Untied States
Control Technology Center
EPA-600/8-90-085a
December 1990
&EPA
LANDFILL AIR EMISSIONS ESTIMATION MODEL
USER'S MANUAL
control ^ technology center
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EPA-600/8-90-085a
December 1990
LANDFILL AIR EMISSIONS ESTIMATION MODEL
USER'S MANUAL
by:
W. Richard Pelt II
Robert L Bass
Irene R. Kuo
A. L Blackard
Radian Corporation
Post Office Box 13000
Research Triangle Park, NC 27709
EPA Contract 684)2-4286
Work Assignment 48
Project Officer
Susan A. Thomeloe
Air and Energy Engineering Research Laboratory
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
Prepared for
U. S. Environmental Protection Agency
Office of Research and Development
Washington, O.C. 20460
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CONTROL TECHNOLOGY CENTER
Sponsored by:
Emission Standards Division
Office of Air Quality Planning and Standards
U.S.Environmental Protection Agency
Research Triangle Park, NC 27711
Air and Energy Engineering Research Laboratory
Office of Research and Development
U.S.Environmental Protection Agency
Research Triangle Park, NC 27711
Center for Environmental Research Information
Office of Research and Development
U.S.Environmental Protection Agency
Cincinnati, OH 45268
11
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PREFACE
The Control Technology Center (CTC) was established by the U.S.
Environmental Protection Agency's (EPA's) Office of Research and Development
(ORD) and Office of Air Qxiality Planning and Standards (OAQPS) to provide
technical assistance to state and local air pollution control agencies. Three
levels of assistance can be accessed through the CTC. First, a CTC HOTLINE
has been established to provide telephone assistance on matters relating to
air pollution control technology. Second, more in-depth engineering
assistance can be provided when appropriate. Third, the CTC can provide
technical guidance through publication of technical guidance documents,
development of personal computer software, and presentation of workshops on
control technology matters.
The personal computer software projects, such as this one, focus on
topics of national or regional interest that are identified through contact
with state and local agencies. In this case, the CTC became interested in
assisting state and local agencies in estimating landfill air emission rates.
This interest was prompted by numerous requests for technical assistance from
state and local agencies on how to estimate landfill air emissions and
guidance on how the gas can be collected and controlled. This interest was
also prompted by the upcoming New Source Performance Standard (NSPS) and
lll(d) Guidelines for Municipal Solid Waste Landfill Air Emissions, which are
expected to be proposed later this year.
This document is a user's guide for the program, "Landfill Air Emissions
Estimation Model." This estimation model is based on the Scholl Canyon Gas
Generation Model, which was used in the development of the soon-to-be proposed
Clean Air Act (CAA) regulations for landfills. The Scholl Canyon model is
described in Reference 26. The recommended default values provided in the
program as input variables for the Scholl Canyon Model were developed for the
draft NSPS and guidelines. These values are based on test data collected for
landfill regulation development. Development of these default values is
outlined in Reference 20. The test data are summarized in Chapter 3 of
Reference 1.
It should be noted that the default input values provided by the program
and the user's guide may be revised depending on any future information
collected by the Agency.
ill
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ABSTRACT
This document is a user's guide for a computer program entitled,
"Landfill Air Emissions Estimation Model." This manual provides step-by-step
guidance for using this program to estimate landfill air emissions. The
purpose of this program is to aid local and state agencies in estimating
landfill air emission rates for nonmethane organic compounds and individual
air toxics. This program will also be helpful to landfill owners and
operators affected by the upcoming New Source Performance Standard and
Emission Guidelines for Municipal Solid Waste Landfill Air Emissions.
The model is based on the Scholl Canyon Gas Generation Model, which was
used in the development of the soon-to-be proposed regulation for landfill air
emissions. The Scholl Canyon Model is a first order decay equation that uses
site specific characteristics for estimating the gas generation rate. In the
absence of site-specific data, the program provides conservative default
values taken from the soon-to-be proposed NSPS for new landfills and emission
guidelines for existing landfills. These default values may be revised based
upon any future information collected by the Agency.
IV
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EPA REVIEW NOTICE
This report has been reviewed by the U.S. Environmental Protection
Agency and approved for publication. Approval does not signify that the
contents necessarily reflect the views and policy of the Agency, nor does
mention of trade names or commercial products constitute endorsement or
recommendations for use.
This document is available to the public through the National Technical
Information Service, Springfield, Virginia 22161.
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Contents
Section Paj
Preface iii
Abstract iy
Figures vi
Tables vi
Terms vii
Acknowledgment viii
1.0 Introduction 1
2.0 Installation 2
Floppy Drive Installation 2
Hard Disk Installation 2
3.0 Operation 3
Running the Program 3
The Model Help System 3
Main Menu 4
Specify Study. 4
Edit Study Data '. 7
Chemical Composition 7
Air Toxics 9
Methane Rate Constant 12
Methane Generation Potential 12
Operational Data 15
Year Open/Current Year 15
Design Capacity 15
Entering Refuse in Place 15
Predicted Closure Year 15
Calculate Air Emissions 17
Display Results 17
Configure Program 21
Exit 21
4.0 References 23
APPENDIX - Example User Session 25
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Figures
Number Page
3-1 Introductory Screen 5
3-2 Main Menu 5
3-3 Specify Study Type Sub-Menu 5
3-4 Specify Study Name Entry Screens 6
3-5 Choose a Study to Edit Window 6
3-6 Edit Study Data Sub-Menu 8
3-7 Edit Chemical Composition Data Entry Screen 8
3-8 Edit Air Toxics Concentration Entry Screen 10
3-9 Warning Screen Prior to Returning Air Toxics to Their
Default Values 10
3-10 Edit Methane Generation Decay Rate Constant Sub-Menu 13
3-11 Methane Generation Rate Constant Entry Screen 13
3-12 CFR Method 2E Warning Screen 14
3-13 Calculate Methane Gas Generation Constant Data Entry Screen. 14
3-14 Methane Generation Capacity Data Entry Screen 14
3-15 Edit Refuse Data Periods Data Entry Form 16
3-16 Closure Periods Screen 16
3-17 Calculation in Progress Screen 18
3-18 Calculation Summary 18
3-19 Display Results Sub-Menu 18
3-20 Choose a Chemical to Report Screen 19
3-21 Example Graphics Display 19
3 - 22 Tabular Report Menu 20
3-23 Output Filename Entry Screen 20
3-24 Example Model Results Output 20
3-25 Edit System Configuration Screen 22
3-26 Save Study Menu 22
3-27 Exit Screen 22
Tables
Number
3-1 Format of AIRTOXIC.TXT
VI
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Terms
Term
Nonmethane Organic Compounds (NMOC)
Potential Methane Generation Capacity (Lo)
Methane Generation Rate Content (k)
Landfill Capacity
Year of Closure
Air Toxics
Definition
NMOC is specified in this
program as the fraction of
landfill gas containing
nonmethane organic compounds
expressed as hexane. This
includes air toxics and
volatile organic compounds
which are precursors of ozone.
NMOC concentration can be
measured using guidance
provided by the soon-to-be
proposed EPA Method 25C.
Value for the potential amount
of methane generated. Lo
varies by refuse type.
A constant that determines the
rate of gas generation. The
Scholl Canyon model assumes
that k prior to the peak and k
after the peak are the same.
k is a function of moisture
content, availability of
nutrients for methanogens, pH,
and temperature.
The total amount of refuse
be disposed of in the
landfill.
to
The year in which the landfill
ceases, or is expected to
cease, accepting waste.
Compounds found in landfill
gas that are classified as
toxic, such as vinyl Chloride
and benzene.
vn
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ACKNOWLEDGMENT
The author of the program was Robert Bass of Radian Corporation. Also
serving on the EPA project team were W. Fred Dimmick and Mark Najarian of the
Office of Air Quality Planning and Standards.
Vlll
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1.0 INTRODUCTION
In the past year, the Environmental Protection Agency (EPA) has
responded to over 100 requests for technical assistance from state and local
regulatory agencies on how to estimate landfill air emissions and guidance on
how gaseous emissions can be collected and controlled.
The Landfill Air Emissions Estimation Model Program is a computer
program for state and local regulatory agencies to use as a tool for
estimating landfill air emissions. This program will also be of help to
landfill owner/operators responding to the requirements resulting from the
soon-to-be proposed New Source Performance Standards (NSPS) and Emission
Guidelines for Municipal Solid Waste (MSW) Landfills. Additional information
on the model and the model inputs is provided in Chapter 3 of the Background
Information Document (BID) for Municipal Landfill Air Emissions.1 This method
for estimating landfill air emissions is based on a first order decay equation
that employs site specific characteristics such as the year the landfill
opens, the amount of refuse in place and the design capacity. The program
also suggests default values for inputs when site specific information is
unavailable.
This manual presents a reference for the features and commands for the
program. The user's guide specifically addresses the operation of the
software, and additional information concerning the development and
theoretical basis of the calculations used in the program can be found in
References 1, 24, 25, and 26. Section 2 explains the procedures for
installing the program on a personal computer. Section 3 discusses the
commands needed to use the program. An example user session is outlined in
the Appendix. This manual should be thoroughly read before using the program.
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2.0 INSTALLATION
The Landfill Air Emissions Estimation Model requires an IBM compatible
model of a personal computer running DOS 2.0 or higher. The computer must
also have at least one floppy disk drive and 512 kilobytes or more of main
system memory.
Before installing or using the program, make a backup copy of the
program and its data files (AIRTOXIC.TXT. MSHERC.COM, LANDFILL.HLP, and
LANDFILL.CFG). Store this backup copy in a safe place for use only if
something were to happen to the working copy of the program.
The program may be run either from a floppy disk or from a hard disk.
However, hard disk installation is recommended as information can be accessed
more quickly.
FLOPPY DRIVE INSTALLATION
For floppy drive use, no special installation steps are required.
Simply insert a working copy of the program diskette into the disk drive
whenever the program is to be run.
HARD DISK INSTALLATION
To install the Landfill Air Emissions Estimation Model program on a hard
disk, first create a directory by using the following command:
MD \LANDFILL
Then, copy all of the files from the program diskette to the new directory by
typing :
COPY A:*.* \LANDFILL
Finally, before trying to run the program, change to the LANDFILL directory by
typing:
CD \LANDFILL
The program may be activated from any directory on the system by specifying
the full path (i.e., c:\LANDFILL\LANDFILL) or by adding the landfill directory
to the system search path (Path - ).
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3.0 OPERATION
This section is a detailed guide to the Landfill Air Emissions
Estimation Model program. Suggestions and hints intended to help the user
take full advantage of the program also are included.
RUNNING THE PROGRAM
For most users, running the program is as simple as typing the program
name 'LANDFILL' at the DOS prompt. However, for users with HERCULES GRAPHICS
CARDS (HGC), the driver MSHERC.COM must be loaded prior to running the
program. Failure to do so will prohibit displaying graphical information with
HGC cards.
To load the MSHERC driver, type 'MSHERC' at the DOS prompt and press
[ENTER]. The message
HERCULES RESIDENT VIDEO SUPPORT ROUTINE. Section 1.11
should appear. The driver software is a terminate and stay resident (TRS)
application and need not be loaded again if DOS has continued to execute since
MSHERC was loaded. However, attempting to load MSHERC again is harmless and
will result in the message
HERCULES VIDEO SUPPORT ROUTINES are already installed
being displayed. If at any time the system requires rebooting or power is
interrupted, the MSHERC must be reloaded.
If a hardcopy of graphical information is needed, the user must activate
the graphics utility GRAPHIC.COM prior to running the program. This will
allow the user to print any graphical information from the screen to a printer
by simply pressing the print screen key.
To load the GRAPHICS utility, type 'GRAPHICS' at the DOS prompt and
press [ENTER].
To activate the Landfill Air Emissions Estimation Model program, type
LANDFILL
at the DOS prompt. If the disk directory in which the model resides is not
being occupied and the system search path (set by the PATH - command) does not
contain the directory in which the program resides, it is necessary to enter
the entire path to the program (e.g., c:\LANDFILL\LANDFILL) to activate the
program.
Once the program has been activated, the system will display an
introductory message as shown in Figure 3-1 and will pause until the user
presses any key. After pressing a key, the program will display the main menu
of choices available. The Main Menu is shown in Figure 3-2.
THE MODEL HELP SYSTEM
Help information is available for most of the menus and data entry
screens. To view the help available for a given menu, press the [Fl] key.
The help screen will display all the available information concerning that
menu or data entry screen. Help information may contain several screens of
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information and the current offset of this information is depicted by the
small arrows in the left margin. In addition to the full help screens, a
reminder of the function keys is provided at the bottom of each menu or data
entry form.
MAIN MENU
The program uses bar menus, which appear in the center of the computer
display to control the actions of the program. You may select an entry from
the menu by using the cursor motion keys ([up arrow] and [down arrow]) to
highlight the desired entry and pressing [ENTER] . After an entry has been
selected, the program will either perform some action or present another menu
of options (a sub - menu) . To exit a sub-menu and return to the previous menu,
press [ESC] .
The selections available in the Main Menu are listed below:
Descrition
Specify Study* Designates a study name to revise or create.
Edit Study Data Edits model parameters and operational data.
Calculate Air Emissions Calculates the air emissions estimates.
Display Results Prints the report of the emission estimates.
Configure Program Allows designation of the working directory.
Exit Exits the program and returns to DOS .
* A study name must be specified before any other function can by
performed.
Specify Study
This selection causes the Specify Study sub-menu to be displayed, as
shown in Figure 3-3, that lets the user choose between either naming a new
study to create or recalling an old study to update. Upon making a selection
from this sub -menu, one of the study name entry screens displayed in
Figure 3-4 will appear. A listing of the old studies on file can be viewed by
pressing [F2] . An example of this window is shown in Figure 3-5. A study can
be selected from this window by using the cursor motion keys ([up arrow] and
[down arrow]) and then pressing [ENTER] to enable the study. The user may
create a new study by typing the desired name while within the specify New
Study Name entry screen, and then simply pressing [ENTER] to return to the
main menu. The study name can be up to 8 characters in length.
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Landfill
Air Emissions
Estimation Model
Version 1.0
Figure 3-1. Introductory Screen
Main Menu
Specify Study
Edit Study Data
Calculate Air Emissions
Display Results
Configure Program
Exit
Figure 3-2. Maj.n Menu
Specify Study
New Study
Old Study
Figure 3-3. Specify Study Type Sub-Menu
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Specify New Study Name
Specify Old Study Name
Figure 3-4. Specify Study Name Entry Screens
Choose a Study to Edit
LANDFIL1
LANDFIL2
LANDFIL3
LANDFIL4
LANDFIL5
Figure 3-5. Choose a Study to Edit Window
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Edit Study Data
The Edit Study Data option causes the sub-menu shown in Figure 3-6 to
appear.
The selections available in this sub-menu are:
Command Description
Chemical Composition Edits the composition of the landfill gas.
Methane Rate Constant Edits the methane generation rate constant.
Methane Potential Edits the methane potential constant.
Operation Data Edits the landfill operational data.
Chemical Composition--
Landfill gas is generated from the anaerobic decomposition of refuse in
Municipal Solid Waste Landfills. The gas composition is typically about
50 percent methane (CH4) and 50 percent carbon dioxide (C02) with trace
amounts of nonmethane organic compounds (NMOCs) and air toxics species.
The Chemical Composition option from the Edit Study Data sub-menu
displays the landfill gas Chemical Composition data entry form as shown in
Figure 3-7. Data entry forms are used to obtain input values from the user.
A data entry form consists of several data entry fields, each of which accepts
a specific piece of information. A different field may be selected by using
the cursor motion keys ([up arrow] and [down arrow]) to highlight the desired
field. A default value may be displayed in the field, but this value may be
overwritten. Once the desired value has been entered, simply press [ENTER] to
proceed to the next field.
There are three data entry fields for the Chemical Composition data
entry form: methane, NMOC, and air toxics. The default composition for CHA
and C02 is 50 percent each. The default concentration of NMOCs is 8000 ppmv
as hexane. Additional information concerning the rationale for selecting the
default NMOC concentration, is provided in Reference 20. Concentrations at
individual NMOCs were obtained from 46 landfills for the upcoming Clean Air
Act regulations. The median non-zero values for the nine air toxics were
selected as the suggested default values. For additional information
concerning NMOC and air toxics concentration data, refer to the Background
Information Document (BID).1 The concentration of methane may be entered by
the user. The corresponding concentration of C02 will automatically be
calculated assuming that C02 is the remainder of the landfill gas. At any
point during data entry into the Chemical Composition data entry form, the
highlighted field may be returned to its default value by pressing [F2] .
Landfill gas also contains trace levels of NMOC. The NMOC concentration
determines the NMOC emission rate once the landfill gas flowrate has been
estimated. The NMOC concentration is a function of the types of refuse in the
landfill and the extent of the reactions which produce various compounds from
the anaerobic decomposition of municipal refuse. Data were collected from
emission test reports from industry, state and local regulatory agencies,
including the South Coast Air Quality Management District (SCAQMD),2'8"19 The
data from 23 landfills range from 237 to 14294 ppmv. Based on an analysis
conducted for the soon-to-be proposed regulation, the suggested default value
for NMOC is 8000 ppmv. This analysis is documented in Reference 20. This
memorandum can be found in the Public Docket, No. A-88-09. Because the NMOC
concentration does vary, collection of site-specific data using soon-to-be-
proposed EPA method 25C is encouraged.21
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Edit Study Data
Chemical Composition
Methane Rate Constant (k)
Methane Potential (Lo)
Operational Data
Previous Menu
Figure 3-6. Edit Study Data Sub-Menu
Edit Chemical Composition
jj NMOC : 8000.000000
CH : 50.000000
4
ppm Volume
% Volume
CO : 50.000000
2
% Volume
Include Individual Air Toxics : YES
Figure 3-7. Edit Chemical Composition Data Entry Screen
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Air Toxics--
Air toxics may be included in the analysis. The space bar toggles the
Include Air Toxics option within the Chemical Composition data entry form.
After the desired values have been selected from the Chemical Composition data
entry form, [F10] must be pressed in order to accept the data. If air toxics
were chosen to be included in the study, then upon accepting the data, the
data entry form shown in Figure 3-8 will appear with the list of air toxics
along with their default concentrations. As stated previously, the suggested
default concentrations for the air toxics are the median non-zero values
obtained from 46 landfills. This data was collected for the upcoming Clean
Air Act (CAA) regulations. A more complete description of the air toxics data
can be found in Chapter 3 of the Background Information Document.1 Again, the
default concentrations can be overwritten. Air toxics can be added or deleted
from this list by pressing [F5] or [F6], respectively. The default air toxics
and their concentrations can be retrieved by pressing [F2]. The warning
screen shown in Figure 3-9 will appear prior to retrieving the default air
toxics and the default concentrations. As in other data entry screens, [F10]
must be pressed for the data to be accepted. Air Toxics may be added
permanently to the default list by editing the file AIRTOXIC.TXT with a text
editor or a word processor in non-document mode. The format for entering data
into this file is shown in Table 3-1. The format consists of 30 characters
for the chemical name, 10 digits for molecular weight, and 9 digits for the
concentration. Codisposal or Superfund sites should use the upper end of the
range of air toxics concentrations. However, it is recommended that all
facilities obtain toxic composition data using EPA Method 18, which can be
found in reference 22, as previously recommended by EPA's Emissions
Measurement Branch of the Office of Air Quality Planning and Standards.
Additional information concerning Codisposal or Superfund sites is provided in
Reference 23.
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Edit Air Toxics Concentrations
Chemical
Molecular Wt. Concentration (ppm V)
Benzene
Carbon Tetrachloride
Chloroform
Ethylene Dichloride
Methylene Chloride
Perchloroethene
II Trichloroethene
IIVinyl Chloride
jj 1,1 -Dichloroethylene
78.120000
153.810000
119.380000
98.960000
84.930000
165.830000
131.290000
62.500000
96.940000
2.65
15.00
0.08242
1.85
20.00
6.82
2.02
5.61
0.292
Figure 3-8. Edit Air Toxics Concentration Entry Screen
CAUTION
The action you are taking will reset
the ENTIRE air toxics list to its
default state.
Figure 3-9.
Warning Screen Prior to Returning Air Toxics
to their Default Values
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Table 3-1. Format of AIRTOXIC.TXT
Air Toxic Chemical Molecular Wt Concentration (ppmv)
Benzene 78.12 2.65
Carbon Tetrachloride 153.81 15.00
Chloroform 119.38 0.08242
Ethylene Dichloride 98.96 1.85
Methylene Chloride 84.93 20.00
Perchloroethene 165.83 6.82
Trichloroethene 131.29 2.02
Vinyl Chloride 62.50 5.61
1,1-Dichloroethylene 96.94 0.292
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Methane Rate Constant--
This selection causes the Edit Methane Generation Rate Constant sub-menu
to appear as shown in Figure 3-10. This screen allows for the selection of
the following three methods for setting the methane generation rate constant:
Use Default Value of k (0.02 1/yr)
Supply a Value of k
Calculate a Value of k
The first option allows the use of a default k value of 0.02. Further
information is provided in the Background Information Document, Reference 1,
as well as References 24 and 25. The next option allows entry of an
alternative decay rate constant. The data entry form for this option appears
in Figure 3-11.
The third selection branches to a data entry screen allowing the entry
of parameters specific to the draft and soon-to-be proposed CFR method 2E
testing procedures. Prior to this screen, another screen will appear
informing the user that CFR method 2E testing or comparable testing must have
been performed in order to perform the calculations. This screen is shown in
Figure 3-12. If the Calculate a Value of k option is chosen, the Calculate
Methane Gas Generation Constant data entry screen, presented in Figure 3-13,
will be displayed. All of the parameters must be non-zero in order for a
value of k to be calculated. A value of k will appear once all parameters are
non-zero. The calculated value of k can be changed simply by changing one of
the input parameters and pressing [ENTER]. Again, the default values may be
overwritten and [F10] must be pressed in order to accept the value of k that
has been calculated.
The methane generation rate constant, k, determines the methane
generation rate (for each submass of refuse). The higher the value of k, the
faster the methane generation rate increases and decreases over time. The
value of k is a function of the following factors: (1) refuse moisture
content, (2) availability of the nutrients for methanogens, (3) pH, and
(4) temperature. The k values obtained from the data collected for the
upcoming CAA regulation for municipal solid waste landfill air emissions from
SCAQMD data (1982-1986), section 114 letter responses range in value from
0.003 to 0.21.1 These values were obtained from both theoretical models using
field test data as well as from actual measurements. The suggested default
value for k is 0.02, and the method for deriving this value is outlined in
Reference 20.
Methane Generation Potential--
This option allows the user to input a Methane Generation Potential
Constant(Lo). The suggested default value of 8120 ft3/Mg already in place may
be overwritten. Press [ENTER] in order to accept the chosen value. The data
entry screen for the Methane Generation Potential Constant is shown in
Figure 3-14.
The value for the Methane Generation Potential Constant(Lo) of refuse
depends only on the type of refuse present in the landfill. The higher the
cellulose content of the refuse, the higher the value of Lo. The values of
theoretical and obtainable Lo reported in Reference 22 range from 220 to 9540
ft3 CH4/Mg refuse. The default value of Lo is 8120 ft3/Mg, and the method for
deriving this value is outlined in Reference 20.
12
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Edit Methane Generation Decay Rate Constant
Use Default Value of k (0.02 yr"-l)
Supply a Value of k
Calculate a Value of k
Figure 3-10. Edit Methane Generation Decay Rate Constant Sub-Menu
Methane Generation Rate Constant
I k : 0.020000
A m
yr -1
Figure 3-11. Methane Generation Rate Constant Entry Screen
13
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To calculate a k value, you must have
performed the field tests as outlined
in Method 2E (to be proposed Fall
1990). Press ESCAPE to return to the
previous menu.
Figure 3-12. CFR Method 2E Warning Screen.
Calculate Methane Gas Generation Constant
Average Well Depth 0.000000 ft
Average Stabilized
Radius of Influence 0.000000 ft
Refuse Density 0.650000 Mg/ft"3
Fraction of
Decomposable Refuse 1.000000
Methane Generation Potential 8120.000000 ft*3/Mg
Stabilized Flow Rate 0.000000 ft"3/min
Average Age of Refuse 0.000000 yr
Calculated Value of k 0.020000
yr
Figure 3-13. Calculate Methane Gas Generation Constant Data Entry Screen
Methane Generation Capacity of Refuse
Lo : 8120.000000
3
ft /Mg
Figure 3-14. Methane Generation Capacity Data Entry Screen
14
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Operational Data--
The Operational Data selection causes the Edit Refuse Data Periods data
entry screen, presented in Figure 3-15, to appear. This data entry screen
allows the user to enter the operational history of a landfill. Data entry
occurs in two distinct parts: landfill operational parameters and specific
landfill history.
Year Open / Current Year--
Upon activation of the entry screen, the user is permitted to change the
landfill opening year and current year parameters. For a new study, the
default current year is determined from the computer system clock and the
opening year defaults to 10 years prior to that year. Both of these
parameters can be changed by the user.
Design Capacity--
Upon keying the year open and current year into the entry screen, the
design capacity of the landfill may then be entered. For a new study the
maximum capacity of the landfill is initialized to zero, and a value must be
entered before proceeding further. The value in place for an old study may be
changed in order update the study. After accepting this information by
pressing [F10] or [ENTER], the operational parameters are verified for
appropriateness. The design capacity of the landfill cannot be zero and the
operating life of the landfill must be less than the computer program memory
limitation of 300 years.
Entering Refuse in Place--
After successful validation of the landfill operating parameters, the
user will be permitted to enter the landfill history consisting of yearly
total refuse-in-place information for the years of operation. The list of
years may be scrolled up or down using the cursor motion keys ([up arrow],
[down arrow], [page up], or [page down]). Initially, all data is zero. The
user should enter the refuse-in-place for all years known. The [up arrow] key
can be used to go back to and correct previously entered values. If any value
(except the current year which cannot be zero) is zero, the program will
interpolate using surrounding values after the list is accepted. The last
value entered does not require [ENTER] to be pressed for it to be accepted.
Instead, "F10) must be present to accept all values. The list may be returned
to its all-zero state by pressing [F2].
After accepting the history data by pressing [F10] , the data will be
verified for validity. Each successive year cannot be less than the previous
year (except in the zero case, which indicates unknown data) and must always
be less than or equal to the design capacity.
Predicted Closure Year--
Successful entry of the operational data will cause the program to
determine refuse in place for all years listed as zero. The program then
determines the acceptance rate for the last one year period entered in the
history list and uses this rate to project the closure year. Finally, the
screen presented in Figure 3-16 will appear. If the landfill has not reached
the design capacity, the user will be given the choice of either accepting or
altering the calculated year of closure. If the landfill has already reached
capacity, the user will not be permitted to change the closure year.
15
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Edit Refuse Data Periods
Year Opened : 1980 || Current Year : 1990
n
Capacity : 0.000000 Mg
Year Refuse In Place (Mg)
Figure 3-15. Edit Refuse Data Periods Data Entry Form
For the period data entered,
the expected year of closure is determined
to be
1992
assuming a refuse acceptance rate of
10000.000000 Mg/year
from current year to closure year.
Figure 3-16. Closure Periods Screen
16
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If the year of closure is changed and accepted by pressing either [F10]
or [ENTER], the program will verify that the period of operation of the
landfill is less than the program limitation of 300 years. If the closure
year is valid, the program will recalculate the refuse acceptance rate
necessary to reach design capacity by the entered year of closure.
Operational data must be entered for each new study in order for calculations
to take place. If no other data is entered into the model, default parameters
will be used in the calculations. Once the operational data has been entered
and accepted by the program, the Edit Study Data menu will reappear. If all
of the study data has been entered, simply select the Previous Menu option to
return to the Main Menu.
Calculate Air Emissions
This selection from the Main Menu causes the program to perform the air
emissions calculations. While the calculations are taking place, the
Calculation in Progress screen shown in Figure 3-17 will appear. After the
calculations are complete a Calculation Summary will appear; an example
Calculation Summary is shown in Figure 3-18. Pressing any key will cause the
Main Menu to reappear.
Display Results
The Display Results selection from the Main Menu will cause the sub-menu
shown to Figure 3-19 to appear, which gives the user the option of presenting
the data in a Tabular Report or On-Screen Graphic format. If the On-Screen
Graphic option is selected and a Hercules Graphics Card is being used then
MSHERC must be activated prior to running the program. This is done by typing
MSHERC while in the sub-directory containing the program and pressing [ENTER].
Once the On-Screen Graphic option is selected, the screen shown in
Figure 3-20 will allow the user to select a chemical to view in graphic form.
An example graphics display is presented in Figure 3-21. The on-screen
graphics display may be dumped to a dot matrix printer for a hardcopy, if the
GRAPHICS.COM utility was loaded prior to running the program. Also, the
tabular report file can be imported into Lotus 1-2-3 by using the file import
function (/FIN). Some of the data at the top of the spreadsheet will appear
muddled; however, the tables of data used to generate the graphical analysis
will remain applicable, and can be used to generate Lotus graphs.
If the Tabular Report option is chosen, then the Tabular Report sub-menu
shown in Figure 3-22 will appear. This sub-menu gives the user the option of
sending the report to the screen, printer, or to a file. If the Output to
File option is chosen, the entry form shown in Figure 3-23 will appear. This
entry form lets the user enter the filename under which the report is to be
written. The file will be written to the current working directory; this can
be viewed or changed by selecting the Configure Program option from the Main
Menu. Once an option is chosen then as described before, Figure 3-20 will
appear so that a chemical for reporting can be chosen. After a selection has
been made, the report will be displayed on the screen, printed by the printer,
or written to a file. If the report will not be printed by the printer then
see the Configure Program section for details. An example report is shown in
Figure 3-24.
17
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Calculation in Progress
Current Year
Please Wait ...
Figure 3-17. Calculation in Progress Screen
Calculation Summary
Current Year Results : 1990
Maximum Year Results : 1992
Methane
Carbon Dioxide
NMOC
3.651E+002 Mg/yr
1.933E+007 Cft/yr
1.002E+003 Mg/yr
1.933E+007 Cft/yr
Methane
4.115E+002 Mg/yr ||
2.178E+007 Cft/yr ||
Carbon Dioxide : 1.129E+003 Mg/yr ||
2.178E+007 Cft/yr||
3.139E+001 Mg/yr || NMOC
3.092E+005 Cft/yr ||
3.538E+001 Mg/yr1
3.486E+005 Cft/yr ||
Figure 3-18. Calculation Summary
Display Results Menu
Tabular Report
On-screen Graphic
Previous Menu
Figure 3-19. Display Results Sub-Menu
18
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Choose a Chemical to Report
Methane
Carbon Dioxide
NMOC
Benzene
Carbon Tetrachloride
Chloroform
Ethylene Dichloride
Methylene Chloride
Figure 3-20. Choose a Chemical to Report Screen
!i
H>
t*
14.8-
13.8-
12.8-
11.8-
18.8-
9.8-
i.B-
7.8-
3.8-
4.8-
3.8-
2.8-
1.8-
8.8
Inissi«n IUt«
1980 1982 1984 198C 1981 1998 1992 1994 199f 1998 2000 2002 2004 200C 2008 2818
y»«r <• = Cunwnt V*ar>
KstiiMtvA lulsilons Pr>oJ»ct»J Iiilsslons
Figure 3-21. Example Graphics Display
19
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Tabular Report Menu
Output to Screen
Output to Printer
Output to File
Previous Menu
Figure 3-22. Tabular Report Menu
Enter Output Filename
Figure 3-23. Output Filename Entry Screen
View Model Results
Model Parameters
Lo : 8120.000000 Cft / Mg
k : 0.020000 1/yr
NMOC : 8000.000000 ppmv
Methane : 50.000000 % volume
Carbon Dioxide : 50.000000 % volume
Landfill Parameters
Year Opened : 1980 Current Year : 1990 Year Closed : 1992
Capacity : 150000.000000 Mg
Average Acceptance Rate : 13000.000000 Mg/year
Average Acceptance Rate Required from
Current Year to Closure Year : 10000.000000 Mg/year
Figure 3-24. Example Model Results Output
20
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^ Pro
The Configure Program option from the Main Menu allows the user to
select the working directory for the program and the Default Print Device.
The Edit System Configuration screen is shown in Figure 3-25. The working
directory is the directory from which all study files are loaded and save
study parameters' are placed. There are four options for the Default Print
Device: LPT1, LPT2, COM1, and COM2. A different option may be viewed by
pressing the space bar; once the desired Default Print Device is shown, simply
press [ENTER] to accept the device and return to the main menu.
Exit
The Exit program option allows the user to exit the program. Before
exiting, the user will be asked if the current study is to be saved. This
screen is shown in Figure 3-26. Next, the screen shown is Figure 3-27 will
appear asking the user if the program is to be exited.
21
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Edit System Configuration
Working Directory : C:\LANDFILL\
Default Print Device : LPT1
Figure 3-25. Edit System Configuration Screen
Do you wish to save the
current study?
Yes
No
Figure 3-26. Save Study Menu
| Do you wish to exit?
Yes
No
Figure 3-27. Exit Screen
22
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4.0 REFERENCES
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
U.S. Environmental Protection Agency. Air Emissions From Municipal
Solid Vaste Landfills. Background Information for Proposed Standards
and Guidelines. March 12, 1990. (Draft)
South Coast Air Quality Management District. Landfill Gas Emissions.
Report of the Task Force. July 1982.
SCS Engineers. Gas Emission Rates from Solid Waste Landfills. Memo to
Allen Geswein, EPA-OSW. November 17, 1986.
Pohland, F.G., and Harper, S.R. Critical Review and Summary of Leachate
and Gas Production from Landfills. EPA/600/2-86/073 (NTIS PB86-240181).
August 1986.
Blanchet, M.J. and Staff of the Pacific Gas and Electric Company.
Treatment and Utilization of Landfill Gas. Mountain View Project
Feasibility Study. EPA-530/SW-583, 1977.
Bogner, J.E. The U.S. Landfill Gas Resource: Low-cost Biogas from
Municipal Solid Vaste. Argonne National Laboratory, Argonne, IL.
Prepared by U.S. Department of Energy. January 11, 1988.
DeValle, F.B., Chian, E.S.K., and E. Hammerberg, 1978, Gas Production
from Solid Waste in Landfills, J. Environmental Engineering Division
ASCE, 104(EE3):415-432.
South Coast Air Quality Management District. Source Test Report.
85-592. El Monte, CA. December 1985.
South Coast Air Quality Management District.
84-496. El Monte, CA. October 1984.
South Coast Air Quality Management District.
85-511. El Monte, CA. November 1985.
Source Test Report.
Source Test Report.
South Coast Air Quality Management District. Source Test Report.
86-0342. El Monte, CA July 1986.
South Coast Air Quality Management District. Source Test Report.
85-102. El Monte, CA. February 1985.
South Coast Air Quality Management District. Source Test Report.
87-0391. El Monte, CA. December 1987.
South Coast Air Quality Management District. Source Test Report.
86-0220. El Monte, CA. May 1986.
South Coast Air Quality Management District. Source Test Report.
87-0110. El Monte, CA. April 1987.
South Coast Air Quality Management District. Source Test Report.
87-0318. El Monte, CA. October 1987.
South Coast Air Quality Management District. Source Test Report.
87-0329. El Monte, CA. October 1987.
23
-------
18- South Coast Air Quality Management District. Source Test Report.
87-0376. El Monte, CA. November 1987.
19. South Coast Air Quality Management District. Source Test Report.
85-461. El Monte, CA. September 1985.
20. Memorandum. Kuo, I.R., Radian Corporation, to Alice Chow, EPA.
"Rationale for Selecting Tier 1 Default Values". April 18, 1990.
Docket A-88-09.
21. Regulatory Package for New Source Performance Standards and lll(d)
Guidelines for Municipal Solid Waste Air Emissions. Public Docket No.
A-88-09.
22. Title 40 Code of Federal Regulations (CFR) Part 60, Appendix A.
23. Memorandum, Kuo, I.R., Radian Corporation, to Anne Pope, EPA. Subject:
Air Emission from Codisposal Superfund Site - Phase I. February 8,
1990.
24. Memorandum. McGuinn, Y.C., Radian Corporation, to Susan Thorneloe, EPA.
Subject: Use of Landfill Gas Generation Model to Estimate VOC Emissions
from Landfills. June 21, 1988. Docket A-88-09.
25. Memorandum. McGuinn, Y.C., Radian Corporation, to Susan Thorneloe, EPA.
Subject: Sensitivity Analysis of Landfill Gas Generation Model.
June 21, 1988. Docket A-88-09.
26. Emcon Associates. Methane Generation and Recovery from Landfills.
1982.
24
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APPENDIX
EXAMPLE USER SESSION
SCENARIO-
Landfill Design Capacity: 1,000,000 Mg
Annual Acceptance Rate: 35,000 Mg/yr from 1980 to 1990
Year Open: 1975
Refuse in place in 1980: 150,000 Mg
STEPS:
1. At the Main Menu select the Specify Study option.
2. Select New Study.
3. Enter "test" for the study name for this example.
4. Select the Edit Study Data option from the Main Menu.
5. Select Chemical Composition from the Edit Study Data sub-menu.
6. Since site-specific data on methane NMOC concentration, and toxics
concentrations are not specified for this example landfill, use the
suggested default chemical compositions provided.
7. Accept the chemical composition data by pressing F10.
8. Use the suggested default toxics concentrations provided. (For this
example it is assumed that Method 18 testing has not been done.)
9. Accept the air toxics concentrations by pressing F10.
10. Select the Methane Rate Constant (k) option from the Edit Study Data
sub-menu.
11. Since site-specific testing was not performed for this example
landfill, select the Use Default Value of k (0.02 1/yr).
12. Select the Methane Potential (Lo) option.
13. Accept the suggested default for Methane Generation Capacity
(8120 ft3/Mg).
14. Select the Operational Data option from the Edit Study Data sub-
menu.
15. Enter 1975 as the year open.
25
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16- Enter 1990 current year.
17- Enter the design capacity of 1,000,000 Mg.
18. Enter 150,000 Mg of refuse in place for 1980, and add 35,000 Mg each
year until 1990. For this example: 150,000 Mg in 1980 then an
additional 35,000 Mg each year. The refuse-in-place for 1990 will
be 500,000 Mg.
19. Accept these data by pressing F10.
20. The expected year of closure should be 2005 assuming an acceptance
rate of 33333.3 Mg/year from the current year to closing year.
21. Accept the generated year of closure and refuse acceptance rate by
pressing F10. For this example it is assumed that the year of
closure calculated was acceptable.
22. Select the Previous Menu option from the Edit Study Data sub-menu to
return to the Main Menu.
23. Select the Calculate Air Emissions option.
24. A calculation summary with the following results should appear:
Current Year Results: 1990 Maximum Year Results 2005
Methane 1.234E+003 Mg/yr Methane 2.335E+003 Mg/yr
7.120E+007 Cft/yr 1.236E+008 Cft/yr
Carbon Dioxide Carbon Dioxide
3.691E+003 Mg/yr 6.407E+003 Mg/yr
7.120E+007 Cft/yr 1.236E+008 Cft/yr
NMOC 1.156E+002 Mg/yr NMOC 2.007E+002 Mg/yr
1.139E+006 Cft/yr 1.978E+006 Cft/yr
25. Press any key to return to the Main Menu.
26. Select the Display Results option.
27. Select the Tabular Report option.
28. Select the Output to Screen option.
29. Select Benzene as a chemical to report.
30. A detailed report of benzene emissions for the study results may
then be reviewed on the computer screen. For benzene, the emissions
in the year 2015 should be 4.935 x 10'2 Mg or 5.364 x 102 cubic
feet.
26
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31. Return to the Tabular Report Menu by pressing ESC.
32. Return to the Display Results Menu by pressing ESC.
33. Return to the Main Menu by pressing ESC.
34- Select the Configure Program option.
35. Make sure the Working Directory is the desired directory to which
the study should be saved.
36. Select the Exit option.
37. Save the current study.
38. The study has been saved and the program has been exited.
39. If the study needs to be used again, then simply go into the program
and select the Old Study option under the Specify Study Type sub-
menu.
40. Now enter "test."
41. Study name "test" is now enabled and can be revised or accessed to
make new reports.
27
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TECHNICAL REPORT DATA
(Please read Inamctions on the reverse before completing!
1. REPORTNo '—'
EPA-600/8-90-085a
3. RECIPIENT'S ACCESSION NO.
4. TITLE AND SUBTITLE
Landfill Air Emissions Estimation Model User's
Manual
5. REPORT DATE
December 1990
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S) ~~~
W. R. Pelt II. R.L.Bass, I. R.Kuo, and A. L. Blackard
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Radian Corporation
P. O. Box 13000
Research Triangle Park, North Carolina 27709
10. PROGRAM ELEMENT NO.
11. CONTRACT/GRANT NO.
68-02-4286, Task 48
12. SPONSORING AGENCY NAME AND ADDRESS
EPA, Office of Research and Development
Air and Energy Engineering Research Laboratory
Research Triangle Park, North Carolina 27711
13. TYPE OF REPORT AND PERIOD COVERED
Task Final; 2-9/90
14. SPONSORING AGENCY CODE
EPA/600/13
15.SUPPLEMENTARY NOTES> AEERL grpjpct officer is SusanA. Thorneloe, Mail Drop 63. 919/
541-2709. EPA-600/8-90-085b is related disk. K
16.ABSTRACT The document is a user's guide for the computer program, Landfill Air
Emissions Estimation Model." It-provides step-by-step guidance for using the pro-
gram to estimate landfill air emissions. The purpose of this program is to aid local
and state agencies in estimating landfill air emission rates for nonmethane organic
compounds and individual air toxics. This program will also be helpful to landfill
owners and operators affected by the upcoming New Source Performance Standard
(NSPS) and Emission Guidelines for Municipal Solid Waste Landfill Air Emissions.
The model is based on the Scholl Canyon Gas Generation Model, used in the develop-
ment of the soon-to-be-proposed regulation for landfill air emissions. The Scholl
Canyon Model is a first order decay equation that uses site-specific characteristics
for estimating the gas generation rate. In the absence of site-specific data, the pro-
gram provides conservative default values from the soon-to-be-proposed NSPS for
new landfills and emission guidelines for existing landfills. These default values may
be revised based on future information collected by the Agency.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.lDENTIFIERS/OPEN ENDED TERMS
c. COS AT I Field/Group
Air Pollution Organic Compounds
Mathematical Models
Emission Toxicity
Earth Fills
Estimates
Waste Disposal
Air Pollution Control
Stationary Sources
13B 07C
12A
14G 06T
13 C
15 E
8. DISTRIBUTION STATEMENT
Release to Public
19. SECURITY CLASS (ThisReport)
Unclassified
NO. OF PAGES
36
20. SECURITY CLASS (This page)
Unclassified
22. PRICE
Form 2220-1 (9-73)
28
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