vvEPA
                        United States
                        Environmental Protection
                        Agency
                        Research and Development (481)
                        Solid Waste and
                        Emergency Response (5102G)
EPA542-F-97-012b
November 1997
Bioremediation of Chlorinated
Solvents  Consortium
       RTDF
   Remediation Technologies
     Development Forum
                           _
'Permeable Reactive     x *1
                            ^ •*
Barriers[ActionTeam ,   ;'*

IINERT Soil-Metals Action^
fTeani

Sediments Remediation
Action Team ~s -*, -i     >-.,"'
                           >i
Iri: Situ Flushing Action   'f,:
Team
   ""• ,  - -         "T'\   ,  *',
Phytoremediation of
prganics Action Team   ,  ;
             What Is the Bioremediation

             Consortium?

             The Bioremediation of Chlorinated Solvents Consortium is one of seven
             Action Teams of the Remediation Technologies Development Forum (RTDF).
             The RTDF was created in 1992 by the U.S. Environmental Protection Agency
             (EPA) to foster collaboration between the public and private sectors in devel-
             oping innovative solutions , to  mutual hazardous waste problems. The
             Bioremediation Consortium was established in May 1993, when representa-
             tives from various companies, universities, the EPA, the Department of
             Defense (DOD),  and the Department of Energy (DOE) met to discuss their
             shared interest in developing in situ bioremediation technologies to degrade
             chlorinated solvents in soils and ground water. As a result of that first meeting,
             the industrial partners of the Bioremediation Consortium—DuPont, Dow,
             General  Electric, Monsanto, Zeneca, and Ciba-Geigy—signed a research
             agreement in September 1994. Agreements then were negotiated with EPA,
             the Air Force, and DOE to facilitate collaboration between the public and
             private sectors on the planned research projects. Two additional companies,
             Beak International and ICI Americas, joined the Bioremediation Consortium
             in Spring 1996.

             What Is the Problem of Concern?
             Chlorinated solvents are the rriost common contaminants resulting from indus-
             trial and government operations. Used as solvents and degreasers, they are typi-
             cally found in the soils and ground water adjacent to manufacturing, mainte-
             nance, and service installations around the world. Although complete degrada-
             tion of chlorinated solvents to harmless end products is known to occur, a better
             understanding of  how to predict and manage these degradation processes is
             needed to ensure their use as cost-effective, practical solutions.

             What Is the Mission of the

             Bioremediation Consortium?
             The mission of the RTDF Bioremediation Consortium is to accelerate the
             development of the most cost-effective in  situ bioremediation processes for
             degrading chlorinated solvents. To accomplish this mission, the Consortium
             members jointly participate in the research, development, demonstration, and
             evaluation efforts necessary to achieve public and regulatory acceptance of
             these biological processes. In addition, the data generated and experience
             gained by the Consortium in conducting field studies with these processes will
             be used to develop guidelines for their use at other contaminated sites.

-------
              Comctabolic Bioventing
    Soli Gas
    Monitor
                          Low Rate Air and
                        Cometabolite Injection
 Ground Water
Monitoring Well
Soil Gas
Monitor
What Processes  Will Be

Studied?
The  Consortium focuses on three in situ bioremediation
processes: cornetabolic  bioventing (for  treatment in the
vadose zone), intrinsic bioremediation (for treatment of the
bulk of a plume), and accelerated anaerobic biodegradation
(for treatment of more concentrated areas of a plume). These
technologies are environmentally friendly;  they  cause
minimal disturbance to the site as they require few surface
structures. They also involve less  cost than conventional
pumping and treating. The Bioremediation Consortium initi-
ated  Phase I field tests of the three processes at Dover Air
Force  Base  (AFB)  in Dover, Delaware, in  early 1995.
Planning is underway to conduct Phase n field studies for
each of the processes at another site.
Conietabolie Bioventing. Laboratory studies have shown
that aerobic  degradation of trichloroethene (TCE) in soils
occurs most easily in the presence of a cometabolite, such
as toluene, propane,  or methane. Cornetabolic bioventing
uses a technique,  similar to methods  currently used in
bioventing technology, to efficiently deliver oxygen and a
cometabolite to the vadose zone in order to remediate TCE.
This technology appears to have great promise. The objec-
tive of the RTDF cornetabolic bioventing study is to develop
a cost-effective process that  promotes the cornetabolic
bioremediation of TCE and other chlorinated solvents. The
Consortium  initiated the Phase I Cornetabolic Bioventing
Study- at Dover AFB, where TCE is present in sandy soil.
Intrinsic  Bioremediation.  Intrinsic bioremediation, or
natural attenuation, of chlorinated solvents in ground water
can occur at sites where indigenous microbial populations
are present  that  can degrade  these chemicals. Certain
microorganisms are  capable of  detoxifying  chlorinated
methanes, ethanes, and aromatica by reductive dehalogena-
tion or by oxidation. These processes can result in complete
biodegradation to innocuous end products. The objective of
the natural  attenuation research effort is to quantitatively
determine where, at what rate,  and under what conditions
natural attenuation occurs. Data from both field and labora-
tory  studies will be used to develop a  predictive natural
attenuation  model that will relate the measured degradation
rates to the expected time course and outcome of  intrinsic
bioremediation. The Consortium initiated  the Phase  I
Intrinsic  Bioremediation Study at  Dover AFB, where
chloroethenes are present in shallow ground water. Key to
selection of Dover AFB as the test site was the presence of
an active microbial population, which was evidenced by the
detection of degradation products at the site.

Accelerated  Anaerobic Biodegradation.  The  rate  of
in situ anaerobic dechlorination is typically limited by the
availability  of food and nutrients for microbial growth. The
purpose of the accelerated anaerobic degradation study is to
discover what these nutritional  limitations are and how to
effectively  deliver nutritional additions  to the aquifer in
order to facilitate the use of this technology at other sites.
Other study objectives include determining which  electron
donors and acceptors best support anaerobic bioremediation;
optimizing  the chlorocarbon  destruction rate;  determining
what factors control the degradation kinetics; and gathering
cost and performance data. The Bioremediation Consortium
has begun a Phase I field study to test the accelerated anaer-
obic process at Dover AFB.

What Are the  Consortium

Members' Roles?
Every Consortium member plays a specific role  in the collab-
orative efforts for the three bioremediation processes. Each
organization brings particular knowledge and  expertise, as
well  as laboratory research, field studies,  and resources
necessary to conduct the projects and evaluate the effective-
ness of the technologies.
The companies are sharing proprietary information, patented
technologies, and their collective understanding and experi-
ence in bioremediation mechanisms and  kinetics, hydroge-
ology, and nutrient delivery systems to support the develop-
ment and testing of the three bioremediation processes.
EPA's National Risk Management Research Laboratory
(NRMRL) in Cincinnati, Ohio, is applying its knowledge and
experience in developing bioventing processes to support the
laboratory and  field  testing efforts  for the  cornetabolic
bioventing study. The Air Force  brings its expertise in biore-
mediation and bioventing, as well as support for site charac-
terization and field work at Dover AFB. DOE is applying its

-------
substantial bioremediation expertise and laboratory experi-
ence, as well as tools for microbial characterization that will
be useful in these studies.

What Activities Have Been

Completed?
Cometabolic Bioventing. Using Dover AFB soil, intensive
testing with microcosms revealed that cosubstrates propane
and toluene stimulated TCE biodegradation at relatively fast
rates.  Soil column tests, established to simulate  in situ air
injection,  confirmed  the  microcosm  tests. Propane  was
chosen to be used as the cosubstrate for the field pilot test.
The  column tests  also  showed that  propane  stimulated
           Intrinsic Bioremediation and
       Accelerated Anaerobic Biodegradation
                        Ground Water F ow
cometabolic biodegradation of a co-contaminant at Dover
AFB, trichloroethane (TCA). A pilot-scale field system was
designed and installed at the Bldg. 719 site at Dover AFB, a
jet engine maintenance facility  with associated TCE- and
TCA-contaminated soil. The  pilot system is scheduled to
begin operation in October 1997. A mathematical model is
being developed to simulate cometabolic bioventing. It will
be tested against the monitoring data generated in the field
test.

Accelerated Anaerobic Biodegradation.  As part of pilot
start-up procedures, a tracer test was performed to monitor
hydrologic performance within the test cell. Data from this
test were used to  calibrate the flow and  transport model
developed during the pilot design. Based on tracer test and
operating data from the first year of operation, the pilot is
performing as designed in terms of nutrient delivery and
water movement. PCE and TCE have been degraded to levels
below detection limits in approximately half of the pilot cell.
Significant  degradation of these compounds has occurred
over the rest of the pilot area. Cis-DCE levels have increased
with no apparent degradation of this daughter product to date.
As a result of this development, the Consortium elected to
augment a portion of the pilot with microorganisms that have
the ability to further degrade DCE and vinyl chloride. The
Consortium is hopeful  that the augmenting organisms will
complete the degradation process after sufficient residence
time has  elapsed. Operation and evaluation of the pilot is
scheduled to continue until February 1998.
Intrinsic Bioremediation. A modular computer model for
simulating natural attenuation  in  ground  water has been
developed. The Consortium intends to use data collected as
part of the intrinsic pilot in the application of the model to the
Dover AFB site. The model will be in the public domain and
can be used on personal computers. A detailed analysis of
ground-water data from site-monitoring wells was used to
calculate the apparent flux of chlorinated compounds across
the plume. Results are being compared with similar calcula-
tions made using ground-water data collected as part of an
elaborate  "transect" study involving over  100  discrete
ground-water samples.  The samples were collected along
three "transects" of the plume using direct-push  sampling
techniques. In addition to sample  collection,  individual
measurements of hydraulic conductivity were made at each
location. The Consortium will evaluate these two methods of
flux calculation within  the next program year. The intrinsic
bioremediation study is scheduled to run through 1998 at
Dover AFB.

What Activities Are Planned?
Research efforts on the three Phase I projects  will continue
until  1998.  Hill  AFB has been chosen  for Phase  II
Cometabolic Bioventing work. Currently, lab work using site
soil is underway. The  Consortium continues  to search for
sites for Phase II Intrinsic Bioremediation and Accelerated
Anaerobic Biodegradation work.

What Are  the Funding

Sources?
EPA provides the necessary funds and staff to support and
facilitate  Bioremediation  Consortium  meetings.  Staffing,
funding, and equipment needed to develop and test these
three bioremediation processes are being provided by the
Bioremediation Consortium members. Both EPA and the Air
Force  work   through a Cooperative  Research  and
Development Agreement, which allows government agencies
to work with industry on collaborative research efforts. DOE
has contributed significant funding for the intrinsic bioreme-
diation and accelerated anaerobic biodegradation  Phase I
projects. The Phase I cometabolic bioventing field study has
been primarily funded by the EPA, the Air Force, and Zeneca.

-------
Who Are the Consortium Members?
 .L/ffl.
        Beak International
        Ciba-Gcigy Corporation
        Dow Chemical Company
DuPont
General Electric
IC1 Americas
Novartis
Zcneca, Inc.
n
U.S. Air Force
U.S. Department of Energy
U.S. Environmental
  Protection Agency
              The Bioremediation Consortium
                      Steering Committee
Beak International
Dave Major
519-763-2325
dmajor@beak.com
Novartis
John Licala
910-632-2372
john.Iicala@ep.novartis.com
Dow Chemical
Gary M. Klecka
517-636-3227
usdowq8x@ibmmail.com
DuPont
David E, Ellis
Steering Committee Chairperson
302-H92-744S
ellisde@csoc.dnct.dupont.com
General Electric
Joseph Salvo
518-387-6123
salvo@crd,ge.com
                                    ICI Americas
                                    Martin Bell
                                    011-44-1928-517-875
                                    martin.bell@ukrnh72.c+p.ici.tmailuk.spr
                                    int.com
                                    Zeneca
                                    Malcolm Watts
                                    302-886-3085
                                    U.S. Air Force
                                    Catherine Vogel
                                    904-283-6208
                                    cathy_vogel@ccmail.aleq. tyndall.af.mil
                                    U.S. Department of Energy
                                    Skip Chamberlain
                                    301-903-7248
                                    grover.chamberlain@em.doe.gov
                                    U.S. EPA/National Risk Management
                                    Research Laboratory
                                    Gregory D. Sayles
                                    513-569-7607
                                    sayles.gregory@epamail.epa.gov
    RTDF
Remediation Technologies
  Development Forum
                                            Would You  Like

                                         More Information?

                                        For more information on the Bioremediation
                                               Consortium, please contact:

                                                  David E. Ellis, Ph.D.
                                               DuPont Specialty Chemicals
                                                  Barley Mill Plaza 27
                                            P.O. Box 80027 - Routes 141 & 48
                                                 Wilmington, DE 19880
                                                   Tel: 302-892-7445
                                           E-Mail: ellisde@csoc.dnet.dupont.com

                                                Gregory D. Sayles, Ph.D.
                                           U.S. Environmental Protection Agency
                                           National Risk Management Research
                                                     Laboratory
                                            26 West Martin Luther King Drive
                                                 Cincinnati, OH 45268
                                                   Tel: 513-569-7607
                                          E-Mail: sayles.gregory@epamail.epa.gov

                                           For information on the RTDF or other
                                         Action Teams, please visit the RTDF World
                                         Wide Web site at www.rtdf.org or contact:

                                                   Robert Olexsey
                                           U.S. Environmental Protection Agency
                                            26 West Martin Luther King Drive
                                                 Cincinnati, OH 45268
                                                   Tel: 513-569-7861
                                           E-mail: olexsey.bob @ epamail.epa.gov

                                              Walter W. Kovalick, Jr., Ph.D.
                                           U.S. Environmental Protection Agency
                                               401M Street, SW (5102G)
                                                 Washington, DC 20460
                                                   Tel: 703-603-9910
                                         E-mail: kovalick.walter@epamail.epa.gov

                                         To request other RTDF fact sheets, please
                                                     write/fax to:

                                                     EPA/NCEPI
                                          11305 Reed Hartman Highway, Suite 219
                                                 Cincinnati, OH 45241
                                                   Fax: 513-489-8695
                                                                          Copied on Recycled Paper

-------