EPA
August 1990
A SUBTITLE D LANDFILL APPLICATION MANUAL
FOR THE MULTIMEDIA EXPOSURE
ASSESSMENT MODEL (MULTIMED)
by
Susan Sharp-Hansen1
Constance Travers1
Paul Hummel1
Terry Allison2
AQUA TERRA Consultants1
Mountain View, CA 94043
Computer Sciences Corporation2
Athens, GA 30605-2720
EPA Contract No. 68-03-3513
Project Monitor
Gerard Laniak
Environmental Research Laboratory
U.S. Environmental Protection Agency
Athens, GA 30605-2720
ENVIRONMENTAL RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
ATHENS, GEORGIA 30605-2720
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DISCLAIMER
The work presented in this document has been funded by the United States
Environmental Protection Agency. It has been subject to the Agency's peer and
administrative review, and has been approved as an EPA document. Mention of
trade names or commercial products does not constitute endorsement or
recommendation for use by the U.S. Environmental Protection Agency.
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FOREWORD
As environmental controls become more costly to implement and the penalties of
judgment errors become more severe, environmental quality management requires
more efficient management tools based on greater knowledge of the
environmental phenomena to be managed. As part of this Laboratory's research
on the occurrence, movement, transformation, impact and control of
environmental contaminants, the Assessment Branch develops management or
engineering tools to help pollution control officials assess the risk to human
health and the environment posed by land disposal of hazardous wastes.
EPA's Multimedia Exposure Assessment (MULTIMED) simulates the transport and
transformation of contaminants released from a hazardous waste disposal
facility into the multimedia environment. MULTIMED includes contaminant
release to either air or soil and possible interception of the subsurface
plume by a surface stream. An important application of MULTIMED would be the
prediction of pollutant movement in leachate from a Subtitle D landfill, a use
that requires only a subset of the model's full capabilities. This manual,
then, provides instruction for inexperienced as well as experienced model
users who seek to study or design waste disposal facilities.
Rosemarie C. Russo, Ph.D.
Director
Environmental Research Laboratory
Athens, GA
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ABSTRACT
The Environmental Protection Agency's Multimedia Exposure Assessment Model
(MULTIMED) for exposure assessment simulates the movement of contaminants
leaching from a landfill. The model consists of a number of modules which
predict concentrations at a receptor due to transport in the subsurface,
surface water, or air. This report is an application manual for the use of
MULTIMED in modeling Subtitle D land disposal facilities.
when applying MULTIMED to Subtitle D facilities, the landfill, surface water,
and air modules in the model are not accessible by the user; only flow and
transport through the unsaturated zone and transport in saturated zone can be
considered. A steady-state, one-dimensional, semi-analytical module simulates
flow in the unsaturated zone. The output from this module, water saturation
as a function of depth, is used as input to the unsaturated zone transport
module. The latter simulates transient, one-dimensional (vertical) transport
in the unsaturated zone and includes the effects of longitudinal dispersion,
linear adsorption, and first-order decay. The unsaturated zone transport
module calculates steady-state or transient contaminant concentrations.
Output from both unsaturated zone modules is used to couple the unsaturated
zone transport module with the steady-state or transient, semi-analytical
saturated zone transport module. The latter includes one-dimensional uniform
flow, three-dimensional dispersion, linear adsorption, first-order decay, and
dilution due to direct infiltration into the groundwater plume.
The fate of contaminants in the various media depends on the chemical
properties of the contaminants as well as a number of media- and environment-
specific parameters. The uncertainty in these parameters can be quantified in
MULTIMED using the Monte Carlo simulation technique.
To enhance the user-friendly nature of MULTIMED, a preprocessor, PREMED, and a
postprocessor, POSTMED, have been developed. The preprocessor guides the user
in the creation of a correct Subtitle D input file by restricting certain
options and parameters and by setting appropriate defaults.
This report was submitted in partial fulfillment of Work Assignment Number 32,
Contract Number 68-03-3513 by AQUA TERRA Consultants, under the sponsorship of
the U.S. Environmental Protection Agency. This report covers the period March
1990 to July 1990, and work was completed as of August 1990.
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TABLE OF CONTENTS
Section
Disclaimer ii
Foreword iii
Abstract iv
Figures ix
Tables xii
Acknowledgements xvi
1 . 0 INTRODUCTION 1
1.1 Overview of MULTIMED 1
1.1.1 Model Capabilities 1
1.1.2 Interaction Framework (AIDE) 3
1.2 Application of MULTIMED to Subtitle D Land Disposal
Facilities 3
1.3 Report Organization 4
1.4 How to Use this Manual 4
2 . 0 PROGRAM INSTALLATION AND EXECUTION 7
2.1 System Requirements 7
2.1.1 Hardware 7
2.1.2 Software 7
2.2 Loading the Executable Code 7
2.3 Executing and Verifying Test Sessions 8
3 . 0 FORMAT AND OPERATION OF THE PRE- AND POSTPROCESSOR 10
3.1 Screen Format 10
3.1.1 Data window 10
3.1.2 Assistance Window 12
3.1.3 Instruction Window 16
3.1.4 Command Line 16
3.2 Interaction Modes 17
3.3 Screen Movement 19
3.3.1 Movement within Screens 19
3.3.2 Movement between Screens 21
3.3.3 Screen Path 21
4 . 0 USE OF THE PRE- AND POSTPROCESSORS 23
4.1 The Preprocessor (PREMED) 23
4.1.1 Use of the Preprocessor 23
4.1.2 The PREMED Tutorials 38
4.2 The Postprocessor (POSTMED) 39
4.2.1 Use of the Postprocessor 39
5 . 0 MODEL APPLICATION 46
5 .1 MULTIMED Capabilities and Limitations 47
5.1.1 Solution Techniques 47
5.1.2 Spatial Characteristics of the System 49
5.1.3 Steady-state Versus Transient Flow and Transport.. 50
5.1.4 Monte Carlo Versus Deterministic Simulations 51
5.1.5 Boundary Conditions 52
5.2 Subtitle D Applications of MULTIMED 52
5.2.1 Summary of EPA Requirements for MULTIMED
Simulations of Leachate Migration from Subtitle D
Facilities 52
5.2.2 Active Modules 53
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5.2.3 Boundary Conditions 53
5.2.4 Procedures for Application of MULTIMED to
Subtitle D Facility Design 53
5.3 MULTIMED Input Requirements 56
5.3.1 Parameter Requirements Summarized by Module 57
5.3.2 Parameter Requirements Summarized by Data Group... 57
6 . 0 PARAMETER ESTIMATION 77
6.1 Chemical-Specific Parameters 78
6.1.1 Overall Chemical Decay Coefficient (Saturated
Zone) 78
6.1.2 Solid-Phase and Liquid-Phase Decay Coefficients
(Saturated Zone) 78
6.1.3 The Acid-Catalyzed and Base-Catalyzed Hydrolysis
Rates and the Neutral Hydrolysis Rate 78
6.1.4 Reference Temperature 79
6.1.5 Distribution Coefficient (Saturated Zone) 79
6.1.6 Normalized Organic Carbon Distribution
Coefficient 79
6.1.7 Biodegradation Coefficient (Saturated Zone) 80
6.2 Source-Specific Parameters 80
6.2.1 Recharge Rate 80
6.2.2 Infiltration Rate 80
6.2.3 Area of the Waste Disposal Unit 81
6.2.4 Length Scale of the Facility 81
6.2.5 width Scale of the Facility 81
6.2.6 Initial Concentration at Waste Disposal Facility.. 81
6.2.7 Source Decay Constant 81
6.2.8 Duration of Pulse 82
6.2.9 Spread of Contaminant Source 82
6.3 Unsaturated Flow Parameters 82
6.3.1 Saturated Hydraulic Conductivity 82
6.3.2 Unsaturated Zone Porosity 84
6.3.3 Air Entry Pressure Head 85
6.3.4 Number of Layers, Thickness of Layers 85
6.3.5 Residual Water Content 86
6.3.6 Brooks and Corey Exponent 86
6.3.7 Van Genuchten Parameters 86
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6 . 4
Unsaturated Transport Parameters
6.4.1 Number of Layers , Thickness of Layers
6.4.2 Longitudinal Dispersivity of Each Layer
6.4.3 Percent Organic Matter
6.4.4 Bulk Density of Soil for Layer
6.4.5 Biological Decay Coefficient
6 . 5 Aquifer-Specific Parameters
6.
6.
6.
6.
6.
6.
6.
6.
6.
6.
.5.
. 5 .
.5.
. 5 .
.5.
. 5 .
.5.
. 5 .
.5.
. 5 .
. 1
.2
.3
.4
.5
.6
. 7
.8
.9
.10
.5.11
.5.12
. 5 . 13
.5.14
Aquifer Porosity
Particle Diameter ..............................
Bulk Density ...................................
Aquifer Thickness ..............................
Source Thickness (Mixing Zone Depth) ...........
Hydraulic Conductivity .........................
Hydraulic Gradient .............................
Groundwater Seepage Velocity ...................
Retardation Coefficient ........................
Longitudinal, Transverse, and Vertical
Dispersivities .................................
Aquifer Temperature ............................
pH .............................................
Organic Carbon Content (Fraction) ..............
Well Distance from Site, Angle off Center, and
Well Vertical Distance .........................
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7.0
EXAMPLE PROBLEMS
7 .1 Example 1
7.1.1 The Hypothetical Scenario.
7.1.2 Input
7.1.3 Output
7.2 Example 2
7.2.1 The Hypothetical Scenario.
Input
Output
7.2.2
7.2.3
7.3 Example 3
7.3.1 The Hypothetical Scenario.
7.3.2 Input
7.3.3 Output
REFERENCES.
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110
124
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129
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APPENDIX A - CODE STRUCTURE AND INPUT DATA FORMAT..
A.1 Model Structure
A.2 Input and Output File Units
A.3 Common Blocks and Parameter Statements.
A.4 Structure of the Input Files
A. 4 .1
A. 4 .2
A. 4 .3
A. 4 .4
A. 4 . 5
Comment Cards.
Data Group/Subgroup Specification Card, End Card
and Data Cards
Specification of Parameter Values
The Array Subgroup
The Empirical Distribution Subgroup
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154
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159
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A. 5 Format of the Data Groups 159
A. 5.1 General Data Group 159
A. 5. 2 Source Data Group 159
A.5.3 Landfill Data Group 163
A. 5 . 4 Chemical Data Group 168
A. 5. 5 Unsaturated Flow Data Group 170
A. 5 . 6 Unsaturated Transport Data Group 184
A. 5. 7 Aquifer Data Group 186
A. 5. 8 Surface Water Data Group 189
A. 5. 9 Air Emissions and Dispersion Data Group 191
APPENDIX B - SUBROUTINES IN MULTIMED 201
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FIGURES
2.1 Preprocessor screen after installation 8
3 .1 Screen format utilized by the pre- and postprocessor 11
3.2 Example of a two window, one command line screen 12
3.3 Example of a three window, one command line screen 13
3.4 Example of a HELP assistance window 14
3 . 5 Example of a LIMITS assistance window 15
3.6 Example of information contained in a STATUS assistance window.. 16
3.7 Example of an ERROR message in the instruction window 17
4 .1 Opening screen of the preprocessor 23
4.2 Build/Modify screen of the preprocessor 24
4.3 Edit screen of the preprocessor 25
4 . 4 Create screen of the preprocessor 25
4 . 5 General-1 screen of the preprocessor 26
4 . 6 General-2 screen of the preprocessor 28
4 . 7 Edit screen of the preprocessor 28
4 . 8 AQuifer screen of the preprocessor 29
4 . 9 SOurce screen of the preprocessor 30
4 .10 Chemical screen of preprocessor 30
4.11 Unsaturated Flow (Funsat) screen of the preprocessor 31
4.12 Unsaturated Transport (Tunsat) screen of the preprocessor 31
4.13 The Depth screen of the preprocessor 32
4.14 The POrosity screen of the preprocessor for a deterministic
simulation 34
4.15 Screen for specification of aquifer porosity for a
deterministic simulation 34
4.16 Porosity screen of the preprocessor for a Monte Carlo
simulation 35
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4.17 Screen showing required parameters for a Lognormal
probability density distribution 35
4 .18 The Return screen of the preprocessor 37
4.19 The Save screen of the preprocessor 37
4.20 Example of a tutorial screen 38
4.21 Opening screen of the postprocessor 40
4.22 Data-1 screen of the postprocessor 41
4.23 Data-2 screen of the postprocessor 41
4.24 Specs screen of the postprocessor 43
4.25 Titles screen of the postprocessor 43
4.26 Example of a cumulative frequency plot 44
4.27 Example of a frequency plot 44
4.28 Example of screen showing a TEXT file 45
5.1 Procedure for using MULTIMED to assist in the design of
Subtitle D facilities 54
6.1 Schematic of the source thickness and the well location 97
6.2 Measured values of longitudinal dispersivity as a function
of path length over which dispersion is observed 101
6.3 Average temperatures of shallow groundwater in the
continental United States 104
A. 1 Subroutine organization tree for MULTIMED 149
A.2 Structure of the input data file, data groups, and subgroups.... 155
A.3 Key options available in the general data group pertaining to
the saturated zone transport module 164
A. 4 Key options available in the surface water module 195
A. 5 Key options available in the air modules 199
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TABLES
3-1 Commands for Application of PREMED 18
5-1 Issues to be Considered before Applying MULTIMED 48
5-2 Primary Parameters Used in the Saturated Zone Transport
Module for Subtitle D Applications of MULTIMED 58
5-3 Parameters Used to Derive Other Saturated Zone Transport
Module Parameters Needed in Subtitle D Applications of
MULTIMED 59
5-4 Parameters Required in the Unsaturated Zone Flow Module for
Subtitle D Applications of MULTIMED 61
5-5 Parameters Required in the Unsaturated Zone Transport
Module for Subtitle D Applications of MULTIMED 62
5-6 Parameters in the Chemical (Chemical) Data Group 64
5-7 Parameters Required for Selected Probability Density
Distributions 67
5-8 Parameters in the Contaminant Source (SOurce) Data Group 68
5-9 Parameters in the Aquifer (AQuifer) Data Group 69
5-10 Parameters in the Unsaturated Zone Flow (Funsat) Data Group.. 72
5-11 Parameters in the Unsaturated Zone Transport (Tunsat)
Data Group 75
6-1 Range of Hydraulic Conductivity Values for Various
Geologic Materials 83
6-2 Descriptive Statistics for Saturated Hydraulic Conductivity.. 84
6-3 Total Porosity of Various Materials 85
6-4 Descriptive Statistics for Saturation Water Content and
Residual Water Content 87
6-5 Descriptive Statistics for van Genuchten Water Retention
Model Parameters 88
6-6 Compilation of Field Dispersivity Values 90
6-7 Descriptive Statistics and Distribution Model for Organic
Matter (Percent by Weight) 91
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6-8
6-9
6-10
6-11
6-12 (a)
6-12 (b)
7-1
7-2
7-3
7-4
7-5
7-6
7-7
7-8
7-9
7-10
7-11
A-l
A-2
A-3
A-4
A-5
A-6
A-7
A-8
A-9
A-10
A-ll
Mean Bulk Density for Five Soil Textural Classifications
Descriptive Statistics for Bulk Density
Range of Soil Particle Sizes for Various Materials
Range and Mean Values of Dry Bulk Density for Various
Geologic Materials
Alternatives for Including Dispersivities in the Saturated
Zone Module
Probabilistic Representation of Longitudinal Dispersivity
for a Distance of 152.4 m
Input Sequence for Example 1
Output File for Example 1
SAT . OUT File for Example 1
Input Sequence for Example 2
Main Output File for Example 2
SAT . OUT File for Example 2
Monte Carlo Distribution Values in Example 3
Input Sequence for Example 3
Main Output File for Example 3
First Page of the SAT 1. OUT File for Example 3
STATS . OUT File for Example 3
Input Files Needed in MULTIMED
Output Files Generated by MULTIMED
Input Data Groups and Subgroups in MULTIMED
Distributions Available and their Codes
Contents and Format of a Typical Array Subgroup
Contents and Format of a Typical Empirical Distribution
Subgroup
Contents and Format of the General Data Group
Example of a Typical General Data Group
Contents and Format of the Source-Specific Data Group
Variables in the Source-Specific Array Subgroup
Contents and Format of the Landfill Module Control Data
Group
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A-12 Contents and Format of the Landfill Module Layer
Thickness and Material Data Subgroup 170
A-13 Contents and Format of the Landfill Module Liner Property
Subgroup 171
A-14 Variables in the Landfill Liner Property Array Subgroup 172
A-15 Contents and Format of the Landfill Module Material
Property Subgroup 173
A-16 Variables in the Landfill Material Property Array Subgroup... 174
A-17 Contents and Format of the Landfill Module Hydrology
Subgroup 175
A-18 Variables in the Landfill Hydrology Array Subgroup 176
A-19 Contents and Format of the Chemical-Specific Data Group 177
A-20 Variables in the Chemical Array Subgroup 178
A-21 Contents and Format of the Unsaturated Zone Flow
Module Control Data Group 179
A-22 Contents and Format of the Unsaturated Flow Module Layer
Thickness and Material Data Subgroup 181
A-23 Contents and Format of the Unsaturated Zone Flow Module
Material Property Subgroup 182
A-24 Variables in the Unsaturated Flow Material Property Array
Subgroup 183
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A-25 Contents and Format of the Unsaturated Zone Flow Module
Moisture Data Subgroup 184
A-26 Variables in the Unsaturated Flow Moisture Data Array
Subgroup 185
A-27 Contents and Format of the Unsaturated Zone Transport
Module Control Data Subgroup 187
A-28 Contents and Format of the Unsaturated Zone Transport
Module Properties Subgroup 189
A-29 Variables in the Unsaturated Transport Properties Array
Subgroup 190
A-30 Contents and Format of the Aquifer-Specific Data Group 191
A-31 Variables in the Aquifer Data Array Subgroup 192
A-32 Contents and Format of the Surface Water Data Group 193
A-33 Variables in the Surface Water Data Array Subgroup 194
A-34 Contents and Format of the Air Emission and Dispersion
Data Group 196
A-35 Variables in the Air Emission and Dispersion Data Array
Subgroup 197
A-36 Contents and Format of the Air Dispersion Control Data
Subgroup 198
A-37 General Structure of the Wind-Stability Frequency File
(FREQ. IN) 200
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ACKNOWLEDGEMENTS
This document was prepared under Work Assignment No. 32 of Contract No. 68-03-
3513 by AQUA TERRA Consultants for the U.S. Environmental Protection Agency
Office of Research and Development. Gerard Laniak of the Environmental
Research Laboratory in Athens, Georgia was the Technical Project Monitor and
Robert Carsel was the Project Officer. We thank them for their continuous
technical and management support throughout the course of this project.
At AQUA TERRA Consultants, the report was co-authored by Constance Travers and
Susan Sharp-Hansen, the Project Manager. Anthony Donigian supplied technical
and administrative guidance and he and John Kittle reviewed the document.
Word processing was performed by Dorothy Inahara. The material in Appendix A,
which summarizes the code structure and input format, and in Appendix B, which
lists the model subroutines, is based on a report by Salhotra and Mineart
(1988) .
A number of individuals were involved in the development and implementation of
the MULTIMED computational codes. Key individuals include Jan Kool and Peter
Huyakorn of HydroGeoLogic Inc., Terry Allison of Computer Sciences
Corporation, Barry Lester of Geotrans Inc., Michael Ungs of TetraTech, Inc.,
Bob Ambrose of U.S. EPA, John Kittle of AQUA TERRA Consultants, and Rob
Schanz, Yvonne Meeks, and Peter Mangarella of Woodward-Clyde Consultants.
The pre- and postprocessor for MULTIMED were developed by John Kittle and Paul
Hummel at AQUA TERRA Consultants. Paul Hummel and Constance Travers created
the tutorials for the preprocessor.
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SECTION 1
INTRODUCTION
This document provides information needed to apply the U.S. Environmental
Protection Agency's Multimedia Model (MULTIMED) to scenarios related to the
study and design of Subtitle D land disposal facilities. Application of
MULTIMED to Subtitle D facilities requires the use of only a subset of the
model's capabilities. MULTIMED's model theory documentation (Salhotra et al.,
1990) provides detailed information about the model's full capabilities. In
this section, the model's full capabilities are first briefly addressed
(Section 1.1). A summary of the methods used for application to the design of
Subtitle D facilities follows (Section 1.2).
1.1 OVERVIEW OF MULTIMED
MULTIMED simulates the transport and transformation of contaminants released
from a waste disposal facility into the multimedia environment. Release to
either air or soil, including the unsaturated and the saturated zones, and
possible interception of the subsurface contaminant plume by a surface stream
are included in the model. Thus, the model can be used as a technical and
quantitative management tool to address the problem of the land disposal of
chemicals in the multimedia environment. At this time, the air modules of the
model are not linked to the other model modules. As a result, the estimated
release of contaminants to the air is independent of the estimated contaminant
release to the subsurface and surface water.
MULTIMED utilizes analytical and semi-analytical solution techniques to solve
the mathematical equations describing flow and transport. The simplifying
assumptions required to obtain the analytical solutions limit the complexity
of the systems with can be represented by MULTIMED. The model does not
account for site-specific spatial variability, the shape of the land disposal
facility, site-specific boundary conditions, or multiple aquifers and pumping
wells. Nor can MULTIMED simulate processes, such as flow in fractures and
chemical reactions between contaminants, which can have a significant affect
on the concentration of contaminants at a site. In more complex systems, it
may be beneficial to use MULTIMED as a "screening level" model which would
allow a user to obtain an understanding of the system. A numerical model
could then be used if there are sufficient data and necessity to justify the
use of a more complex model.
1.1.1 Model Capabilities
During the development of this model, emphasis was placed on the creation of a
unified, user-friendly, software framework, with the capability to perform
uncertainty analysis, that can be easily enhanced by adding modules and/or
modifying existing modules.
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To enhance the user-friendly nature of the model, separate interactive
preprocessing and postprocessing software has been developed for use in
creating and editing input and in plotting model output. The pre- and
postprocessors, PREMED and POSTMED, have not been integrated with MULTIMED
because of the size limitations of PC computers. Therefore, after using the
preprocessor to create or modify input, the model is run in batch mode.
Afterwards, the postprocessor can be used to produce plots of the Monte Carlo
output or plots of concentration versus time for transient output.
The fate of contaminants critically depends on a number of media-specific
parameters. Typically many of these parameters exhibit spatial and temporal
variability as well as variability due to measurement errors. MULTIMED has
the capability to analyze the impact of uncertainty and variability in the
model inputs on the model outputs (concentrations at specified points in the
multimedia environment), using the Monte Carlo simulation technique.
The major functions currently performed by this model include:
• Allocation of default values to some input parameters/variables.
• Reading of the input data files.
• Echo of input data to output files.
• Derivation of some parameters, if specified by the user.
• Depending on user-selected options:
simulation of leachate flux emanating from the source
simulation of unsaturated zone flow and transport
simulation of saturated zone transport only
computation of in-stream concentrations due to contaminant
loading assuming complete interception of a plume in the
saturated zone
computation of the rate of contaminant emission from the
waste disposal unit into the atmosphere
simulation of dispersion of the contaminants in the
atmosphere
• Generation of random input values for Monte Carlo simulations.
• Performance of statistical analyses of Monte Carlo simulations.
• Writing the concentrations at specified receptors to output files
for deterministic runs. In the Monte Carlo mode, writing the
cumulative frequency distribution and selected percentiles of
concentrations at receptors to output files.
• Printing the values of randomly generated input parameters and the
computed concentration values for each Monte Carlo run.
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1.1.2 Interaction Framework (AIDE)
The pre- and postprocessor for MULTIMED have been developed using the ANNIE
Interaction Development Environment (AIDE) (Kittle et al. , 1989).
Consequently, the construction of input and the analysis of output is
standardized in terms of screen formats, movement within and between screens,
and methods of entering data, seeking on-line assistance and invoking
commands. A full explanation of the conventions used is provided in Section
3.
1.2 APPLICATION OF MULTIMED TO SUBTITLE D LAND DISPOSAL FACILITIES
The U.S. EPA has developed several restrictions for Subtitle D applications of
MULTIMED. These restrictions were made in an effort to develop a conservative
approach for simulating leachate migration from Subtitle D facilities.
• Only the Saturated and/or Unsaturated Modules may be active in
Subtitle D applications, because the Surface Water, Landfill and Air
Modules have not been sufficiently tested at this time.
• Although MULTIMED can simulate either steady-state or transient
transport conditions, only steady-state transport simulations are
allowed for Subtitle D applications. No decay of the source term is
allowed; the concentration of contaminants entering the aquifer
system must be constant in time. The contaminant pulse is assumed
continuous and constant for the duration of the simulation.
• The receptor must be located directly downgradient of the facility,
so that it intercepts the center of the contaminant plume. In
addition, the contaminant concentration must be calculated at the top
of aquifer. Therefore, the angle from the plume centerline to the
receptor and the vertical distance to the receptor must be specified
as zero in Subtitle D applications.
Thus, MULTIMED can be applied at many Subtitle D land disposal facility sites
to simulate the transport of contaminants from the source, through the
saturated and/or unsaturated zones by groundwater, to a receptor (i.e. a
well). when MULTIMED is used in conjunction with a separate source model,
such as HELP (Schroeder et al., 1984), it can be used in a variety of
applications. These applications include 1) development and comparison of the
effects of different facility designs on groundwater quality, 2) prediction of
the results of different types of "failure" of the landfill, and 3) if
leachate migration into the groundwater below an existing waste disposal
facility occurs, prediction of the fate and transport of the contaminants in
the subsurface. The user should bear in mind, however, that MULTIMED may not
be an appropriate model for application to some sites. This issue, which is
discussed in Section 5.1, should be considered before modeling efforts
proceed.
As stated above, MULTIMED can be used in the design process to demonstrate
that a particular design will adequately prevent contaminant concentrations in
groundwater from exceeding health-based thresholds. In other words, MULTIMED
combined with a source model can be used to demonstrate that either a landfill
design, or the specific hydrogeologic conditions present at a site will
prevent the migration of significant quantities of contaminants from the
landfill. Procedures have been developed for the application of MULTIMED to
the design of Subtitle D facilities. These procedures are outlined in Section
5.2.4 and are briefly summarized here.
• Collect site-specific hydrogeologic data
• Determine the contaminant to be simulated and the active modules in
MULTIMED and the point of compliance
• Propose a landfill design and determine the corresponding
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infiltration rate
• Run MULTIMED and calculate the dilution attenuation factor (i.e., the
factor by which the concentration is expected to decrease between the
landfill and the point of compliance)
• Based on the resulting dilution attenuation factor, determine if the
design is acceptable
1.3 REPORT ORGANIZATION
This report contains the information needed to apply MULTIMED, in conjunction
with another model, such as HELP (Schroeder et al., 1984 a and b), to Subtitle
D land disposal facilities. Section 2 contains information about installation
and execution of the code. In Section 3, general information about the format
and operation of the pre- and postprocessors is provided and Section 4
describes how to use the pre- and postprocessors for Subtitle D applications
of the model. Section 5 discusses the development of a conceptual model for
Subtitle D applications, the limitations and capabilities of MULTIMED, and
details about the input required to run each model module. Help in estimating
some of the model parameters is contained in Section 6. In Section 7,
appropriate example problems are included. Finally, contained in Appendices
are 1) detailed information on the structure of the code and the format of
data in the input files, and 2) a listing of the subroutines in the code.
1.4 HOW TO USE THIS MANUAL
This application manual for the MULTIMED model and its pre- and
postprocessors, PREMED and POSTMED, is designed to be used by inexperienced as
well as experienced users. Instructions are suggested for two types of
inexperienced users: the "hands-on, learn-as-you-go" user and the "read the
document first" user, as well as for the experienced user. An experienced
user is defined as one who is already familiar with the basic capabilities and
operational aspects of PREMED, MULTIMED and POSTMED, and wants to use the
programs to perform simulations. These instructions are based on a similar
set of instructions found in Imhoff et al. (1990).
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''Hands-on, Learn-as-you-go" Users
1. Read Section 2 for instructions on model installation and execution.
2. Install PREMED, MULTIMED, and POSTMED. Execute the tests provided
with the code and/or described in Section 2 to verify that PREMED and
POSTMED are properly installed.
3. From the DOS operating system, execute PREMED by typing (do
not type the brackets). The opening screen will appear. utilize one
of the two tutorials by typing either <@DETER.LOG> for a
deterministic Subtitle D application or <@MONTE.LOG> for a Monte
Carlo Subtitle D application.
4. Use the completed input sequence generated by the selected tutorial
to run MULTIMED. The input sequence created by the <@DETER.LOG>
tutorial is the same as that used in Example 2 in Section 7. The
input generated by the <@MONTE.LOG> tutorial corresponds to Example 3
in Section 7.
5. Examine the output generated by the MULTIMED model. Because new
versions of MULTIMED may be released after publication of this
document, the output may not be identical to the output shown in
Section 7. Therefore, compare the output generated by MULTIMED with
the appropriate output file provided with the code. This will allow
you to verify that the MULTIMED model is properly installed.
6. Try the other example problems described in Section 7 to become more
familiar with MULTIMED.
7. Practice producing plots using POSTMED and the SAT1.0UT file
generated when the Example 3 input is run.
8. Proceed with suggestions 2 through 5 provided below for "experienced
users."
''Read the Documentation First" Users
1. Read Section 1 to familiarize yourself with the basic capabilities
and framework of the MULTIMED model. If you need more detailed
information on the capabilities and limitations of MULTIMED to
determine if the model will be suitable for your needs, read Section
5.1.
2. Read Section 3 which discusses the format and basic operation of the
preprocessor, PREMED.
3. Read Section 2 for instructions on model installation and execution.
4. Install PREMED, MULTIMED, and POSTMED. Execute the tests provided
with the code and/or described in Section 2 to verify that PREMED and
POSTMED are properly installed.
5. From the DOS operating system, execute PREMED by typing (do
not type the brackets). The opening screen will appear. utilize one
of the two tutorials by typing either <@DETER.LOG> for a
deterministic Subtitle D application or <@MONTE.LOG> for a Monte
Carlo Subtitle D application.
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6. Section 4 discusses the use of the pre- and post-processor. Read
Section 4.1 in conjunction with the tutorial to provide a complete
description of PREMED.
7. Use the completed input sequence generated by the selected tutorial
to run MULTIMED. The input sequence created by the <@DETER.LOG>
tutorial is the same as that used in Example 2 in Section 7. The
input generated by the <@MONTE.LOG> tutorial corresponds to Example 3
in Section 7.
8. Examine the output generated by the MULTIMED model. Because new
versions of MULTIMED may be released after publication of this
document, the output may not be identical to the output shown in
Section 7. Therefore, compare the output generated by MULTIMED with
the appropriate output file provided with the code. This will allow
you to verify that the MULTIMED model is properly installed.
9. Try the other example problems described in Section 7 to become more
familiar with MULTIMED.
10. Practice producing plots using POSTMED and the SAT1.0UT file
generated when the Example 3 input is run.
11 . Proceed with suggestions 2 through 5 provided below for "experienced
users."
Experienced Users
1. Read Section 2 and install PREMED, MULTIMED, and POSTMED. Execute
the tests provided with the code and/or described in Section 2 to
verify that PREMED and POSTMED are properly installed, and execute
the test run for PREMED.
2. Read Section 5.2 which discusses applying MULTIMED to Subtitle D
facility problems. Refer to Section 5.1, which includes a discussion
of issues related to conceptualization of the system, and the
capabilities and limitations of MULTIMED, as needed.
3. Read Section 6 as needed to estimate parameters required by MULTIMED.
4. Try using MULTIMED to simulate actual scenarios.
5. If you wish to make changes to input files without using the
preprocessor, refer to Appendix A which discusses the format for
input files.
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SECTION 2
PROGRAM INSTALLATION AND EXECUTION
This section describes how to install and test MULTIMED and the related pre-
and postprocessor software on the user's computer. Hardware and software
requirements are discussed. Exact details of installation are included with
the software when it is distributed by the EPA Center for Exposure Assessment
Modeling (CEAM) at the Environmental Research Laboratory in Athens, Georgia.
If problems are experienced, the user should contact CEAM for support.
2.1 SYSTEM REQUIREMENTS
2.1.1 Hardware
MULTIMED and the related pre- and postprocessors, PREMED and POSTMED, were
designed to be used on an IBM-PC compatible computer. The PC must have 640 KB
of memory, a math coprocessor, and approximately 4 MB of free disk space.
Additional machines which should run the software include Digital Equipment
Corporation VAX computers running the VMS operation system, Prime 50 Series
computer running PRIMOS and Sun Microsystems workstations running UNIX.
Contact CEAM for details.
2.1.2 Software
MULTIMED and its related software are written in FORTRAN 77. If compilation
of the code is required, a FORTRAN compiler and linker are needed. In
addition, compilation of the preprocessor, PREMED, and postprocessor, POSTMED,
requires the use of ANNIE-IDE software (Kittle et al. , 1989), which is
available from CEAM. Graphics in the model postprocessor use the ANSI
Graphical Kernel System (GKS). If the graph features of the postprocessor are
to be used, then GKS device drivers are required for the user's output and
input devices. Consult CEAM for additional information about obtaining these
device drivers.
2.2 LOADING THE EXECUTABLE CODE
Included with the distribution media for MULTIMED and its related pre- and
postprocessing software is a README.1ST document and file that provides
detailed instructions for installing the programs. It is recommended that
data files be maintained in directories separate from the code.
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2.3 EXECUTING AND VERIFYING TEST SESSIONS
Sample input data files and the related output files are distributed with the
model. In order to test the installation of MULTIMED, the user should run
these example problems and compare the output generated by the code with the
output files supplied with the code. The code is executed on a PC by typing
MULTIMED ( is the enter key). The model will query the user for the
name of the input file and the name of the file to which output should be
written. Be careful not to overwrite existing output files.
In order to test the installation of the preprocessor, perform the following
check. First, execute the program (on a PC type PREMED). Next type the
following sequence of keys:
BCSMFURRYRY
Note that is the F2 function key. The screen in Figure 2.1 should appear
on the display screen. To return to the operating system, type the key R.
The best test of the installation of the postprocessor is to plot the results
of the Monte Carlo simulation distributed with the model. The output file is
called EX3SAT1.0UT. First, execute the program (on a PC type POSTMED).
Next, for plotting results to the screen type the following sequence of keys:
DEX3SAT1.OUTP
A cumulative frequency plot will appear on the computer screen. This plot
should be the same as the cumulative frequency plot found in the main output
file for the same problem. After examining the plot, press the Escape key,
Esc, to clear the plot from the screen. To return to the operating system,
type the key R.
For computers without graphics capabilities, the following check can be
performed. After executing the program (on a PC type POSTMED), type the
following sequence of keys:
DEX3SAT1.OUTS
At this point, hit the down arrow key once, then type PRP. The cumulative
frequency plot will be sent to the printer. After the plot has been sent,
return to the operating system by typing the key R.
If there is a problem with any of the three software components of MULTIMED,
review the installation instructions carefully before calling CEAM for
support.
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SECTION 3
FORMAT AND OPERATION OF THE PRE- AND POSTPROCESSOR
A pre- and a postprocessor, PREMED and POSTMED, have been developed for
MULTIMED in order to improve the ease with which input can be created and/or
edited and output can be analyzed. The pre- and postprocessors have been
developed using the ANNIE Interaction Development Environment (Annie-IDE)
(Kittle et al., 1989). Consequently, user interaction within the program is
standardized in terms of screen formats, movement within and between screens,
and methods of entering data, seeking on-line assistance and invoking
commands.
Two tutorials are distributed with the preprocessor (see Section 4.1.3 for
information about running the tutorials). These tutorials familiarize the
user with the operation and features of the preprocessor and are recommended
for new users. Although no tutorial exists for the postprocessor, its format
and operation are identical to that of the preprocessor. To complement the
tutorials, the format and operation of the screens are described in detail
below. The summary is taken, with minimal adaptation, from the manual for
another Annie-IDE application, called DBAPE (Imhoff et al., 1989).
3.1 SCREEN FORMAT
Figure 3.1 defines the basic layout of a preprocessor screen. The layout is
consistent for all screens used by PREMED, with specific kinds of information
always located at the same region of the screen. Screen information is
divided into four components: three windows (data window, assistance window,
instruction window) and the command line. For convenience, the dimensions,
content, and important features of the four screen components are summarized
along the periphery of the screen area in the figure.
3.1.1 Data window
The top portion of the screen is the data window. The data window contents
consist of one or more of the following.
(1) Prompts for user-supplied decisions by means of menu
selection
(2) Prompts for user-supplied data by means of form fill-in
(3) Echoes for current state of data
Two user-controlled sizes for the data window are used. In the default
layout, the assistance window is not displayed, resulting in a two window, one
commandline screen (see Figure 3.2 for example). If the user desires any of
the forms of assistance described in Section 3.1.2, then the data window is
reduced in size to accommodate the assistance window (see Figure 3.3).
Conversely, the assistance window can be eliminated from the screen, thus
expanding the data window, by invoking the QUIET command (). The pre- and
postprocessors accommodate up to 50 lines of data and enable scrolling in the
data window by using cursor keys when the data size exceeds the window size.
The title of the window and a series of one letter codes which identify the
sequence of screens which have led up to the current screen is displayed on
the upper left hand border of the data window. Further explanation of the
"screen path" feature is provided in Section 3.3.3.
3.1.2 Assistance Window
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Several types of user assistance are available within the pre- and
postprocessors. A layered approach to assistance is used as follows.
(1) Use of descriptive and unique words or abbreviations for
field or menu option names in the data window always
provides "first-cut" definitions.
(2) When space allows, additional information in the data
window near the data field or menu option clarifies the
desired information.
(3) If additional parameter- or screen-specific assistance is
available, it is supplied, upon request by the user, in
the assistance window. Two types of screen-dependent
assistance can be displayed in the assistance window:
HELP and LIMITS.
(4) If assistance of a global nature (i.e., independent of
individual screens) is available, it, also, is displayed
in the assistance window upon request by the user. The
three types of global assistance which can be displayed in
the assistance window are CMND, STATUS and XPAD.
The layered "help" in PREMED and POSTMED is designed so that the user must
specifically request the higher levels of assistance; consequently,
experienced users are not subjected to unnecessary information.
As specified above, the assistance window, which is located directly below the
data window (Figure 3.1), is used to display the more detailed levels of
assistance (HELP, LIMITS, CMND, STATUS and XPAD). All types of detailed
assistance are further described later in this section. The user selects one
assistance type at a time and the available assistance of that type is
displayed in the assistance window. The title of the window (i.e., HELP,
LIMITS, CMND, STATUS or XPAD) is displayed on the left portion of the upper
border for the window and corresponds to the type of assistance which has been
requested by the user. The types of assistance which are available for a
particular screen are indicated by the options listed in the command line
(Section 3.1.4). If the amount of available assistance exceeds the window
size, scrolling in the window by using cursor keys is allowed.
An example of screen layout for a three-window screen is shown in Figure 3.3.
Details on each of the assistance types which may be displayed within the
assistance window follow.
HELP
HELP assistance provides further information on model and system parameters
and menu options (see Figure 3.4). As noted above, HELP text is specific to a
particular screen and can be scrolled in the assistance window.
LIMITS
LIMITS displays the allowable values for a specific field in the data window.
LIMITS information may be (1) maximum and minimum acceptable numeric values or
(2) a list of acceptable alphanumeric values. LIMITS text is specific to the
field currently highlighted in the data window, and it, also, can be scrolled.
Figure 3.5 shows the type of information displayed in the assistance window
when LIMITS has been selected.
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CMND
CMND displays the names and definitions of all active commands at the current
location. The command definitions never change. It should be noted, however,
that the list of available commands varies according to location within the
program. For example, the STATUS command is available only at certain program
"levels." CMND text can be scrolled in the assistance window.
STATUS
STATUS assistance displays system status messages that summarize previous
actions and indicate the relative location of the user within the program
structure. A maximum of 10 lines of STATUS assistance may be viewed by the
user at any point within an application; STATUS assistance cannot be scrolled.
Figure 3.6 illustrates the type of information displayed in the STATUS
message. The screen contains the following information.
(1) Whether a file is being created or edited. If editing an
existing file, the file name is given.
(2) The type of application (i.e., a generic model application
or a Subtitle D application).
(3) The scenario being modeled (i.e., the MULTIMED modules
which have been selected by the user).
XPAD
Scratch pad (XPAD) assistance allows the user to write notes and reminders
during an interactive session. The user may record information in a single
XPAD with a maximum width of 78 characters and length of 10 lines. Regardless
of where the user is located within the interactive session, a request for
XPAD assistance will call up the same XPAD with the same information. XPAD
information in the assistance window can be scrolled. New notes can be added
to existing notes, and existing notes can be overwritten.
3.1.3 Instruction Window
The instruction window is always present on every screen. In the screen
layout, it is located below the data and assistance windows and directly above
the command line (see Figure 3.1). Two types of information are provided in
the window: instructions for the user's next keystroke or error messages
reporting incorrect keystrokes with instructions for corrective actions.
Depending on which type of information is displayed by the system, the window
title on the screen will be either "INSTRUCT" or "ERROR." Figure 3.5 gives an
example of the type of information commonly provided in an INSTRUCT-type
instruction window, and Figure 3.7 illustrates an ERROR-type instruction
window.
3.1.4 Command Line
The final component of the standard pre- and postprocessor screen is the
command line (Figure 3.1). The command line is restricted to one line. It
contains a menu of abbreviations for the available commands at the user's
current location within the program structure. Definitions of the abbreviated
commands are available by invoking the CMND assistance in the assistance
window.
Table 3.1 lists the commands available in PREMED, the function keys used to
invoke commands, and command definitions. Inspection of the command line in
Figure 3.1 shows that some of the commands are associated with the PC
functions keys and some are not. Instructions on the alternate methods for
invoking the various commands are provided in Section 3.3.
A final feature of the command line is mentioned here to avoid confusion. As
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will be explained in the following section, three interaction modes can be
utilized: data mode, command mode, and assist mode. The command line appears
on the screen when the user is utilizing either the data mode or the command
mode. when the user has invoked the assist mode, the command line is removed
from the screen to avoid confusion, and command instructions are displayed in
the instruction window. When the user leaves the assist mode to return to
either of the other two modes, the command line reappears.
3.2 INTERACTION MODES
User interaction is organized into three "modes," each with a specific
function:
(1) Use data mode to enter data or select from menu options in
data window.
(2) Use command mode to invoke commands or functions listed in
the command line; commands perform three functions:
(a) Allow exit from screens (NEXT, PREV).
(b) Manage assistance window (HELP, LIMITS, XPAD, STATUS,
CMND, QUIET).
(c) Manipulate data window (OOPS).
(3) Use assist mode to provide supplemental information in the
scratch pad (XPAD) on which to base subsequent actions or
to scroll up or down in the assistance window.
Note that most tasks performed will only require use of the data and command
modes.
TABLE 3-1. COMMANDS FOR APPLICATION OF PREMED
444444444444444444444444444444444444444444444444444444444444444444444444444444
Command Function
Name
CMND
Kev
Command Definition
Display definitions of commands in assistance
information window
DNPG
HELP
LIMITS
Display next page in data window.
Display HELP information in assistance
information window
Display limits of current field in assistance
information window
NEXT
OOPS
PREV
QUIET
STATUS
Go to next screen (sets screen exit status code
to 1)
Reset data values in data window to values when
screen was first displayed
Go to previous screen
Turn off assistance information window to allow
more room for data
Display system status in assistance information
window
XPAD
Display users scratch pad, allow changes
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14
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Movement from each of the interaction modes to the other modes can be
accomplished as follows.
data mode
data mode
to command mode
to assist mode
command mode to data mode
command mode to assist mode
assist mode to data mode
assist mode to command mode
- press key
- press function key associated with
appropriate type of assistance or
enter command mode and select
appropriate assistance from options
in command line
- press key
- select appropriate type of
assistance from options in command
line
- press key
- press key twice (goes
through data mode)
3.3 SCREEN MOVEMENT
Commands may be invoked either by pressing designated function keys or by
typing the first letter of a command name. Likewise, menu options may be
selected either by moving the cursor to the selection field and confirming, or
by typing the first letter (or letters, if needed) of the menu item.
Several general features of user communication should be noted:
(1) There are no restrictions to upper- or lower-case mode.
(2) A key or command is always used to invoke the same function.
(3) Function keys are only used to invoke commands.
3.3.1 Movement Within Screens
Movement within screens may consist of (1) movement between interaction modes,
(2) movement between the three windows and the command line, or (3) movement
within a window or command line. The first type of movement, between
interaction modes, has already been described in Section 3.2 and will not be
further considered here. Procedures which cause movement within and between
the three windows and the command line of a screen are outlined below. For
organization, the procedures which cause movement are categorized in terms of
the three interaction modes.
Data Mode--
In data mode, screen movement and operations may be accomplished by pressing
either printable character keystrokes, the or key, the cursor
keys or selected function keys. However, the result of pressing some of these
keys depends on the type of screen which is presently displayed.
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If one is prompted for decisions by means of a menu (i.e., a menu screen),
keystrokes cause the following results.
(1) Type the first letter (or more, if needed) of any option
in the menu in order to select the option.
(2) Use cursor keys to move between highlighted menu options.
(3) Press function keys designated on the command line to
invoke the following commands.
- HELP - NEXT - PREV - XPAD
If one is prompted for data by means of form fill-in (i.e., a data screen),
keystrokes cause the following results.
(1) Type alphanumeric characters needed to correctly fill in
the data screen; the characters will be inserted in the
screen at the cursor position.
(2) Press or to end entry in one data field
and move to another.
(3) Use cursor keys to move within and among data screen
fields as needed.
(4) Use function keys to invoke the following command
functions.
- HELP - NEXT - PREV - LIMITS
- XPAD
Command Mode--
In the command mode, three categories of keystrokes cause movement within
screens.
(1) All commands, with the exception of NEXT and PREV (see
Section 3.3.2), cause movement within screens. Type the
first character of any of these commands to invoke the
command and cause activity in either the data or the
assistance window. The activity caused by invoking each
command is summarized in Table 3-1. As described in
Section 3.1.2, the commands CMND, HELP, LIMITS, STATUS,
QUIET and XPAD cause activity in the assistance window.
The command OOPS, which resets values in data screen to
the values present when the screen was first displayed,
causes activity exclusively in the data window.
(2) Press the or key to execute the command
currently highlighted in the command line.
(3) Use the right or left cursor keys to move the highlighting
to another command along the command line.
Assist Mode--
While the user is in the assist mode, keystrokes cause no actions whatsoever
unless (1) the scratch pad (XPAD) is active or (2) information which can be
scrolled is contained in the assistance window. If the scratch pad is active,
typed characters are inserted into the scratch pad at the current location of
the cursor. The cursor can move in all directions, and pressing the
or key causes the start of a new line. Cursor keys can be used to
scroll up or down in any assistance window when the available assistance
exceeds the window height.
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17
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3.3.2 Movement Between Screens
A user can leave one screen and move on to another either by (1) selecting a
menu option in the data window or (2) invoking commands displayed on the
command line.
Menu Options- -
Selection of a menu option always leads to a new screen. From the data mode,
menu selections can be made by one of two methods.
(1)
(2)
Command Opt ions --
Type the first letter (or letters, if needed) of the menu
item.
Move the cursor by use of cursor keys to the selection
field and confirm by typing N.
Invoking either the NEXT or the PREV command results in movement to another
screen. From the command mode, command selections can be made by one of three
methods .
(1)
(2)
(3)
3.3.3 Screen Path
Type the first letter of the command.
Move the cursor by use of cursor keys to the selection
field in the command line and confirm by pressing .
For commands which are associated with a function key (as
indicated in the command line) , press the appropriate
function key.
During an interactive session, an aid is provided for remembering the sequence
of screens which have led up to the screen which is currently being displayed.
The screen path is connoted along the upper left hand border of the data
window following the window title (see Figure 3.7) . The screen path is a
series of one or two letter codes which identify both (1) the type of
operations and (2) the sequence of operations which have occurred from the
time the user leaves the opening screen until arriving at the current screen.
For example, a screen path "BCS" in the preprocessor signifies that the
current screen is a result of (1) selecting the Build option on the opening
screen, (2) opting to Create a new input file, and (3) selecting a Subtitle D
application.
As the user branches downward, a letter is added to the screen path each time
an operation is performed which results in the display of a new screen. The
letter corresponds to the first letter of the option selected in the previous
screen. In the case of some menus two letters are needed to differentiate
between options. In such cases, both letters are added to the screen path.
Conversely, upward movement, which is accomplished by using the Return option
in any menu, results in the elimination of a letter from the screen path.
It should be noted that familiarity with screen sequencing can also speed up
the time it takes to perform frequent tasks. After memorizing the screen path
needed to perform a sequence of operations and, hence, arrive at a particular
location in the program, one may type ahead and pass quickly over intermediate
screens .
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SECTION 4
USE OF THE PRE- AND POSTPROCESSORS
The preprocessor, PREMED, allows the user to easily create an input file for
use in MULTIMED. The postprocessor, POSTMED, provides a means of generating
graphs of concentration versus time and the results of Monte Carlo analysis.
Both of these programs are designed to be fully interactive and easy to use.
Many of the features and options available in the pre- and postprocessors are
discussed in Section 3.
4.1 THE PREPROCESSOR (PREMED)
4.1.1 Use of the Preprocessor
Before using the preprocessor, read the section on installation and execution
of MULTIMED (Section 2).
To execute the preprocessor, move to the directory which contains the
preprocessor and type (do not type the brackets). After a moment the
Opening screen will appear, as shown in Figure 4.1.
If you are unfamiliar with PREMED, it is strongly recommended that you utilize
the tutorials which are included with the preprocessor. These tutorials can
be accessed from the Opening screen by typing either <@DETER.LOG> or
<@MONTE.LOG> (do not type the brackets). The tutorials are discussed in
Section 4.1.3.
The Opening screen displays several options. At this time, only the
Build/Modify and Return (to operating system) options can be used. Currently
it is not possible to analyze model results or execute MULTIMED from the
preprocessor. You can analyze the results from Monte Carlo simulations using
the postprocessor, POSTMED. Viewing results or executing MULTIMED requires
that you return to the operating system.
You must use the Build/Modify option to create or edit an input file for
MULTIMED. Select this option by typing (do not type the brackets). The
Build/Modify screen will now be displayed as shown in Figure 4.2.
From this screen, you may either create, edit, or save an input sequence for
use in MULTIMED. If you select the Edit option (by typing ) you will be
prompted for the name of a preexisting input file (Figure 4.3). Type the name
of a file, and select the "Next" option by pressing to continue with the
program.
If you select the Create option, the Create screen will be displayed. Figure
4.4 shows the Create screen. This screen displays options for either a
Generic or a Subtitle D application of MULTIMED. Only Subtitle D applications
are discussed in this manual. Since it is intended for regulatory
application,the Subtitle D application of MULTIMED restricts the options
available for simulation to those which have been thoroughly tested.
Therefore, only the scenario involving the Unsaturated Zone and Saturated
Zones may be executed, and the Landfill, Surface Water, or Air Modules may not
be used. Furthermore, the Subtitle D-specific applications may only be run in
steady-state mode.
The next screen which will be displayed by PREMED is the General-1 (BEG)
screen. This screen allows input of information in the General Data group.
Figure 4.5 shows the appearance of the General-1 screen when the user has
chosen to create a Subtitle D input sequence. If a Generic application is
selected on the Create screen, then the default values on the General-1 screen
24
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will be different.
The Run Title is allowed a maximum of two lines. You may use any title for
your simulation that you want. In Subtitle D applications, the Run Option may
be either deterministic or Monte Carlo, but the simulation must be run in
steady-state. Factors which should be considered when selecting these options
are discussed in Section 5.
The various modules in MULTIMED which will be active in the simulation must be
selected. The Subtitle D application may include only the Saturated Zone
and/or Unsaturated Zone Modules. The Saturated Zone Module should be used
alone only if the water table is located directly below the bottom of the
waste disposal facility. In all other cases, the effects of unsaturated flow
and transport from the bottom of the facility to the water table cannot be
considered negligible, and the Unsaturated Zone Modules should be included in
the simulation. At this time, the other modules shown in Figure 4.5 (Surface
water, Air and Landfill) have not been sufficiently tested. Subtitle D
applications must be run in steady-state. After the General-1 parameters have
been specified, press for "Next" to move to the next screen.
If the Monte Carlo option is selected, the General-1 (BEG) screen will be
followed by the General-2 (BEG) screen (Figure 4.6). This screen requires the
following input: the number of Monte Carlo simulations, the desired output
from the model, and the confidence level (in %) for the 80th, 85th, 90th and
95th estimated percentiles. Estimation of the number of Monte Carlo
simulations and confidence levels are discussed in Section 6.6. The amount of
output is related to the number of output files which are opened by the model:
LOTS- Opens all ".VAR" and ".OUT" files (i.e., writes the Monte Carlo
variables for each simulation and the corresponding output) and the
main output file.
SOME- Opens only the main output file, "STATS.OUT" and "SAT1.0UT".
NONE- Opens only the main output file and "STATS.OUT". Note that the
postprocessor cannot be used if this amount of output is selected,
since POSTMED requires the "SAT1.0UT" file for the simulation.
After the General-2 (BEG) screen parameters have been set as desired, press
the to move to the next screen.
The Edit (BE) screen will now be displayed as shown in Figure 4.7. This
screen allows access to the nine data groups included in MULTIMED: the
General, AQuifer, Air, source, surface. Chemical, Funsat, Landfill and Tunsat
data groups. Not all of these data groups are required for a specific
simulation. For example, if the Air Module was not selected as an active
module on the General-1 (BEG) screen, then the Air data group option on the
Edit (BE) screen does not need to be selected. To determine which parameters
are required for a particular scenario (i.e., combination of MULTIMED
modules), refer to the section in the MULTIMED model theory documentation
(Salhotra et al., 1990) which describes the module.
The parameters in the General data group have already been specified on the
General-1 (and General-2) screens. However, if you wish to make changes to
this data group, type to select this option.
The Undef option on the Edit (BE) screen lists the data groups which contain
undefined parameters. This option is selected by typing . The data groups
displayed contain undefined parameters which will need to be defined before
the input sequence is complete for use in MULTIMED. To return to the Edit
screen, press the function key.
The other data group options on the Edit (BE) screen can be selected by typing
enough characters to make the selection unique. For example, there are two
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options which begin with "A", so if you wish to select the AQuifer data group,
you must type . Selection of a data group will be followed by a screen
which is specific to that data group, and contains a list of parameters or
parameter groups which are contained in that data group.
Six data groups contain parameters which are used in simulations of Subtitle D
facilities: General, AQuifer, source. Chemical, Funsat and Tunsat. The
General data group has already been discussed. The data group-specific
screens for each of the other groups are shown in Figures 4.8 through 4.12.
Each of these screens contains a Return (to Edit screen) option, and an option
to list Undefined parameters within the data group. Undefined parameters are
those which do not have a data value assigned to them. They are designated by
a -999 in the input file.
The rest of the options shown in the data-group specific screens are either 1)
parameter names or 2) sub-data groups which contain additional parameters.
For example, selection of the Type option on the AQuifer screen (Figure 4.8)
will be followed directly by a screen where a parameter value is specified.
In this case, the Type of source for the saturated zone model is specified.
However, selection of the Depth option on the AQuifer screen will be followed
by another screen which contains several parameters related to the size and
particle characteristics of the aquifer: PArticle diameter, POrosity of
aquifer. Bulk density. Depth of aquifer and Mixing zone depth. You will need
to select one of these options to specify actual values for the parameters.
Any of the options may be selected by typing enough characters to make the
selection unique.
The specification of a parameter value is similar for all of the parameters in
the data groups. Therefore, specification of the aquifer porosity will be
used as an example. The other parameters can be specified in a similar
manner.
From Table 5-8, it can be determined that the aquifer porosity is part of the
Depth and Particle Characteristics sub-data group which is part of the AQuifer
data group. Therefore, the AQuifer option should be selected from the Edit
(BE) screen by typing . PREMED will now display the AQuifer (BEAq) screen
as shown in Figure 4.8. This screen contains five sub-data groups: the Depth,
Type, Hydraulic, Misc and Times data groups. The aquifer porosity is included
in the Depth (and particle characteristics of the aquifer) sub-data group.
Select this option by typing .
The Depth (BEAqD) screen will now be displayed. Figure 4.13 shows this screen
which contains five parameters for which values may be specified: the
PArticle, POrosity, Bulk, Depth, and Mixing. Select the POrosity option on
the Depth (BEAqD) screen by typing . The screens which follow this
selection will differ for the Deterministic and Monte Carlo simulations. Both
types of simulations are discussed below.
Deterministic simulation:
Some of the parameters in MULTIMED may be derived from other
parameters instead of being specified directly by the user. The
aquifer porosity is one of these parameters which can be derived.
Therefore, the Depth screen is followed by the POrosity (BEAqDPo)
screen, shown in Figure 4.14, which provides two options: 1) Derive
the aquifer porosity value from other parameters in MULTIMED or 2)
Specify the value of the aquifer porosity. If the Derive option is
selected, PREMED will return to the Depth (BEAqD) screen. However,
if the Specify option is chosen, the preprocessor will display the
screen shown in Figure 4.15. The value of the aquifer porosity
should be entered on this screen. After the porosity has been
specified, press to return to the Size screen.
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Monte Carlo simulation:
The screens which will be displayed for a Monte Carlo simulation are
identical to those for a deterministic simulation until the value for
a specific parameter is to be input. In a Monte Carlo simulation,
the probability density distribution for each parameter required by
MULTIMED must be specified.
In the example discussed above, when the POrosity option is selected
from the Depth (BEAqD) screen, the screen which follows is shown in
Figure 4.16. The probability density distribution for the POrosity
is specified on this screen. It is very important that the
distribution selected adequately reflects the actual probability
density distribution for the parameter. A discussion of probability
density distributions is included in the MULTIMED model theory
documentation (Salhotra et al. , 1990).
Each of the distributions requires that some characteristics of the
distribution be specified. For example, if a LOGNormal distribution
is selected for the POrosity, the minimum and maximum values, the
mean and the standard deviation are required, as shown in Figure
4.17. The requirements for the different distributions are discussed
in Section 9 of the MULTIMED model theory documentation (Salhotra et
al. , 1990) .
Eventually, you will wish to exit the preprocessor. If you do not wish to
save any of the changes you have made to the input file, you may simply type
at any point and the program will be terminated. However, if you
would like to save your changes you will need to exit the program in the
following manner:
1. Select the Return option from the screen menus until you return to
the Edit (BE) screen.
2. Select the Return (to Build screen) option from the Edit screen.
3. If undefined parameters exist, the Return (BER) screen will be
displayed as shown in Figure 4.18. This screen lists the data groups
which contain undefined parameters. At this point, you may either 1)
Return to the Edit screen and specify the remaining undefined
parameters or 2) Return to the Build screen and ignore these
undefined parameters.
4. From the Build/Modify screen (Figure 4.2), select the Save option by
typing .
5. The Save (BS) screen will now be displayed as shown in Figure 4.19.
The name of the input file for use in MULTIMED should be specified on
this screen. Note that you should use a name which is compatible
with your computer system. For example, the DOS operating system on
an IBM PC will allow at most 8 characters in the main filename and 3
characters in the extension on the filename. Other operating systems
may have different restrictions. Press to return to the
Build/Modify screen.
6. To exit the program, select the Return (to Opening screen) option
from the Build/Modify screen by typing .
7. The execution of MULTIMED must be done from the operating system of
your computer. Therefore, select the Return (to operating system)
option from the Opening screen.
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4.1.2 The PREMED Tutorials
Two tutorials are included with the preprocessor. These tutorials are
intended to familiarize a user with the options and utilization of PREMED. It
is strongly recommended that an inexperienced user take advantage of the
tutorials provided with MULTIMED. Completion of these tutorials creates
complete input files for use in MULTIMED.
The tutorials are specific to the application of MULTIMED to Subtitle D
facilities. One tutorial generates an input file for deterministic, steady-
state simulation of flow and transport in the unsaturated zone, and transport
in the saturated zone. The second tutorial is similar to the first tutorial
except that it is run in a Monte Carlo framework. The input generated by the
Deterministic tutorial, and the corresponding MULTIMED output, are discussed
in Section 7.2. Input and output for the Monte Carlo tutorial are presented
in Section 7.3.
To utilize either of these tutorials, you must first begin the preprocessor
program by typing (do not type the brackets) from the DOS operating
system. After a few seconds, the Opening screen for the preprocessor will
appear. To activate the tutorials you must type either <@DETER.LOG> for the
Deterministic tutorial, or <@MONTE.LOG> for the Monte Carlo tutorial.
The tutorial will be presented in a small box on the right hand side of the
screen. An example of a tutorial screen is shown in Figure 4.20. Directions
for completing the tutorial will appear in this box. In the tutorial, you
will edit a pre-existing input file which is almost complete. This input file
has been specially designed to contain a small number of parameters which
still need values. These are called "undefined" parameters, and will need to
be supplied to the preprocessor in order to complete the input file. The
tutorial will provide instructions so that you can complete the file. In the
process, many of the options in the preprocessor will be demonstrated.
Successful completion of the tutorials will generate the completed input
sequence shown in Tables 7-4 and 7-7. These input sequences can then be used
to run MULTIMED and generate the output in Tables 7-5 and 7-8. Output from
the Monte Carlo tutorial, can be used with the postprocessor, POSTMED.
4.2 - THE POSTPROCESSOR (POSTMED)
The postprocessor can be used to generate plots to show the results of Monte
Carlo analyses or concentration versus time. These plots are generated from
the main output file and "SAT1.0UT" which are generated by MULTIMED during
execution. For comparison of different simulations, POSTMED allows up to
three different data files to be plotted on the same graph. Output from
POSTMED may be written to the screen, to a printer, to a plotter, or to a file
in text form.
4.2.1 Use of the Postprocessor
Before using the postprocessor, read the section on installation and execution
of MULTIMED (Section 2).
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In order to use POSTMED, you must copy the appropriate MULTIMED output file
into the directory which contains the postprocessor. For Monte Carlo Analyses,
the MULTIMED output file "SAT1.0UT" is used, which is generated automatically
during execution of MULTIMED. Note that the "SAT1.0UT" file will be
overwritten each time the model is run. Therefore, if you wish to save this
file for use with the postprocessor, you should rename it. This is
particularly important if you want to plot the results from more than one
simulation on the same graph; the "SAT1.0UT" files for each simulation must be
given a different name. For Concentration versus Time plots, the file which
should be copied into the POSTMED directory is the main output file. POSTMED
will select the information necessary for generating Concentration versus Time
plots from this file.
To execute the postprocessor, move to the directory which contains the
postprocessor and type (do not type the brackets). After a moment
the Opening screen will appear, as shown in Figure 4.21. Use the Data option
of the Opening screen to provide the postprocessor with information about
MULTIMED data files which you wish to plot. Type a (do not type the
brackets) to select this option.
POSTMED will now display the Data-1 (D) screen. The number of Multimedia
Model runs which you wish to plot should be entered on this screen. The valid
values which may be entered on this screen can be seen by pressing the
key. The limits for the parameter will then be displayed in the center,
assistance window, as shown in Figure 4.22. As you can see, a minimum of 1
and a maximum of 3 runs may be plotted on a single graph.
After entering a value on Data-1 (D) screen, select the "Next" option by
pressing to go to the next screen. The Data-2 (D) screen will now be
displayed (Figure 4.23). This screen is used to enter the name of the file(s)
which contain MULTIMED results to be plotted. This screen will appear once
for each run. After entering the name of the file, press to go to the
next screen.
After entering the last file, the postprocessor returns to the Opening screen.
Type to describe the specifications of the plot. POSTMED will now display
the Specs (S) screen as shown in Figure 4.24. Several options are available
on this screen.
1. The Graphics device must be specified. You may send the plot
generated by POSTMED to the screen (DISPLAY), a printer or a plotter.
If your computer will not support graphics, it may be desirable to
send the plot directly to a printer. Alternatively, the coordinates
used to generate the plot may be sent either to the screen or to a
TEXT file.
2. The X- and Y-axis types must be specified. Either arithmetic or
logarithmic scales may be used. Note that logarithmic scales can not
be used with FREQUENCY plots. If a logarithmic scale is selected,
the number of logarithmic cycles for each axis must be specified.
3. The location of the legend on the plot must be specified. The
options are: UL (upper left), LL (lower left) , UR (upper right), LR
(lower left).
4. You must specify the type of plot you wish to create. Three choices
are allowed: a cumulative frequency plot (CUMULATIVE), a frequency
plot (FREQUENCY) or a concentration versus time plot (TIME). The
FREQUENCY plot provides information about the number of times a
particular concentration was obtained, which is displayed in
histogram format. Selection of the CUMULATIVE option will generate a
plot showing the cumulative frequency of concentration values. The
TIME option plots concentration versus time for transient runs.
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5. The Y minimum and Y maximum (in percent) of the plot should be
specified. The minimum value must be less than the maximum.
To move between options, press . To select an option, type
enough characters to make the selection unique. For example, the Graphics
device options (Figure 4.24) are: DISPLAY, PRINTER, PLOTTER, TEXT, SCREEN. If
you wish to select DISPLAY, you may type only . However, if you want to
send your results to a printer, you must type two characters, , since
there are two options beginning with "P". Once you have selected the desired
options on the Specs (S) screen, press to return to the Opening screen.
Titles for the Graph, the x- and y-axis, and the different runs can be entered
on the Titles (T) screen. From the Opening screen, type for this
selection. This screen is shown in Figure 4.25. Any character string may be
used as a title. Use the to move between options. Press
to return to the Opening screen.
Now you are ready to generate a plot. If you wish to make any changes to the
any of the screens, type the first letter of the menu item to select the
option, make the necessary changes, and return to the Opening screen by
pressing . Otherwise, type to generate the plot. The plot will then
be sent to the Graphics device that you specified on the Specs (S) screen. A
cumulative frequency plot showing the results of the simulation of an example
problem is presented in Figure 4.26. The corresponding frequency plot is
shown in Figure 4.27. Figure 4.28 shows the first screen of the text file
generated by selecting the SCREEN option for the same example problem.
Selection of the TEXT option will send the same file to a specified file.
Now, you may either repeat the process described above and generate additional
plots, or type to return to the operating system.
30
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Figure 4.26
31
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Figure 4.27
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SECTION 5
MODEL APPLICATION
The large number of interrelated physical, chemical and biological processes
involved in the migration of leachates from waste disposal facilities makes
the prediction of groundwater contamination from these facilities a complex
task. Mathematical models are useful tools which provide insight into the
effects on groundwater quality of facility design, operation and failure.
All models are simplified representations of the real system; no model will
ever reproduce the exact characteristics of a site. Therefore, model results
should always be interpreted as estimates of groundwater flow and contaminant
transport, and not as exact predictions. Bond and Hwang (1988) recommend that
models be used for comparing various cases or scenarios, since all cases are
subject to the same limitations and simplifications. Furthermore, models are
useful for sensitivity analysis, determining the effects of varying one
parameter on the model results. It is important to understand the limitations
of mathematical models, and to use them correctly in evaluation of actual
environmental conditions.
Several recent reports present detailed discussions of the issues related to
model selection, application, and validation. Donigian and Rao (1988) address
each of these issues. Issues related to model selection and application are
addressed in detail by Boutwell et al. (1986). Weaver et al. (1989) discuss
the selection and field validation of mathematical models. In addition, a
report by the National Research Council (1990) discusses model application and
validation and provides recommendations for the proper use of groundwater
models. Model users, particularly those who are relatively inexperienced, are
encouraged to read these and similar reports before beginning a modeling
study.
The validity of the results from mathematical models depends to a large extent
on the proper application of the model. The application of a model to a
leachate migration problem requires several steps. First, the modeling needs
and the objectives of the study should be determined. Next, data should be
collected for characterization of the hydrological, geological, chemical and
biological conditions present in the system. These data should assist in the
development of the "scenario" to be modeled, which provides the framework for
the conceptual model of the system. The conceptual model and data are used to
verify that the selected model is appropriate. During model application,
results should be calibrated to obtain the best fit to observed data.
Finally, these results should be validated by comparing them to independently-
derived data or observations.
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In order to apply a model to a specific site, it is necessary to describe the
"scenario" to be represented by the model. A scenario is essentially a
description of all the important processes and characteristics of a particular
site. Although it may be possible to describe the "average" characteristics
of a Subtitle D landfill or surface impoundment, it would be dangerous to
assume that this description adequately describes all such facilities. Each
site is unique, and must be characterized separately. This section describes
some of the issues which should be considered when developing a scenario and
using MULTIMED to represent the conceptual model of the site.
One of the most severe limitations to modeling is insufficient data.
Uncertainty in model predictions results from our inability to characterize a
site in terms of the boundary conditions or the key parameters describing the
important flow and transport processes (National Research Council, 1990). The
results of MULTIMED are highly dependent on the quantity and quality of the
available data. The application of MULTIMED to a site requires the collection
of a large amount of data, and the process of applying MULTIMED to a scenario
may reveal data deficiencies which require additional data collection.
Based on the available data and the judgement of the modeler, values of the
required parameters should be determined. Parameter values which must be
determined for Subtitle D applications are discussed in Section 5.3. Section
6 of this manual provides guidance for estimation of parameters for use in
MULTIMED. Inexperienced modelers may attempt to apply the model when the lack
of site-specific data causes the model results to be highly speculative. It
must be emphasized that a mathematical model should never be used as a
substitute for data in site-specific applications.
As stated above, the conceptual model and data should be used to determine
whether or not a mathematical model is appropriate for representing the
subsurface system and which options in the model should be utilized. The
model should:
• Allow the objectives of the study to be achieved
• Adequately simulate the significant processes present in the actual
system
• Be consistent with the complexity of the study area
• Be appropriate for the amount of available data
Some of the factors which should be considered before applying MULTIMED to a
particular site are summarized in Table 5-1. This list is not exhaustive, and
is meant only to provide guidance. The factors in Table 5-1 are addressed in
terms of MULTIMED's capabilities and limitations in the following section.
5.1 MULTIMED CAPABILITIES AND LIMITATIONS
5.1.1 Solution Techniques
MULTIMED utilizes analytical and semi-analytical solution techniques to solve
the mathematical equations describing flow and transport. These solution
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TABLE 5-1. ISSUES TO BE CONSIDERED BEFORE APPLYING MULTIMED
4444444444444444444444444444444444444444444444444444444444444444444444444444
Objectives of the Study
• Is a "screening level" approach appropriate?
• Is modeling a "worst-case scenario" acceptable?
Significant Processes Affecting Contaminant Transport
• Does MULTIMED simulate all the significant processes occurring
at the site?
• Is the contaminant soluble in water and of the same density
as water?
Accuracy and Availability of the Data
• Have sufficient data been collected to obtain reliable results?
• what is the level of uncertainty associated with the data?
• Would a Monte Carlo simulation be useful? If so, are the
cumulative probability distributions for the parameters with
uncertain values known?
Complexity of the Hydrogeologic System
• Are the hydrogeologic properties of the system uniform?
• Is the flow in the aquifer uniform and steady?
• Is the site geometry regular?
• Does the source boundary condition require a transient
or steady-state solution?
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techniques have advantages and disadvantages over fully numerical models.
Analytical solutions are computationally more efficient than numerical
simulations and are more conducive to uncertainty analysis (i.e. Monte Carlo
techniques). Typically, input data for analytical models are simple and they
do not require detailed familiarity with the code or extensive modeling
experience. Analytical solutions are typically the most efficient alternative
when data necessary for the characterization of the system are sparse
(Javandel et al., 1984). The limited data available in most field situations
may not justify the use of a detailed numerical model; in some cases, results
from simple analytical models may be just as meaningful (Huyakorn et al.,
1986) .
However, analytical models require simplifying assumptions about the system
which are not necessary for numerical models. These simplifications result in
models which include relatively few processes and a limited number of
parameters which are often required to be constant in space and time (van der
Heijde and Beljin, 1988). MULTIMED is no exception; the representation of the
system simulated by the model is simple, and little or no spatial or temporal
variability is allowed for the parameters in the system.
Bond and Hwang (1988) present guidelines for determining whether the
assumption of uniform aquifer properties is justified at a particular site.
In more complex systems, it may be beneficial to use MULTIMED as a "screening
level" model which would allow a user to obtain an understanding of the
system. A numerical model could then be used if there are sufficient data and
necessity to justify the use of a more complex model.
A highly complex hydrogeological system cannot be accurately represented with
MULTIMED. Heterogeneous or anisotropic aquifer properties, multiple aquifers
and complicated boundary conditions cannot be simulated using this model.
MULTIMED cannot simulate processes, such as flow in fractures and chemical
reactions between contaminants, which can have a significant effect on the
concentration of contaminants at a site. Since each site is unique, it must
be left to the modeler to determine which conditions and processes are
important at a specific site, and to determine the suitability of applying
MULTIMED.
5.1.2 Spatial Characteristics of the System
Although actual landfills and groundwater systems are three-dimensional, it is
common to reduce the number of dimensions simulated in a mathematical model to
one or two. Two and three-dimensional models are generally more complex and
computationally expensive than one-dimensional models, and therefore require
more data. In some instances, a one-dimensional model may adequately
represent the system. Furthermore, the available data may not warrant the use
of a multidimensional model.
However, modeling a truly three-dimensional system using a one-dimensional
model may produce inaccurate results. Three-dimensional effects are often
very significant in describing processes such as contaminant plume migration.
The choice of the number of dimensions in the model should be made for a
specific site, based on the conditions present at that site. The information
which is desired from the model output should also be considered.
MULTIMED has the following spatial characteristics:
• The Unsaturated Flow Module simulates vertical, one-dimensional flow.
• The Unsaturated Transport Module simulates vertical, one-dimensional
transport. Dispersion is only considered in the longitudinal
(vertical) direction.
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• The Saturated Transport Module assumes one-dimensional, horizontal
flow. However, three-dimensional dispersion may be simulated since
the effects of lateral or vertical dispersion may significantly
affect the model results.
These spatial assumptions should be considered when applying MULTIMED to a
site. The assumption of flow only in the vertical direction may be valid for
facilities which receive uniform areal recharge. The assumption may not be
valid in facilities where surface soils (covers or daily backfill) or surface
slopes result in an increase of runoff in certain areas of the facility and
ponding of precipitation in others (Kirkham et al., 1986).
The simulation of one-dimensional, horizontal flow in the saturated zone
requires several assumptions. The saturated zone is treated as a single,
horizontal aquifer with uniform properties. The effects of pumping or
discharging wells on the groundwater flow system cannot be considered. These
assumptions should be considered when applying MULTIMED to a site.
5.1.3 Steady-State versus Transient Flow and Transport
The MULTIMED model assumes steady-state flow in all applications. Some
groundwater flow systems are in an approximate "steady-state", in which the
water entering the flow system is balanced by the water leaving the system.
There is no significant temporal variation in the system. The assumption of
steady-state conditions in a model generally simplifies the mathematical
equations used to describe processes, and reduces the amount of input data,
since no information about temporal variability is necessary.
However, assuming steady-state conditions in a system which exhibits transient
behavior may produce inaccurate results. For example, climatic variables,
such as precipitation vary in time and may have strong seasonal components.
In such areas, the assumption of constant recharge of the groundwater system
is incorrect. In general, this assumption will cause underestimation of
contaminant concentrations in the subsurface, since steady-state models can
not simulate the effects of individual storms, which can provide a substantial
driving force for contaminant transport.
MULTIMED can simulate either steady-state or transient transport conditions.
The assumption of steady-state transport requires that the contaminant source
has a sufficiently large mass to ensure that the downgradient concentration,
once reached, will be maintained (Mulkey et al., 1989). It must be assumed
that the source is continuous and constant. If these assumptions can not be
made at a particular site, inaccurate results will be produced by a steady-
state transport model. Steady-state models are also inappropriate when the
simulation includes chemicals which sorb or transform significantly (Mulkey et
al., 1989). Note that although the steady-state model can be very
conservative, this may be appropriate for some applications. The choice of
simulating steady-state or transient conditions should be made based the
objectives of the study and on the degree of temporal variability in the
system.
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5.1.4 Monte Carlo versus Deterministic Simulations
MULTIMED may be run in either a deterministic or a Monte Carlo framework. In
a deterministic simulation, exactly one model result is determined for a given
set of input values. All of the input variables are assumed to have a fixed
mathematical relationship with each other, which completely define the system.
Monte Carlo simulations, however, consider the intrinsic randomness and
uncertainties inherent in the system. The Monte Carlo method provides a means
of estimating the uncertainty in the results of a model, if the uncertainty of
the input variables is known or can be estimated. For each of the uncertain
variables, a cumulative probability distribution must be determined. The
Monte-Carlo technique involves running a model a large number of times with
different values of input parameters, which are determined from probability
distributions, and then analyzing the results. The Monte Carlo option is
discussed in Section 9 of the MULTIMED model theory documentation (Salhotra et
al., 1990).
There are many sources of uncertainty in the prediction of leachate migration
in the subsurface. Uncertainties may be due to measurement error in
parameters which describe the physical and chemical properties of the system,
the presence of spatial and temporal variability in the parameters, or
incompletely understood processes which are simulated by the mathematical
model. There may be some uncertainty associated with extrapolating data from
one set of conditions to a different set of conditions. Therefore, it may be
more appropriate to express these uncertain input parameters in terms of a
probability distribution rather than a single deterministic value and to use
an uncertainty propagation model to assess the effect of the variability on
the model output (Salhotra and Mineart, 1988) .
The specified uncertainty in the input parameters for MULTIMED is highly site-
specific. Available data for many sites are scarce and even sites which are
very well-characterized may exhibit a substantial amount of variability in
measured parameter values. Most of the parameters in the MULTIMED model may
be assigned a Monte Carlo distribution. It must be left to the user of the
MULTIMED model to determine which input parameter values are uncertain at a
particular site.
Although the Monte-Carlo method can be a useful tool for quantitatively
evaluating uncertainty in a model, it is not without problems. One difficulty
is related to determining the cumulative probability distribution for a given
parameter. These distributions must be determined from a large amount of
data, which may not be available. Assuming a parameter probability
distribution when the distribution is unknown does not help reduce
uncertainty, as the certainty of the output is then a function of the assumed
certainty of the input parameter (U.S. EPA, 1988) . Furthermore, in order to
obtain a valid estimate of the uncertainty in the output, the model must be
run numerous times (typically at least several hundred times) which can be
computationally expensive. These issues should be considered before utilizing
the Monte-Carlo technique.
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5.1.5 Boundary conditions
The source boundary condition for MULTIMED relates to the introduction of the
contaminant to the aquifer system. MULTIMED is limited to relatively simple
representations of the source of groundwater contamination. Only two types of
source geometries can be simulated by MULTIMED: a patch source or Gaussian
distributed source. Temporally, these source geometries may be described as
either: 1) continuous 2) exponentially decaying or 3) a non-decaying pulse of
finite duration. These types of sources are discussed in Section 5 of the
MULTIMED model theory documentation (Salhotra et al., 1990).
5.2 SUBTITLE D APPLICATIONS OF MULTIMED
5.2.1 Summary of EPA Requirements for MULTIMED Simulations of Leachate
Migration from Subtitle D Facilities
The U.S. EPA has developed several restrictions for Subtitle D applications of
MULTIMED. These restrictions were made in an effort to develop a conservative
approach for simulating leachate migration from Subtitle D facilities.
• Only the Saturated and/or Unsaturated Modules may be active in
Subtitle D applications, because the Surface Water, Landfill and Air
Modules have not been sufficiently tested at this time.
• Although MULTIMED can simulate either steady-state or transient
transport conditions, only steady-state transport simulations are
allowed for Subtitle D applications. No decay of the source term is
allowed; the concentration of contaminants entering the aquifer
system must be constant in time. The contaminant pulse is assumed
continuous and constant for the duration of the simulation.
• The receptor must be located directly downgradient of the facility,
so that it intercepts the center of the contaminant plume. In
addition, the contaminant concentration must be calculated at the top
of aquifer. Therefore, the angle from the plume centerline to the
receptor and the vertical distance to the receptor must be specified
as zero in Subtitle D applications.
• Only the Gaussian source geometry is allowed in SubtitappMcations.
The application of MULTIMED to Subtitle D facilities simulates the transport
of contaminants from the source, through the saturated and/or unsaturated
zones by groundwater, and to a receptor (i.e. a well). Although the Landfill
Module in MULTIMED can not be used at present because it has not been
sufficiently tested, MULTIMED can be used in conjunction with another source
model, such as HELP (Schroeder et al., 1984), to develop and compare the
effects of different facility designs on groundwater quality. MULTIMED
combined with a source model could be used to demonstrate that either the
landfill design, or the specific hydrogeologic conditions present at the site
will prevent the migration of significant quantities of leachate from the
landfill. Furthermore, MULTIMED could be used to predict the results of
different types of "failure" of the landfill. If leachate migration into the
groundwater below a waste disposal facility occurs, MULTIMED could be useful
in predicting the fate and transport of the contaminants in the subsurface.
5.2.2 Active Modules
Flow and transport in the subsurface typically occurs through the unsaturated
zone, to the water table and into the saturated zone. However, in some
instances, the water table may be located just below the waste disposal
facility, so that only saturated flow and transport away from the facility
need to be considered. Therefore, two basic simulation options are allowed
for Subtitle D applications of MULTIMED: 1) flow and transport in the
unsaturated zone coupled with transport in the saturated zone or 2) saturated
transport only. The simulation of the system should accurately represent the
52
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moisture conditions present at the site.
Simulation of these options in MULTIMED requires that the Saturated Zone
Module, and, if the water table is located at a significant depth below the
waste disposal facility, the Unsaturated Flow and Transport Modules, be
active. Use of the Saturated Zone Module requires four data groups: the
General, Chemical, Source, and Saturated Zone Data Groups. If the Unsaturated
Flow and Transport Modules are active, two additional data groups must be
used: the Unsaturated Flow and Transport Data Groups. The parameters required
in each of these data groups are discussed in Section 5.3.2.
5.2.3 Boundary conditions
Although MULTIMED can simulate two source geometries, only the Gaussian
distributed source is allowed in Subtitle D applications. Temporal variation
in the source term boundary conditions in MULTIMED are not allowed for
Subtitle D applications, which must be run in steady-state. Therefore,
although constant pulse and exponential decay boundary conditions are allowed
for generic applications of MULTIMED, only a constant source is allowed in
Subtitle D applications.
5.2.4 Procedure for Application of MULTIMED to Subtitle D Facility Design
MULTIMED can be used to assist in the design of Subtitle D landfills (Figure
5.1). As the flowchart shows, the role of MULTIMED in the design process is
to evaluate the ability of a particular design to insure that groundwater
concentrations of chemicals expected to exist in Subtitle D landfills do not
exceed health based thresholds. A step-wise procedure for determining the
minimum design necessary to protect groundwater at these levels and keyed to
the flowchart shown in Figure 5.1 follows:
1) Collect site-specific hydrogeological data. These data may include
aquifer particle size, porosity, bulk density, hydraulic conductivity
and gradient, groundwater velocity, dispersivities, and thickness.
53
-------
Figure 5 .1
54
-------
Lists and a discussion of the parameters required for Subtitle D
applications of MULTIMED are presented in Section 5.3. See Section 6
for guidance in parameter estimation.
Based on water level measurements, determine whether or not the
Unsaturated Zone Modules should be active in the simulation. If the
unsaturated zone will be simulated, collect site-specific data on the
properties of the unsaturated zone.
Determine contaminant which will be simulated. The selection of the
contaminant to be simulated may be based on a variety of factors or
it may be prescribed. It may be a chemical which is particularly
persistent in the subsurface environment, or is present in high
concentrations in the specific Subtitle D facility. Determine
chemical properties for the selected contaminant (see Section 6).
Propose landfill design and determine the infiltration rate at the
site. This can be done using a water balance model, such as HELP
(Schroeder et al., 1984), which includes representations of
engineering controls. Note that infiltration rate as used here means
the volumetric flow rate in meters per year from the bottom of the
landfill into the unsaturated zone or aquifer. Obviously, the
attenuation of this flow is the objective of landfill engineering
controls. For each specific landfill design, there is a resulting
steady-state infiltration rate.
Run MULTIMED using the Subtitle D application type, the
hydrogeological data collected in Step 1, the infiltration rate
determined in Step 2, and with the point of compliance set to the
required location. As discussed above, the Subtitle D application
assumes steady-state conditions and the point of compliance (POC)
must be along the plume centerline. You may wish to set the input
leachate concentration to 1.0 mg/1 for convenience in later
calculations (see step 6) .
The EPA-recommended criteria for establishing whether or not a
particular design is acceptable is based on the dilution-attenuation
factor (DAF). This method is based on the fact that the model
estimate of concentration at the point of compliance is linear with
respect to the input concentration. Therefore, the DAF is the factor
by which the concentration is expected to decrease between the
landfill and the point of compliance.
Using the concentration predicted by MULTIMED at the point of
compliance, the dilution-attenuation factor (DAF) for the
landfill/aquifer system may be calculated using the following
equation:
55
-------
DAF = leachate concentration / concentration at the POC
or, if the leachate concentration is 1.0 mg/1 in the model,
DAF = 1.0 / concentration at the POC
7) If the DAF is equal to or greater than 100, the design is acceptable
(see discussion below). Otherwise, the landfill design must be made
more stringent by increasing the number or effectiveness of
engineering controls so that the infiltration rate is reduced. To
evaluate the new design, repeat Steps 2-5. Continue until an
acceptable design is reached (DAF is equal to or greater than 100).
The threshold DAF of 100 is used to define an acceptable design because the
maximum allowable leachate concentration of chemicals expected to exist in a
Subtitle D landfill is 100 times the Maximum Contaminant Level (MCL) for each
chemical (U.S. EPA, 1990). This approach to determining the expected
concentration of constituents in leachate from a Subtitle D landfill is
attractive because of its consistency with other regulations and its generic
nature. If site-specific conditions permit the use of other approaches which
are acceptable to an approved state, these may be used.
5.3 MULTIMED INPUT REQUIREMENTS
As discussed above, the MULTIMED code consists of seven modules which are
described in Salhotra et al. (1990). Only three of the modules can be used
for Subtitle D applications of the model: the Saturated Zone Transport Module,
the Unsaturated Zone Flow Module, and the Unsaturated Zone Transport Module.
The Saturated Zone Transport Module is required for all Subtitle D
applications and can be applied independently of the Unsaturated Zone Modules.
Depending on site-specific conditions, the Unsaturated Zone Modules may or may
not be needed. Note that the two Unsaturated Zone Modules must be used in
conjunction with each other and with the Saturated Zone Module.
The operation of each module requires specific input, which is organized into
data groups. The General Data Group, which is required for all simulations,
contains flags and data which describe the scenario being modeled. The input
parameters needed for the Saturated Zone Transport Module are found in three
additional data groups: the Chemical Data Group, the Source Data Group, and
the Aquifer Data Group. Use of the Unsaturated Zone Modules requires input
found in the same data groups, as well as two others: the Unsaturated Zone
Flow Data Group and the Unsaturated Zone Transport Data Group.
In this section, parameter requirements are discussed in two stages. Section
5.3.1 introduces the input parameters required by each of the three modules
which can be active in Subtitle D applications. In Section 5.3.2, the
parameters in each data group are presented and the options available for
specifying their values in the code are summarized. Help in estimating these
parameters is provided in Section 6.
5.3.1 Parameter Requirements Summarized by Module
5.3.1.1 The Saturated Zone Transport Module--
The primary input parameters required to compute a contaminant concentration
in the saturated zone for Subtitle D applications are shown in Table 5-2,
organized according to the data group in which they are found. A number of
the parameters listed in Table 5-2 can be derived using other variables and a
set of empirical, semi-empirical, or exact relationships. Note that some of
the parameters used to derive the primary parameters can also be derived.
Table 5-3 indicates which parameters can be derived and lists the additional
variables needed. The methods used to derive the parameters are described in
Section 6 of this document or in Section 5.5 of Salhotra et al. (1990). Note
56
-------
that both particle diameter and porosity can not be simultaneously derived,
since one is derived from the other.
5.3.1.2 The Unsaturated Zone Flow Module--
The input parameters required to compute flow in the unsaturated zone are
shown in Table 5-4. Note that only one input variable in the Source Data
Group is needed. The remaining variables are all located in the Unsaturated
Zone Flow Data Group. None of these parameters can be derived.
5.3.1.3 The Unsaturated Zone Transport Module--
Table 5-5 lists the parameters used to compute contaminant transport in the
unsaturated zone. The variables are located in five different data groups.
Note that an overall chemical decay coefficient and distribution coefficient
for the unsaturated zone can not be entered directly, as they can in the
saturated zone module. Rather, they are calculated in the code using methods
described in Section 5.5.2.1 of Salhotra et al. (1990). Of the parameters
shown in Table 5-5, only the longitudinal dispersivity can be derived.
5.3.2 Parameter Requirements Summarized by Data Group
This section is written with the assumption that the modeler will use the
preprocessor, PREMED, to create and modify input files for Subtitle D
applications (see Section 4). Thus, the organization of the information in
this section is compatible with that of the preprocessor. The parameters are
listed in tables according to data group. Further, the parameters listed in
each of the data group tables are organized according to the preprocessor
screen in which they can be found. Advanced users, who choose to modify input
files directly without the use of the preprocessor, will notice that there is
some discrepancy between the organization of data in the preprocessor (and
this section) and the structure of the input file, which is discussed in
Appendix A.
5.3.2.1 General Data Group--
The General Data Group screens of the preprocessor contain flags which allow
the user to specify the run options and active modules for the input file.
The choices made in this data group determine which parameters must be
specified in
the rest of the input. Therefore, the General Data Group should always be
57
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TABLE 5-2. PRIMARY PARAMETERS USED IN THE SATURATED ZONE TRANSPORT MODULE
FOR SUBTITLE D APPLICATIONS OF MULTIMED
4444444444444444444444444444444444444444444444444444444444444444444444444444
Parameters
Units
Source Data Group Parameters
Area of the land disposal facility
Leachate concentration at the waste facility
Recharge rate into the plume
Infiltration rate from the facility
Standard deviation (i.e., spread) of the
source
Aquifer Data Group Parameters
Type of source geometry (only Gaussian allowed)
Porosity
Thickness of the aquifer
Thickness of source (i.e., mixing zone depth)
Seepage velocity
Dispersivities (longitudinal, transverse,
vertical)
Retardation coefficient
[dimensionless]
Radial distance from the site to the receptor
Chemical Data Group Parameters
Effective first-order decay coefficient
Distribution coefficient
[m2]
[mg/1, g/m3
[m/yr]
[m/yr]
[m]
[cc/cc]
[m]
[m]
[m/yr]
[m]
[m]
[1/yr]
[cc/g]
58
-------
TABLE 5-3. PARAMETERS USED TO DERIVE OTHER SATURATED ZONE TRANSPORT
MODULE PARAMETERS NEEDED IN SUBTITLE D APPLICATIONS OF MULTIMED
444444444444444444444444444444444444444444444444444444444444444444444444444444
Parameters
Units
Overall Chemical Decay Coefficient
Biodegradation rate
Solid phase decay coefficient
Dissolved phase decay coefficient
Bulk density
Distribution coefficient
Porosity
Solid and Dissolved Phase Decay Coefficients
Reference temperature
Aquifer temperature
Second-order acid-catalysis hydrolysis rate
constant at reference temperature
Second-order base-catalysis hydrolysis rate
constant at reference temperature
Neutral hydrolysis rate constant at reference
temperature
pH of the aquifer
Retardation Coefficient
Bulk density
Distribution coefficient
Porosity
Bulk Density
Porosity
Porosity
Mean particle diameter of the porous medium
Particle Diameter
Porosity
[1/yr]
[1/yr]
[1/yr]
[g/cc]
[cc/g]
[cc/cc]
[f/mole-yr]
[f/mole-yr]
[1/yr]
[pH units]
[g/cc]
[cc/g]
[cc/cc]
[cc/cc]
[cm]
[cc/cc]
(continued)
59
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TABLE 5-3. PARAMETERS USED TO DERIVE OTHER SATURATED ZONE TRANSPORT
MODULE PARAMETERS NEEDED IN SUBTITLE D APPLICATIONS OF
MULTIMED (concluded)
444444444444444444444444444444444444444444444444444444444444444444444444444444
Parameters
Units
Distribution Coefficient
Normalized distribution coefficient
for organic carbon, Koc
Fractional organic carbon content
[dimensionless]
Seepage Velocity
Hydraulic gradient
Hydraulic conductivity
Porosity
Hydraulic Conductivity
Porosity
Mean particle diameter of the porous medium
Thickness of the Source (Mixing Zone Depth)
Length of the land disposal facility
Thickness of the aquifer
Seepage velocity
Porosity
Infiltration rate through the facility
Vertical dispersivity
Standard Deviation of the Source
width of the land disposal facility
Length and Width of the Facility
Area of the land disposal facility
Dispersivities
Radial distance from the site to the receptor
[cc/g]
[m/m]
[m/yr]
[cc/cc]
[cc/cc]
[cm]
[m]
[m]
[m/yr]
[cc/cc]
[m/yr]
[m]
[m]
[m2]
[m]
60
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TABLE 5-4. PARAMETERS REQUIRED IN THE UNSATURATED ZONE FLOW MODULE
FOR SUBTITLE D APPLICATIONS OF MULTIMED
4444444444444444444444444444444444444444444444444444444444444444444444444444
Parameter Units
Source Data Group Parameters
Infiltration rate from the facility [m/yr]
Unsaturated Zone Data Group Parameters
Number of physical flow layers [dimensionless]
Number of porous materials [dimensionless]
Thickness of each layer [m]
Material associated with each layer [dimensionless]
For each material:
Air entry pressure head [m]
Porosity [dimensionless]
Saturated hydraulic conductivity [cm/hr]
Residual saturation (water content) [dimensionless]
Either:
van Genuchten alpha coefficient [I/cm]
van Genuchten beta coefficient [dimensionless]
or
Brooks and Corey exponent [dimensionless]
van Genuchten alpha coefficient [I/cm]
van Genuchten beta coefficient [dimensionless]
Note: The model provides the option to use either van GenuchtenTs or Brooks
and Corey's constitutive relationship for relative permeability
versus water saturation. However, the relationship between pressure
head and water saturation is expressed in terms of van Genuchten
parameters.
61
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TABLE 5-5. PARAMETERS REQUIRED IN THE UNSATURATED ZONE TRANSPORT MODULE
FOR SUBTITLE D APPLICATIONS OF MULTIMED
4444444444444444444444444444444444444444444444444444444444444444444444444444
Parameters
Units
[dimensionless]
[m]
[m]
[g/cc]
[1/yr]
[dimensionless]
[cc/cc]
Source Data Group Parameters
Source concentration at top of unsaturated zone [mg/f]
Unsaturated Zone Transport Data Group Parameters
Control parameters related to the evaluation
schemes used in the module
Number of layers used to simulate transport
For each layer:
Thickness
Longitudinal dispersivity
Bulk density of the soil
Biodegradation rate,
Percent organic matter
Unsaturated Zone Flow Data Group Parameters
Porosity of the unsaturated zone
Aquifer Data Group Parameters
Temperature of the aquifer3 [°C]
pH of the aquifer3 [pH units]
Chemical Data Group Parameters
Normalized distribution coefficient (i.e., Koc) [cc/g]
Reference Temperature [°C]
Acid and base hydrolysis rates at reference
temperature
[l/mole-yr]
Neutral hydrolysis rate at reference temperature [1/yr]
3 Note: the temperature and pH used in calculating the unsaturated zone
overall chemical decay rate are the temperature and pH specified for the
aquifer.
62
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completed first. The information which needs to be supplied for all model
applications is:
Title--Two lines of text can be entered. The text, which is used to label the
input and output, can consist of two character strings, each up to 78
characters in length.
Run Option--The default run option is Deterministic. However, the user has
the option of selecting a Monte Carlo run instead. Issues related to the
choice between these two options are addressed in Section 5.1.4. In addition,
Monte Carlo simulations are discussed in Section 9 of Salhotra et al. (1990) .
Active Modules--For Subtitle D applications, the default for active modules is
Unsaturated Zone/Saturated Zone. However, the user can choose that the
Saturated Zone alone be active. The Air, Landfill, and Surface Water Modules
can not be accessed for Subtitle D applications.
Transient versus Steady-state--For Subtitle D applications, the user has no
choice for this flag. Simulations must be steady-state.
For Monte Carlo simulations, additional information is required in the General
Data Group. The additional information is:
Number of Monte Carlo Simulations--Typically hundreds to thousands of Monte
Carlo simulations are needed to obtain meaningful results. Section 9.9 of
Salhotra et al. (1990) provides information on the estimation of this value.
Level of Output from Monte Carlo Runs--The default for this flag is SOME,
which means that the main output file and the STATS.OUT and SAT1.0UT files are
created (see Section A.2 for a description and listing of the output files).
The two other options available to the user are LOTS, which opens the maximum
number of output files, and NONE, which opens only the main and STATS.OUT
files. Note that in order to use the postprocessor to create frequency and
cumulative frequency plots, the file SAT1.0UT is needed and thus, this flag
must be set to either LOTS or SOME. A few of the files created using the LOTS
flag can be very large, depending on the number of Monte Carlo simulations.
On many PC computers, these files can fill all available disk space and cause
the simulation to fail. Thus, on PC's the default of SOME is recommended.
Confidence Level (in percent) for the Four Estimated Percentiles--ln Monte
Carlo mode, MULTIMED calculates confidence bounds for the 80th, 85th, 90th,
and 95th percentiles. The confidence bounds are discussed in Section 9.8 of
Salhotra et al. (1990).
5.3.2.2 Chemical Data Group--
The MULTIMED parameters contained in the Chemical Data Group are shown in
Table 5-6. Note that some of the parameters are associated with the Surface
Water and Air Modules of MULTIMED and thus, are not used for Subtitle D
applications of the model. Further, note that five of the parameters (i.e.,
the solid phase, liquid phase, and overall decay coefficients, the
distribution coefficient, and the biodegradation coefficient) are used only in
the Saturated Zone Module. Other parameters may be used by more than one
model module.
63
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TABLE 5-6. PARAMETERS IN THE CHEMICAL (Chemical) DATA GROUP
444444444444444444444444444444444444444444444444444444444444444444444444444444
Parameter [units] Derived Specified
Default
C N Ln Exp U LoglOU Emp
444444444444444444444444444444444444444444444444444444444444444444444444444444
Decay Coefficients:
Solid phase decay coeff. _______
(sat. zone) [1/yr]
Dissolved phase decay _______
(sat. zone) [1/yr]
Overall chemical decay _______
(sat. zone) [1/yr]
Hydrolysis Rate Constants and Reference Temperature:
Acid catalyzed _______
hydrolysis [1/M-yr]
Neutral catalyzed _______
hydrolysis [1/yr]
Base catalyzed _______
hydrolysis [1/M-yr]
SB
Comments
Value
Reference
temperature [oC]
Various Coefficients:
Normalized distribution
coeff. [ml/g]
Distribution coeff.
(sat. zone) [ml/g]
144
C = Constant
N = Normal
Ln = Lognormal
Exp = Exponential
U = Uniform
LoglOu = LoglOUniform
Emp = Empirical
SB = Johnson SB
G = Gelhar
64
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TABLE 5-6. PARAMETERS IN THE CHEMICAL (Chemical) DATA GROUP (concluded)
444444444444
Specified
N Ln Exp U LoglOU Emp
Parameter [units] Derived
Default Comments
C
Biodegradation coeff. _____
(sat. zone) [1/yr]
Air diffusion coeff.
Not used in Subtitle D
[cm2/s] applications.
Temperature for air
Not used in Subtitle D
diffusion [oC] applications.
Molecular Definitions, Solute Vapor Pressure, Henry's Constant:
Molecular weight [g/mole] Not used in Subtitle D applications.
Mole fraction of solute [--] Not used in Subtitle D applications.
Solute vapor pressure [mm Hg] Not used in Subtitle D applications.
Henry's Law const. [atm-m3/M] Not used in Subtitle D applications.
SB
Value
C = Constant
N = Normal
Ln = Lognormal
Exp = Exponential
U = Uniform
LoglOu = LoglOUniform
Emp = Empirical
SB = Johnson SB
G = Gelhar
65
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Table 5-6 indicates that four of the parameters in the Chemical Data Group can
be derived. If the user chooses to have the code calculate the values of
these parameters, additional parameters are needed (see Table 5-3). All of
the Chemical Data Group parameters can be assigned a constant value or, in
Monte Carlo mode, can be assigned one of seven Monte Carlo distributions. If
a Monte Carlo distribution is selected for any of the parameters, additional
information defining the distribution must be entered for that parameter (see
Table 5-7). The Monte Carlo distributions are described in Section 9.5 of
Salhotra et al. (1990). Also, limited help in determining the appropriate
Monte Carlo distribution for a particular parameter is provided in Section 6.
Most of the parameters are undefined initially in the preprocessor and must
have a value assigned to them before an input file can be completed. Note
that three of the parameters have a default value of zero assigned initially.
The default values can be changed at the user's discretion.
5.3.2.3 Source Data Group--
Table 5-8 lists the parameters in the Source Data Group. Note that in
Subtitle D applications the source is assumed to be continuous and non-
decaying. Therefore, two of the parameters, the duration of the pulse and the
source decay constant, can not be modified by the user. Refer to Tables 5-2
through 5-5 in order to determine which of the remaining parameters are needed
for specific model applications.
The values specified for the infiltration rate and the initial chemical
concentration entering the subsurface from the facility are difficult to
determine and yet are critical to the modeling effort. Refer to Section 5.2.4
for information about the values to use for these parameters when designing
Subtitle D facilities. Some general information is also provided in Section 6.
Three of the parameters listed in Table 5-8 can be derived. The derivation of
these parameters is described in Section 6 and Table 5-3 summarizes the
parameters needed for the derivations. All of the Source Data Group
parameters can be assigned a constant value or, in Monte Carlo mode, can be
assigned one of seven Monte Carlo distributions described in Section 9.5 of
Salhotra et al. (1990). Refer to Table 5-7 for a list of the additional
parameters required when a Monte Carlo distribution is specified for an input
parameter.
5.3.2.4 Aquifer Data Group--
The parameters in the Aquifer Data Group of the preprocessor are shown in
Table 5-9. This data group contains the largest number of parameters of all
the data groups, but many of them are "secondary" parameters (i.e., parameters
used to derive the "primary" parameters or other "secondary" parameters).
Depending on selections made by the user, some of these "secondary" parameters
may not be used by the code. Refer to Tables 5-2 and 5-3 and to Section 6 in
order to understand the relationships between these parameters and parameters
in other data groups.
66
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TABLE 5-7. PARAMETERS REQUIRED FOR SELECTED PROBABILITY DENSITY DISTRIBUTIONS
444444444444444444444444444444444444444444444444444444444444444444444444444444
Distribution
Normal
Lognormal
Exponential
Uniform
Log10uniform
Johnson SB
Empirical
Required Parameters
minimum, maximum, mean, standard deviation
minimum, maximum, mean, standard deviation
minimum, maximum, mean
minimum, maximum
minimum, maximum
minimum, maximum, mean, standard deviation
minimum, maximum, up to 20 pairs of data
defining the probability and
associated value (which describe the
distribution)
The parameters used to specify well location are restricted in Subtitle D
applications. Only the downgradient distance from the site can be input by
the user. Otherwise, it is assumed that the well is on the plume centerline
and screened at the top of the aquifer. The well angle off center and
vertical distance can not be modified, nor can they be assigned a Monte Carlo
distribution.
In the preprocessor, the geometry of the source boundary condition for the
aquifer is specified in the Aquifer Data Group. For Subtitle D applications,
only a Gaussian source is allowed which is described in Section 5 of Salhotra
et al . (1990) . Therefore, default value set in the preprocessor is Gaussian.
All of the Aquifer Data Group parameters which are not being derived can be
assigned either constant values or, in Monte Carlo mode, one of seven
distributions (see Table 5-9) . Note that an eighth distribution type is
available in Monte Carlo mode for the longitudinal, transverse, and vertical
dispersivities--the Gelhar distribution. This special distribution is
described in Section 6.5.10 and summarized in Table 6-12 (a) .
5.3.2.5 Unsaturated Zone Flow Data Group- -
Table 5-10 shows the parameters in the Unsaturated Zone Flow Data Group. The
parameters listed under the heading "Control Parameters" will influence the
type of data which can be input in this data group. Thus, these three
parameters should be specified first. Each has been assigned a default value
which can be changed based on site-specific information. The default values
are 1 flow layer, 1 material type, and the use of van Genuchten parameters to
determine the relationship between relative permeability and water saturation.
Note that the number of materials can never be greater than the number of
layers. Also note that the same material type can be assigned to more than
one layer.
67
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TABLE 5-8. PARAMETERS IN THE CONTAMINANT SOURCE (SOurce) DATA GROUP
444444444444444444444444444444444444444444444444444444444444444444444444444444
Parameter [units] Derived Specified
Default Comments
C N Ln Exp u LoglOU Emp SB G Value
Infiltration rate ________
[m/yr]
Area of waste unit ________
[m2yr]
Duration of pulse [yr] Not needed because Subtitle D applications must be steady-state
Spread of source _________
[m]
Recharge rate ________
[m/yr]
Source Decay constant _ 0
Set = 0 for Subtitle D applications
Initial concentration ________
[mg/1]
Length scale [m] _________
Width scale [m] _________
C = Constant Exp = Exponential Emp = Empirical
N = Normal U = Uniform SB = Johnson SB
Ln = Lognormal LoglOu = LoglOUniform G = Gelhar
68
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TABLE 5-9. PARAMETERS IN THE AQUIFER (AQuifer) DATA GROUP
Parameter [units] Derived
Default
Specified
C
N
Ln Exp u Log10U Emp
Depth and Particle Characteristics:
)))))))))))))))))))))))))))))))))))
Particle •
diameter [cm] porosity is derived.
))))))))))))
Porosity [--] ••
Cannot be derived if particle
diameter is derived.
Cannot be derived if aquifer
Bulk Density [g/cc]
Aquifer thickness
[m]
Source thickness
[m]
Type of Source (Gaussian or Patch) :
))))))))))))))))))))))))))))))))))))))))))
Hydraulic- and Dispersion-Related Parameters:
Hydraulic Conductivity
[m/yr]
Hydraulic gradient
Seepage velocity
[m/yr]
C
N
Ln
Constant
Normal
Lognormal
Gaussian
Exp = Exponential
U = Uniform
Log10u = Log10Uniform
Comments
SB
Value
Emp
SB
G
= Empirical
= Johnson SB
= Gelhar
69
-------
TABLE 5-9. PARAMETERS IN THE AQUIFER (AQuifer) DATA GROUP
Parameter [units] Derived _ Specified
Default
Retardation coeff.
Longitudinal
Dispersivity [m]
Transverse
Dispersivity [m]
vertical
Dispersivity [m]
Miscellaneous Parameters:
)))))))))))))))))))))))))
Temperature [ C]
Comments
N
Ln
Exp
u Log10U Emp
SB
Value
Organic carbon
content [fraction]
C = Constant
N = Normal
Ln = Lognormal
Exp = Exponential
U = Uniform
Log10u = Log10Uniform
Emp = Empirical
SB = Johnson SB
G = Gelhar
70
-------
TABLE 5-9. PARAMETERS IN THE AQUIFER (AQuifer) DATA GROUP (concluded)
[44444444444444444444444444444444444444444444444444444444444
Derived Specified
Parameter [units]
Default
Well -Related parameters:
Comments
C
N
Ln
Exp
U Log10U Emp
SB
Value
Receptor distance
from site [m]
Angle off center •
Set = 0 for Subtitle D applications.
Well vertical •
Set = 0 for Subtitle D
distance [fraction] applications.
Flag to reject wells
Not used in Subtitle D outside plume applications.
Times At Which to Calculate Concentrations:
C = Constant
N = Normal
Ln = Lognormal
Not used in steady-state
applications (steady-state
required for Subtitle D applications)
Exp = Exponential
U = Uniform
Log10u = Log10Uniform
Emp
SB
G
Empirical
Johnson SB
Gelhar
71
-------
TABLE 5-10. PARAMETERS IN THE UNSATURATED ZONE FLOW (Funsat) DATA GROUP
4444444444444444444444444444444444444444444444444444444444444444444444
Parameter [units] Derived Specified
Default Comments
C N Ln Exp u Log10U Emp SB G Value
Control Parameters:
Number of porous
materials
van Genuchten or van
Brooks/Corey flag Genuchten
Number of physical
flow layers
Layer Thickness and Material for Each Layer:
For 1 layer:
Depth of the unsat.
zone
For >1 layer:
Thickness [m]
For >1 layer:
Material number of
layers
Material Properties (for Each Material) :
Saturated hydraulic
conductivity [cm/hr]
Porosity [--]
C = Constant Exp = Exponential Emp = Empirical
N = Normal U = Uniform SB = Johnson SB
Ln = Lognormal Log10u = Log10Uniform G = Gelhar
72
-------
TABLE 5-10. PARAMETERS IN THE UNSATURATED ZONE FLOW (Funsat) DATA GROUP (concluded)
Derived _ Specified
Parameter [units]
Default
Air entry pressure
head [m]
C
N
Ln
Exp
Functional Coefficients (for each material) :
Residual water
content [--]
Brooks and Corey •••
Not needed if van Genuchten is
exponent [--] specified in control
parameters
Alpha van Genuchten
coeff. [I/cm]
Beta van Genuchten
coeff. [--]
C
N
Ln
Constant
Normal
Lognormal
Comments
u Log10U Emp
SB
Value
Exp = Exponential
U = Uniform
Log10u = Log10Uniform
Emp
SB
G
Empirical
Johnson SB
Gelhar
73
-------
When only one layer is modeled, its thickness is equal to the depth of the
unsaturated zone and the depth can be assigned a Monte Carlo distribution. when
multiple layers are simulated, their thicknesses must be assigned constant values.
Parameters related to material properties and functional relationships must be
specified for each material type being modeled. All of these parameters can be
assigned a constant value or, in Monte Carlo mode, one of seven Monte Carlo
distribution types. The specification of a Monte Carlo distribution requires
additional data defining the distribution be input (see Table 5-7). None of the
Unsaturated Zone Flow Data Group parameters can be derived.
5.3.2.6 Unsaturated Zone Transport Data Group--
The parameters contained in the Unsaturated Zone Transport Data Group are found in
Table 5-11. All of the parameters listed under "Control Parameters" have default
values associated with them. The number of layers is defaulted to 1, which
corresponds with the number of layers in the Unsaturated Flow Data Group. However,
under most conditions the number and thickness of transport layers need not
correspond to the number and thickness of flow layers. There are a couple of
restrictions: 1) the sum of the transport layer thicknesses must equal the sum of
the flow layer thicknesses, and 2) if the depth of the unsaturated zone is assigned
a Monte Carlo distribution in the Unsaturated Zone Flow Data Group (see Table 5-10),
only one transport layer is allowed.
Unless the modeler has a good understanding of the other "Control Parameters," it is
recommended that the default values be used.
For each transport layer being simulated, five parameters need to be specified. The
thickness of each layer must be assigned a constant value. The other four
parameters can have distributions assigned to them in Monte Carlo mode. Remember
that the specification of a Monte Carlo distribution requires that additional data
be supplied (see Table 5-7). The longitudinal dispersivity of each layer can be
either specified or derived. The derivation of this parameter is described in
Section 6.4.2.
74
-------
TABLE 5-11.
44444444;
Derived
Default
PARAMETERS IN THE UNSATURATED ZONE TRANSPORT (Tunsat) DATA GROUP
[444444444444
Specified
c
N
Ln Exp U Log10U Emp
Number of layers •
The number of layers need not
correspond to the number of
layers in Unsaturated Flow.
evaluation
for
18 is recommended value for
scheme Stehfest scheme (the default)
used •
interpolating cones.
Gaussian
integral
(for Each Transport Layer) :
))))))))))))))))))))))))))))))
Thickness of the layer [m]
dispersivity [m]
matter
44444
Constant
Exp
N = Normal
Ln = Lognormal
Exponential
SB
18
104
Emp = Empirical
U = Uniform SB
Log10u = Log10Uniform G
Parameter [units]
Comments
Value
Control Parameters:
Scheme for
Stehfest
Number of terms
Number of points
for
Number of
points
Convolution
segments
Property Parameters
Longitudinal
Percent organic
Johnson SB
Gelhar
75
-------
TABLE 5-11. PARAMETERS IN THE UNSATURATED ZONE TRANSPORT (Tunsat) DATA GROUP (concluded)
Derived Specified
Default Comments
C N Ln Exp u Log10U Emp SB G Value
[g/cc] • • ••••••
))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))) Biological decay
• • ••••••
coeff. [1/yr]
Constant Exp = Exponential Emp = Empirical
N = Normal U = Uniform SB = Johnson SB
Ln = Lognormal Log10u = Log10Uniform G = Gelhar
76
-------
SECTION 6
PARAMETER ESTIMATION
This section is intended to provide guidance for estimating parameters required by
MULTIMED for Subtitle D land disposal facility applications. It is not intended in any
way to be used as a substitute for data collection. Reported values are presented to
demonstrate appropriate ranges of values for particular parameters. For easy
reference, the parameters are grouped according to the model data group with which they
are associated.
The most accurate model results will be obtained from simulations which are based on
site-specific data collection. In some cases, however, it is not feasible to measure
certain parameters, and satisfactory results have been obtained using estimated values.
The code contains the option to internally derive some parameters based on other input
parameters. It is recommended that this option be used with caution and only when
values from measurements at the site are not available. The parameters that can be
derived are identified in this section. The methods used in the code to calculate the
derived parameters are summarized briefly in this section, and are discussed in more
detail in the MULTIMED model theory documentation (Salhotra et al. , 1990).
There are many sources of uncertainty in the prediction of contaminant migration in the
subsurface. Utilizing the Monte Carlo option in the model is a method to determine the
effect of uncertainty in the model input on the model results. In this option, a
parameter is assigned a distribution and its value is then randomly generated. It is
often difficult to determine the cumulative probability distribution for a given
parameter. These distributions must be determined from a large amount of data, which
may not be available. Assuming a parameter probability distribution when the
distribution is unknown does not help reduce uncertainty, as the certainty of the
output is then a function of the assumed certainty of the input parameter (U.S. EPA,
1988) .
Some guidance on determining an appropriate probability density distribution for
specific parameters is provided in this section, when possible, tables of descriptive
statistics are also given. This information can be ignored if the model is run in a
deterministic framework. General information related to the probability distributions
and help in determining the number of Monte Carlo runs needed is provided in Section
9 of the MULTIMED model theory documentation (Salhotra et al., 1990).
77
-------
6.1 CHEMICAL-SPECIFIC PARAMETERS
6.1.1 Overall Chemical Decay Coefficient (Saturated Zone) Fl/yrl
This parameter can be derived by the code, which computes it by summing the solid and
liquid phase decay coefficients for the saturated zone. Note that the overall chemical
decay coefficient does not include biological decay; the biodegradation coefficient
must be specified separately. If the value for the overall chemical decay coefficient
is specified by the user as a constant or a distribution, the solid and dissolved phase
decay coefficients are not needed. In general, the overall decay coefficient for the
saturated zone will be smaller in value than for the unsaturated zone.
6.1.2 Solid-Phase and Liquid-Phase Decay Coefficients (Saturated Zone) Fl/yrl
These decay coefficients represent the hydrolysis rate constants for the saturated
zone. They do not include biological decay, which is discussed in Section 6.1.7.
Hydrolysis is a potentially significant elimination pathway for many organic chemicals
(Lyman et al. , 1982). For compounds which are easily biodegraded, however, hydrolysis
may be insignificant relative to biodegradation (see Section 6.1.7). The hydrolysis
of organic chemicals can be described as a first-order rate process with respect to the
concentration of the organic species (Faust and Gomaa, 1972; Wolfe et al. , 1977; 1978)
and is dependent on temperature, pH, adsorption, and the presence of organic solvents.
Methods for estimating the rate constant for the hydrolysis process are presented in
Lyman et al. (1982) .
The solid-phase and liquid-phase hydrolysis rate constants can be derived in the code,
using input for the acid, base, and neutral hydrolysis rate constants, the reference
temperature, and the temperature and pH of the aquifer. The method used by the code
to derive these parameters is discussed in Section 5.5.2.1 of the MULTIMED model theory
documentation (Salhotra et al. , 1990). The use of acid, base, and neutral hydrolysis
rates takes into account the strong pH dependence of this process.
If the values of both the solid and dissolved phase decay coefficients are specified
by the user, then the saturated transport module does not use the values of the acid,
base, and neutral hydrolysis rate constants. They are needed, however, if unsaturated
transport and/or surface water transport are also being simulated.
6.1.3 The Acid-Catalyzed and Base-Catalyzed Hydrolysis Rates Fl/M-yrl and
the Neutral Hydrolysis Rate Fl/yrl
These three parameters are used in the code to calculate the overall chemical decay
coefficient for the unsaturated, saturated, and surface water modules. The use of
these parameters in the unsaturated and saturated transport modules is described in
Section 5.5.2.1 of Salhotra et al. (1990). For the surface water module, refer to
Section 6.2.1 of the same document. Values of these hydrolysis rate constants are
available in a large number of references, including Lyman et al. (1982), Mabey et al.
(1982), and Mills et al. (1985a) .
78
-------
6.1.4 Reference Temperature r°C1
The reference temperature is the temperature at which K^b and K^r were calculated and
is normally provided along with the hydrolysis rate constant data.
6.1.5 Distribution Coefficient (Saturated Zone) Fml/gl
Sorption refers to the accumulation of a chemical in the boundary region of a solid-
liquid interface (Mills et al., 1985a). Because sorption retards chemical transport
in the subsurface, the fate of a chemical is highly dependent on its sorptive
characteristics (i.e., the distribution between the sorbed and dissolved phases) .
MULTIMED assumes that a linear equation can describe the relationship between the
equilibrium concentrations of the dissolved and adsorbed phases. The linear
relationship requires knowledge of the chemical distribution coefficient, Kd. A number
of studies have developed empirical relationships for the partition coefficient. The
relationship most suited for relating the chemical distribution coefficient to soil or
porous medium properties is discussed in detail by Karickhoff (1984).
In the absence of a user-supplied value, the chemical distribution coefficient for the
saturated zone, Kd, can be derived by the code. Hydrophobic binding is assumed to
dominate the sorption process and thus, the distribution coefficient is related
directly to soil organic carbon content using:
Kd = Kocfoc (6.1)
where
K = normalized distribution coefficient for organic carbon [mf/g]
foe
= '
fraction]
foc = organic carbon content in the saturated zone [dimensionless
The estimation of the normalized distribution coefficient for organic carbon is
discussed below.
6.1.6 Normalized Organic Carbon Distribution Coefficient Fml/gl
The normalized organic carbon distribution coefficient, Koc, is used in the code to
calculate the chemical distribution coefficient in the unsaturated transport and the
surface water modules. It is also used in the saturated transport module when the user
chooses to derive the chemical distribution coefficient. There are many published
lists of values for Koc. Data are available primarily for pesticides and, to a lesser
degree, aromatic and polycyclic aromatic compounds. Lyman et al. (1982) recommend ten
different references which contain values of Koc.
If data on Koc are not available for a particular chemical, a value can be estimated
from empirical relationships between Koc and some other property of the chemical such
as the water solubility, S, the octanol-water partition coefficient, Kow, or the
bioconcentration factor for aquatic life, BCF. Lyman et al. (1982) tabulate 12 such
regression equations obtained from data sets of different classes of chemicals, and
present guidelines for selecting an accurate and applicable equation for a particular
chemical. Values for the octanol-water partition coefficient and solubility of
priority pollutants are available in many references, including Mabey et al. (1982) and
Mills et al. (1985a) .
6.1.7 Biodegradation Coefficient (Saturated Zone) n/yrl
Biodegradation, along with hydrolysis, is one of the decay pathways considered by
MULTIMED. For many contaminants, biodegradation is the most significant means of
removal from the subsurface environment. However, the biodegradation of chemicals in
the environment is complex, depending on a number of variable and/or unknown factors,
such as the number of microorganisms present, the availability of oxygen and other
nutrients, and the pH and temperature of the system.
A first-order kinetic relationship is normally used to represent biodegradation in the
natural environment. It is difficult to estimate the biodegradation coefficient needed
79
-------
in this relationship. Although attempts have been made to correlate the
biodegradability of a compound with its molecular characteristics, such as solubility,
these generalizations are applicable only to the specific chemicals investigated, and
are not recommended estimation techniques for other chemicals (Lyman et al. , 1982) .
A significant amount of work is needed to validate the extension of these techniques
to other chemicals and conditions.
A compilation of laboratory-derived biodegradation rate constants reported in the
literature, along with the test conditions when available, is presented in Lyman et al.
(1982). The tables include rate constants for several organic compounds in both
aqueous environments and soils. However, since these constants were determined under
laboratory conditions, they may be inapplicable to a field situation. Additional data
are available in Mills et al. (1985a) and Mabey et al. (1982). Care should be taken
in extrapolating the results shown in any of these tables to actual environmental
situations.
6.2 SOURCE-SPECIFIC PARAMETERS
6.2.1 Recharge Rate Fm/yrl
The recharge rate in this model is the net amount of water that percolates directly
into the aquifer system outside of the land disposal facility. The recharge is assumed
to have no contamination and hence dilutes the groundwater contaminant plume. The
recharge rate into the plume can be calculated in a variety of ways. One possibility
is to use a model, such as HELP (Hydrologic Evaluation of Landfill Performance)
(Schroeder et al. , 1984), without any engineering controls (leachate collection system
or a liner) to simulate the water balance for natural conditions. Results of such an
analysis have been presented by E.G. Jordan Co. (1985, 1987).
6.2.2 Infiltration Rate Fm/yrl
The infiltration rate is the net amount of leachate that percolates into the aquifer
system from a land disposal facility. Because of the use of engineering controls and
the presence of non-native porous materials in the landfill facility, the infiltration
rate will typically be different than the recharge rate. However, it can be estimated
by similar methods as those discussed for estimation of the recharge rate.
6.2.3 Area of Waste Disposal Unit I'm2"!
The area of the waste disposal unit will vary significantly from site to site. The
area should be directly measured and input by the user.
6.2.4 Length Scale of Facility [ml
The length of the waste disposal facility should be measured at the site.
However, this parameter can be derived by the code. The derivation is based on the
assumption that the waste disposal facility has a square shape. Therefore, the code
takes the square root of the area:
L = (AJ* (6.2)
6.2.5 Width Scale of Facility Fml
The width of the waste disposal facility should be measured at the site.
However, as was true for the length scale of the facility (Section 6.2.4), this
parameter can be derived by the code, which calculates the width of the facility as the
square root of the area.
80
-------
6.2.6 Initial Concentration at Waste Disposal Facility Fmg/11
When possible, site-specific data should be used. However, the user should bear in
mind that concentrations are quite variable over time and thus, a limited set of data
may not be representative of conditions at the facility. If data are not available,
a conservative approximation would be the solubility of the contaminant in water.
When using the model for the design of Subtitle D facilities, a value of 100 times the
Drinking Water Standard can be used (see Section 5.2.4) . If the concentration at the
well (i.e., point of compliance) is at or below the Drinking Water Standard, the design
may prove acceptable. Since the model response is linear with this parameter, it is
convenient to use 1.0 mg/1 as the initial concentration and to calculate a dilution-
attenuation factor (DAF) as discussed in Section 5.4.2.
6.2.7 Source Decay Constant Fl/yrl
The source decay constant is used for simulation of an exponentially decreasing (in
time) boundary condition (see Section 5.2 of Salhotra et al. , 1990). However, the
source is assumed to be constant in Subtitle D applications of MULTIMED. Therefore,
for Subtitle D applications the preprocessor sets a default value of 0 for the source
decay rate.
6.2.8 Duration of Pulse Fyrl
The duration of the contaminant pulse is not required in steady-state applications of
MULTIMED. Therefore, this parameter does not need to be estimated for Subtitle D
applications, which must be steady-state.
6.2.9 Spread of Contaminant Source [ml
The standard deviation of the gaussian source is a measure of the spread of the source.
It can be estimated or derived by the code as:
O = W/6 (6.3)
where
w = the width scale of the facility--!.e., the dimension of the facility orthogonal
to the groundwater flow direction [m]
Dividing by 6 implies that 99.86 percent of the gaussian source spread is within the
facility.
6.3 UNSATURATED FLOW PARAMETERS
6.3.1 Saturated Hydraulic Conductivity Tcm/hrl
Hydraulic conductivity expresses the ease with which a fluid can be transported through
a porous medium and is a function of properties of both the porous medium and the fluid
(Mills et al., 1985b). Note that for some materials, such as alluvium, the vertical
hydraulic conductivity is significantly smaller than the horizontal hydraulic
conductivity. Mills et al. (1985b) state that the ratio of horizontal to vertical
conductivity is from 2 to 10 for alluvium and glacial outwash and from 1.5 to 3 for
sandstone. In the unsaturated zone module, flow is one-dimensional in the vertical
direction, so the vertical hydraulic conductivity should be input. Note that in the
saturated zone, the horizontal hydraulic conductivity is required.
One of the most widely-used tables of hydraulic conductivity values is presented in
Table 6-1. Note that the use of the values in this table will require a conversion to
the units of cm/hr. In addition, descriptive statistics for a variety of soil types
are given in Table 6-2. The values for the coefficients of variation in column three
are determined from many soils nationwide which fall into each texture group. The
coefficient of variation for a single soil is likely to be lower.
The lognormal distribution is likely to be an appropriate probability density function
81
-------
for saturated hydraulic conductivity (Dean et al., 1989)
82
-------
Table 6-1 (Graphic)
83
-------
TABLE 6-2. DESCRIPTIVE STATISTICS FOR SATURATED HYDRAULIC CONDUCTIVITY
(cm hr"1)
4444444444444444444444444444444444444444444444444444444444444444444444
_ Hydraulic Conductivity (Ks)*
Soil Type x s CV n
Clay** 0.20 0.42 210.3 114
Clay Loam 0.26 0.70 267.2 345
Loam 1.04 1.82 174.6 735
Loamy Sand 14.59 11.36 77.9 315
Silt 0.25 0.33 129.9 88
Silt Loam 0.45 1.23 275.1 1093
Silty Clay 0.02 0.11 453.3 126
Silty Clay Loam 0.07 0.19 288.7 592
Sand 29.70 15.60 52.4 246
Sandy Clay 0.12 0.28 234.1 46
Sandy Clay Loam 1.31 2.74 208.6 214
Sandy Loam 4.42 5.63 127.0 1183
_
n = Sample size, x = Mean, s = Standard deviation, CV = Coefficient of
variation (percent)
Agricultural soil, less than 60 percent clay
Sources: From Dean et al . (1989),
Original reference Carsel and Parrish (1988).
6.3.2 Unsaturated Zone Porosity F--1
Porosity is a measure of the relative volume of void space in a rock or soil. Porosity
is dimensionless and is expressed as a fraction or a percentage. The total porosity
of a rock or soil is comprised of primary porosity, which is due to the shape, sorting
and packing of the grains in the matrix, and secondary porosity, which is due to
phenomena such as cracks and fractures.
MULTIMED requires the effective porosity of the rock or soil as input. The effective
porosity is that part of the total porosity which is effective at transmitting water.
The effective porosity is typically lower than the total porosity, due to the presence
of pores which are not interconnected or the
presence of an immobile water film bound to soil grains. In general, laboratory
measurements obtain values for total porosity, since effective porosity is difficult
to measure directly.
Typical total porosity values for a variety of geologic materials are presented in
Table 6-3. Jury (1985) states that a normal distribution is an appropriate probability
density function for effective porosity.
6.3.3 Air Entry Pressure Head [ml
The air entry pressure head is the threshold at which air starts to penetrate saturated
soil. It is typically a very small negative value for fine-grained materials or zero
for coarser soils. Its value can be estimated from the water retention curves of
specific soils (Freeze and Cherry, 1979) .
84
-------
6.3.4 Number of Layers, Thickness of Layers [ml
The unsaturated zone extends from the land surface or the bottom of a waste disposal
facility to the top of the water table. This distance will vary significantly from
site to site. An estimate of this depth can be determined from water level
measurements in the area of the site.
TABLE 6-3. TOTAL POROSITY OF VARIOUS MATERIALS
4444444444444444444444444444444444444444444444444444444444444444444444
No. of Arithmetic
Material Analyses Range Mean
Igneous Rocks
Weathered granite 8 0.34-0.57 0.45
Weathered gabbro 4 0.42-0.45 0.43
Basalt 94 0.03-0.35 0.17
Sedimentary Materials
Sandstone 65 0.14-0.49 0.34
Siltstone 7 0.21-0.41 0.35
Sand (fine) 243 0.26-0.53 0.43
Sand (coarse) 26 0.31-0.46 0.39
Gravel (fine) 38 0.25-0.38 0.34
Gravel (coarse) 15 0.24-0.36 0.28
Silt 281 0.34-0.61 0.46
Clay 74 0.34-0.57 0.42
Limestone 74 0.07-0.56 0.30
Metamorphic Rocks
Schist 18 0.04-0.49 0.38
Sources: From Mercer et al . (1982),
Mcwhorter and Sunada (1977) ,
Original reference Morris and Johnson, (1967).
85
-------
In MULTIMED, the unsaturated zone can be modeled with up to 20 layers which have
distinct physical characteristics. Information about the layers, which should be
relatively homogeneous and distinguishable from adjacent layers, must be determined on
a site-specific basis. Note that more than one layer can be assigned the same material
properties, when one homogeneous layer is modeled, the layer thickness is equal to the
depth of the unsaturated zone and the depth of the unsaturated zone can have a Monte
Carlo distribution assigned to it. Refer to Section 6.4.1 for more information.
6.3.5 Residual Water Content F--1
The residual water content is that amount of the total water content which can not be
removed from the soil, even under large suction pressure, because it adheres to the
soil grains. Descriptive statistics for residual water content for a variety of types
of soils are presented in Table 6-4. In addition, the residual water content for a
large number of soils can be estimated using the interactive computer program, DBAPE,
which is a soils data base analyzer and parameter estimator (Imhoff et al., 1990).
DBAPE is available from the U.S. EPA Center for Environmental Assessment Modeling
(CEAM) at the Environmental Research Laboratory in Athens, Georgia.
6.3.6 Brooks and Corey Exponent F--1
The Brooks and Corey exponent, n, is an empirical parameter used in an equation which
describes the relationship between relative permeability and water saturation (see
Section 3.2 of the MULTIMED model theory documentation (Salhotra et al., 1990)). The
exponent can be determined from experimental data for a soil's capillary pressure-
desaturation curve. Brooks and Corey (1966) present experimental results for several
porous media. The porous media investigated by the authors had values of n ranging
from 3.27 for glass beads to 4.11 for a silt loam. Soils composed of single-grained
material with no secondary porosity (e.g., sands) tend to have smaller exponent values.
Soils with structure or secondary porosity have larger exponent values.
In MULTIMED, the relationship between relative permeability and water saturation may
be described using either the Brooks and Corey (1966) or the van Genuchten (1976)
relationship (see Section 3 of Salhotra et al. (1990)). The Brooks and Corey exponent
is not required when the use of the van Genuchten relationship is specified in the
input. However, both the Brooks and Corey exponent and the van Genuchten parameters
are required when the use of the Brooks and Corey relationship is specified.
6.3.7 Van Genuchten Parameters, a Fl/cml ; B F--1
In the code, the relationship between relative permeability and water saturation may
be described using either the Brooks and Corey (1966) or the van Genuchten (1976)
relationship. However, the pressure head versus water saturation relationship is
described using van Genuchten parameters (see Section 3 of the MULTIMED model theory
documentation (Salhotra et al. , 1990)). Therefore, the van Genuchten parameters must
be input to simulate unsaturated flow in the code. Descriptive statistics for these
empirical parameters have been reported by Carsel and Parrish (1988) for a variety of
soil types (see Table 6-5) .
86
-------
TABLE 6-4. DESCRIPTIVE STATISTICS FOR SATURATION WATER CONTENT (6J
AND RESIDUAL WATER CONTENT (6r)
4444444444444444444444444444444444444444444444444444444444444444444444
Saturation Water Content (6J Residual Water Content (6r)
Statistic*
Soil Type
CV
n
CV
n
Clay"
Clay Loam
Loam
Loamy Sand
Silt
Silt Loam
Silty Clay
Silty Clay Loam
Sand
Sandy Clay
Sandy Clay Loam
Sandy Loam
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
.38
.41
.43
.41
.46
.45
.36
.43
.43
.38
.39
.41
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
.09
.09
.10
.09
. 11
.08
.07
.07
.06
.05
.07
.09
24 .
22.
22.
21.
17 .
18.
19.
17 .
15.
13.
17.
21.
. 1
.4
. 1
.6
.4
. 7
.6
.2
. 1
. 7
. 5
.0
400
364
735
315
82
1093
374
641
246
46
214
1183
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
.068
.095
.078
.057
.034
.067
.070
.089
.045
.100
.100
.065
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
.034
.010
.013
.015
.010
.015
.023
.009
.010
.013
.006
.017
49.
10.
16.
25.
29.
21.
33.
10.
22 .
12.
6.
26.
.9
. 1
. 5
. 7
.8
.6
. 5
.6
.3
.9
.0
.6
353
363
735
315
82
1093
371
641
246
46
214
1183
_
n = Sample size, x = Mean, s = standard deviation, CV = coefficient of
variation (percent)
Agricultural soil, less than 60 percent clay.
Source: Dean et al . (1989)
Original source Carsel and Parrish (1988)
6.4 UNSATURATED TRANSPORT PARAMETERS
6.4.1 Number of Layers, Thickness of Layers
The number of layers specified for transport in the unsaturated zone will depend on the
specific conditions present at the site. Layers should represent zones that are
relatively homogeneous with regard to the properties affecting transport and that can
be distinguished from adjacent layers by changes in these properties. Note that the
number and thickness of layers specified in the transport module need not correspond
to the number and thickness of layers in the unsaturated flow module (see Section
6.3.4). However, the sum of the individual layer thicknesses in the two modules must
equal each other (i.e., the total depth of the unsaturated zone must agree in the two
modules) . If the depth of the unsaturated zone is assigned a Monte Carlo distribution
in the unsaturated flow module, then only one unsaturated transport layer is allowed.
87
-------
Table 6-5. DESCRIPTIVE STATISTICS FOR VAN GENUCHTEN WATER RETENTION MODEL PARAMETERS, a, 3, and Y (Carsel and
Parrish 1988)
Parameter a.
Parameter
Soil
Claya
Clay
Loam
Loamy
Silt
Silt
Silty
Silty
Sand
Sandy
Sandy
Sandy
Type
Loam
Sand
Loam
Clay
Clay Loam
Clay
Clay Loam
Loam
X = Mean, SD = Standard
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
X
.008
.019
.036
.124
.016
.020
.005
.010
. 145
.027
.059
. 075
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
Deviation, CV =
SD
012
015
021
043
007
012
005
006
029
017
038
037
Y
cm
CV
160.
77 .
57 .
35.
45 .
64.
113.
61.
20.
61.
64.
49.
.3
.9
. 1
.2
.0
. 7
.6
. 5
.3
. 7
.6
.4
Coefficient
-i
N
400
363
735
315
88
1093
126
641
246
46
214
1183
Parameter
1.
1.
1.
2.
1.
1.
1.
1.
2.
1.
1.
1.
of Variation
X
.09
.31
.56
.28
.37
.41
.09
.23
.68
.23
.48
.89
SD
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
.09
.09
.11
.27
.05
.12
.06
.06
.29
.10
.13
. 17
(percent) ,
CV
7.9
7.2
7.3
12.0
3.3
8.5
5.0
5.0
20.3
7.9
8.7
9.2
N =
N
400
364
735
315
88
1093
374
641
246
46
214
1183
Sample
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
size
3
X
08
24
36
56
27
29
09
19
62
18
32
47
SD
0.07
0.06
0.05
0.04
0.02
0.06
0.05
0.04
0.04
0.06
0.06
0.05
CV
82.
23.
13.
7 .
8.
19.
51.
21.
6.
34.
53.
10.
. 7
. 5
. 5
. 7
.6
.9
. 7
. 5
.3
. 7
.0
.1
N
400
364
735
315
88
1093
374
641
246
46
214
1183
Agricultural Soil, Clay 60 percent
-------
6.4.2 Longitudinal Dispersivity of Each Layer [ml
Hydrodynamic dispersion refers to the spreading and mixing caused by molecular
diffusion and mechanical dispersion (Freeze and Cherry, 1979). For many field
problems, molecular diffusion is small relative to mechanical dispersion and can be
ignored. Molecular diffusion is not considered in MULTIMED, which calculates the
longitudinal dispersion coefficient as the product of the seepage velocity and
longitudinal (aL) dispersivity. Note that longitudinal dispersion is the dispersion
in the predominant direction of flow, which is vertical in the unsaturated zone.
Dispersivity is a difficult parameter to determine. Table 6-6 provides a compilation
of dispersivity values appropriate for the unsaturated transport module. Research
has shown that the values for longitudinal dispersivity are scale dependent. In an
unsaturated transport layer, if a value for the longitudinal dispersivity is not
input, the user can specify that the parameter be derived. The equation used in the
model to calculate dispersivity is based on regression analysis of the data in Table
6-6. The following relationship between dispersivity and the depth of the
unsaturated zone, L, was developed:
av = 0.02 +0.022L, R2 = 66% (6.4)
To avoid excessively high values of dispersivity for deep unsaturated zones, a
maximum dispersivity of 1.0 m is used.
Distributional properties for longitudinal dispersivity are unknown (Dean et al.,
1989) .
6.4.3 Percent Organic Matter [--1
Guidance in estimating the percent organic matter is provided in Table 6-7. Values
are given for the four Hydrologic Soil Groups and for four ranges of depth. From
Appendix B of the users manual for PRZM, Release I (Carsel et al., 1984) or from
Section 4 of the SCS National Engineering Handbook (Soil Conservation Service, 1972),
the hydrologic soil group for the particular soil that is in the area under
consideration can be found. There are four different soil classifications (A, B, C,
and D) , and they are in the order of decreasing percolation potential and increasing
slope and runoff potential. Soil characteristics associated with each hydrologic
group are as follows:
Group A: Deep sand, deep loess, aggregated silts, minimum infiltration of
0.76 - 1.14 (cm hr"1)
Group B: Shallow loess, sandy loam, minimum infiltration 0.38 - 0.76 (cm
hr-1)
Group C: Clay loams, shallow sandy loam, soils low in organic content, and
soils usually high in clay, minimum infiltration 0.13 - 0.38 (cm
hr-1)
Group D: Soils that swell significantly when wet, heavy plastic clays, some
saline soils, minimum infiltration 0.03 - 0.13 (cm hr"1)
89
-------
TABLE 6-6. COMPILATION OF FIELD DISPERSIVITY VALUES
44444444444444444444444444444444444444444444444444444444444444444444444
(1976)
Longitudinal
Author
Yule and Gardner
(1978)
Hildebrand and
Himmelblau (1977)
Kirda et al .
(1973)
Gaudet et al .
(1977)
Brissaud et al .
(1983)
Warrick et al .
(1971)
Van de Pol et al .
(1977)
Biggar and Nielsen
Type of Vertical Scale Dispersivity
Experiment of Experiment (m) av (m)
Laboratory
Laboratory
Laboratory
Laboratory
Field
Field
Field
Field
0.23
0.79
0.60
0.94
1.00
1.20
1.50
1.83
0.0022
0.0018
0.004
0.01
0.0011,
0.002
0.027
0 . 0941
0.05
Kies (1981)
Jury et al . (1982)
Andersen et al .
(1968)
Oakes (1977)
Field
Field
Field
Field
2.00
2.00
20.00
20.00
0.168
0 . 0945
0.70
0.20
From Dean et al. (1989),
Original reference Gelhar et al. (1985).
90
-------
TABLE 6-7. DESCRIPTIVE STATISTICS AND DISTRIBUTION MODEL FOR ORGANIC
MATTER (PERCENT BY WEIGHT)
44444444444444444444444444444444444444444444444444444444444444444444444
Stratum
(m)
Class A
0.0-0.3
0.3-0.6
0.6-0.9
0.9-1.2
Class B
0.0-0.3
0.3-0.6
0.6-0.9
0.9-1.2
Class C
0.0-0.3
0.3-0.6
0.3-0.9
0.9-1.2
Class D
0.0-0.3
0.3-0.6
0.6-0.9
0.9-1.2
Sample
Size
162
162
151
134
1135
1120
1090
1001
838
822
780
672
638
617
558
493
Original Data
Mean
)))))))))))
0
0
0
0
0
0
0
1
0
0
0
1
0
0
0
.86
.29
.15
.11
1.3
.50
.27
.18
.45
.53
.28
.20
.34
.65
.41
.29
Median
')))))))))))}
0
0
0
0
0
0
0
1
0
0
0
1
0
0
0
.62
.19
.10
.07
1. 1
.40
.22
. 14
.15
.39
.22
. 15
.15
.53
.32
.22
s .
1)))))
0.
0.
0.
0.
0.
0.
0.
0.
1.
0.
0.
0.
0.
0.
0.
0.
.d.
))))))]
.79
.34
. 14
.11
.87
.40
.23
.16
. 12
.61
.27
.21
.87
.52
.34
.31
CV
(%)
))))))))))
92
114
94
104
68
83
84
87
77
114
96
104
66
80
84
105
Distribution Model
Mean
-4 .
-5 .
-6.
-6.
-4 .
-5 .
-5.
-6.
-3.
-5 .
-5.
-6.
-4 .
-4 .
-5.
-5 .
.53
.72
.33
.72
.02
.04
.65
.10
.95
.08
.67
.03
.01
.79
.29
.65
S .
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
.d.
.96
.91
.83
.87
.76
. 77
.75
.78
.79
.84
.83
.88
.73
.78
.82
.86
CV = coefficient of variation
s.d. = standard deviation
Source: Dean et al. (1989), Original reference Carsel et al. (1988;
a Johnson SB transformation is used for all cases in this table.
91
-------
Carsel et al. (1988) state that a Johnson SB distribution is most appropriate for the
data in Table 6-7. Note that the percent organic matter typically decreases with
depth. More detailed data on percent organic matter are available through the
interactive computer program DBAPE discussed in Section 6.3.5 (Imhoff et al., 1990).
If the percent organic matter is not known, but the fractional organic carbon content
is given, the following equation can be used to estimate the percent organic matter:
fom = 172.4 foc (6.5)
where
foc = fractional organic carbon content [dimensionless]
fom = percent organic matter [dimensionless]
172.4 = conversion factor from percent organic matter content to
fractional organic carbon content
6.4.4 Bulk Density of Soil for Layer [g/ccl
Bulk density can be defined as the mass of a unit volume of dry soil (Mercer et al.,
1982). The soil bulk density directly influences the retardation of solutes and is
related to the structure and texture of a soil. The bulk density of soils typically
range between 1.3 and 2.0 g/cc, but Mercer et al. (1982) state that the bulk density
can be as low as 0.3 g/cc for soils high in organics or aluminum and iron hydroxides.
Representative values for five different types of soils are shown in Table 6-8. In
addition, values of bulk density for a large number of soils can be obtained from
DBAPE, discussed in Section 6.3.5 (Imhoff et al., 1990).
Descriptive statistics for bulk density are given in Table 6-9 for the four
Hydrologic Soil Groups (A, B, C, and D) and for four ranges of depth. (A brief
description of the soil groups in given in Section 6.4.3.) The most appropriate
probability density distribution for bulk density is typically a normal distribution
(Jury, 1985) .
6.4.5 Biological Decay Coefficient n/yrl
Estimation of the biodegradation rate constant is discussed in Section 6.1.7.
6.5 AQUIFER-SPECIFIC PARAMETERS
6.5.1 Aquifer Porosity F--1
Porosity is also discussed in Section 6.5.1 and values of porosity for various
materials are given in Table 6-3. It is an important parameter, influencing the
velocity and retardation of contaminants transported in an aquifer (Mills et al. ,
1985b). In the absence of a user-specified distribution for the aquifer porosity, it
can be derived by the code. It is calculated from the particle diameter using the
following empirical relationship (Federal Register Vol. 51, No. 9, p. 1649, 1986):
92
-------
TABLE 6-8. MEAN BULK DENSITY (g/cm3) FOR FIVE SOIL TEXTURAL
CLASSIFICATIONS3'1"
44444444444444444444444444444444444444444444444444444444444444444444444
Soil Texture Mean Value Range Reported
)))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))
Silt Loams 1.32 0.86 - 1.67
Clay and Clay Loams 1.30 0.94-1.54
Sandy Loams 1.49 1.25-1.76
Gravelly Silt Loams 1.22 1.02-1.58
Loams 1.42 1.16-1.58
All Soils 1.35 0.86 - 1.76
Baes, C.F., III and R.D. Sharp. 1983. A Proposal for Estimation of
Soil Leaching Constants for Use in Assessment Models. J. Environ.
Qual. 12(1): 17-28 (Original reference).
From Dean et al . (1989)
6 = 0.261 - 0.0385 In (d) (6.6)
where d is the mean particle diameter [cm] .
6.5.2 Particle Diameter Fcrnl
The particle diameter can be determined by methods such as sieve analysis (Freeze and
Cherry, 1979) . Table 6-10 shows the range of soil particle sizes for a variety of
soil materials. If the porosity is known, the particle diameter can be derived using
Equation 6.6. Note that both porosity and particle diameter can not be derived in
the same simulation (i.e., at least one must be input by the user).
6.5.3 Bulk Density Fg/ccl
Bulk density is discussed in Section 6.4.4 and Tables 6-8 and 6-9 provide data on the
bulk density of soils. However, the bulk density of aquifer materials may differ
significantly from that of soils. Therefore, data on the ranges of bulk density for
various geologic material are presented in Table 6-11.
If site-specific data are not available, the bulk density of the saturated zone can
be derived by the model using an exact relationship between porosity, particle
density and the bulk density (Freeze and Cherry, 1979) . Assuming the particle
density to be 2.65 g/cc, this relationship can be expressed as:
93
-------
Table 6-9. DESCRIPTIVE STATISTICS FOR BULK DENSITY (g cm"3)
44444444444444444444444444444444444444444444444444444444444444444444444
Stratum Sample
(m) Size Mean Median s.d.
Class A
CV
(%)
0.0-0.3
0.3-0.6
0.6-0.9
0.9-1.2
40
44
38
34
1.45
1.50
1.57
1.58
1.53
1.56
1.55
1.59
0 .24
0.23
0.16
0.13
16.2
15.6
10.5
8.4
Class B
0.0-0.3
0.3-0.6
0.6-0.9
0.9-1.2
459
457
438
384
1.44
1.51
1.56
1.60
1.45
1.53
1. 57
1.60
0.19
0.19
0.19
0.21
13.5
12 .2
12.3
12 . 9
Class C
0.0-0.3
0.3-0.6
0.6-0.9
0.9-1.2
398
395
371
326
1.46
1.58
1. 64
1.67
1.48
1.59
1.65
1.68
0 .22
0.23
0.23
0.23
15.0
14 . 5
14 .2
14 . 0
Class D
0.0-0.3
0.3-0.6
0.6-0.9
0.9-1.2
259
244
214
180
1.52
1.63
1.67
1.65
1.53
1.66
1.72
1. 72
0.24
0.26
0.27
0.28
15.9
16.0
16.3
17.0
CV = coefficient of variation
s.d. = standard deviation
Sources: From Dean et al . (1989),
Original reference Carsel et al . (1988)
94
-------
TABLE 6-10. RANGE OF SOIL PARTICLE SIZES FOR VARIOUS MATERIALS
44444444444444444444444444444444444444444444444444444444444444444444444
Size Range Approximate Sieve Mesh
Openings
Class name
Millimeters
Inches
Tyler United States Standard
Very large boulders 4,096-2,048
Large boulders
Medium boulders
Small boulders
Large cobbles
Small cobbles
Very coarse gravel
Coarse gravel
Medium gravel
Fine gravel
Very fine gravel
Very coarse sand
Coarse sand
Medium sand
Fine sand
Very fine sand
Coarse silt
Medium silt
Fine silt
Very fine silt
Coarse clay
Medium clay
Fine clay
Very fine clay
2,048-1,024
1,024-512
512-256
256-128
128-64
64-32
32-16
16-8
8-4
4-2
2.000-1.000
1.000-0.500
0.500-0.250
0.250-0.125
0.125-0.062
0.062-0.031
0.031-0.016
0.016-0.008
0.008-0.004
0.004-0.0020
0.0020-0.0010
0.0010-0.0005
0.0005-0.00024
Modified from Vanoni (1975).
160-80
80-40
40-20
20-10
10-5
5-2.5
2.5-1.3
1.3-0.6
0.6-0.3
0.3-0.16
0.16-0.08
2-1/2
5
16
32
60
115
250
5
10
18
35
60
120
230
Reference:
pb = 2.65 (1 - 6) (6.7)
where pb = the bulk density of the soil [g/cc].
6.5.4 Aquifer Thickness [ml
The estimation of the thickness of the aquifer is site-specific, and should be based
on available geologic data.
6.5.5 Source Thickness (Mixing Zone Depth) [ml
Percolation of water through the facility (and unsaturated zone, if it exists)
results in the development of a contaminant plume below the facility (see Figure
6.1). The thickness, H, of this plume depends on the vertical dispersivity of the
media. If a value for H is not known, it can be derived in the model using the
following relationship:
95
-------
TABLE 6-11. RANGE AND MEAN VALUES OF DRY BULK DENSITY FOR VARIOUS GEOLOGIC
MATERIALS
4444444444444444444444444444444444444444444444444444444444444444444444444444
Material Range (g/cm3) Mean (g/cm3)
Clay
Silt
Sand, fine
Sand, medium
Sand, coarse
Gravel, fine
Gravel, medium
Gravel, coarse
Loess
Eolian sand
Till, predominantly silt
Till, predominantly sand
Till, predominantly gravel
Glacial drift, predominantly silt
Glacial drift, predominantly sand
Glacial drift, predominantly gravel
Sandstone, fine grained
Sandstone, medium grained
Siltstone
Claystone
Shale
Limestone
Dolomite
Granite, weathered
Gabbro, weathered
Basalt
Schist
Reference: Morris and Johnson (1967)
1.
1.
1.
1.
1.
1.
1.
1.
1.
1.
1.
1.
1.
1.
1.
1.
1.
1.
1.
1.
2 .
1.
1.
1.
1.
1.
1.
.18
.01
.13
.27
.42
.60
.47
.69
.25
.33
.61
.69
. 72
. 11
.36
.47
.34
.50
.35
.37
.20
.21
.83
.21
.67
.99
.42
; Mills
-1.
-1.
-1.
-1.
-1.
-1.
-2.
-2.
-1.
-1.
-1.
-2.
-2 .
-1.
-1.
-1.
-2 .
-1.
-2.
-1.
-2 .
-2 .
-2.
-1.
-1.
-2 .
-2.
et
72
79
99
93
94
99
09
08
62
70
91
12
12
66
83
78
32
86
12
60
72
69
20
78
77
89
69
al.
1.
1.
1.
1.
1.
1.
1.
1.
1.
1.
1.
1.
1.
1.
1.
1.
1.
1.
1.
1.
2 .
1.
2.
1.
1.
2 .
1.
(1985b)
.49
.38
. 55
.69
.73
.76
.85
.93
.45
.58
.78
.88
.91
.38
. 55
.60
.76
.68
.61
.51
.53
.94
.02
.50
.73
.53
.76
-------
Figure 6 .1
97
-------
H = (2av
+ B(l - exp
(6.8)
where
av = the vertical dispersivity [m]
L = the length scale of the facility--!.e., the dimension of the facility
parallel to the flow direction [m] (if L is not known, an estimate can
be obtained from Equation 6.2)
B = the thickness of the saturated zone [m]
Vs = one-dimensional, uniform seepage velocity in the x direction [m/yr]
Qf = percolation rate [m/yr]
In Equation 6.8 the first term represents the thickness of the plume due to vertical
dispersion and the second term represents the thickness of the plume due to the
vertical velocity below the facility resulting from percolation. While implementing
this alternative, the code checks that the computed value of the thickness of the
source, H, is not greater than the thickness of the aquifer, B. If it is, the source
thickness is set equal to the aquifer thickness.
6.5.6 Hydraulic Conductivity Tm/yrl
Hydraulic conductivity estimates should be based on site-specific data collection,
such as piezometer tests (bail tests or slug tests) and/or pumping tests. Some
typical hydraulic conductivity values for various materials are shown in Tables 6-1
and 6-2 and discussed in Section 6.3.1. Note that the units of hydraulic
conductivity are m/yr in the saturated zone, but cm/hr elsewhere in the code.
An alternative, though often a poor one, is to allow the code to derive a value for
hydraulic conductivity. The code uses an approximate functional relationship, the
Kozeny-Carman equation (Bear 1979) :
K =
(6.9)
where
K = the hydraulic conductivity [cm/s]
p = the density of water [kg/m3]
g = acceleration due to gravity [m/s2]
u = the dynamic viscosity of water [N-s/m2]
d = mean particle diameter [cm]
In Equation 6.9, the constant 1.8 includes a unit conversion factor. Both the
density of water, p, and the dynamic viscosity of water, u, are functions of
temperature and are computed using regression equations presented in CRC (1981)
Note that at 15°C, the value of [pg/1.8u] is about 478.
98
-------
6.5.7 Hydraulic Gradient I'm/ml
The hydraulic gradient is the change in water level elevation over a given distance.
In general, it is a function of the local topography, groundwater recharge volume and
location, and the volume and location of groundwater withdrawals. Further, it may
also be related to the porous media properties.
The gradient can often be estimated from water level measurements in the area
surrounding the site or from a map of water table or potentiometric surface
elevations. The average gradient under natural conditions should be input in the
model. Therefore estimates should not include the effect of pumping. The data used
to estimate the hydraulic gradient can also be used to determine the direction of
groundwater flow.
6.5.
Groundwater Seepage Velocity Tm/vrl
The groundwater velocity is needed to quantify transport by advection. Because
groundwater velocities are difficult to measure directly, they are often determined
indirectly, using the fact that seepage velocity is related to the aquifer properties
through Darcy's Law. Assuming a uniform, saturated porous medium, the seepage
velocity can be expressed as:
vs = KS/6 (6.10)
where
K = the hydraulic conductivity of the formation [m/yr]
S = the hydraulic gradient [m/m]
MULTIMED allows the user to derive the seepage velocity by means of Equation 6.10
instead of directly entering a value.
Note that the hydraulic conductivity of the aquifer is used by the code only to
calculate the seepage velocity. Therefore, if the groundwater seepage velocity is
specified by the user, the hydraulic conductivity will not be used.
6.5.
Retardation Coefficient F--1
The retardation factor is used to determine the retardation, due to adsorption, of a
contaminant relative to the bulk mass of water transporting the contaminant (Freeze
and Cherry, 1979). In addition to delaying the arrival time of a contaminant at a
receptor, retardation together with dispersion can lower the peak concentration. In
MULTIMED, the retardation factor can be input directly or derived by the code using:
(6.11)
where
pb = bulk density [g/cc]
K = contaminant distribution coefficient [cc/g]
6 = saturation water content [--]
Estimation of the bulk density, distribution coefficient, and saturation water
content has been discussed in earlier sections. Note that a value of one for the
retardation coefficient means that the contaminant does not interact with the solid
phase, but acts as a conservative tracer. An example of a conservative tracer is
chloride.
99
-------
6.5.10 Longitudinal, Transverse and Vertical Dispersivities [ml
The aquifer longitudinal (aL) , transverse (aT), and vertical (av) dispersivities are
used in the model to calculate hydrodynamic dispersion (i.e., the spreading and
mixing caused by mechanical dispersion). The spreading of a contaminant caused by
molecular diffusion is assumed to be small relative to mechanical dispersion and is
ignored in the model. The estimation of longitudinal dispersivity in the unsaturated
zone is discussed in Section 6.4.2. Note that the longitudinal dispersivity is
oriented in the vertical direction for the unsaturated zone, while it is oriented in
the horizontal direction for the saturated zone.
The values for dispersivity are difficult to determine. Research has shown that the
values for these parameters are strongly scale dependent (EPRI, 1985). This can be
seen in Figure 6.2. In general, dispersion is determined by adjusting the
dispersivity values until modeling results match historical data (Mercer et al.,
1982) .
In the absence of user-specified values, the model allows two alternatives for
deriving the aquifer dispersivities. Alternative one is based on values presented in
Gelhar and Axness (1981). Dispersivities are calculated as a fraction of the
distance to the downgradient receptor well, as follows:
«L = 0 .1 xr (6.12)
aT = aL/3.0 (6.13)
av = 0.056aL (6.14)
where xr is the distance to the receptor well [m]. This option is summarized in
Table 6-12(a).
Alternative two allows a probabilistic formulation for the longitudinal dispersivity
as shown in Tables 6-12 (a) and 6-12 (b) [Gelhar (personal communication), 1986] . The
longitudinal dispersivity is assumed to be uniform within each of the three intervals
shown in Table 6-12(b). Note that these values of longitudinal dispersivity shown
are based on a receptor well distance of 152.4 m. For other distances, the following
equation is used:
«L(xr) = «L(xr = 152.4) (xr/152.4)0'5 (6.15)
The transverse and vertical dispersivity are assumed to have the following values:
100
-------
Figure 6.2
101
-------
TABLE 6-12(a). ALTERNATIVES FOR INCLUDING DISPERSIVITIES IN THE
SATURATED ZONE MODULE
4444444444444444444444444444444444444444444444444444444444444444444444444444
Dispersivitv
Alternative 1 Alternative 2
Existing Values Gelhar's Recommendation
«L [m]
Formulation
«T [m]
av [m]
aL/aT
aL/av
0 . 1 xr Probabilistic
(See Table 5-3 (b) )
0.333 «L Oij8
0.056 «L «L/160
3 8
approx. 18 160
TABLE 6-12(b). PROBABILISTIC REPRESENTATION OF LONGITUDINAL DISPERSIVITY
FOR A DISTANCE OF 152.4 m
4444444444444444444444444444444444444444444444444444444444444444444444444444
«L (m) 0.1-1
Probability 0.1
Cumulative 0.1
Probability
1-10
0.6
0.7
10-100
0.3
1.0
102
-------
«T = aL/8 (6.16)
av = aL/l60 (6.17)
The distributional properties for the longitudinal and transverse dispersivities are
unknown (Dean et al., 1989).
6.5.11 Aquifer Temperature r°C1
This parameter is site-specific and should be measured at the site. Note that
MULTIMED does not take into account any seasonal variation in temperature in the
uppermost portions of the aquifer. Instead, an average value should be used. The
average temperature of shallow groundwater in the United States is shown in Figure
6.3.
6.5.12 pH TpH unitsi
The pH values of groundwater in the United States typically range between 6.0 and
8.5. However, values as high as 11.0 for alkali-spring water and as low as 1.8 for
acid hot-spring water have been determined (Mercer et al., 1982). The pH can be
measured from groundwater samples in the field. For some aquifers, data may be
available from the U.S. Geological Survey, the U.S. Environmental Protection Agency,
or from state and local agencies.
6.5.13 Organic Carbon Content (Fraction) [--1
The fractional organic carbon content can be estimated from the percent organic
matter by the following relationship:
foc = fom/172.4 (6.18)
where
foc = fractional organic carbon content [dimensionless]
fom = percent organic matter [dimensionless]
172.4 = conversion factor from percent organic matter content to
fractional organic carbon content
Information about the percent organic matter in soils is provided in Section 6.4.3.
Typically the value of the percent organic matter (and hence, the fractional organic
carbon content) is smaller for an aquifer than for near-surface soils.
6.5.14 Well Distance from Site [ml , Angle off Center [degrees! , and Well
Vertical Distance [ml
A schematic of the receptor well location relative to the waste facility was
presented in Figure 6.1. The location of the well is determined by specifying the
radial distance to the well, the angle between the plume centerline and the radial
location of the well measured counterclockwise and the depth of penetration of the
well. The well screen depth is specified as the fraction (i.e., a value between 0
and 1) of the total aquifer thickness and is measured downward from the water table.
The well is assumed to have a single opening at the depth specified. The code uses
the input to calculate the cartesian coordinates of the well location as discussed in
Section 5.2.3.
For Subtitle D applications of the model, a conservative approach is required. Thus,
the well is assumed to be located on the contaminant plume centerline (i.e., the
angle off center is fixed at zero degrees) and the well vertical distance is also
fixed at zero (i.e., the contaminant concentration is predicted at the water table).
103
-------
Figure 6.3
104
-------
SECTION 7
EXAMPLE PROBLEMS
Three example problems are presented in this section. These problems are designed to
demonstrate the application of MULTIMED to a variety of scenarios which might be
encountered while studying Subtitle D facilities. Example 1 is a deterministic,
steady-state simulation of transport in the saturated zone. The second example is
identical to Example 1, but includes flow and transport in the unsaturated zone.
This example is included in the deterministic tutorial for the preprocessor, PREMED,
and can be accessed from the opening screen of the preprocessor by typing
<@DETER.LOG> (do not type the brackets). Example 3 is similar to Example 2, but it
is run in Monte-Carlo mode. This example is the same as the input generated by the
Monte Carlo tutorial, which is accessed from the preprocessor opening screen by
typing <@MONTE.LOG>.
Because new versions of the MULTIMED code may be released after the publication of
this document, the results presented in this section may differ from the result
obtained from using the input generated by the tutorials. Therefore, these examples
should not be viewed as validation data sets. Input and output for model validation
are distributed with the code.
Note that the scenarios represented by these simulations are hypothetical, and are
not intended to resemble any actual sites. The values used in these example problems
are not EPA-recommended values for use in MULTIMED.
7.1 EXAMPLE 1
7.1.1 The Hypothetical Scenario
A well which supplies drinking water to a small community is located 152 meters
directly downgradient from a waste disposal facility. The members of the community
want to predict the effect of the waste disposal facility on the water quality in the
well.
The bottom of the waste disposal facility is located just above the water table.
Therefore, simulation of flow and transport in the unsaturated zone is unnecessary,
and only saturated transport is simulated.
One contaminant has been selected by the community for simulation, based on its
unusual persistence in the subsurface environment. This contaminant is not
biodegradable, and has an overall chemical decay coefficient which is so small it can
be assumed to be zero (this is a conservative approach). The normalized
106
-------
distribution coefficient for the contaminant is also assumed to be zero, so the
chemical will not be removed from the groundwater by the process of adsorption.
For convenience in calculating the dilution attenuation factor (DAF), discussed in
Section 5.2.4, the concentration of the contaminant at the bottom of the facility is
assumed to be 1.00 mg/1. This source concentration is constant in time. The area of
the waste disposal site is approximately 400 m2 and it is square in shape. The
infiltration rate into the aquifer beneath the facility is .007 m/yr, and the
recharge rate into the aquifer downgradient of the facility is slightly higher at
.0076 m/yr. No temporal variability in these rates has been observed.
The aquifer is 78.6 meters thick and the hydraulic gradient within the aquifer is
constant at 0.0306. The estimated longitudinal dispersivity in the aquifer is 160 m,
the transverse dispersivity is 15.2 m and the vertical dispersivity is 8 m. The
fraction of organic carbon in the aquifer is .00315. The pH of the groundwater in
the aquifer is typical of many groundwaters in the United States and has been
measured to be 6.20. The average annual temperature in the aquifer is 14.4 °C.
The lack of temporal variability in this system indicates that a steady-state
simulation is appropriate. Furthermore, the values of the parameters are known with
a high degree of certainty, so a deterministic simulation was selected.
7.1.2 Input
MULTIMED input for Example 1 is shown in Table 7-1. It consists of the title for the
Example 1 simulation, followed by several data groups. The values assigned to
specific parameters are clearly labeled for all of the data groups except the General
data group. The parameters in the General Data Group and the format of the entire
input sequence are discussed in Appendix A.
Since only the saturated transport module is used in this example, the General Data
Group is followed by three data groups: the Chemical, Source and Aquifer Specific
Variable Data. In these data groups, the name of the input parameter and the units
for the parameter are in the left hand column. The values listed under
"Distribution" indicate whether the parameter is to be derived from other parameters
(-1 or -2) or read from the input sequence (0). Since this is a deterministic
simulation, only the values listed in the "Mean" column will be used by the model
(the standard deviation, and the minimum and maximum limits are applicable only in a
Monte Carlo simulation).
All of the Chemical Specific Parameters used by MULTIMED are listed in the input
file. However, not all of these parameters are used in the Example 1 simulation. A
discussion of which parameters are required by the saturated zone transport module
can be found in Section 5.3. To avoid obtaining values for unnecessary parameters
when developing an input sequence for MULTIMED, refer to Section 5.3, which discusses
the parameters required for specific modules, and Section 6, which discusses the
estimation and/or derivation of these parameters.
Values for some parameters may be listed as -999. These parameters are undefined.
Files generated by the preprocessor list some of the parameters which are not used by
the code as -999. PREMED will check that all of the necessary values for a
particular simulation have been defined before saving an input file. If a value of -
999 appears in the input sequence for a parameter which is required by the code, this
parameter will be listed as "Undefined", and must be specified to complete the input
sequence for use in MULTIMED. The specification of "Undefined" parameters is clearly
demonstrated in the PREMED tutorials.
107
-------
TABLE 7-1. INPUT SEQUENCE FOR EXAMPLE 1.
Example 1.
Test input sequence for MULTIMED.
GENERAL DATA
*** CHEMICAL NAME FORMAT(8OA1)
DEFAULT CHEMICAL
*** ISOURC
***OPTION OPTAIR RUN
100 DETERMINISTIC
ROUTE NT IYCHK PALPH APPTYP
MONTE ISTEAD IOPEN IZCHK LANDF COMPLETE
1 1 1 1 0 0 090.0 0 2 1
*** XST
END GENERAL
CHEMICAL SPECIFIC VARIABLE DATA
ARRAY VALUES
*** CHEMICAL SPECIFIC VARIABLES
*** VARIABLE NAME UNITS
* * *
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
Solid phase decay coeff (1/yr)
Diss phase decay coeff (1/yr)
Overall chem dcy coeff (1/yr)
Acid cataly hydrol rte(l/M-yr)
Neutral hydrol rate cons (1/yr)
Base cataly hydrol rte(l/M-yr)
Reference temperature (C)
Normalized distrib coeff (ml/g)
Distribution coefficient
Biodegrad coef (sat zone) (1/yr)
Air diffusion coeff (cm2/s)
Ref temp for air diffusion (C)
Molecular weight (g/mole)
Mole fraction of solute
Solute vapor pressure (mm Hg)
Henry's law cons (atm-m^3/M)
Not in use
Not in use
Not in use
MEAN
-1
-1
-1
0
0
0
0
0
-2
0
0
0
0
0
0
0
0
0
0
DISTRIBUTION
STD DEV
0
0
0
0
0
0
.OOOE+
.OOOE+
.OOOE+
.OOOE+
.OOOE+
.OOOE+
00
00
00
00
00
00
25.0
0
0
0
0
0
-
-
-
-
1
1
1
.OOOE+
.219
.OOOE+
.OOOE+
.OOOE+
999.
999.
999.
999.
.00
.00
.00
00
00
00
00
PARAMETERS LIMITS
MIN MAX
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.645E-02
.OOOE+00
.OOOE+00
.100E-01
.230E-01
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
0 .
0 .
0 .
0 .
0 .
0 .
0 .
0 .
0 .
0 .
0 .
0 .
0 .
0 .
0 .
0 .
0 .
0 .
0 .
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.100E-08
.OOOE+00
.100E-09
.OOOE+00
.OOOE+00
.OOOE+00
0 .100E+11
0 .100E+
11
0 .100E+11
-999.
-999.
-999.
100 .
-999.
0 .100E+11
-999.
10 .0
100 .
-999.
1.00
100 .
1.00
1.00
1.00
1.00
END ARRAY
END CHEMICAL SPECIFIC VARIABLE DATA
(continued)
108
-------
TABLE 7-1. INPUT SEQUENCE FOR EXAMPLE 1 (concluded)
SOURCE SPECIFIC VARIABLE DATA
ARRAY VALUES
*** SOURCE SPECIFIC VARIABLES
VARIABLE NAME
UNITS
DISTRIBUTION
PARAMETERS
MEAN STD DEV
LIMITS
MIN MAX
1
2
3
4
5
6
7
8
9
Infiltration rate (m/yr)
Area of waste disp unit (m^2)
Duration of pulse (yr)
Spread of contaminant srce (m)
Recharge rate (m/yr)
Source decay constant (1/yr)
Init cone at landfill (mg/1)
Length scale of facility (m)
Width scale of facility (m)
0
0
0
-1
0
0
0
-1
-1
0
-
-
0
0
-
-
.700E-02
400 .
999.
999.
.760E-02
.OOOE+00
1.00
999.
999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
0
0
0
0
0
0
0
0
0
.100E-09
.100E-01
.100E-08
.100E-08
.100E-09
.OOOE+00
.OOOE+00
.100E-08
.100E-08
0
-
-
0
0
-
-
0
0
.100E+11
999.
999.
.100E+11
.100E+11
999.
999.
.100E+11
.100E+11
END ARRAY
END SOURCE SPECIFIC VARIABLE DATA
AQUIFER SPECIFIC VARIABLE DATA
ARRAY VALUES
*** AQUIFER SPECIFIC VARIABLES
*** VARIABLE NAME UNITS
* * *
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
Particle diameter (cm)
Aquifer porosity
Bulk density (g/cc)
Aquifer thickness (m)
Mixing zone depth (m)
Hydraulic conductivity (m/yr)
Hydraulic Gradient
Grndwater seep velocity (m/yr)
Retardation coefficient
Longitudinal dispersivity (m)
Transverse dispersivity (m)
Vertical dispersivity (m)
Temperature of aquifer (C)
pH
Organic carbon content (fract)
Receptor distance from site(m)
Angle off center (degree)
Well vert dist from water tabl
DISTRIBUTION PARAMETERS
MEAN STD DEV
0
-2
-2
0
-1
-2
0
-2
-1
0
0
0
0
0
0
0
0
0
0 .630E-03
-999.
-999.
78 .6
-999.
-999.
0 .306E-01
-999.
-999.
160 .
15.2
8 .00
14 .4
6 .20
0 .315E-02
152 .
0 .OOOE+00
0 .OOOE+00
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
LIMITS
MIN MAX
.100E-08
.100E-08
.100E-01
.100E-08
.100E-08
.100E-06
.100E-07
.100E-09
1.00
.100E-02
.100E-02
.100E-02
.OOOE+00
.300
.100E-05
1.00
.OOOE+00
.OOOE+00
0
0
0
0
-
0
0
0
0
0
-
100 .
.990
5.00
.100EH
-06
.100E+06
.100EH
999.
.100EH
-09
-09
.100E+09
.100EH
-05
.100E+05
.100EH
100 .
14 .0
1.00
999.
360 .
1.00
-05
END ARRAY
END AQUIFER SPECIFIC VARIABLE DATA
END ALL DATA
109
-------
7.1.3 Output
The output for example 1 consists the main output file, the SAT.OUT file, and
files with a *.VAR extension, which are not shown. For deterministic
simulations, the *.VAR files echo the values of the constant parameters and list
the values calculated by the code for the derived parameters. Table 7-2
presents the main output file, which consists of an echo of the input and the
predicted contaminant concentration at the well. The SAT.OUT file, shown in
Table 7-3, lists the predicted contaminant concentration at the well.
7.2 EXAMPLE 2
7.2.1 The Hypothetical Scenario
The second example is identical to the first with one exception: the water table
is located at a depth of 6.1 meters below the bottom of the waste disposal
facility. Therefore, unsaturated flow and transport must also be simulated.
In this example, the unsaturated zone consists of one homogeneous layer with the
following known values for material and transport properties. The saturated
hydraulic conductivity is .017 cm/hr, the porosity is 0.43 and the bulk density
is 1.67 g/cm3. The percent organic matter is 0.026 and the Brooks and Corey
exponent is 0.5. The van Genuchten parameters, a and 3, which describe the
relationship between the pressure head and water saturation, are .009 and 1.23,
respectively. The residual water content is .088 and the longitudinal
dispersivity is .4 m.
7.2.2 Input
The chemical, source, and aquifer specific parameters are the same as those
described in Example 1. However, simulation of the unsaturated zone requires
additional data groups in the input file including soil moisture parameters and
unsaturated zone transport parameters. The input for Example 2 is shown in Table
7-4 .
7.2.3 Output
The output for Example 2 is similar to that described for Example 1. In addition
to the main output file, shown in Table 7-5, the SAT.OUT file, presented in Table
7-6, and the *.VAR files, two additional files, VFLOW.OUT and VTRNSPT.OUT, are
created. VFLOW.OUT contains output for the Unsaturated Zone Flow Module,
including the depth of each node and the Darcy velocity, water saturation, and
head at each node. (Note that the number and location of nodes is determined by
the MULTIMED code.) VTRNSPT.OUT lists the steady-state concentration at the
water table.
110
-------
TABLE 7-2. OUTPUT FILE FOR EXAMPLE 1.
4444444444444444444444444444444
U. S. ENVIRONMENTAL PROTECTION AGENCY
EXPOSURE ASSESSMENT
MULTIMEDIA MODEL
VERSION 3.3, DECEMBER 1988
Developed by Phillip Mineart and Atul Salhotra of
Woodward-Clyde Consultants, Oakland, California
In cooperation with:
Hydrogeologic, Inc., Herndon, Virginia,
Geotrans, Inc., Herndon, Virginia,
and
Aqua Terra Consultants, Mountain View, California
Run options
Subtitle D landfill application.
Chemical simulated is DEFAULT CHEMICAL
Option Chosen
Run was
Infiltration input by user
Run was steady-state
Rej ect runs if Y coordinate outside plume
Rej ect runs if Z coordinate outside plume
Gaussian source used in saturated zone model
Saturated zone model
DETERMIN
(continued)
111
-------
TABLE 7-2. OUTPUT FILE FOR EXAMPLE 1.
CHEMICAL SPECIFIC VARIABLES
VARIABLE NAME
Solid phase decay coefficient
Dissolved phase decay coefficient
Overall chemical decay coefficient
Acid catalyzed hydrolysis rate
Neutral hydrolysis rate constant
Base catalyzed hydrolysis rate
Reference temperature
Normalized distribution coefficient
Distribution coefficient
Biodegradation coefficient (sat. zone)
Air diffusion coefficient
UNITS
1/yr
1/yr
1/yr
1/M-yr
1/yr
1/M-yr
C
ml/g
1/yr
cm2/s
Reference temperature for air diffusion C
Molecular weight
Mole fraction of solute
Vapor pressure of solute
Henry "s law constant
RFD value for drinking water
ADIF value for fish consumption
CCC for aquatic organisms
VARIABLE NAME
Infiltration rate
Area of waste disposal unit
Duration of pulse
Spread of contaminant source
Recharge rate
Source decay constant
Initial concentration at landfill
Length scale of facility
Width scale of facility
Near field dilution
g/M
--
mm Hg
atm-mA3/M
mg-kg/day
mg-kg/day
mg-kg/day
SOURCE
UNITS
m/yr
m~2
yr
m
m/yr
1/yr
mg/1
m
m
DISTRIBUTION
DERIVED
DERIVED
DERIVED
CONSTANT
CONSTANT
CONSTANT
CONSTANT
CONSTANT
DERIVED
CONSTANT
CONSTANT
CONSTANT
CONSTANT
CONSTANT
CONSTANT
CONSTANT
CONSTANT
CONSTANT
CONSTANT
SPECIFIC VARIABLES
DISTRIBUTION
CONSTANT
CONSTANT
CONSTANT
DERIVED
CONSTANT
CONSTANT
CONSTANT
DERIVED
DERIVED
CONSTANT
PARAMETERS
MEAN
O.OOOE+
O.OOOE+
O.OOOE+
O.OOOE+
O.OOOE+
O.OOOE+
25.0
O.OOOE+
0.219
O.OOOE+
O.OOOE+
O.OOOE+
-999.
-999.
-999.
-999.
1.00
1.00
1.00
STD DEV
00
00
00
00
00
00
00
00
00
00
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
.OOOE+
.OOOE+
.OOOE+
.OOOE+
.OOOE+
.OOOE+
.OOOE+
.OOOE+
.OOOE+
.OOOE+
.645E-
.OOOE+
.OOOE+
.100E-
.230E-
.OOOE+
.OOOE+
.OOOE+
.OOOE+
00
00
00
00
00
00
00
00
00
00
02
00
00
01
01
00
00
00
00
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
PARAMETERS
MEAN STD DEV
0.700E-
400.
-999.
-999.
0.760E-
O.OOOE+
1.00
-999.
-999.
O.OOOE+
02
02
00
00
-
-
-
-
-
-
-
-
-
0
999.
999.
999.
999.
999.
999.
999.
999.
999.
.OOOE+
00
0
0
0
0
0
0
0
0
0
0
LIMITS
MIN
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.100E-08
.OOOE+00
.100E-09
.OOOE+00
.OOOE+00
.OOOE+00
0
0
0
-
-
-
-
0
-
-
LIMITS
MIN
.100E-09
. 100E-01
.100E-08
.100E-08
.100E-09
.OOOE+00
.OOOE+00
.100E-08
.100E-08
.OOOE+00
0
-
-
0
0
-
-
0
0
0
MAX
.100E+11
.100E+11
.100E+11
999.
999.
999.
100.
999.
.100E+11
999.
10.0
100.
999.
1.00
100.
1.00
1.00
1.00
1.00
MAX
.100E+11
999.
999.
.100E+11
.100E+11
999.
999.
.100E+11
.100E+11
.OOOE+00
(continued)
112
-------
TABLE 7-2. OUTPUT FILE FOR EXAMPLE 1 (concluded).
AQUIFER SPECIFIC VARIABLES
VARIABLE NAME
Particle diameter
Aquifer porosity
Bulk density
Aquifer thickness
Source thickness (mixing zone depth)
Conductivity (hydraulic)
Gradient (hydraulic)
Groundwater seepage velocity
Retardation coefficient
Longitudinal dispersivity
Transverse dispersivity
Vertical dispersivity
Temperature of aquifer
pH
Organic carbon content (fraction)
Well distance from site
Angle off center
Well vertical distance
UNITS
cm
--
g/cc
m
m
m/yr
m/yr
--
m
m
m
C
--
m
degree
m
DISTRIBUTION
CONSTANT
DERIVED
DERIVED
CONSTANT
DERIVED
DERIVED
CONSTANT
DERIVED
DERIVED
CONSTANT
CONSTANT
CONSTANT
CONSTANT
CONSTANT
CONSTANT
CONSTANT
CONSTANT
CONSTANT
PARAMETERS
MEAN STD DEV
0
-
-
-
-
0
-
-
0
0
0
.630E-03
999.
999.
78.6
999.
999.
.306E-01
999.
999.
160.
15.2
8.00
14.4
6.20
.315E-02
152.
.OOOE+00
.OOOE+00
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
0.
0.
0.
0.
0.
0.
0.
0.
1
0.
0.
0.
0.
0.
0.
1
0.
0.
LIMITS
MIN
100E-
100E-
100E-
100E-
100E-
100E-
100E-
100E-
.00
100E-
100E-
100E-
OOOE+
300
100E-
.00
OOOE+
OOOE+
08
08
01
08
08
06
07
09
02
02
02
00
05
00
00
0
0
0
0
-
0
0
0
0
0
-
MAX
100.
.990
5.00
.100E+
.100E+
.100E+
999.
.100E+
.100E+
.100E+
.100E+
.100E+
100.
14.0
1.00
999.
360.
1.00
06
06
09
09
09
05
05
05
CONCENTRATION AFTER SATURATED ZONE MODEL 0.5736E-03
113
-------
TABLE 7-3. SAT.OUT FILE FOR EXAMPLE 1.
44
1
STEADY STATE SATURATED ZONE TRANSPORT RESULTS
AT 0.1000E+04 YEARS, CONCENTRATION IS 0.5736E-03
114
-------
TABLE 7-4. INPUT SEQUENCE FOR EXAMPLE 2.
444444444444444444444444444444444444444
Test input sequence for MULTIMED.
Example 2.
GENERAL DATA
*** CHEMICAL NAME FORMAT(80A1)
DEFAULT CHEMICAL
*** ISOURC
***OPTION OPTAIR RUN
200 DETERMINISTIC
ROUTE NT
MONTE I STEAD
1111
IYCHK PALPH APPTYP
IOPEN IZCHK LANDF COMPLETE
000 90.0 021
*** XST
END GENERAL
CHEMICAL SPECIFIC VARIABLE DATA
ARRAY VALUES
*** CHEMICAL SPECIFIC VARIABLES
* * *
* * *
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
END
VARIABLE NAME UNITS
Solid phase decay coeff (1/yr)
Diss phase decay coeff (1/yr)
Overall chem dcy coeff (1/yr)
Acid cataly hydrol rte(l/M-yr)
Neutral hydrol rate cons (1/yr)
Base cataly hydrol rte(l/M-yr)
Reference temperature (C)
Normalized distrib coeff (ml/g)
Distribution coefficient
Biodegrad coef (sat zone) (1/yr)
Air diffusion coeff (cm2/s)
Ref temp for air diffusion (C)
Molecular weight (g/mole)
Mole fraction of solute
Solute vapor pressure (mm Hg)
Henry^s law cons (atm-mA3/M)
Not in use
Not in use
Not in use
ARRAY
DISTRIBUTION
-1
-1
-1
0
0
0
0
0
-2
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
-
-
-
-
PARAMETERS
MEAN STD
.OOOE+
.OOOE+
.OOOE+
.OOOE+
.OOOE+
.OOOE+
25.0
.OOOE+
.219
.OOOE+
.OOOE+
.OOOE+
999.
999.
999.
999.
1.00
1.00
1.00
00
00
00
00
00
00
00
00
00
00
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
.OOOE
.OOOE
.OOOE
.OOOE
.OOOE
.OOOE
.OOOE
.OOOE
.OOOE
.OOOE
.645E
.OOOE
.OOOE
.100E
.230E
.OOOE
.OOOE
.OOOE
.OOOE
DEV
+ 00
+ 00
+ 00
+ 00
+ 00
+ 00
+ 00
+ 00
+ 00
+ 00
-02
+ 00
+ 00
-01
-01
+ 00
+ 00
+ 00
+ 00
LIMITS
MIN MAX
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.100E-08
.OOOE+00
.100E-09
.OOOE+00
.OOOE+00
.OOOE+00
0.100E+11
0.100E+11
0.100E+11
-999.
-999.
-999.
100.
-999.
0.100E+11
-999.
10.0
100.
-999.
1.00
100.
1.00
1.00
1.00
1.00
END CHEMICAL SPECIFIC VARIABLE DATA
(continued)
115
-------
TABLE 7-4. INPUT SEQUENCE FOR EXAMPLE 2.
4444444444444444444444444444444444'
SOURCE SPECIFIC VARIABLE DATA
ARRAY VALUES
*** SOURCE SPECIFIC VARIABLES
*
*
* *
* *
1
2
3
4
5
6
7
8
9
END
VARIABLE NAME UNITS
Infiltration rate (m/yr)
Area of waste disp unit (mA2)
Duration of pulse (yr)
Spread of contaminant srce (m)
Recharge rate (m/yr)
Source decay constant (1/yr)
Init cone at landfill (mg/1)
Length scale of facility (m)
Width scale of facility (m)
ARRAY
DISTRIBUTION
0
0
0
-1
0
0
0
-1
-1
PARAMETERS
MEAN STD
0.700E-02
400.
-999.
-999.
0.760E-02
O.OOOE+00
1.00
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
DEV
0
0
0
0
0
0
0
0
0
MIN
.100E
.100E
.100E
.100E
.100E
.OOOE
.OOOE
.100E
.100E
LIMITS
MAX
-09
-01
-08
-08
-09
+ 00
+ 00
-08
-08
0
-
-
0
0
-
-
0
0
.100E+11
999.
999.
.100E+11
.100E+11
999.
999.
.100E+11
.100E+11
END SOURCE SPECIFIC VARIABLE DATA
VFL UNSATURATED FLOW MODEL PARAMETERS
CONTROL PARAMETERS
*** DUMMY NMAT KPROP DUMMY NVFLAY
71211
END CONTROL PARAMETERS
MATERIAL NUMBER FOR EACH LAYER
6.10 1
END MATERIAL PARAMETERS
SATURATED MATERIAL PROPERTY PARAMETERS
ARRAY VALUES
*** SATURATED MATERIAL VARIABLES
VARIABLE NAME
UNITS
DISTRIBUTION
PARAMETERS
MEAN STD DEV
LIMITS
MIN MAX
1 Sat hydraulic conduct (cm/hr)
2 Unsaturated zone porosity
3 Air entry pressure head (m)
4 Depth of the unsat zone (m)
END ARRAY
0.170E-01 -999.
0.430 -999.
O.OOOE+00 -999.
6.10 -999.
0.100E-10 0.100E+05
0.100E-08 0.990
O.OOOE+00 -999.
0.100E-08 -999.
END MATERIAL 1
END
(continued)
116
-------
TABLE 7-4. INPUT SEQUENCE FOR EXAMPLE 2.
SOIL MOISTURE PARAMETERS
*** FUNCTIONAL COEFFICIENTS
ARRAY VALUES
*** FUNCTIONAL COEFFICIE VARIABLES
VARIABLE NAME
UNITS
DISTRIBUTION
PARAMETERS
MEAN STD DEV
LIMITS
MIN MAX
1 Residual water content
2 Brooks and Corey exponent, EN
3 ALFA van Genuchten coefficient
4 BETA Van Genuchten coefficient
END ARRAY
0.880E-01 -999.
0.500 -999.
0.900E-02 -999.
1.23 -999.
0.100E-08 1.00
O.OOOE+00 10.0
O.OOOE+00 1.00
1.00 5.00
END MATERIAL 1
END
END UNSATURATED FLOW
VTP UNSATURATED TRANSPORT MODEL
CONTROL PARAMETERS
*** NLAY DUMMY IADU
1 20 1
*** WTFUN
1.200
ISOL
1
N
18
NTEL
3
NGPTS
104
NIT
2
DUMMY
1
DUMMY
1
END CONTROL PARAMETERS
TRANSPORT PARAMETER
ARRAY VALUES
*** UNSATURATED TRANSPOR VARIABLES
VARIABLE NAME
UNITS
DISTRIBUTION
PARAMETERS
MEAN STD DEV
LIMITS
MIN MAX
1 Thickness of layer (m)
2 Longit disper of layer (m)
3 Percent organic matter
4 Bulk dens of soil layer (g/cc)
5 Biological decay coeff (1/yr)
END ARRAY
0 6.10 -999. 0.100E-08 -999.
0 0.400 -999. O.OOOE+00 0.100E+05
0 0.260E-01 -999. O.OOOE+00 100.
0 1.67 -999. 0.100E-01 5.00
0 O.OOOE+00 -999. O.OOOE+00 -999.
END LAYER 1
END UNSATURATED TRANSPORT PARAMETERS
END TRANSPORT MODEL
(continued)
117
-------
TABLE 7-4. INPUT SEQUENCE FOR EXAMPLE 2 (concluded).
AQUIFER SPECIFIC VARIABLE DATA
ARRAY VALUES
*** AQUIFER SPECIFIC VARIABLES
* * *
* * *
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
END
VARIABLE NAME UNITS
Particle diameter (cm)
Aquifer porosity
Bulk density (g/cc)
Aquifer thickness (m)
Mixing zone depth (m)
Hydraulic conductivity (m/yr)
Hydraulic Gradient
Grndwater seep velocity (m/yr)
Retardation coefficient
Longitudinal dispersivity (m)
Transverse dispersivity (m)
Vertical dispersivity (m)
Temperature of aquifer (C)
pH
Organic carbon content (fract)
Receptor distance from site(m)
Angle off center (degree)
Well vert dist from water tabl
ARRAY
DISTRIBUTION PARAMETERS
MEAN STD DEV
0
-2
-2
0
-1
-2
0
-2
-1
0
0
0
0
0
0
0
0
0
0.630E-03
-999.
-999.
78.6
-999.
-999.
0.306E-01
-999.
-999.
160.
15.2
8.00
14.4
6.20
0.315E-02
152.
O.OOOE+00
O.OOOE+00
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
0.
0.
0.
0.
0.
0.
0.
0.
1
0.
0.
0.
0.
0.
0.
1
0.
0.
LIMITS
MIN MAX
100E-
100E-
100E-
100E-
100E-
100E-
100E-
100E-
.00
100E-
100E-
100E-
OOOE+
300
100E-
.00
OOOE+
OOOE+
08
08
01
08
08
06
07
09
02
02
02
00
05
00
00
0
0
0
0
-
0
0
0
0
0
-
100.
.990
5.00
.100E+
.100E+
.100E+
999.
.100E+
.100E+
.100E+
.100E+
.100E+
100.
14.0
1.00
999.
360.
1.00
06
06
09
09
09
05
05
05
END AQUIFER SPECIFIC VARIABLE DATA
END ALL DATA
118
-------
TABLE 7-5. MAIN OUTPUT FILE FOR EXAMPLE 2.
U. S. ENVIRONMENTAL PROTECTION AGENCY
EXPOSURE ASSESSMENT
MULTIMEDIA MODEL
VERSION 3.3, DECEMBER 1988
Developed by Phillip Mineart and Atul Salhotra of
Woodward-Clyde Consultants, Oakland, California
In cooperation with:
Hydrogeologic, Inc., Herndon, Virginia,
Geotrans, Inc., Herndon, Virginia,
and
Aqua Terra Consultants, Mountain View, California
Run options
Subtitle D landfill application.
Chemical simulated is DEFAULT CHEMICAL
Option Chosen
Run was
Infiltration input by user
Run was steady-state
Rej ect runs if Y coordinate outside plume
Rej ect runs if Z coordinate outside plume
Gaussian source used in saturated zone model
Saturated and unsaturated zone models
DETERMIN
UNSATURATED ZONE FLOW MODEL PARAMETERS
(input parameter description and value)
NP - Total number of nodal points
NMAT - Number of different porous materials
KPROP - Van Genuchten or Brooks and Corey
IMSHGN - Spatial discretization option
1
240
1
2
1
OPTIONS CHOSEN
Brooks and Corey functional coefficients
User defined coordinate system
(continued)
119
-------
TABLE 7-5. MAIN OUTPUT FILE FOR EXAMPLE 2.
4444444444444444444444
Layer information
LAYER NO. LAYER THICKNESS MATERIAL PROPERTY
1 6.10 1
DATA FOR MATERIAL 1
VADOSE ZONE MATERIAL VARIABLES
VARIABLE NAME
Saturated hydraulic conductivity
Unsaturated zone porosity
Air entry pressure head
Depth of the unsaturated zone
UNITS
cm/hr
--
m
m
DISTRIBUTION
CONSTANT
CONSTANT
CONSTANT
CONSTANT
PARAMETERS
0
0
0
MEAN
.170E-01
.430
.OOOE+00
6.10
STD DEV
-999.
-999.
-999.
-999.
0
0
0
0
LIMITS
MIN
. 100E-
. 100E-
.OOOE+
. 100E-
10
08
00
08
0
0
-
-
MAX
.100E+
.990
999.
999.
05
UNSATURATED ZONE TRANSPORT MODEL PARAMETERS
NLAY - Number of different layers used 1
NTSTPS - Number of time values concentration calc 20
DUMMY - Not presently used 1
ISOL - Type of scheme used in unsaturated zone 1
N - Stehfest terms or number of increments 18
NTEL - Points in Lagrangian interpolation 3
NGPTS - Number of Gauss points 104
NIT - Convolution integral segments 2
IBOUND - Type of boundary condition 1
ITSGEN - Time values generated or input 1
TMAX - Max simulation time -- 0.0
WTFUN - Weighting factor -- 1.2
OPTIONS CHOSEN
Stehfest numerical inversion algorithm
Nondecaying continuous source
Computer generated times for computing concentrations
(continued)
120
-------
TABLE 7-5. MAIN OUTPUT FILE FOR EXAMPLE 2.
DATA FOR LAYER 1
VADOSE TRANSPORT VARIABLES
VARIABLE NAME
Thickness of layer
Longitudinal dispersivity of layer
Percent organic matter
Bulk density of soil for layer
Biological decay coefficient
VARIABLE NAME
Solid phase decay coefficient
Dissolved phase decay coefficient
Overall chemical decay coefficient
Acid catalyzed hydrolysis rate
Neutral hydrolysis rate constant
Base catalyzed hydrolysis rate
Reference temperature
Normalized distribution coefficient
Distribution coefficient
Biodegradation coefficient (sat. zone)
Air diffusion coefficient
UNITS
m
m
--
g/cc
1/yr
CHEMICAL
UNITS
i/yr
1/yr
1/yr
1/M-yr
1/yr
1/M-yr
C
ml/g
1/yr
cm2/s
Reference temperature for air diffusion C
Molecular weight
Mole fraction of solute
Vapor pressure of solute
Henry "s law constant
RFD value for drinking water
ADIF value for fish consumption
CCC for aquatic organisms
g/M
--
mm Hg
atm-mA3/M
mg-kg/day
mg-kg/day
mg-kg/day
DISTRIBUTION
CONSTANT
CONSTANT
CONSTANT
CONSTANT
CONSTANT
SPECIFIC VARIABLES
DISTRIBUTION
DERIVED
DERIVED
DERIVED
CONSTANT
CONSTANT
CONSTANT
CONSTANT
CONSTANT
DERIVED
CONSTANT
CONSTANT
CONSTANT
CONSTANT
CONSTANT
CONSTANT
CONSTANT
CONSTANT
CONSTANT
CONSTANT
PARAMETERS
0
0
0
MEAN
6.10
.400
.260E-
1.67
.OOOE+
01
00
-
-
-
-
-
STD DEV
999.
999.
999.
999.
999.
0
0
0
0
0
PARAMETERS
MEAN STD DEV
0
0
0
0
0
0
0
0
0
0
0
-
-
-
-
.OOOE+
.OOOE+
.OOOE+
.OOOE+
.OOOE+
.OOOE+
25.0
.OOOE+
.219
.OOOE+
.OOOE+
.OOOE+
999.
999.
999.
999.
1.00
1.00
1.00
00
00
00
00
00
00
00
00
00
00
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.645E-02
.OOOE+00
.OOOE+00
.100E-01
.230E-01
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
MIN
.100E
.OOOE
.OOOE
.100E
.OOOE
MIN
.OOOE
.OOOE
.OOOE
.OOOE
.OOOE
.OOOE
.OOOE
.OOOE
.OOOE
.OOOE
.OOOE
.OOOE
.OOOE
.100E
.OOOE
.100E
.OOOE
.OOOE
.OOOE
LIMITS
-08 -
+ 00 0
+ 00
-01
+ 00 -
LIMITS
+ 00 0
+ 00 0
+ 00 0
+ 00 -
+ 00 -
+ 00 -
+ 00
+ 00 -
+ 00 0
+ 00 -
+ 00
+ 00
+ 00 -
-08
+ 00
-09
+ 00
+ 00
+ 00
MAX
999.
.100E+05
100.
5.00
999.
MAX
.100E+11
.100E+11
.100E+11
999.
999.
999.
100.
999.
.100E+11
999.
10.0
100.
999.
1.00
100.
1.00
1.00
1.00
1.00
(continued)
121
-------
TABLE 7-5. MAIN OUTPUT FILE FOR EXAMPLE 2 (concluded).
SOURCE SPECIFIC VARIABLES
VARIABLE NAME
Infiltration rate
Area of waste disposal unit
Duration of pulse
Spread of contaminant source
Recharge rate
Source decay constant
Initial concentration at landfill
Length scale of facility
Width scale of facility
Near field dilution
VARIABLE NAME
Particle diameter
Aquifer porosity
Bulk density
Aquifer thickness
Source thickness (mixing zone depth)
Conductivity (hydraulic)
Gradient (hydraulic)
Groundwater seepage velocity
Retardation coefficient
Longitudinal dispersivity
Transverse dispersivity
Vertical dispersivity
Temperature of aquifer
pH
Organic carbon content (fraction)
Well distance from site
Angle off center
Well vertical distance
UNITS
m/yr
m~2
yr
m
m/yr
1/yr
mg/1
m
m
AQUIFER
UNITS
cm
--
g/cc
m
m
m/yr
m/yr
--
m
m
m
C
--
m
degree
m
DISTRIBUTION
CONSTANT
CONSTANT
CONSTANT
DERIVED
CONSTANT
CONSTANT
CONSTANT
DERIVED
DERIVED
CONSTANT
SPECIFIC VARIABLES
DISTRIBUTION
CONSTANT
DERIVED
DERIVED
CONSTANT
DERIVED
DERIVED
CONSTANT
DERIVED
DERIVED
CONSTANT
CONSTANT
CONSTANT
CONSTANT
CONSTANT
CONSTANT
CONSTANT
CONSTANT
CONSTANT
PARAMETERS
MEAN STD DEV
0
-
-
0
0
-
-
0
.700E-02
400.
999.
999.
.760E-02
.OOOE+00
1.00
999.
999.
.OOOE+00
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
0. OOOE+00
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
PARAMETERS
MEAN STD DEV
0
-
-
-
-
0
-
-
0
0
0
.630E-03
999.
999.
78.6
999.
999.
.306E-01
999.
999.
160.
15.2
8.00
14.4
6.20
.315E-02
152.
.OOOE+00
.OOOE+00
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
0.
0.
0.
0.
0.
0.
0.
0.
1
0.
0.
0.
0.
0.
0.
1
0.
0.
MIN
100E
100E
100E
100E
100E
OOOE
OOOE
100E
100E
OOOE
MIN
100E
100E
100E
100E
100E
100E
100E
100E
.00
100E
100E
100E
OOOE
300
100E
.00
OOOE
OOOE
LIMITS
-09
-01
-08
-08
-09
+ 00
+ 00
-08
-08
+ 00
0
-
-
0
0
-
-
0
0
0
LIMITS
-08
-08
-01
-08
-08
-06
-07
-09
-02
-02
-02
+ 00
-05
+ 00
+ 00
0
0
0
0
-
0
0
0
0
0
-
MAX
.100E+11
999.
999.
.100E+11
.100E+11
999.
999.
.100E+11
.100E+11
.OOOE
MAX
100.
.990
5.00
.100E
.100E
.100E
999.
.100E
.100E
.100E
.100E
.100E
100.
14.0
1.00
999.
360.
1.00
+ 00
+ 06
+ 06
+ 09
+ 09
+ 09
+ 05
+ 05
+ 05
CONCENTRATION AFTER SATURATED ZONE MODEL 0.5736E-03
122
-------
TABLE 7-6. SAT.OUT FILE FOR EXAMPLE 2.
44
1
STEADY STATE SATURATED ZONE TRANSPORT RESULTS
AT 0.1000E+04 YEARS, CONCENTRATION IS 0.5736E-03
123
-------
7.3 EXAMPLE 3
7.3.1 The Hypothetical Scenario
The third example is similar to Example 2. The difference is that Example 3 is
run in Monte-Carlo mode instead of in a deterministic framework. In this
example, spatial variability is observed in the measured values for two
parameters, which introduces uncertainty into the model. Therefore, it is
necessary to utilize the Monte Carlo option in MULTIMED.
In Example 3, all but three of the parameter values are constant or derived and
are identical to those in Example 2. The three parameters have some uncertainty
associated with their values. Thus, they are described in terms of probability
density functions which represent the uncertainty in the parameter value. The
theory behind the Monte Carlo analysis technique, and the probability density
distributions included in MULTIMED, are discussed in Section 9 of Salhotra et al.
(1990) .
The three uncertain parameters in Example 3 are the unsaturated zone hydraulic
conductivity (cm/hr), the unsaturated zone porosity, and the aquifer pH. In this
example, the probability density distribution is lognormal for the hydraulic
conductivity, normal for the unsaturated zone porosity, and uniform for the
aquifer pH. The normal and lognormal distributions both require specification of
a mean, standard deviation, and minimum and maximum limits. The uniform
distribution requires only the minimum and maximum limits of values. Values for
these parameters are shown in Table 7-7.
7.3.2 Input
The input sequence for Example 3 is shown in Table 7-8. It is identical to the
input file for Example 2 except for changes in the General Data Group related to
running the model in a Monte Carlo framework, and differences in the input for
the three parameters which have been assigned Monte Carlo distributions.
TABLE 7-7. MONTE CARLO DISTRIBUTION VALUES IN EXAMPLE 3
4444444444444444444444444444444444444444444444444444444444444444444
Standard Limits
Parameter Distribution Mean Deviation Min. Max.
Saturated hydraulic
conductivity (cm/hr)
for the unsaturated zone Lognormal .017 .020 .001 .250
Unsaturated zone
porosity Normal .330 .100 .200 .450
Aquifer pH Uniform NA NA 5.80 6.90
124
-------
TABLE 7-8. INPUT SEQUENCE FOR EXAMPLE 3.
Example 3 input
Subtitle D application
GENERAL DATA
*** CHEMICAL NAME FORMAT(80A1)
DEFAULT CHEMICAL
*** ISOURC
***OPTION OPTAIR RUN
200 MONTE
ROUTE NT
MONTE I STEAD
500 111
IYCHK PALPH APPTYP
IOPEN IZCHK LANDF COMPLETE
100 90.0 021
*** XST
END GENERAL
CHEMICAL SPECIFIC VARIABLE DATA
ARRAY VALUES
*** CHEMICAL SPECIFIC VARIABLES
* * *
* * *
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
END
VARIABLE NAME UNITS
Solid phase decay coeff (1/yr)
Diss phase decay coeff (1/yr)
Overall chem dcy coeff (1/yr)
Acid cataly hydrol rte(l/M-yr)
Neutral hydrol rate cons (1/yr)
Base cataly hydrol rte(l/M-yr)
Reference temperature (C)
Normalized distrib coeff (ml/g)
Distribution coefficient
Biodegrad coef (sat zone) (1/yr)
Air diffusion coeff (cm2/s)
Ref temp for air diffusion (C)
Molecular weight (g/mole)
Mole fraction of solute
Solute vapor pressure (mm Hg)
Henry^s law cons (atm-mA3/M)
Not in use
Not in use
Not in use
ARRAY
DISTRIBUTION
-1
-1
-1
0
0
0
0
0
-2
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
-
-
-
-
PARAMETERS
MEAN STD
.OOOE+
.OOOE+
.OOOE+
.OOOE+
.OOOE+
.OOOE+
25.0
140.
.219
.OOOE+
.OOOE+
.OOOE+
999.
999.
999.
999.
1.00
1.00
1.00
00
00
00
00
00
00
00
00
00
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
.OOOE
.OOOE
.OOOE
.OOOE
.OOOE
.OOOE
.OOOE
.OOOE
.OOOE
.OOOE
.645E
.OOOE
.OOOE
.100E
.230E
.OOOE
.OOOE
.OOOE
.OOOE
DEV
+ 00
+ 00
+ 00
+ 00
+ 00
+ 00
+ 00
+ 00
+ 00
+ 00
-02
+ 00
+ 00
-01
-01
+ 00
+ 00
+ 00
+ 00
LIMITS
MIN MAX
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.100E-08
.OOOE+00
.100E-09
.OOOE+00
.OOOE+00
.OOOE+00
0.100E+11
0.100E+11
0.100E+11
-999.
-999.
-999.
100.
-999.
0.100E+11
-999.
10.0
100.
-999.
1.00
100.
1.00
1.00
1.00
1.00
END CHEMICAL SPECIFIC VARIABLE DATA
(continued)
125
-------
TABLE 7-8. INPUT SEQUENCE FOR EXAMPLE 3.
SOURCE SPECIFIC VARIABLE DATA
ARRAY VALUES
*** SOURCE SPECIFIC VARIABLES
*
*
* *
* *
1
2
3
4
5
6
7
8
9
END
VARIABLE NAME UNITS
Infiltration rate (m/yr)
Area of waste disp unit (mA2)
Duration of pulse (yr)
Spread of contaminant srce (m)
Recharge rate (m/yr)
Source decay constant (1/yr)
Init cone at landfill (mg/1)
Length scale of facility (m)
Width scale of facility (m)
ARRAY
DISTRIBUTION
0
0
0
-1
0
0
0
-1
-1
PARAMETERS
MEAN STD
0.700E-02
400.
-999.
-999.
0.160E-01
O.OOOE+00
1.00
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
DEV
0
0
0
0
0
0
0
0
0
MIN
.100E
.100E
.100E
.100E
.100E
.OOOE
.OOOE
.100E
.100E
LIMITS
MAX
-09
-01
-08
-08
-09
+ 00
+ 00
-08
-08
0
-
-
0
0
-
-
0
0
.100E+11
999.
999.
.100E+11
.100E+11
999.
999.
.100E+11
.100E+11
END SOURCE SPECIFIC VARIABLE DATA
VFL UNSATURATED FLOW MODEL PARAMETERS
CONTROL PARAMETERS
*** DUMMY NMAT KPROP DUMMY NVFLAY
71111
END CONTROL PARAMETERS
SATURATED MATERIAL PROPERTY PARAMETERS
ARRAY VALUES
*** SATURATED MATERIAL VARIABLES
VARIABLE NAME
UNITS
DISTRIBUTION
PARAMETERS
MEAN STD DEV
LIMITS
MIN MAX
1 Sat hydraulic conduct (cm/hr)
2 Unsaturated zone porosity
3 Air entry pressure head (m)
4 Depth of the unsat zone (m)
END ARRAY
2 0.170E-01 0.200E-01 0.100E-03 0.250
1 0.330 0.100 0.200 0.450
0 O.OOOE+00 -999. O.OOOE+00 -999.
0 6.10 -999. 0.100E-08 -999.
END MATERIAL 1
END
(continued)
126
-------
TABLE 7-8. INPUT SEQUENCE FOR EXAMPLE 3.
SOIL MOISTURE PARAMETERS
*** FUNCTIONAL COEFFICIENTS
ARRAY VALUES
*** FUNCTIONAL COEFFICIE VARIABLES
VARIABLE NAME
UNITS
DISTRIBUTION
PARAMETERS
MEAN STD DEV
LIMITS
MIN MAX
1 Residual water content
2 Brooks and Corey exponent, EN
3 ALFA van Genuchten coefficient
4 BETA Van Genuchten coefficient
END ARRAY
0.880E-01 -999.
0.500 -999.
0.900E-02 -999.
1.23 -999.
0.100E-08 1.00
O.OOOE+00 10.0
O.OOOE+00 1.00
1.00 5.00
END MATERIAL 1
END
END UNSATURATED FLOW
VTP UNSATURATED TRANSPORT MODEL
CONTROL PARAMETERS
*** NLAY DUMMY IADU
1 20 1
*** WTFUN
1.200
ISOL
1
N
18
NTEL
3
NGPTS
104
NIT
2
DUMMY
1
DUMMY
1
END CONTROL PARAMETERS
TRANSPORT PARAMETER
ARRAY VALUES
*** UNSATURATED TRANSPOR VARIABLES
VARIABLE NAME
UNITS
DISTRIBUTION
PARAMETERS
MEAN STD DEV
LIMITS
MIN MAX
1 Thickness of layer (m)
2 Longit disper of layer (m)
3 Percent organic matter
4 Bulk dens of soil layer (g/cc)
5 Biological decay coeff (1/yr)
END ARRAY
0 6.10 -999. 0.100E-08 -999.
0 0.400 -999. O.OOOE+00 0.100E+05
0 0.260E-01 -999. O.OOOE+00 100.
0 1.45 -999. 0.100E-01 5.00
0 O.OOOE+00 -999. O.OOOE+00 -999.
END LAYER 1
END UNSATURATED TRANSPORT PARAMETERS
END TRANSPORT MODEL
(continued)
127
-------
TABLE 7-8. INPUT SEQUENCE FOR EXAMPLE 3 (concluded).
AQUIFER SPECIFIC VARIABLE DATA
ARRAY VALUES
*** AQUIFER SPECIFIC VARIABLES
* * *
* * *
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
END
VARIABLE NAME UNITS
Particle diameter (cm)
Aquifer porosity
Bulk density (g/cc)
Aquifer thickness (m)
Mixing zone depth (m)
Hydraulic conductivity (m/yr)
Hydraulic Gradient
Grndwater seep velocity (m/yr)
Retardation coefficient
Longitudinal dispersivity (m)
Transverse dispersivity (m)
Vertical dispersivity (m)
Temperature of aquifer (C)
pH
Organic carbon content (fract)
Receptor distance from site(m)
Angle off center (degree)
Well vert dist from water tabl
ARRAY
DISTRIBUTION PARAMETERS
MEAN STD DEV
0
-2
-2
0
-1
-2
0
-2
-1
1
0
0
0
4
0
0
0
0
0.630E-03
-999.
-999.
78.6
-999.
-999.
0.306E-01
-999.
-999.
160.
15.2
8.00
14.4
-999.
0.315E-02
152.
O.OOOE+00
O.OOOE+00
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
15.0
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
0
0
0
0
0
0
0
0
0
0
0
0
0
0
LIMITS
MIN MAX
.100E-
.100E-
.100E-
.100E-
.100E-
.100E-
.100E-
.100E-
1.00
50.0
.100E-
.100E-
.OOOE+
5.80
.100E-
1.00
.OOOE+
.OOOE+
08
08
01
08
08
06
07
09
02
02
00
05
00
00
0
0
0
0
-
0
0
0
0
-
100.
.990
5.00
.100E+
.100E+
.100E+
999.
.100E+
.100E+
200.
.100E+
.100E+
100.
6.90
1.00
999.
360.
1.00
06
06
09
09
09
05
05
END AQUIFER SPECIFIC VARIABLE DATA
END ALL DATA
128
-------
The type of distribution associated with each parameter is indicated in the
"Distribution" column. The number assigned to each of the distribution types is
shown in Table A-4. A value of 0 in the "Distribution" column indicates a
constant value for the parameter. A value of -1 or -2 indicates that the
parameter is derived from other parameters in the code. As Table A-4 indicates,
other values are used for Monte Carlo distributions. For example, the saturated
hydraulic conductivity for Material 1 in the unsaturated zone has a value of 2 in
the "Distribution" column, which indicates that a lognormal probability density
distribution has been assigned to the parameter.
7.3.3 Output
The output from MULTIMED is presented in Tables 7-9 through 7-11. Because the
General Data Group flag for the level of output from Monte Carlo runs was set to
SOME for this example problem (see Section 5.3.2.2), the output consists of the
main output file, the STATS.OUT file, and the SAT1.OUT file. The main output
file consists of an echo of the input parameters, selected statistical results,
and printer plots of frequency and cumulative frequency. The STATS.OUT file
contains a summary of the statistical analyses resulting from the Monte Carlo
simulations. The cumulative distribution function of well concentrations (i.e.,
well concentrations in ascending order) is listed in the SAT1.0UT file. This
file can be used by the postprocessor, POSTMED, to produce frequency and
cumulative frequency plots of higher quality than those found in the main output
file. Examples of these plots are shown in Section 4.2.
129
-------
TABLE 7-9. MAIN OUTPUT FILE FOR EXAMPLE 3.
U. S. ENVIRONMENTAL PROTECTION AGENCY
EXPOSURE ASSESSMENT
MULTIMEDIA MODEL
VERSION 3.3, DECEMBER 1988
Developed by Phillip Mineart and Atul Salhotra of
Woodward-Clyde Consultants, Oakland, California
In cooperation with:
Hydrogeologic, Inc., Herndon, Virginia,
Geotrans, Inc., Herndon, Virginia,
and
Aqua Terra Consultants, Mountain View, California
Run options
Example 3 input
Subtitle D application
Chemical simulated is DEFAULT CHEMICAL
Option Chosen
Run was
Infiltration input by user
Number of monte carlo simulations 500
Run was steady-state
Rej ect runs if Y coordinate outside plume
Rej ect runs if Z coordinate outside plume
Gaussian source used in saturated zone model
Saturated and unsaturated zone models
MONTE
UNSATURATED ZONE FLOW MODEL PARAMETERS
(input parameter description and value)
NP - Total number of nodal points
NMAT - Number of different porous materials
KPROP - Van Genuchten or Brooks and Corey
IMSHGN - Spatial discretization option
1
240
1
1
1
(continued)
130
-------
TABLE 7-9. MAIN OUTPUT FILE FOR EXAMPLE 3.
OPTIONS CHOSEN
Van Genuchten functional coefficients
User defined coordinate system
Layer information
LAYER NO. LAYER THICKNESS
1 0.00
MATERIAL PROPERTY
1
DATA FOR MATERIAL 1
VADOSE ZONE MATERIAL VARIABLES
VARIABLE NAME
Saturated hydraulic conductivity
Unsaturated zone porosity
Air entry pressure head
Depth of the unsaturated zone
UNITS
cm/hr
--
m
m
DISTRIBUTION
LOG NORMAL
NORMAL
CONSTANT
CONSTANT
PARAMETERS
0
0
0
MEAN
.170E-01
.330
.OOOE+00
6.10
0
0
-
-
STD DEV
.200E-01
.100
999.
999.
0
0
0
0
LIMITS
MIN
.100E-
.200
.OOOE+
. 100E-
03
00
08
0
0
-
-
MAX
.250
.450
999.
999.
DATA FOR MATERIAL 1
VADOSE ZONE FUNCTION VARIABLES
VARIABLE NAME
UNITS
DISTRIBUTION
PARAMETERS
MEAN STD DEV
LIMITS
MIN MAX
Residual water content
Brook and Corey exponent,EN
ALFA coefficient
Van Genuchten exponent, ENN
I/cm
CONSTANT
CONSTANT
CONSTANT
CONSTANT
0.880E-01 -999.
0.500 -999.
0.900E-02 -999.
1.23 -999.
0.100E-08 1.00
0.OOOE+00 10.0
0.OOOE+00 1.00
1.00 5.00
(continued)
131
-------
TABLE 7-9. MAIN OUTPUT FILE FOR EXAMPLE 3.
UNSATURATED ZONE TRANSPORT MODEL PARAMETERS
NLAY - Number of different layers used 1
NTSTPS - Number of time values concentration calc 20
DUMMY - Not presently used 1
ISOL - Type of scheme used in unsaturated zone 1
N - Stehfest terms or number of increments 18
NTEL - Points in Lagrangian interpolation 3
NGPTS - Number of Gauss points 104
NIT - Convolution integral segments 2
IBOUND - Type of boundary condition 1
ITSGEN - Time values generated or input 1
TMAX - Max simulation time -- 0.0
WTFUN - Weighting factor -- 1.2
OPTIONS CHOSEN
Stehfest numerical inversion algorithm
Nondecaying continuous source
Computer generated times for computing concentrations
DATA FOR LAYER 1
VADOSE TRANSPORT VARIABLES
VARIABLE NAME
UNITS
DISTRIBUTION
PARAMETERS
MEAN STD DEV
LIMITS
MIN MAX
Thickness of layer
Longitudinal dispersivity of layer
Percent organic matter
Bulk density of soil for layer
Biological decay coefficient
m
m
--
g/cc
1/yr
CONSTANT
CONSTANT
CONSTANT
CONSTANT
CONSTANT
0
0
0
6
1
.10
400
260E-
.45
OOOE+
01
00
-999.
-999.
-999.
-999.
-999.
0
0
0
0
0
.100E-08
.OOOE+00
.OOOE+00
. 100E-01
.OOOE+00
-999.
0.100E+
100.
5.00
-999.
05
(continued)
132
-------
TABLE 7-9. MAIN OUTPUT FILE FOR EXAMPLE 3.
CHEMICAL SPECIFIC VARIABLES
VARIABLE NAME
LIMITS
Solid phase decay coefficient
Dissolved phase decay coefficient
Overall chemical decay coefficient
Acid catalyzed hydrolysis rate
Neutral hydrolysis rate constant
Base catalyzed hydrolysis rate
Reference temperature
Normalized distribution coefficient
Distribution coefficient
Biodegradation coefficient (sat. zone)
Air diffusion coefficient
Reference temperature for air diffusion
Molecular weight
Mole fraction of solute
Vapor pressure of solute
Henry "s law constant
RFD value for drinking water
ADIF value for fish consumption
CCC for aquatic organisms
UNITS
1/yr
1/yr
1/yr
1/M-yr
1/yr
1/M-yr
C
ml/g
1/yr
cm2/s
C
g/M
--
mm Hg
atm-mA3/M
mg-kg/day
mg-kg/day
mg-kg/day
DISTRIBUTION
MEAN
DERIVED
DERIVED
DERIVED
CONSTANT
CONSTANT
CONSTANT
CONSTANT
CONSTANT
DERIVED
CONSTANT
CONSTANT
CONSTANT
CONSTANT
CONSTANT
CONSTANT
CONSTANT
CONSTANT
CONSTANT
CONSTANT
STD DEV
O.OOOE+00
O.OOOE+00
O.OOOE+00
O.OOOE+00
O.OOOE+00
O.OOOE+00
25.0
140.
0.219
O.OOOE+00
O.OOOE+00
O.OOOE+00
-999.
-999.
-999.
-999.
1.00
1.00
1.00
PARAMETERS
MIN MAX
O.OOOE+00 O.OOOE+00
O.OOOE+00 O.OOOE+00
O.OOOE+00 O.OOOE+00
O.OOOE+00 O.OOOE+00
O.OOOE+00 O.OOOE+00
O.OOOE+00 O.OOOE+00
O.OOOE+00 O.OOOE+00
O.OOOE+00 O.OOOE+00
O.OOOE+00 O.OOOE+00
O.OOOE+00 O.OOOE+00
0.645E-02 O.OOOE+00
O.OOOE+00 O.OOOE+00
O.OOOE+00 O.OOOE+00
0.100E-01 0.100E-08
0.230E-01 O.OOOE+00
O.OOOE+00 0.100E-09
O.OOOE+00 O.OOOE+00
O.OOOE+00 O.OOOE+00
O.OOOE+00 O.OOOE+00
0.100E+11
0.100E+11
0.100E+11
-999.
-999.
-999.
100.
-999.
0.100E+11
-999.
10.0
100.
-999.
1.00
100.
1.00
1.00
1.00
1.00
SOURCE SPECIFIC VARIABLES
VARIABLE NAME
Infiltration rate
Area of waste disposal unit
Duration of pulse
Spread of contaminant source
Recharge rate
Source decay constant
Initial concentration at landfill
Length scale of facility
Width scale of facility
Near field dilution
UNITS DISTRIBUTION
m/yr
m~2
yr
m
m/yr
1/yr
mg/1
m
m
CONSTANT
CONSTANT
CONSTANT
DERIVED
CONSTANT
CONSTANT
CONSTANT
DERIVED
DERIVED
CONSTANT
PARAMETERS
MEAN STD DEV
0.700E-02 -999.
400. -999.
-999. -999.
-999. -999.
0.160E-01 -999.
O.OOOE+00 -999.
1.00 -999.
-999. -999.
-999. -999.
O.OOOE+00 O.OOOE+00
LIMITS
MIN MAX
0.100E-09 0.100E+11
0.100E-01 -999.
0.100E-08 -999.
0.100E-08 0.100E+11
0.100E-09 0.100E+11
O.OOOE+00 -999.
O.OOOE+00 -999.
0.100E-08 0.100E+11
0.100E-08 0.100E+11
O.OOOE+00 O.OOOE+00
(continued)
133
-------
TABLE 7-9. MAIN OUTPUT FILE FOR EXAMPLE 3.
AQUIFER SPECIFIC VARIABLES
VARIABLE NAME
Particle diameter
Aquifer porosity
Bulk density
Aquifer thickness
Source thickness (mixing zone
Conductivity (hydraulic)
Gradient (hydraulic)
Groundwater seepage velocity
Retardation coefficient
Longitudinal dispersivity
Transverse dispersivity
Vertical dispersivity
Temperature of aquifer
pH
UNITS
cm
--
g/cc
m
depth) m
m/yr
m/yr
--
m
m
m
C
--
Organic carbon content (fraction)
Well distance from site
Angle off center
Well vertical distance
0 Values generated which exceeded
m
degree
m
the specified bounds.
PI
DISTRIBUTION
CONSTANT
DERIVED
DERIVED
CONSTANT
DERIVED
DERIVED
CONSTANT
DERIVED
DERIVED
NORMAL
CONSTANT
CONSTANT
CONSTANT
UNIFORM
CONSTANT
CONSTANT
CONSTANT
CONSTANT
rQTTT.TQ
PARAMETERS
MEAN STD DEV
0.630E-03
-999.
-999.
78.6
-999.
-999.
0.306E-01
-999.
-999.
160.
15.2
8.00
14.4
-999.
0.315E-02
152.
O.OOOE+00
O.OOOE+00
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
15.0
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
LIMITS
MIN MAX
0.100E-08
0.100E-08
0.100E-01
0.100E-08
0.100E-08
0.100E-06
0.100E-07
0.100E-09
1.00
50.0
0.100E-02
0.100E-02
O.OOOE+00
5.80
0.100E-05
1.00
O.OOOE+00
O.OOOE+00
100.
0.990
5.00
0.100E+06
0.100E+06
0.100E+09
-999.
0.100E+09
0.100E+09
200.
0.100E+05
0.100E+05
100.
6.90
1.00
-999.
360.
1.00
SATURATED ZONE TRANSPORT
Example 3 input
Subtitle D application
N = 500
MEAN = 0.573E-03
STANDARD DEVIATION = 0.346E-04
COEFFICIENT OF VARIATION = 0.604E-01
MINIMUM VALUE = 0.475E-03
MAXIMUM VALUE = 0.657E-03
50th PERCENTILE = 0.573E-03
80th PERCENTILE = 0.602E-03
85th PERCENTILE = 0.608E-03
90th PERCENTILE = 0.619E-03
95th PERCENTILE = 0.634E-03
90. PERCENT CONFIDENCE INTERVAL
0.570E-03
0.599E-03
0.605E-03
0.614E-03
0.626E-03
0.576E-03
0.605E-03
0.614E-03
0.623E-03
0.640E-03
(continued)
134
-------
TABLE 7-9. MAIN OUTPUT FILE FOR EXAMPLE 3.
-999 UNABLE TO COMPUTE CONFIDENCE BOUND DUE TO INSUFFICIENT DATA
VALUE % OF TIME EQUALLED % OF TIME IN INTERVAL
OR EXCEEDED
0.100E-03 100.000
0.000
0.156E-03 100.000
0.000
0.211E-03 100.000
0.000
0.267E-03 100.000
0.000
0.323E-03 100.000
0.000
0.378E-03 100.000
0.000
0.434E-03 100.000
0.800
0.490E-03 99.200
21.400
0.546E-03 77.800
56.800
0.601E-03 21.000
20.800
0.657E-03 0.200
(continued)
135
-------
TABLE 7-9. MAIN OUTPUT FILE FOR EXAMPLE 3.
100
80
F
R
E
Q 60
U
E
N
C 40
Y
20
0 + *__ + *__ + *__ + *__ + *__ + *__ + *__ + *__ + *__ + *__ +
0.100 0.156 0.211 0.267 0.323 0.378 0.434 0.490 0.546 0.601 0.657
* 0.1E-02
CONCENTRATION
(continued)
136
-------
TABLE 7-9. MAIN OUTPUT FILE FOR EXAMPLE 3.
1
C 100 +--
U !
M !
U !
L 80 +--
A !
T !
I !
V 60 +--
E !
F !
R 40 +--
E !
Q !
U !
E 20 +--
N !
C !
Y !
0 +**
0.100
H H H H H H H H H **
*** i
* i
* i
i
* i
* i
* i
i
* i
i
* i
i
* i
* i
** i
0.156 0.211 0.267 0.323 0.378 0.434 0.490 0.546 0.601 0.657
* 0.1E-02
CONCENTRATION
(continued)
137
-------
TABLE 7-9. MAIN OUTPUT FILE FOR EXAMPLE 3.
FOLLOWING GRAPHS ARE FOR THE TOP 20% OF THERESULTS
1
100 + H H H H H H- -
80
F
R
E
Q 60
U
E
N
C 40
Y
20
0 + *__ + *__ + *__ + *__ + *__ + *__ + *__ + *__ + *__ + *__ +
0.100 0.156 0.211 0.267 0.323 0.378 0.434 0.490 0.546 0.601 0.657
* 0.1E-02
CONCENTRATION
(continued)
138
-------
TABLE 7-9. MAIN OUTPUT FILE FOR EXAMPLE 3 (concluded).
1
C 100 +--
U !
M !
U !
L 80 +--
A !
T !
I !
V 60 +--
E !
F !
R 40 +--
E !
Q !
U !
E 20 +--
N !
C !
Y !
0 +**
0.100
* !
i
* i
* i
i
* i
i
i
i
i
i
* i
i
i
i
************************************************************ +
0.156 0.211 0.267 0.323 0.378 0.434 0.490 0.546 0.601 0.657
* 0.1E-02
CONCENTRATION
139
-------
TABLE 7-10. FIRST PAGE OF THE SAT1.OUT FILE FOR EXAMPLE 3.
0.47457E-03
0.47974E-03
0.48608E-03
0.48800E-03
0.49012E-03
0.49224E-03
0.49897E-03
0.49929E-03
0.49976E-03
0.50186E-03
0.50328E-03
0.50413E-03
0.50599E-03
0.50715E-03
0.50830E-03
0.50845E-03
0.50892E-03
0.50896E-03
0.50899E-03
0.50927E-03
0.50953E-03
0.51086E-03
0.51110E-03
0.51265E-03
0.51344E-03
0.51375E-03
0.51534E-03
0.51589E-03
0.51801E-03
0.51807E-03
0.51846E-03
0.52211E-03
0.52246E-03
0.52261E-03
0.52275E-03
0.52347E-03
0.52361E-03
0.52425E-03
0.52430E-03
0.52450E-03
0.52490E-03
0.52494E-03
0.52552E-03
0.52583E-03
0.52599E-03
0.52603E-03
0.52615E-03
0.52751E-03
140
-------
TABLE 7-11. STATS.OUT FILE FOR EXAMPLE 3.
Example 3 input
Subtitle D application
RESULTS
SATURATED ZONE TRANSPORT
N
MEAN
STANDARD DEVIATION
COEFFICIENT OF VARIATION =
MINIMUM VALUE
MAXIMUM VALUE
50th PERCENTILE
80th PERCENTILE
85th PERCENTILE
90th PERCENTILE
95th PERCENTILE
-999 UNABLE TO COMPUTE CONFIDENCE BOUND DUE TO INSUFFICIENT DATA
90. PERCENT CONFIDENCE INTERVAL
0
0
0
0
0
0
0
0
0
0
500
.573E
.346E
.604E
.475E
.657E
.573E
.602E
.608E
.619E
.634E
-03
-04
-01
-03
-03
-03
-03
-03
-03
-03
0
0
0
0
0
.570E
.599E
.605E
.614E
.626E
-03
-03
-03
-03
-03
0
0
0
0
0
.576E
.605E
.614E
.623E
.640E
-03
-03
-03
-03
-03
VALUE
OF TIME EQUALLED % OF TIME IN INTERVAL
OR EXCEEDED
0
0
0
0
0
0
0
0
0
0
0
. 100E-
.156E-
.211E-
.267E-
.323E-
.378E-
.434E-
.490E-
.546E-
. 601E-
.657E-
03
03
03
03
03
03
03
03
03
03
03
100.
100.
100.
100.
100.
100.
100.
99.
77.
21.
0.
.000
.000
.000
.000
.000
.000
.000
.200
.800
.000
.200
0
0
0
0
0
0
0
21
56
20
.000
.000
.000
.000
.000
.000
.800
.400
.800
.800
141
-------
APPENDIX A
CODE STRUCTURE AND INPUT DATA FORMAT
MULTIMED consists of a number of modules, the theoretical details of which are
described in Salhotra et al. (1990). It is important for the user to understand
the capabilities and limitations of these modules. However, because an
interactive preprocessor, PREMED, has been developed to create or edit input, the
average user need not understand the format of the input files or the structure
of the code. For advanced users, who wish to modify the code or to examine the
input files without the use of the preprocessor, this chapter provides an
overview of the code structure and input file format. Much of the information in
this appendix is based on material in Salhotra and Mineart (1988). No
information about the pre- and postprocessors for MULTIMED is included.
A.I MODEL STRUCTURE
The code consists of a number of subroutines. The organization of the
subroutines is shown in Figure A.I. In addition, a list of all the subroutines,
the calling subroutine/program, and a brief description of the subroutines is
included in Appendix B. Each subroutine includes several comment statements that
describe the function of the subroutine. The arguments of each subroutine are
divided into three categories: 1) arguments that are passed to the subroutine by
the calling program, 2) arguments that are modified within the subroutine, and 3)
arguments returned by the subroutine to the calling program.
A.2 INPUT AND OUTPUT FILE UNITS
To run the model, one or two input files are needed, depending on the options
selected by the user. The location of the open statements for these files, the
default unit numbers, file names, and contents are shown in Table A-l.
The model generates a number of output files. The location of the open
statements for these files, the associated default unit numbers, file names, and
a brief description are given in Table A-2.
The user specifies the name of the main output file. In deterministic mode, this
file contains an echo of the input data and the calculated contaminant
concentration(s) at the receptor(s) of interest. In Monte Carlo mode, the file
consists of an echo of input parameters, selected statistical results, and
printer plots of frequency and cumulative frequency.
Two additional types of files are also generated. These are designated as the
*.VAR and *.OUT files, where the "*" refers to a specific type of data for the
148
-------
MAIN ) ) ) ,
/) OPENF
/) SOPEN
/) COUNT
/) MODCHK +)
/) RANSET /)
/) PRTOUT) ))))))/)
/)))))))))))))))/)
/) PRTINP))0))))-
ADPRNT
PRNEMP
PRNEMP
PRINTO
PRNTVZ) )))))!
/) OUTPUT) )))))) 0)
.)
/) AQNAMS
/) ARNAMS
/) CHNAMS
/) LFNAMS
/) SONAMS
/) STNAMS
/) VFNAMS
/) VTNAMS
/) DEFAULTS
/) INITGW
/) INITAR +)
/) INITVF)))))))2)
*
+)
/)
/) INITVT)))))))3)
/)
.)
*
/) INITST)))))))))
*
/) UNCPRO)))))))))
FRQTAB
FRQPLT
+) PRINTO
I
.) PRNEMP
DISC
INITLF)))))))) LINER1
LINV)))))))))) FACTR
LAYAVE
TMGEN1
TMGEN2
TMGEN3
REOX
CALLS)))))))0) TRNLOG
/) TRANSB
/) EXPRND))))))))
/) NORMAL)))))),
/) LOGNOR) ) ) ) ) ) 2)
/) EMPCAL)))))),
EXPRN)) ,
*
ANRMRN) 1
*
UNIFRM)!
UNIFRN
Figure A.I Subroutine organization tree for MULTIMED (from Salhotra
and Mineart, 1988).
(continued)
149
-------
MAIN)))), +) ADISRD))))))0))))))))))))))))
/) BATIN))))))))3) LEFTJT *
* /) CHKEND))))))!
READ2))))))),
READ3)))))))3)
/) ARCALC
/) AIRIN))))))))))
COMRD
ICHECK
COMRD
VIRT
SIGMAZ
/)))))))))))))))<>) VFCALC))))))0)
/) PERC))))))))2)
/) LFCALC)))))))3) EVPT
* . ) RUNOFF
*
/)
WCFUN
RAPSON))))))))
FPSI1
/) GWCALC)))) 0) CONVO2))) CPCAL)0))))))))))) GW3DPT
* /) GW3DPT) , *
* /))))))))) 2)))))))) 2) GW2DFT)0) QROMB)0) TRAPZD) ,
/))))))))), -))))))))2)))))))))2)
.) GW3DPS)2) GW2DFS))))))))))))))))))))))))))))),
FUNCTI
*
/)
*
*
*
*
*
*
*
*
*
*
*
VTCALC) ) ) ) 0)
/)
/)
/)
/)
*
*
/)
•)
ADVECT
ADISPR
COEF
STEHF
SOLAY1))) EXPERF)
CONVO1) ,
SOLBT))2)))))))))3)
+)
*
.)
+)
/)
*
.">
DERFC
EXPD
/) DGAUSS
EVAL *
LAGRNG *
SOLAY1)) EXPERF)0) DERFC *
.) EXPD *
PATCH)))))0)
+) CINTER
/) CMIX
SWCALC) )))))) 3) TRANS
/) DRINK
.) FISH
.) DBK1
)))))))))
.) ERFC
Figure A.I Subroutine organization tree for MULTIMED (from Salhotra
and Mineart, 1988). (concluded)
150
-------
Table A-l. INPUT FILES NEEDED IN MULTIMED
4444444444444444444444444444444444444444444444444444444444444444444
Opened In Unit Name Description
MAIN
ADISRD
IOUT7=7
USER-SPECIFIED
IUNT28=28 FREQ.IN
Main input file. Required
to run the model .
Contains information
describing the wind-
stability joint frequency
distribution for
contaminant transport
in the air (see Section
A. 5. 9.1) .
.VAR files and a specific module for the .OUT files. The *.VAR files contain the
values of the randomly-generated variables, any derived variables used for each
Monte Carlo simulation run, and the values of any deterministic variables. The
.OUT files contain the model results for each Monte Carlo simulation. Thus, for
typical Monte Carlo simulations, these files will contain 500 to 2000 values.
Results of statistical analyses (mean, median, and percentiles) of the values in
the *.OUT files are included in the main output file and in the file STATS. OUT.
The BATCH. ECH file contains an echo of all the data in the input file and
includes any error messages generated while reading the data. Errors in reading
the data will stop execution of the program.
Two of the output files may be used with the postprocessor, POSTMED. The data in
SAT1.0UT can be used by the postprocessor to generate frequency and cumulative
frequency plots. For transient, deterministic simulations, plots of
concentration versus time can be generated by the postprocessor using data in the
main input file.
A. 3 COMMON BLOCKS AND PARAMETER STATEMENTS
Most variables are passed between subroutines through the use of common blocks.
There are a total of 54 common blocks in the model (i.e., excluding those
associated with the pre- and postprocessors) , each containing a related set of
variables. The common blocks are contained in files which are accessed by the
code during compilation through the use of INCLUDE statements located at the
beginning of each subroutine.
Parameter statements are used to define all I/O (Input/Output) unit numbers and
array dimensions in the model. Any array dimensions or I/O numbers can be
changed by assigning a new value to the variable in the appropriate parameter
statement. The entire code must be recompiled and linked if changes are made to
any parameter statement.
151
-------
TABLE A-2. OUTPUT FILES GENERATED BY MULTIMED
4444444444444444444444444444444444444444444444444444444444444444444
Opened In Unit Name Description
MAIN
SOPEN
SOPEN
SOPEN
IOUT = 1 user-specified
IUNT8 = 8 AQUIFER.VAR
IUNT13 = 13 CHEMICAL.VAR
IUNT14 = 14 SOURCE.VAR
Main output file.
Values of aquifer variables
generated for Monte Carlo
simulations.
Values of chemical variables
generated for Monte Carlo
simulations.
Values of source variables
generated for Monte Carlo
simulations.
SOPEN
SOPEN
SOPEN
SOPEN
BAT IN
SOPEN
SOPEN
IUNT15 = 15 SURFACE.VAR
IUNT16 = 16 VFLOW.VAR
IUNT17 = 17 VTRNSPT.VAR
IUNT18 = 18 AIR.VAR
BATOUT =19 BATCH.ECH
VFOUT = 20 VFLOW.OUT
VTOUT =21 VTRNSPT.OUT
Values of surface water
variables generated for Monte
Carlo simulations.
Values of unsaturated zone
material variables and
functional parameters generated
for Monte Carlo simulations.
Values of unsaturated zone
transport variables generated
for Monte Carlo simulations.
Values of Air Emissions and
Dispersion Module variables
generated for Monte Carlo
simulations.
Echo of the batch input file
and list of any errors in the
input data.
Results from the Unsaturated
Zone Flow Module.
Concentrations at the water
table computed by the
Unsaturated Zone Transport
Module.
(continued)
152
-------
TABLE A-2. OUTPUT FILES GENERATED BY MULTIMED (concluded)
4444444444444444444444444444444444444444444444444444444444444444444
Opened In Unit Name Description
SOPEN
SOPEN
SOPEN
MAIN
MAIN
SOPEN
SOPEN
SOPEN
STOUT =22 SAT.OUT
AROUT =23 AIR.OUT
STOUT2 =24 SURFACE.OUT
ISTAT =25 STATS.OUT
IUNT27 =27 SAT1.OUT
IUNT29 =29 LANDFM.VAR
IUNT30 =30 LANDFL.VAR
IUNT31 =31 LANDFH.VAR
Downgradient well
concentrations computed by
Saturated Zone Transport
Module.
Results from Air Emissions
Module and the receptor
concentrations for the Air
Dispersion Module.
Results from the Surface
Water Module.
Summary statistics of the
receptor concentrations
(groundwater, atmosphere,
surface stream).
Downgradient well
concentrations sorted in
ascending order (CDF of
concentrations).
Values of landfill material
parameters generated for
Monte Carlo simulations.
Values of liner properties
generated for Monte Carlo
simulations.
Values of hydrology para-
meters generated for Monte
Carlo simulations.
The main output contains an echo of the input data, printer plots, and
selected statistical parameters of the results of the Monte Carlo
simulations. In addition, a summary output file is created on unit ISTAT.
153
-------
A.4 STRUCTURE OF THE INPUT FILES
The overall structure of the main input file is shown in Figure A. 2. The first
two cards contain the title of the simulation. The remaining cards in the file
contain the data necessary to run MULTIMED. These data are clustered into a
number of groups, each of which contains a specific type of data that is input
using one or more DATA CARDS. The data groups are divided into subgroups, with
each subgroup containing a set of data specific to the group within which the
subgroup is located. The structure of each data group/subgroup is illustrated in
Figure A.2. In addition to the DATA CARDS, the input file contains DATA
GROUP/SUBGROUP SPECIFICATION CARDS, END CARDS, and if desired, one or more
COMMENT CARDS.
The data for the model are divided into nine major groups. These groups are
listed in Table A-3 along with the appropriate code for the GROUP SPECIFICATION
CARD. Each data group is read in as a unit, with the beginning identified by the
GROUP SPECIFICATION CARD and the end by the END CARD. The data cards are
sandwiched between these two cards. Further, the data group may contain one or
more subgroups that are also listed in Table A-3. Note that the structure of a
subgroup is exactly the same as that for a group--!.e., a subgroup is identified
by a SUBGROUP SPECIFICATION CARD and terminated by an END CARD, with the subgroup
data sandwiched between the two cards. A data file need contain only those data
groups (and subgroups within a data group) that are necessary to run the options
selected by the user.
The options selected by the user and indicated in the General Data Group will
determine which additional groups of data are necessary. For example, if the
user has specified within the General Data Group that only the Saturated Zone
Transport Module will be run, the Unsaturated Zone Flow and Transport Data Groups
(VFL, VTP) are not necessary. Also note that the structure of the input file
allows the required data groups to be arranged in any order.
A.4.1 Comment Cards
COMMENT CARDS are indicated by the presence of three asterisks, '***'. The group
Of T***T can ke input starting at any column of the card but must be the first
three non-blank characters. The COMMENT CARDS are useful for separating data
types and can be used to include other helpful comments. Note that there are no
restrictions as to the location and number of COMMENT CARDS, except that they
cannot be the first two cards in the data file.
A.4.2 Data Group/Subgroup Specification Card, End Card, and Data Cards
The DATA GROUP/SUBGROUP SPECIFICATION CARD indicates the beginning of a specific
data group and includes the Group (Subgroup) Specification Code (Table A-3) in
columns 1 to 3. For example, if the DATA GROUP SPECIFICATION CARD contains the
letters TAQUT in columns 1 to 3, it implies that the following cards, up to and
including the corresponding 'END' card, contain aquifer data.
With the exceptions discussed in Section A.5, each DATA CARD contains information
about one variable only. Typically the card will contain the variable
154
-------
Figure A.2
155
-------
Table A-3. INPUT DATA GROUPS AND SUBGROUPS IN MULTIMED
4444444444444444444444444444444444444444444444444444444444444444444
Data Group Group Specification Code
1. General Data GEN
2 . Source Data SOU
3. Landfill Data LFL
4. Chemical Data CHE
5. Unsaturated Zone Flow Data VFL
6. Unsaturated Zone Transport Data VTP
7. Aquifer Data AQU
8. Surface Water Data SUR
9. Air Emissions and Dispersion Data AIR
Subgroups Subgroup Specification Code
1. Array Data ARR
2. Empirical Distribution Data BMP
3 . Control Data CON
4. Spatial Discretization Data SPA
5. Material Property Data SAT
6. Material Specification Data MAT
7. Unsaturated Zone Moisture Data SOI
8. Unsaturated Zone Transport Properties Data TRA
9. Unsaturated Zone Time Stepping Data TIM
10. Landfill Liner Data LIN
11. Layer Identification Data LAY
12 . Hydrology Data HYD
specification index, variable name, Monte Carlo distribution type, distribution
parameters, and the upper and lower bounds of the distribution. To the extent
possible, consistent formats for the DATA CARDS have been maintained for the
different data groups.
The termination of a data group and/or a subgroup is indicated by the END CARD,
which contains the word END in the first three columns.
A. 4. 3 Specification of Parameter Values
within each group, except the General Data Group, there are a number of variables
whose value can be specified in one of three ways: 1) the variable may be
assigned a constant value, 2) the variable may be derived within the code using
functional relations- -for example, the aquifer porosity may be derived from the
particle diameter, or 3) the variable may be assigned a distribution and the
value randomly generated in the Monte Carlo simulation. The numerical codes
associated with each distribution type are listed in Table A-4. Depending on
156
-------
Table A-4. DISTRIBUTIONS AVAILABLE AND THEIR CODES
4444444444444444444444444444444444444444444444444444444444444444444
Distribution Type Distribution Code
Constant 0
Normal 1
Lognormal 2
Exponential 3
Uniform 4
LoglO Uniform 5
Empirical 6
Johnson SB 7
Gelhara 8
Derived Dispersivityb 10
Derived Variable0 -1
a Gelhar's distribution applies only to the saturated zone dispersivities .
For details, refer to Section 6.5.10.
b The derivation of the saturated zone dispersivities using distribution
code 8 is described in Section 5.5.3.5 of Salhotra et al . (1990).
c For parameters other than the spread of the source or the source
thickness (mixing zone depth), a -2 is interchangeable with a -1.
Note: The seven Monte Carlo distributions (distribution code 1-7) are
described in Section 9.4 of Salhotra et al . (1990).
the distribution selected for a particular variable, the required input data will
vary. Refer to Section 9.4 of Salhotra et al . (1990) for information about the
seven Monte Carlo distribution options. Section 5.5.3.5 of Salhotra et al .
(1990) or Section 6.5.10 of this document explain the Gelhar distribution and the
derivation of dispersivity .
A. 4. 4 The Array Subgroup
The contents and format for the Array Subgroup are shown in Table A-5. The first
card is the SUBGROUP SPECIFICATION CARD, with the code ARR in the first three
columns. This card is followed by one card for each variable in the group.
Those cards contain values/distributions, and lower and upper bounds for the
indicated variables. For example, when the ARR subgroup is included within the
Aquifer Group Data, the subgroup will contain cards describing the aquifer-
specific variables such as porosity, dispersivities, etc. The specific variables
within each group are discussed in Section A. 5. Note that the number of cards
within the Array Subgroup varies because the various groups and subgroups have
different numbers of input variables. The variable being input is identified by
the value of the Index I .
157
-------
Table A-5. CONTENTS AND FORMAT OF A TYPICAL ARRAY SUBGROUP
4444444444444444444444444444444444444444444444444444444444444444444
Card Contents Format
Al
A2
A3
Note:
"ARR"
I, NAME (I), NDSTPRM(I), ARRPRM (I , 1)
ARRPRM(I,2), BOUND (1,1), BOUND (I, 2)
A3
12, IX, A5 0 , 7X,
110, 5X, 4F10.0
"END" A3
Card/line A2 is repeated for each variable within the group.
Definition of Contents
"ARR
NAME (I)
Subgroup Specification Card indicating the start of the Array
Subgroup.
Integer which identifies the variable being input. See the
individual data group tables for the values of I for specific
variables. Note that I is not a counter.
Name of variable I. It is used to identify the variables in the
output files.
NDSTPRM(I) Integer which identifies the type of distribution used for
variable I (e.g., constant, derived, or one of the Monte Carlo
distributions). See Table A-4.
ARRPRM (1,1) Mean value for variable I.
ARRPRM (I, 2) Standard deviation for variable I.
BOUND (1,1) Minimum allowed value (lower bound) for variable I.
BOUND (I, 2) Maximum allowed value (upper bound) for variable I.
"END" End Card indicating the end of the Array Subgroup.
The value of the integer variable NDSTPRM(I) in Table A-5 indicates the type of
distribution chosen for the variable identified by the index I. The available
options and values of the integer variable NDSTPRM(I) are listed in Table A-4.
If any of the variables are specified to have an Empirical distribution
(NDSTPRM(I) = 6), then it is necessary to include the EMPIRICAL SUBGROUP, the
details of which are described in Section A. 4. 5. Note that if the variable is
specified to be a constant (NDSTPRM(I) = 0), the value input as mean for the
corresponding variable (ARRPRM (I , 1) ) is used in the simulations. The end of the
Array Subgroup is indicated by an END CARD.
A. 4. 5 The Empirical Distribution Subgroup
The contents and format for the Empirical Distribution Subgroup are shown in
Table A-6. The first card is the SUBGROUP SPECIFICATION CARD, with the code BMP
in the first three columns. The next card identifies the variable (using the
index I) that has an empirical distribution and the number of coordinates of the
empirical cumulative distribution function that are being input. A maximum of 20
coordinates can be input.
The next set of cards (two cards, if fewer than 10 coordinate pairs are input, or
four cards, if more than 10 coordinate pairs are input) contain the probabilities
158
-------
(in ascending order) and the corresponding values of the variable. Variable
values corresponding to cumulative probability values of zero and unity must be
provided. Note that all the cumulative probability coordinate values are first
input, followed by an equal number of the corresponding variable values. The
above procedure is repeated for each of the variables that have empirical
distributions. The end of the subgroup is indicated by the END CARD.
A.5 FORMAT OF THE DATA GROUPS
As was stated above, DATA CARDS 1 and 2 contain the title of the run, with a
maximum of 80 columns per card. DATA CARDS 3 through the end contain data
specific to one or more groups/subgroups. The specific formats for each data
group are described below. The data groups do not have to be input in the order
in which they are discussed. However, it is recommended that the General Data
Group be input first. An END CARD must be put at the end of the data file
following the end of the last data group.
A.5.1 General Data Group
The contents and format of the General Data Group are shown in Table A-7. This
group can contain up to six cards. The first card is the GROUP SPECIFICATION
CARD and has the code GEN in the first three columns. The second card contains
the name of the chemical being simulated. Card three contains a number of
variables that enable the user to select the model options. A schematic showing
key options pertaining to the Saturated Zone Module is indicated in Figure A.3.
If transport in a stream (Surface Water Module) is simulated, the variable XST is
the fourth card and indicates the distance from the point of groundwater plume
interception to the water supply intake. The next card, i.e. values of TPSTN(I),
is necessary only if the Saturated Zone Module is run in the unsteady state and
contains the time values at which the saturated zone results are to be computed.
The final card is the END CARD that indicates the termination of this set of
data. Table A-8 is an example of a typical General Data Group.
A.5.2 Source Data Group
The contents and format for the Source Data Group are shown in Table A-9. This
group describes the contaminant source-specific data. The first card is the
159
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Table A-6. CONTENTS AND FORMAT OF A TYPICAL EMPIRICAL DISTRIBUTION SUBGROUP
4444444444444444444444444444444444444444444444444444444444444444444
Card Contents Format
El
E2
E3
E4
E5
Note:
'BMP
ICOUNT
"BMP"
I, ICOUNT
EMPPRM(J,2,I), J= 1,1COUNT
EMPPRM(J,1,I), J= 1,1COUNT
"END"
A3
2110
10(F8.0, 2X)
10(F8.0, 2X)
A3
Card/lines E3 and E4 are repeated twice if more than 10 coordinates are
input. Card/lines E2, E3, and E4 are repeated if more than one variable
has an empirical distribution.
Definition of Contents
Subgroup Specification Card indicating the start of the Empirical
Distribution Subgroup.
Integer which identifies the variable being input. See the
individual data group tables for the values of I for specific
variables. Note that I is not a counter.
Number of coordinates of the empirical cumulative frequency
distribution.
EMPPRM(J,2,I) Cumulative probability (coordinate) values for the empirical
distribution for variable I.
EMPPRM(J,1,I) Corresponding variable values associated with the above
probabilities.
"END"
End Card indicating the end of the Empirical Distribution
Subgroup .
160
-------
Table A-7. CONTENTS AND FORMAT OF THE GENERAL DATA GROUP
4444444444444444444444444444444444444444444444444444444444444444444
Card Contents Format
Gl
G2
G3
G4
G5
G6
"GEN"
CHEMICAL
OPTION, ISOURC, OPTAIR,
RUN, MONTE, ROUTE, ISTEAD,
NT, IOPEN, IYCHK, IZCHK
PALPH, LANDF, APPTYP, COMPLETE
XST
TPSTN(I), 1=1, NT
"END"
A3
80A1
315, 5X, A13, 2X,
715, F5.0, 315
F10 . 0
10(F8.0, 2X)
A3
Definition of Contents
"GEN"
CHEMICAL
OPTION
ISOURC
OPTAIR
0
1
2
RUN
DETERMINISTIC
MONTE
MONTE
Group Specification Card indicating the start of the General Data
Group.
Name of chemical being simulated.
Integers defining which scenario to run.
Saturated Zone Transport Module only
Unsaturated and Saturated Zone Modules
Unsaturated, Saturated and Surface Water Modules
Saturated Zone and Surface Water Modules
Air Modules only
Flag indicating the type of saturated zone boundary condition.
Gaussian source
Patch source
Flag indication which air modules to run.
No air modules are run
Air Emissions Module run
Air Emissions and Air Dispersion Modules run
Flag indicating the type of run.
The number of Monte Carlo simulations to be performed.
161
-------
Table A-7. CONTENTS AND FORMAT OF THE GENERAL DATA GROUP (continued)
4444444444444444444444444444444444444444444444444444444444444444444
Definition of Contents
ROUTE Flag indicating the exposure route for the Surface Water Module.
(This parameter is ignored if not running the Surface Water
Module. )
1 Human exposure through drinking water
2 Human exposure through fish consumption
3 Exposure to aquatic organisms
ISTEAD Flag indicating unsteady- or steady-state simulation of the
unsaturated and saturated zone transport.
0 Unsteady-state
1 Steady-state
NT Number of time steps for which unsteady-state saturated zone
transport results are required.
IOPEN Integer flag indicating the information to be output.
0 Opens all *.VAR and *.OUT files
1 Opens only the main output file, STATS. OUT, and SAT1.0UT
2 Opens only the main output file and STATS. OUT
XST Instream distance between the point of groundwater loading to the
downstream water supply intake. Include only when running the
Surface Water Module.
TPSTN(I) Times at which unsteady-state transport results for the saturated
zone are required (Needed only when ISTEAD = 0) .
IYCHK Flag for rejecting well locations outside of the groundwater plume
width when in Monte Carlo mode.
0 Rejects the generated receptor well location y-coordinate value
1 Does not reject the generated y-coordinate value
IZCHK Flag for rejecting well locations outside of the groundwater plume
depth when in Monte Carlo mode.
0 Rejects the generated receptor well location z-coordinate value
1 Does not reject the generated z-coordinate value
PALPH The selected confidence level, in percent, for the four estimated
percentiles (80th, 85th, 90th, 95th) .
LANDF Flag for running the Landfill Module.
0 Do not run the Landfill Module
1 Run the Landfill Module
162
-------
Table A-7. CONTENTS AND FORMAT OF THE GENERAL DATA GROUP (concluded)
4444444444444444444444444444444444444444444444444444444444444444444
Definition of Contents
APPTYP Flag for the type of application being simulated.
1 Generic MULTIMED application
2 Subtitle D MULTIMED application
COMPLETE Flag indicating whether all the necessary input parameters have
been defined (parameter used in the preprocessor) .
0 Undefined parameters exist in the input
1 No undefined parameters exist in the input
"END" End Card indicating the end of the General Data Subgroup.
GROUP SPECIFICATION CARD, with the code SOU in the first three columns. This is
followed by the Array Subgroup, which is indicated by the SUBGROUP SPECIFICATION
CARD with the code ARR in the first three columns. Details of the Array Subgroup
were presented in Table A-5 and Section A. 4. 4. This subgroup contains an array
of information about the values and/or the distributions and lower and upper
bounds of (up to) nine source-specific variables. The variables associated with
each index I are listed in Table A-10.
If any of the variables are specified to have an empirical distribution
(NDSTPRM(I) = 6), then it is necessary to include the Empirical Distribution
Subgroup discussed in Section A. 4. 5. If none of the source-specific variables
have an empirical distribution, this subgroup is not necessary.
Of the nine variables included in this group, three can be derived. These are
the spread of input source, the length scale, and the width scale of the
facility. Thus, NDSTPRM(4), NDSTPRM(S), and NDSTPRM(9) can have values less than
zero (see Table A-4) . The methods used to derive these variables are discussed
in Section 5.5.1 of Salhotra et al . (1990) or Section 6.2 of this manual.
Note that if the user specifies LANDF=1 in the General Data Group (i.e., uses the
Landfill Module to compute infiltration) the value of infiltration specified in
the Source Data Group (Table A-10) is ignored.
An END CARD indicates the end of the Source Data Group.
A. 5. 3 Landfill Data Group
This group contains data required by the Landfill Module and consists of four
subgroups. It is required only if the infiltration is not input by the user in
the Source Data Group. The subgroups and the associated codes are listed below:
163
-------
Figure A.3
164
-------
TABLE A-8. EXAMPLE OF A TYPICAL GENERAL DATA GROUP
GENERAL DATA
*** CHEMICAL NAME FORMAT(80A1)
DEFAULT CHEMICAL
*** ISOURC ROUTE NT IYCHK PALPH APPTYP
***OPTION OPTAIR RUN MONTE ISTEAD IOPEN IZCHK LANDF COMPLETE
300 DETERMINISTIC 500 1 1 1 0 0 190.0 1 1 0
***XST
1000.00
END GENERAL
165
-------
Table A-9. CONTENTS AND FORMAT OF THE SOURCE-SPECIFIC DATA GROUP
4444444444444444444444444444444444444444444444444444444444444444444444444444
Card Contents Format
SI
A1-A3
E1-E5
S2
"SOU"
Array Subgroup
Empirical Distribution Subgroup
"END"
A3
(See Table A- 5)
(See Table A-6)
A3
Definition of Contents
"SOU"
Array Subgroup
Empirical
Distribution
Subgroup
"END"
Control Data
Layer Thickness and
Material Data
Liner Property
Data
Landfill Material
Property Data
Hydrologic Data
Group Specification Card indicating the start of the Source Data Group.
Subgroup defining the source variables.
Subgroup defining any empirical distributions.
End Card indicating the end of the Source Data Group.
Refer to Table
A-ll
A- 12
A- 13
A- 15
A-17
Specification Code
CON
LAY
LIN
SAT
HYD
The first card of this group is the GROUP SPECIFICATION CARD and includes the code LFL in the first three columns. The next card is the first subgroup
specification card and includes the appropriate code shown above. Data for each of the subgroups of the Landfill Module are described below. None of the
variables in this group can be derived (i.e., they cannot have a distribution type of -1) .
Note that some of the input units for the Landfill Module are non-metric. These data are automatically converted from the input units to the metric
system of units by the code before computations are performed.
166
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TABLE A-10. VARIABLES IN THE SOURCE-SPECIFIC ARRAY SUBGROUP
SOURCE SPECIFIC VARIABLE DATA
ARRAY VALUES
*** SOURCE SPECIFIC VARIABLES
*** VARIABLE NAME UNITS
***
1
2
3
4
5
6
7
8
9
Infiltration rate (m/yr)
Area of waste disp unit (mA2)
Duration of pulse (yr)
Spread of contaminant srce (m)
Recharge rate (m/yr)
Source decay constant (1/yr)
Init cone at landfill (mg/1)
Length scale of facility (m)
Width scale of facility (m)
DISTRIBUTION PARAMETERS
MEAN STD
0
0
0
-1
0
0
0
-1
-1
-999.
-999.
-999.
-999.
-999.
-999.
1.00
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
DEV MIN
0.100E-
0.100E-
0.100E-
0.100E-
0.100E-
O.OOOE+
O.OOOE+
0.100E-
0.100E-
LIMITS
MAX
09
01
08
08
09
00
00
08
08
0
-
-
0
0
-
-
0
0
.100E+11
999.
999.
.100E+11
.100E+11
999.
999.
.100E+11
.100E+11
END ARRAY
END SOURCE SPECIFIC VARIABLE DATA
167
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A.5.3.1 Landfill Control Data Subgroup--
Table A-ll describes the landfill control subgroup and the default values. Data
in the other subgroups vary depending on the values specified in this subgroup.
A.5.3.2 Layer Thickness and Material Data Subgroup--
Table A-12 describes the layer thickness and material data necessary for the
Landfill Module. The data consist of the layer thickness and the material number
associated with each layer. The material numbers correspond to the order in
which the material properties are read in as part of the Material Properties
Subgroup described in Section A.5.3.4.
A.5.3.3 Liner Property Data Subgroup--
Liners are low permeability sheets of rubber or plastic materials which are used
as barriers to vertical flow. A description of the liner property data can be
found in Table A-13. There should be one set of data for each liner (LFCP(4)) in
Table A-ll. These data include the liner thickness, liner hydraulic
conductivity, percent failure of the liner and the layer number containing the
liner. The variables in this subgroup are presented in Table A-14.
A.5.3.4 Landfill Material Property Data Subgroup--
The landfill can consist of a number of different materials (the number specified
by the value of LFCP(2) in Table A-ll) with different hydrogeological properties.
The properties for each of the materials are included in this subgroup. Details
of the contents and formats of this subgroup are shown in Tables A-15 and A-16.
When the landfill consists of more than one material, information about each
material is input using an Array Subgroup. These materials are subsequently
identified by the order in which the Array Subgroups appear. Thus, material
number 4 would refer to the material that has properties included in the fourth
Array Subgroup. The termination of data for each material is indicated by an END
CARD. The end of the Landfill Material Property Data Subgroup is also indicated
by an END CARD.
A.5.3.5 Hydrologic Data Subgroup--
A water balance approach is used to estimate the average infiltration rate over
the duration of an "event." An event is defined as the typical period between
the start of two sequential storms, and includes both the storm duration and the
inter-storm interval. Table A-17 describes the contents and format of the
Hydrologic Data Subgroup required to perform this balance. The hydrologic
parameters are presented in Table A-18.
A.5.4 Chemical Data Group
The contents and format of the Chemical Data Group are shown in Table A-19. The
first card is the GROUP SPECIFICATION CARD, with the code CHE in the first three
columns. The second card is the SUBGROUP SPECIFICATION CARD, with the code ARR
in the first three columns. This subgroup contains the array of information
168
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Table A-ll. CONTENTS AND FORMAT OF THE LANDFILL MODULE CONTROL DATA GROUP
4444444444444444444444444444444444444444444444444444444444444444444
Card Contents Format
VI
C02
C03
C04
"LFL"
CON
CURVE
LFCP(l)
LFCP(2)
LFCP(3)
LFCP(4)
LFCP(5)
LFCP(6)
LFCP(7)
"END
"LFL"
"CON"
CURVE, LFCP(I),1
"END"
= 1,6
A3
A3
F10.0, 6110
A3
Definition of Contents
Group Specification Card indicating the start of the Landfill
Module Data Group.
Subgroup Specification Card indication the start of the Landfill
Module Control Data Subgroup.
SCS curve number for moisture condition AMC-II.
Number of layers in the Landfill Module.
Number of different porous materials. Maximum permissible is 20.
Parameter indicating the type of relationship used for relative
permeability versus saturation.
1 van Genuchten functional parameters
2 Brooks and Corey functional parameter
Number of liners in the landfill.
Number of seasons.
Parameter indicating method for calculating evapotranspiration.
(Only one option is available in the current version of the code.)
0 Seasonal potential evapotranspiration read in
Number of the layer which is the lateral drainage layer. Enter 0
if there is no lateral drainage layer.
End Card indicating the end of the Landfill Module Control Data
Subgroup .
169
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Table A- 12. CONTENTS AND FORMAT OF THE LANDFILL MODULE LAYER THICKNESS AND
MATERIAL DATA SUBGROUP
4444444444444444444444444444444444444444444444444444444444444444444
Card Contents Format
LAI "LAY" A3
LA2 LFLAYR(I), LPROP(I) G10.0, 110
LA3 " END " A3
Note: Card/line LA2 is repeated for each layer in the Landfill Module (LFCP(l)
in Table A-ll) .
Definition of Contents
"LAY" Subgroup Specification Card indicating the start of the Landfill
Layer Thickness and Material Subgroup.
LFLAYR(I) Thickness of layer I.
LPROP(I) Material number for layer I corresponding to data read as part of
the Material Properties Subgroup (see Section A. 5. 3. 4).
"END" End Card indicating the end of this subgroup.
about the values and/or the distributions and upper and lower bounds of up to 16
chemical-specific variables. The variables being input are identified by the
value of the index I. The variables associated with each index I are shown in
Table A-20. For example, a data card with 1=6 indicates that the card contains
information about the base catalyzed hydrolysis rate constant for the chemical
being simulated.
If any of the variables are specified to have an empirical distribution
(NDSTPRM(I) = 6), then it is necessary to include the empirical distribution
subgroup, discussed in Section A. 4. 5. If none of the chemical-specific variables
have an empirical distribution, then this subgroup is not necessary.
A. 5. 5 Unsaturated Zone Flow Data Group
This group contains data required by the Unsaturated Zone Flow Module and
consists of five subgroups. The Control Data Subgroup should be the first
subgroup in the Unsaturated Zone Flow Data Group. The subgroups and the
associated codes are listed below:
170
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Table A- 13. CONTENTS AND FORMAT OF THE LANDFILL MODULE LINER PROPERTY
SUBGROUP
4444444444444444444444444444444444444444444444444444444444444444444
Card Contents Format
A3
A3
15
A3
(See Table A-5)
(See Table A-6)
A3
A3
LI
LAI
LA2
LA3
A1-A3
E1-E5
LI2
LI 3
Note:
"LIN"
"LAY"
"LIN"
"LAY"
LINER (I)
" END "
Array Subgroup
Empirical Distribution Subgroup
"END" (Material)
"END"
Cards/lines A1-A3 and E1-E5 need to be repeated for each liner (i.e.,
LFCP(4) number of times). The Empirical Distribution Subgroup is needed
only if one or more variables in the Array Subgroup has an empirical
distribution.
Definition of Contents
Subgroup Specification Card indicating the start of the Landfill
Liner Properties Data Subgroup.
Subgroup Specification Card indicating data containing layer
number associated with liner properties.
LINER (I) Layer number associated with the following data.
Array Subgroup Subgroup defining the landfill liner properties variables.
Empirical Subgroup defining any empirical distributions.
Distribution
Subgroup
"END"
"END"
End Card indicating the end of data for a liner (one such end card
is required for each liner) .
End Card indicating the end of this subgroup.
171
-------
TABLE A-14. VARIABLES IN THE LANDFILL LINER PROPERTY ARRAY SUBGROUP
ARRAY VALUES
*** LANDFILL LINER VARIABLES
VARIABLE NAME
UNITS
DISTRIBUTION
PARAMETERS
MEAN STD DEV
LIMITS
MIN MAX
1 Thickness of liner (mills)
2 Hydraulic conductivity (cm/hr)
3 Failure rate of liner (%)
END ARRAY
-999.
-999.
-999.
-999.
-999.
-999.
0.100E-08 -999.
0.100 10.0
O.OOOE+00 100.
END LINER 1
END LINER DATA
172
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Table A- 15. CONTENTS AND FORMAT OF THE LANDFILL MODULE MATERIAL PROPERTY
SUBGROUP
4444444444444444444444444444444444444444444444444444444444444444444
Card Contents Format
A3
(See Table A-5)
(See Table A-6)
A3
A3
SA1
A1-A3
E1-E5
SA2
SA3
Note:
"SAT"
Array Subgroup
Empirical Distribution Subgroup
"END" (Material)
"END"
Cards/lines A1-A3 and E1-E5 need to be repeated for each material (i.e.,
LFCP(2) number of times). The Empirical Distribution Subgroup is needed
only if one or more variables in the Array Subgroup has an empirical
distribution.
""
"SAT
Array Subgroup
Empirical
Distribution
Subgroup
"END
"END"
Definition of Contents
Subgroup Specification Card indicating the start of the
Landfill Material Data Subgroup.
Subgroup defining the landfill material variables.
Subgroup defining any empirical distributions.
End Card indicating the end of data for a material (one such
end card is required for each material) .
End Card indicating the end of this subgroup.
173
-------
TABLE A-16. VARIABLES IN THE LANDFILL MATERIAL PROPERTY ARRAY SUBGROUP
SATURATED MATERIAL PROPERTY PARAMETERS FOR LANDFILL
ARRAY VALUES
*** LANDFILL MATERIAL VARIABLES
*** VARIABLE NAME UNITS
***
1
2
3
4
5
Sat hydraulic conduct (cm/hr)
Porosity
Residual water content
Brooks and Corey exponent
ALFA coeff for landfill (I/cm)
6 BETA - Van Genuchten exponent
END ARRAY
DISTRIBUTION PARAMETERS LIMITS
MEAN STD DEV MIN MAX
0 -999.
0 -999.
0 -999.
0 -999.
0 -999.
0 -999.
-999.
-999.
-999.
-999.
-999.
-999.
0.100E-10
0.100E-08
0.100E-08
O.OOOE+00
O.OOOE+00
O.OOOE+00
0.100E+05
1.00
1.00
10.0
1.00
10.0
END MATERIAL 1
END SATURATED MATERIAL PROPERTY DATA
174
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Table A- 17. CONTENTS AND FORMAT OF THE LANDFILL MODULE HYDROLOGY SUBGROUP
4444444444444444444444444444444444444444444444444444444444444444444
Card Contents Format
HY "HYD" A3
A1-A3 Array Subgroup (See Table A- 5)
E1-E5 Empirical Distribution Subgroup (See Table A-6)
HY2 "END" (Season) A3
HY3 "END" A3
Note: Cards/lines A1-A3 and E1-E5 need to be repeated for each season (i.e., LFCP(5) number of times) . The Empirical Distribution Subgroup is
needed only if one or more variables in the Array Subgroup has an empirical distribution.
Definition of Contents
"HYD" Subgroup Specification Card indicating the start of the Landfill Hydrology Data Subgroup.
Array Subgroup Subgroup defining the landfill hydrology variables.
Empirical Subgroup defining any empirical distributions.
Distribution
Subgroup
"END" End Card indicating the end of data for a season (one such end card is required for each season) .
"END" End Card indicating the end of this subgroup.
175
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TABLE A-18. VARIABLES IN THE LANDFILL HYDROLOGY ARRAY SUBGROUP
HYDROLOGY PARAMETERS
ARRAY VALUES
*** HYDROLOGY VARIABLES
***
***
VARIABLE NAME
UNITS
DISTRIBUTION
PARAMETERS
MEAN STD DEV
LIMITS
MIN MAX
1 Precipitation (cm)
2 Duration of event (days)
3 Pan evaporation (cm)
END ARRAY
-999.
-999.
-999.
-999.
-999.
-999.
O.OOOE+00 -999.
O.OOOE+00 -999.
O.OOOE+00 -999.
END SEASON 1
END HYDROLOGY DATA
176
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Table A- 19. CONTENTS AND FORMAT OF THE CHEMICAL -SPECIFIC DATA GROUP
4444444444444444444444444444444444444444444444444444444444444444444
Card Contents Format
Cl "CHE" A3
A1-A3 Array Subgroup (See Table A-5)
E1-E5 Empirical Distribution Subgroup (See Table A-6)
C2 "END" A3
Definition of Contents
"CHE" Group Specification Card indicating the start of the
Chemical Data Group.
Array Subgroup Subgroup defining the chemical variables.
Empirical Subgroup defining any empirical distributions.
Distribution
Subgroup
"END" End Card indicating the end of the Chemical Data Group.
Subgroup Specification Code Refer to Table
Control Data CON A-21
Layer Thickness and MAT A-22
Material Data
Unsaturated Material SAT A-23
Property Data
Soil Moisture Data SOI A-25
The first card of this group is the GROUP SPECIFICATION CARD and includes the
code VFL in the first three columns. The next card is the first subgroup
specification card. Data for each of these subgroups are described below. The
end of this group is indicated by an END CARD.
A. 5. 5.1 Unsaturated Zone Flow Control Data Subgroup- -
Table A-21 describes the Unsaturated Zone Flow Control Data Subgroup parameters.
Data in the other subgroups vary depending on the options specified in the
Control Data Subgroup. The termination of this subgroup is indicated by the END
CARD.
177
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TABLE A-20. VARIABLES IN THE CHEMICAL ARRAY SUBGROUP
CHEMICAL SPECIFIC VARIABLE DATA
ARRAY VALUES
*** CHEMICAL SPECIFIC VARIABLES
*** VARIABLE NAME UNITS
***
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
Solid phase decay coeff (1/yr)
Diss phase decay coeff (1/yr)
Overall chem dcy coeff (1/yr)
Acid cataly hydrol rte(l/M-yr)
Neutral hydrol rate cons (1/yr)
Base cataly hydrol rte(l/M-yr)
Reference temperature (C)
Normalized distrib coeff (ml/g)
Distribution coefficient
Biodegrad coef (sat zone) (1/yr)
Air diffusion coeff (cm2/s)
Ref temp for air diffusion (C)
Molecular weight (g/mole)
Mole fraction of solute
Solute vapor pressure (mm Hg)
Henry^s law cons (atm-mA3/M)
Not in use
Not in use
Not in use
DISTRIBUTION PARAMETERS LIMITS
MEAN STD DEV MIN MAX
-1 -999.
-1 -999.
-1 -999.
0 -999.
0 -999.
0 -999.
0 -999.
0 -999.
-2 -999.
0 -999.
0 -999.
0 -999.
0 -999.
0 -999.
0 -999.
0 -999.
0 -999.
0 -999.
0 -999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
O.OOOE+00
O.OOOE+00
O.OOOE+00
O.OOOE+00
O.OOOE+00
O.OOOE+00
O.OOOE+00
O.OOOE+00
O.OOOE+00
O.OOOE+00
O.OOOE+00
O.OOOE+00
O.OOOE+00
0.100E-08
O.OOOE+00
0.100E-09
O.OOOE+00
O.OOOE+00
O.OOOE+00
0.100E+11
0.100E+11
0.100E+11
-999.
-999.
-999.
100.
-999.
0.100E+11
-999.
10.0
100.
-999.
1.00
100.
1.00
1.00
1.00
1.00
END ARRAY
END CHEMICAL SPECIFIC VARIABLE DATA
178
-------
Table A-21. CONTENTS AND FORMAT OF THE UNSATURATED ZONE FLOW MODULE CONTROL
DATA GROUP
4444444444444444444444444444444444444444444444444444444444444444444
Card Contents Format
VI
C02
C03
C04
"VFL"
"CON"
VFCP (I) , I
"END"
= 1,
A3
A3
5110
A3
Definition of Contents
ITVFL
CON
VFCP(l)
VFCP(2;
VFCP(3;
VFCP(4;
VFCP(Si
'END
Group Specification Card indicating the start of the Unsaturated
Zone Flow Module Data Group.
Subgroup Specification Card indicating the start of the
Unsaturated Zone Flow Module Control Data Subgroup.
Number of nodes in the Unsaturated Zone Flow Module. The value of
this parameter is currently generated in the code. Thus, the
value in the input file is ignored.
Number of different porous materials up to a maximum of 20. If
the depth of the unsaturated zone is randomly generated in Monte
Carlo mode, VFCP(2) must equal 1.
Parameter indicating the type of relationship of relative
permeability versus saturation.
van Genuchten functional parameters
Brooks and Corey functional parameter
Parameter indicating the method of generating vertical
discretization when the depth of the unsaturated zone is constant.
This parameter is ignored in the current version of the code.
Number of layers in the unsaturated flow system (up to a maximum
of 20) . If the depth of the unsaturated zone is randomly
generated in Monte Carlo mode, VFCP(5) must equal 1.)
End Card indicating the end of this subgroup.
179
-------
Note that in Monte Carlo mode, the total depth of the unsaturated zone can be
randomly generated by setting VFCP(2) and VFCP(5) to a value of one. VTCP(l) in
Table A-27 must also be set to a value of one. In other words, only one
homogeneous layer can have a Monte Carlo distribution associated with it.
A.5.5.2 Unsaturated Flow Module Layer Thickness and Material Data Subgroup--
Table A-22 describes the layer thickness and material data necessary for the
Unsaturated Zone Flow Module. The data consist of the layer thickness and the
material number associated with each layer. When only one layer is simulated,
the layer thickness is equal to the total depth of the unsaturated zone and this
parameter can have a Monte Carlo distribution assigned to it. The material
numbers correspond to the material properties which are read in using the
Material Properties Subgroup described in Section A.5.5.3.
A.5.5.3 Unsaturated Zone Flow Material Property Subgroup--
The unsaturated zone can consist of a number of different materials (the number
specified by the value of VFCP(2) in Table A-21) with different hydrogeological
properties. The properties for each of the materials are input using the Array
and Empirical Subgroups in the Unsaturated Zone Material Property Subgroup, which
is identified by the code SAT. Details of the contents and format of this
subgroup are shown in Table A-23. The variables included in this subgroup are
shown in Table A-24. Note that none of these variables can be derived (i.e.,
none have a distribution type of -1).
When the unsaturated zone consists of more than one material, information about
each material is input using an Array Subgroup. These materials are subsequently
identified by the order in which the Array Subgroups appear. Thus, the fourth
Array Subgroup (after the Subgroup Specification Card) contains information about
the properties of material number 4. The termination of data for each material
is indicated by an END CARD. The end of the unsaturated materials data is also
indicated by an END CARD.
A.5.5.4 Unsaturated Zone Flow Moisture Data Subgroup--
In order to solve the unsaturated zone flow problem, both the relationship
between the relative permeability and water content and the relationship between
pressure head and water content need to be specified for each material (refer to
Section 3 of Salhotra et al. (1990)). The information needed to describe these
relationships is provided in the Unsaturated Zone Moisture Data Subgroup,
identified by the code SOI. The contents and format of this subgroup are
described in Table A-25.
The van Genuchten parameters, alpha and beta, are required by the code to
calculate the pressure head versus water content curve. The same parameters can
be used to describe the relationship between relative permeability and water
content by setting VFCP(3) equal to one in Table A-21. However, the code
contains the option of using the Brooks and Corey relationship instead (VFCP(3)
180
-------
Table A-22. CONTENTS AND FORMAT OF THE UNSATURATED FLOW MODULE LAYER THICKNESS
AND MATERIAL DATA SUBGROUP
4444444444444444444444444444444444444444444444444444444444444444444
Card Contents Format
Ml "MAT" A3
M2 VFLAYR(I), I PROP (I) G10.0, 110
M3 "END" A3
Note: Card/line M2 is repeated for each layer in the Unsaturated Flow Module
(VFCP(5) in Table A-21) .
Definition of Contents
"MAT" Subgroup Specification Card indicating the start of the
Unsaturated Flow Module Layer Thickness and Material
Subgroup .
VFLAYR(I) Thickness of layer I.
IPROP(I) Material number for layer I corresponding to data read as
part of the Material Data Subgroup (see Section A. 5. 5. 3).
END" End Card indicating the end of this subgroup.
181
-------
Table A-23. CONTENTS AND FORMAT OF THE UNSATURATED ZONE FLOW MODULE MATERIAL
PROPERTY SUBGROUP
4444444444444444444444444444444444444444444444444444444444444444444
Card Contents Format
SA1 "SAT" A3
A1-A3 Array Subgroup (See Table A-5)
E1-E5 Empirical Distribution Subgroup (See Table A-6)
SA2 "END" (Material) A3
SA3 "END" A3
Note: Cards/lines A1-A3 and E1-E5 need to be repeated for each material.
)))))))))))))))))))))))))))
Definition of Contents
"SAT" Group Specification Card indicating the start of the
Unsaturated Zone Flow Module Material Subgroup.
Array Subgroup Subgroup defining the material property variables.
Empirical Subgroup defining any empirical distributions.
Distribution
Subgroup
"END" End Card indicating the end of data for a material (one such
end card is required for each material) .
"END" End Card indicating the end of this subgroup.
equal to 2 in Table A-21) . If the Brooks and Corey option is selected, the
exponent, n, must be specified in addition to the van Genuchten parameters.
The subgroup specification card is followed by VFCP(2) number of the Array
Subgroups, one subgroup for each material. Table A-26 presents the definitions
of the variables included in the Array Subgroup. None of the variables in this
group can be derived (i.e., none have a distribution type of -1).
Note that the data for each material are read in the same sequence as in Table A-
23. After the data for each material has been input, an END card is inserted.
Finally, the end of the subgroup is also indicated by an END CARD.
182
-------
TABLE A-24. VARIABLES IN THE UNSATURATED FLOW MATERIAL PROPERTY ARRAY SUBGROUP
SATURATED MATERIAL PROPERTY PARAMETERS
ARRAY VALUES
*** SATURATED MATERIAL VARIABLES
VARIABLE NAME
UNITS
DISTRIBUTION
PARAMETERS
MEAN STD DEV
LIMITS
MIN MAX
1 Sat hydraulic conduct (cm/hr)
2 Unsaturated zone porosity
3 Air entry pressure head (m)
4 Depth of the unsat zone (m)
END ARRAY
0 -999. -999. 0.100E-10 0.100E+05
0 -999. -999. 0.100E-08 0.990
0 -999. -999. O.OOOE+00 -999.
0 -999. -999. 0.100E-08 -999.
END MATERIAL 1
END
183
-------
Table A-25. CONTENTS AND FORMAT OF THE UNSATURATED ZONE FLOW MODULE MOISTURE
DATA SUBGROUP
4444444444444444444444444444444444444444444444444444444444444444444
Card Contents Format
SI1 "SOI" A3
A1-A3 Array Subgroup (See Table A-5)
SI2 "END" (material) A3
SI3 "END" A3
Note: Card/line A1-A3 need to be repeated for each material.
)))))))))))))))))))))))))))
Definition of Contents
"SOI" Group Specification Card indicating the start of the
Unsaturated Zone Flow Module Moisture Data Subgroup.
Array Subgroup Subgroup defining the moisture-related variables.
"END" End Card indicating the end of data for a material (one such
end card is required for each material) .
"END" End Card indicating the end of this subgroup.
A. 5. 6 Unsaturated Zone Transport Data Group
The data required for the Unsaturated Zone Transport Module are divided into two
subgroups. Each subgroup is handled in the same manner as was described for the
subgroups of the Unsaturated Zone Flow Data Group. The subgroups included in the
Unsaturated Zone Transport Data Group are:
Subgroup Specification Code Refer to Table
Control Data CON A-27
Transport Properties TRA A-28
The first card of this group is the GROUP SPECIFICATION CARD and includes the
code VTL in the first three columns. The next card is the first SUBGROUP
SPECIFICATION CARD. The contents and format of each of these subgroups are
described below. The termination of the Unsaturated Zone Data Group is indicated
by an END CARD.
184
-------
TABLE A-26. VARIABLES IN THE UNSATURATED FLOW MOISTURE DATA ARRAY SUBGROUP
SOIL MOISTURE PARAMETERS
*** FUNCTIONAL COEFFICIENTS
ARRAY VALUES
*** FUNCTIONAL COEFFICIE VARIABLES
***
***
VARIABLE NAME
UNITS
DISTRIBUTION
PARAMETERS
MEAN STD DEV
LIMITS
MIN MAX
1 Residual water content
2 Brooks and Corey exponent, EN
3 ALFA van Genuchten coefficient
4 BETA Van Genuchten coefficient
END ARRAY
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
0.100E-08 1.00
O.OOOE+00 10.0
O.OOOE+00 1.00
1.00 5.00
END MATERIAL 1
END
END UNSATURATED FLOW
185
-------
A.5.6.1 Unsaturated Zone Transport Control Data Subgroup--
The contents and format of the Control Data Subgroup are shown in Table A-27.
The Control Data Subgroup should be the first subgroup included in the
Unsaturated Zone Transport Group. Note that VTCP(l), the number of layers, is
set equal to 1 if the depth of the unsaturated zone is generated from a Monte
Carlo distribution in the Unsaturated Zone Flow Module. The end of this subgroup
data is indicated by an END CARD.
A.5.6.2 Unsaturated Zone Transport Properties Subgroup--
The contents and format of the Transport Properties subgroup are described in
Table A-28. Following the SUBGROUP SPECIFICATION CARD is one or more Array
Subgroup that contains the values of the unsaturated zone transport variables.
An Array Subgroup is required for each material layer. If any of the variables
are specified to have an empirical distribution, then it is necessary to include
the Empirical Distribution Subgroup (for details see Section A.4.5). An END CARD
is used to indicate the end of data for each layer.
The multiple layers option is available only when the depth of the unsaturated
zone is constant (i.e., not a Monte Carlo variable) in the Unsaturated Zone Flow
Module. In the event that there is more than one transport layer, the sum of the
individual layer thicknesses must equal the sum of the layer thicknesses
specified in the Unsaturated Zone Flow Module. However, note that the number of
layers and the corresponding thicknesses can differ between the two modules.
The definitions of the specific variables that comprise this subgroup are shown
in Table A-29. Of the five variables shown, only the longitudinal dispersivity
of the soil can be derived. The method by which it is derived is discussed in
Section 4.4.3.1 of Salhotra et al. (1990). An END CARD indicates the end of the
Transport Data Subgroup.
A.5.7 Aquifer Data Group
The contents and format of the Aquifer Data Group are shown in Table A-30. The
first card is the GROUP SPECIFICATION CARD, with the code AQU included in the
first three columns. Following this is an Array Subgroup, which contains
information about the values and/or distributions of up to 18 aquifer-specific
variables. The variables included in this subgroup are shown in Table A-31.
With the exception of the source thickness, the variables are used only in the
Saturated Zone Transport Module. The source thickness is used to satisfy the
mass balance between the Unsaturated Zone (or the Source when the unsaturated
zone is not simulated) and the Saturated Zone Transport Modules.
Ten of the aquifer variables can be either derived or directly input. These
variables are the particle diameter, porosity, bulk density, source thickness,
hydraulic conductivity, seepage velocity, retardation coefficient, and the
longitudinal, lateral, and vertical dispersivities. The available options and
the algorithms for each of them are explained in Section 5.5.3 of Salhotra et al.
(1990) .
186
-------
Table A-27. CONTENTS AND FORMAT OF THE UNSATURATED ZONE TRANSPORT MODULE
CONTROL DATA SUBGROUP
4444444444444444444444444444444444444444444444444444444444444444444
Card Contents Format
VI "VTL" A3
TCI "CON" A3
TC2 VTCP(I), I = 1,10 10110
TC3 WTFUN F10.0
TC4 "END" A3
Definition of Contents
"VTL" Group specification card indicating the start of the Unsaturated
Zone Transport Group.
"CON" Control card indicating the start of the Unsaturated Transport
Control Subgroup.
VTCP(l) Number of layers used to simulate transport in the unsaturated
zone (up to a maximum of 20). Note that the number of layers
specified in the Unsaturated Zone Transport Module can be
different from the number of layers specified in the Unsaturated
Flow Module. VTCP(l) must be set equal to one if the depth of the
unsaturated zone in the Unsaturated Flow Module is to be randomly
generated in Monte Carlo mode.
VTCP(2) Number of time values at which concentration in the unsaturated
zone is to be evaluated. This variable, which corresponds to the
number of control points in the convolution integral for coupling
the unsaturated and saturated zones, is not used when the model is
run in steady-state. In the current version of the preprocessor,
this value is set to 20.
VTCP(3) Dummy integer. Not used in the current version of the model.
VTCP(4) Type of scheme used to evaluate transport in the unsaturated zone.
Note that the Stehfest algorithm is recommended when the ratio of
layer thickness to longitudinal dispersivity is less than 20.
1 Stehfest numerical inversion algorithm
2 Convolution integral approach
(continued)
187
-------
Table A-27. CONTENTS AND FORMAT OF THE UNSATURATED ZONE TRANSPORT MODULE
CONTROL DATA SUBGROUP (concluded)
4444444444444444444444444444444444444444444444444444444444444444444
Definition of Contents
P(5) For VTCP(4) = 1, the number of terms governing the accuracy of the
Stehfest algorithm. It must be a positive even integer. A value
of 18 is suggested as an initial trial value.
For VTCP(4) = 2, the number of increments used in the temporal
discretization of convolution integral approach (a value of 10 is
recommended) .
VTCP(6) Number of points in the Lagrangian scheme used for interpolating
concentration values (a value of 3 is recommended) .
VTCP(7) Number of Gauss points used in Gauss-Legendre numerical
integration of the convolution values (a value of 104 is
recommended) .
VTCP(8) Number of segments for the numerical approximation of the
convolution integral (a value of 2 is recommended) .
VTCP(9) Type of source boundary condition. In the current version of the
code, the value of this parameter is automatically set in
subroutine DEFAULTS . FOR, based on the values of other input
parameters .
VTCP(IO) Parameter indicating if time values for computing concentration in
the unsaturated zone are to be generated. This variable is not
used when the model is run in steady-state. It is automatically
set to 1 (i.e., yes), the recommended value, in the current
version of the preprocessor.
WTFUN Value of weighting factor used to generate time step values for
evaluating concentration in the unsaturated zone. This variable,
which is not used when the model is run in steady-state, is
automatically set to 1.2 in the current version of the
preprocessor.
"END" End Card indicating the end of this data subgroup.
188
-------
Table A-28. CONTENTS AND FORMAT OF THE UNSATURATED ZONE TRANSPORT MODULE
PROPERTIES SUBGROUP
4444444444444444444444444444444444444444444444444444444444444444444
Card Contents Format
Tl "TRA" A3
A1-A3 Array Subgroup (See Table A-5)
E1-E5 Empirical Distribution Subgroup (See Table A-6)
T2 "END" (Layer) A3
SA3 "END" A3
Note: Cards/lines A1-A3 and E1-E5 need to be repeated for each layer.
)))))))))))))))))))))))))))
Definition of Contents
"TRA" Group Specification Card indicating the start of the
Unsaturated Zone Transport Module Data Subgroup.
Array Subgroup Subgroup defining the transport variables.
Empirical Subgroup defining any empirical distributions.
Distribution
Subgroup
"END" End Card indicating the end of data for a layer (one such
end card is required for each layer) .
"END" End Card indicating the end of this subgroup.
If any of the variables in this group are assigned an empirical distribution
(NDSTPRM(I) = 6), then it is necessary to include the Empirical Distribution
Subgroup (see Section A. 4. 5) . END CARDS are required to indicate the termination
of both the Array and the Empirical Subgroups. A final END CARD indicates the
end of the Aquifer Data Group.
A. 5. 8 Surface Water Data Group
The contents and format of the Surface Water Data Group are shown in Table A-32.
The first card is the GROUP SPECIFICATION CARD with the code SUR in the
first three columns. This is followed an Array Subgroup that contains
information about the values/distributions of 13 variables, two of which are not
used in the current version of the model (see Table A-33) . If any of these
189
-------
TABLE A-29. VARIABLES IN THE UNSATURATED TRANSPORT PROPERTIES ARRAY SUBGROUP
TRANSPORT PARAMETER
ARRAY VALUES
*** UNSATURATED TRANSPOR VARIABLES
***
***
VARIABLE NAME
UNITS
DISTRIBUTION
PARAMETERS
MEAN STD DEV
LIMITS
MIN MAX
1 Thickness of layer (m)
2 Longit disper of layer (m)
3 Percent organic matter
4 Bulk dens of soil layer (g/cc)
5 Biological decay coeff (1/yr)
END ARRAY
0
-1
0
0
0
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
0.100E-08 -999.
O.OOOE+00 0.100E+05
O.OOOE+00
0.100E-01
O.OOOE+00
100.
5.00
-999.
END LAYER 1
END UNSATURATED TRANSPORT PARAMETERS
END TRANSPORT MODEL
190
-------
Table A-30. CONTENTS AND FORMAT OF THE AQUIFER-SPECIFIC DATA GROUP
4444444444444444444444444444444444444444444444444444444444444444444
Card Contents Format
Ql "AQU" A3
A1-A3 Array Subgroup (See Table A-5)
E1-E5 Empirical Distribution Subgroup (See Table A-6)
Q2 "END" A3
Definition of Contents
"AQU" Group Specification Card indicating the start of the Aquifer
Data Group.
Array Subgroup Subgroup defining the aquifer variables.
Empirical Subgroup defining any empirical distributions.
Distribution
Subgroup
"END" End Card indicating the end of this data group.
variables are specified to have an empirical distribution, then it is necessary
to include the Empirical Distribution Subgroup. When running the Surface Water
Module, the user must chose an exposure route. Figure A. 4 shows the three
options available. The choice is specified in the General Data Group. The end
of the group is indicated by an END CARD.
A. 5. 9 Air Emissions and Dispersion Data Group
The Air Emissions and Dispersion Data Group may consist of up to three subgroups.
The Array and Empirical Subgroups are used to specify values and distributions
for air emissions and dispersion model variables. The third subgroup, the Air
Dispersion Module Control Subgroup discussed in Section A. 5. 9.1, defines control
options when the air dispersion model is used.
The first card of this group is the GROUP SPECIFICATION CARD and includes the
code AIR in the first three columns. The next set of cards, shown in Table A-34,
includes an Array Subgroup that contains information about the
values/distributions of up to 18 variables (shown in Table A-35) . Note that if
any of these variables are specified to have an empirical distribution, then it
is necessary to include the empirical subgroup.
191
-------
TABLE A-31. VARIABLES IN THE AQUIFER DATA ARRAY SUBGROUP
AQUIFER SPECIFIC VARIABLE DATA
ARRAY VALUES
*** AQUIFER SPECIFIC VARIABLES
*** VARIABLE NAME UNITS
***
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
Particle diameter (cm)
Aquifer porosity
Bulk density (g/cc)
Aquifer thickness (m)
Mixing zone depth (m)
Hydraulic conductivity (m/yr)
Hydraulic Gradient
Grndwater seep velocity (m/yr)
Retardation coefficient
Longitudinal dispersivity (m)
Transverse dispersivity (m)
Vertical dispersivity (m)
Temperature of aquifer (C)
pH
Organic carbon content (fract)
Receptor distance from site(m)
Angle off center (degree)
Well vertical distance (m)
DISTRIBUTION PARAMETERS LIMITS
MEAN STD DEV MIN MAX
0
-2
-1
0
-1
-2
0
-2
-1
0
0
0
0
0
0
0
0
0
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
0.100E-
0.100E-
0.100E-
0.100E-
0.100E-
0.100E-
0.100E-
0.100E-
1.00
0.100E-
0.100E-
0.100E-
O.OOOE+
0.300
0.100E-
1.00
O.OOOE+
O.OOOE+
08
08
01
08
08
06
07
09
02
02
02
00
05
00
00
0
0
0
0
-
0
0
0
0
0
-
-
100.
.990
5.00
.100E+
.100E+
.100E+
999.
.100E+
.100E+
.100E+
.100E+
.100E+
100.
14.0
1.00
999.
360.
999.
06
06
09
09
09
05
05
05
END ARRAY
END AQUIFER SPECIFIC VARIABLE DATA
192
-------
Table A-32. CONTENTS AND FORMAT OF THE SURFACE WATER DATA GROUP
4444444444444444444444444444444444444444444444444444444444444444444
Card Contents Format
SU1 "SUR" A3
A1-A3 Array Subgroup (See Table A-5)
E1-E5 Empirical Distribution Subgroup (See Table A-6)
SU2 "END" A3
Definition of Contents
"SUR" Group Specification Card indicating the start of the Surface
Water Data Group.
Array Subgroup Subgroup defining the surface water variables.
Empirical Subgroup defining any empirical distributions.
Distribution
Subgroup
"END" End Card indicating the end of this data group.
A. 5. 9.1 Air Dispersion Module Control Data Subgroup- -
The Control Data Subgroup is identified by a SUBGROUP SPECIFICATION CARD with the
code CON in the first three columns. The contents and format of the subgroup are
shown in Table A-36. The subgroup is required only if the air dispersion module
is used. Note that the values for wind speed and the value for FMAT are only
read when IFREQ equals 1. The available options are shown in Figure A. 5.
If the frequency-weighting approach is used to calculate long-term dispersion
(IFREQ = 1) , frequency data are read from the file FREQ.IN. The file contains
joint frequencies for all combinations of wind speed, direction, and stability.
For the usual configuration of 16 wind direction sectors, 6 wind speeds, and 6
stability classes 576 (i.e., 16 x 6 x 6) joint frequency entries are required.
Typically this joint frequency distribution is available as STAR (Stability Array
Data) summaries for airports. The general structure of the data is illustrated
in Table A-37. Since users may have this matrix of data in different formats,
MULTIMED allows some flexibility in the format. The formats for each line of
data are specified by the variable FMAT on Card AR5 (Table A-36) . The end of
this subgroup is indicated by the END CARD. The completion of the Air Emissions
and Dispersion Data Group is indicated by the END CARD.
193
-------
TABLE A-33. VARIABLES IN THE SURFACE WATER DATA ARRAY SUBGROUP
44444444444444444444444444444444444444444'
SURFACE WATER MODULE VARIABLE DATA
ARRAY VALUES
*** SURFACE WATER MODULE VARIABLES
VARIABLE NAME
1 Channel slope
2 Stream depth
3 unused at present
4 Mannings roughness
coefficient
5 Temperature of stream
6 Sediment concentration
7 Stream pH
8 Fract organic carbon in sedmt
9 Wind speed at elev z
10 Elev of wind speed measure
11 Fract of fish which is lipid
12 unused at present
13 Stream flow
END ARRAY
UNITS
(m/m)
(m)
(C)
(mg/1)
sedmt
(m/s)
ure (m)
lipid
(m*3/s)
DISTRIBUTION
MEAN
0
0
0
0
0
0
0
0
0
0
0
0
0
PARAMETERS
STD DEV
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
1
999
999
999
999
999
999
999
999
999
999
999
999
999
MIN
LIMITS
MAX
0.100E-08 -999.
0.300E-01 -999.
O.OOOE+00 O.OOOE+00
0.100E-08
0.OOOE+00
1.00
100 .
0.100E-08 -999.
0 .300
0.100E-08
0.OOOE+00
14 .0
1.00
200 .
0.100E-08 -999.
0.100E-C
1.00
O.OOOE+00 O.OOOE+00
0.100E-08 -999.
END SURFACE WATER MODULE VARIABLE DATA
194
-------
Table A-34. CONTENTS AND FORMAT OF THE AIR EMISSION AND DISPERSION DATA GROUP
4444444444444444444444444444444444444444444444444444444444444444444
Card Contents Format
AIR "AIR" A3
AR2-AR6 Air Dispersion Control Subgroup (See Table A-36)
A1-A3 Array Subgroup (See Table A-5)
E1-E5 Empirical Distribution Subgroup (See Table A-6)
AR7 "END" A3
Definition of Contents
"AIR" Group Specification Card indicating the start of the Air
Emission and Dispersion Data Group.
Array Subgroup Subgroup defining the air variables.
Empirical Subgroup defining any empirical distributions.
Distribution
Subgroup
"END" End Card indicating the end of this data group.
195
-------
TABLE A-35. VARIABLES IN THE AIR EMISSION AND DISPERSION DATA ARRAY
AIR MODULE VARIABLE DATA
ARRAY VALUES
*** AIR MODULE VARIABLES
4444444444444444444444444444444444444444444444444444444444444444444
VARIABLE NAME
UNITS
1 Depth of soil cover (cm)
2 Temper of waste disp unit (C)
3 Porosity of unit
4 Water content
5 Gamma factor
6 Mu exponent
7 Sigma exponent
8 Atmos pump correction factor
9 Empirical enhancement factor
10 5 m/s height of rise (m)
11 Decay coeff in air (sA-l)
12 Receptor dist frm landfill (m)
13 Receptor angl frm source (rad)
14 Elevation of receptor (m)
15 Mixing height (m)
16 Std dev of wind elev ang (rad)
17 Constant wind speed (m/s)
18 Constant stability condition
END ARRAY
END AIR MODULE VARIABLE DATA
MEAN
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
rRIBUTION PARAMETERS
TD DEV
999.
999.
999.
999.
999.
999.
999.
999.
999.
999.
999.
999.
999.
999.
999.
999.
999.
999.
MIN
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
-999.
LIMITS
MAX
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
.OOOE+00
196
-------
Table A-36. CONTENTS AND FORMAT OF THE AIR DISPERSION CONTROL DATA SUBGROUP
444444444444444444444444444444444444444444444444444444444444
Card Contents Format
A3
315
6F10.0
A80
A3
AR2
AR3
AR4
AR5
AR6
"CON"
ISTBL, ISIGZ, IFREQ
(U(I), I = 1,6)
FMAT
"END"
Definition of Contents
"CON" Control card indication start of the Air Dispersion Control
Subgroup (required only if air dispersion is simulated) .
ISTBL Flag indication if terrain correction is stability dependent.
0 Stability-independent terrain correction
1 Stability-dependent terrain correction
ISIGZ Flag for vertical dispersion coefficient method.
0 The Pasquill-Gif ford method
1 The turbulence-intensity method
IFREQ Flag indicating mode for calculation of oncentrations .
0 Concentrations are calculated assuming a constant wind in the
direction of the receptor
1 Wind-stability frequency-weighting approach used
U(l) Wind speeds for each wind speed class
(required only if IFREQ = 1) .
FMAT Format for the data in the file containing wind-stability
frequency data (required only if IFREQ = 1) . The general
structure of this file is illustrated in Table A-37.
"END"
End Card indicating the end of this data subgroup.
197
-------
Table A-37. GENERAL STRUCTURE OF THE WIND-STABILITY FREQUENCY FILE (FREQ.IN)
4444444444444444444444444444444444444444444444444444444444444444444
Wind Direction Sector
1
2
3
4
5
6
7
8
9
10
11
12
Frequencies
Frequencies
Frequencies
Frequencies
Frequencies
Frequencies
Frequencies
Frequencies
Frequencies
Frequencies
Frequencies
Frequencies
for
for
for
for
for
for
for
for
for
for
for
for
six
six
six
six
six
six
six
six
six
six
six
six
wind
wind
wind
wind
wind
wind
wind
wind
wind
wind
wind
wind
speed
speed
speed
speed
speed
speed
speed
speed
speed
speed
speed
speed
classes,
classes,
classes,
classes,
classes,
classes,
classes,
classes,
classes,
classes,
classes,
classes,
sector
sector
sector
sector
sector
sector
sector
sector
sector
sector
sector
sector
1,
2,
3,
4,
5,
6,
7,
8,
9,
10,
11,
12,
stability
stability
stability
stability
stability
stability
stability
stability
stability
stability
stability
stability
class
class
class
class
class
class
class
class
class
class
class
class
A
A
A
A
A
A
A
A
A
A
A
A
198
-------
APPENDIX B
SUBROUTINES INCLUDED IN MULTIMED
Subroutine Called By
Input/Output Routines
ADISRD BATIN
AIRIN
BATIN
CHKEND
COMRD
FRQPLT
FRQTAB
ICHECK
LEFTJT
MODCHK
OPENF
OUTFOR
Subroutine
PRINTO
MAIN
MAIN
BATIN, READLF
ADISRD, AIRIN
OUTFOR
OUTFOR
READZ, READ3
BATIN, READLF
PRTINP, BATIN
MAIN
MAW
exist.
MAIN
Called Bv
MAIN, PRTOUT,
PRNTVZ
standard deviation, and maximum
Description
Reads input data necessary to run the
Air Emissions Module and the Air
Dispersion Module.
Interactive preprocessor for Air
Dispersion Module.
The batch-run input processor that reads
from a user-specified file the values of
variables and parameters updated from
their default values.
Checks for the end of a data group.
Searches for data lines in input file.
Separates connects from data input
data file.
Prints a CDF and/or PDF to output file.
Prints a table of statistics to the
output file.
Separates data for connections in input
data file.
Left justifies character variables.
Flags which modules are to be run for
Monte Carlo simulations.
Opens files. Checks to see if they
Outputs single statistics, frequency
distribution tables, CDF tables, and
printer plots.
Description
Outputs the distribution type, mean,
and
PRNEMP
PRNTIN
PRNTVZ
PRTOUT, PRNTVZ
PRTINP, PRTOUT
PRTINP
minimum allowed values for all the
variables which can be generated by
Monte Carlo routines.
Prints empirical distributions to output
file.
Writes out General Data Group to the
output file.
Outputs model parameters for the
201
-------
PRTINP
PRTOUT
MAIN
MAIN
READ2 BATIN, ADISRD,
READLF
batch input preprocessor.
RE AD 3
BATIN, ADISRD,
READLF
as the batch input preprocessor.
READLF
SOPEN
BATIN
MAIN
Saturated Zone Module
DBK1 STEADY
CONV02 GWCALC
CPCAL
CONV02
Unsaturated Zone Flow and Transport
Modules to the computer-generated batch
input file.
Outputs model parameters to the
computer-generated batch input file.
Outputs Monte Carlo information to
output file.
Reads in array values as part of the
Reads in empirical distributions as part
Reads in Landfill Source Data.
Open output files containing Monte
Carlo output. These are the *.VAR and
*.OUT files.
Calculates the modified Bessel function.
Couples Unsaturated Zone and Saturated
Zone Modules using the convolution
approach.
Evaluates saturated zone concentrations
at time "T minus tau' for the
convolution integral approach.
202
-------
ERFC
Subroutine
FUNCT1
GWCALC
TRANSP
Called By
GW2DFT, QROMB,
TRAPZD
MAIN
GW2DFS
GWCALC, GW3DPS
GW2DFT
GW3DPS
GW3DPT
PATCH
QROMB
STEADY
GWCALC, CPCAL,
GW3DPT
GWCALC
GWCALC, CPCAL
MAIN
GW2DFT
PATCH
Computes the complementary error
function.
Description
Evaluates the integrand in the
analytical solution.
Main calling routine for saturated zone
model. Sudicky's analytical solution
for three-dimensional mass transport
problem with a gaussian-distributed
source.
Analytic solution to the saturated
steady-state, two-dimensional, transport
model with a continuous gaussian source
using the Gauss-Legendre quadrature
integration scheme.
Analytic solution to the saturated,
unsteady-state, two-dimensional,
transport model with a continuous
gaussian source using the Gauss-Legendre
quadrature integration scheme.
Evaluates saturated, steady-state,
three-dimensional transport from a
continuous gaussian source. Allows for
the effects of partial penetration.
Evaluates saturated, unsteady-state,
three-dimensional transport from a
continuous gaussian source. Allows for
partial penetration effects.
Solves for transport in the saturated
zone assuming a patch source.
Preforms integration using Romberg's
method of order 2K (e.g., K = 2 is
Simpson's rule).
Steady-state solution for contaminant
transport in the saturated zone when
using a patch source.
203
-------
TMGEN1
Subroutine
TMGEN2
TMGEN3
TRANSP
TRAPZD
INITVT
Called Bv
INITVT
INITVT
PATCH
QROMB
Unsaturated Zone Transport Module
ADISPR
COEF
CONV01
DERFC
DGAUSS
EVAL
VTCALC
VTCALC
VTCALC
EXPERF
SOLBT, GW2DFS,
STEADY, TRANSP
SOLBT
Evaluates times used in convolution
integral to couple the unsaturated zone
and saturated zone transport solutions
(for constant source).
Description
Evaluates times used in the convolution
integral to couple the unsaturated zone
and saturated zone transport solutions
(for pulse source).
Evaluates times used in the convolution
integral to couple the unsaturated zone
and saturated zone transport solutions
(for decaying source).
Transient solution for contaminant
transport in the saturated zone while
using a patch source.
Computes the nth stage of refinement of
an extended trapezoidal rule.
Computes concentrations based on the
steady-state, advective dispersive
equation with first order decay.
Generates coefficients of transformed
solution for each layer.
Evaluates layered unsaturated zone
transport solution by the convolution
method.
Computes complementary error function
with real arguments.
Computes the first N roots and weight
factors for the Gauss-Legendre
quadrature integration scheme.
Evaluates functional values at Gauss
integration points.
204
-------
EXPO
EXPERF
FACTR
Subroutine
LAGRNG
LAYAVE
LINV
SOLAY1
SOLBT
STEHF
VTCALC
EXPERF
SOLAY1
LINV
Called By
SOLBT
INITVT
INITVT
VTCALC, SOLBT
VTCALC, CONV01
VTCALC
MAIN
Unsaturated Zone Flow Module
FPSIl RAPSON
Computes the exponential function. Set
function to zero for agreements less
than -170.
Evaluates the product of an exponential
function and the complementary error
function with real arguments.
Function which calculates the factorial
of a number.
Description
Lagrangian interpolation scheme.
Evaluates average saturation and
porosity for each layer in the
Unsaturated Transport Module.
Evaluates coefficients for Stehfest
algorithm.
Analytical unsaturated transport
solution for the first layer.
Evaluates unsaturated zone
concentrations at the bottom of each
layer at specific time intervals.
Evaluates the inverse of the Laplace
transform for solute transport in
layered media.
The main calling routine for the
analytical solution of transport through
the unsaturated zone.
Evaluates pressure head based upon
relationship between pressure head and
hydraulic conductivity and water
content.
205
-------
RAPSON
VFCALC
WCFUN
VFCALC
MAIN
VFCALC
Air Emission and Dispersion Module
AIRDIS MAIN
ARCALC
Subroutine
SIGMAZ
VIRT
MAIN
Called By
AIRDIS
AIRDIS
Surface Water Module
CINTER SWCALC
CMIX
DRINK
FISH
REOX
SWCALC
SWCALC
SWCALC
SWCALC
INITST
MAIN
Determines pressure head corresponding
to specific flux using modified Newton-
Raphson iteration.
Main calling routine for the one-
dimensional Unsaturated Zone Flow Module.
Evaluates the water content-pressure
head relationship.
Computes the ground-level concentration
at receptors located downwind of the
landfill.
Calculates the emission rates from the
waste disposal unit to the atmosphere.
Description
Computes vertical dispersion
coefficient.
Computes effective source area and
locates the virtual source.
Computes the fraction of the steady-
state continuous mass leaching out of
the waste disposal unit that enters
the stream.
Calculates the instream dilution due to
complete near-field mixing of the
groundwater plume.
Calculates the reduction in stream
contaminant concentration due to
sedimentation in a water treatment
plant.
Calculates the bioaccumulation of toxics
in fish.
Calculates the reaeration coefficient,
using either the Owens, 0'Conner-Dobbins
or Churchill formula, depending on the
stream depth and/or velocity.
Main calling routine for Surface Water
Module.
206
-------
Landfill Source Module
DISC INITVF
EVPT
LFCALC
LINER1
LFCALC
MAIN
INITLF
Discretizes the landfill layers and
unsaturated zone layers into a one
dimensional grid for computing pressure
head.
Computes actual evapotranspiration using
a limiting soil moisture calculation.
Main calling routine for the Landfill
Module.
Computes the effective permeability of a
landfill layer with a synthetic liner.
Subroutine Called By
PERC LFCALC
RUNOFF
LFCALC
Initialization Routines
TRANS SWCALC
INITAR
MAIN
INITGW
MAIN
INITLF
INITST
INITVF
MAIN
INITVF
MAIN
Description
Computes pressure head, water content,
and saturation distribution below a
lateral drain.
Computes runoff by SCS curve number
method modified to include the soil
moisture.
Calculates the contaminant concentration
in the stream at the location of the
drinking water treatment plant intake.
Assumes first order decay.
Assigns the input values or values
generated by the Monte Carlo routines
to the variable names used in the air
emissions and dispersion models. Also
calculates coefficients needed by the
models.
Assigns the input variables or values
generated by Monte Carlo routines to the
variable names used in the saturated
zone model. Calculates aquifer,
chemical, and source constants.
Assigns the input variables or values
generated by Monte Carlo routines to the
variable modes used in the Landfill Model.
Assigns the input values or values
generated by the Monte Carlo routines to
the variable names used in the Surface
Water Module. Also calculates
coefficients needed by the module.
Assigns the input variables or values
generated by the Monte Carlo routines to
the variable names used in the
Unsaturated Flow Module. The initial
conditions and coordinate system for the
Unsaturated Flow Module are defined here.
207
-------
INITVT
MAIN
Subroutine Called By
Monte Carlo Routines
ANRMRN
LOGNOR
CALLS
COUNT
EMPCAL
NORMAL
UNCPRO
MAIN
CALLS
EXPRN
EXPRND
EXPRND
CALLS
Assigns the Unsaturated Transport input
variables or values generated by Monte
Carlo routines to their variable names.
Assigns retardation and saturation to the
appropriate transport variables.
Description
Generates a (0,1) normally distributed
random number.
Calls the prescribed random number
generator for each parameter which is
used in the Monte Carlo simulation.
Count the number of parameters which
are to be Monte Carloed.
Generates a random number from an
empirical distribution. EMPCAL
generates a uniform random number
between 0-1 and uses it to interpolate
for a value using the piecewise linear
cumulative frequency distribution input
by the user.
Generates an exponentially distributed
random number with a mean of 1.
Generates an exponentially distributed
random number with a specified mean.
208
-------
LOGNOR
CALLS
LOG10U
NORMAL
CALLS
CALLS
Generates a lognormally distributed
random number with a specified mean and
standard deviation. The input mean and
standard deviation are in arithmetic
space.
Generates uniformly distributed loglO
numbers between 0-1, then transforms
them to a range specified by the user.
Generates a (x,a)normally distributed
random number where x is the mean and a
is the standard deviation.
PRMLIS
UNCPRO
UNFRN
UNIFRM
CHMOD, AQMOD,
SOMOD, VTMOD,
VFMOD, ARMOD,
STMOD
RANSET
TRANSB
Subroutine
TRNLOG
MAIN
CALLS
Called
CALLS
By
MAIN
ANRMRN, LOG10U
UNIFRM, EXPRN
CALLS, EMPCAL
In the interactive mode, lists the
present, minimum, and maximum values
and distribution values for the user-
specified variables.
Initializes the random number generator.
Transforms a number from SB space to normal
space or from normal space to SB space.
Description
Transforms the mean and standard
deviation in the arithmetic space (original
data) to mean and standard deviation in
logarithmic (normal) space.
Generates random values for the model
parameters. It also writes to the
output file if any errors occur when
generating the random values.
Generates a (0,1) uniformly distributed
random number.
Generates a uniformly distributed random
number between a user-specified minimum
and maximum.
Subroutines to Set Default Values and Interactive Routines
AQNAMS
MAIN
Sets Aquifer Data Group variable and label
names.
ARNAMS
MAIN
Sets Air Data Group variable and label
names.
CHNAMS
MAIN
Sets Chemical Data Group variable and label
names.
DEFAULTS
MAIN
Sets special default values to lock out
certain functions.
LFNAMS
MAIN
Sets Landfill Data Group variable and label
names.
SONAMS
STNAMS
MAIN
MAIN
Sets Source Data Group variable and label
names.
Sets Surface Water Data Group variable and
label names.
209
-------
VFNAMS
MAIN
Sets Unsaturated Flow Data Group variable
and label names.
VTNAMS
MAIN
Sets Unsaturated Transport Data Group
variable and label names.
ZIPI
BAT IN
Used when reading batch files.
210
-------
.-Opening screen
ft Wl I
WELCOME TO PREMED, THE PREPROCESSOR FOR HULTIMED (version 1.0)
Type 'aOETER.1.061 for a deterministic application tutorial, or
1 eWONTE.LOG1 for a monte carlo application tutorial
Select an option?
Analyze model results
Execute MULTIMED Model
Return to operating system
-STATUS
Editing a new file
Application type: Subtitle D landfill
Scenario: Unsaturated and Saturated Zone models
-INSTRUCT-
Select an option using arrow keys
then confirm selection with the FZ key, or
Type the first letter of an option.
HelpiiE Mexttil ttatusijj Oulet»|i Xpad;Ji Crond
Figure 2.1 Preprocessor screen after installation
.-DATA UINDOU TITLE AND SCREEN MTU
.-INSTRUCTION WINDOW TITLE —
Mpcg* N«t:R Li.ft.:& Ouiet:|| Xp^fS tand. Oop. ,
DIMENSIONS : BO X 1
CONTENT : MEW OF ABBREVIATIONS FOR AVAIUBLE COMMANDS
FEATURES : COMMANDS ARE ORDERED §T EXPECTED FREQUENCY OF USE
STANDARDIZED SET OF COMMANDS AVAILABLE (SEE TABLE 3-1)
DATA UINOOU
TITLE i UP TO U CHARACTER SCREE* DESCRIPTOR
SCKEH PATHS STtlNS OF 1 -LITTER CODES SPECIFYING PATH
OF OPERATIONS (UP TO « CHARACTERS)
DIHEKSIOin ! 78 X 16 (WITHOUT ASSISTANCE INFO WINDOW)
78 H 10 (WITH ASSISTANCE INFO WINDOW!
CONTENT t PROMPTS FOR DECISIONS OR DATA. ECHOES OF
STATE OF DATA, OR RESULTS OF OPERATIONS
FEATURES : ACCOMMODATES DATA FILE OF HAXIKM
DIMENSIONS n X 50 WITH SCROLLING
DATA RANGE : LINES OF DATA CURRENTLY DISPLAYED
TITLE I HELP, COMMANDS, LIMITS, STATUS OR XPAD
DIMENSIONS ; 78 X *
CONTENT : INFORMATION PROVIDED IT PROGRAM (COMMANDS,
KELP.LINITS.STATUS) OR BY USER (XPADJ
HELP - DETAILED USER ASSISTANCE FOR SCREEN CONTENTS
COMMANDS - DEFINITIONS OF AVAILABLE COMMANDS
LIMITS - RANGE OF ACCEPTABLE VALUES
STATUS - SYSTEM STATUS INFORMATION
XPAD - USER NOTES AND REMINDERS
VERTICAL DIMENSION
INSTRUCTION HINDOW
TITLE t INSTRUCT OR ERROR
DIMENSIONS t 78 X 3
CONTENT 1 SYSTEM GENERATED INSTRUCTIONS AMD
ERROR MESSAGES
FEATURES : DIRECTS USERS TO ACCEPTABLE KEY STROKES
3.1 Screen format utilized by the pre- and postpro.
•
UELCONE TO PRENED,
Type '9DETER.LOG'
'aNONTE.LOG'
Select an option?
Analyze model results
Execute HULT1HED Model
THE PREPROCESSOR
FOR NULTIHED (version 1.0)
for e deterministic tutorial, or
for e monte carlo
mtfrnimmmm
application tutorial
Return to operating system .
Select a
then conftr
Type the
in option using arrow keys
n selection with the F2 key, or
first letter of en option.
"
Htlp:|J next:! Xpadtl Cmnd
Figure 3.2 Example of a two window, one commandline screen.
-------
^^ UELCONE TO PREKED, THE PREPROCESSOR FOR MULTIMED (version 1.0)
Type 'aDETER.LOG' for • deterministic eppllcatlon tutorial, or
'atONTE.LOG1 for a nonte carlo application tutorial
Select an option?
wumw^-™>>&**!**&
Analyze model results
Return to operating system
r-STATUS • ' '
Editing a new file
Application type: Subtitle D landfill ,
Scenario: Unaaturtted and Saturated Zone models
[INSTRUCT —
Select an option using errow keys
than confirm selection tilth the FZ key, or
Type the first letter of an option.
Help:»J «ext:|l Statue:! Ou1*t:|| Xped:ji Onnd Onpg
Figure 3
Modify de»lr«d Control Parameter*
MMAT - number of different porous materials > 1
KPROP - Van Genuchten or Brooks/Corey paranater* > ST$$li
NVFLAY - Number of physical flow layers > 1
:
Indicates the type of relationships of relative permeability
versus saturation, and pressure head versus saturation. • ••'•>
VAHGEN - van Genuchten's functional parameters to be used.
BROOKS - Brooks/Corey functional parameters to be used.
_• «
Enter data in highlighted field(s).
Use carriage return or arrow keys to enter data and move between fields.
Use 'Next' coamand to go to next screen when done entering data. ••<'
-------
Run Title (2 lines)
CASE
Run Option? DETERMINISTIC Transient or Steady-State case? STEADY-STATE
Active modules - Surface water NO Air NO
Unset, zone YES Landfill NO
Saturated zone YES
Editing tests. Inp
Application type: Subtitle D landfill
Scenario: Unsaturated and Saturated Zone models
Enter data in highlighted fleld(s).
Use carriage return or arrow keys to enter data and move between fields.
Use 'Next1 ccamand to go to next screen when done entering data.
lelp:! Next:! U.tti:|| Status:! °^««:ll Xpad:^| <*"< Oops
Figure 3.6. Example of information contained in a, STATUS assistance window.
1
Aquifer thickness (n)
Utiat is the new value? HHHi
Editing tests. Inp
Application type: Subtitle D landfill
Scenario: Unsaturated and Saturated Zone models
Invalid data Input In highlighted field.
Use 'Limits' conaand to tee acceptable range, or
'Help' coomand to see field definition.
•xt:j| Prev:f| Li»its:fJ Statu»:f| «ulet:|| Xped:|g Cond Oops
:..,-... 'it<.
WELCOME TO PREMED, THE PREPROCESSOR FOR HULTIHED (version 1.0)
Type '80ETER.LOG1 for a deterministic application tutorial, or
•MONTE. LOG1 for a monte carlo application tutorial
Select an option? '
•m*MMBS»e«Mfssss8$ESSW™sf£S8ssMsss
Analyze model results
Execute HULTIMED Model
Return to operating system
Select an option using arrow keys
then confirm (election with the F2 key, or
] Type the first letter of an option.
Help:! Mext:I| Xpad:;i Cnnd •
Figure 4.1. Opening screen of the preprocessor.
-------
1
Which Build/Modify option?
Edit ah exUting^lnput sequence Return to Opening Screen
Select *n option uiing arrow key*
then confirn selection with the F2 key, or
Type the first letter of an option.
.lp:l Next:! Xpedil Cmnd
-.'>!•
Figure 4,2 Build/Modify screen of the preprocessor.
Select a Depth and Particle Characteristics option.
R«Mrn^;, ,f« ,*^f«*yw»^»»
list current values
PArticle diameter
POrosity of aquifer
Bulk density
Depth of aquifer
Mixing zone depth
editing a new file '
Application type: Subtitle D landfill
Scenario: Unsaturated and Saturated Zone models
Select an option using arrow keys
then confirm selection with the FZ key, or
Type the first letter of an option.
-------
j-Edft (BE)
Enter data in highlighted, field(s).
Use carriage return or arrow key> to enter data and move between fields.
Use 'Next1 comand to go to next screen when done entering data.
Help:|| Next: II Prev:|| Llmit»:f<| Xped:|f Cnnd Oops
Figure 4,3. Edit screen of the preprocessor.
Uhat type of application do you want to create?
Generic
Select an option using arrow keys . , • •
then confirm selection with the fZ key, or
Type the first letter of an option.
l«xt:|| Prev:|| Xpad:^ Ond
i
Figure 4.4. Create screen of the preprocessor:
-------
>
How many Monte Carlo simulations? f|3§
How much output do you want from
each Monte Carlo run? SOME
PALPH- confidence level (in X) for
the four estimated percent) les > 90.
Editing a new file
Application type: Subtitle D landfill
Scenario: Unsaturated and Saturated Zone models
Enter data in highlighted field(s).
Use carriage return or arrow keys to enter data and move between fields.
Use 'Next' command to go to next screen when done entering data.
elp:|i Next: t-2 Prev:|l Limits:!! Status :|| Ouiet:|| Xpad:|£ Cmnd Oops
Figure 4.6. General-2 screen of the preprocessor. This screen is only
activated if the simulation is run in Monte Carlo mode.
Edit which model parameters?
Return to Bui Id screen AQuifer saturated zone parameters
Undef - list undefined data group Air air dispersion parameters
8»nlrSlillpilpl|)^Mfi:lll!^|ij source contaminant source data
surface "surf ace" water parameters Chemical properties of contaminant
Funsat unsaturated zone flow Landfill properties definition
Tunsat unsaturated zone transport
Editing a new file
Application type: Subtitle D landfill
Scenario: Unsaturated and Saturated Zone models
Select an option using arrow keys
then confirm selection with the F2 key, or
Type the first letter of an .opt ion.
Help:?? Next:!? Status:!? Quiet :?S Xpad:|$ Cmnd
Figure 4.7. The Edit screen of the preprocessor
-------
Select an Aquifer option.
Depth and particle character Ut lea of aquifer
TYpe of source for saturated zone model , ^_
Hydraulic and dispersion feTated~paramefers "" ~~
Htsc - temperature, pH, and organic carbon of aquifer
Well • well-related parameters ' ^
Tines at which to calculate concentrations ...
_._.._
Editing a new file
Application type: Subtitle D landfill
Scenario; Unsaturated and Saturated Zone models
[Select an option using arrow keys
then confirm selection with the F2 key, or
Type the first letter of an option.
elp:Pji Next: pj! Status :|$ Quiet :$8 Xpad:jf$ Grand
Figure 4.8. AQuifer screen of the preprocessor.
H
Aquifer porosity
How do you want to define this parameter?
.......
Editing a new file
Application type: Subtitle D landfill
Scenario: Unsaturated and Saturated Zone models
..,„ „, ,„
Select an option using arrow keys
then confirm selection with the F2 key, or
Type the first letter of an option.
elp:ii Next:H Prev:B Status: F7 Quiet :«i Xpad:|| Cimd
Figure 4.14. The POrosity screen of the preprocessor for a deterministic
simulation.
Figure
determ
Aquifer porosity
What is the new value? r*ri
Editing a new file
Application type: Subtitle D landfill
Enter data in highlighted fleld(s).
Use carriage return or arrow keys to enter data and move between fields.
Use 'Next1 command to go to next screen when done entering data.
lext:l>2 Prev:Pi Limits:JS Status :P Ouiet:|I Xpad:lS Cmnd Oops
4.15. Screen for specification of Aquifer porosity for
Lnistic simulation.
a
-------
,-SOurce (BESo)
Select a Source option.
List present values
Undef - list undefined param
INFU - infiltration rate
Area of waste disposal unit
Duration of pulse
SPread of contaminant source
RECharge rate
sters source decay constant
initial concentration
LEngth scale of facility
Width scale of facility
,-STATUS —
Editing a new file
Application type: Subtitle D landfill
Scenario: Unsaturated and Saturated Zone models
r-lMSTRUCT-
Select an option using arrow keys
then confirm selection with the F2 key, or
Type the first letter of an option.
Help;! Next: 12 Status:! Quiet: ft Xpadijj Cmnd
Figure 4.9. SOurce screen of the preprocessor.
-Chemical (BEC)
Select a Chemical option.
Undef "- list undefined parameters
Name - specify chemical to be modeled
Decay coefficients (solid, dissolved, overall)
Hydrol - hydrolysis rate constants and reference temperature
Coeff - various coefficients and temperature for air diffusion
Mole • molecular definitions, solute vapor pressure and Henry's constant
-STATUS — —
Editing a new file
Application type: Subtitle D landfill
Scenario: Unsaturated and Saturated Zone models
-IMSTRUCT-
Select an option using arrow keys
then confirm selection with the F2 key,
Type the first letter of an option.
Help:lit Next;|| Status:!! "uiet;*| Xpad-.ll Cmnd
Figure 4.10. Chemical screen of preprocessor.
-------
I
Figure
Select an unsaturated flow parameter option.
Undef - 1 1st undefined parameters
Control parameter
Spatial discretization parameters
Material properties
Functional coefficients
Editing a new file
Application type: Subtitle 0 landfill
Scenario: Unsaturated and Saturated Zone models
Select an option using arrow keys
then confirm selection with the F2 key, or
Type the first letter of an option.
elp:|| Next:!* Status:** Quiet:!* X pad: 19 Cmnd
4.11. Unsaturated Flow (Funsat) screen of the preproces
sor .
Select an unsaturated Transport parameter option.
|v«ur# ~fe *&«$**
Undef - list undefined parameters
Control parameter
Property parameters
Editing a new file
Application type: Subtitle 0 landfill
Scenario: Unsaturated and Saturated Zone models
Select an option using arrow keys
then confirm selection with the F2 key, or
Type the first letter of an option.
HeloiSt Next:H Status:!! Ouiet:)i Xped:)! Cmnd •'
Figure 4.12. Unsaturated Transport (Tunsat) screen of the preprocessor.
-------
r-POrosity (BEAqDPo)-
Aquifer porosity
What distribution do you want to use?
Normal
LOGNormal
Exponential
Uniforn
LOGIOuniform
EHpirlcal
Sb dfstr
Derived
,-STATUS
Editing a new file
Application type: Subtitle D landfill
Scenario: Unsaturated and Saturated Zone models
r-lNSTRUCT-
Select an option using arrow keys
then confirm selection with the F2 key, or
Type the first letter of an option.
Help:|
Prev:|
Status: I! Quiet :Jt
Xpad:|| Cimd
igure 4.16. Porosity screen of the preprocessor for a Monte Carlo
imulation.
-POrosity CBEAcpPo)—
Aquifer porosity
Parameter Ranges
Minimum?
Maximum? none
Mean?
Std Dev?
none
none
r-STATU
Editing a new file
Application type: Subtitle D landfill
Scenario: Unsaturated and Saturated Zone models
r-1 NSTRUCT — ' ~
Enter data in highlighted field(s).
Use carriage return or arrow keys to enter data and move between fields.
Use 'Next' command to go to next screen when done entering data.
Next:l3 Prev:Jl Limits:^ Status :g Quiet:& Xpad:l Cmnd Oops
Figure 4.17. Screen showing required parameters for a Lognormal
probability density distribution.
-------
-------
WELCOME TO PREMED, THE P
Type 'aDETER.LOG' for a
'5IMONTE.LOG' for a
Select an option?
Build / Modify input sequenc
Analyze model results
Return to operating system
..
Select an option using arrow keys
then confirm selection with the F2 key, or
Type the first letter of an option.
Help:! Next:! Xped:ji Cmnd
Figure 4.20. Example of a. tutorial screen.
1
Figure 4
WELCOME TO POSTMED, THE POSTPROCESSOR FOR MULTIMED (version 1.0)
Select a plot option.
Return to operating system
Specs of plot
Titles on plot
Plot make plot
Select an option using arrow »=7»
then confirm selection with the F2 key, or
Type the first letter of an option.
gext:|| Prev:|l Xpad:$! Cmnd
.21. Opening screen of the postprocessor.
-------
-------
N
How many MULT I MED runs do you want to plot? 1||
Default: 1 Minimum: 1 Maximum: 3
Enter data in highlighted field(s).
Use carriage return or arrow keys to enter data and move between fields.
Use 'Next' command to go to next screen when done entering data.
ext:|! Prev:|| Limits:!! Quiet:|| Xpad:|$ Cwnd Oops
igure 4.22. Data-1 screen of the postprpcesssor.
Figure
Name of file containing MULT I MED simulation results?
> ' v» ~ * >« , ss s* * s Y 'r«if :>/>•/• ' V* s
™, sWv>. +' 't /<^»<^Vv*m**.»* " t&t-itto ' •**> f S4>X*A*X^ >Arf** *v»* s*^»
—LIMITS • —
Any character string is acceptable.
i— INSTRUCT — — •
Enter data in highlighted field(s).
iintt fnrrinnft rf^^npn e*r Arrnu t^v^ to ^nt^r data And move between fields.
Use "Next1 command to go to next screen when done entering data.
Help:f! Next:|| Prev:|| Limits:'^ Ouiet:f| Xpad:|| Cmnd Oops
4.23. Data- 2 screen of the postprocessor.
-------
r-Specs (S)-
Type of plot
Graphics device
X Axis type
X win
X Axis type
X nun log cycles >
COMUWIV8 Character height > 0.16
DISPLAY Legend location > LR
ARITH Y Axis type > ARITH
0. Y min > 0
0.01 Y max > 100
4 Y nun log cycles > 4
,-INSTRUCT'
Enter data in highlighted field(s).
Use carriage return or arrow keys to ente'r data and move between fields.
Use 'Next1 command to go to next screen when done entering data.
Help:H Next:ll prev:H Limits:H Xpad:f$ Grand Oops
Figure 4.24. Specs screen of the postprocessor.
—Titles (T)
Main title:
Mumwai mt-JLj ,::*,:C^LT, ;* '
Y Axis label:
Cumulative Frequency
X Axis label:
Concentration
Curve labels:
1: Run 1 2: Run 2 3: Run 3
Enter data in highlighted field(s).
Use carriage return or arrow keys to enter data and move between fields.
Use 'Next' command to go to next screen when done entering data.
Next:f| Prev:|| Limits:|| xpad:l| Cmnd Oops
Figure 4.25. Titles screen of the postprocessor.
-------
•-••S *.•!•
Cen»*itr*t.im (rnQSl)
ru_iirfS> mjn
„. ai
0.
. n . fl. n . n
I *.•*!
•-••! ».»•< «.«tt *.*!• t.»IT •••IB ••••• *.*!•
HUl-TiHCP
-------
k
CURVE NUMBER:
CONC
0.55923E-05
0.10370E-04
0.12765E-04
0.19671E-04
0.21278E-04
0.21345E-04
0.21498E-04
0.25470E-04
0.29032E-04
0.324BOE-04
0.33341E-04
0.36069E-04
'Next' coomand to
ext:|| Prev:|l Xpad:! Onnd
1 Run 1
PERCENT
0.400
0.800
1.200
1.600
2.400
2.800
3.200
3.600
4.000
4.400
4.800
5.200
go' to next screen
Igure 4.28. Example of screen showing a TEXT file (corresponds to
uaulative frequency plot shown in Figure 4.26).
Collect Site-Specific
Hydrogeological Data
Determine Active Modules
in HULTIKED; Contaminant
to Be Simulated
Propose Landfill Design and
Determine Infiltration Rate
Run HDLTIMED
Calculate DAT
yes
Acceptable
Design
-------
Well Location
WASTE
FACILITY
y, = R sin
PLAN VIEW
Waste Facility
Ground Surface
wwwwvwwvw^^
SECTION VIEW
-------
100
J- 10
I
1
o .
o
0.
CO
ox
A*
.
-------
STRUCTURE OF
INPUT DATA FILE
Title Card
Continuation ot
TaieCatd
Group 1 Data
Group 2 Data
Group N Data
I
End Card
STRUCTURE OF
EACH GROUP OR SUBGROUP
Group/Subgroup
Specification Card
Data Card 1
Data Card 2
Data Card M
End Card
-------
MATH
- OPENF
- SOPEN
- COUNT
- MODCHK ,- ADPRNT
- RANSET - PRNEMP
PRINTO
•PTCTTNP i — PRTNTO
1 PRNTVZ -1
nilTPIIT i FROTAB ' — PHWEMP
1— FRQPLT
- AQNAMS
- ARNAMS
- CHNAMS
- LFNAMS
- SONAMS
- STNAMS
- VFNAMS
- VTNAMS
— DEFAULTS
- INITGW
— INITAR r- DISC
TMTT17T7 ' TNTTT F LINERl
- LAYAVE
- TMGEN2
1— TMGEN3
TMTT<;T - — - REOX
i-mrrrn TATT0 — r — TRNLOG
- TRANSB
TTYUPNn — FXPRN 1
— EMPCAL 1
m „., 1 UNJFRH—
rnrinn - — UNIFRN
-------
MAIN -i
- CHKEND
- ARCALC
1— SIGMAZ
L- RUNOFF
- GW3DPT-,
GW3DPS ' GW2DFS
- ADISPR
— COEF
— STEHF ,— DERFC
- SOLAY1 EXPERF-
*- EXPO - DGAUSS
- CONV01-, ,- EVAL
- SOLAY1 — EXPERF— ,— DERFC
L- EXPO
PATCH STEADY
1 L DBK1
' TRANS P
1— ERFC
•— C INTER
- CMIX
- DRINK
I— FISH
-------
TIME
DEPENDENCE,
STEADY STATE
UNSTEADY STATE
LOCATION OF
WELL
tVCHK.t.ttCHK.0
REJECT WELL LOCATIONS
OUTSIDE PLUME IN VERTICAL AND
TRANSVERSE DIRECTION
REJECT WELLS SCREENED
BELOW PLUME IN VERTICAL DIRECTION
REJECT WELLS OUTSIDE •
PLUME M TRANSVERSE DIRECTION
ITCHK.IICHK.I
DO NOT REJECT ANY
WELL LOCATIONS
EXPOSURE
ROUTE
ROUTED
ROUTE=3
HUMAN EXPOSURE THROUGH
DRINKING WATER
HUMAN EXPOSURETHROUGH
FISH CONSUMPTION
EXPOSURE TO AQUATIC
ORGANISMS
-------
TERRAIN
OORRECnON
STABILITY DEPENDENT
NOTSTABUTY DEPENOENT
VERTICAL
DISPERSION
CALCULATION
MEIHOO
TURBLLBCE
MTBSTTY MEIHOO
CONSTANT WIND
AND STABUTY CONDITION
RESULTS WEK3HTH) BY JONT
Fneoueccs OF WMO
AND STABILITY
-------
1
ill-:
* |3s
TS O O
?£«.«;
*|EJ*f
en
T
•
P..I,. Unconsolidoled
KOCKS deposits
' I
1
|
l'
I"
I
S
•1
s
5>
Jfj
1 |?°
!1« II
III! F
£
1
k k K K K
(darcy) (cm2) (cm/s) (mA) (gal/doy/llz)
r105 rl0's r10z rl
•I04
10s
10
ID'1
10-*
10's
ID'5
10"
ID"7
,0"
-.o-4
ID'5
to"
io-7
lO"
10"°
IO"1
io-°
io-4
lO'0
10-*
•10
• 1
10-'
•IO"
JO'3
I0's
10"
ID"7
10"
10"
io-»
IO"1
•ID-'
.o-z
ID*3
10"
10"
10"
io-7
10
10"
10-"
10'«
o-
rIO*
•10s
K)4
10s '
•10*
•10
1
•10"
10'2
ID'3
ID'4
ID"5
10"
io-7
ti Conversion Factors for Permeability
and Hydraulic Conductivity Units
Permeability, *• Hydraulic conductivity. K
cm1
cm1 |
ft: 9.29 x 10*
darcy 9.87 x I0"»
m's J.02 x IO-»
U.S-ial/day/ft-'5.42xlO-"»
(l* «1»'CV m/t ft/« U.S. Bal/Oty/fl'
1.08 x 10-> 1.01 x 10* 9.80 x 10* 3.22 x I0» 1.85 x 10«
1 9.42xlO<* 9.11 xlO> 2.99x10* 1.71 x 10>*
1.06 x IO-»« | 9.66 x 10-* 3.17 x lO'i 1.82 x 10'
I.IOxlO-* I.04xl0» 1 3.28 2.12x10*
3.35x10-' 3.15x10* 3.0SxlO-« 1 6.46 x!0«
5.83 x IO-»» 5.49 x 10-* 4.72 x 10"' 1.55 :< 10** J
•To obtain * in fi», multiply * in em* by 1.08 x 10''.
------- |