted that a reliable method to collect and transfer groundwater from the subsurface to the laboratory without altering its characteristics has not yet been identified. Similarly, a participant suggested that there are a number of unresolved issues regarding engineering scale-up from the laboratory to a field system. Scott Warner felt that engineering and hydraulic conditions are often considered a lower priority than the degradation chemistry. Rich Landis noted that there is often limited hydraulic data to engineer a field system. A participant suggested that performance monitoring is more critical if an innovative emplacement technique is used as the integrity of the wall may be in question. Dale Schultz agreed that performance monitoring is very important in thin walls, such as those created by high-pressure jetting or tremie tubes.

Concluding Remarks

Dale Schultz thanked presenters and participants and stated that a significant amount of information was shared during the meeting. Dale noted that dechlorination chemistry has been a leading topic of the day's presentations and a number of participants felt that follow-up presentations would be of interest at a future meeting. Additional participants suggested that a discussion of hydraulics/scale-up from the laboratory to the field would be of interest. The Action Team agreed to meet in Denver, CO, on December 11-12, 1996. Bob Stone (EPA\Region VIII) noted that the U.S. Geological Survey is leading a F&G field demonstration outside of Denver, CO, and suggested that the Action Team could visit the demonstration at the next meeting. Dale asked participants to provide any additional topics for the future meetings so that they may be considered.

The following action items were identified during the meeting:

Matt Turner:

Chuck Reeter, in coordination with Scott Warner:

Ed Marchand will provide 2 copies of slides and overheads of the Lowry AFB pilot installation and results (including economics).

John Vogan will provide 2 copies of slides and overheads of additional pilots with which ETI has been involved, and will also provide cost and design information.

Mark Searles will provide Steve McCutcheon with a monthly status report on each of the Action Items.


RTDF Permeable Barriers Action Team Meeting Participants

Mr. William Baugman
Cummings Riter Consultants
339 Haymaker Road
Parkway Bldg., Suite 201
Monroeville, PA 15146
Tel: (412) 373-5240
Fax: (412) 373-5242
E-mail: crc@nb.net

Dr. Robert Bowman
Department of Geoscience
New Mexico Tech
Socorro, New Mexico 87801
Tel: (505) 835-5634
Fax: (505) 835-6436
E-mail: bowman@nmt.edu

Dr. David Burris
U.S. Air Force
Armstrong Laboratory
AL/EQW
139 Barnes Drive, Suite 2
Tyndall AFB, FL 32403-5323
Tel: (904) 283-6035
Fax: (904) 283-6090
E-mail: david_burris@ccmail.aleq.tyndall.af.mil

Ms. Darcy Byrne
MSE-TA Inc.
P.O. Box 4078
Butte, MT 59702
Tel: (406) 494 7279
Fax: (406) 494-7230
E-mail: dbyme@buttenet.com

Mr. Kirk Cantrell
Battelle, Pacific Northwest Laboratories
P.O. Box 999
Richland, WA 99352
Tel: (509) 376-2136
Fax: (509) 376-5368
E-mail: kj_cantrell@pnl.gov

Ms. Sandy Clavell
Walcoff & Associates
2001 Beauregard St.
Suite 800
Alexandria, VA 22314
Tel: (703) 578-6152
Fax: (703) 578-5746
E-mail: sclavell@erols.com

Mr. Bob Edwards
Booz Allen & Hamilton
300 Convent St., Suite 1250
San Antonio, TX 78205
Tel: (210) 244-4253
Fax: (210) 244-4206
E-mail: edwardsb@bah.com

Dr. Steven Fann
Naval Facilities Engineering Southern Command
1100 23rd Ave.
Port Hueneme, CA 93043
Tel: (805) 982-1263
Fax: (805) 982-4304
E-mail: sfann@nfesc.navy.mil

Ms. Stephanie Fiorenza
Rice University
P.O. Box 1892, MS 316
Houston, TX 77251
Tel: (713) 527-8101 ext. 3338
Fax: (713) 285-5948
E-mail: fiorenza@rice.edu

Dr. Arun Gavaskar
Battelle
505 King Avenue
Columbus, OH 43201
Tel: (614) 424-3403
Fax: (614) 424-3667
E-mail: gavaskar@battelle.org

Mr. Will Goldberg
MSE, Inc.
P.O. Box 4078
Butte, MT 59702
Tel: (406) 494-7443
Fax: (406) 494-7230
E-mail: goldberg@buttenet.com

Dr. Neeraj Gupta
Battelle
505 King Avenue
Columbus, OH 43201
Tel: (614) 424-3820
Fax: (614) 424-3667
E-mail: gupta@battelle.org

Mr. Rich Helferich
Cercona, Inc.
5911 Wolf Creek Pike
Dayton, Ohio 45426
Tel: (937) 854-9860
Fax: (937) 854-9861
E-mail: rhelferich@coax.net

Mr. Grant Hocking
Golder applied Technologies Inc.
3730 Chamblee Tucker Rd.
Atlanta, GA 30341
Tel: (770) 496-1893
Fax: (770) 934-9476
E-mail: ghocking@golder.com

Dr. Ron Holser
National Research Council
Environmental Research Laboratory
U.S. Environmental Protection Agency
960 College Station Road
Athens, GA 30605-2700
Tel: (706) 355-8236
Fax: (706) 355-8202
E-mail: holser.ron@epamail.epa.gov

Mr. Brad Job
Regional Water Quality Control Board
2101 Webster St., Ste 500
Oakland, CA 94612
Tel: (510) 286-1382
Fax: (510) 286-1380
E-mail: job@ccnet.com

Dr. Rich Landis
DuPont Specialty Chemicals
Barley Mill Plaza/27-2288
P.O. Box 80027
Wilmington, DE 19880-0027
Tel: (302) 892-7452
Fax: (302) 892-7641
E-mail: landisrc@al.engg.umc.dupont.com

M. Liyuan Liang
Oak Ridge National Laboratory
P.O. Box 2008
Oak Ridge, TN 37834-6038
Tel: (423) 241-4748
Fax: (423) 576-8646
E-mail: liangl@ornl.gov

Mr. Gus Lo
AFCEE/ERC
3207 North Road
Brooks AFB, TX 78235
Tel: (210) 536-5294
Fax: (210) 536-5989
E-mail: glo@afcexbl.brooks.af.mil

Dr. Patricia MacKenzie
General Electric CRD
Building K1, Room 5A47
P.O. Box 8
1 River Road
Schenectady, NY 12301
Tel: (518) 387-6831
Fax: (518) 387-5592
E-mail: mackenzie@crd.ge.com

Mr. Steve Mangion
U.S. Environmental Protection Agency
401 M Street, SW
Washington D.C., 20460
Tel: (202) 260-1084
Pax: (202) 260-0106
E-mail: mangion.stephen@epamail.epagov

Major Ed Marchand
AFCEE/ERT
3207 North Road
Brooks AFB, IX 78235
Tel: (210) 536-4364
Fax: (210) 536-4330
E-mail: emarchan@afceebl.brooks.af.mil

Mr. Donald Marcus
Senior Supervising, Geologist
EMCON Associates
3300 North San Fernando Blvd.
Burbank, CA 91504
Tel: (818) 841-1160 (ext. 337)
Fax: (818) 846-9280
E-mail: dmarcus@emconinc.com

Mr. Jeff Marqusee
Department of Defense
ODUSD (ES)
3400 Pentagon
Washington, DC 20301-3400
Tel: (703) 614-3090
Fax: (703) 693-2659
E-mail: marqusj@alq.osd.mil

Dr. Steven McCutcheon
National Exposure Research Laboratory
U.S. Environmental Protection Agency
960 College Station Road
Athens, GA 30605-2700
Tel: (706) 355-8235
Fax: (706) 355-8202
E-mail: mccutcheon.steven@epamail.epa.gov

Dr. Stan Morrison
In-Situ Barriers
524 30 Road, Suite 5A
Grand Junction, CO 81504
Tel: (970) 434-4481
Fax: (970) 434-4483
E-mail: stan@wic.net

Mr. Mark Noll
Applied Research Associates, Inc.
P.O. Box 02063
Bldg. 909, Arnold St. Ext.
Dover AFB, DE 19902
Tel: (302) 677-4147
Fax: (302) 677-4100
E-mail: mnoll@ara.com

Ms. Mary North-Abbott
MSE Technology Applications, Inc.
P.O. Box 4078
Butte, MT 59702
Tel: (406) 494-7279
Fax: (406) 494-7230
E-mail: northabb@buttenet.com

Major Jeff Ogden
Inspector General Office
Department of Defense
400 Army Navy Drive
Arlington, VA 22202
Tel: (703) 604-9408
Fax: (703) 604-9204
E-mail: jogden@dodig.osd.mil

Dr. Bob Olfenbuttel
Battelle
505 King Avenue
Columbus, OH 43201
Tel: (614) 424-4827
Fax: (614) 424-3667
E-mail: olfenbur@battelle.org

Dr. Robert Orth
Monsanto Company
800 North Lindbergh Blvd.
St. Louis, MO 63167
Tel: (314) 694-1271
Fax: (314) 694-1531
E-mail: raorth@ccmail.monsanto.com

Second Lieutenant Dennis O'Sullivan
U. S. Air Force
Armstrong Laboratory (AL/EQW)
139 Barnes Drive, Suite 2
Tyndall AFB, FL 32403-5323
Tel: (904) 283-6239
Fax: (904) 283-6064
E-mail: dennis_osullivan@ccmail.aleq.tyndall.af.mil

Ms. Carey Peabody
Erler & Kalinowski, Inc.
1730 S. Amphlett Blvd., Ste 320
San Mateo, CA 94402
Tel: (415)578-1172
Fax: (415) 655-4964
E-mail: cpeabody@1x.netcom.com

Dr. Robert Puls
National Risk Management Research Laboratory
U.S. Environmental Protection Agency
P.O. Box 1198
Ada, OK 74820
Tel: (405) 436-8543
Fax: (405) 436-8706
E-mail: puls@ad3100.ada.epa.gov

Mr. Kenneth Quinn
Montgomery Watson
1 Science Ct.
Madison, WI 53711
Tel: (608) 231-4747
Fax: (608) 231 4777
E-mail: kenneth.quinn@us.mw.com

Mr. Alan Rabideau
SUNY Buffalo
Department of Civil Engineering
SUNY at Buffalo
Buffalo, NY 14260
Tel: (716) 645-2114
Fax: (716) 645-3667
E-mail: rebideau@eng.buffalo.edu

Mr. Chuck Reeter
Naval Facilities Engineering Southern Command
1100 23rd Ave.
Port Hueneme, CA 93043
Tel: (805) 982-1808
Fax: (805) 982-4304
E-mail: creeter@nfesc.navy.mil

Mr. Peter Russell
ICI Austrailia
P.O. Box 4311
Melbourne, Austrailia 3001
Tel: 03 665-7635
Fax: 03 665-7929

Dr. Bruce Sass
Battelle
505 King Avenue
Columbus, OH 43201
Tel: (614) 424-6315
Fax: (614) 424-3667
E-mail: sassb@battelle.org

Mr. Michael Schnarr
Harding Lawson Assoc.
707 17th St., Ste. 2400
Denver, CO 80202
Tel: (303) 293-6092
Fax: (303) 292-5411
E-mail: mschnarr@harding.com

Dr. Dale Schultz
DuPont
Glasgow Site, Building 300
Rt. 896
P.O. Box 6101
Newark, DE 19714
Tel: (302) 451-9871
Fax: (302) 451-9138
E-mail: schultds@al.esvax.umc.dupont.com

Mr. Mark Searles
The Scientific Consulting Group, Inc.
656 Quince Orchard Road
Suite 210
Gaithersburg, MD 20878-1409
Tel: (301) 670-4990
Fax: (301) 670-3815
E-mail: searlesm@cpcug.org

Dr. Timothy Sivavec
General Electric CRD
1 River Road
Building K1, Room 5A45
Schenectady, NY 12301
Tel: (518) 387-7677
Fax: (518) 387-5592
E-mail: sivavec@crd.ge.com

Mr. Chris Smith
Lockhead Martin
Y-12 Plant, MS8247, BLD 9983-AH
Oak Ridge, TN 37831
Tel: (615) 576-6526
Fax: (615) 576-3808

Mr. Bob Starr
Idaho National Engineering Laboratory
P.O. Box 1625, Mail Stop 2107
Idaho Falls, lD 83415-2107
Tel: (208) 526-5687
Fax: (208) 526-0875
E-mail: starr@inel.gov

Mr. Richard Steimle
Technology Innovation Office (OS-11OW)
U.S. Environmental Protection Agency
401 Main Street, SW
Washington, DC 20460
Tel: (703) 603-7195
Fax: (703) 603-9135
E-mail: steimle.rich@epamail.epa.gov

Captain Jeff Stinson
U.S. Air Force
Armstrong Laboratory (AL/EQW)
139 Barnes Drive, Suite 2
Tyndall AFB, FL 32403-5323
Tel: (904) 283-6254
Fax: (904) 283-6286
E-mail: jeff_stinson@ccmail.aleq.tyndall.af.mil

Mr. Robert Stone
EPA/Region VIII
8EPR-PS
999 18th Street
Denver, CO 80202-2466
Tel: (303) 312-6777
Fax: (303) 312-6065
E-mail: stone.robert@epamail.epa.gov

Mr. Brad A. Schwartzman
Southern Division, Naval Facilities Engineering Command
P.O. Box 190010
N. Charleston, SC 29419-9010
Tel: (803) 820-7358
Fax: (803) 820-5563
E-mail: baschwartzman@efdsouth.navfac.navy.mil

Dr. Paul G. Tratnyek
Oregon Graduate Institute
Department of Environmental Science and Engineering
P.O. Box 91000
Portland, Oregon 97291-1000
Tel: (503) 690-1023
Fax: (503) 690-1273
E-mail: tratnyek@ese.ogi.edu

Mr. John Vogan
EnviroMetal Technologies, Inc.
42 Arrow Road
Guelph, Ontario, Canada, N1K 1S6
Tel: (519) 824-0432
Fax: (519) 763-2378
E-mail: eti@beak.com

Mr. Scott Warner
Geomatrix Consultants, Inc.
100 Pine Street, 10th Floor
San Francisco, CA 94111
Tel: (415) 434-9400
Fax: (415) 434-1365
E-mail: swarner@geomatrix.com

Mr. Stephen White
USACE
12565 West Center Road
Omaha, NE 68144
Tel: (402) 697-2660
Fax: (402) 697-2674
E-mail: stephen.j.white@usace.army.mil

Mr. Randy Wolf
U.S. Air Force
Armstrong Laboratory (AL/EQW)
139 Barnes Drive, Suite 2
Tyndall AFB, FL 32403-5323
Tel: (904) 283-6187
Fax: (904) 283-6286
E-mail: randy_wolf@ccmail.aleq.tyndall.af.mil

Mr. Darrin Wray
7274 Wardleigh Road
Hill AFB, UT 54056-5137
Tel: (801) 777-8790
Fax: (801) 777-4306
E-mail: wrayd@hillwpos.hill.af.mil

Additional RTDF Permeable Barriers Action Team Members

Dr. Jim Anderson
Department of Chemistry
University of Georgia
Athens, GA 30602
Tel: (706) 542-2626
Fax: (706) 542-9454

Mr. Frank Anderson
Martin Marietta Energy Systems
Portsmouth Gaseous Diffusion Plant
P.O. Box 628, MS 7615
Piketon, OH 45661
Tel: (614) 897-2241
Fax: (614) 897-6273

Dr. Martin Bell
ICI Chemicals & Polymers, Ltd.
P.O. Box 13
The Heath, Runcorn
Cheshire, UK WA7 4QF
Tel: (011) 44-1928-517-875
Fax: (011) 44-1928-581-204
E-mail: martin.bell@ukrnh72.c+p.ici.tmailuk.sprint.com

Dr. David Blowes
Institute for Groundwater Research
University of Waterloo
Waterloo, Ontario, Canada N2L 3G1
Tel: (519) 888-4878
Fax: (519) 746-5644

Ms. Beverly Campbell
The Scientific Consulting Group, Inc.
656 Quince Orchard Road
Suite 210
Gaithersburg, MD 20878-1409
Tel: (301) 670-4990
Fax: (301) 670-3815
E-mail: scginc@millkern.com

Mr. Cliff Casey
Southern Division
Naval Facilities Engineering Command
2155 Eagle Drive
N. Charleston, SC 29411
Tel: (803) 820-5561
Fax: (803) 820-7465

Mr. Skip Chamberlain
DOE-EM-54, CL
19920 Germantown Road
Germantown, MD 20874
Tel: (301) 903-7248
Fax: (301) 903-7234

Mr. Dean Chartrand
IBM
9600 Godwin Drive
Manassas, VA 22110
Tel: (703) 367-1364
Fax: (703) 367-2319

Dr. Chien Chen
USEPA (MS-104)
2890 Woodbridge Avenue, Bldg 10
Edison, NJ 08837
Tel: (908) 906-6985
Fax: (908) 321-6640
E-mail: chen.chien@epamail.epa.gov

Mr. Mark Cipollone
TAI, Inc.
Environmental Research Laboratory
U.S. Environmental Protection Agency
960 College Station Road
Athens, GA 30605-2700
Tel: (706) 546-3189
Fax: (706) 546-3636
E-mail: cipollone@sunchem.chem.uga.edu

Mr. Richard Conway, P.E.
Senior Corp Fellow
Union Carbide Corp (770-342)
3200 Kanawha Turnpike
P.O. Box 8361
South Charleston, WV 25303
Tel: (304) 747-4016
Fax: (304) 747-5430

Dr. Jim A. Davis
USGS MS-465
345 Middlefield
Mineral Park, CA 94025
Tel: (415) 329-4484
Fax: (415) 329-4327

Dr. Tom Early
Environmental Sciences Division
Oak Ridge National Laboratory
P.O. Box 2008
Oak Ridge, TN 37831-6317
Tel: (615) 576-2103
Fax: (615) 574-7420
E-mail: eot@ornl.gov

Dr. David Ellis
DuPont Specialty Chemicals
Barley Mill Plaza 27-2284
P.O. Box 80027
Wilmington, DE 19880-0027
Tel: (302) 892-7445
Fax: (302) 892-7641
E-mail: ellisde@al.csoc.dnet.com

Dr. John Fruchter
Pacific Northwest Laboratory
Battelle Boulevard
Richland, WA 99352
Tel: (509) 376-3937
Fax: (509) 376-5368
E-mail: js_fruchter@pnl.gov

Dr. Bob Gillham
Institute for Groundwater Research
University of Waterloo
Waterloo, Ontario, Canada N2L 3G1
Tel: (519) 888-4567
Fax: (519) 746-5644

Mr. Will Goldberg
MSE, Inc.
P.O. Box 4078
Butte, MT 59702
Tel: (406) 494-7443
Fax: (406) 494-7230
E-mail: goldberg@buttenet.com

Dr. Neil Gray
Zeneca BioProducts
2101 Hadwen Road
Missassauga, Ontario, Canada LSK 2L3
Tel: (905) 823-7237
Fax: (905) 823-0047

Dr. Baohua Gu
Environmental Engineering
Environmental Sciences Division
Oak Ridge National Laboratory
P.O. Box 2008, MS 6036
Tel: (423) 574-7286
Fax: (423) 576-8543
E-mail: b26@ornl.gov

Dr. Johnson Haas
National Research Center
Environmental Research Laboratory
U.S. Environmental Protection Agency
960 College Station Road
Athens, GA 30605-2700
Tel: (706) 546-3560
Fax: (706) 546-3636
E-mail: jhaas@athens.ath.epa.gov

Mr. Joseph Hailer
Waste Policy Institute
9350 S. Presa
San Antonio, TX 78223
Tel: (210) 633-1308
Fax: (210) 633-0983
E-mail: joe_hailer@wpi.org

Dr. Kirk Hatfield
Dept. Civil Engineering
University of Florida
345 Weil Hall
Gainesville, FL 32611
Tel: (904) 846-0606
E-mail: khatfce.ufl.edu

Mr. Conrad Ingram
Clark Atlanta University
223 James P. Brawley Dr.
Atlanta, GA 30314
Tel: (404) 880-6737 ext. 3166
Fax: (404) 853-0048
E-mail: cingram@cau.edu

Mr. Peter Jeffers
U.S. Environmental Protection Agency
960 College Station Rd.
Athens, GA 30605

Dr. Erica Jonlin
Biochemist
BDM Federal, Inc.
555 Quince Orchard Road, Suite 400
Gaithersburg, MD 20878
Tel: (301) 212-6224
Fax: (301) 212-6250

Mr. Mark Kaminski
Delta Research Corporation
1501 Merchants Way
Niceville, FL 32578
Tel: (904) 897-5380
Fax: (904) 897-5388
E-mail: mkaminsk@deltabtg.com

Mr. Joe King
U.S. Army Environmental Center
Aberdeen Proving Grounds, MD 21010-5401
Tel: (410) 671-1535
Fax: (410) 671-1548

Dr. Gary Klecka
Health and Environmental Sciences
Dow Chemical Company
Building 1803
Midland, MI 48674
Tel: (517) 636-3227
Fax: (517) 638-9305
E-mail: usdowq8z@ibmmail.com

Mr. George Korfiatis
Stevens Institute of Technology
Tel: (201) 216-5348
Fax: (201) 216-8303

Mr. John Koutsandreas
DOE-EM-54
12800 Middlebrook Road
Germantown, MD 20874
Tel: (301) 903-1278
E-mail: john.koutsandreas@em doe.gov

Mr. Gus Lo
AFCEE/ERC
3207 North Road
Brooks AFB, TX 78235
Tel: (210) 536-5294
Fax: (210) 536-5989
E-mail: glo@afcexbl.brooks.af.mil

Mr. Tom Malloy
MSE-Technology Applications, Inc.
P.O. Box 4078
Butte, MT 59701
Tel: (406) 494-7202
Fax: (406) 494-7230
E-mail: tommalloy@buttenet.com

Dr. Dianne Marozas
Sandia National Laboratory
Mail Stop-0719
Albuquerque, NM 87185-0719
Tel: (505) 844-5504
Fax: (505) 844-0543
E-mail: dcmaroz@sandia.gov

Ms. Lynn McCloskey
Western Environmental Technology Center, Inc.
P.O. Box 4078
Butte, MT 59701
Tel: (406) 494-7371
Fax: (406) 494-7230

Mr. Peter McMahon
U.S. Geological Services
Water Research Division
Colorado District
Denver, CO 80225
Tel: (303) 236-4882 x286
Fax: (303) 236-4912
E-mail: pmcmahon@usgs.gov

Ms. Alanna Mitchell
WALCOFF Associates
2001 N. Beauregard St.
Suite 800
Alexandria, VA 22311
Tel: (703) 578-8222
Fax: (703) 578-0527
E-mail: amitchel@walcoff.com

Ms. Jennifer Nelson
Manager, Environmental Restoration Technologies Department
Sandia National Laboratories
P.O. Box 5800
Department 06621/MSO719
Albuquerque, NM 87185-0719
Tel: (505) 845-8345
Fax: (505) 844-0543

Ms. Stephanie O'Hannesin
Waterloo Centre for Groundwater Research
University of Waterloo
Waterloo, Ontario Canada N2L 3G1
Tel: (519) 885-1211 ext. 3159

Dr. Ian T. Osgerby
U.S. Army Corps of Engineers
424 Trapelo Road
Waltham, MN
Tel: (617) 647-8631
Fax: (617) 647-8639
E-mail: ian.t.osgerb@nedOl.usace.arrny.mil

Mr. Philip Palmer, P.E.
DuPont Specialty Chemicals
Corporate Remediation
Barley Mill Plaza, 27-2280
P.O. Box 80027
Wilmington, DE 19880
Tel: (302) 892-7456
Fax: (302) 892-7641
E-mail: palmerpa@csoc.dnet.dupont.com

Mr. Anthony V. Palumbo
Environmental Sciences Division
P.O. Box 2008
Oak Ridge National Laboratory
Oak Ridge, TN 37831 6038
Tel: (423) 576-8002
Fax: (423) 574-0765
E-mail: avp@ornl.gov

Mr. Greg Penland
Southern Division Naval Facilities Engineering Command
2155 Eagle Drive
N. Charleston, SC 29411
Tel: (803) 743-0561

Mr. Edward Pesce
AFCEE
Masachusetts Military Reservation
Headquarters ASEE-MMR
322 East Inner Road
Otis AFB, MA 02542
Tel: (508) 968-4676
Fax: (508) 968-4673
E-mail: epesce@mafmh.ang.af.mil

Mr. Gene Peters
Clean Sites, Inc.
1199 North Fairfax Street
Suite 400
Alexandria, VA 22314
Tel: (703) 739- 1271
Fax: (703) 548-8773
E-mail: user445569@aol.com

Mr. Mark Phifer
Environmental Sciences Section
Westinghouse Savannah River Company
Savannah River Site
Building 773-42A
Road 1
Aiken, SC 29808
Tel: (803) 725-5222
Fax: (803) 725-7673
E-mail: mark.phifer@srs.gov

Dr. Will Robertson
Institute for Groundwater Research
University of Waterloo
Waterloo, Ontario, Canada N2L 3G1
Tel: (519) 888-4567
Fax: (519) 746-5644

Mr. Michael Royer
Technical Support Branch
U.S. Environmental Protection Agency
Building 10 (MS-104)
2890 Woodbridge Avenue
Edison, NJ 08837-3679
Tel: (908) 321-6633
Fax: (908) 321-6640
E-mail: royer.michael@epamail.epa.gov

Mr. H.G. Sanjay
Research Engineer
ARCTECH, Inc.
14100 Park Meadow Drive #210
Chantilly, VA 20151
E-mail: envrtech@arctech.com

Mr. Bob Schenck
Cercona, Inc.
911 Wolf Creek Pike
Dayton, Ohio 45426
Tel: (937) 854-9860
Fax: (937) 854-9861

Mr. Richard Scheper
Fermco, Inc.
P.O. Box 538704
Cincinnati, OH 45253
Tel: (513) 648-6145
Fax: (513) 648-6941

Mr. Steve Shikaze
Institute for Groundwater Research
University of Waterloo
Waterloo, Ontario, Canada N2L 3G1
Tel: (519) 888-4567
Fax: (519) 746-5644

Mr. Stephen Shoemaker
E.I. DuPont de Nemours & Company Inc.
Corporate Remediation
140 Cypress Station Drive, Suite 135
Houston, TX 77090
Tel: (713) 586-2513
Fax: (713) 586-2504
E-mail: shoemash@al.bmoa.umc.dupont.com

Dr. David Smyth
Institute for Groundwater Research
University of Waterloo
Waterloo, Ontario, Canada N2L 3G1
Tel: (519) 888-4567 ext. 2899
Fax: (519) 746-5644
E-mail: dsmyth@sciborg.uwaterloo.ca

Mr. Gregg Somermeyer, P.E.
Principal Engineer
SECOR International Incorporated
Tel: (970) 226-4040
Fax: (970) 226-4099
E-mail: gsomerme@secor.com

Dr. Daniel Stone
OO-ALC/EM
7274 Wardleigh Road
Hill AFB, UT 84056-5137
Tel: (801) 777-6918
Fax: (801) 777-7306

Mr. Marland Thurston
Delta Research Corporation
1501 Merchants Way
Niceville, FL 32578
Tel: (904) 897-5380
Fax: (904) 897-5388
E-mail: mthurston@deltabtg.com

Mr. Chuck Turick
Idaho National Engineering Laboratory
P.O. Box 1625
Idaho Falls, ID 83415
Tel: (208) 526-1876
Fax: (208) 526-0828

Mr. Harry Van den Berg
EMCON Associates
3300 North San Fernando Blvd.
Burbank, CA 91504
Tel: (818) 841-1160 (ext. 327)
Fax: (818) 846-9280

Dr. Joyce Whang
DuPont Experimental Station
P.O. Box 80304
Wilmington, DE 19880-0304
Tel: (302) 695-1793
Fax: (302) 695-4414
E-mail: whangjm@esvax.dnet.dupont.com

Mr. Steve Winters
Oak Ridge National Laboratory
U.S. Department of Energy
P.O. Box 2008
Bldg. 1505, Room 173
Oak Ridge, TN 37831-6035
Tel: (423) 576-3465
E-mail: svq@ornl.gov

Dr. Lee Wolfe
Environmental Research Laboratory
U.S. Environmental Protection Agency
960 College Station Road
Athens, GA 30605-2700
Tel: (706) 546-3429
Fax: (706) 546-3636
E-mail: wolfe.lee@epamail.epa.gov