'v • /
      JJnited States
      Environmental Protectipn
      ^Agency
Office-df Research and
Development
Washington, DC 20460
January 1992
      Ground-Water
      •—    ,       -?~ ~ »  -
      Research

      Research Description
      Third Edition
                               ^
                                     u -

-------
                                                                                          •*'  1         "I            t   J        HI
                                                                                          j"      ,             * '   -  *
                                                                           ii           jjii    f    |iiK     1  f1   h hii f   rrf         l   j 11
                                                                                                                                                                                                   i         i
                                                                                                                                                    , I           *J,      t )
 "I,  Ml,"'"% 1   .,
1         «            ,.
                                                                                                       •\        -          i
                                                                                                                        «    i IB,
                                                                                                                                                              1'
                                                                                                                                                                    T        r-        1
                                 •If*    |  I  ^   ,'/

                                             ,   .,  I   M
                                                                                                                                               "I I  "
                                                                                                                                                                   1 T  > 1     1^1
                                                             4     i
                                                                                                                                                          V
                              I      f
                                                 •"  i|   l     l||       pi      |jji    l  •   III III l III  pi   IJi||iliifJ	   illliif'jlil l(ljf  l   i|l	(i     H   j'M  , I     '    *
                                                        1	                   ii     '      T"          *         "i  f   '   i   *'   f «u,      i       n       j    A
                                                                                               u
                                                                                                                                     •«       '  j  I1     i  11   f I   I' ,-J    I   i  [
                                                                                                                                        ^   l                ^   ^    i  «
                                                                                                                                    ,              .                   -^      ',
                                                                                                                            1   «'
                                           I       I   I  111
                                                                                                                "w      I yi
                                                                                                                                 ni»y   null   j^    IM i
                                                                                                                                   "l   Tl     ""(
                                                                                                           H      4*    "•     Jl
                                                                                                                        j^


                                                                                                                     ll       't   ,1
                                                                                                                             ii    hi'
                                                                             ^         r      ^            L      ^     ""*       /   '1     J*
i   in ill   in  in 111 In in  i   ii in i n ill (in ill lip  11111| i ill in 11 ml pi ill i  i  in i i|i i(| llHIiiiiiiii mill i n (in  i|i  Hill 11 Hi i fin i •-,--   i   •   ill ' I'llHi   in i,'   .  i  I ^ i  ii
                                                                i t        |      u,     11         i  |
                                                          i   !(   i     r  i1     i,  ,   in i    ,    j 11
                                                                                     *        >
                                                   141^               g(           1   1 W

                                                        m             r   i   j          'rt'      i
                                                                                                  '*«    jl   j
                                                                                                                '         '  II     '
                                                                                                                                                                                    -"'   '    _   *   ii"   ,T
                                                                                                                                                                                     T
                                                              I           <     l

-------
     Ground-Water Research

        Research Description
                Third Edition
                Prepared for the

        Office of Research and Development
Office of Technology Transfer and Regulatory Support
       U.S. Environmental Protection Agency
            Washington, D.C.  20460   .

            Peter W. Preuss, Director
       Amy Mills, Work Assignment Manager
                                                  EPA/600/R-92/004
                                                     January 1992
       Prepared under Contract #68-DO-0171
                     by

   Environmental Management Support'"0
           1010 Wayne Ave., Suite 200
          Silver Spring, Maryland 20910
                (301) 589-5318
                                         Printed on Recycled Paper

-------

-------
                                      PREFACE
    This document describes the ground-water research program  conducted by EPA's Office of
Research and Development (ORD).  It updates the earlier Research Program Description, Ground-
Water Research (EPA/600/9-89/088, October 1989).  The  research program is carried out by the
Offices of Environmental Processes and Effects Research (OEPER), Modeling, Monitoring Systems,
and Quality Assurance (OMMSQA), Environmental Engineering  and Technology Demonstration
(OEETD), and Exploratory Research (OER).  Of ORD's 12 laboratories and four research groups,
four laboratories have lead responsibilities and base budgets in ground water:  OEPER's Robert s!
Kerr Environmental Research Laboratory in Ada, Oklahoma (RSKERL-Ada); OEPER's Environ-
mental Research  Laboratory  in  Athens, Georgia  (ERL-Athens);  OMMSQA's Environmental
Monitoring  Systems Laboratory in Las Vegas, Nevada (EMSL-LV); and OEETD''s Risk Reduction
Engineering Laboratory in Cincinnati, Ohio (RREL-Cin). ORD's Center for Environmental Research
Information (CERI) conducts educational seminars and prints  and  disseminates publications in
support of the ground-water research program.  The overall program is coordinated by the ORD
Matrix Manager for Ground-Water Research. The current matrix manager is Peter Preuss, Director
of ORD's Office of Technology Transfer and Regulatory  Support,  Further information may be
obtained by contacting the ORD laboratories, offices, and  technical experts listed in the Ground-
Water Research Technical Assistance Directory (EPA/600/9-91/006, March 1991), which is available
from CERI  at FTS-684-7391 or 513-569-7391.

    Further information may  be obtained by contacting the directors of the  following ORD
facilities:
        Director
        Calvin Lawrence
        Gareth J. Pearson
        Rosemarie Russo
        E. Timothy Oppelt
        Clinton W. Hall
Facility
CERI
EMSL-LV
ERL-Athens
RREL-Cin
RSKERL-Ada
FTS Phone
684-7391
545-2203^
250-3134
684-7418
743-2224

-------

-------
                              GROUND-WATER RESEARCH DESCRIPTION
                                        CONTENTS

Introduction	 .                 1
    Background	* \    i
    EPA Program Office Responsibilities	   2
        RCRA Hazardous Waste	          2
        Superfund	                       3
        Drinking Water	_	   4
        Pesticides	  '  ]   4

Research Program Overview	                5
    Ground-Water Research Areas	            5
        Site Characterization and Monitoring  	   5
        Transport and Transformation  	     5
        In Situ Aquifer Remediation	.                  5
        Underground Source Control	       ~\ '' ' [   5
        Technology Transfer and Technical Assistance	   6
    Related Research Areas	.       !!!      6
        Health Effects	       6
        On-Site Treatment Technology	'.'.'.'.'.   6
        Surface Source Control	;	   g

Current Research Program  .	     g
    Site Characterization and Monitoring Research	   7
        Well and Sampling Methods	.!.,!..!   7
        Geophysical Methods	                       7
        Wellhead Protection	            g
        Underground Storage Tank Methods	'....'..'.'.'.'.'.'.'.   8
        Advanced Field Technologies   	'     g
        Demonstrations	                  g
        Models	p	,        9
    Transport and Transformation Research	'.	        9
        Hydrologic Transport Processes	t  10
        Estimation of Transformation and Transport Constants	  10
        Abiotic Processes	  H
        Biotic Processes	                .         12
        Hazardous Waste Exposure Assessment	;	i.....  13
        Wellhead Protection Methods	  14
        Pesticides Exposure Assessment Methods	       14
        Midwest Agrichemical Surface/Subsurface Transport and Effects Research ..............   16
        National  Center for Ground-Water Research	'.'.'.'.'.'.'.  16
        Hazardous Substance Research Center Program	   17
        Office of Exploratory Research Grants Program	" .17
    In Situ Aquifer Remediation Research	] '  ig
        Delivery and Recovery Techniques	   	!.....!.   18
        Optimizing  Pump-and-Treat Technologies	  18
        Vapor Phase Extraction Techniques	'.'.'.".'.'.'.'.'.'.'.'.'.'.'.'."  19
        Bioremediation	  	'.'.'.'.'.'.	    	 20
        Underground Storage Tank Remediation Research	 21
    Underground Injection Control Research	.....'.'.'.'.	 22
        Hazardous Waste Injection Methods for Class I Wells	...........]..    22

-------
ii
GROUND-WATER RESEARCH DESCRIPTION
        Class V Well Injection Methods	  22
    Technology Transfer and Technical Assistance	..  .	  23
        Geophysical Technical Support		  23
        Transport and Transformation Technical Support			  23
        Aquifer Remediation Technical Support	  24
        Training and Model Evaluation	  25
        Superfund Technical Assistance Response Team	  25
        Forum Issue Papers 	• • •	  26
    Relationship of ORD Research to Other Ground-Water Research in EPA	  26
    Coordination Among Federal Agencies	•	  27
    External Research Reviews	  28
    Internal Research Reviews		• •	  29
    Research Results	:....:-.	•	  29
    Future Program	,	  30

Appendix A. ORD Ground-Water Research Budget	  33

Appendix B. Summary of Outputs from Ground-Water Research Projects .	 .  35

Appendix C. Recent ORD Ground-Water Publications	  49

-------
                                GROUND-WATER RESEARCH DESCRIPTION
 INTRODUCTION

     Ground-water quality has  a major impact on
 human health and the  environment  The  impor-
 tance of ground water  for consumption and agri-
 cultural and industrial uses, as  well as the  role of
 ground water as part of the hydrologic cycle and
 consequent interaction  with the environment, has
 become increasingly apparent in a number of EPA
 programs.  Research is needed to support EPA
 programs that  require  increasingly sophisticated
 knowledge and greater  technical assistance to ^
 develop and implement human health and environ-
 mental protection  programs.   While significant
 strides have been made in understanding various
 aspects of ground-water science  and technology,
 the scope of ground-water research needs has been
 broadened  by greater  concern for ground-water
 quality,   new legislation  and  regulations,  better
 problem  identification,  and a tendency for inves-
 tigations  to uncover ever greater variability in the
 chemistry, physics, and  biology of the subsurface.

 Background

     While EPA has no  single  authority  under
 which it  is charged to protect ground water, most
 statutes that govern the Agency's mission address
the need to protect ground  water. Some  of the
most significant include:   the  Resource Conser-
vation and Recovery Act (RCRA);  Comprehensive
Environmental Response;  Compensation, and Lia-
bility Act (CERCLA or Superfund); Safe Drinking
 Water Act (SDWA); Clean Water Act (CWA); and
Federal  Insecticide, Fungicide, and  Rodenticide
 Act  (FIFRA).   This broad spectrum  of statutory
 authority within the Agency has contributed to a
variety of  ground-water  issues, priorities, regu-
lations, and research needs.

    EPA  ground-water   research reflects  the
diverse  priorities  among  seven  program  office
clients:  Office  of Ground Water  and Drinking
Water (OGWDW); Office of Solid Waste (OSW);
 Office  of  Emergency  and  Remedial  Response
 (OERR);  Office of Waste Programs Enforcement
 (OWPE); Office of Underground  Storage  Tanks
 (OUST);  Office of Pesticide Programs (OPP); and
 Office  of  Radiation Programs.    The  research
program  also supports  EPA's ten  Regions  and a
number  of cross-media offices and  task  forces.
 Because  States and EPA policy  delegate many
ground-water  protection responsibilities  to  the
states  and regional  variations  in hydrogeology,
EPA  is increasing its emphasis on providing in-
formation and direct technical assistance  to  state
and local agencies that must apply new knowledge
and technologies to local problems.

    The overall research and technology  transfer
program is guided by three EPA research commit-
tees and four Office of Research and Development
(ORD) offices.  The research committees—Water,
Hazardous  Waste/Superfund:, and Pesticides—are
joint  ORD/program  office/Regional committees
responsible  for  reviewing  research  programs,
ranking research  needs, and recommending  allo-
cations  of research  funds  to  ORD's Assistant
Administrator.  ORD's  research offices—Model-
ing, Monitoring  Systems, and  Quality Assurance
(OMMSQA), Environmental Processes and Effects
Research  (OEPER),  Environmental  Engineering
and Technology  Demonstration  (OEETD),  and
Exploratory Research (OER)—are responsible for
coordinating ground-water research programs and
overseeing  the  operations of  the research  lab-
oratories within their program areas.

    Responding  in part to a recommendation by
the Science Advisory Board, in 1986 ORD's Assis-
tant Administrator created a matrix manager for
ground-water research to be responsible for cross-
office,  cross-research-committee   coordination
among competing priorities.  Program office and
ORD technical specialists and managers participate
in periodic  reviews, led by the matrix manager, of
ground-water research priorities and outputs.   The
reviews serve to refine research priorities based on
the evolving  knowledge of ground-water  science
and needs of the  program offices. They form the
basis for defining and communicating ORD's di-
rection in ground-water research.

    In  1989, EPA's Administrator established a
Ground-Water Task Force to  review the Agency's
ground-water protection  program and to develop
concrete principles and objectives to ensure effec-
tive and consistent decision-making in all Agency
decisions affecting ground water.  The outcome of
this effort is policy and implementation principles
that are intended to  set forth  an aggressive  ap-
proach to protecting the Nation's ground-water re-
sources  and  direct the  course  of the  Agengy's
ground-water program.

-------
2
GROUND-WATER RESEARCH DESCRIPTION
    EPA's responsibilities in ground water include
providing technical  and  financial  assistance to
guide state  and local governments  in the devel-
opment of their ground-water protection and man-
agement programs,  and  developing  policies to
ensure integration and consistency of approach for
federal  programs focused  on ground-water  pro-
tection.  To support EPA responsibilities, ORD
offices and laboratories conduct their own research
as  well as fund  research  at  other  institutions,
including universities and colleges, state and other
federal  laboratories, associations, and consulting
and engineering firms.  ORD research provides
tools for decision-making at all government levels
to  improve the  protection of  ground-water re-
sources from  man-made contamination.  In ad-
dition to  designing a research program to satisfy
multiple needs, ORD coordinates with other federal
agencies concerned with ground-water problems.

     The   objectives  of  ORD's   ground-water
research programs are the development of methods,
data, and  guidance for  detecting and monitoring
various  point  and  nonpoint sources of contam-
ination, predicting  subsurface transport and fate
processes  to  better assess human  and environ-
mental exposure to ground-water  contamination,
 controlling contamination from numerous possible
 sources, and restoring contaminated aquifers to a
 point where human health and the environment are
 no longer at risk.   Research into  predicting the
 distribution, movement,  and fate  of  man-made
 contaminants  in ground water is basic to ground-
 water protection and sets the pace  for progress in
 controlling contamination sources  and remedial
 action.   To  ensure that  the  latest science and
 technology advances are applied to  ground-water
 problems  by  government and private sector de-
 cision makers, ORD has implemented technology
 transfer and technical assistance programs.

 EPA Program Office Responsibilities

      This section summarizes the responsibilities of
 EPA Program Offices,  Regional Offices, and  the
 states and the resulting information needs to which
 ORD's ground-water research program responds.
 Although research results have broad applicability,
 in practice, research activities are supported  by,
 and performed in  support  of,  individual EPA
 programs.
                         RCRA Hazardous Waste

                         The  management  of  regulatory  programs
                     under RCRA and the Hazardous and Solid Waste
                     Amendments of 1984 (HSWA) is the responsibility
                     of OSW, OUST,  and OWPE.   RCRA and  its
                     amendments allow states to take over responsibility
                     for program implementation and enforcement and
                     provides for oversight by EPA's Regions.  Because
                     the hazardous waste program is what most people
                     think of when  RCRA is mentioned,  the  terms
                     "hazardous  waste" and "RCRA" are used inter-
                     changeably  to refer  to  research  in support of
                     hazardous waste (RCRA Subtitle C), municipal
                     waste (RCRA subtitle D), and underground storage
                     tanks (RCRA Subtitle I) regulatory programs.

                          Subtitle' C of RCRA established a program to
                     manage hazardous wastes from "cradle to grave,"
                     including the generation, transportation, treatment,
                     storage, and disposal of hazardous wastes,  Facil-
                     ities regulated by OSW under RCRA include con-
                     tainers, tanks, surface impoundments, waste piles,
                     land   treatment  units,   landfills,  incinerators,
                     underground injection wells, and chemical,  phys-
                     ical,  and biological  treatment processes.  RCRA
                      also  authorizes  corrective  action  cleanups  at
                     facilities from which hazardous wastes have been
                      released into the subsurface.  Regional  and state
                      permitters and  enforcement personnel f£need me-
                      thods   to   establish  ground-water   monitoring
                      programs to detect  pollutants  migrating  from
                      facilities and to monitor compliance with permit
                      conditions.   Information on  the  transport  and
                      transformation of contaminants in ground water is
                      needed to  assess potential health  and environ-
                      mental  impacts of various regulatory options  and
                      to clean up ground  water contaminated by impro-
                      per hazardous waste disposal.

                           Subtitle D  of RCRA established a program to
                      assist  states  who voluntarily develop and imple-
                      ment municipal waste management plans.  It also
                      required OSW  to issue minimum technical stan-
                      dards  to  which all municipal  waste  disposal
                      facilities  must  comply before  accepting  solid
                      wastes.  These  minimum standards are outside the
                      voluntary state program and  cover ground-water
                      monitoring,  siting   of  facilities,  and  corrective
                       actions. EPA  municipal waste activities declined
                       in the early 1980s, but now  are on the increase
                       because of  many  reported instances of  ground-

-------
                                GROUND-WATER RESEARCH DESCRIPTION
water contamination from municipal waste dumps.
The 1984 amendments to RCRA required EPA to
revise, if necessary, the criteria for municipal waste
facilities,  incinerator  ash  monofills,  and  land
application units.  To support environmentally safe
municipal  waste   management,  the  states need
information  on  suitable  monitoring  strategies,
methods to predict the transport and transformation
of contaminants in ground  water, and remediation
methods  for  cleaning up contaminated soils and
ground water. The revised  Subtitle D Solid Waste
Disposal Facility  Criteria  were  published in the
Federal  Register  in  October,  1991,  and  will
become effective in October, 1993.

     Subtitle I of RCRA established  a program to
regulate  over  1.5 million underground  storage
tanks (USTs), hundreds  of thousands of which are
suspected  to  be  leaking  petroleum  products.
OUST has developed  performance standards for
new  tanks  and  regulations  for leak  detection,
prevention,  and corrective action  at all  under-
ground tank sites.  Because of the number  of
tanks, OUST has designed a program in which the
states have responsibility,  after approval  of their
programs by EPA, for controlling leakage from
underground  tanks.   The  1986  amendments  to
CERCLA provided for  a  Leaking  Underground
Storage Tank Trust Fund to finance  corrective
actions necessitated by leaking underground tanks.
OUST and the states need information on methods
to monitor the subsurface around USTs and clean
up contaminated aquifers and soils.

     Superfund

     OERR  is  responsible  for mitigating  threats
from abandoned,  high-priority,  hazardous waste
sites  under CERCLA and  its amendments.  The
Hazardous Substance Response Trust Fund (Super-
fund)  was  established  to  finance  EPA-lead
remedial  actions   at  CERCLA  sites,  short-term
removal   actions   to   lessen  imminent  threats,
emergency  responses  to  accidental spills,  and
research.    EPA   policies  and  procedures  for
implementing Superfund responses are contained in
the  National Contingency Plan  (NCP), which
delineates   criteria  for   when—and  to  what
extent—a removal or remedial response should be
undertaken.

     Preliminary assessments must be conducted at
sites reported as possible sources of contamination
or illegal dumping (now over 31,00.0 sites).  If the
preliminary  assessment shows  that  there  is  an
immediate need for action, a removal action may
be  initiated to stabilize or  eliminate the release.
EPA on-scene coordinators (OSCs) in the Regions
direct   Superfund-flnanced   removal  activities.
-When  a preliminary assessment shows that the site
may threaten human health or the environment, the
site is  inspected to collect sufficient information to
rank its hazard potential, including risks to ground
water.    If  a long-term  remedial  response  is
required, a lead organization is determined,  which
may be OERR, the state, or the responsible  party;
the latter under supervision of OWPE.  The Site
remedial response is  managed  by a Regional re-
medial project manager (1RPM) when OERR has
the lead.

    Sites are subjected to a remedial investigation
to gather data necessary to determine the type and
extent of soil, ground water, and other contam-
ination at each  site   and  a feasibility  study  to
analyze cleanup needs and alternative approaches.
After completing these studies, a remedial design
is developed, including detailed engineering  plans,
drawings, and specifications.    "'-'   ' '"-:   -r ~-

    OSCs,  RPMs, and  their  state  counterparts
need   monitoring  procedures   and   analytical
protocols to quickly  and effectively assess the
degree of hazard  posed at waste sites.  They need
methods to  determine the transport  and  trans-
formation of contaminants in the  subsurface and
innovative  remedial   technologies  to  clean up
contaminated  sites.    Although microbial  degra-
dation of contaminants in  the subsurface has great
potential to cost-effectively clean up some Super-
fund sites, a great deal of research is required to
determine which  contaminants are amenable to in
situ microbial  remediation  and how to evaluate
controlling  processes, design  criteria,  costs, by-
products, and site-specific effects.

    Enforcement powers have been granted to
EPA to gain the  compliance of recalcitrant RCRA
facility  and underground storage tank  owners,
oversee  Superfund site cleanups, and  recover the
costs  of site  cleanups financed  by Superfund.
These  enforcement  powers  are  employed  by
OWPE and its counterparts in the Regions and
states.  Enforcement  personnel need ground-water

-------
                                GROUND-WATER RESEARCH DESCRIPTION
information similar  to that needed by  RCRA,
Superfund, and  UST regulatory, permitting, and
response personnel in order to defend the scientific
and technical merit underlying decisions in these
programs.

    Drinking Water

    Under  the  authority  of SDWA,  OGWDW
publishes maximum  contaminant level  goals and
promulgates  national   primary  drinking  water
regulations for all contaminants that may have  an
adverse effect on human health and are known or
anticipated to occur in public water systems. The
list of  potential contaminants must be  updated
every three years.  OGWDW  will propose regu-
lations in 1993 requiring the disinfection of ground
water not under the influence of  surface water,
which is  used as source water for public supply
systems.  These  regulations  are planned to  be
promulgated in 1995. Variances may be granted if
it can be shown that the source water is likely to
be  free  from pathogen contamination  and other
distribution system requirements. The Clean Water
Act also contains provisions affecting ground-water
quality, including provisions for area-wide  waste
treatment management plans  and  protection  of
ground water quality  from  nonpoint sources  of
pollution.

    Approximately  40% of the chemical  waste
generated  in the  United  States is disposed  by
injection  into the subsurface.  Both SDWA and
HSWA contain provisions to protect ground water
quality  from  the  injection of  waste  into  the
subsurface by means of deep wells.  Regulations
for underground injection control have been based
on  ensuring that the use of injection wells for the
disposal of waste will not  endanger human  health
or the environment.

     OGWDW is also responsible for the wellhead
protection program mandated by  SDWA.  SDWA
requires each state  to  develop an EPA-approved
wellhead protection program  to  protect  public
water wells from  contaminants.    Most  states
already have an EPA-approved program in place or
are actively developing such  a  program.  EPA-
approval requires consideration  of a number of
technical  elements,  which  include:  the hydro-
geologic setting, delineation of protection areas,
and assessment  of potential contaminant sources.
    To carry out their ground-water protection
responsibilities, OGWDW and the States must de-
velop methods to assess the risk to human health
from various categories of potential contamination
sources, determine the likelihood that a chemical
will persist  in the subsurface, and  develop well-
head protection strategies.  To support these activ-
ities, research is needed to  improve methods for
detecting  and monitoring ground  water contam-
ination, predict the transport and transformation of
pollutants in ground water,  and use in  situ tech-
nologies to remediate ground-water contamination.

    Pesticides

    FIFRA established a program that bans  all
pesticides unless they  are  registered with OPP.
OPP has set forth guidelines specifying the kinds
of information required to support the registration
of  a pesticide, including  data on the  anticipated
extent of use, pattern of use, and level and degree
of potential exposure to humans and the environ-
ment.  When used in  accordance with commonly
recognized  practice,  pesticides  must  not  cause
unreasonable adverse effects to the environment.
Although the extent of exposure to human popu-
lations through drinking water is not certain, EPA
recently  completed  a  National  Pesticide  Survey
(NPS) to help evaluate the  degree  of nitrate and
pesticide  contamination in  drinking water  wells.
The focus of the  survey was on drinking water
quality in wells  and results  showed an abundance
of nitrate contamination in many community water
system wells and  rural drinking  water  wells.
Results also showed that  many  community water
system wells  and  rural  drinking  water  wells
contain at least one pesticide or pesticide degradate
that exceed national Health Advisory Levels and
Maximum Contaminant Levels.   The Agency's
Pesticides and Ground-Water Strategy  stresses a
localized  approach  for protecting  ground  water
from pesticide contamination by building Regional
and state capabilities and encouraging the states to
develop pesticide management plans.

     Techniques are needed to predict the fate of
pesticides in the subsurface  on a site-specific basis
and measure environmental exposures of pesticides
that threaten human health, impair important en-
vironmental functions, and endanger  untargeted
biota.

-------
                                GROUND-WATER RESEARCH DESCRIPTION
RESEARCH PROGRAM OVERVIEW

    Three laboratories have lead responsibilities
for ground-water research: the Robert S. Kerr En-
vironmental Research Laboratory  in Ada, Okla-
homa  (RSKERL-Ada),  Environmental  Research
Laboratory in Athens, Georgia (ERL-Athens), and
Environmental Monitoring Systems Laboratory in
Las Vegas, Nevada (EMSL-LV).  The Risk Reduc-
tion Engineering Laboratory in  Cincinnati,  Ohio
(RREL-Cin), also conducts ground-water research,
but  concentrates primarily  on  water  and  soil
treatment technologies.

    ORD's ground-water research program can be
organized  into five areas: site characterization and
monitoring; transport and transformation;  in situ
aquifer  remediation;  underground source control;
and technology transfer and technical assistance.

Ground-Water Research Areas

    Site Characterization and Monitoring

    The placement  and  spacing  of monitoring
wells,  procedures  for   sample  collection  and
preservation, and quality assurance and  quality
control (QA/QC) are fundamental requirements for
the collection of credible data to support ground-
water protection decisions.    ORD's monitoring
research program is developing, evaluating, and
adapting geochemical and geophysical monitoring
techniques  to  meet  the  needs of EPA and the
regulated  community,  evaluating  site  character-
ization methods to improve  monitoring well net-
work design,  and refining  procedures  for data
reduction and interpretation.   The lead laboratory
for monitoring research is EMSL-LV.

    Transport and Transformation

    Predicting   contaminant  behavior  in  the
subsurface  is one of the most difficult tasks for
ground-water  protection  programs.   Transport
research considers the physical movement of water
and  contaminants in the  subsurface.    Trans-
formation   research  considers  biotic and  abiotic
processes  in the saturated and unsaturated zones
that change the form, species  (for example, of
metals and ionizable organics), or composition of
ground  water  contaminants.    The  knowledge
gained  about   transport,   transformation,   and
speciation phenomena is Incorporated  into pre-
dictive models to enable the prediction estimation
of  contaminant  behavior in  the subsurface  and
potential exposures to humans and  the environ-
ment.  The lead laboratories involved in fate and
transport research are RSKERL-Ada  and ERL-
Athens.

     In Situ Aquifer Remediation

     Cleaning up a polluted aquifer is a technically
difficult process, if it can be done at all.  Effective
cleanup methods are  needed to remove contam-
inants from many different hydrogeologic settings.
ORD's aquifer remediation research is developing
methods to recover contaminants from aquifers  for
on-site treatment, making in situ remediation tech-
niques more effective  and less  expensive,  and
identifying factors that contribute to the success or
failure of existing cleanup techniques.   Advances
in aquifer remediation methods are highly depen-
dent on  advances in the understanding of sub-
surface processes affecting the behavior of contam-
inants in the subsurface.   Aquifer remediation  re-
search projects are often conducted in conjunction
with  transport   and   transformation  research.
RSKERL-Ada is the lead laboratory in subsurface
remedial processes.  RREL-Cin operates a remedial
technology program which concentrates on above-
ground and in situ soil clean-up technologies

     Underground Source Control

     A major source  of ground-water  contam-
ination is the  improper  injection of hazardous
wastes into the subsurface. Leaking well casings,
abandoned and improperly sealed wells, injection
of agricultural, industrial, and urban drainage waste
waters into shallow aquifers, and upward migration
of  hazardous  wastes  from deep injection into
drinking water supplies all need to be evaluated to
determine safe  underground  injection  practices.
ORD maintains a small research program in under-
ground source control which develops protocols  for
injection  well practices,  evaluates well casing test
methods, and studies the interaction of injected
material with subsurface materials. The lead lab-
oratory for underground source  control research is
RSKERL-Ada.

-------
                                GROUND-WATER RESEARCH DESCRIPTION
    Technology Transfer and Technical Assistance

    Field personnel in EPA Regions,  states, and
local  governments must  deal with an extremely
broad and complex range of technical information.
They  benefit from  close  support  from scientists
and engineers in ORD laboratories.  Ground-water
issues are a major category of technical requests
from  client offices.  To  be effective,  research
results must be  disseminated  to  targeted  oper-
ational personnel, program managers, and decision
makers in a timely manner and effective format.
ORD's lead in technology transfer is the Center for
Environmental Research Information (CERI).   In
addition,   all  laboratories   routinely  conduct
technology transfer and offer technical assistance.

Related Research Areas

    ORD also conducts  research in the areas  of
health  effects,   above-ground  treatment  tech-
nologies, and  surface source  control.   Although
closely related to ground-water research, they are
not considered components of the ground-water
research program in this research description.

    Health Effects

    The  major  route  of  human  exposure  to
ground-water  contaminants is through  drinking
water.    Illnesses   attributed  to  ground-water
contamination account for a significant amount of
all reported waterbome diseases. Research on the
health effects of particular pollutants  is used to
establish credible safe drinking water  standards,
demonstrate to the public that the standards are
based  on  sound data,  and design health-based
cleanups of hazardous substances  in the environ-
ment.  ORD's Office of Health and Environmental
Assessment (OHEA)  conducts a research program
to develop methods for predicting human exposure
risks  from hazardous  materials,  including  the
estimation  of exposure  to contaminants  found in
drinking-water supplies.    Since  adverse health
effects are the same regardless of whether exposure
is through ground water or surface water, research
on health  effects is not considered part of the
ground-water research program.

     On-Site Treatment Technology

     EPA has a major research, development, and
demonstration program investigating technologies
for treating hazardous substances  on site (above
ground)  to reduce  or eliminate  their  volume,
toxicity,  or  mobility.   This program  provides
performance   and   cost   data   on    available
technologies for treating  volatile and non-volatile
organics, inorganics, metals, and microbes.  Infor-
mation on treatment technologies is being  devel-
oped for the drinking water, Superfund, hazardous
waste, and pesticides programs.  On-site treatment
technologies  are often used  for treating ground-
water contaminants after they are  pumped  to the
surface. However, on-site  treatment technologies
are not included in this  description  because they
are not specific to ground water.  Technologies for
bringing contaminants to the surface for on-site
treatment  are  being  developed  for  corrective
action/remediation of contaminated  soil.   These
technologies are discussed under the section on  in
situ aquifer remediation because they may also be
used for that purpose.  RREL-Cin has expertise  in
this area for research on in situ on-site treatment  of
contaminated soils.

    Surface Source Control

    The surface source control research program
develops technologies to  prevent soil and ground-
water contamination in and around Superfund sites,
RCRA  facilities,  and underground storage tanks.
Engineering  research  activities  include:  1)  im-
proving land-disposal containment systems, such as
slurry  cut-off walls,  landfill < covers; and 2) de-
veloping  methods for treating hazardous  wastes
and soils by leachate repirculation, soil washing, in
situ  flushing,   and   chemical    stabilization/
solidification.  ORD also  develops  guidance and
procedures for siting, designing, maintaining, and
closing hazardous  and municipal facilities,  under-
ground  storage tanks, and other waste management
facilities.   The objective  of this  research is  to
reduce the health risks from  soil contamination or
contaminant  migration to  ground  water.  RREL-
Cin is active in this research.
 CURRENT RESEARCH PROGRAM

     The FY91 ground-water research program had
 a budget of approximately $25  million and 105
 FTEs.  The FY92 ground-water research budget is
 proposed to be  increased  to  approximately $30

-------
                                GROUND-WATER RESEARCH DESCRIPTION
million and 106 FTEs (see Appendix A),   ORD
deliverables,  outputs, and other accomplishments
expected to be  completed in FY91, FY92, and
beyond are listed in Appendix B.

Site  Characterization  and  Monitoring
Research

     The goal of ground-water monitoring research
is to develop techniques for detecting and quan-
tifying  changes  in hydrogeology  and subsurface
water quality.  Techniques that are being  devel-
oped to monitor the subsurface more effectively
include well and  sampling methods, geophysical
methods,  wellhead  protection  methods,  under-
ground  storage tank methods,  and advanced field
technologies. Demonstrations of these methods are
being conducted to test their  effectiveness, and
modeling techniques are  being developed to opti-
mize use of monitoring data.

     Well and Sampling Methods

     Conventional  monitoring   of  ground  water
involves drilling monitoring wells, using various
devices for collecting samples (bailing, pumping,
in situ  samplers),  and sending the samples to a
laboratory for analysis. A great deal of research in
the past few years has provided  monitoring well
constructionimethods and sampling techniques that
produce samples more representative of the source.
EMSL-LV  is continuing its  effort  to  improve
ground-water  monitoring methods  through  the
development of  guidance on sampling frequency,
well casing materials, and monitoring well network
design.   Investigations  are being conducted  to
provide an understanding of the temporal varia-
bility of ground-water quality in an arid environ-
ment  and   validate  elements  of  ground-water
sampling protocols.

     Among the sources  of ground-water contam-
ination  are the  leachates  from  Superfund  and
RCRA  sites.   In recognizing that the target ana-
lytes identified by EPA  monitoring methods  ac-
count for a  small percentage  of the potentially
hazardous organic contaminants present in these
leachates, EPA instructs its  contract laboratories to
identify other chemicals  that are present at high
concentrations.   Similar identifications are needed
in characterizing ground water.  EMSL-LV is coor-
dinating research at Las Vegas and ERL-Athens to
expand the number of compounds that can be iden-
tified reliably and  cost  effectively  in hazardous
waste  disposal site  leachates and ground water.
knowledge of chemicals present in these ground-
water sources will provide a basis for significantly
improved assessments.

     Geophysical Methods

     Advanced   geophysical   methods   for   the
detection,  mapping,  and monitoring of contam-
inants  in ground water  and  the  vadose (unsat-
urated) zone of show great promise  in saving the
Regions  and states time and expense in character-
izing the subsurface. EMSL-LV is  developing  a
number of new geophysical (remote sensing) meth-
ods  to  delineate  subsurface  characteristics  and
contaminant locations.

     Geophysical  research  for RCRA hazardous
waste  sites concentrates on adapting  borehole
technologies to lower the cost of hazardous waste
facility monitoring.   A number of new instruments
and  techniques have recently been developed and
are being evaluated for hazardous waste site inves-
tigations.   These  new  technologies include  the
development of radar tomography techniques and  a
new transient  electromagnetic  sounding (TEM)
instrument.  Field evaluations of these new  tech-
nologies  will be conducted and results compared to
standard  surface, borehole, and surface-to-borehole
geophysical techniques along  with coring of the
wells.

     To  support  the implementation of SDWA
provisions   concerning  underground   injection
control (UIC) and wellhead protection, EMSL-LV
is testing cost effective monitoring technologies for
protecting ground-water sources of drinking water.
EMSL-LV  is examining the resolution and detec-
tion   limits   of  surface-to-borehole   electrical
resistivity methods for mapping and monitoring of
fluid movement from underground  injection wells.
If successful,  this  geophysical  method would
provide the only method for monitoring  the deep
injected contaminants.  Other geophysical methods
are  also being  investigated   for detecting  near-
surface contamination caused by  upward move-
ment of contaminants through abandoned wells and
fracture zones.

     Seismic techniques have proven effective for

-------
8
GROUND-WATER RESEARCH DESCRIPTION
characterizing the subsurface at many locations. In
particular, seismic shear-wave  methods  in  com-
bination with compression-wave (p) surveys have
been very successful.   An  improved shear-wave
source for shallow seismic studies has been devel-
oped  by EMSL-LV for characterizing the  sub-
surface in urban areas.  EMSL-LV is also exam-
ining the effects of the interaction between organic
chemicals and  clay minerals on the  response of
resistivity surveys.   In  addition, new  electro-
magnetic systems are being developed  for  haz-
ardous waste site investigations.

    New modifications in ground penetrating radar
(GPR)  equipment, field  procedures, and  field
investigations  are  being evaluated by EMSL-LV.
This technology makes  use  of the fact that radar
pulses directed into the ground are reflected  back
toward the surface at points where a contrast exists
in the electrical properties of subsurface materials.
GPR surveys can  provide high-resolution data for
delineating  subsurface  properties  at hazardous
waste sites.

     Wellhead Protection

     In contrast to RCRA  and Superfund moni-
toring needs, where contaminants are monitored to
detect migration  from a site, wellhead protection
monitoring designs must provide warning of con-
taminants migrating toward a water supply well or
well field.  In addition, wellhead protection  areas
can be very large, requiring many wells  or moni-
toring points.   EMSL-LV is developing guidance
on cost-effective monitoring strategies for wellhead
protection areas to warn of contaminants nearing
drinking water wells.

     Underground Storage Tank Methods

     To  support  the  implementation of under-
ground  storage  tank regulations, EMSL-LV is
emphasizing  the  development of protocols for
installing external leak  detection  systems, site
characterization  procedures  for determining the
boundaries of active leaks, and methods to monitor
cleanups and  remediation as well as technology
transfer.

     Installers   of  underground  storage  tank
monitoring systems need guidance on the design
 and   performance  characteristics •  of  external
                     monitoring systems.   To provide' this guidance,
                     EMSL-LV is .evaluating external vapor monitoring
                     methods for petroleum hydrocarbons.   Standard
                     operating procedures for external vapor monitoring
                     devices are being  developed  to  help  installers
                     select and install effective systems.  EMSL-LV is
                     also conducting a study to  monitor a  permeable
                     peat barrier designed to remove petroleum contam-
                     inants  from the ground water.  This  study  will
                     include the monitoring of dissolved hydrocarbons
                     in the ground-water up-gradient, on the sides, and
                     the  down-gradient  of permeable  barriers  that
                     contain peat, carbon,  and time-released fertilizer.
                     Methods are also being developed to monitor ben-
                     zene, toluene, ethylbenzene, and xylene  (BTEX),
                     major  carcinogenic  components in  petroleum, by
                     analyzing soil, soil gas, and  ground water.  BTEX
                     is the most water-soluble fraction of  petroleum,
                     and is  therefore the most threatening to ground-
                     water supplies.

                          Natural  biodegradation  processes  can  be
                     expected  to reduce  contaminant  migration  and
                     eventually result in complete contaminant degra-
                     dation after removal of the  contamination source.
                     Field methods  are being developed to monitor
                     vapor  and ground-water movement around USTs
                     and devise  practical biodegradation solutions for
                     state regulators and   consultants.    Passing  this
                     valuable information  to consumers through pub-
                     lishing UST issue papers.

                          Advanced Field Technologies

                          New  technologies  capable   of  rapid  data
                     generation in the field are  greatly reducing the
                     amount of time required to  assess  contaminants at
                     Superfund sites. EMSL-LV has established an ad-
                     vanced field monitoring methods research program
                     to identify,  evaluate,  and  accelerate  the devel-
                     opment of  promising  on-site monitoring technol-
                     ogies.. These technologies enable rapid screening
                     for contaminants at a site but are not  intended to
                     be substitutes for traditional sampling and analysis.
                     Technologies currently  being emphasized in the
                     program  are  fiber optic-based sensing,  immuno-
                      assay detection methods, and  portable X-ray fluor-
                      escence (XRF) systems.

                          X-ray  fluorescence spectrometry methods  are
                      being developed for  detecting metal contaminants
                      and fiber optic technologies for in situ monitoring

-------
                                GROUND-WATER RESEARCH DESCRIPTION
of organic contaminants in ground  water.  The
application of these technologies will provide site
investigators  and  operators of  hazardous  waste
facilities with a field technology to rapidly screen
for hazardous constituents migrating from a site.
EMSL-LV has developed  a portable,  ultraviolet
field spectrofluorometer (Luminoscope) for detec-
ting aromatic hydrocarbons in ground water, soil,
and waste material.

    The temporal and spatial behavior of volatile
organic compounds (VOCs) and characterization of
VOC-contaminated sites  are  important consid-
erations when designing a monitoring system as
well as evaluating and interpreting data.  EMSL-
LV is conducting  studies to improve site character-
izations   and  contamination   assessments   at
Superfund sites.   These studies will provide prac-
tical, field tested  methods for site characterization
that will allow consistent collection, analysis,  and
interpretation of site data.

    Demonstrations

    Establishment of  the  Superfund  Innovative
Technology  Evaluation (SITE) program  was re-
quired by the Superfund amendments 6f 1986 to
speed  up commercialization and  application  of
promising new technologies.   Under the  SITE
program,  the  performance  of monitoring  tech-
nologies are  demonstrated at Superfund  sites by
their  developers,   while EPA  provides quality
assurance oversight and  analysis of the demon-
stration results.    The  SITE  program  currently
consists of ten demonstration projects for soils and
ground-water research.

    SITE demonstrations emphasize simple, rapid,
and inexpensive field-deployable monitoring instru-
ments  that utilize fiber-optic, immunoassay, XRF
and other innovative technologies.  Procedures for
proper operation  of these technologies are  being
developed as  systems are demonstrated.  Field
demonstrations concentrate on carefully  selected
technologies  because  the  expense of field work
limits  the number of technology demonstrations.
EMSL-LV is currently adapting a prototype of the
Ultrasonic Ranging and Data System (USRADS)
to the  XRF.  This adaptation will greatly enhance
field screening methods and further optimize data
presentation  during  the  initial  Superfund  site
investigation  and  throughout  the  remediation
process.   This will  save time and expense  arid
enable Superfund site managers to make better and
more timely decisions in the field.

     Legislation is pending in Congress that would
exempt municipal  waste  gombustion (MWC)  ash
from RCRA and require EPA to develop special
regulations for MWC ash disposal under Subtitle
D.  To support development  of these  regulations,
EMSL-LV is conducting monitoring  studies  for
MWC  ash.  The objectives of the research are to
characterize the behavior of MWC ash in standard-
ized laboratory test  procedures and evaluate  the
sensitivity of leaching results to controllable testing
factors.  The results will  provide  the  technical
basis for guidance on cost-effective ground-water
monitoring strategies appropriate for RCRA Sub-
title D MWC ash monofills.

     Models

    In  support  of  EPA's monitoring  research,
models are being developed to optimize prediction
of  the  migration  of contaminants,  characterize
subsurface  heterogeneities,  and optimize ground-
water monitoring network design.   EMSL-LV is
developing new geostatistical  methods  to improve
monitoring  network  designs for  contaminated
hazardous waste sites.  In addition, mathematical
models for evaluating data requirements  are being
developed.   The main focus of this research is on
development of models to guide the practitioner in
analyzing and testing data,  developing reasonable
models  to  describe  spatial   variability,  testing
various  modeling  assumptions,  and  statistically
testing boundary value solutions.
Transport and Transformation Research

    Lack of understanding the movement of con-
taminants in the subsurface and  their transfor-
mation by natural environmental processes severely
restricts the Agency's  ability  to protect ground-
water quality and to design  effective systems for
cleaning up contaminated ground water. The im-
pacts of regulatory options can be evaluated based
on  predictions of contaminated concentrations at
some  point of .exposure.    Such predictions are
dependent  on   a  qualitative  and  quantitative
understanding,of subsurface  processes.   Research
into  the   transport  and    transformation   of

-------
10
GROUND-WATER RESEARCH DESCRIPTION
contaminants in the  subsurface is fundamental to
advances in monitoring,  aquifer remediation, and
underground source control research.

    Research to gain a better understanding  of
contaminant transport and transformation involves
hydraulic processes,  abiotic processes, biotic pro-
cesses,  hazardous   waste   exposure  assessment
methods,   wellhead   protection  methods,  and
pesticides  exposure  assessment methods.   EPA
established the National Center for Ground-Water
Research  (NCGWR) in September,  1979, as  a
consortium of Rice  University, the University of
Oklahoma, and Oklahoma State University,  for
developing  and conducting  a .long-range  ex-
ploratory research program to help anticipate and
solve  emerging ground-water  problems.    The
Hazardous Substance Research  Center ,(HSRC)
program was  also established to support research
for hazardous substance management.

     Hydrologlc Transport Processes

     RSKERL-Ada's highest priority  research is
the investigation of complex subsurface properties
and processes that enhance or retard the transport
of organic contaminants.  Although the flow of
water through uncontaminated, homogeneous aqui-
fers is  reasonably well understood,  the processes
affecting the transport of contaminants by  ground
water,  particularly in heterogeneous  aquifers, is
poorly  understood.  This  RSKERL-Ada research
concentrates  on developing  an understanding of
processes that either retard or facilitate the move-
ment of contaminants in the subsurface and using
this information to improve the capability  of pre-
dicting contaminant  concentrations.

     "Facilitated transport" encompasses processes
that increase contaminant mobility, which  can re-
sult in ground-water contaminants moving faster
than expected. Because contaminants leaking from
hazardous waste facilities  are commonly complex
mixtures of organic compounds, RSKERL-Ada is
investigating  the effects of  solvents within these
mixtures  on  the  mobilization of other  contam-
inants. Data from experiments are used to develop
and  evaluate  mathematical descriptions  of  the
phenomenon.

     Laboratory tests have shown that significant
 amounts of immiscible contaminants, such as gas-
                     oline, can be trapped in soil pore spaces, making
                     them difficult  to  remove from  the subsurface.
                     RSKERL-Ada is studying how these contaminant
                     residuals are released from pore spaces, the effect
                     of trapped  contaminants on transport of dissolved
                     contaminants, and  the use  of solvents to enhance
                     contaminant release from pore spaces.

                          The movement of contaminants through soil
                     macropores and fractured  bedrock  is one of the
                     most difficult  conditions  to predict.   The  pre-
                     dominant flow, which can be very rapid, is through
                     macropore  cracks  and fracture  zones in the  bed-
                     rock.  Movement also can occur through the  rock
                     matrix, depending  on its porosity. Laboratory and
                     field studies are providing data on the processes of
                     porosity, diffusion, sorption, and ion-exchange that
                     control transport in fractured systems.  These data
                     are being used to develop and test models that pre-
                     dict the transport of contaminants in  fractured
                     bedrock.

                          Estimation of Transformation  and Transport
                          Constants

                          To apply  the results  of mechanistic process
                     studies to  the  prediction  of transport and trans-
                     formation,  it  is  necessary to  know  appropriate
                     physical  properties  and   equilibrium  and  rate
                     constants  for  the  many potentially ^hazardous
                     organic chemicals that are found in ground water.
                     Measurement of such properties  and constants is
                     prohibitively  expensive  for large numbers  of
                     chemicals  and the  accuracy of measurements is
                     usually  poor,   for  hydrophobic  chemicals  in
                     particular.   ERL-Athens  is  developing  computa-
                     tional methods that will permit the rapid, accurate,
                     and  inexpensive  estimation  of  such  constants.
                     "Spare Performs Automated Reasoning in Chem-
                     istry"  (SPARC)   has  the  capability of  crossing
                     chemical boundaries to cover all organic chemicals
                      and uses algorithms based on  fundamental chem-
                      ical  structure  theory.    The  system  quantifies
                      reactivity  by combining principles  of quantitative
                      structure-activity  relationships, linear free energy
                      theory,  and perturbed molecular  orbital  theory.
                      CRAMS (Correlations of Reactivity and Molecular
                      Spectra) correlates the vast amount of information
                      contained  in  molecular  spectroscopic properties
                      with  chemical reactivity  and applies  the  corre-
                      lations to  the estimation of properties of chemicals
                      found in  ground  water.    The two systems  are

-------
                                 GROUND-WATER RESEARCH DESCRIPTION
                                             11
complementary.

     Abiotic Processes

     RSKERL--Ada transport and transformation re-
search emphasizes investigations of organic con-
taminant transport.  RSKERL-Ada's research into
transport phenomena for  the  drinking water pro-
gram concentrates on sorption processes affecting
organic contaminants.  Past research with organic
contaminants has indicated a number of important
sorption processes that need study. While sorption
can  retard  the spread of  contaminants in ground
water, it can also make contaminant removal very
difficult and time  consuming.  RSKERL-Ada also
conducts research on the spatial variability of sub-
surface properties, transport of metals  attached to
colloids, viability  of hazardous  waste land treat-
ment and fate of  residual hazardous wastes after
closure of RCRA facilities.

     A  series  of RSKERL-Ada  research projects
are  investigating  the processes that  control the
sorption of miscible and immiscible organic con-
taminants to subsurface materials.  The compara-
tive  sorption of organic cations  to clay minerals,
soils containing low levels of organic material, and
soilis containing high levels of organic material is
being studied.  In addition, the effects of dissolved
natural organic carbons  on the partitioning of im-
miscible organic contaminants between water, dis-
solved organic carbons, and soils  is being inves-
tigatedi  Algorithms that  can  describe these sub-
surface processes quantitatively  are  being  de-
veloped, validated through laboratory and  field
experiments, and included  in predictive models.

     Vapor-phase transport in the unsaturated zone
is an important transport route  for organic contami-
nants, such as  gasoline  and many solvents.   This
transport is influenced by soil  moisture content*
distribution of organic  vapors between the  con-
densed  and vapor phases,  and amount of organic
vapor present in soil pore spaces. RSKERL-Ada is
conducting  laboratory research  to  quantify the
influence of soil moisture content on the sorption
and  transport of  a  number  of selected organic
vapors.  The  collected  data will be used to test
existing models for soil vapor  transport.

     RSKERL-Ada is studying whether the sorp-
tion  of pollutants to  organic materials in soils and
 aquifers is influenced not only by the equilibrium
 capacity  of sorption  but  also  the  strength, or
 energy, of sorption.  The strength of the sorption
 process is one factor potentially influencing  bio-
 availability  and degradation of pollutants in the
 subsurface.  Methods for defining this factor are
 being studied.

     RSKERL-Ada is also investigating an abiotic
 process that can significantly affect organic con^
 taminants in certain subsurface environments.  The
 role of subsurface soils containing iron and sulfur
 minerals in the transformation of halogenated or-
 ganic compounds  is being studied.   The  surface
 area, elemental composition;  sorption, and other
 parameters expected to  affect reactivity are being
 studied to determine the  properties  that  control
 these reactions.  Reaction rates are being measured
 to  enable the  development  of a  mathematical
 model describing this process.

     ERL-Athens  conducts  research  on  sorption
 processes to complement  that of RSKERL-Ada.
 Investigations of the sorption of ionizable organic
 pollutants, particularly carboxylic acids, have led;
 to the  development of process models that accu-
 rately predict the partitioning of such  compounds
 between water and solids in sediments  and aquifer
 materials. Studies are now underway on the parti-
 tioning of organic cations, particularly aromatic
 amines at low pHs, which bind to solids by mech-
 anisms  different from those for organic  anions.
 Research  indicates  that  these  compounds bind to.
 humic  materials by'strong covalent binding that is
 irreversible.                    ,       ,

     ERL-Athens also conducts research on abiotic
 fate of metals in aquatic systems, including aqui-
 fers.   For  example, partition coefficients were
 measured for 13 metals  and metalloids of particu-
 lar interest to the Office of Solid Waste because of
 potential leaching and transport into ground water.
 Profiles of joH versus concentration in the aqueous
 phase  were generated  that  showed a  strong
 tendency for metal cations to be solubilized as the
pH decreases, and gave credibility to the use of the
 model  MINTEQ to predict speciation  (and trans-
 port) of metals  at various pHs.

     An understanding of the transformation pro-
 cess is essential to predicting  the fate  of organics
 in aquifer systems.  ERL-Athens research has fo-

-------
12
GROUND-WATER RESEARCH DESCRIPTION
cused on two important processes—hydrolysis and
redox reactions.  Hydrolysis is a commonly occur-
ring process that may completely transform a pol-
lutant to an innocuous product in a  few minutes.
However, recent studies have shown that even rela-
tively stable halogenated hydrocarbons, such  as
TCE and other commonly used solvents, can react
with  water with  half-lives  of a few  years, a
timeframe of a concern to ground water.

    Redox  reactions  are interesting processes in
ground  water  because of the facility with which
reduction or  oxidation  occurs in  anaerobic  or
aerobic  systems,  respectively,  and  because  the
products are harder to predict and may be toxic.
Halogenated aromatic  and aliphatic  hydrocarbons
have also been shown  at ERL-Athens to reduce to
lower order halogenated  species with half-lives of
minutes to years.  A knowledge of the mechanisms
of  these processes may  lead to  technology for
chemical remediation of contaminated ground wa-
ter.  The chemical reduction process, for example,
is being adapted to treatment of nitroaromatics in
wastes from munitions manufacturers.

     Blotlc Processes

     Other   high-priority  transport   and  trans-
formation research includes the transformation of
organic compounds by indigenous microorganisms.
RSKERL-Ada conducts  smaller research projects
to  study the  transport  of viruses  and  bacteria
through the subsurface.

     Subsurface   biological   processes  have  a
significant impact on  transformations  of ground-
water contaminants.  RSKERL-Ada  is conducting
laboratory  microcosm experiments to  develop an
information base  on  the aerobic degradation of
classes  of organic contaminants and pesticides by
microorganisms  native  to  different   subsurface
environments.  The  research  is evaluating impor-
tant physical  and chemical subsurface soil char-
acteristics,  microbial  activity in different soils,
enzymes involved in the  degradation processes,
and predominant chemical reactions. Correlations
between microbial type, sediment type, and  bio-
degradation potential are being sought to determine
processes that limit or stimulate biodegradation.

     Since  the  discovery of  abundant microbial
 activity in  anaerobic  subsurface  environments,
                     studies  of anaerobic biodegradation of  organic
                     contaminants are being emphasized to find  ways to
                     improve biodegradation  potential in anaerobic en-
                     vironments.   Models for predicting the anaerobic
                     biodegradation of contaminants in the subsurface
                     are  being  developed   and  their  performance
                     evaluated using field and laboratory data.

                          Although the natural microbial degradation of
                     organic contaminants in the subsurface is being
                     used to clean up contaminated sites, the movement
                     of  microorganisms  in  the  subsurface  and  their
                     colonization in areas of  contamination are not well
                     understood.  Remediation techniques presume that
                     contaminated aquifers   already  harbor  organisms
                     that are capable of degrading  the  contaminant.
                     Site-specific  information is  needed  that  can  be
                     used to evaluate the prospects for colonization of a
                     contaminated aquifer or the unsaturated zone  by
                     microorganisms.  RSKERL-Ada is developing an
                     understanding of the properties of microorganisms
                     and subsurface materials that determine the trans-
                     portability  of bacterial  strains  through geologic
                     material and  whether  a particular  site  will  be
                     colonized by microorganisms capable of degrading
                     wastes.

                          In addition to protecting drinking water  from
                     organic, pesticide, metal, and other hazardous con-
                     taminants, public water  supplies need to be protec-
                     ted  from disease-causing viral contaminants.   Im-
                     proved models are needed to refine the transport of
                     viruses through  both  saturated  and  unsaturated
                     zones and to examine  the  influence of pumping
                     wells  on  their movement.   An  improved model
                     will have more accurate capability of delineating
                     zones around drinking  water wells,  within which
                     potential sources of viral contamination should not
                     be  placed if contamination by viruses is to be
                     avoided.    A  model  has  been  developed  by
                     RSKERL-Ada for personal computers.

                          ERL-Athens conducts  research on the biotic
                     processes to complement  that  of RSKERL-Ada.
                     Fundamental research focuses primarily on investi-
                      gations of the microbial physiology of anaerobic
                      microorganisms, microbial  ecology of reductive
                      dehalogenation processes, identification of specific
                      electron donors and key environmental factors that
                      influence the  rate  and extent  of dehalogenation
                      under  anaerobic conditions, and development of
                      model(s)  describing  the   anaerobic  degradation

-------
                                 GROUND-WATER RESEARCH DESCRIPTION
                                                                                                  13
 process. Applied research is aimed at developing,
 testing, and evaluating anaerobic assays, and deter-
 mining key pathways for the degradation of single
 and mixtures of organic chemicals often observed
 in ground-water environments and hazardous waste
 sites.  This work leads directly to the development
 of tested protocols, which will be used in the de-
 velopment of appropriate remediation and migra-
 tion strategies  to ensure effective and consistent
 decisions-making  that  will affect  the Nation's
 ground water.

     Hazardous  Waste  Exposure   Assessment
     Methods

     The data  and mathematical descriptions  de-
 veloped through  research for the RCRA program
 are being used by RSKERL-Ada and ERL-Athens
 to  develop and  test  models for predicting  the
 concentrations  of hazardous wastes released from
 RCRA  facilities.    A  goal  of RSKERL-Ada's
 ground-water modeling research is to provide field-
 evaluated models to predict the  concentrations of
 contaminants in the subsurface  at some point of
 discharge or use.  RSKERL-Ada is also developing
 and testing in the laboratory a numerical model to
 predict  two-dimensional,   multi-phase,   multi-
 component flow.  RSKERL-Ada develops and  ap-
 plies model testing and evaluation methodologies
 to improve access to quality  assured models.

    Two large  physical models that  simulate
 ground-water flow and subsurface conditions have
 been constructed  at RSKERL-Ada.   The  model
 aquifers are instrumented to track the  transport and
 fate of introduced contaminants.  The aquifers  are
 artificially  contaminated and  then  monitored  to
 assess  contaminant movement and the results of in
 situ cleanup methods.   Although these physical
 model  tests  are conducted under simplified condi-
 tions, they provide a cost-effective transition from
 bench-scale  verification of  model predictions  to
 expensive, full-scale field testing.

    Most   subsurface  formations   are  hetero-
 geneous, but the impact of variability in subsurface
 properties that control pollutant transport and fate
 is not well understood. RSKERL^Ada is develop-
ing methods for  characterizing the variability of
 subsurface properties on a site-specific  basis and
evaluating  the  impact of  spatial variability  on
transport processes and  chemical  and biological
 reactions at selected sites.  Statistically valid and
 field-tested methods are being developed for use
 by field  personnel for cost-effectively character-
 izing the spatial variability of subsurface properties
 at waste sites.

     ERL-Athens'  transport  and  transformation
 research objective is to develop  and refine  expo-
 sure assessment models for use by OSW in eval-
 uating land disposal and  facility closure options.
 The development of data on  metal and organic
 contaminant reaction rates for use in these models
 is an important aspect of EJRL-Athens research.

     ERL-Athens  is  refining  "MHMTEQA2",  a
 metals fate model being used  by OSW  to deter-
 mine the potential human health and environmental
 impacts of RCRA regulatory options.  The current
 research  supporting MINTEQA2 includes incor-
 porating non-linear sorption algorithms and a built-
 in thermodynamic database for metals sorption into
 the model, evaluating lead pathways, and testing
 MINTEQA2 at sites in Globe,  Arizona and Lead-
 ville, Colorado.  A new  interactive preprocessor
 has been developed to facilitate automatic assem-
 bly of MINTEQA2 input files,  and a new conver-
 gence algorithm has been developed for the model.

     A lanthanide ion probe spectroscopic method
 for efficiently  measuring metal complexation con-
 stants with complex natural humic  materials was
 developed and applied.  The new  method has thus
 far been used to generate new thermodynamic data
 for use in the MINTEQA2 code  and has  enabled
 the evaluation of metal/humic interactions  in a
 number of soil and sediment  systems.   Results
 were  specifically applied  in evaluating  leachate
 transport from waste disposal sites.

    ERL-Athens  conducts;  research to  estimate
 reaction rates that control  the transport and trans-
 formation of organics in trie unsaturated zone and
ground water.  This data is needed to  improve
 input data for the EPA Composite Model for Land-
 fills  (EPACML),  a ground-water  model  for esti-
mating organic contaminant attenuation and trans-
port through  the  unsaturated  zone and  ground
 water. ERL-Athens has developed  an approach for
estimating microbial  and  abiotic  rate-constants
based  on mathematical modeling  of  molecular
structure.   Detailed laboratory  studies  are being
conducted to describe hydrolysis and redox trans-

-------
14
GROUND-WATER RESEARCH DESCRIPTION
formation reactions as a function of key environ-
mental parameters (pH  and redox potential) and
molecular structure.  Molecular structure is deter-
mined by spectroscopic analysis  (which is much
less expensive than laboratory rate  constant mea-
surements) and  correlated to the transformation
rates of similarly structured compounds determined
in the laboratory.

    A range  of organic  contaminants  has been
subjected to laboratory assays  to  examine  how
their  chemical structure  and key  environmental
parameters   influence   microbial    degradation.
Models  that  describe  the  rate and  extent  of
microbial degradation of benchmark chemicals are
being refined. Degradation rates for additional or-
ganic contaminants are then estimated in a model
by relating  their structure  to  the  benchmark
chemical degradation  rates.    Laboratory exper-
iments are conducted to  determine  the effects of
important environmental  variables  and  to  verify
selected estimated biodegradation rate constants.

     Wellhead Protection Methods

      ORD and OGWDW have prepared  a five-year
research  plan and established a State  and Local
Review  Group (SLRG) to help ensure that well-
head protection research meets the needs of antici-
pated users. RSKERL-Ada is conducting research
 on wellhead protection area (WHPA)  delineation
 methods, point-source assimilative capacity, multi-
 ple source assessment, and technology transfer and
 technical assistance.

      Wellhead Protection Area delineation research
 includes: joint work with the state of  Utah, U.S.
 Geological Survey (USGS), and  Region VII  to
 develop a method for protecting springs; evaluation
 of  a WHPA  delineation model  developed  by
 OGWDW; and evaluation of regional ground-water
 flow models.   In addition, projects to evaluate
 WHPA delineation uncertainty, delineate WHPAs
 in  fractured rock systems, consider  viruses  in
 WHPA delineation methods, and  improve simple
 delineation methods are  being  completed.  In the
 longer-term, a draft research plan has been pre-
 pared for  developing methods to  account for the
 capacity of the subsurface to assimilate point sour-
 ces  of contaminants  and existing  information on
  assimilative capacity is being compiled.
                         Existing ground-water quality  data  is being
                     collected to create a database for the development
                     of models relating multiple  sources of  contami-
                     nants  within  WHPAs  to  shallow ground-water
                     quality.  The study includes statistical evaluations
                     to determine the significance of hydrogeologic fac-
                     tors, such as depth to ground water, surface geo-
                     logy, ground-water flow direction, and  recharge.
                     Statistical relationships between human  activities
                     and ground-water quality and subsurface character-
                     istics will be used to determine areas where there
                     is high potential for ground-water  contamination.
                     A geographical information system will be devel-
                     oped to allow easy management and interpretation
                     of Regional information.

                          A risk-management  strategy  for  wellhead
                     protection is being developed for formulating land-
                     use controls within a protection area. The project
                     will be  conducted in three  phases: development
                      and verification of the theoretical  framework for
                     determining risk  distribution within a  wellfield;
                      development  and verification of particle tracking
                      algorithm to  calculate the risk distribution;  and
                      application of the proposed  strategy  within  an
                      existing WHPA to demonstrate its usefulness.   •

                          ERL-Athens  is  developing a  model for the
                      drinking water program, called Computer Assisted
                      Simulations for Chemical and Demographic Evalu-
                      ations (CASCADE) to estimate subsurface assim-
                      ilative capacity in agricultural areas.  Climate and
                      soils  databases that have been developed speci-
                      fically to support model application and parameter
                      estimation will be fully integrated into CASCADE,
                      complete with graphical display features and ease
                      of manipulation.   A ground  water  database  is
                      necessary to support CASCADE and will be devel-
                      oped during the course of this research project.  A
                      site will be chosen where data availability is con-
                      sistent with the model application and typical of
                      the  situation faced  by  expected users  to field
                      demonstrate CASCADE for typical users.

                            Pesticides Exposure Assessment Methods

                            ERL-Athens  transport  and  transformation
                       research for the pesticides program has two major
                       components—the development of modeling pack-
                       ages to predict the fate and transport of pesticides
                       in the  subsurface, and major field projects to test
                       the models and collect data on subsurface proces-

-------
                                 GROUND-WATER RESEARCH DESCRIPTION
                                             15
 ses that control pesticide fate.  Limited laboratory
 research is also conducted to fill gaps in parame-
 ters necessary for pesticide exposure modeling.

     A final report on the results of the Dougherty
 Plains project, which evaluated ERL-Athens Pesti-
 cide Root Zone Model (PRZM) and provided in-
 formation on pesticide leaching potential, has been
 released.  ERL-Athens has also completed the third
 growing  season's  data  collection  effort   at  a
 cooperative field site near  Plains,  Georgia and
 developed an interim report on the performance of
 the PRZM and  RUSTIC Pesticide transport mod-
 els.   This research  effort is  being  conducted  in
 cooperation with the  U.S. Department of Agricul-
 ture  (USDA),  USGS,  and  the   University  of
 Georgia.  Data  produced .have also  been used  to
 test  and refine  a new transport code called the
 Aggregate model that accounts for intra-particle
 diffusion processes.   ERL-Athens is also working
 to improve the soils and meteorological databases
 in a Database and Parameter Estimator (DBAPE)
 modeling support package.

    A new input data collector called PIC (PRZM
 Input Collator) has been developed for  use  with
 PRZM.  The PIC system draws on databases from
 DBAPE  and greatly  facilitates user application of
 PRZM. Mapping capabilities are included.

    ERL-Athens  is  developing  a   multimedia
 model for determining pesticide exposures to birds,
 animals,  soil insects,  and  terrestrial ecosystems.
The  Terrestrial  Ecosystem Exposure Assessment
Model (TEEAM) includes PRZM and components
 for spray application, runoff, plant transport, and
 wildlife.   Other components  to be added include
 surface ponding  and volatilization.  A test version
has been developed.   The model is not inherently
limited to pesticide exposure  and may be adapted
for use in estimating exposures from hazardous
wastes.

    Laboratory studies are also being conducted to
relate pesticide molecular structure to the sorption
of pesticides to solids in  anaerobic  aquifers and to
determine the key parameters that  influence  sorp-
tion processes.  This information is being used to
estimate  pesticide reaction rates and equilibrium
constants to improve  pesticide exposure models.

    RSKERL-Ada conducts  research  of a  more
 applied  nature  under the RCRA  program.   By
 statute, the land treatment of hazardous wastes (in-
 cluding residual wastes at closed RCRA facilities)
 must be limited to those wastes that either can be
 treated to performance standards or that have been
 demonstrated to show no migration from the soil
 treatment zone for as long as the waste remains
 hazardous. RSKERL-Ada is conducting land treat-
 ability studies at wood preserving, food processing,
 paint  stripping, and oil  refinery  industry sites.
 This  involves collecting waste and soil samples
 from specific sites and conducting laboratory eval-
 uations of the movement and natural  degradation
 of the wastes.

     EPA's Pollution Prevention Initiative, a plan
 to  provide scientific  tools to states  for imple-
 menting EPA's Pesticides and Ground  Water Stra-
 tegy,  will  provide guidance,  software,  and field
 tests to assist States in delineating and monitoring
 areas vulnerable to  ground-water contamination
 from pesticides.  Under this initiative, ERL-Athens
 is currently conducting work on a pesticide vulner-
 ability assessment  method called Pesticide Assess-
 ment Tool for Rating Investigations of Transport
 (PATRIOT).  This  system  will utilize DBAPE for
 analyzing soils databases and providing State and
 local  agencies a useful screening  mechanism for
 identifying areas of potential pesticides to ground
 water. The product will be a simplified screening
 procedure that makes use of ORD's most current
 data sources and  software  capabilities.   It will
 consist of  a  combined flow and transport model,
 pesticide chemodynamic  and use databases, soils
 databases  management,  soil  water   retention
parameter  generator,  and  ranking  procedures.
 PATRIOT  will be  applicable  at  county  and
 subcounty if digitized surveys are available.

    ERL-Athens will coordinate  with  EMSL-LV
on integration of PATRIOT with Geographic Infor-
mation Systems (GIS) and application of the inte-
 grated system at the Yuma, AZ  and  DelMarVa
 field  sites.    Data  on  pesticide  occurrence  is
 currently being collected on the DelMarVa.  This
 information will be used to  determine  patterns  of
land use and will be related back to  monitoring
 strategies.  PATRIOT will lead to the creation of a
 document describing GIS database design  for pesti-
 cides  management that addresses the  acquisition,
processing, use,  and maintenance of data in GIS
 format.  Region III is coordinating with the United

-------
16
                                GROUND-WATER RESEARCH DESCRIPTION
States Geological Survey (USGS) National Water
Quality Assessment (NAWQA) program and util-
izing National Pesticide Survey data on the Del-
MarVa  peninsula.  This plan involves leveraging
and building upon USGS' field work in progress
on the DelMarVa.

     OPP plans  an  expansion  of  the  existing
Pesticide  Information  Network  (PIN),   which
currently is a collection of three OPP-generated
databases on  a  computer bulletin  board  system
accessible and free  to  the  public.   These three
databases  include:   the   pesticide   monitoring
inventory; the restricted use products field; and the
chemical  index.    As  of FY93,  the  following
databases will be added: the pesticides in ground
water   database;  environmental  fate  one-liner
database; canceled and suspended  use products;
and certification and training bibliography.  This
expansion of the system and revisions of some of
the   software  will  make  more  information
accessible to State users.  A final summary report
will be completed in FY93.

     Midwest   Agrlchemlcal  Surface/Subsurface
     Transport and Effects Research

     The USGS and the USDA are implementing a
joint research program to determine the effects of
 agricultural practices on ground-water and surface
 water quality as part of the President's Initiative on
 Enhancing Water Quality.  A significant compo-
 nent of this  initiative, the  Management  Systems
 Evaluation Areas (MSEA) project, is evaluating the
 effects of alternative farming practices on surface
 and subsurface water quality at five  primary re-
 search, and a number of satellite sites in the mid-
 west  EPA will be joining this inter-agency re-
 search program  in FY92 through  implementation
 of its  Midwest Agrichemical Surface/Subsurface
 Transport and Effects  Research (MASTER)  pro-
 gram.  Five ORD laboratories are  involved in re-
 search for the MASTER program: ERL-Athens,
 ERL-Corvallis,  EMSL-LV,  RSKERL-Ada,  and
 ERL-Duluth.

      Goals for  MASTER include:  determining the
 environmental benefits (ground water, surface wa-
 ter, and related ecosystems) of midwestem agricul-
 tural  management  systems  proposed  for  best
 management practices; identifying  measures for
 preventing ecological  and  hydrologic degradation
and restoring ecosystem functions at the watershed
level; and providing diagnostic and predictive tools
to the states for implementing cross-media water-
quality  management  programs based  on  sound
ecological and hydrological practices.  This will be
done at  site-specific, watershed,  and  regional
scales.  Developing guidelines for minimizing hy-
drologic and ecological impacts of agrichemicals
requires an understanding of the rate and pathways
of chemical movement through the landscape, the
degree  of agrichemical  exposures  to biological
components, and the effects of this exposure.

     One  of the primary research efforts under
MASTER will be the development and testing of
watershed  and  regional  scale  methodologies  for
assessing  the  ecological  impacts   of  various
agricultural production practices.  A cooperative
research/modeling effort  is being implemented in
FY92 at the  Walnut Creek Site, near Ames, Iowa,
tp  develop  the  necessary  processes  data, geo-
graphic information systems,  and  modeling tools
for addressing the watershed and regional scale-up
questions.  Results from this first year pilot assess*
ment will be used  as  a platform  for building
assessment methodologies  applicable  to the 12
state midwestern  corn belt area in future years.
The ultimate products will be aimed at the  de-
velopment of modeling tools and databases  for
evaluating the effectiveness of vaiipus^agricultural
production scenarios in sustaining/improving the
 quality of the agroecosystem.

      National Center for Ground-Water Research

      OER provides base funding for the National
 Center  for  Ground-Water Research  (NCGWR),
 which  is  supplemented  through  agreements with
 RSKERL-Ada, universities, the private sector, and
 other governmental units.  The Center works with
 RSKERL-Ada  and  other  EPA  laboratories   to
 ensure that the exploratory research program  is
 cooperatively planned and linked to the Agency's
 mission.  In the last five years, the Center has
 developed  the  quantitative  data  needed   for
 designing   in   situ  biorestoration   processes.
  Coordination of laboratory studies has helped basic
  science for ground-water problems.           '

      The objective of the NCGWR is to  improve
  understanding  of the subsurface environment and
  its interaction with synthetic organic compounds in

-------
                                 GROUND-WATER RESEARCH DESCRIPTION
                                                                                                   17
 the subsurface, especially in ground water asso-
 ciated with hazardous waste sites. The four major
 areas of responsibility for the Center's research are
 methods  for  ground-water quality investigations;
 transport and fate of pollutants in the subsurface;
 characterization of the subsurface environment; and
 information transfer.   The NCGWR conducts five
 research  projects under cooperative agreements
 with RSKERL-Ada,  including research into land
 treatment, anaerobic microbial degradation, unsat-
 urated  zone  transport modeling, isolation of a
 bacteria for degrading trichloroethylene (TCE), and
 case studies of Superfund site remedial activities.
 OER is supporting projects to study transport and
 transformation processes and to  apply new infor-
 mation to in situ aquifer remediation methods.

     Studies  at Rice  University  have shown that
 exposure to contaminants results in the preferential
 growth of microbes that produce agents that may
 enhance the bioavailability (and degradation) of
 contaminants in aquifers.  Other research  at Rice
 University has included the development  of a
 conceptual understanding of source  effects from
 residual oil residing above the water table  as well
 as  experimentation in. the  laboratory and field to
 investigate this release mechanism. A multi-phase
 unsaturated zone  contaminant  transport (MUCT)
 model was developed to describe the fate of an
 oily waste and the simultaneous vertical flow of
 water and a second immiscible phase fluid through
 porous media.

     A study at the University of Oklahoma used
 microcosms to probe the anaerobic biodegradation
 of  several  aromatic  compounds and  pesticides
 known  to  contaminate aquifers.  An  automated
 data-acquisition device has been invented and is
 now in practical use to measure the production or
 consumption of gaseous end-products  of anaerobic
 metabolism.  Research at Oklahoma State Univer-
 sity has explored the co-metabolism of the ground-
 water pollutant TCE.   To  understand the process
 involved in this research, Oklahoma State Univer-
 sity is attempting to engineer, through recombinant
 DNA techniques, organisms capable of aerobic
 TCE degradation in the absence  of inducing sub-
 strates.     The  bacteria  Alcaligenes  eutrophes
JMP134 has been identified to remove TCE from
 growth  media  when aromatic catabolic pathways
 are activated by the presence of 2,4-D or phenol.
     The  Center's  experimental  and  modeling
 studies  are  being  integrated into a  conceptual
 framework of the bioremediation process.  If this
 effort is successful,  it will result in an engineering
 process  design  manual  for  microbially enhanced
 restoration of contaminated ground water.

     The Center's  information transfer  activities
 include  numerous  presentations  on  subsurface
 chemical transport  and  aquifer  remediation  re-
 search results at local, national, and international
 meetings.  Another highlight of the Center's tech-
 nology transfer  program was the start of training
 activities for the Superfund University  Training
 Institute (SUIT) in cooperation with RSKERL-Ada.

     Hazardous Substance Research Center Program

     The EPA established the Hazardous Substance
 Research Center (HSRC) program in response to
 provisions in the 1986 amendments to CERCLA
 and the  Agency's 1988  Appropriation Act.  The
 fundamental mission of all centers is to provide the
 philosophical framework, organizational  structure,
 and resources  required  to   foster and  support
 integrated,  multidisciplinary,  and  collaborative
 research that advanced the science and technology
 of hazardous substance management.  The HSRCs
 form an integrated national program of basic and
 applied research, technology transfer, and  training.
 The  attention  of  the  five  cooperative multi-
 disciplinary and multi-university centers is on the
 problems  of managing   hazardous   substances.
 Drawing financial support from academia, industry,
 state and federal government, the centers  are able
 to  leverage the  research resources provided by
 EPA.  The centers  also bring together a critical
 mass of researchers to conduct complementary and
 integrated research projects.  Industry, regulatory,
 academic, and other representatives come together,
 through the advisory committee  process, to  help
 shape the center's research agenda.

     Office of Exploratory Research Grants Program

     OER established and manages a program that
 awards grants to qualified investigators who will
 conduct  research in  environmental  chemistry,
physics,  engineering, biology, and health  science.
Topics  supported include  the identification and
 characterization  of   hazardous   substances,
 intermedia transport,  and fate of pollutants, human

-------
18
GROUND-WATER RESEARCH DESCRIPTION
and   ecological  risk   assessment,  incineration,
emission  reduction,  and  wastewater  treatment.
Projects are currently being conducted in response
to a request for applications on innovative restor-
ation technologies for treatment of heavy metals at
Superfund  sites.   This research is an effort to
further  extend the application of  existing tech-
nologies to other types of soil or mixtures of heavy
metals where a  technology has  previously been
successfully demonstrated with single contaminants
in sandy soils. Applications are being accepted in
FY92 for research on pump-and-treat technologies.

In Situ Aquifer Remediation  Research

     In  situ  aquifer  remediation methods show
great potential as  an  alternative remedial action
when a site has  large volumes of  soils with  low
levels of contamination or when  contaminants are
too  deep or inaccessible for surface removal.  In
this  case, the  cost of  excavation for  off-site
disposal or on-site (above ground) treatment are
high in relation to the risk. In situ aquifer reme-
diation  research is often conducted in coordinated
projects with fate and transport research because of
the  necessity  for  determining the location  and
movement of contaminants prior to remediation.
The goal is to evaluate and develop cost-effective
methods  for  in situ  aquifer  cleanup.   Aquifer
remediation research is conducted  for the RCRA
hazardous waste, Superfund,  and  drinking water
programs.

     In situ  aquifer remediation research empha-
sizes the development of  in situ microbial degra-
dation technologies, field  demonstrations of these
technologies, and modeling to help analyze reme-
 dial options.  Another research area is the develop-
ment of contaminant recovery techniques to more
 efficiently  extract  contaminants from the  sub-
 surface so that on-site treatment technologies can
 be applied.

      Delivery and Recovery Techniques

      Efficient recovery of contaminants without
 excavation of soils is essential to on-site treatment
 processes and remedial actions.  Processes for de-
 livering and mixing materials in  subsurface  soils
 are also  essential for effective chemical and bio-
 logical treatment of contaminated soils. RREL-Cin
 develops delivery and recovery technologies and
                     evaluates their effectiveness, cost, and cross-media'
                     impacts.   Technologies  showing potential  for
                     commercial success are  tested through the ORD
                     SITE   program   conducted   by   RREL-Cin.
                     Hydrofracturing and shallow directional drilling are
                     two promising delivery/recovery techniques.

                          Since 1987, EPA has  funded a coordinated
                     program  at  RREL-Cin's Hill Facility  on theo-
                     retical, laboratory,  and  field  investigations  of
                     hydraulic  fracturing  and directional drilling for
                     improving remediation.  The combination of direc-
                     tional drilling and hydraulic fracturing uses water
                     pressure  to  create precisely  located  horizontal
                     cracks  in soils; these cracks  are held open  by
                     injecting a mixture of sand  and an organic binder,
                     These long, sand filled lenses can then  be  used to
                     enhance vapor phase recovery  of organic contam-
                     inants, extraction of ground water, or injection of
                     steam and hot  air for in  situ heating.  The  process
                     is  also being  adapted  for delivery  of materials
                     (nutrients, organisms, solid oxygen sources) to
                     enhance bioremediation  and to control movement
                     of liquids during leachate recirculation treatment of
                     MSW landfills on  EPA's National Priorities List.
                     The  cost  and  performance of this  technology  is
                     being evaluated by  RREL-Cin  at a  soil vapor
                      extraction (SVE) site and a bioremediation site to
                      provide guidance on its  effective use and  bring it
                      to commercial technology stage in FY92-93.

                          RREL-Cin is  also conducting laboratory and
                      pilot-scale research on  optimizing the  design of
                      trenches for recovering leachates  and ground water.
                      This design effort  includes the development of an
                      interactive* computer program that will  simulta-
                      neously optimize cost and performance for combi-
                      nations of recovery trenches and  vertical wells.

                           Optimizing Pump-and-Treat Technologies

                            A common means to recover contaminants
                      from ground  water  is pumping  the water to the
                      surface where a variety of treatment technologies
                      can be applied. A problem commonly encountered
                      with this pump-and-treat technique is that, after an
                      initial rapid decrease in the concentration of ex-
                      tracted contaminants, the last fraction  of  the con-
                      taminants takes a very long time to extract. Pulsed
                      pumping—the intermittent operation of  a pump-
                       and-treat system—is a technique that can lower the
                       expense of pumping and treating large volumes  of

-------
                                GROUND-WATER RESEARCH DESCRIPTION
                                            19
 water  to remove low  concentrations of contami-
 nants.   During periods when pumps are shut off,
 contaminants trapped in pore spaces or sorted-to
 subsurface materials can diffuse into more mobile
 ground-water zones. When the pumps are turned
 back on,  contaminated ground water can be re-
 moved at the maximum concentration.  RSKERL-
 Ada initially conducted research in this area, and
 RREL-Cin is now continuing research to  improve
 understanding of the site-specific  conditions that
 affect  the performance of this extraction process.
 This information will be used to optimize pulsed-
 pumping systems and ensure uniform recovery.

     Pump-and-treat systems in operation at Super-
 fund sites have been failing to reach clean-up level
 goals in projected timeframes for several reasons
 that include inadequate knowledge of site charac-
 teristics, the presence of non-aqueous phase liquids
 (NAPLs), and incomplete understanding  of con-
 taminant related processes.   RSKERL-Ada's Sub-
 surface  Cleanup   and  Mobilization  Processes
 (SCAMP) was initiated to address these knowledge
 gaps for optimizing pump-and-treat technologies.
 SCAMP research is designed to enhance me effec-
 tiveness of pump-and-treat  remediation.  It is  a
 five-year effort with funding at one million per
 year beginning in 1991.   The major long-range
 output from this initiative will be a guidance docu-
 ment for planning  and implementing pump-and-
 treat remediation at contaminated sites.

    The overall objective  of the  research  is to
 acquire process  and characterization information
that will allow development of a decision-making
 framework for predicting the appropriateness and
potential efficacy of pump-and-treat for site reme-
diation. SCAMP research will initially concentrate
on  dense  non-aqueous  phase liquids (DNAPLs),
which  have created major  policy and technical
implications to OSW and Superfund.  DNAPLS
move  slowly  in  the subsurface  but can  move
through fractures  into lower aquifers and diffuse
 into the matrix of rocks.   They can travel in the
opposite direction  of the ground-water flow, and
 are difficult to detect in the  subsurface. Research
projects  will  include  improving  methods  for
characterizing complex  sites and using surfactants
 and solvents to accelerate the removal of DNAPLs.
 In the longer term, RSKERL-Ada plans to conduct
 field tests  of site  characterization methods and
 accelerated pump-and-treat technologies and  eval-
uate other removal technologies, such as horizontal
wells.

     The effort will consist of: a guidance docu-
ment for characterizing a DNAPL site; site charac-
terization of ground-water flow and transport in
fractured rock systems; supercomputer simulation
of pump-and-treat remediation; evaluation of tech-
nologies for cleanup of contaminated sites; investi-
gation of surfactant enhanced remediation; surfac-
tant-enhanced remediation of subsurface  DNAPL
contamination;  surfactant solubilization  of non-
aqueous phase chemicals; evaluation of an enhan-
ced pump-and-treat system using RSKERL's large
physical models;  and analytical chemistry support
for in-house pump-and-treat research.

     Vapor Phase Extraction Techniques

     Most contaminant recovery processes involve
removal of contaminants through the water phase.
However, particular  classes  of contaminants may
be extracted more effectively through their vapor
phase.  RREL-Cin is examining data generated on
major contaminant groupings to  determine which
contaminants can  be recovered  effectively  from
unsaturated zones in the vapor phase.   Promising
vapor-phase recovery technologies being evaluated
include soil  vacuum  extraction  for  recovering
VOCs and techniques that can be combined with
vacuum extraction to increase recovery of VOCs,
such as radio frequency heating and steam injec-
tion.

     RSKERL-Ada is investigating  the  movement
of VOCs during forced-air ventilation of the unsat-
urated zone.  Physical properties of the soil, such
as porosity, pore size distribution, and water con-
tent,  are the primary limits to  the transport of
vapor-phase VOCs in the unsaturated zone.  The
impacts of these properties on vapor-phase move-
ment of contaminants will be determined in lab-
oratory  studies and  the  results will be  used in
models for designing remediation systems.

     SVE is in wide use for removing VOCs from
soil.  RREL-Cin has developed a new procedure to
determine the extent of hydrocarbon removal .from
soil by  SVE  and  the reduction of aqueous solute
teachability  of residual  hydrocarbons: following
SVE.  This procedure uses aqueous leaching and
toxicity characteristic leaching procedure (TCLP)

-------
20
GROUND-WATER RESEARCH DESCRIPTION
methods to determine the concentration and com-
position of solutes.  Remediation experiments are
being conducted in two large experimental aquifers
at the Oregon Graduate Institute  to  examine  an
integrated SVE  system  for removing  VOCs from
sand  and gravel media.  SVE has also received
attention at RSKERL-Ada, particularly with respect
to geochemical controls on SVE processes and to
the combination of the technology with subsurface
biodegradation.

     Bloremedlatlon

     Microbial degradation treatment systems (bio-
systems) use microorganisms  to break down haz-
ardous  wastes to non-hazardous compounds.  Bio-
systems offer the capability  of  using the  broad
versatility of microorganisms for degrading mixed
wastes;  the ability  to  tailor  treatment  processes
toward specific  compounds or  groups of  com-
pounds at specific sites; the potential to eliminate
soil excavation and transportation costs; and  the
minimization of air emissions caused by the move-
ment of contaminants.

     ORD's   biosystems  research  program  for
Superfund includes the development of systems for
in situ aquifer  remediation and  on-site treatment
applications.  Only  in  situ biosystem applications
are included in this ground-water research descrip-
tion.   Biosystems research is a  centrally  coor-
dinated, multi-laboratory program combining  the
 capabilities  of  RREL-Cin,  RSKERL-Ada,   and
ERL-Athens.

     RREL-Cin conducts two  projects to develop
 innovative in situ biosystem  applications.  In the
 first,  laboratory  and  field testing is being  con-
 ducted to determine the potential for the bacteria
 EM4100, genetically engineered by General Elec-
 tric, to degrade polychlorinated biphenyls (PCBs)
 in  Superfund  soils.    The  comparison  of  this
 organism  to the performance  of Pseudomonas
 putida will  enable  the first analysis  of a native-
 versus a recombinant-DNA organism for degrading
 PCBs on soils. RREL-Cin's other project involves
 the design of an in situ soil contamination treat-
 ment  technology using  the white  rot fungus,
 Phanerochaeta   chrysosporium.      Bench-scale
 studies will be designed to determine its ability to
 degrade pentachlorophenol  (PCP)  and  selected
 major constituents of creosote through the use of
                     carbon-labeled  substrates  and measurements  of
                     resulting carbon dioxide concentrations.

                          RSKERL-Ada, in cooperation with the  U.S.
                     Coast Guard at the Traverse City, Michigan, Coast
                     Guard Station, is completing combined laboratory,
                     field, and modeling studies on the effect of enhan-
                     cing natural microbial aerobic degradation  pro-
                     cesses to remediate fuel spills.   Research on en-
                     hanced natural microbial degradation of a gasoline
                     spill by the  addition of hydrogen peroxide and a
                     jet fuel  spill by  addition  of nitrate to the ground
                     water  is being  studied.    Recovery  wells  have
                     demonstrated reclamation  of any existing nitrate
                     not consumed by subsurface bacteria.  Laboratory
                     test results and data from characterization of the
                     site were used to identify and evaluate the hydro-
                     logical,  chemical, and biological parameters that
                     control  in situ microbial remediation.   The  field
                     studies  were used  to evaluate BIOPLUME  II, a
                     mathematical model  of in  situ microbial remedi-
                      ation  used to  estimate the  time  and cost of re-
                     turning  a site to  a specific level of restoration.  A
                      final report on in situ remediation of the gasoline
                      spill has been completed and a final report is  being
                      prepared on results of the jet fuel spill cleanup.
                      The progress  of the  field demonstrations  were
                      followed  and  the  results  compared  with model
                      projections.   The  model  can be used  to design
                      biorestoration  projects at  other sites.  RSKERL-
                      Ada  has  begun additional bioremediation  field
                      demonstrations at  the Park City, Kansas site  to
                      evaluate denitrification techniques  for  bioreme-
                      diation of a refinery spill.  The site has been cored
                      to estimate  the quantity of hydrocarbon to be re-
                      mediated, and twelve monitoring wells  have been
                      installed.

                          Research  is being conducted to  develop  an
                      understanding of the properties of microorganisms
                      and subsurface materials that determine whether a
                      particular site will be colonized by contaminant
                      degrading microorganisms.  Related research is de-
                      fining the environmental factors  affecting the sur-
                      vival and transfer of the genetic elements from
                      genetically  engineered microorganisms in the sub-
                      surface environment.  This information is used to
                      develop methods  for predicting the transport  of
                      microorganisms and their genetic elements for use
                      with bioremediation techniques.

                           The discovery of extensive anaerobic bacteria

-------
                                GROUND-WATER RESEARCH DESCRIPTION
                                            21
in the subsurface has led to increased interest into
their use in remediation of contaminated  sites.
RSKERL-Ada recently completed a project to de-
termine the capacity of microorganisms in aquifers
to transform monoaromatic (single benzene ring)
hydrocarbons in the absence of oxygen.  This in-
formation will be used to predict the influence of
the geochemical environment, particularly the pre-
sence of iron  phases,  on biotransformations of
hazardous   organic  compounds   in  subsurface
materials.

    ERL-Athens is conducting experiments to de-
termine  the  extent to  which sorption processes
affect the degradation of specific classes of hazar-
dous organic chemicals and to determine if the ad-
dition of emulsifying agents can enhance  bioreme-
diation.  The degradation rate of sorbed or highly
insoluble  substrates can be  increased  by making
the  substrates   more  available  to  the micro-
organisms.  ERL-Athens is examining the effects
of emulsifiers on the degradation of insoluble com-
pounds, including 4-chlorophenol, chlorobenzenes,
and polyaromatic  hydrocarbons  (PAHs)  and  en-
hancing the degradation of PCB mixtures.   The
results  of these experiments will be used to devel-
op mathematical models to predict the effects of
emulsifying  agents.

    The  Office of Solid Waste  and Emergency
Response (OSWER)  and  ORD  have jointly
instituted  a  Bioremediation  Field  Initiative to
provide assistance to the Regions in conducting
field  tests  and  evaluating  bioremediation   site
cleanups  in  Superfund, RCRA,   Underground
Storage Tank (UST), and state non-NPL sites.  The
initiative  is   designed   to   fully  document
performance  of full-scale field  applications of
bioremediation, provide technical assistance to sites
in a feasibility or design  stage, and  regularly
provide   the   Regions   with   information  on
treatability studies, design, and  full-scale  opera-
tions of bioremediation  projects  in  the  Regions.
Over  140 sites have  been identified nationally
where  bioremediation is being planned or where
full-scale systems have  been  put  in  place.
Presently, eight sites are undergoing performance
evaluations  under  the initiative,  providing  an in-
depth analysis  of  process efficiency.  The waste
types   include  petroleum   products,   creosote,
solvents, and PAHs.
    , One  of  the  most  difficult  ground-water
remediation  problems   is   contamination   by
DNAPLs.  Common DNAPLs that are hazardous
constituents include solvents, wood preservatives,
coal tars, and certain pesticides.  RSKERL-Ada is
currently  studying  the   feasibility  of  DNAPL
removal by air-sparging  from the bottom  of the
water table.  Once experimental data have been
collected,   the   data  will  be   integrated  into
conceptual models for larger scale studies.

     Underground   Storage  Tank   Remediation
     Research

     Several hundred thousands of USTs contain-
ing petroleum products and hazardous materials are
leaking, posing  a serious threat to the nation's
ground-water supplies, and  to public health and
welfare.   The  1984  Hazardous  &  Solid  Waste
Amendments to  RCRA mandated that EPA regu-
late these UST systems, and develop guidelines to
administer the Leaking Underground Storage Tank
(LUST) Trust Fund established under CERCLA to
finance corrective  actions at LUST sites.   EPA's
Office of Underground Storage Tanks (OUST) was
established to develop regulations and implement a
national program to prevent and clean up contami-
nation from leaking USTs. RREL's UST program,
which is located at the Edison Laboratory in New
Jersey, was established to provide technical support
to OUST, specifically in rulemaking under RCRA
Subtitle I and in implementing the provisions  of
the LUST Trust Fund under CERCLA. The overall
approach has been to evaluate prevention,  detec-
tion, and corrective action technologies to identify
cost-effective and  reliable techniques and  equip-
ment for LUSTs and to  provide technical assis-
tance on site assessment decision tools and clean-
up  technologies  for LUST  Trust Fund program
guidance and implementation.

    Research and  demonstration activities will be
conducted at the Edison Laboratory on techniques
and equipment  to: improve determination of site
conditions in preparation for site remediation; more
quickly design and install UST remediation hard-
ware; achieve  complete  site remediation  more
quickly by improving contaminant removal both in
situ and above ground; provide cheaper treatment
alternatives  for  UST   remediation  side-waste
streams; and confirm the progress and completion
of UST remediations.  Cleanup technologies devel-

-------
22
GROUND-WATER RESEARCH DESCRIPTION
oped  for  petroleum  and  hazardous  chemical
releases under RCRA and CERCLA will be eval-
uated  and  optimized.    Outputs  will  provide
information and assistance to EPA, state, and local
agencies, and practicing professionals  concerning
cost-effective,  site-specific  decisions  about  the
need, degree and type of cleanup required, and will
transfer corrective action technologies to the user
communities.

    Pilot scale experiments are being conducted
for optimizing and enhancing soil vapor extraction
system design and operation, including air sparging
and aquifer heating techniques.  Other pilot scale
research includes in situ bio-venting and ex  situ
bio-oxidation  processes  for  treating petroleum
contaminated soil. The Edison Laboratory is also
conducting research on pulsed pumping techniques,
water table manipulation, and thermal desorption
to treat petroleum contaminated soils at LUST sites
and initiate  assessment for chemicals found at
LUST sites.

Underground    Injection   Control
Research

     In addition to the  geophysical research work
conducted  at EMSL-LV for the  UIC  program,
additional  underground injection control  research
focuses on the evaluation of methods to prevent
toxic substances from entering aquifers that supply
drinking water.  This  research is conducted by
RSKERL-Ada and emphasizes techniques to pro-
tect ground water from underground injection of
wastes through Class I and Class V injection wells.
Class I injection wells  are those where municipal
and industrial wastes, including hazardous wastes,
are injected deeply into the  subsurface below aqui-
fers that can potentially be used to supply drinking
water.  Class  V wells include  a  wide variety of
injection  wells  where  waste  waters  are often
injected into  ground-water containing  aquifers.
 Class V  wells include agricultural, storm-water,
 and  industrial drainage  wells;  septic  systems;
 wastewater treatment plant  effluent disposal wells;
 industrial process water wells; automobile service
 station disposal wells;  aquifer recharge wells; and
 abandoned drinking water wells.
                          Hazardous Waste Injection Methods for Class I
                          Wells

                          There are a number of unresolved scientific
                     questions regarding the risks involved with dispo-
                     sal of wastes through Class I underground injection
                     wells.   RSKERL-Ada has  completed  a research
                     project to  determine  the movement of injected
                     fluids and the integrity of confining layers of sub-
                     surface rocks.   Research is being conducted on
                     methods for determining the mechanical integrity
                     of injection wells and the effectiveness of methods
                     for plugging abandoned wells.

                          The mechanical integrity  of injection wells
                     constructed of various materials are being tested to
                     develop methods for determining if wells are leak-
                     ing  into underground sources  of  drinking water.
                     Two research wells have been  constructed to pro-
                     vide a means  for conducting field  tests of specific
                     mechanical integrity  equipment.   Tests are being
                     conducted  on each well  to evaluate  the ability of
                     various down-hole tools to determine the quality of
                     the  cement bond between  the cement and the
                     casing, detect the movement of fluid behind the
                     casing, and test the integrity of the tubing,  casing,
                     and packers.   A third well, installed  using  fiber
                     glass casing and intentional imperfections, will be
                     used to determine the sensitivity of logging  tools  ,
                     to detect these imperfections.            ;.-.;/ •;,...

                          RSKERL-Ada is studying  the effectiveness of
                     plugging abandoned wells  with drilling  mud to
                     prevent the migration of injected hazardous wastes
                     upward through the wells to potable ground-water
                      supplies.  An instrumented test well is being used
                     to  determine  the  effect pf  temperature,  time,
                     pressure, and composition pn the  strength pf mud
                     plugs  and  to evaluate techniques to enter previqus-
                      ly plugged abandoned wells to determine the effec-
                      tiveness of plugging materials used.

                          Class V Well Injection Methods

                          There are an estimated 170,000 Class V wells
                      in  the  United States.   Many of these are un-
                      regulated.  RSKERL-Ada is conducting research to
                      determine the impact of Class V wells on the envi-
                      ronment and  methods for improving Class V injec-
                      tion well practices.   Background information on
                      the impact of current Class  V well design, use, and
                      effects on ground-water quality is being compiled.

-------
                                GROUND-WATER RESEARCH DESCRIPTION
                                            23
Information is also being developed on the trans-
port and fate of contaminants introduced into the
subsurface via Class V injection wells, focusing on
those well  classes presenting high potential for
ground-water contamination.  Methods and criteria
for regulating Class V wells will be developed
from this information^

Technology  Transfer  and  Technical
Assistance

    Technology transfer and technical  assistance
are key elements of ORD's research program and
are integral parts of all laboratory activities.

    Technology transfer is a cyclical process that
incorporates the assessment of specific user needs,
development of research results in a format tar-
geted to specific  audience needs,  timely dissem-
ination   of  the   technical  information,   and
evaluations  of  whether, or  not  the  technical
information satisfied user needs.   ORD ground-
water technology transfer audiences include EPA
headquarters;  EPA  Regional,   state,  and  local
regulatory, .enforcement,   and   permitting  staff;
academia;   independent  consultants;   regulated
industries;  trade   associations;   and the  general
public.  Technology transfer mechanisms include
manuals,  research symposia,  conferences,  and
handbooks on  the use  of state-of-the-art  tech-
nologies, journal articles, fact sheets on topics of
special interest, modeling packages with manuals
for their proper use, training courses,  seminars,
video tapes, electronic bulletin boards, and techni-
cal information clearinghouses.   The transfer of
research results is considered an integral part of
each ORD research project. Technology transfer is
coordinated through CERI in Cincinnati, Ohio.

    Technical assistance is the direct, person-to
person transmission of  scientific and  engineering
information to help specific users apply state-of-
the-art technologies and  procedures  to specific
problems in the field.  Technical assistance is pro-
vided upon request to  EPA headquarters and Re-
gional staff. Each  of the four ORD laboratories in-
volved in  ground-water research  have staff  de-
dicated to providing technical assistance or direc-
ting requests to appropriate  experts.   Many re-
searchers are contacted directly based on their pub-
lications and through the ORD Ground-Water Re-
search  Technical  Assistance   Directory   (see
appendix B).

     Technology transfer and  technical assistance
ensure that RCRA, Superfund, drinking water, and
pesticide .regulatory   approaches   to  .protecting
ground-water quality  incorporate the latest scien-
tific   information   on.   subsurface    processes,
remediation monitoring methods and equipment,  It
also ensures that permitting, remedial, and enforce-
ment  actions  are   scientifically   credible  and
defensible.  ,  Technology transfer  and technical
assistance projects are conducted under the Super-
fund  and  drinking water  programs.    Technical
assistance ,is also provided  for the  RCRA and
pesticides programs  as integral  parts  of research
projects.

     ORD  and OSWER have jointly  established
Technical Support Centers (TSCs) at the four ORD
laboratories involved in ground-water research: the
Ground  Water  Fate and  Transport TSC  at
RSKERL-Ada;   Monitoring  and   Site   Charac-
terization TSC at EMSL-LV; Exposure  Monitoring
and Ecological  Risk Assessment  TSC at ERL-
Athens; and Engineering and Treatment  TSC  at
RREL-Cin.   The TSCs,  in  response to Regional
Superfund staff requests for assistance,  provide di-
rect technical expertise in the field,  review site
technical reports, conduct workshops on emerging
issues, and maintain technical information clearing-
houses. A parallel program for  RCRA corrective
action staff began in FY91.

     Geophysical Technical Support

     EMSL-LV provides technical assistance and
training on  the use of geophysical techniques  to
characterize Superfund sites, conduct field investi-
gations, and review reports and workplans.  Geo-
physical support encompasses  the use  of seismic,
electromagnetic  induction,  resistivity,  magneto-
meters, groundpenetrating  radar,   and borehole
electromagnetic induction techniques.   Technical
support on  the use of additional  methods can also
be  provided through cooperative agreements with
the USGS and the U.S. Army Corps of Engineers.

     Transport   and  Transformation   Technical
     Support

     RSKERL-Ada  has  developed  an  interdis-
ciplinary team  of  ground-water  contamination

-------
24
GROUND-WATER RESEARCH DESCRIPTION
experts  who  provide  site-  and  case-specific
technical assistance to Superfund Regional staff on
a when-and-where-requested basis.  Through the
Ground-Water Fate and Transport TSC, RSKERL-
Ada helps field staff assess the extent of ground-
water contamination,  predict the  transformations
and movements of contaminants in the subsurface,
and  evaluate in  situ aquifer remediation options.
The team  also develops training and seminar ma-
terial in cooperation with  CERI and serves as an
Interface between the ground-water research com-
munity  and EPA, state, and local  staff actively
involved in dealing with contaminated sites.

     In  addition to  direct  technical  support,
RSKERL-Ada's  technical  assistance team partici-
pates in relevant research projects in order to pre-
sent existing state-of-the-art technical  information
in a user-friendly format. RSKERL-Ada has com-
pleted consolidation  of materials on the use of a
USGS  solute transport model  (MOC) and is
working on the  development of a user-friendly
software package to allow easy use and interpreta-
tion of an unsaturated zone organic phase contam-
inant transport model (ContPro).  A report inten-
ded to  provide  new Superfund field staff with
introductory information on ground-water modeling
needs,  responsibilities,  and  guidance has  been
completed.  Another manual is under development
to provide guidance to  field staff on  site-specific
field techniques  for quantifying the physical and
chemical properties of contaminated heterogeneous
aquifers,  including  data  needed  for  modeling
contaminant behavior.  The RSKERL-Ada team is
also  modifying   existing  geostatistical  computer
programs  now being used by researchers so that
they are useful  to  field staff who do not have
extensive   training   in   geostatistical  methods.
Finally,  a  manual  that  consolidates  existing
information on the use of pump-and-treat methods
is under development, with particular emphasis on
estimating the length of time required  for a pump-
and-treat system to remediate a contaminated site.

     ERL-Athens established the Center for Expo-
sure Assessment Modeling (CEAM)  in 1987 to
facilitate the use of models that can estimate con-
taminant exposure through ground water and other
sources.  The Exposure Modeling and Ecological
Risk Assessment is a part of CEAM and provides
exposure  assessment assistance to Superfund  and
RCRA  staff.  CEAM also provides technical assis-
                     tance to all EPA programs and will perform about
                     40 assessment projects during FY92,

                         Direct technical support is provided by ERL-
                     Athens at specific sites, with  emphasis on multi
                     media assessments and the uncertainties associated
                     with model estimations.  The results of the more
                     intensive site support  projects  are developed into
                     case studies for use as training aids and as tech-
                     nology transfer documents.

                         ERL-Athens   also   provides   rate  and
                     equilibrium constants necessary for predicting the
                     fate and transport of organic chemicals in  ground
                     water.  Values judged to be the best are available
                     for parameters  such as hydrolysis  rate, octanol/
                     water  partition  coefficient,  and  solubility  are
                     provided upon request.  Data  are extracted from
                     the literature and carefully screened for validity,
                     computed  by ERL-Athens,  or measured  in  the
                     Athens  Laboratory.   Data considered  to be  of
                     adequate  reliability are entered into the FATE
                     database, which is being developed by the Labora-
                     tory.

                          RSKERL and ERL-Athens are also working
                     directly with OSWER on two projects  involving
                     the application of subsurface  fate  and transport
                     models. In one, ORD has been asked to advise the
                     Superfund program on the use  of unsaturated zone
                     models for setting soil clean-up levels at Superfund
                     sites based on potential leaching of soil contami-
                     nants to ground water. In a second project, ORD
                     has been asked by OSW to assist in the Regulatory
                     Impact Analysis for new corrective action rules for
                     solid waste  management units.   This involves
                     selecting and applying a multi-media model, which
                     includes the ground-water transport pathway, to
                     estimate the  human health and environmental im-
                     pact of corrective action regulatory alternatives.

                          Aquifer Remediation Technical Support

                          RSKERL-Ada has established the Subsurface
                     Remediation Information Clearinghouse (SRIC) to
                     help transfer information on technologies for clean-
                     ing  up contaminated ground  water and  soils to
                     Superfund remediation field staff.  The emphasis
                     of the clearinghouse is on in situ technologies such
                     as microbial remediation and  specialized pumping
                     techniques.  The clearinghouse includes informa-
                     tion  on  transport  and transformation  processes,

-------
                                  GROUND-WATER RESEARCH DESCRIPTION
                                                                                                   25
 remedial technology evaluations, guidance on the
 use of remedial technologies, case histories,  and
 related research publications.   Information to be
 included in  the  clearinghouse  is evaluated  by
 RSKERL-Ada staff and experts  in other agencies
 and universities for its benefit to  users.  A protocol
 for evaluating  the  performance of ground-water
 remediation activities at Superfund sites is being
 developed for inclusion in the SRIC.  Case studies
 of selected Superfund sites are being conducted to
 investigate the effectiveness of modeling and mon-
 itoring approaches.  SRIC  staff disseminates infor-
 mation in  the  clearinghouse,  conducts literature
 reviews, and provides information services to EPA,
 other  federal and state agencies, and  researchers.
 OHEA provides technical support at Superfund
 sites through site assessments and remedial investi-
 gations,

     OHEA also sponsors remedial  work related to
 karst aquifers, which are  aquifers  where  flow is
 appreciable through  fractures,  other  joints, and
 bedrock—any or all of which have been enlarged
 by solution of bedrock.  One of the biggest chal-
 lenges faced in karst aquifer remediation is finding
 ways to cleanup contaminated karsts, and there is a
 need for the development  of karst  aquifer protec-
 tion methods, and ground-water monitoring within
 karst aquifers.

     Training and Model Evaluation

     RSKERL-Ada provides technical support and
 evaluations  of models  for the   investigation,
 management, and protection of ground-water sour-
 ces of drinking water.  A  series  of narrated slide
 presentations have been developed for use as self-
 training aids to  help field  staff keep abreast with
 new research findings and  technologies.  Modules
 that have been completed  include  basic geology,
 fundamental   hydrogeology,  monitoring   well
 installation,  ground-water  models, ground-water
 contamination,  and   ground-water   sampling.
Training courses are  also  provided  periodically
 upon request.

    RSKERL-Ada has developed a close relation-
 ship with the International Ground-Water Modeling
 Center  (IGWMC)  at me  Colorado  School  of
Mines.  The school  operates a clearinghouse for
technical information on the use  of mathematical
transport and transformation models and software.
 The two major tasks of the clearinghouse are the
 dissemination of ground-water models and  infor-
 mation on their application and the distribution and
 support of modeling software. The Center regu-
 larly offers short courses and  seminars on the use
 of models  and carries out a research program to
 evaluate  the quality  of the  confusing  array  of
 existing ground-water transport and transformation
 models.

     Superfund   Technical  Assistance   Response
     Team

     The  Technical  Support  Branch in  RREL-Cin
 provides  the Regional Superfund Offices  with en-
 gineering technical assistance to Remedial Project
 Managers on problems arising during the reme-
 diation of individual sites.  In terms of site specific
 assistance,  RREL-Cin organized  the  Superfund
 Technical Assistance Response team  (START).
 The START program provides site specific,  long-
 term technical assistance to  a limited number of
 Superfund sites  that have  been selected by the
 Regional  Offices in  conjunction with ORD.  Sites
 selected for the START program receive  compre-
 hensive engineering  assistance  on multiple phases
 of  the   remedial  investigation  and  feasibility
 (RI/FS) process.  The Engineering Technical  Sup-
 port  Center (ETSC) also provides  similar  site-
 specific assistance, but the focus of this center is
 on quick response and short term assistance.

     The  START program deals  primarily  with
 complex sites that have high regional priority  rela-
 tive  to the  selection of technologies  available to
 the program,  but  in FY91, the program  will  be
 limited to handling 45 sites per year.  START has
 first  priority on available technical support capaci-
 ty. .'    .                        ,           .  -   :

     The  START program has been using the
 Computer Assisted Site Evaluation (CASE) system,
 developed by RREL-Cin, to provide technical sup-
port  to Regional Projects Managers in the assessr
ment and  remediation of  contaminated  sites.
 CASE is a computer system  that has been devel-
oped  to  improve and  expedite the process  of
hazardous waste  site  assessment.   The  system,
based at EPA's Center Hill Facility, is available as
 a  service  to  the  Regions.   Capabilities of the
system include; 3-D spatial modeling of  the site
geology,   hydrogeologic  cross-sectioning,   con-

-------
26
                               GROUND-WATER RESEARCH DESCRIPTION
taminant  concentration  mapping,   contaminant
volume calculation, ground-water modeling, and
modeling of various remedial actions. The system
has  been  applied  to  four Superfund  sites  in
Pennsylvania, Florida, Washington, and Ohio, and
is ready to be applied in the Regions.

     RSKERL-Ada  provides technical assistance
through their Center for Subsurface Modeling Sup-
port (CSMoS).  This Center is for model technical
assistance. They distribute and service all models
and databases  developed by  RSKERL-Ada  and
also provide general support on model application
to vadose  zone and  ground-water contaminant
transport problems.

     Forum Issue Papers

     OSWER and ORD established the Superfund
Technical Support  Project  (TSP)  in   1987 to
provide technical assistance to RPMs and  OSCs.
The  Forums,  TSCs,  and OSWER's Technology
 Innovation Office frequently discuss Superfund site
 problems and  successes,  useful technologies and
 procedures, technical  needs,  and current  ORD
 research, development, and demonstration projects.
 TSP  efforts are communicated to the Regions
 through  the   Ground  water   and  Engineering
 Forums,  which  are comprised of  one  or more
 professionals   from the  Superfund, and  RCRA
 Corrective Action programs in each of EPA's ten
 Regions.  These  Forums  exchange  up-to-date
 information related   to  remedial  activities  at
 hazardous waste sites and  are committed to the
 identification  and  resolution  of engineering  and
 ground-water issues impacting  remediation.  The
 Forums propose topics and set priorities for poten-
 tial issue papers and work with  the Centers in
 developing issue papers and conducting workshops
  on emerging technical topics.  The TSP improves
  communication  of technical information and the
  consistency of Superfund 'site remedial actions.

       Forum Issue Papers were initiated as a means
  of addressing a number of technical issues identi-
  fied by the Forums as critical to remediation deci-
  sions.  These documents are intended to be brief,
  readable summaries  of the current state-of-the-
  science  of particular technical issues. For  a listing
  of current ground water related issue papers, see
  Appendix C.
Relationship of ORD Research to Other
Ground-Water Research In EPA

    In addition to ground-water research conduc-
ted by ORD  and coordinated by EPA's research
committees, EPA program offices sponsor a signi-
ficant amount of research  at ORD's laboratories,
conduct research through program office contrac-
tors for short-term data needs, and synthesize cur-
rent knowledge into technical guidance documents.
A major example of program offices co-sponsoring
ORD research is the support of OSW and OPP for
exposure assessment modeling at ERL-Athens. In
addition, ORD laboratory  directors and staff fre-
quently contact  program office  clients  to better
understand program and research needs.  The pro-
gram offices, particularly OGWDW and OSWER,
also  have  increased  activities  to provide  direct
technical assistance to Regional and state staff.

     OGWDW  develops  and  transfers  existing
knowledge and methods to state and local agencies
for protecting ground-rwater  sources of  drinking
water.  Because the states develop and  implement
their own ground-water protection programs under
EPA leadership, OGWDW has concentrated on
 providing policy, program management, and tech-
 nical guidance to the states. Much of this  work
 involves the collection of existing technical infor-
 mation on hydrogeologic assessment and; pollutant
 source management tools that have already proven
 effective in other roles and putting this information
 into a format  appropriate for various state and
 local audiences. In  addition, OGWDW conducts
 pilot studies, workshops,  and.training programs
 with states and  local  governments.

      The Office of Policy, Planning, and Evalua-
 tion (OPPE) has been involved with ERL-Athens
 in the  development  of  a linked economic and
 ground, surface, and air modeling system  called
 the Comprehensive Economic Environmental Poli-
 cy Evaluation  System (CEEPES).   CEEPES  is
 being developed under a  cooperative agreement
  with the Center for Agricultural Research Develop-
  ment at Iowa State  University.  USDA is contri-
  buting staff resources to  the effort and USGS is
  conducting  monitoring to help verify  the system.
  The system will be used to  evaluate alternative
  agricultural policy and management systems.

       OHEA has designed the Integrated Monitoring

-------
                                GROUND-WATER RESEARCH DESCRIPTION
                                            27
Evaluation System  (IMES) for assisting users  in
choosing appropriate ground-water models.  Each
user defines his criteria and the system will search
for models  that fit user-defined needs.   Version
one  of IMES was developed  in FY91 and is cur-
rently  being  reviewed.    The  system  includes
models  for four media:  ground  water,  surface
water, non point source, and  air, and all models
included in the system have been used by EPA.

Coordination Among Federal Agencies

     The Federal Coordinating Committee for Sci-
ence, Engineering, and Technology (FCCSET) of
the Office of Science and Technology Policy in the
Executive Office of the President  has drafted its
final report on  federal ground-water research—
Federal Ground-Water  Science and  Technology
Programs: The Role of Science and Technology in
Addressing Four Key National Ground-Water Is-
sues (May, 1991).  The  report is intended to help
government officials understand federal research
efforts that address Congressionally mandated pro-
grams   involving   ground-water   assessment,
management, and protection.

     This report  relates the ground-water research
and  engineering  described in  the earlier Subcom-
mittee report, Federal Ground-Water Science and
Technology Programs:  The Role of Science and
Technology  in the  Management of the Nation's
Ground-Water Resources,  to  four ground-water
issues thought by the Subcommittee  to be  most
critical to  the Nation: ensuring long-term ground-
water supplies; remediating contaminated ground
water;  minimizing  agricultural contamination of
ground water; and disposing of nuclear waste.

     Recent ground-water development trends sug-
gest  the critical need to manage existing ground-
water supplies  and to protect ground-water quality.
Ensuring that ample ground water is available for
use where it is needed both now and in the future,
and taking into account the physical limitations of
the natural system is an important policy objective
of the FCCSET  report.  Other objectives include
ensuring that ground water is of suitable quality
for current and future uses, and developing a better
scientific base  for the management of water quality
and  quantity. Priority research goals in support of
these policy objectives include improved: manage-
ment strategies to control the sources  of contami-
nation;  understanding  of  the  impacts  of various
land uses on ground-water quality; models to pre-
dict the transport  and fate of various pollutants,
coupled  reaction-flows, and  the flow of water
through fractured rock and karst terranes; data on
the kinetics of mineral-water reactions; data on the
kinetics of the interactions of toxic substances  with
geologic materials; inductive methods to eliminate
or  reduce the  need for  expensive   observation
wells; and sampling and data analysis techniques.

     EPA and other federal agencies involved  in
ground-water research employ  a number of mech-
anisms to coordinate their  research and  technology
transfer programs, including:

 *   Specific interagency delegations of  authority
     to provide lead agency coordination;

 *   Memoranda of Understanding  (MOUs)  that
     set forth specific responsibilities and areas of
     cooperation;

 *   Standing and ad hoc committees and technical
     workshops to monitor agreements and share
     information;

 *   Jointly conducted projects or programs  that
     employ  the  combined  expertise  of several
     agencies;

 *   Cooperative research that is jointly funded by
     federal and state governments;

 *   Interagency coordination  that occurs at the
     scientific planning level; and

 *   Interagency cooperation to validate models.

     EPA and USGS signed a MOU in August,
1981, providing an  umbrella  under which each
agency's programs  are coordinated.   A second
MOU was signed in  June, 1985,  to  coordinate
ground-water data collection and technical assis-
tance. EPA and USGS regularly exchange visiting
scientists and participate in each other's technical
meetings on ground water.  In addition, the  two
agencies have established  a bilateral committee to
coordinate their respective research  programs and
prevent  duplication of effort.

     EPA and USDA signed an interim MOU in

-------
28
GROUND-WATER RESEARCH DESCRIPTION
October,  1988,  providing an umbrella agreement
for coordination in surface and ground-water qual-
ity improvement and maintenance.  Through the
MOU, the Office of Water (OW) uses the expertise
of USDA's Soil Conservation Service to increase
technical assistance to  states in the development
and  implementation  of state-wide water quality
programs and projects.   EPA also participates on
an interagency  committee  to  guide the  water
quality  research  of  USDA's  Cooperative  State
Research Service.

     During  FY90, USDA disseminated Requests
for Proposals that were prepared by Project Inves-
tigators to identify areas for experimentations and
monitoring.  The first full year of project operation
was  devoted to preparing project sites and charac-
terizing area conditions.  The committee, coordi-
nating mechanisms, and management  systems will
implemented.  The Water Quality Working Group,
which is chaired by the USDA, is responsible for
the  monitoring and  directing  of the President's
Water Quality Initiative in its entirety. The MSEA
project  is  under the  purview of this working
group's research Task Group.  The responsibilities
of this task group include  interpreting  goals and
objectives and  ensuring continued cooperation of
participating agencies; supporting the MSEA pro-
ject  in achieving its objectives; ensuring coordina-
tion of MSEA project participants, and developing
recommendations and modifications to the MSEA
workplan as needed to  achieve the broad goals of
the MSEA program.

     USDA and EPA are also working together on
an FY93 initiative, Environmental Quality in Agro-
ecosystems, for  reducing ecological impacts of
agricultural  practices and making food consump-
tion safer.  USDA is increasing its efforts on re-
ducing the environmental impacts from agricultural
production,  and EPA needs to play an active role
in incorporating  environmental quality objectives
into agricultural production practices. This  agro-
ecosystem initiative  builds  on the MASTER pro-
gram, and expands joint work between EPA and
USDA to ensure that changes to  agricultural pro-
duction  practices over  the next decade result in
meaningful, cost-effective improvements  in envi-
ronmental quality. USDA expertise on agricultural
production  and EPA expertise on environmental
protection need to be blended toward this common
 goal.
                         Interagency  coordination   between   the
                     Department of Energy's (DOE's) Office of Energy
                     Research,  USGS, EPA,  and other agencies is
                     predominantly  at the scientific  planning  level.
                     Since 1983, DOE has sponsored over 20 meetings
                     to  assist in setting  scientific direction for  its
                     fundamental research  programs.    All  federal
                     agencies have  participated  in  Office of Energy
                     Research reviews, providing program coordination
                     and information exchange.  Also, EPA and DOE
                     signed an MOU in January 1990 for joint research
                     on radioactive  or mixed-waste  sites.  This  MOU
                     provides  new  opportunities  for  cooperative  re-
                     search on contaminant treatment systems as well as
                     subsurface research projects.

                         In addition to coordinating research with other
                     federal agencies through interagency agreements
                     and coordinating committees, EPA conducts joint
                     ground-water research projects with  the USDA,
                     USGS, U.S. Air Force, U.S. Army, U.S.  Coast
                     Guard, U.S. Navy, DOE, National Research Coun-
                     cil, and the Tennessee Valley Authority.

                     External Research Reviews

                         Several major documents  have been written
                     with recommendations for research needed to im-
                     plement the Agency's multiple mandates for  pro-
                     tecting ground-water  resources.  The Science Ad-
                     visory Board distributed its Review of the EPA
                     Ground-Water Research Program in July, 1985.
                     The  Hazardous Waste Ground-Water Task Force
                     distributed  an Evaluation of the RCRA Subpart F
                     Ground-Water Monitoring Program in  February,
                     1986,  and  its  final  report  Hazardous  Waste
                     Ground-Water Task Force:  1987 Status Report in
                     October, 1988.   Two other reports contained rec-
                     ommendations  on the development  and use  of
                     ground-water  models:   the  Science  Advisory
                     Board's  Resolution  on  Use  of Mathematical
                     Models by EPA for Regulatory Assessment and
                     Decision Making (January, 1989) and the National
                     Research Council's Ground-Water Models:  Scien-
                     tific  and  Regulatory   Applications  (November,
                     1989).

                          The Science Advisory Board's 1985 review of
                     EPA's ground-water research program recommen-
                     ded the creation of  a strong central  direction for
                     the research program, increased resources for train-
                     ing and technology  transfer, proactive research on

-------
                                GROUND-WATER RESEARCH DESCRIPTION
                                            29
ground water contamination sources not addressed
by specific mandates, and development of faster
methods  for ground-water sampling and analysis
that maintain data quality.  Funding increases were
also  recommended  in specific ground-water  re-
search areas:  monitoring;  basic transport and fate;
remedial methods  for fractured geologic forma-
tions; and identification of suitable geologic envi-
ronments for isolating hazardous wastes by means
of deep injection wells.

    The Hazardous  Waste  Ground-Water  Task
Force of 1986 considered technical problems  in
ground-water monitoring technology as a  compo-
nent of  their overall evaluation of the  RCRA
Ground-Water Monitoring Program.   Six  techno-
logical needs were identified:  (1) improved under-
standing of the behavior of individual contaminants
and  contaminant classes and sampling strategies
for each class;  (2)  investigation of the  use  of
plume dispersion as a basis  for monitoring well
horizontal spacing,  screen depth, and  length;  (3)
identification of sampling equipment  and  tech-
niques best suited for specific hydrologic  settings
or monitoring needs; (4) estimation of the effect of
sampling equipment on monitoring data; (5) selec-
tion  of key  indicators for  contaminant  classes
according to geological  setting;  and  (6) estab-
lishment of analytic methods for certain hazardous
constituents;

    The Science Advisory Board's  review of the
use of mathematical models in EPA  regulatory de-
cision-making contained recommendations relevant
to ORD development and testing of ground-water
transport, transformation, and exposure assessment
models.  The report  recommends an increase in
validation  of models by laboratory  and  field
studies, increased communication of the sensitivity
and  uncertainty  of environmental model  predic-
tions, and more stringent peer review of models
and  expert systems.   The  National Research
Council's report discussed the scientific bases on
which existing models are  founded, approaches and
philosophies routinely used in the  application of
models   to   regulatory  decision  making,  and
guidelines on the development and  use of models
intended for application to the regulatory process.
In addition to these broad ground-water research
program reviews,  EPA  laboratories   frequently
conduct peer reviews of specific elements of the
research program to ensure the scientific credibility
of research directions and projects.

     ORD is addressing these recommendations to
the extent practicable within its available funding.
Internal EPA reviews  by  the  research committee
are conducted to determine which of the competing
research needs should be addressed.

Internal Research Reviews

     In addition to external reviews of the ground-
water research program, ORD's ground water ma-
trix  manager conducts research program reviews
each year in concert with  the budget development
cycle.  The objectives of the reviews are to eval-
uate research progress and results,  determine whe-
ther planned research projects and their resources
are sufficient to meet the needs  of  Program and
Regional Offices,  decide  whether additional  pro-
jects are  necessary, and  determine  whether  the
timing and substance of planned deliverables are
suitable.

     The  FY91  ground-water  research  program
review was attended by rejpresentatives from the
Office of  Technology  Transfer  and Regulatory
Support (OTTRS),  OEPER, OEETD, OMMSQA,
NCGWR,  program offices,  and  the   Regions.
Research needs  identified at the  review included
work on expert  systems for site  characterization,
application of GIS  to  siting  decisions, and  the
combining  of   ground-water  databases    with
statistical expert systems for better management of
ground-water monitoring data.  A number of other
research needs were raised in the areas of nitrates,
RCRA corrective action, statistical applications for
underground injection control, and demonstrations
of subsurface treatment trains in the field.

     Many of the research needs expressed in these
ground-water research program reviews  are being
addressed by established research programs. Other
needs have not yet been fully addressed  due to
funding constraints and competing priorities.

Research Results

     ORD  has developed  many innovative proce-
dures, methods,  and equipment for advancing re-
search capabilities and the scientific  basis of Pro-
gram and  Regional office regulatory, permitting,
and enforcement programs.  Numerous technical

-------
30
GROUND-WATER RESEARCH DESCRIPTION
articles, handbooks, and technical resource docu-
ments  have  been  published  describing  these
accomplishments.  Appendix C lists major reports
recently produced by ORD's ground-water research
program.

    EPA uses information  systems to disseminate
information to  the Regions and  States.  EPA's
Cleanup Information Bulletin Board system (CLU-
IN), formally named the OSWER Bulletin Board,
is designed for use by hazardous waste cleanup
professionals  to find current events  information
regarding innovative technologies, to consult with
others  who are on-line, and to access hazardous
waste databases. The Alternative Treatment Tech-
nology  Information Center (ATTIC)  system  is
designed to provide technical information on alter-
native  methods of hazardous  waste treatment.
ATTIC is designed for use by site  remediation
managers in the federal, state, and private sectors
to obtain technical information hi the  form of
abstracts or report summaries.  The ORD bulletin
board is operated by  CERI, and contains a data-
base of  over  17,000 searchable  abstracts  of all
ORD  publications,   including   publications   on
ground-water research.

    Within recent years, major research programs
have been initiated in the  areas  of advanced site
characterization and contaminant detection  equip-
ment, monitoring methods,  controlled field studies
of  microbial  degradation  techniques, facilitated
transport processes that enhance contaminant mobi-
lity, methods for incorporating uncertainty analyses
within modeling packages,  pump-and-treat techno-
logies, and wellhead protection methods.  In addi-
tion, ORD has significantly expanded its efforts to
transfer technical information and provide  direct,
site-specific, technical assistance  to  personnel  in
the field.  Reports planned to be completed  in
FY91  and FY92  under these and other important
research programs are listed in Appendix B.

    Despite recent advances in understanding  of
fundamental  subsurface  processes  and ground-
water  monitoring and  remediation  technologies,
many  difficult  questions are just beginning to be
answered.   ORD's future ground-water research
program will address the highest priority of these
questions.
                     Future Program

                         The  two themes  that ORD's future ground-
                     water research program will emphasize are the pre-
                     vention and remediation of ground-water contam-
                     ination.

                         The prevention research program will encom-
                     pass identification of threats to ground water from
                     point and nonpoint sources and mitigation of those
                     threats through improved management of the con-
                     taminant  sources.  OW's wellhead protection pro-
                     gram offers an opportunity to integrate advances in
                     ground-water research  into a comprehensive pro-
                     gram to protect drinking water aquifers.  Improved
                     site-specific methods will be needed to characterize
                     local point and non-point sources of contamination
                     and  define vulnerable  ground-water  resources in
                     order for state and local governments to develop
                     plans for protecting wellheads. The delineation of
                     wellhead protection areas  will require  improved
                     predictive models to account for the effects of sub-
                     surface biological,  chemical, and physical proces-
                     ses on the transport and transformations of contam-
                     inants in the subsurface.  The correct use of these
                     models will depend, in part, on the quality of input
                     data  that is used.    ORD's  research  into  rate
                     constants and physical properties such as disper-
                     sivity,  hydraulic   conductivity,   and  effective
                     porosity  can therefore be  expected  to  continue.
                     Cost-effective  monitoring methods  will also  be
                     needed for early  detection of contamination from a
                     multitude of possible sources  before they can per-
                     colate into ground-water resources.

                          The success of ground-water remediation de-
                     pends largely upon understanding subsurface pro-
                     cesses. Some of the more important processes for
                     which research  is needed include   contaminant
                     multiphase behavior partitioning among  solid and
                     liquid media,  biotic and  abiotic transformations,
                     and transport in  fractured media. Predictive tools,
                     such as; models, will be needed to better account
                     for  these  processes.    Cost-effective monitoring
                     methods are also  needed  for detecting contami-
                     nants, characterizing site-specific subsurface condi-
                     tions, and tracking changes in ground-water quality
                     during remediation of contaminated ground water.
                     Improved knowledge of subsurface conditions will
                     also lead the way for  improvements  in  the design
                     of technologies for remediation, such as  innovative
                     ground-water pumping systems.  ORD efforts  to

-------
                                GROUND-WATER RESEARCH DESCRIPTION
                                            31
meet these prevention and remediation objectives
in the  future  will  continue  to be approached
through focused research projects in support of
EPA's programs, with  attention  to  coordination,
technology transfer, and technical  assistance.

-------

-------
                           GROUND-WATER RESEARCH DESCRIPTION
                                                                           33
           APPENDIX A. ORD GROUND-WATER RESEARCH BUDGET

    The following is a generalized table showing the distribution of ORD resources into major categories of
subsurface research.
                           ORD Ground-Water Budget History

ORD Activity
Subsurface
Modeling, Moni-
toring and Qual-
ity Assurance
Subsurface Pro-
cesses and
Effects
Subsurface
Engineering and
Technology
TOTALS
FY1990
FTE
22



79


5


106
S&E
1742



5789


409


7940
R&D
5744



8033


2114


15891
FY 1991
FTE
22



78


5


105
S&E
1757



6065


415


8237
R&D
4913



8474


1558


14945
FY 1992 (est.)
FTE
22



79


6


107
S&E
1667



6278


545


8490
R&D
5302



12585


1831


19718
KEY:
FTE
S&E
R&D
"Full-time equivalents" (one person per year)
"Salary and Equipment" monies (est. dollars in thousands)
"Research and Development" monies for contracts and grants
(est. dollars in thousands)

-------

-------
                            GROUND-WATER RESEARCH DESCRIPTION
                        35
                                    APPENDIX B.
  SUMMARY OF OUTPUTS FROM GROUND-WATER RESEARCH PROJECTS


   Appendix B presents the outputs of ORD's ground-water research program that are planned to be
   completed as a result of ground-water research conducted in FY91 and FY92. Some outputs are
   planned to be completed in FY93 and beyond (outyears) as a result of longer-term research projects.
                SITE CHARACTERIZATION AND MONITORING
                                                               FY91    FY92   Outvear
Develop and evaluate ground-water monitoring methods and strate-
gies for RCRA hazardous waste facilities. (PPA 115)

Ground-Water Monitoring (EMSL-LV)

   Project Report on Field Comparison of Ground-Water Sampling
   Methods

   Internal Report on Protocol for Testing Ground-Water Samplers

   Report on Comparison of Volatile Organic Compound Sampling and
   Surveillance Methods

   Guidance Document for Comparing Well Casing Material

   Complete Guidance Document Summarizing Screening Rules for
   Monitoring Wells

   Final Project Report on Quantitative Methods for Monitoring Net-
   work Design

   Project Report on Toolbox for Environmental Monitoring Using
   Ground-Water Models

   Final Guidance Document for Site Characterization and Contamina-
   tion Assessment

   Draft Guidance Document for Site Characterization and Contamina-
   tion Assessment

   Project Report on Temporal Variability (Arid) and Sampling Proce-
   dures for Ground water

Ground-Water Monitoring (EMSL-LV)

   Final Report on Bioremediation Monitoring ofBTEX

   Journal Article on  the Dielectric Tool for Laboratory Porosity  Mea-
   surements
10/90


11/90

 4/91


 8/91
         8/92


         8/92


         9/92
                 4/93


                 10/93


                 12/93
         5/92
                 12/92

-------
36
GROUND-WATER RESEARCH DESCRIPTION
       Appendix B. Summary of Outputs From Ground-Water Research Projects (Continued)
                                                                    FY91   FY92   Outyear
    Project Report on Surface/Surface to Borehole Geophysical Methods
 Develop Field Methods for Subsurface Monitoring (EMSL-LV)
    Project Report on Application of Borehole Geophysics to Waste Site    10/90
    Monitoring
 Molecular Fluorescence and Fiber-Optics Screening Methods (EMSL-
 LV)
    Development of Synchronous Luminescence Field Methods
    Report on In Situ Fiber-Optic Field Spectrometer (Luminoscope)
    Project Report on Portable Ultraviolet Fiber-Optic
    Spectrofluorometerfor In Situ Screening of Aromatic Compounds in
    Ground water
  Quality Assurance and Methods Standardization for Ground-Water
  Monitoring (EMSL-LV)
    Project Report on Technology Transfer and Hands-On Demonstra-
     tion
  Develop methods for  external leak detection at underground storage
  tank sites. (PPA R62)
  Characterization and Monitoring of Cleanup Around Storage Tanks
  (EMSL-LV)
     Report on In Situ Diffusion Coefficient Measurement Barrier Tests
     Report on Field Test of Peat for Adsorption of Hydrocarbon Con-
     taminants from Underground Storage Tanks
     Final Report on the BTEX Project for Analyzing Soil, Soil Gas
     (vapors), and Ground water
     Assessment Manual for In Situ  Biodegradation of Aromatic Hydro-
     carbons in Soil and Ground water
     Evaluation  of External Vapor Monitoring Sensors
  Provide monitoring techniques and procedures for Superfund site
  and situation assessments. (PPA  A04)
  Geophysical Methods (EMSL-LV)
     Project Report on the Evaluation of Selected Borehole Geophysical     10/90
     Methods for Hazardous Waste  Site Investigations and Monitoring
     Published Peer Reviewed Paper on Effect of Pipes on Transient        10/90
     Electromagnetic Soundings Used to Map Oil-Field Brine Contamina-
     tion
                                                        6/93
                                                       10/92
                                                       10/92
                                                       12/92
                                               6/92
                                       1/91
                                       8/91

                                       9/91
                                               9/92

                                               9/92

-------
                              GROUND-WATER RESEARCH DESCRIPTION
       37
       Appendix B. Summary of Outputs From Ground-Water Research Projects (Continued)
                                                                    FY91    FY92   Outyear
   Conference Paper on A New Instrument and Inversion Program for     10/90
   Near-Surface Mapping: High Frequency EM Sounding and Profiling
   ion the Frequency Range 300 KHz to 30 MHz

   PhD Thesis The Electrical Resistivity Method in Cased Boreholes,       5/91
   The University of California, Berkeley, CA

   Project Report on a Geophysics Expert System, Version 2.0             6/91

   Conference Paper on Seasonal Variations and Ground Penetrating               11/91
   Radar Repeatability

   Conference Paper on Novel Antenna Systems for Ground Penetrating             11/91
   Radar

   Conference Paper on Results of Integrated Surface Geophysical                 11/91
   Studies for Shallow Subsurface Fracture Detection at Three New
   Hampshire Sites

   Journal Article on Field Survey for Seismic Shear-Wave Source                 6/92
   Development

   Project Report on Field Case Studies of an Improved Ground Pene-
   trating Radar

   Journal Article on Ground Penetrating Radar Detection of Chlori-
   nated Solvents

Develop and evaluate new field-monitoring techniques and systems
that are rapid, inexpensive, and more sensitive. (PPA H03)

Advanced Field Monitoring Methods (EMSL-LV)

   Internal Report on a Geostatistical Report for Contouring and Spa-      11/90
   tial Interpolation of Hazardous Waste Data - A Case Study

   Internal Report on Field-Portable XRF Multi-Analyte Case Study        12/90

   Final Report on the Design of Chemical Coatings for Microsensors      12/90
   in  the'Detection and Analysis of Hazardous Materials

   Publication/Presentation of Extraction Disks and, Microporous Films     2/91
   for Spectroscopic Field Screening Applications

   Internal Report on a Comparison in In Situ Analysis Versus Sample      6/91
   Preparation and Homogenization Techniques for Laboratory XRF
   Analysis

   Internal Report on a Study  of Fundamental Parameters as a Stan-       9/91
   dardless Calibration Technique

   Adaptation of a Prototype Data Telemetry/Locator System to Porta-              1Q./91
   ble X-Ray Analyzer                •
10/92


 4/93

-------
38
GROUND-WATER RESEARCH DESCRIPTION
       Appendix B. Summary of Outputs From Ground-Water Research Projects (Continued)
                                                                    FY91    FY92   Outvear
 Vadose Zone Methods (EMSL-LV)
    Report on a Comparison of Volatile Organic Compound Sampling                        10/92
    and Surveillance Methods
    Draft Guidance Document for Site Characterization and Contamina-                      10/93
    tion Assessment
 Develop and evaluate advanced field monitoring methods for Super-
 fund sites. (PPA SOI)
 Advanced Field Monitoring Methods (EMSL-LV)
    Presentation on Spectroscopic Field Screening  Application              2/91
    Presentation on Extraction Disks and Microporous Films for Spec-       2/91
    troscopic Field Screening Methods for Hazardous Wastes and Toxic
    Chemicals
    Internal Report on Adaptation of Prototype Data Telemetry/Locator             10/91
    Systems to Portable X-Ray Analyzer
    Internal Report on Cone Penetrometer Evaluation                                       10/92
 Vadose Zone Field Methods for Site Screening and Assessment
 (EMSL-LV)
    Report on a Comparison of Volatile Organic Compound Sampling                        10/92
    and Surveillance Methods
    Draft Guidance Document for Site Characterization and Contamina-                      10/93
    tion Assessment
 Provide the scientific database and methods for the protection of
 ground-water resources. (PPA F81)
 Ground-Water Monitoring (EMSL-LV)
    Journal Article on Dupont Experiment Conducted to make Surface-      2/9 J
    to-Borehole Measurements  in Test Well Near a Class I Injection
    Facility in Tennessee
    Progress Report on Airborne Geophysical Surveys                     5/91
    Monitoring Strategies for Wellhead Protection Areas                           3/92
    Journal Article: Airborne Electromagnetic Surveys for Underground              3/92
    Injection Control
    Project Report on Seismic Noise Studies to Detect Contaminant                  7/92
    Migration
    Journal Paper on Seismic Methods for Fracture Delineation                              10/92

-------
                              GROUND-WATER RESEARCH DESCRIPTION
                 39
       Appendix B. Summary of Outputs From Ground-Water Research Projects (Continued)
                                                                  FY91    FY92   Outvear
                     TRANSPORT AND TRANSFORMATION
Provide field-evaluated methods and data to predict the concentra-
tions of wastes released from RCRA hazardous waste facilities.
(PPA C25)

Field Evaluation of Ground-Water Contamination Risks from Hazardous
Waste Disposal (Ada)

   Journal Article on an Eulerian-Lagrangian Localized Adjoint          12/90
   Method for the Advection-Diffusion Equation

   Paper on Hydrocarbon Spill Exposure Assessment Modeling            1/91

   Report on Nitrate Contamination Studies                             3/91

   Supply Manual for Multiphase Flow Code

   Report on Comparing Results of Artificial Aquifer with Model Pre-
   diction

   Report on Multiphase Chemical Transport in Porous Media

   Journal Article on Transport of Inorganic Solutes in Structured
   Media

   Report on QAIQC in Development and Evaluation of Ground-Water
   Models

   Research Brief on Numerical Model for Multiphase Chemical Trans-
   port Porous Media

   Journal Article on Transport of Organic Solutes in Structured Media

Prediction of Contaminant Behavior in the Subsurface (Ada)

   Journal Article on Cosolvent Effects on Sorption and Mobility of       11/90
   Organic Contaminants in Soils                         ,  •             ,

   Internal Report on Solute Transport in a Leaky Aquifer by Cubic        2/91
   Spline Collocation

   Report on Transport of Hydrophobic Organic Chemicals in Multi-       2/91
   Solvent Systems

   Report on Approximate Multiphase Flow Modeling by Characters-      3/91
   tics Methods

   Course on Use of Multiphase Chemical Transport Model               4/91

   User's Manual-MOFAT: A Two-Dimensional Finite Element Pro-        4/91
   gram for Multiphase Flow and Multicomponeht Transport
10/91

11/91


11/91

12/91


 1/92


 2/92


 7/92

-------
40
GROUND-WATER RESEARCH DESCRIPTION
        Appendix B. Summary of Outputs From Ground-Water Research Projects (Continued)
                                                                     FY91    FY92   Outvear
    Journal Article on the Influence of Organic Cosolvents on the Sorp-      5/91
    tlon Kinetics of Hydrophobic Organic Chemicals
    Internal Report on the Development of a New Technique for Deter-      6/91
    mining Total Organic Carbon in Contaminated Aquifer Materials

    Report on Comparisons of Two Dimensional Model Projections and      7/91
    Experimental Measurements of Multiphase Chemical Transport in
    Porous Media
    Paper entitled "Toward a Better Understanding of the Complex         7/91
    Geochemical Processes Governing Subsurface Contaminant Trans-
    port"
    Report  on Field Evaluation of Treatability Potential ofPCP and         8/91
    Creosote Wastes in Soil  .
    Journal Article on Comparing Simulated and Experimental Hyster-      8/91
     etic Two-Phase Transient Fluid Flow Phenomena
    Journal Article on Evaluation ofSorption Models in the Simulation      9/91
     of Naphthalene through Saturated Soils
    Journal Article on Effect of Ionic Strength on the Transport ofBac-      9/91
     teria in a Saturated Aquifer Material
     Internal Data Report on the Prediction of Contaminant Behavior in      9/91
     the Subsurface
     Journal Article on Transport in Time-Variant Mobile Phases

     Final Project Report on Laboratory and Modeling Study of Multi-
     phase Flow
     Computer Code for the Multiphase Flow Model (DNAPL)

     User's Guide for Dual Energy Gamma Ray Adsorption System
     Report on Investigation of Multiphase Wetting Behavior Using
     Capillary Pressure Data
     Research Brief on Spatial Heterogeneity of Biochemical and
     Hydrologic Parameters Affecting Metal Transport in Ground water

     Report on Three Dimensional Modeling of Subsurface Flow and
     Fate and Transport of Microbes and Chemicals
   Spatial Variability of Subsurface Properties and Processes (Ada)

     Research Brief on Methods for Handling  Spatial Variability on         12/90
     Subsurface Environments
     Report on Techniques to Determine Spatial Variations in Hydraulic      2/91
      Conductivity of Sand and Gravel
                                               11/91
                                                5/92
                                                         12/92

                                                          1/93
                                                          7/93


                                                          9/93

                                                         12/94

-------
                              GROUND-WATER RESEARCH DESCRIPTION	
      Appendix B. Summary of Outputs From Ground-Water Research Projects (Continued)
       41
                                                                    F.Y91    FY92   Outvear
   Journal Article on Large-Scale Natural-Gradient Tracer Test in         5/91
   Sand and Gravel, Cape Cod, Mass; 1. Experimental Design
   Observed Tracer Movement
   Book Chapter—Aseptic Sampling of Unconsolidated Heaving Soils in     7/91
   Saturated Zones
   User Friendly Computer Program for Estimating Hydraulic Proper-      9/91
   ties of Unsaturated Soils for Contaminant Transport Modeling
   Final Report on Fracture Characterization and Fluid Flow                      9/92
   Report on Electromagnetic Properties of Contaminated Soils
Corrective Action Technologies (Ada)
   Report on Properties Influencing Microbial Colonization of             2/91
   Hazardous Waste Sites
   Report on Forced Air Ventilation for Remediation of Unsaturated        3/91
   Soils Contaminated by Volatile Organic Contaminants
   User's Guide for the Mathematical Model LT3VS1 Denitriflcation on     3/91
   Nonhomogeneous Laboratory Scale 'Aquifers
   Internal Report on Full-Scale Treatment for TCE and Ground-Water     5/91
   Design Criteria and Economics
   Report on the Biotransformation of Monoaromatic Compounds Un-      8/91
   der Various Anaerobic Conditions
   Internal Report on Biodegradation ofPCBs in Complex Oily Wastes             12/91
   Final Report on a Recombinant Approach to the Isolation and Char-             1/92
   acterization of a Primary TCE Degrader
   Internal Report on Chlorobenzene Bioreactor Pilot Study                        3/92
   Journal Article on Experimental Procedures and Initial Results of                6/92
   Solvent Enhanced Desorption ofPCBs
   International Conference on SS Remediation                                   6/92
   Report on Chlorobenzene Bioreactor Pilot Study                               7/92
   Report on Feasibility Study for Bioremediation of                              7/92
   Trichloroethylene—Contaminant Soil
   Quantitative Description of TCE in an Aquifer                                 8/92
   Report on Hot Water Recovery of Light Waste Oils                             9/92
   Internal Report on the Role of Protozoa in Aquifer Biorestoration                9/92
12/92

-------
42
GROUND-WATER RESEARCH DESCRIPTION
        Appendix B. Summary of Outputs From Ground-Water Research Projects (Continued)
                                                                    FY91    FY92   Outvear
    Summary Report of Data Analysis for RCRA's Regulatory Impact
    Analysis
    Journal Article on the Impact of Solvents on the Rate ofPCB
    Desorption
 Provide integrated, multimedia methods and data to estimate poten-
 tial exposures to hazardous wastes from RCRA facilities. (PPA C28)

 Multimedia Modeling with Uncertainty Analysis  (Athens)

    Report on Results ofMINTEQAl Model Performance at Globe,
    Arizona Site
 Develop methods to predict subsurface contaminant concentrations
 to support risk analysis and source control. (PPA F83)

 Subsurface Physical/Chemical Processes Affecting Transport (Ada)

    Report on Sorption Properties of Soil and Aquifer Organic Matter

    Report  on Separation and Identification of Aquifer Organic Matter

    Journal Article on Transport of Inorganic Colloids in Undisturbed
    Subsurface Systems
    Report  on Facilitated Transport of Metal Contamination in the Sub-
    surface
    Article  on Transport of Organic Cations and Hydrophobic Organic
     Compounds in Laboratory Columns

    Internal Report on FT-IR Studies of the Sorption Properties of Soils
     and Aquifer Organic Matter

    Internal Report on Separation and Identification of Aquifer Organic
    Matter
     Article  on Evaluation of Multi-Site Modeling Approach for
     Predicting Contaminant Transport in Natural Subsurface Systems

     Report on Electromagnetic Properties of Contaminated Soils

     Report on Abiotic Reductions Between Haloaliphatic Chemicals and
     Environmental Reductants at Mineral Surfaces

     Report on Adsorption of Ionic Compounds on Natural
     Heterogeneous Materials
     Report on Characterization of Organic Matter in Soils and Aquifer
     Materials
                                               9/92
                                                        12/92
                                       6/91
                                      12/90

                                      12/90

                                       6/91


                                       6/91
                                              12/91


                                               6/92


                                               7/92


                                               9/92
                                                        12/92

                                                        10/93


                                                        10/93


                                                          1/95

-------
                              GROUND-WATER RESEARCH DESCRIPTION
                          43
       Appendix B. Summary of Outputs From Ground-Water Research Projects (Continued)
                                                                    FY91   FY92   Outvear
Prediction of Microbial Contaminant Concentrations (Ada)
   Report on the Swelling Properties of Soil Organic Matter and their
   Relation to Sorption of Non-ionic Organic Compounds
   Screening Model to Predict Virus Transport in Ground water
   Initiate Transport Modeling for Viruses
   Journal Article on Facilitated Transport of Metals in the Subsurface
Prediction of Biotransformation of Subsurface Contaminants (Ada)
   Report on Anaerobic Biotransformation of Contaminants in the Sub-
   surface
   Journal Article on Reductive Dechlorination
   Journal Article on Anaerobic Degradation
   Research Brief on Biodegradation of Pesticides in Aquifers
Evaluate models and management strategies in support of State
wellhead protection programs mandated by the Safe Drinking
Water Act Amendments of 1986. (PPA F89)
Develop Methods for Wellhead  Protection (Ada)
   Interim Report for the Application of Capacity Criteria to Wellhead
   Protection
   Final Report on Evaluation of Wellhead Protection Area Delineation
   Methods Including Use of the WHPA Codes in Ellis County, Kansas
   Report on Methods for Delineating Wellhead Protection Zones
   Around Springs
   Report on a Survey of Major Contaminant Impacting Public
   Drinking Water Wells
   Transport Modeling for Delineation of Wellhead Protection Zones: A
   consideration of Virus and Bacteria Transport
   Development of a Risk-Management Strategy for Wellhead
   Protection
   Final Report on Demonstration of the Analytic Element Method for
   Wellhead Protection
   Report on Development of a Risk-Management Strategy for Wellhead
   Protection
   Report on Delineation of Wellhead Protection Zones: Consideration
   of Virus Transport
 6/91

 9/91
         1/92
         9/92
10/90

 3/91
        12/91
         1/92
 1/91
         9/92

         9/92
                  12/92

                   8/93

                   8/93

                  10/93

                  10/93

                  12/93

-------
44
                             GROUND-WATER RESEARCH DESCRIPTION
       Appendix B. Summary of Outputs From Ground-Water Research Projects (Continued)
                                                                   FY91    FY92   Outvear
    Final Report on Validation of Models for Delineating Capture Zones
    in Wellhead Protection
 Determine how pesticides contaminate ground waters and remedial
 actions to alleviate the problem. (PPA D07)
 Validation of Predictive Techniques for Environmental Exposure
 (Athens)
    Report on Results ofMINTEQA2 model performance at Globe,
    Arizona Site
    Report on Literature-based Testing ofMINTEQA2
                                                                                    12/93
                                                                            1/92

                                                                            3/92
                         IN SITU AQUIFER REMEDIATION
Evaluate Technologies to Manage Uncontrolled Sites. (PPA B01)

In Situ Control Technologies (RREL)
   Report on Feasibility of Hydraulic Fracturing of Soil to Improve.         8/91
   Remedial Actions
   Paper on Prospects for In Situ Chemical Treatment of Contaminated            12/91
   Soils                                                                       -,,,.
   Pilot Test on Solid Oxygen Source for In Situ Bioremediation                    5/92
   Feasibility Study ofLeachate Recirculation for In Situ Treatment of              8/92
   MSW Landfills on the NPL

   Complete Field Tests of Hydrofracturing for Enhancing In Situ Re-
   medial Action
Evaluate abilities of natural and enhanced microorganisms for bio-
degradation of hazardous substances in Superfund remedial actions.
(PPA B02)
Enhanced Biorestoration of Contaminated Ground water (Ada)

   Report on Efficacy and Environmental Safety of Using Nitrate to        11/90
   Bioremediate Hazardous  Wastes

   Journal Article on Chemical Relationship Between Soil Gas, Core       6/91
   Material, and Water Quality at an Aviation Gasoline Plume Site

   Journal Article on Enhanced Biorestoration of Contaminated Ground    7/91
   water
   Report on Operation of the Pilot Scale Treatment System for TCE               10/91
   Biotreatment
                                                                                       9/93

-------
                              GROUND-WATER RESEARCH DESCRIPTION
                         45
      Appendix B. Summary of Outputs From Ground-Water Research Projects (Continued)
                                                                    FY91    FY92   Outvear
   Preliminary Report Listing the Computer Code and Documenting the
   Results of the Laboratory Studies Used to Calibrate the Model

   Article Comparing Results of the Batch Microcosm with the Column
   Study

   Report on Describing the Performance ofBioventing of Aviation
   Gasoline In Situ

   Report on Development and Calibration of a Model Describing In
   Situ Bioventing of Hydrocarbons from the Subsurface

   Internal Report on Evaluation of Denitrification for Biorestoration of
   JP-4 Jet Fuel-Contaminated Aquifer

   Final Report on Denitrification for Bioremediation of a Refinery
   Spill

Biodegradation Applications to Superfund Site Cleanups (Athens)

   Report on In Situ Biodegradation of Carbon Tetrachloride Under
   Denitrifying Conditions

   Report on the Use ofSulfate Reducing Organisms for Bioremedia-
   tion of Hazardous Waste Components

   Report on Co-Oxidation of PCBs During Metabolism of
   Polyaromatic Hydrocarbons

   Internal Report on In Situ Bioremediation of Chlorinated  Aliphatic
   Compounds by Toluene Oxygenase-Containing Bacteria
        11/91


        12/91


         9/92
                  10/92


                  12/92


                   8/93
11/90
11/90
                  10/92


                   9/93
                      UNDERGROUND SOURCE CONTROL
Develop methods to determine the fate of underground injected
wastes and develop safer technologies for underground injection
control. (PPA F88)

Methods of Determining the Mechanical Integrity of Injection Wells
(Ada)                                                      .,

   Report on Field Tested Methods for Part 2 of Mechanical Integrity
   of Injection Wells

   Report on Test Methods for Flow Behind Pipe from the Injection
   Well Mechanical Integrity Project

   Report on Potential for Invasion of Underground Sources of .
   Drinking Water Through Mud-Plugged Wells: An Experimental
   Appraisal
         2/92
                  10/92


                   9/94

-------
46
GROUND-WATER RESEARCH DESCRIPTION
       Appendix B. Summary of Outputs From Ground-Water Research Projects (Continued)
                                                                   FY91    FY92   Outvear
 Impact of Class I Wells on Subsurface Geological Materials (Ada)

    Report on Methodologies for Identifying Salinity Involved in Ground-     9/91
    Water Contamination
 Class V Injection Well Practices (Ada)

    Report on Methodology for Prioritizing Aquifer Sensitivity to Class V     9/91
    Wells
          TECHNOLOGY TRANSFER AND TECHNICAL ASSISTANCE
 Provide technical support on Superfund settlement agreements,
 especially to enforcement programs in Regions and states. (PPA
 F06)

 Geophysical Support (EMSL-LV)

    Funding for Geophysical Technical Support

 Provide Superfund enforcement and response programs with rapid
 access to the best available technical information, evidence, and
 testimony. (PPA F22)

 Clearinghouse for information on Ground-Water Remedial Action Tech-
 nologies (Ada)

    Workshop on DNAPL Site Characterization and Remediation
    Options

    Issue Paper on Remediation of Sites Contaminated with Trichloro-
    ethylene

    Issue Paper on Bioremediation of Contaminated Ground waters

    Issue Paper on Conducting Field Tests for Evaluation of Soil
    Vacuum Extraction

    Internal Report on GIS Application and Geostatistical Analysis of
    Hardema Co. Landfill-

    Issue Paper on In Situ Bioremediation of Vadose Zone Soils

    Report on Access to Subsurface Remediation Technology Database
     (STRD) by On-Line Bulletin Board System

     Report on Evaluation of Unsaturated/Vadose Zone Models for Super-
    fund Sites

     Report on Identification and Compilation of Unsaturated/Vadose
     Zone Models Possibly Applicable to Setting Soil Remediation Levels
     at Superfund Sites
                                     11/90
                                              1/92


                                              2/92


                                              2/92

                                              4/92


                                              5/92


                                              6/92

                                              9/92
                                                       10/92


                                                       11/92

-------
      	    GROUND-WATER RESEARCH DESCRIPTION	
       Appendix B. Summary of Outputs From Ground-Water Research Projects (Continued)
47
                                                                    FY91   FY92   Qutvear
   Summary Paper on In Situ Bioremediation of Chlorinated Solvents in                      11/92
   Contaminated Aquifers
Ground-Water Technical Support (Ada)
   Protocol for Evaluating Effectiveness of Ground-Water Remediation      1/91
   Activities at Superfund Sites
   Final Report on Determining Partition Coefficients for TCE on                 12/91
   Aquifer Material from the Main Street Superfund Site
   Report on Status of Available Ground-Water Models                             1/92
   Issue Paper on Basics of Ground-Water Modeling                              4/92
   Internal Report on the Characterization of Subsurface Contamination             6/92
   and Transport Potential to Ground water and at Chrome Plating
   Sites
   Report on Demonstration of Electromagnetic Borehole Flowmeter at             7/92
   three Superfund Sites
   Report on the Superfund Vadose Modeling Evaluation                          9/92
   Journal Article on Demonstrating Methods for Generating Input                          10/92
   Data for Modeling Pump-and-Treat Remedial Action
   User's Manual for the Application of the Electromagnetic Borehole                       10/92
   Flowmeter Techniques
Ground-Water Methods, Information Transfer & Applications
   Journal Article on Transport of Inorganic Colloids in Undisturbed       6/91
   Subsurface Systems
   Report on Facilitated Transport of Metal Contaminated in the Sub-      6/91
   surface: Part II - Colloidal Transport
   Issue Paper on Chemical Enhancements to Pump-and-Treat                     1/92
   Issue Paper on Behavior of Metals in the Soil Environment                      6/92
   Issue Paper on Fundamental and Principles of Soil Science as                   6/92
   Related to Contaminant Mobility in Soils
   State of the Art Document on Soil Venting                                     8/92

-------

-------
                               GROUND-WATER RESEARCH DESCRIPTION
           APPENDIX C. RECENT ORD GROUND-WATER PUBLICATIONS

     EPA publications in the 600 and 625 series (ORD) may be obtained by calling EPA's Center for
     Environmental Research Information at FTS 684-7562 (513-569-7562). Publications referenced by a
     PB number are also available from NTIS.  This list  encompasses both publications and journal
     articles.
49
 General

 ORD Ground-Water Research Plan: Strategy for 1991 and Beyond. EPA 600/9-90/042, September, 1990.

 Ground-Water Research Technical Assistance Directory.  EPA-600/9-91/006, March 1991.

 Protecting the Nation's Ground Water: EPA's Strategy for the 1990s-The Final Report of the EPA Ground-
 Water Task Force.  EPA 21Z-1020, July, 1991.


 Forum Issue Papers

 Ground-Water Sampling for Metals Analyses. EPA 540/4-89/001, March, 1989

 Accuracy of Depth to Water Measurements. EPA 540/4-89/002, August, 1989

 Soil Sampling and Analysis for Volatile Organic Compounds. EPA 540/4-91/001, February, 1991

 Characterizing Soils for Hazardous Waste Site Assessments. EPA 540/4-91/003, March, 1991

 Contaminant Transport in Fractured Media: Models for Decisions Makers. EPA/540/4-89/004, August, 1989

 Facilitated Transport. EPA 540/4-89/003, August, 1989

 Basic Concepts of Contaminant Sorption at Hazardous Waste Sites. EPA 540/4-90/053, October, 1990

 Dense Nonaqueous Phase Liquids. EPA/540/4-91/002, March, 1991

Performance Evaluations of Pump-and-Treat Remediations. EPA 540/4-89/005, October, 1989

Reductive Dehalogenation of Organic Contaminants in Soil and Ground Water. EPA 540/4-90/054, January,



 Site Characterization and Monitoring

 Sampling Frequency for Ground-Water Quality Monitoring. V.W. Lambou, EPA-600/X-86-081, 1986.

 Underground Storage Tank Monitoring: Observation Well Based Systems. R.A. Scheinfeld, J.B. Robertson,
 and T.G. Schwendeman,  Ground Water Monitoring Review, 6(4):49-55, Fall 1986.

The Effect of Sampling Frequency on Ground-Water Quality Characterization.  R. Rajagopal, Ground Water
Monitoring Review, 6(4):65-73, Fall 1986.

-------
50
GROUND-WATER RESEARCH DESCRIPTION
                 Appendix C. Recent ORD Ground-Water Publications (Continued)

Handbook: Ground Water.  EPA-625/6-87-016, March 1987.

Monitoring Well Installation, Purging, and Sampling Techniques—Part I:  Conceptualizations.  J.F. Keely and
Kwasi Boateng, Ground Water, 25(3):300-313, May-June 1987.

Monitoring Well Installation, Purging, and Sampling Techniques—Part II:  Case Histories.  J.F. Keely and
Kwasi Boateng, Ground Water, 25(4):427-439, July-August 1987.

Comparison of Complex Resistivity with Electromagnetic Induction. J.J. van Ee, EPA-600/X-03-044, 1987.

Expert System for Evaluating External Leak Detection Method for Underground Storage Tanks.  P. Durgin,
EPA-600/X-87-413, November 1987.

In Situ Monitoring at Superfund Sites with Fiber Optics—Part I: Rationale.  L.A. Eccles, SJ. Simon, and
S.M. Klainer, EPA-600/X-87-156, June 1987.

In Situ Monitoring at Superfund Sites with Fiber Optics—Part II:  Plan  for Development. L.A. Eccles and
SJ. Simon, EPA-600/X-87-415, November 1987.

Soil-Gas Measurement for Detection of Subsurface Organic Contamination.  H.B.  Kerfoot and L.J. Barrows,
EPA-600/2-87-027, PB  87-174884, April 1987.

Soil-Gas Sensing  for Detection and Mapping of Volatile Organics.  B. Eklund, R. Evans, D. Devitt, W. Jury,
T. Starks, and A.  Gholson, EPA-600-8-87-036, August 1987.

Gas Transfer Through Flexible Tubing  and its Effects on Ground-Water Sampling Results. T.R. Holm, O.K.
George, and J.J. Barcelona, EPA-600/J-88-145, PB 89-119374, 1988.
                                                                                  ,  : ' £ -!:": "
Oxygen Transfer  Through Flexible Tubing  and its Effects on Ground-Water Sampling Results.  T.R.  Holm,
O.K. George, and M.J.  Barcelona, EPA-600/J-88-145, 1988.

Geophysics Advisor Expert System.  G.R. Olhoeft, EPA-600/X-88-257, June 1988.

Network  Design  for External Release Monitoring  of Underground Storage Tanks.   K.  Stetzenbach,  EPA-
 600/X-88-143,  March 1988.

In Situ Monitoring with Fiber Optics, Part III: A Fiber Optic Chemical Sensor for Monitoring Gasoline. S.M.
 Klainer, D.K. Dandge,  K. Goswami, L.A. Eccles, and S.J. Simon, EPA-600/X-88-259, June 1988.

 Special Report on the Distribution of  Lead at the  Pepcon Site Using  X-Ray  Fluorescence for On-Site
 Screening, Henderson,  Nevada.  G.A. Raab, EPA-600/X-88-336, September 1988.

 Spatial Resolution of Ground-Water Contamination by Soil-Gas Measurement.  H.B. Kerfoot and M.J. Miah,
 Chemometrics  and Intelligent Laboratory Systems, 3(l-2):73-78, 1988.

 Soil-Gas Surveying Techniques, A New Way to Detect Volatile Organic Contaminants in the Subsurface. H.B.
 Kerfoot and D.L. Marrin, Environmental Science and Technology, 22(7):740-745, 1988.

 Soil-Gas and Geophysical Techniques for Detection of Subsurface Organic Contamination.  A. Pitchford, K.
 Scarborough, A.  Mazzella, EPA-600/4-88-019, May 1988.

-------
                                GROUND-WATER RESEARCH DESCRIPTION
51
                 Appendix C. Recent ORD Ground-Water Publications (Continued)

 Practical Guide to Aquifer Test Analysis.  M.S. Bedinger and I.E. Reed, EPA-600/X-88-261, June 1988.

 Modeling Vapor Phase Movement in Relation to UST Leak Detection—Phase I: Final Report.  R. Schreiber
 EPA-600/X-88-273, June 1988.

 Health and Safety Plan, Field Work and Sampling Plan,  and Site Screening  Report for  the Frontier Hard
 Chrome Site. R.K. Grant, EPA-600/X-88-272, June 1988.

 Generalized Ground-Water  Sampling Device Matrix.   K. Pohlman  and  J.W. Hess,  EPA-600/X-88-079,
 February 1988.

 Field Comparison of Ground-Water Sampling Methods—Interim Report. R.P. Blegen, J.W. Hess, F.L. Mffler,
 R.R. Kinnison, and J.E. Denne, EPA-600/X-88-260, June 1988.

 Evaluation of a Prototype X-Ray Fluorescence  System for Hazardous Waste Screening.   G.A. Raab, S.J.
 Simon, K.W. Brown, D. Cardenas, and L.A. Eccles, EPA-600/4-87-021, January 1988.

 Drilling and Constructing Monitoring Wells with Hollow-Stem Augers—Part 1:  Drilling Considerations and
 Part 2:  Monitoring Well Construction.  G. Hackett, Ground-Water Monitoring Review, 7(4) and 8(1), Fall
 1987 and Winter 1988.                                       :

 Development of a Field Portable X-Ray Fluorescence System for On-Site Hazardous Waste Screening.  G.A.
 Rabb, S.J. Simon, M.L. Faber,.and L.A. Eccles, EPA-600/X-88-262, June 1988.

 Comparison of Water Samples from PTFE,  PVC, and SS Monitoring Wells. MJ. Barcelona, G K George
 and M.R. Shock, EPA-600/X-88-091, February 1988.

 Development of a Capillary Wick Unsaturated Zone Pore Water Sampler. K.W. Brown, EPA-600/4-88-001
 January  1988.

 Survey Assessment of Field Techniques for Volatiles. D.W. Botrell, EPA-600/X-88-038, January 1988.

Proposed Guidance Document for External Monitoring of Underground Storage Tanks.   P Durgin  EPA-
 600/X-89-019, 1989.

Network Design Factors for Assessing Temporal Variability in Ground-Water Quality. M.J. Barcelona, D.P.
Lettenmaier, and M.R. Shock, Environmental Monitoring and Assessment, 12:149-179, 1989.

Draft  Standard  Guide for Sampling Ground-Water Monitoring Wells. ASTM Task  Group D.I8.21.07 on
Ground-Water Sample Collection, Handling, and Field Analysis, EPA-600/X-90-026, 1990.

Evaluation of Selected  Borehole  Geophysical Methods  for Hazardous  Waste Site Investigations  and
Monitoring.  K.  Tylor, J. Hess and S. Wheatcraft, EPA-600/4-90-029, 1990.

Field  Comparison of Ground-Water Sampling Devices for Hazardous  Waste Sites:   An  Evaluation Using
 Volatile Organic Compounds. K.F. Pohlman, R.P. Blegen and J.W. Hess, EPA 600/4-90-298, 1990.

Field-Portable X-Ray Fluorescence for Characterization of Hazardous  Waste Sites:  A Two Year Program
 Summary. G.A. Raab, (C.A. Kuheric, W.H. Cole III, R.E. Enwall,  and J.S. Dugan, EPA-600/4-90-009, 1990.

-------
52                             GROUND-WATER RESEARCH DESCRIPTION	

                 Appendix C. Re.cent ORD Ground-Water Publications (Continued)

Industry-Specific Ground-Water Contamination. J.K. Rosenfield, EPA-600/X-90-119, 1990.

Littleton, Massachusetts Wellhead Protection and Monitoring Strategy.  B. Moore, A. Cathcart and S. Danos,
EPA-600/M-90-009, 1990.

A Manual for Conducting Field Screening for Subsurface Gasoline Contamination.  G.A. Robbins, EPA-600-
8-90-067, 1990.

Nature and Hydrologic Significance of Fracture Trace, Lineaments,  and Fracture Zones Related to  Ground-
Water Monitoring.  R. Parizek, P. Lavin, R. Greenfield, R. Weiss, C. Shuman and M. Moran, EPA-600/X-90-
125, 1990.

Standard Guide for Vadose Zone Investigations Using the Downhole Neutron Probe.  ASTM Subcommittee
D18.21 on Ground-Water and Vadose Zone Investigations, EPA-600/X-90-017, 1990.


Transport and Transformation

Development of Land Disposal Decisions for Metals Using MINTEQ Sensitivity Analyses.  D.S. Brown, R.E.
Carlton and L.A. Mulkey, EPA-600/3-86-030, 1986.

Evolving Concepts of Subsurface Contaminant Transport. J.F. Keely, M.D. Piwoni, and J.T. Wilson, Journal
of the Water Pollution Control Federation,  58(5):349-357, May 1986.

Techniques for Delineating Subsurface Organic Contamination:  A  Case Study.  In, Detection, Control, and
Renovation of Contaminated Ground Water, American Society of Civil Engineers, April 1987.

Protecting Ground Water from  Viral Contamination by Soil Modification. R.B. Thurman and C.P. Gerba,
Journal of Environmental Science Health, A22(4):369-388, 1987.

CONTUR: An Algorithm for Two-Dimensional High Quality Contouring.  S.R. Yates, EPA-600/J-87-059, PB
 87-212957/AS, 1987.

Evaluating the Maintenance and Effects of Genetically Engineered Microorganisms. G.S. Sayler, C. Harris, C.
Pettigrew, et al., EPA-600/J-87-386, 1987.

 Macromolecules Facilitate the Transport of Trace Organics.  G. Bengtson, C. Enfield, and  R. Lindqvist, EPA-
 600/J-87-354, PB 88-220108, June 1987.

 Maintenance and Stability of Introduced  Genotypes  in Ground-Water  Aquifer Material.   R.K.  Jain,  G.S.
 Sayler, J.T. Wilson,  et al., EPA-600/J-87-136, PB 88-148192, May 1987.

 Modeling Microbial Fate in the Subsurface Environment. M.V. Yates  and S.R. Yates, EPA-600/J-88-022, PB
 88-219225, December 1987.

 DRASTIC:  A Standardized System for Evaluating Ground-Water Pollution Potential Using Hydrogeologic
 Settings. L. Aller, T. Bennett, J.H. Lehr,  et al., EPA-600/2-87-035, PB 87-213914/AS, May 1987.

 The Use of Models  in Managing Ground-Water  Protection Programs.  J.F. Keely, EPA-600/8-87-003, PB 87-
  166203, January 1987.

-------
                                GROUND-WATER RESEARCH DESCRIPTION
53
                  Appendix C. Recent ORD Ground-Water Publications (Continued)

MINTEQA1, an Equilibrium Metal Speciation Model: User's Manual.  D.S. Brown and J.D. Allison, EPA-
600/3-87-012, 1987.

Modeling the Impact of Conservation Tillage Practices on Pesticide Concentrations in Ground and Surface
Waters.  A.S. Donigian and R.F. Carsel, Environmental Toxicology and Chemistry, 6(4):241-250, 1987.

Processes Affecting Subsurface Transport of Leaking Underground Tank Fluids.  S. Tyler, M. Whitbeck, M.
Kirk, J. Hess, L. Everett, and S. Tyler, EPA-600/6-87-005, PB 87-201521, June 1987.

Anaerobic  Biotransformations of Pollutant Chemicals in  Aquifers.  J.M. Suflita, S,A. Gibson,  and R.E.
Beeman, EPA-600/J-88-142, PB 89-119341, May 1988.

Decay of Dissolved Substances by Second Order Reaction: Problem Description and Batch Reactor Solutions.
S.R. Yates  and C.G. Enfield. EPA 600/J-88-016, PB 88 219787, January 1988

Degradation of Halogenated Hydrocarbons.  J.T. Wilson, Biotec, Vol. 2, pp 75-77, 1988

Distribution and Activity of Microorganisms in Subsurface Sediments of a Pristine Study Site in Oklahoma,
R.M. Beloin, J.L. Sinclair, and W.C. Ghiorse, Microbial Ecology, 16(1):  85-97, July, 1988.

Factors Affecting Trace Metal Mobility in Subsurface Soils.   J.  Kotoby-Amacher and R.P. Gambrell, EPA-
600/2-88-036, PB 88-224829, June 1988.

Influence of Inorganic and Organic  Nutrients on Aerobic Biodegradation and on the Adaptation Response of
Subsurface  Microbial Communities. CM. Swindell, C.M. Aelion, and F.K. Pfaender, EPA-600/J-88-036, PB
88-225743, January 1988.

Interactive  Simulation of the Fate of Hazardous Chemicals During Land  Treatment of Oily Waste:   RITZ
User's Guide.  D. Nofziger, J. Williams, and T. Short, EPA-600/8-88-001, PB 88-195532, January 1988.

Macromolecular Transport of Hydrophobic  Contaminants  in Aqueous  Environments.  C.  Enfield and G.
Bengtsson,  EPA-600/J-88-008, February 1988.

Microbial Ecology  of the Terrestrial Subsurface. W.C. Ghiorse and J.T. Wilson, EPA-600/D-88-196, 1988.

Movement of Contaminants from Oily Wastes During Land Treatment.  T.E. Short, In:  Soils Contaminated by
Petroleum:  Environmental and Public Health Effects. E.J. Calabrese and P.T. Kostecki, Eds.,   New York,
John Wiley and Sons, pp. 317-330, 1988.

Organic Cation Effects on the Sorption of Metals and Neutral  Organic Compounds on Aquifer Material.  D.C.
Bouchard,  R.M. Powell, and D.C.  Clark, Journal of Environmental  Science and Health, A23(6):585-601,
August 1988.

Sorption Nonequittbrium During Solute Transport.  D.C. Bouchard, A.L. Wood, J.L. Campbell, et al, Journal
of Contaminant Hydrology, Vol. 2, pp. 209-223, July 1988.

Measurement of Hydrolysis Rate  Constants for Evaluation of Hazardous Waste Land  Disposal:  Volume 3.
J.J. Ellington, F.E.  Stancil, W.D. Payne, and C.D. Trusty, EPA-600/3-88-028, 1988.

-------
54
GROUND-WATER RESEARCH DESCRIPTION
                 Appendix C. Recent ORD Ground-Water Publications (Continued)

Microbial Ecology of the Subsurface at an Abandoned Creosote Waste Site.  J.M. Thomas, M.D. Lee, MJ.
Scott, and C.H. Ward, Journal of Industrial Microbiology, 4(2):109-120, March 1989.

Multiphase Flow and Transport in Porous Media, J.C. Parker, Review of Geophysics, 27(3): 311-328, 8-89.
EPA 600/J-89-548.

Risk of Unsaturated/Saturated Transport  and Transformation of Chemical Concentrations (RUSTIC). J.D.
Dean, K.A. Voos, and R.W. Schanz, EPA-600/3-89-048, 1989.

Agricultural Drainage Wells: Impact on Ground Water. R.D. Ludwig, R.L. Drake, and D.A. Sternitzke, EPA-
600/8-90-054, PB 90-252644, 1990.

Assessing the Geochemical Fate of Deep-Well Injected Hazardous Waste: A Reference Guide.  J.R. Boulding,
C. Grove, J. Thomhill, EPA-625/6-89-025a, 1990.

Colloidal Considerations in Ground-Water Sampling and Contaminant Transport Predictions.   R.W. Puls,
Nuclear Safety, 31(l):58-65, EPA-600/J-90-198, PB 91-116202, January-March, 1990.

Colloidal-Facilitated Transport of Inorganic Contaminants in Ground Water: Part I. Sampling Considerations,
R.W. Puls, R.M. Powell, and J.H. Eychaner. EPA 600/M-90-023.

Cosolvency of Partially Miscible Organic Solvents on the Solubility of Hydrophobic Organic Chemicals, R.
Pinal, P.S.C. Rao, and L.Lee, Environ. Sci. & Tech., 24(5): 639-647, 1990. EPA 600/J-90-201
                                                        * =-^%

Cosolvency and Sorption of Hydrophobic Organic Chemicals.  P.S.C. Roa, L.S. Lee, and R. Pinal,  Environ-
mental Science and Technology, 24(5):647-654. EPA-600/J-90-201, PB 91-116178, 1990.

Environmental Factors  Influencing Methanogenesis in a Shallow Anoxic Aquifer: A Field and Laboratory
Study. R.E. Beeman and J.M. Suflita, Industry and Institute Microbiology 5(l):45-57, EPA-600/J-90-007, PB
90-245515, January, 1990

Fate of PAH Compounds in Two Soil Types: Influence of Volatilization, Abiotic Loss, antf Biological Activity,
K.  Park, R. Sims, R. Dupont, W. Douchette, and J. Matthews, Environ. Tox. and Chem.,  9(2):  187-195,
February, 1990. EPA 600/2-90-026.

A General Mass-Conservation Numerical Solution for the Unsaturated Flow Equation,  M.A.  Celia, E.T.
Bouloutas and R.L. Zarva, American Geophysical Union, 26(7): 1482-1496, July 1990. EPA 600/J-90-445.

Ground-Water Transport of Hydrophobic Organic Compounds in the Presence of Dissolved Organic  Matter.
A.T.  Kan and M.B. Tomson, Environmental Toxicology and Chemistry 9(3):253-263, EPA-600/J-2-90-017,
PB 90-245291, March,  1990.

Laboratory Investigation of Residual Liquid Organics from Spills, Leaks, and the Disposal of Hazardous
Wastes in Ground Water.  J.L. Wilson, S.H. Conrad, W. Mason, W. Peplinski, and E. Hagan,  EPA-600/6-90-
 004, PB 90-23579, 1990.

Measurement of Hydraulic Conductivity Distribution: A Manual of Practice.  F.J. Molz, O. Guven, and J.G.
 Melville. EPA-600/8-90-046, 1990.

-------
 	GROUND-WATER RESEARCH DESCRIPTION                             55

                  Appendix C. Recent ORD Ground-Water Publications (Continued)

 Mobility and Degradation of Residues at Hazardous Waste Land Treatment Sites at Closure. R.C. Loehr, D.C.
 Erickson, L.A. Rogers, and D.M. Kelmar. EPA-600/2-90-018, PB 90-212564,  1990.

 Modeling Microbial Transport in Soil and Ground Water. M.V. Yates and S.R. Yates, American Society for
 Microbiology News 56(6): 324-327, EPA-600/J-90-216, PB  91-116160, 1990.

 A New Approach and Methodologies for Characterizing the  Hydrogeologic Properties of Aquifers. F.J. Molz,
 O. Guven, and J.G. Melville. EPA-600/2-90-002, PB 90-187063, 1990.

 Oasis: A Graphical Hypertext Decision  Support  System for  Ground-Water Contaminant Modeling.   CJ.
 Newell, P.B. Bedient, Ground Water 28(2):224-234, EPA-600/J-90-100, PB 90-245283, March-April, 1990.

 Acquisition and Analysis of Ground-Water I Aquifer Samples: Current Technology and the Trade Off Between
 Quality Assurance and Practical Considerations.   N.T. Loux, A.W. Garrison and C.R. Chafin, International
 Journal of Environmental  Analytical Chemistry. 38(2): 231-253, 1990.

 Effects of Cellular Aggregation on  the Ecology of Microorganisms.  D.L. Lewis and D.K. Gattie, ASM News
 56(5): 263-268, 1990.

 Solute Transport in Aggregated Media:  Aggregate Size Distribution and Mean Radii.  F.K.  Fong and L.A.
 Mulkey. Water Resources  Research. 26(6): 1291-1303, 1990a.

 Sorption Estimates for Modeling.  In: Pesticides in the Soil Environment. R.E. Green and S.W. Karickhoff,
 SSSA Book Series No. 2 and H.H.  Cheng. (Eds.).  Madison WI, Soil Science Society of America, 1990.


In Situ Aquifer Remediation
             -  v,»-
Underground Storage Tank Corrective Action Technologies.  EPA-625/6-87-015, January 1987.

A Field Evaluation of In Situ Biodegradation for Aquifer Restoration. L. Semprini, P. Roberts, G. Hopkins,
 and D. Mackay, EPA-600/2-87-096, PB 88-130257, November 1987.

In Situ Restoration Techniques  for  Aquifers Contaminated with Hazardous  Wastes.  M.D. Lee, J.T Wilson
and C.H. Ward. EPA-600/J-87-032, PB 87-198396, 1987.

Leaking Underground Storage Tanks:  Remediation with Emphasis  on In Situ Biorestoration.   J.M. Thomas,
M.D.  Lee, P.B. Bedient, et al., EPA-600/2-87-008, PB 87-168084, January 1987.

Opportunities for Bioreclamation of Aquifers Contaminated  with Petroleum Hydrocarbons.  JT  Wilson and
C.H. Ward. EPA-600/J-87-133,  PB  88-148150, 1987.

Biorestoration of Aquifers Contaminated with Organic Compounds.  M.D.  Lee, J.M. Thomas, R C Borden
P.B. Bedient, C.H. Ward,  and J.T. Wilson. EPA-600/J-88-078, 1988.

 Comparison of Methods to Determine Oxygen Demand for Bioremediation of a Fuel Contaminated Aquifer.
R.M.  Powell, R.W. Callaway, J.T.  Michaloski, S.A. Vandegrift, M.V. White,  D.H. Kampbell, B.E. Bledsoe,
 and J.T. Wilson, Journal of Analytical Chemistry, Vol. 34, pp. 253-263, 1988.

-------
56
              GROUND-WATER RESEARCH DESCRIPTION	

Appendix C. Recent ORD Ground-Water Publications (Continued)
Treatment Potential for 56 EPA-Listed Hazardous Chemicals in Soil. R.C. Sims, WJ. Doucette, J.E. McLean,
WJ. Grenney, and R.R. Dupont. EPA-600/6-88-001, PB 88-174446, February 1988.

Adaptation of Aquifer Microbial Communities to the Biodegradation ofXenobiotic Compounds:  Influence of
Substrate Concentration and Pre-Exposure.  C.M.  Aelion, D.C. Dobbins, and F.K. Pfaender, Environmental
Toxicity and Chemistry 8(l):75-86, January 1989.

Applications Analysis: SITE Demonstration Test, Terra Vac, Inc., EPA/540/5-89/003a, 1989

BIOPLUME II—Computer Model of Two-Dimensional Contaminant Transport Under the Influence  of
Oxygen-Limited Biodegradation in Ground Water.  H. Rifai, P. Bedient, J. Haasbeek, and R, Borden. EPA-
SW/DK-89-015, PB 89-151112, 1989.

In Situ Aquifer Restoration of Chlorinated Aliphatics by Methanotrophic Bacteria, P. Roberts, L. Semprini, G.
Hopkins, D. Grbic-Galic, P. McCarty, M. Reinhard. EPA  600/2-89-033, PB  89-219992. 1989

Technologies of Delivery or Recovery for the Remediation of Hazardous Waste Sites, EPA/600/S2-89/066,
1989

Technology Evaluation Report: SITE Program Demonstration Test, Terra Vac, Inc., EPA/540/5-89/003a, 1989

Treatability Potential for EPA-Listed Hazardous Wastes in Soil.  R.C. Loehr.  EPA-600/2-89-011, PB 89-
166581,1989.

State of Technology Review: Soil Vapor Extraction Systems, EPA/600/S2-89/024, 1989

Soil Vapor Extraction Technology Reference Handbook, EPA/540/2-91/003, 1989

Abiotic Reductive Dechlorination of Carbon Tetrachloride and Hexachloroethane by Environmental Reduc-
tants.  M. Reinhard, G.P. Curtis and M.R.  Criegman, EPA-600/2-90-040, PB 90-261553, 1990.

Approach to Bioremediation of Contaminated Soil.  J.L. Sims, R.C. Sims and J.E. Matthews.  Hazardous
 Waste and Hazardous Material, 7(2):117-149, EPA-600/J-90-203, PB 91-116152, 1990.

 Assessing Detoxification and Degradation of Wood Preserving and Petroleum Wastes in Contaminated Soil.
 W. April, R. Sims, and J. Sims. Waste Management and Research, 8(l):45-65, EPA-600/J-90-099, PB  90-
 245275, February, 1990.

 Assessing  Underground  Storage Tank Corrective Action Technologies: Site Assessment and  Selection of
 Unsaturated Zone Treatment Technologies, EPA/600/2-90/011, 1990

 Assessing Underground Storage Tank Corrective Action Technologies: Early Screening  of Cleanup Technolo-
 gies for the Unsaturated Zone, EPA/600/2-90/027, 1990.

 Basics of Pump-and-Treat Ground-Water Remediation Technology. J.N. Mercer, D.C.  Skipp, and D. Griffin.
 EPA-600/8-90-003, 1990.

 Chemical  Transport to Ground Water.  C.G. Enfield and S.R. Yates.  Pesticides in the Soil Environment:
 Processes, Impacts, and Modeling, No. 2 in SSSA Book Series, Ed. H.H. Cheng, Soil Society of America, pp.
 271-289, EPA-600/D-90-203, PB  91-137059, 1990.

-------
                                GROUND-WATER RESEARCH DESCRIPTION
57
                  Appendix C. Recent ORD Ground-Water Publications (Continued)

 Conducting Field Studies For Testing Pesticide Leaching Models, C.N. Smith, R.S. Parrisk, and D.S. Brown,
 International Journal of Environmental Analytical Chemistry 39(1), 3-21, 1990

 Denitrification of Nonhomogeneous Laboratory Scale Aquifers: 1. Preliminary Model for Transport and Fate
 of a Single Compound. F.T. Lindstrom and L. Boersma. EPA-600/2-90-009, PB 90-186305, 1990.

 Enhanced Bioremediation Utilizing Hydrogen Peroxide as  a Supplemental Source of Oxygen.  S  Ruling and
 B. Bledsoe. EPA-600/2-90-006, PB 90-183435, 1990.

 A Field Evaluation of In Situ Biodegradation of Chlorinated Ethenes: Part I, Methodology and Field Site
 Characterization, P.V. Roberts, G.D. Hopkins, D.M. McKay, and L. Semprini, Ground Water, 28(4):  591-604,
 July-August, 1990.  EPA 600/J-90-261, PB 91-144857

 Geostatistics for  Waste Management:  A User's Manual for  the Geopack (Version 1LO)  Geostatistical
 Software System. S.R. Yates and M.V. Yates, EPA-600/8-90-004, PB 90-186420, 1990.

 Handbook in In Situ Treatment of Hazardous Waste-Contaminated Soils, EPA/540/2-90/002, 1990

 Innovative Processes for Reclamation of Contaminated Subsurface Environments.  L.W. Canter, L.E.  Streebin,
 M.C. Arquiaga, F.E. Carranza, and B.H. Wilson, EPA-600/2-90-017, PB 90-199514, 1990.

 A  Method for Testing Whether Model Predictions Fall Within a Prescribed Factor of True Values, With an
 Application to Pesticide Leaching, Ecological Modeling, 51, pp. 59-72. 1990

 Oasis: Parameter Estimation System for Aquifer Restoration Models, User's Manual Version 2.0.  CJ. Newell,
 J.F. Haasbeek, L.P. Hopkins, S.E. Alder-Schaller, H.S.  Rifai, and P.B. Bedient, EPA-600/8-90-039 PB 90-
 181314, 1990.

 Reliability and Applicability of DSTs and Bottomhole Pressure Measurements in Texas Gulf Coast Tertiary
 Formations.  M.S. Akhter and C.W. Kreitler, Journal of Petroleum Science and Engineering 3(4V287-303
 EPA-600/J-90-102 PB 90-245309, January, 1990

The  Superfund  Innovative  Technology Evaluation Program:  Technology  Profiles,  EPA/540/5-90/006,
November,  1990

Total Organic  Carbon  Determinations in Natural and Contaminated Aquifer Materials,  Relevance,  and
Measurement.  R.M. Powell. Ground-Water Management 2:1245-1245. EPA-600/D-90-159 PB 91-129205
 1990.

Use of Models for Granting  Variances from Mandatory Disinfection of Ground Water used as a Public Water
Supply.  M.V. Yates. EPA-600/2-90-010, PB 90-186347, 1990.
 Available Models for Estimating Emissions Resulting from Bioremediation: A Review.  S. Sharp-Hansen
EPA/600/3-90/031, 1990.

 Database Analyzer and Parameter Estimator (DBAPE)  Interactive Computer  Program User's Manual  J C
 Imhoff, R.F. Carsel, J.L Kittle, Jr., P.R. Hummel. EPA /600-89/083.

 Degradation Kinetics of Chlorinated  Aromatic Compounds in  Saturated Subsurface Environments    JE
Rogers, J. Struijs, D.D. Hale and P.O.  Bryant.  EPA/600/M-90/003, 1990.

-------
58
GROUND-WATER RESEARCH DESCRIPTION
                 Appendix C. Recent ORD Ground-Water Publications (Continued)

Anaerobic Biotransformation of Contaminants in the Subsurface, J.M.  Suflita and G.W. Sewell, February
1991. EPA 600/M-90-024.                                             .                           ,

Approximate Multiphase Flow Modeling by Characteristic Methods, J.W. Weaver. EPA 600/2-91-015.

Bioconcentration Factors and Lipid Solubility. S. Banerjee and G.L. Baughman, Environmental Science and
Technology. 25(3): 536-539, 1991.

Biodegradation of Aromatic Hydrocarbons by Aquifer Microorganisms Under Denitrifying Conditions, S.R.
Hutchins, and D.A. Kovacs, Environ. Sci. Technol., 25(1): 68-76,  January 1991.  EPA 600/J-91-084.

Biodegradation of Hydrocarbon Vapors in the Unsaturated Zone,  D.W. Ostendorf and D.H. Kampbell, Water
Resources Research, 17(4): 453-462, April  1991. EPA 600/J-91-084.

Environmental Factors Affecting Toluene Degradation in Ground Water as a Hazardous Waste Site.  A.Q.
Armstrong, R.E. Hodson, H-M.  Hwang and D.L.  Lewis. Environmental Toxicology and Chemistry. 10(2): 147-
158, 1991.

Facilitated Transport of Inorganic  Contaminants in Ground Water: Part II. Colloidal Transport, R.W. Puls,
R.M. Powell, D.A. Clark and CJ. Paul, July, 1991. EPA 600/M-91-040.

Feasibility of Hydraulic Fracturing of Soil to Improve Remedial Actions, EPA/600/S2-91/012, 1991.
 Forced Air Ventilation for Remediation of Unsaturated of Unsafurated Soils Contaminated by VOC, J.S. Cho.
 EPA 600/2-91-016.

 MINTEQA2/PRODEFA2, A Geochemical Assessment Model for Environmental Systems: Version 3.0 User's
 Manual, J.Allison, D.S. Brown, and K.J. Novogradac. EPA 600/3-91-021, March, 1991.

 Modeling Multiphase Organic Chemical Transport in Soils and Ground Water, J.C. Parker, A.K. Katyal, J.J.
 Kaluarachchi, R.J. Lenhard, T.J. Johnson, K. Jayaraman, K. Unlu, J.L Zhu. EPA 600/2-91-042

 Movement of Bacteria Through Soil  and  Aquifer  Sand, M. Alexander, R.J.  Wagenet, P.C.  Baveye, J.T.
 Gannon, U. Mingelgrin, Y. Tan. EPA 600/2-91-010

 Remediation of Sites Contaminated with TCE, H.R. Russell, J.E. Matthews, and G. Sewell, Remediation: 167-
 183, Winter 1990-91. EPA 600/J-91-030

 Solubility, Sorption, and Transport of Hydrophobic Organic Chemicals in Complex Mixtures, P.S.C. Rao, L.S.
 Lee, and A.L. Wood. EPA 600/M-91-009

 Stimulation of the Reductive Dechlorination of Tetrachloroethane in Anaerobic Aquifer Microcosms by the
 Addition of Toluene, G.W. Sewell and S.A. Gibson, Environ. Sci. & Tech. 25(5): 982-984, 1991. EPA 600/J-
 91-111
 The Swelling  Properties of  Soil Organic Matter  and  Their Relation to Sorption of Non-Ionic  Organic
 Compounds, W.G. Lyon and D.E. Rhodes. EPA-600/2-91-033, PB 91-217406

 Techniques to Determine Spatial Variations in Hydraulic Conductivity of Sand and Gravel, K.M. Hess and
 S.H. Wolf. EPA 600/2-91-006.

-------
     	GROUND-WATER RESEARCH DESCRIPTION	                 59

                      Appendix C. Recent ORD' Ground-Water Publications (Continued)

     Underground Source Control


     Injection of Hazardous Waste Into Deep Wells.  A.  Strycker and A.G. Collins, EPA-600/8-87-013 PB 87-
     170551, February 1987.                                                                    '


     Injection Well Mechanical Integrity. J. Thomhill and B. Benefield, EPA-625/9-89-007, September 1989.

     Hydrologic-Hydrochemical Characterization of Texas Gulf Coast Saline Formations Used for Deep-Well Injec-
     tion of Chemical Wastes. C.W. Kreitter, M.S. Akhter, and C.A. Donnelly, EPA-600/2-88-046, PB 88-242573
     1988.


     Laboratory Protocol for Determining Fate of Waste Disposed in Deep Wells. A.  Collins and M Crocker
     EPA-600/8-88-008, February 1988.


     Assessing the Geochemical Fate of Deep-Well Injected Hazardous Wastes:  Summaries of Recent Research.
     J.R. Boulding, C. Grove, J. Thornhill, EPA-625/6-89-025b, 1990.


     A Feasibility Study of the Effectiveness of Drilling  Mud  as a Plugging Agent in  Abandoned Well.  M.D.
     Smith, R.L. Perry, G.F. Stewart, W.A. Holloway, and F.R. Jones, EPA-600/2-90-022, PB 90-227232, 1990.



     Surface Source Control


     Leak Prevention in Underground Storage Tanks: A State of the Art Survey, EPA/600/2-87/018, 1987

     Design, Construction, and Evaluation of Clay Liners for Waste Management Facilities, L J. Goldman et  al
     EPA/530/SW-86/007F, November 1988

     Lining of Waste Containment and  Other Impoundment Facilities, Matrecon Inc., EPA/600/2-88/052 Septem-
     ber, 1989


     Chemicals  Stored  in Underground Storage Tanks: Characteristics and Leak Detection,  EPA/600/2-91/037,
U.S. GOVERNMENT PRINTING OFFICE: 1992-648-003/40718

-------

-------

-------

-------
  .',*•''• ';-_•'— \/.>. 'A" -~- "•-'•r'"*  ^: "";•,/•••• '•'•-^•..'.f'-'  v.1-": '^'--^^ -~\ •',./-• ^'^.C  • ''""•— ^-^kr~-'  Sv." L~   ~''--, ^C -'"t""-^:^  '"O-.'• -~,,'•""""••-• ..:'';



  "*  ''        :    "'"      '  "'•'•--•'    "x   •   ••"'•  "•"•    "•    '  '•"•••  '^^";•-..:'•'.-...'  '^'^";:--r'»^-ir---^-;.r-> 'ti^-'T •-"':'-"-'4 Xti;-^••:~.<=-
                                                                          '"^'"jT'"''"''>'  >;?';.:  "^  ;   -v'iltM.'.^"'"";^ , •%        .  ^-^ --" '



                                                                           7.-•'--'""~ ^'"'^ ^-^i:-..ri'-"c'-S:L:"--r-'" '.,"~d;"-^'7" --„:" •"'•'""T^ Vs

                                                                          ::.x>!v.^ ;'•••  - *c-- '^N: ^'""' /l"^—^:"::" '^^?:"":^::'^-''-i?
                         	       ,   .. , ,     ,.,-    ,       ,    „,  --'-'~^,^ '"*•-•! fA,-i'."-51J1:>^1C-'¥-^> ^ :'''- ''i ' --^ ^":' '—5   •*" "  '->
                      ,  .  -'-.-,  --•-,-  ~  :.^A-rN-^   '-^-'C.- Y.vf  W-; =».  -"- • -.<•-•. ->- ;•"•-,-.,  ^'.--^'      ^;? i'^.-.-.i-x^-.'i.i.'i.^rr •";->_; •..-.  - , '-
                     L  ^ . .' "' •'..'•:>- ' "'^- ".: ",- "''iV-^-'T'1  - -*"• '"^ ' ' ""--«.-  >'''^.". "•• ^'^-^'^ " -  \!'^;'  -F-i!"t^-^'\ >1 v .' : .V~   '-;-•' !j -1 .' '-••$'•>: .
                      *• •  V^.'  .  '•'-•   ~"  '~-^~ff- "'1'^-1*-'',  ~f "*,•'*'^ •' ^: ' ~ '-"''  .'''"•''?*  - ""'' '*  -'?-'" —;   ' ,-="<:t ^--r'J ',".,; -.v-- v - -£-. ,-»-•'- <"; —•
                     ',.::-'>-.^ ._- ;,~/.A-.:?;:;^-.'v^^  'c:^..'  f-^'^r..-'^. £  .:.-}''-'•" -r-^v.  '-  ^X^^T:^^;^'-"^." o-%_.-r^"1 -;
                                      "X-  ,	    .   ..        __



                                                      ••'15-. \: ';• •'
                                            i- _^. ~-i
                            '                '
 -•  ...  "" V'- :/V<"."K"^V-  -.^.&~h*3?tt^....
    ' •,    -    • ^'". /• •*- :^- ^ ^,_ ; _^>'s,'4s .*|,^-,;j-,. ,-%,'i-; JWi j^,- •-Vv,,,,;/'^ ;^-^ „•  ^ ?i ;. -, ^-'•r • j=j ^T"i ', x,**^'" ^'-* '.^'/X-T^^-^'v ^ ^


 "-   •''-  .-•'•••    •"' '-:^'^;";7- '•-'• T"-,.~J:'"f,''r'V"- ;rl^:7-'"'.">;'-;"^'%f"  ' ^-^-^r'^^r."
 .  -,-,    •™  - ',     '  :^^ •-.,.•  . >^ •;,'.'> M-*--,. ...  -"\"-  -><•_-•-...  • 'i-~  •'.•'.r-  ".,.*: T-:   i -' *'•
../^  *"" • '^-!••''- v,-'.  •  x-'••; ^j "v1 ,"••• .''.".y^'^-''^."-^-^"  •',.> -u1 -  •—^  ,,>"^,    .- -5=.,.'f-:..1,:-  -

   y'7' ":< ''S-.^'--   •*•"- '•:' ;^T';-^>".''4'"-:^;^; \v'v:>' ?i^b:"?'"';'" > ~'^-^-"  >-^ie"; -
                                                                             :'Ui

                                                                                                  .             -       .,,..,  -   ,     s-  _-..,



                                                                                       '•^^'^^•^•-•^^^^"'••''•.'•^ ''^••'^•••'*^:^2^i''\^~




''•'..   - ~~.'~-\-5 :;-. :"'.•''•• ^.'/'Vv- :'"

.,  .  '  • ,,'  • '  "v*-   ,'.'''  "^ ^ -^/''  ^- V  .• '-•* '.''."" i'^'-**,'-"' 'V-- -, "^  -S-'":'''  ^ '' •'-- '^--^ *  ^" '"*'•;"• -.^   '-'ft-^— ^ '  -•'"'•'  ' •• >~'~~~'"~~~' -' •-""~*^r -''
     •         '                           '                       "         "   "                       ~'                "      ''               "
                                                     ..    -



                                                ' .-'^-.^ !;--rt.-'' ^"''S'^ '-' '



-------