United States
                  Environmental Protection
                  Agency
Robert S. Kerr
Environmental Research Laboratory
Ada OK 74820
                  Research and Development
 EPA/600/S8-90/039  May 1990
&EPA         Project  Summary
                   OASIS:  Parameter  Estimation
                   System  for Aquifer Restoration
                   Models-User's  Manual
                   Version 2.0
                  Charles J. Newell, John F. Haasbeek, toren P. Hopkins, Sarah E. Alder-
                  Schaller, Hanadi S. Rifai, Philip B. Bedient, and G. Anthony Gorry
                  OASIS, a decision support system for
                  ground-water contaminant modeling,
                  was designed to provide a set  of
                  tools to help scientists and modelers
                  assess ground-water  contamination
                  problems. OASIS  was developed
                  around BIOPLUME II, a  numerical
                  model  that simulates the  aerobic
                  degradation   of   dissolved
                  hydrocarbons in ground water. The
                  system was developed  in the
                  HyperCard* environment and contains
                  extensive  documentation  and
                  onscreen help. Question mark icons
                  throughout lead  the user to further
                  discussion and definitions,  thereby
                  allowing  the  system to  be fully
                  operational without the aid of paper
                  documentation. The  information  in
                  OASIS  includes documentation, a
                  hydrogeologic  database,  two
                  chemical databases, several  simple
                  hydrogeologic  models, and the
                  BIOPLUME   II   model   with
                  preprocessors and  postprocessors.
                  The system was developed for use
                  on  Macintosh* personal computers
                  and now contains over 1600 screens
                  and 9 megabytes (Mb) of information.
                  The installation of  the software
                  requires 10 Mb of disk  space.
                   This Project Summary was
                  developed  by  EPA's R.  S. Kerr
                  Environmental Research Laboratory,
                  Ada, OK, to announce  key findings  of
                  the research project that  Is fully
                  documented in a separate report  of
                  the same title (see Project  Report
                  ordering information at back).
Introduction
  OASIS  has been developed  for the
EPA  by  Rice University, through the
National  Center  for Ground Water
Research. As a decision support system,
OASIS was designed to provide scientists
and modelers with a collection of tools to
help assess and analyze ground-water
contamination problems. New types of
software are being developed for
problems that have traditionally  been
difficult to implement using conventional
computer technology.  Decision  Support
Systems (DSS) help the user to deal with
broad problems that do not have a clearly
defined solution procedure. The use of a
ground-water contaminant  transport
model is a semi-structured problem that
requires the scientist to make a series of
decisions related to representation of the
site, application  of available  data, and
types of simulations to be performed.

HyperCard
  OASIS was built using HyperCard, a
software package provided with the Apple
Macintosh.  In   the  HyperCard
environment,  each different  screen of
information is called a "card," and cards
are collected into groups called "stacks."
The cards within a stack are connected to
each other by "links." These links may
take many forms.  For example, a link
may consist of a "button" which sends
the user to a particular card  or a "field"
 "HyperCard and Macintosh are trademarks of
 Apple Computer, Inc,

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which displays data  taken from another
card.  In HyperCard,  fields  and buttons
link together cards, stacks, and other files
and programs in the  computer. The user
is able to navigate through large amounts
of  information using  a series of  mouse
clicks on active buttons. Thus, instead of
going screen by  screen through  the
computer (or similarly page by  page in a
book), a user is allowed nonsequential
access to information in the system. The
first card  in  the  OASIS system  (the
OASIS Home card)  contains an Intro
button which gives   more  information
about HyperCard.  The user is  also
referred  to the HyperCard user's manual
for any additional questions.

OASIS System Contents
  The  OASIS  system consists  of
documentation,  a  hydrogeologic
database, two  chemical  databases,
several  simple  hydrogeologic models,
and  the BIOPLUME  II  model with
preprocessors and postprocessors.
  Each card in  OASIS  consists  of one
screen  of  information  on a picture
background.  Cards are organized into
stacks of related information, with most
cards  in  a stack  having similar
backgrounds.  Several  different
backgrounds  are  used in  the  OASIS
system.  These backgrounds include
pictures  of  tab cards, open  books,
notebooks, etc. Text in a card is entered
into a text field.  Text fields take many
different forms: rectangular, opaque (on a
white  background),  shadowed,
transparent  (only the  text can  be seen,
not the field) or scrolling. Buttons connect
information  within the  OASIS system,
thereby  providing  links between  cards.
Clicking  on a button takes the user to
another card  within  the  system  or
performs some operation on data entered
in a field. In the OASIS system, there is a
convention for each of the button styles
used.

Notebook
  The  notebook  is  a system  within
OASIS that allows the  user to transfer
information  between  stacks or from the
support system to  the  models.  For
example, parameter  data can  be taken
from  the  chemical  or  hydrogeologic
stacks and put into the notebook for later
use in the preprocessor.
  Portions  of the hydrogeologic and
chemical databases also contain a button
called Notebook. Clicking the  Notebook
button will automatically enter  data from
the card into the notebook and then open
the notebook.
Reference Library
  The reference stack  contains  libraries
of information related to ground water.
Clicking on  any of the terms  in  the
flowchart takes the  user to contaminant
information related  to that  source.  The
reference stack also contains information
on source by zone,  a glossary of terms,
the Rokey  database  which provides
discussion of parameters used in ground-
water modeling, and  a  Remediation
stack. The Remediation stack contains
information  on  different  remediation
techniques  for  contaminated ground-
water  aquifers  and  also  presents
BIOPLUME  II   simulations,   which
demonstrate  the  importance  of  well
placement and source term definition.

Hydrogeologic Database
  The  hydrogeologic  database  was
developed to take advantage of the many
hydrogeologic investigations  that have
been conducted  at waste sites but have
not been  reported in the  technical
literature. An extensive technical survey
of ground-water professionals  was
conducted  with  funding from   the
American  Petroleum  Institute  and
assistance from the National Water  Well
Association.  Data from 400  field  sites
across  the country  were obtained  from
ground-water   professionals  and
incorporated into a database.
  The database was structured using the
concept  of  hydrogeologic settings
developed  for  the EPA's  DRASTIC
system, an aquifer  vulnerability index
using  hydrogeologic  settings.  The
database  is  used by  determining  the
hydrogeologic setting that  best matches
a  site or an  area of interest.  The
hydrogeologic setting  is  selected by
determining  the  ground-water  region,
aquifer media, and then the  setting which
best describes the site  in question.  The
setting is used to access  the database;
the database statistics can then  be  used
for ground-water modeling  or for general
site characterization  purposes.

General Chemical Database
  The  general  chemical  database
contains 117 chemicals with one card of
information per chemical and was taken
from the ROKEY  database. Chemical
information can  be accessed  in  four
ways: by category,  by name, by  EPA
number, or by CAS number (Chemical
Abstract Service  number).  The  general
chemical database  contains a Notebook
button  which enters data from the  card
into the notebook (for  more information
on the notebook  see  the previous
discussion).
Specific Chemical Database
  The  specific chemical  databas
contains 18 chemicals with 25  cards  (
information per  chemical.  The first car
of the database has buttons which acces
information  related  to  Identificatior
Physical  Properties, Fire  Hazard Date
Chemical  Reactions, and Toxicology
These  terms  are  defined as they  an
used to describe  the chemicals  in  thi
database.

Darcy's Law
  The  Darcy's law stack  calculates th<
ground-water velocity  in a system when
hydraulic  conductivity,  gradient,  am
porosity  are  known. The help  buttoi
(question mark icon) gives information fo
each of the parameters needed  in tht
calculation.

Analytical Models
  Currently, only one  analytical  model is
contained in this stack. ODAST is a one-
dimensional solute  transport  model  thai
considers  advection,  dispersion,  solute
decay,  source decay, and  adsorption,
Output  from the model is provided as a
two-way  table  of  dimensionless
concentration  versus time and  distance.
The  ODAST model is a  useful tool for
providing preliminary estimates  of solute
transport in a ground-water system.

BIOPLUME II Model
  BIOPLUME II is  a two-dimensional
computer model  that  simulates  the
transport  of  dissolved  hydrocarbons
under  the influence  of  oxygen-limited
biodegradation.  BIOPLUME  II also
simulates  reaeration  and   anaerobic
biodegradation as a first-order  decay in
hydrocarbon concentrations.  The model
is based on the USGS solute  transport
two-dimensional code. It  computes  the
changes in concentration  over time  due
to advection,  dispersion, mixing,  and
biodegradation.  BIOPLUME II solves the
solute  transport equation twice: once for
hydrocarbon and once for oxygen. As a
result, two plumes are computed at every
time step.   The model assumes an
instantaneous reaction between oxygen
and   hydrocarbon  to   simulate
biodegradation  processes.  The  two
plumes are combined using the principle
of superposition.
  The model is extremely versatile in that
it can  be used to simulate natural
biodegradation  processes, retarded
plumes,  and  in-situ   biorestoration
schemes.  BIOPLUME II allows injection
wells to be specified  as oxygen sources^
into  a contaminated  aquifer,  and  the

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 model can be used to evaluate alternate
 Ttethods  for aquifer  reclamation.  A
 graphical   preprocessor  for  the
 BIOPLUME II model has been developed
 to facilitate data entry.

 OASIS Example
   As  an example of the way in which
 OASIS can be used as a support tool for
 the  BIOPLUME  II model,  consider a
 gasoline leak at a service station located
 in the western  mountain ranges.  The
 following steps might occur  when using
 the system.
   First, the user might consult one of the
 two chemical databases  contained  in
 OASIS. The user could  refer  to  the
 specific chemical  database to examine
 physical data on  benzene (Figure  1). If
 the  user  is  unfamiliar   with  the
 hydrogeology of the area, he or she can
 enter  the  hydrogeologic  database.   The
 correct ground water  region  is  selected
 first, then the aquifer media, and then the
 hydrogeologic setting,  as  pictured  in
 Figure 2. Once the setting is known, the
 user can examine  data from sites with a
 similar  hydrogeologic  setting.   The
 hydrogeologic data is  designed to be
 used as a general educational tool  and
 not as a substitute for field work.
   At  this  point, the  user  can  run  the
 inalytical  model   to help set  up  the
 problem  or  enter directly into  the
 BIOPLUME  II   preprocessor.  The
 preprocessor  was  designed  to do three
 things: structure the data  entry process,
 give immediate* access  to ground water
 and  data  entry  help,   and  provide  a
 graphical  method for  entering   and
 viewing  the spatial information used by
 the model.
  Once  the  user  finishes entering  the
 data,  the preprocessor makes a text file
 corresponding to the format required by
 BIOPLUME II. The model  is run and the
 graphical  postprocessor,  BioGraph,
 displays  the  output from  the  model
 (contaminant  concentrations  over  the
 area  of the  aquifer) in  the  form  of
 patterns. Darker patterns correspond to
 higher concentrations.  The development^
of  the plume over  time can be seen witlf
an  animation  option  in  BioGraph.
Concentration profiles over time or over
distance can be  examined  also.  The
preprocessor and  the postprocessor for
BIOPLUME II  were designed to facilitate
model calibration and data evaluation.
Physical data
Physic*! State
Melting Point
Boiling Point
Specific Gravity
Tapor Pressure
Vapor Density
Solubility in Water
Solubility in Coa*on
    Organic Solvents
Fire Hazard Data
                        liquid
                        3.3 - 6"C
                        80°C
                        0.88
                        73-76 MM Kg «t 20°C
                        2.7 - 2.8
                        0.07 - 0 19 wt *
                        •»lc,CS2,»th,»c »,
                        a.ce,CHC13,and CC14
                                                          Benzene
              2,3,6,7,206
              1,2,3,4,206
              2,3,4,6,8,206
              1,14,200,206
              6,8,10,14,200
              3,186,187,203,206,210,226
              2,4,6,7
Flash Point - Open Cup 21 *t
Closed Cup 12°F
Autoignition Temperature 1000T - 1076'F
Flawaability Units in Air (* by vol)
Lover 1 3
14
3,3,6,8,10,48,206
3,5,6,7,8,10,13,206
8,13,14,207
T
2
      ID info
                 Properties ss
Reactions H| Toxicology
                             Modeling

                            I References I
 Figure 1. Card from the specific chemical database, benzene.
    Setting:  GLACIATED MOUNTAIN
                VALLEYS

   This jetting is characterized by moderate
   topographic relief and very coarse grimed
   deposits associated with the near mountain
   glacial features such as cirques and paternoster
   lakes.  These deposits may serve as localized
   sources of water.  Water tables ere typically
   shallow with coarse grained deposits present at
   the surface. Mountain glaciers may be present
   in some areas. Although precipitation may not be
   great, recharge is relatively high when
   compared to other settings in the region because
   of the large volumes of water produced from the
   glaciers during the summer melting cycle. These
I  recent glacial deposits are underlain by
I  fractured bedrock.






 Figure 2. Hydrogeolog/c setting card.
          O Show Key
          O Show Typical Characteristics

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  C. J.  Newell, J. F. Haasbeek, L P. Hopkins, S. E. Alder-Schaller, H. S. Rifai, P.
  B. Bedient, and G. A. Gorry. are with the Department of Environmental Science
  and Engineering, Rice Univcersity, Houston, TX 77251-1892.
  Joe R. Williams  is the EPA Project Officer (see below).
  The complete report, entitled "OASIS: Parameter Estimation System for Aquifer
        Restoration Models, User's Manual Version 2.0," (Order No. PB 90-181-
        314AS; Cost: $17.00, subject to change) will be available only from:
            National Technical Information Service
            5285 Port Royal Road
            Springfield, VA 22161
            Telephone: 703-487-4650
  The EPA Project Officer can be contacted at:
            R. S. Kerr Environmental Research Laboratory
            U.S. Environmental Protection Agency
            Ada, OK 74820
                                                                                            US.OFFICIAL MAIL'
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Environmental Protection
Agency
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Information
Cincinnati OH 45268
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Penalty for Private Use $300

EPA/600/S8-90/039

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