United States 

Environmental Protection 

Agency 

EPA/600/R-08-116 

September 2008 

Background Information Document 

for Updating AP42 Section 2.4 for 

Estimating Emissions from 

Municipal Solid Waste Landfills 
EPA/600/R-08-116 

September 2008 

Background Information Document for 

Updating AP42 Section 2.4 for Estimating 

Emissions from Municipal Solid Waste 

Landfills
 

Prepared by 

Eastern Research Group, Inc. 

1600 Perimeter Park Dr. 

Morrisville, NC 27560 

Contract Number: EP-C-07-015 

Work Assignment Number: 0-4 

EPA Project Officer 

Susan Thorneloe 

Air Pollution Prevention and Control Division 

National Risk Management Research Laboratory 

Research Triangle Park, NC 27711 

Office of Research and Development 

U.S. Environmental Protection Agency 

Washington, DC 20460 
Notice 

The U.S. Environmental Protection Agency (EPA) through its Office of Research and Development 

performed and managed the research described in this report. It has been subjected to the Agency‘s peer 

and administrative review and has been approved for publication as an EPA document. Any opinions 

expressed in this report are those of the author and do not, necessarily, reflect the official positions and 

policies of the EPA. Any mention of products or trade names does not constitute recommendation for use 

by the EPA. 

ii 
Abstract 

This document was prepared for U.S. EPA’s Office of Research and Development in support of EPA’s 

Office of Air Quality Planning and Standards (OAQPS). The objective is to summarize available data 

used to update emissions factors for quantifying landfill gas emissions and combustion by-products using 

more up-to-date and representative data for U.S. municipal landfills. This document provides 

background information used in developing a draft of the AP-42 section 2.4 which provides guidance for 

developing estimates of landfill gas emissions for national, regional, and state emission inventories. EPA 

OAQPS will be conducting the review of Section 2.4. Once comments are addressed, the AP-42 section 

will be updated and available through EPA’s Technology Transfer Network (TTN) Clearinghouse for 

Inventories & Emissions (http://www.epa.gov/ttn/chief/ap42/). This report is considered a stand-alone report 

providing details of available data and analysis for developing landfill gas emission factors and 

combustion by-products for a wider range of pollutants and technologies. 

The inputs that are described in this report are used in EPA’s Landfill Gas Emission Model (LandGEM) 

for developing inputs for state, regional, and national emission inventories. Data from 62 LFG emissions 

tests from landfills with waste in place on or after 1992 were used to develop updated factors for use in 

LandGEM. This document also provides updated and additional emission factors for combustion byproducts for control devices such as flares, boilers, and engines. 

Of the 293 emissions tests submitted to EPA for this update, over 200 contained inadequate 

documentation or information for use in this update. The reports that were used included LFG 

composition data and, in some cases, emissions data on LFG combustion by-products. These emissions 

tests were screened for quality and compiled to create emission factors for non-methane organic 

compounds (NMOC), as well as speciated compounds in LFG. This update expands the list of emission 

factors for LFG constituents from 44 to 167 and provides many more “A” quality rated emission factors. 

Likewise, combustion by-product emission factors for dioxins/furans were added in this update, along 

with improved ratings of the other combustion by-product emission factors as a result of the addition of 

new data. 

Updated information is provided of changes in the design and operation of U.S. MSW landfills along with 

updated statistics on the amount of waste being landfilled. Information on quantifying area source 

emissions (OTM10) is provided based on the use of Optical Remote Sensing technology and Radial 

Plume Mapping (ORS-RPM). The first-order equation used to estimate LFG emissions has been 

modified to add a factor to account for LFG capture efficiency. Due to the increase in the use of leachate 

recirculation, a gas production rate to characterize emissions from wet landfills has been added. The rate 

constant is based on an optimum moisture content using data from about 30 landfills using leachate 

recirculation. Information on air emission concerns regarding construction/demolition waste landfills and 

landfill fires have also been added to the AP-42 section. 

iii 
 

 

 

Foreword 

The U.S. Environmental Protection Agency (EPA) is charged by Congress with protecting the 

Nation’s land, air, and water resources. Under a mandate of national environmental laws, the Agency 

strives to formulate and implement actions leading to a compatible balance between human activities 

and the ability of natural systems to support and nurture life. To meet this mandate, EPA’s research 

program is providing data and technical support for solving environmental problems today and 

building a science knowledge base necessary to manage our ecological resources wisely, understand 

how pollutants affect our health, and prevent or reduce environmental risks in the future. 

The National Risk Management Research Laboratory (NRMRL) is the Agency’s center for 

investigation of technological and management approaches for preventing and reducing risks from 

pollution that threaten human health and the environment. The focus of the Laboratory’s research 

program is on methods and their cost-effectiveness for prevention and control of pollution to air, 

land, water, and subsurface resources; protection of water quality in public water systems; 

remediation of contaminated sites, sediments and ground water; prevention and control of indoor air 

pollution; and restoration of ecosystems. NRMRL collaborates with both public and private sector 

partners to foster technologies that reduce the cost of compliance and to anticipate emerging 

problems. NRMRL’s research provides solutions to environmental problems by: developing and 

promoting technologies that protect and improve the environment; advancing scientific and 

engineering information to support regulatory and policy decisions; and providing the technical 

support and information transfer to ensure implementation of environmental regulations and 

strategies at the national, state, and community levels. 

This publication has been produced as part of the Laboratory’s strategic long-term research plan. It is 

published and made available by EPA’s Office of Research and Development to assist the user 

community and to link researchers with their clients. 

Sally C. Gutierrez, Director 

National Risk Management Research Laboratory 

iv 
Acknowledgements 

We would like to thank those providing data and information used to help develop more up-to-date 

and credible emission factors for evaluating air emissions from landfills and combustion by-products 

from the control of landfill gas emissions. We would also like to thank those helping to review this 

report including Jim Topsale of EPA Region III; Tom Driscoll, K.C. Hustvedt, Ron Myers, and 

Hillary Ward of EPA’s Office of Air Quality Planning and Standards; Rachel Goldstein of EPA’s 

Landfill Methane Outreach Program (LMOP); and Bob Wright and Andy Miller of EPA’s Office of 

Research and Development (ORD). 

We would also like to thank the Environmental Research and Education Foundation (EREF). 

Through a Cooperative Research and Development Agreement (#200-C-09) between EPA ORD and 

EREF, co-funding was provided which helped to complete data collection and analysis. Co-funding 

was also received from EPA’s LMOP program to help complete the data analysis to update 

combustion by-products from technologies utilizing methane (i.e., internal combustion engines, 

boilers, and turbines). 

v 
 

 

 

 

TABLE OF CONTENTS
 

Page
 

Notice........................................................................................................................................ii 

Abstract.........................................................................................................................................iii 

Foreword ......................................................................................................................................iv 

Acknowledgements .....................................................................................................................v 

Appendices .................................................................................................................................vii 

List of Tables ............................................................................................................................ viii 

1.0 INTRODUCTION .........................................................................................................................1 

2.0 UNCONTROLLED LANDFILL GAS DATA ANALYSIS RESULTS....................................4 

2.1 Estimation of Uncontrolled Landfill Gas Emissions.............................................4 

2.2 Data Summary ..................................................................................................................10 

2.3 NMOC and VOC ..............................................................................................................14 

2.4 Speciated Organics and Reduced Sulfur Compounds....................................................... 17 

2.5 Methane, Carbon Dioxide, Carbon Monoxide, Oxygen and Nitrogen .............................18 

2.6 Hydrogen Chloride ...........................................................................................................18 

2.7 Landfill Gas Constituent Data for Landfills With Waste in Place Prior to 1992.............. 31 

2.7.1 Data Gathering and Review.................................................................................31 

2.7.2 Development of Default Concentrations .............................................................32 

3.0 CONTROLLED LANDFILL GAS DATA ANALYSIS RESULTS........................................43 

3.1 Flares.................................................................................................................................43 

 3.1.1 Nitrogen Oxides...................................................................................................43 

3.1.2 Carbon Monoxide ................................................................................................44 

3.1.3 Particulate Matter.................................................................................................45 

3.1.4 Total Dioxin/Furan ..............................................................................................45 

3.1.5 Flare Summary.....................................................................................................45 

3.2 Boilers, Engines and Turbines..........................................................................................53 

3.2.1	 Boiler Combustion By-Product Emissions – Source Characterization, Test 

Methods and Results............................................................................................53 

3.2.2	 Internal Combustion (IC) Engine Combustion By-Product Emissions – Source 

Characterization, Test Methods and Results........................................................55 

3.2.3 Gas Turbine Data Summary ................................................................................61 

3.3 Control Device Efficiency Data........................................................................................63 

3.4	 Control Device Carbon Dioxide, Sulfur Dioxide, and Hydrogen Chloride Emissions....64 

4.0 MERCURY EMISSIONS DATA ANALYSIS..........................................................................67 

4.1 Mercury in Raw Landfill Gas ...........................................................................................67 

4.1.1 Total Mercury ......................................................................................................67 

4.1.2 Elemental Mercury ..............................................................................................68 

4.1.3 Monomethyl Mercury..........................................................................................68 

4.1.4 Dimethyl Mercury................................................................................................68 

4.1.5 Mercury Data Summary.......................................................................................68 

4.2 Post-Combustion Mercury Emissions...............................................................................70 

vi 
5.0 AP-42 SECTION 2.4....................................................................................................73(DRAFT) 

Appendix A: Supporting Information for Landfills with Waste in Place Prior to 1992 

Appendix B: List of Emission Test Reports Evaluated in this Update 

Appendix C: Raw Landfill Gas Constituents (Uncorrected for Air Infiltration) 

Appendix D: Background Data for VOC Emission Factor Calculation 

Appendix E: Raw Landfill Gas Data Plots and Statistics 

Appendix F: Control Device Efficiency Data and Analysis 

Appendix G: Example Combustion Product Calculations 

vii 
LIST OF TABLES 

Table Page 

Table 2-1 Recommended Values for k for Use In Modeling Uncontrolled Landfill Gas Emissions........5 

Table 2-2 Comparison of Modeled and Empirical LFG Generation Data.................................................6 

Table 2-3 Impact of Delays in Collecting Gas from Newer Landfill Cells...............................................7 

Table 2-4 Summary of Landfill Gas Emissions Tests.............................................................................10 

Table 2-5 Summary of Test Report Data Contents (Counts of Data Points within Test)........................11 

Table 2-6 Summary of Testing Results for Non-Methane Organic Compounds (NMOC) - 

Corrected and Uncorrected for Air Infiltration .......................................................................14 

Table 2-7 Critieria Used to Determine Recommended Default Emission Factor Ratings ......................17 

Table 2-8 Landfill Gas Constituents........................................................................................................18 

Table 2-9 Summary of Methane, Carbon Monoxide, Carbon Dioxide, Nitrogen, and Oxygen 

Concentrations of Raw Landfill Gas.......................................................................................24 

Table 2-10 Criteria Used to Determine Recommended Default Emission Factor Ratings........................32 

Table 2-11 Default Concentrations for LFG Constituents for Landfills with Waste in Place Prior to 

1992........................................................................................................33 

Table 3-1 Summary of Flare Types and Manufacturers for Landfill Gas Flare Combustion By-Product 

Emissions Test Data ................................................................................................................43 

Table 3-2 Criteria Used to Determine Recommended Default Emission Factor Ratings........................45
 

Table 3-3 Recommended Default Emission Factor Ratings for NOx, CO, PM, and Total Dioxin/Furan 

Landfill Flare Combustion By-Products .................................................................................46
 

Table 3-4 Landfill Gas Flare NOx Emissions Data Used to Develop Combustion By-Product Emission 

Factors.....................................................................................................46 

Table 3-5 Landfill Gas Flare CO Emissions Data Used to Develop Combustion By-Product Emission 

Factors.............. ................................................................................................................... 47 
 

Table 3-6 Landfill Gas Flare PM and Total Dioxin/Furan Emissions Data Used to Develop Combustion 

By-Product Emission Factors..................................................................................................47
 

Table 3-7 Landfill Gas-fired Boiler Emissions Data Used To Develop Combustion By-Product 

Emission Factors .....................................................................................................................55
 

Table 3-8 Landfill Gas-fired IC Engine Emissions Data Used To Develop Combustion By-Product 

Emission Factors .....................................................................................................................57
 

Table 3-9 Landfill Gas-fired Boiler Emissions Data Used To Develop Combustion By-Product 

Emission Factors .....................................................................................................................59
 

Table 3-10 Landfill Gas-fired IC Engine Emissions Data Used To Develop Combustion By-Product 

Emission Factors .....................................................................................................................60
 

Table 3-11 NMOC Control Efficiency Data Analysis Summary ..............................................................63
 

Table 4-1 Raw Landfill Gas Mercury Data Used To Determine AP-42 Default Concentrations ...........69
 

viii 
1.0 INTRODUCTION 

The document "Compilation of Air Pollutant Emission Factors" (AP-42) has been published 

periodically by the U.S. Environmental Protection Agency (EPA) since 1972. New emission source 

categories and updates to existing emission factors to supplement the AP-42 have been routinely 

published. These supplements are in response to the emission factor needs of the EPA, state, and local air 

pollution control programs, and industry. The prior update to this section was performed in 1998 (U.S. 

EPA, 1998). 

This background information document describes the data analysis undertaken to develop 

updated emission factors and guidance for the AP-42 section for Municipal Solid Waste (MSW) 

Landfills. The data being used for this update is from industry-supplied information and additional data 

collected from state and local regulatory agencies. The most comprehensive set of data from 

measurements of five landfills of the header pipe gas and combustion by-products was also used in 

developing updated factors. This data is from a field study by EPA’s Office of Research and 

Development (U.S. EPA, 2007a) which was co-funded by the Environmental Research and Education 

Foundation. 

The data being used to update landfill gas emission factors is primarily from landfills with waste 

in place on or after 1992. Resource Conservation and Recovery Act (RCRA) Subtitle D regulations, 

specifically 40 CFR Part 258, were effective October 9, 1993, but applied to landfills accepting waste on 

or after October 9, 1991. It is, therefore, likely that landfills began instituting the provisions of Subtitle D 

during their operations around 1992. The regulatory provisions limited the types of waste that could be 

landfilled with municipal solid waste (MSW). For example, prior to RCRA Subtitle D, hazardous waste 

could be co-disposed with MSW. Therefore, a distinction is made between the landfill gas (LFG) 

constituents present in data from waste prior to 1992, and those that were measured at landfills with the 

majority of their waste in place on or after 1992. The previous update of AP-42 contained the data for 

LFG with waste in place on or before 1992. This document includes the addition of data for combustion 

by-products from flares, boilers, and engines (control data applies to both pre and post 1992 landfills). 

However, no additional data for gas turbines was received for this update. Therefore, the data present for 

turbines in the last AP-42 update were unchanged during this update. Chapter 2.7 presents the 

background information for the pre-1992 landfills, and supporting information from the previous version 

of the background information document is included as Appendix A for historical purposes. To assist the 

reader in determining where background information is located for a certain type of emission from a 

landfill or control device, the following table is provided to serve as a quick guide on where to go to 

obtain background information on the topics found in the AP-42 section: 

AP-42 Chapter Topic: Location in this Background Information 

Document: 

Calculating Uncontrolled Landfill Gas Emissions Chapter 2.1 

Landfill Gas Constituents From Landfills with 

Waste in Place On or After 1992 

Chapters 2.2 through 2.6 

Landfill Gas Constituents From Landfills with 

Waste in Place Before 1992 

Chapter 2.7 

Control Device Emissions (for both pre and post1992 Landfills) Chapter 3.0 

Mercury Emissions From Landfills with Waste in 

Place on or After 1992 

Chapter 4.0 

2008 Version of AP-42 Chapter 2.4 Municipal 

Solid Waste Landfills 

Chapter 5.0 

1
 
 

In addition to the new data analysis detailed in this background document, there were updates to the AP42 chapter text which are briefly summarized below: 

•	 The introduction to the AP-42 section contains a description of MSW landfills and related landfill 

statistics that were developed prior to the last update in 1998. This information has been updated 

including update updated statistics on U.S. waste disposal. 

•	 Information was added on EPA’s recommended approach for quantifying emissions from area 

sources (OTM 10; http://www.epa.gov/ttn/emc/tmethods.html). This approach uses optical 

remote sensing technology and radial plume mapping (ORS-RPM) to quantify uncontrolled 

emissions from landfills which includes leaks from header pipes, extraction wells, side slopes, 

and landfill cover material. (U.S. EPA, 2007b) Optical remote sensing technologies use an 

optical emission detector such as open-path Fourier transform infrared spectroscopy (FTIR), 

ultraviolet differential absorption spectroscopy (UV-DOAS), or open-path tunable diode laser 

absorption spectroscopy (OP-TDLAS); coupled with radial plume mapping software that 

processes path-integrated emission concentration data and meteorological data to yield an 

estimate of uncontrolled emissions. More information on ORS-RPM is described in the 

Evaluation of Fugitive Emissions Using Ground-Based Optical Remote Sensing Technology 

(EPA/600/R-07/032). Ongoing research is helping to develop additional guidance using OTM 10 

for landfill applications which can be more complex than other area source emissions such as 

waste lagoons and surface impoundments. 

•	 Equation (1) in the AP-42 Section is used to estimate emissions from an uncontrolled landfill. In 

this update, a factor of 1.3 was added to Equation (1) to account for the fact that LO is determined 

by the amount of gas collected by LFG collection systems. The design of these systems will 

typically result in a gas capture efficiency of only 75%. Therefore, 25% of the gas generated by 

the landfill is not captured and included in the development of LO. The ratio of total gas to 

captured gas is a ratio of 100/75 or equivalent to 1.3. An analysis of the efficiency of typical 

LFG collection systems is presented in Appendix E. Previous equation being used did not 

account for total emissions which includes the quantity of gas that is collected plus any fugitive 

loss from leaks that can occur from header pipes, extraction wells, side slopes, and landfill cover 

material. 

•	 There has been an increase in the occurrence of landfills that recirculate leachate to accelerate 

waste decomposition. An additional ‘k’ was added for use in the first-order equation to account 

for the increase in gas production from wet landfills. This was derived from a study that 

evaluated data from 29 wet landfills (Reinhart, 2005). For the purpose of AP-42, wet landfills are 

defined as landfills which add large amounts of liquid to the waste from recycled landfill 

leachate, condensate from LFG collection, and other sources of water such as treated wastewater. 

•	 The use of petroleum contaminated soil or construction and demolition waste as daily cover may 

affect the characteristics of LFG. Primarily, non-methane organic compounds (NMOC) 

concentrations may be much higher in landfills where petroleum contaminated soil is used as 

daily cover. Likewise, sometimes elevated hydrogen sulfide concentrations are observed where 

wall board has been landfilled or recovered gypsum is used as daily cover 

•	 Landfill fires, while uncommon, may occur from time to time. These fires may be significant 

sources of dioxins and other hazardous air pollutants resulting from incomplete combustion of 

material found in MSW. 

2
 
References 

Reinhart, Debra R., Ayman A. Faour, and Huaxin You, First-Order Kinetic Gas Generation 

Model Parameters for Wet Landfills, U. S. Environmental Protection Agency, (EPA-600/R05/072), June 2005 

U.S. Environmental Protection Agency (2007a) Field Test Measurements at Five MSW Landfills 

with Combustion Control Technology for Landfill Gas Emissions, Prepared for EPA’s Office of 

Research and Development (EPA/600/R-07/043, April 2007) - Available at: 

 http://www.epa.gov/ORD/NRMRL/pubs/600r07043/600r07043.pdf 

U.S. Environmental Protection Agency. (2007b) Evaluation of Fugitive Emissions Using GroundBased Optical Remote Sensing Technology (EPA/600/R-07/032, March 07) Available at: 

http://www.epa.gov/nrmrl/pubs/600r07032/600r07032.pdf . 

U.S. Environmental Protection Agency (1998). Compilation of Air Pollutant Emission Factors, 

AP-42, Fifth Edition, Volume I: Stationary Point and Area Sources, Section 2.4 Municipal Solid 

Waste Landfills, Research Triangle Park, NC, November 1998. 

3
 
−kc −kt QCH4 

= Lo R (e − e ) 

 

 

2.0 UNCONTROLLED LANDFILL GAS DATA ANALYSIS RESULTS 

2.1 ESTIMATION OF UNCONTROLLED LANDFILL GAS EMISSIONS 

To estimate uncontrolled emissions of the various compounds present in LFG, total uncontrolled 

LFG emissions must first be estimated. Emissions for uncontrolled LFG depend on several factors 

including: (1) the size, configuration, and operating conditions of the landfill; and (2) the characteristics 

of the refuse such as moisture content, age, and composition. Uncontrolled methane (CH4) emissions 

may be estimated for individual landfills by using a theoretical first-order kinetic model of CH4 

production. This method of estimating emissions could result in conservative estimates of emissions, 

since it provides estimates of LFG generation and not LFG release to the atmosphere. Some capture and 

subsequent microbial degradation of organic LFG constituents within the landfill’s surface layer may 

occur. However, LFG will take the path of least resistance so any leaks in the header pipe, extraction 

wells, side slopes, and cover material will be a potential source of fugitive loss. Although laboratory data 

is available, field test data on potential oxidation or biodegradation through the soil cover for individual 

constituents found in LFG was not available. Therefore the equation being used to estimate LFG 

emissions does not include a factor to account for potential reduction of emissions through soil cover. 

The first-order kinetic model of CH4 production in landfills is based on the following equation 

(U.S. EPA, 1991): 

 (1) 

where: 

QCH4 = Methane generation rate at time t, m3/yr;

 LO = Methane generation potential, m3 CH4/Mg refuse; 

R = Average annual refuse acceptance rate during active life, Mg/yr; 

e = Base log, unitless; 

k = Methane generation rate constant, yr-1; 

c = Time since landfill closure, yrs (c = 0 for active landfills); and 

t = Time since the initial refuse placement, yrs. 

Site-specific landfill information is generally available for variables R, c, and t. When refuse 

acceptance rate information is scant or unknown, R can be estimated by dividing the refuse in place by 

the age of the landfill (U.S. EPA, 1991). If a facility has documentation that a certain segment (cell) of a 

landfill has received only nondegradable refuse, then the waste from this segment of the landfill can be 

excluded from the calculation of R. Nondegradable refuse includes, but is not limited to, concrete, brick, 

stone, glass, plaster, piping, plastics, and metal objects. The average annual acceptance rate should only 

be estimated by this method when there is inadequate information available on the actual annual 

acceptance rate. 

Values for the variables LO and k must be estimated. The potential CH4 generation capacity of 

refuse (LO) is dependent on the organic (primarily cellulose) content of the refuse and can vary widely 

[6.2 to 270 m3

 CH4/Mg refuse (200 to 8670 ft3/ton)] (U.S. EPA, 1991). The value of the CH4 generation 

constant (k) is dependent on moisture, pH, temperature, and other environmental factors, as well as 

landfill operating conditions (U.S. EPA, 1991). 

A computer program that uses the theoretical model discussed above was developed by EPA and 

is known as Landfill Gas Emission Model or LandGEM (U.S. EPA, 2005). This model and User’s Guide 

can be accessed from the Office of Air Quality Planning and Standards Technology Transfer Network 

4
 
 

Website (OAQPS TTN Web) in the Clearinghouse for Inventories and Emission Factors (CHIEF) 

technical area (URL http://www.epa.gov/ttncatc1/products.html#software). 

LandGEM includes both regulatory default values and recommended AP-42 default values for LO 

and k (see below). The regulatory defaults, called “CAA factors,” were developed for regulatory 

compliance purposes [New Source Performance Standards (NSPS), National Emissions Standards for 

Hazardous Air Pollutants (NESHAP) and Emission Guidelines (EG)] and provide conservative default 

values for municipal landfills. As a result, the regulatory LO and k default values may not be 

representative of specific landfills, and may not be appropriate for use in an emissions inventory. 

Therefore, the LandGEM also includes a set of factors called “inventory factors” that are recommended 

for use when estimating LFG emissions for inventory purposes. LandGEM computes the total CH4 

generation based on the age of each landfill segment. 

The recommended AP-42 defaults for k when estimating CH4 emissions for inventory purposes 

are presented in Table 2-1. These recommendations are based on a comparison of gas-yield forecasts 

with LFG recovery data (U.S. EPA, 1991). 

TABLE 2-1. RECOMMENDED VALUES OF k FOR USE IN MODELING UNCONTROLLED 

LANDFILL GAS EMISSIONS 

Landfill Conditions Inventory k Value 

Areas receiving <25 inches/yr rainfall (U.S. EPA, 1991) 0.02 

Areas receiving >25 inches/yr rainfall (U.S. EPA, 1991) 0.04 

Wet landfills (Reinhart, 2005) 0.3 

Based on work conducted in the late 1980’s and early 1990’s, a default LO value of 100 m3

/Mg 

(3,530 ft3

/ton) refuse has been recommended for emission inventory purposes (Pelt, 1993). This LO value 

was recommended because it provided the best agreement between emissions derived from empirical 

(measured) data to predicted emissions. The results of this comparison are depicted in Table 2-2. It must 

be emphasized that when complying with the NSPS and Emission Guideline, the regulatory defaults for k 

and Lo must be applied. 

As part of this update of landfill emission factors, additional guidance is provided for estimating 

the flow rate of LFG from both controlled and uncontrolled landfills. The LO value mentioned above of 

100 m3

/Mg was based on data obtained by EPA from tests at 40 landfills conducted in the late 1980’s and 

early 1990’s (U.S. EPA, 1991). When the data from these landfills was used to develop the constants for 

the first order decay equation, the amount of gas that is uncontrolled was not accounted for in the 

equation. To correct for this, a factor has been added to estimate total emissions (both collected and 

uncontrolled). 

The overall collection efficiency of a LFG collection system is affected by two factors: the 

specific collection efficiency of the gas collection system, and the portion and age of the waste that is 

excluded from the collection system. Specific collection efficiencies can range greatly based on the 

design of the landfill design and how well it is maintained and operated. A highly efficient collection 

system will include a liner under the waste and a cover over the waste that is comprised of a 

geomembrane and a thick layer of low-porosity clay. Each gas well in the high efficiency system is 

typically sealed to the geomembrane with a thick plug of bentonite clay material. Each gas well in the 

system is maintained under a strong vacuum and is monitored monthly. The landfill surface is also 

monitored frequently to identify leaks and initiate repairs immediately. Collection efficiencies as high as 

95% have been reported for well designed and maintained LFG collection systems. However, the 

5
 
 

 

 

 

 

collection efficiencies for a landfill that is unlined, has only a soil or porous clay cap and does not employ 

an aggressive operation and maintenance program might easily be as low as 50% to 60%. 

TABLE 2-2. COMPARISON OF MODELED AND EMPIRICAL LFG GENERATION DATA 

WHEN LO IS SET AT 100 m3

/Mga
 

Predicted CH4 Predicted/ Predicted CH4 Predicted/ 

Landfillb (106 m3/yr) Empirical CH4 Landfillb (106 m3/yr) Empirical CH4 

a 37.6 0.68 u 4.62 0.63 

b 39.9 0.77 v 10.5 1.44 

c 31.8 0.73 w 4.28 0.72 

d 49.8 1.51 x 5.62 0.96 

e 12.1 0.53 y 2.39 0.44 

f 17.3 0.82 z 9.59 1.84 

g 23.6 1.28 aa 5.08 1.08 

h 8.61 0.49 bb 4.93 1.15 

i 14.9 0.93 cc 3.93 0.93 

j 14.5 0.94 dd 2.74 1.03 

k 14.2 0.96 ee 8.37 3.23 

l 7.16 0.50 ff 117 0.83 

m 18.0 1.31 gg 14.4 0.58 

n 8.57 0.76 hh 23.0 1.44 

o 4.56 0.48 ii 29.6 2.19 

p 17.4 1.87 jj 19.3 1.47 

q 10.2 1.21 kk 22.4 1.71 

r 6.95 0.87 ll 41.3 4.00 

s 2.29 0.29 mm 7.14 0.81 

t 3.49 0.45 nn 1.07 0.29 

 Average 1.10 

 Maximum 3.23 

 Minimum 0.29 

 Standard Dev. 0.73 

a

 k = 0.04
 b

 Landfill names are considered to be confidential. 

The second factor which has a very significant influence on collection efficiency is the portion 

and age of the waste that is excluded from the gas collection system. There is normally a lag time 

between the placement of waste in a new landfill cell and the installation of a gas collection system in the 

cell. Landfills that have reached a sufficient size (i.e., waste in place is equal or greater than 2.5 million 

tons of waste) and NMOC emissions equal or exceed 50 megagrams per year are required by NSPS and 

EG to install a gas collection system. The time table specified in the NSPS/EG is that gas collection is to 

6
 
 

be installed in open cells within five years of initial waste placement and in cells that have been closed for 

two or more years. As a result, a typical landfill will not have the most recent two to five years of waste 

included within its gas collection system. The impact of excluding the most recent portions of their waste 

mass from the collection system is magnified by the fact that the LFG emission rate is greatest in the first 

years of the waste’s life and drops rapidly with time. 

Therefore, a system capable of collecting 90% of the gas generated from the landfill cells in 

which it is installed is operating at reduced landfill-wide collection efficiency (i.e., less than 90%) due to 

the loss of uncollected gas from cells that have yet to be capped and connected to the collection system. 

All active landfills contain open cells and waste cells that have yet to be capped and fitted with a gas 

collection system. Table 2-3 demonstrates the impact of the delay in collecting gas from newer cells. 

The values in this table were generated using the first order decay model (Pelt, 1993) and assuming a LO 

of 100 and a k of 0.04. The landfill was assumed to be operating (i.e., accepting waste) over a 20 year 

timeframe. 

The years of delay between the placement of waste in a cell and the installation of wells in the 

cell are presented in the first column of Table 2-3. The effective landfill-wide collection efficiency of the 

gas collection system is presented in the second and third columns for gas collection systems with 

efficiencies of 90% and 85%, respectively. Large active landfills will typically install gas collection 

systems within two to five years after waste placement in a given cell, as required by the NSPS. As 

shown in Table 2-3, the effective landfill-wide collection efficiency of a gas collection system which is 

installed in waste cells two to five years after they are filled varies from 57% to 77% for systems with 

85% to 90% efficiency. If a landfill is closed, all cells will be capped and the landfill-wide collection 

efficiency will be the same as the specific efficiency of the collection system, or 85% to 90%. 

TABLE 2-3. IMPACT OF DELAYS IN COLLECTING GAS 

FROM NEWER LANDFILL CELLS 

Time Between 

Waste Placement 

and Initial Gas 

Collection for 

Individual Cells 

(years) 

Effective Landfillwide Gas Collection 

Efficiency 

System 

Collection 

Efficiency 

90% 

System 

Collection 

Efficiency 

85% 

1 84 79 

2 77 73 

3 72 68 

4 66 62 

5 60 57 

6 55 52 

It is assumed that the landfills used to develop LO and k for use in the first order decay LFG 

generation equation included a similar number of both open and closed landfills. Typically these landfills 

in the late 1980’s and early 1990’s would have had specific collection efficiencies of 85% to 90% for the 

closed cells where the system was installed. The closed landfills might have an overall efficiency of 

85%-90% and the open landfills might have an efficiency ranging from 57% to 77%. Based on these 

assumptions, the overall set of landfills used to develop LO and k would have had overall collection 

efficiencies ranging from 57% to 90% and possibly averaging 75%. 

7
 
 

 

 

 

 

 

Using the analysis presented on the range in gas collection efficiency, a factor is added to account 

for the gas that is not collected given that empirical data was used to develop input for the first-order 

decomposition rate equation. If on average 75% gas generated at the landfills listed in Table 2-2 is 

collected, then actual gas production from landfills would then be 100/75 or 1.3 times greater than the 

gas flow measured in the gas collection systems. The first order decay model developed by the EPA 

(Pelt, 1993) would then be expressed as: 

−kc −kt QCH4 

=1.3Lo R (e − e ) (2) 

where: 

QCH4 = Methane generation rate at time t, m3/yr; 

Lo = Methane generation potential, m3

 CH4/Mg of “wet” or “as received” refuse; 

R = Average annual refuse acceptance rate during active life, Mg of “wet” or “as received” 

refuse /yr; 

e = Base log, unitless; 

k = Methane generation rate constant, yr-1; 

c = Time since landfill closure, yrs (c = 0 for active landfills); and 

t = Time since the initial refuse placement, yrs. 

When annual refuse acceptance data is available, the following form of Equation (2) is used. This 

is the equation that is used in EPA’s Landfill Gas Emissions Model (LandGEM). Due to the complexity 

of the double summation, Equation (2 alt) is normally implemented within a computer model. Equation 

(2 alt.) is more accurate because it accounts for the varying annual refuse flows and it calculates each 

year’s gas flow in 1

/10th year increments. 

n 1 Ri −ktij QCH4 = 1.3∑ ∑ k Lo e (2 alternate) 10

i=1 j=0.1

where: 

= Methane generation rate at time t, m3 Q /yr; CH4 

Lo = Methane generation potential, m3

 CH4/Mg of “wet” or “as received” refuse; 

Ri = Annual refuse acceptance rate for year i, Mg of “wet” or “as received” refuse /yr; 

e = Base log, unitless; 

k = Methane generation rate constant, yr-1; 

c = Time since landfill closure, yrs (c = 0 for active landfills); and 

t = Time since the initial refuse placement, yrs. 

i = year in life of the landfill 

j = 1

/10th year increment in the calculation. 

Equations (2) and (2 alt) are different from the equations used previously by EPA in AP-42 and in other 

models such as LandGEM, by the addition of the constant 1.3 at the front of the equation. This 1.3 

constant compensates the value of LO that had been developed based on systems nominally collecting 

only an estimated 75% of the LFG emissions. 

There is a significant level of uncertainty in Equation 2 and its recommended defaults values for k 

and Lo. The recommended defaults k and Lo for conventional landfills, based upon the best fit to 40 

different landfills, yielded predicted CH4 emissions that ranged from ~30 to 400% of measured values and 

8
 
had a relative standard deviation of 0.73 (Table 2-2). The default values for wet landfills were based on a 

more limited set of data and are expected to contain even greater uncertainty. 

When gas generation reaches steady-state conditions, sampled LFG consists of approximately 

equal amounts of carbon dioxide (CO2) and CH4; and only trace amounts of NMOC (typically, less than 

two percent). Therefore, the estimate derived for CH4 generation using the landfill model can also be used 

to estimate CO2 generation (i.e., CO2 = CH4) (U.S. EPA, 1991). In addition, total LFG flow can be 

assumed to be equal to twice the CH4 flow. 

References 

Pelt, R., Memorandum "Methodology Used to Revise the Model Inputs in the Solid Waste 

Landfills Input Data Bases (Revised)", to the Municipal Solid Waste Landfills Docket No. A-88­

09, April 28, 1993. 

Reinhart, Debra R., Ayman A. Faour, and Huaxin You, First-Order Kinetic Gas Generation 

Model Parameters for Wet Landfills, U. S. Environmental Protection Agency, (EPA-600/R05/072), June 2005. 

U.S. Environmental Protection Agency. Air Emissions from Municipal Solid Waste Landfills - 

Background Information for Proposed Standards and Guidelines, EPA-450/3-90-011a, 

Office of Air Quality Planning and Standards, Research Triangle Park, NC, March 1991. 

U.S. Environmental Protection Agency (2005) Landfill Gas Emission Model (LandGEM) - 

Software and Manual, EPA-600/R-05/047, May 2005. Available at: 

http://www.epa.gov/ORD/NRMRL/pubs/600r05047/600r05047.htm 

9
 
 

 

 

 

 

2.2 DATA SUMMARY 

A total of 293 emission tests were submitted to EPA that included LFG composition data. As 

listed in Table 2-4, a portion of these were not used because either the report did not present actual test 

data (they were based on emission models) or the test report was too incomplete to evaluate the quality of 

the data. Of the potentially useful tests, several (22) analyze LFG obtained through use of a “punchprobe,” while 62 tests contain data for gas samples from LFG collection system headers. The emissions 

data from the collection system headers are assumed to be representative of the gas generated by the 

entire landfill and not selected locations, as may be the case with punch probe analyses. Therefore, in 

developing default emission factors for updating AP-42, only the emissions test data for the 62 tests taken 

from gas collection system headers are analyzed in this report. 

The reference section to this chapter, and in the AP-42 chapter, lists the specific emission tests 

from which data were utilized. Appendix B contains the list of all 293 emission tests that were reviewed 

as part of this update. 

TABLE 2-4. SUMMARY OF LANDFILL GAS EMISSIONS TESTS 

Number of emission test reports 293 

Number of reports that were not able to be used due to 

inadequate documentation or information 

209 

Number of punch-probe tests 22 

Number of gas collection header tests 62 

Landfill gas collection system header pipes were sampled for NMOC, reduced sulfur compounds, 

and speciated organics. Measured pollutant concentrations (i.e., as measured by EPA Reference Method 

25C), must be corrected for air infiltration which can occur by two different mechanisms: LFG sample 

dilution and air intrusion into the landfill. These corrections require site-specific data for the LFG CH4, 

CO2, nitrogen (N2), and oxygen (O2) content. If the ratio of N2 to O2 is less than or equal to 4.0 (as found 

in ambient air), then the total pollutant concentration is adjusted for sample dilution by assuming that CO2 

and CH2 are the primary (100 percent) constituents of LFG, and the following equation is used: 

C x (1x106) CP (corrected for air infiltration) = P (3) C CO2 + CCH4 

where: 

CP = Concentration of pollutant P in LFG (i.e., NMOC as hexane), ppmv; 

C = CO2 concentration in LFG, ppmv; CO2

Q = CH4 Concentration in LFG, ppmv; and CH4 

1 x 106 = Constant used to correct concentration of P to units of ppmv. 

If the ratio of N2 to O2 concentrations (i.e., CN2, CO2) is greater than 4.0, then the total pollutant 

concentration should be adjusted for air intrusion into the landfill by using Equation (3) and adding the 

concentration of N2 (i.e., CN2) to the denominator. Values for CCO2, CCH4, CN2, CO2, can usually be found 

in the source test report for the particular landfill along with the total pollutant concentration data. 

Most of the tests contained data on O2, CO2, CH4 and N2 content of the gas, as shown in Table 2­

5, so that corrected values may be calculated. (While no reports present corrected data, Table 2-5 contains 

those tests for which corrected values could be calculated.) Table 2-6 displays NMOC values both 

10
 
 

uncorrected (i.e., as reported) and corrected for air infiltration. For simplicity, the AP-42 chapter and 

Table 2-7 of this section present the data that has been corrected for air infiltration only. A summary of 

uncorrected data is presented in Appendix C. 

TABLE 2-5. SUMMARY OF TEST REPORT DATA CONTENTS 

(COUNTS OF DATA POINTS WITHIN TEST) 

Test Report 

ID CH4 CO2 N2 O2 

CO NMOC 

(as hexane) 

Speciated 

Organic and 

Sulfur 

Compounds 

Total 

C UC C UC C UC C UCa 

TR-076 0 0 1 1 0 0 0 1 0 0 0 3 

TR-084 0 0 1 1 0 0 0 1 0 0 0 3 

TR-086 0 0 1 1 0 0 0 1 0 0 0 3 

TR-114 0 0 1 0 0 0 0 1 0 0 0 2 

TR-115 0 0 0 0 0 0 0 1 0 0 0 1 

TR-134 0 0 1 1 0 0 0 1 0 0 0 3 

TR-141 0 0 1 1 0 0 0 1 0 0 0 3 

TR-145 1 1 1 1 1 1 1 1 28 28 30 34 

TR-146 1 1 1 1 0 0 1 1 3 3 4 8 

TR-147 0 0 0 0 0 1 0 1 0 1 0 3 

TR-148 1 1 1 1 1 1 1 1 15 15 17 21 

TR-153 1 1 1 1 0 0 1 1 0 0 1 5 

TR-156 1 1 1 1 0 0 1 1 0 0 1 5 

TR-157 1 1 1 1 0 0 1 1 0 0 1 5 

TR-159 1 1 1 1 0 0 1 1 0 0 1 5 

TR-160 0 0 0 0 0 0 0 1 0 0 0 1 

TR-165 1 1 1 1 0 0 1 1 27 27 28 32 

TR-167 1 1 1 1 0 0 1 1 27 27 28 32 

TR-168 1 1 1 1 0 0 1 1 27 27 28 32 

TR-169 1 1 1 1 0 0 1 1 27 27 28 32 

TR-171 1 1 1 1 0 0 1 1 27 27 28 32 

TR-173 1 1 1 1 0 0 1 1 27 27 28 32 

TR-175 1 1 1 1 1 1 1 1 27 27 29 33 

TR-176 1 1 1 1 0 0 1 1 21 21 22 26 

TR-178 1 1 1 1 0 0 1 1 27 27 28 32 

TR-179 1 1 0 1 0 0 0 1 0 27 0 31 

TR-181 1 1 1 1 0 0 1 1 27 27 28 32 

11
 
 

TABLE 2-5 (CONTINUED). SUMMARY OF TEST REPORT DATA CONTENTS 

(COUNTS OF DATA POINTS WITHIN TEST) 

Test Report 

ID CH4 CO2 N2 O2 

CO NMOC 

(as hexane) 

Speciated 

Organic and 

Sulfur 

Compounds 

Total 

C UC C UC C UC C UCa 

TR-182 1 1 1 1 0 0 1 1 27 27 28 32 

TR-183 1 1 1 1 0 0 1 1 27 27 28 32 

TR-187 1 1 1 1 0 0 1 1 47 47 48 52 

TR-188 1 1 1 1 1 1 0 0 108 108 109 113 

TR-189 1 1 1 1 1 1 0 0 113 113 114 118 

TR-190 1 1 1 1 0 0 0 0 107 107 107 111 

TR-191 1 1 1 1 0 0 0 0 107 107 107 111 

TR-194 1 1 0 1 0 1 0 0 0 98 0 102 

TR-195 0 0 0 0 0 0 0 0 0 526 0 526 

TR-196 1 1 1 1 0 0 1 1 27 27 28 32 

TR-199 1 1 1 1 0 0 1 1 23 23 24 28 

TR-205 1 1 1 1 0 0 1 1 27 27 28 32 

TR-207 1 1 1 1 0 0 1 1 25 25 26 30 

TR-209 1 1 1 1 0 1 1 1 28 28 29 34 

TR-220 1 1 1 1 0 0 1 1 22 22 23 27 

TR-226 1 1 1 1 1 1 1 1 0 0 2 6 

TR-229 1 1 1 1 0 0 1 1 30 30 31 35 

TR-236 0 0 0 0 0 0 0 0 0 7 0 7 

TR-241 1 1 1 1 0 0 0 0 5 5 5 9 

TR-251 1 1 1 1 0 0 1 1 27 27 28 32 

TR-253 1 1 1 1 0 0 1 1 27 27 28 32 

TR-255 1 1 1 1 0 0 1 1 27 27 28 32 

TR-258 0 0 0 0 0 0 0 1 0 0 0 1 

TR-259 1 1 1 1 0 0 1 1 27 27 28 32 

TR-260 1 1 1 1 0 0 1 1 26 26 27 31 

TR-261 1 1 1 1 0 0 1 1 27 27 28 32 

TR-264 1 1 1 1 0 0 1 1 27 27 28 32 

TR-266 1 1 0 1 0 1 1 1 9 9 10 14 

TR-272 2 2 1 1 0 0 1 1 68 68 69 75 

TR-273 2 2 1 1 0 0 1 1 67 67 68 74 

TR-284 2 2 1 1 0 0 1 1 56 56 57 63 

TR-287 2 2 1 1 0 0 1 1 56 56 57 63 

TR-290 1 1 1 1 0 0 1 1 27 27 28 32 

12
 
 

TABLE 2-5 (CONTINUED). SUMMARY OF TEST REPORT DATA CONTENTS 

(COUNTS OF DATA POINTS WITHIN TEST) 

Test Report 

ID CH4 CO2 N2 O2 

CO NMOC 

(as hexane) 

Speciated 

Organic and 

Sulfur 

Compounds 

Total 

C UC C UC C UC C UCa 

TR-292 2 2 1 1 0 0 1 1 33 33 34 40 

TR-293a 1 1 1 1 0 0 1 1 30 30 31 35 

TR-293b 1 1 1 1 0 0 1 1 26 26 27 31 

Total 56 54 52 54 6 10 44 55 1,537 2,196 1,585 2,473 

C = Corrected for air infiltration 

UC = Uncorrected 

a

 Uncorrected Total includes CH4, CO2, N2, and O2 data points. 

13
 
 

 

 

2.3 NMOC AND VOC 

Fifty-four test reports contained NMOC data. Forty-three of these contained sufficient data to 

calculate a value corrected for air infiltration. The corrected values were calculated using Equation 2. 

The data from the 54 test reports, corrected value (if possible to calculate), and the test method are 

reported in Table 2-6. In addition, summary statistics are presented at the bottom of the table. Based on 

guidance contained in EPA’s Procedures for Preparing Emission Factor Documents (U.S. EPA, 1997a), 

each of the tests with the corrected value calculated are assumed to be rated as “A,” because the tests were 

performed by a sound methodology and reported in enough detail for adequate validation. None of the 

NMOC concentrations were below the detection limit (BDL). 

Taking the mean value of the corrected NMOC data yields a default emission factor of 838 ppmv, 

which compares to the pre-1992 AP-42 default value of 595 ppmv for “No or Unknown co-disposal 

landfills” (see Table 2.4-2 in the AP-42 chapter, included as section 5.0 of this document). An overall 

emission factor ranking of “A” is recommended for NMOC. This rating exemplifies the fact that the 

default NMOC emission factors were developed using A-rated test data from a large number of facilities. 

The pre-1992 AP-42 default emission factor for NMOC at “No or Unknown co-disposal” landfills is 

ranked as “B.” 

To determine the volatile organic compound (VOC) emission factor, the compounds listed in 40 

CFR 51.100(s)(1) which have negligible chemical photoreactivity were removed from the overall NMOC 

concentration. This determination was possible for 34 emission tests that contained both speciated data 

and NMOC data. Consistent with the previous AP-42 update background document (U.S. EPA, 1997b), 

the following compounds from 40 CFR 51.100(s)(1) were removed from the NMOC concentration to 

obtain a VOC fraction: ethane, chlorodifluoromethane, acetone, dichloromethane, 1,1,1-Trichloroethane 

(methyl chloroform), dichlorodifluoromethane, perchloroethylene. Note that 40 CFR 51.100(s)(1) 

contains more compounds than those listed above, but this list envelops the LFG constituents that are 

listed in 51.100(s)(1) that are most prevalent in LFG. Since NMOC is presented as hexane (i.e., six 

carbons), the non-VOC compound concentrations are converted to be on the same six-carbon basis also so 

that they may be subtracted from the NMOC concentration value. The data used to develop the VOC 

emission factor and the resulting VOC fraction calculations are presented in Appendix D. 

The resulting fraction of NMOC that is VOC is 0.997, based on data from 34 emission test 

reports (see Appendix D for data and calculation). All of these test reports are considered to be “A” 

quality. This fraction was multiplied by the corrected NMOC concentration value to obtain a VOC 

emission factor of 835 ppmv. The recommended emission factor ranking is “A” because a large number 

of “A” quality tests were used to develop the emission factor. Appendix E presents statistical data graphs 

of the NMOC data. 

TABLE 2-6. SUMMARY OF TESTING RESULTS FOR NON-METHANE ORGANIC 

COMPOUNDS (NMOC) – CORRECTED AND UNCORRECTED FOR AIR INFILTRATION 

Test 

Report 

ID 

Test Method 

Corrected Average 

Concentration 

(ppm as hexane) 

Average 

Concentration 

(ppm as hexane) 

TR-076 EPA Method 25C 157 

TR-084 EPA Method 25C / Method 3C 117 

TR-086 EPA Method 25C / Method 3C 121 

14
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

TABLE 2-6 (CONTINUED). SUMMARY OF TESTING RESULTS FOR NON-METHANE 

ORGANIC COMPOUNDS (NMOC) – CORRECTED AND UNCORRECTED FOR AIR 

INFILTRATION
 

Test 

Report 

ID 

Test Method 

Corrected Average 

Concentration 

(ppm as hexane) 

Average 

Concentration 

(ppm as hexane) 

TR-114 EPA Method 25C 53 

TR-115 EPA Method 25C 82 

TR-134 EPA Method 25C 944 

TR-141 EPA Method 25C 180 

TR-145 EPA Method 25C 635 628 

TR-146 SCAQMD Method 25.2 927 922 

TR-147 EPA Method 25C 298 

TR-148 EPA Method 18 / EPA Method 25C 332 331 

TR-153 EPA Method 25C 721 726 

TR-156 EPA Method 25C 575 573 

TR-157 EPA Method 25C 574 571 

TR-159 NJATM 3.9 31 31 

TR-160 EPA Method 18 421 

TR-165 SCAQMD Method 25.2 713 698 

TR-167 SCAQMD Draft Method 25.2 673 665 

TR-168 SCAQMD Method 25.2 1,314 1,294 

TR-169 SCAQMD Draft Method 25.2 1,389 1,349 

TR-171 SCAQMD Draft Method 25.2 1,021 993 

TR-173 SCAQMD Method 25.1 1,425 1,400 

TR-175 SCAQMD Method 25.1 161 110 

TR-176 SCAQMD Draft Method 25.2 623 577 

TR-178 SCAQMD Method 25.1 1,947 1,882 

TR-179 SCAQMD Method 25.1 1,244 

TR-181 SCAQMD Draft Method 25.2 649 627 

TR-182 SCAQMD Draft Method 25.2 596 578 

TR-183 SCAQMD Method 25.1 734 717 

TR-187 SCAQMD Method 25.2 870 847 

TR-196 EPA Method 25 Modified 889 883 

TR-199 SCAQMD Method 25.1 193 176 

TR-205 SCAQMD Draft Method 25.2 647 627 

TR-207 SCAQMD Method 25.1 617 560 

TR-209 EPA Method TO-12 Modified 536 529 

TR-220 SCAQMD Draft Method 25.2 704 668 

TR-226 NJDEP Method 3.9 (Modified) / GC 167 145 

TR-229 SCAQMD Draft Method 25.2 564 527 

TR-251 SCAQMD Method 25.1 1,067 1,031 

TR-253 SCAQMD Draft Method 25.2 583 573 

TR-255 SCAQMD Method 25.1 1,122 1,104 

TR-258 EPA Method TO-12 137 

TR-259 SCAQMD Draft Method 25.2 1,349 1,286 

TR-260 SCAQMD Draft Method 25.2 1,349 1,294 

TR-261 SCAQMD Draft Method 25.2 1,321 1,279 

15
 
 

 

 

 

 

 

 

 

 

 

 

 

 

TABLE 2-6 (CONTINUED). SUMMARY OF TESTING RESULTS FOR NON-METHANE 

ORGANIC COMPOUNDS (NMOC) – CORRECTED AND UNCORRECTED FOR AIR 

INFILTRATION
 

Test 

Report 

ID 

Test Method 

Corrected Average 

Concentration 

(ppm as hexane) 

Average 

Concentration 

(ppm as hexane) 

TR-264 SCAQMD Method 25.1 537 523 

TR-266 

SCAQMD Method 100.1 and EPA Methods 

6C and 7E 245 151 

TR-272 EPA Method 25C 386 374 

TR-273 EPA Method 25C 526 355 

TR-284 EPA Method 25C 5,387a

 5,870a 

TR-287 EPA Method 25C 868 1,006 

TR-290 Fuel Gas Analysis (SCAQMD Draft 25.2) 972 954 

TR-292 EPA Method 25C 242 233 

TR-293a EPA Method 25C 378 446 

TR-293b EPA Method 25C 297 317 

Number of Test Reports 44 55 

Minimum 31 31 

Maximum 5,387 5,870 

Mean 838 731 

Standard Deviation 811 824 

95% Confidence Interval ± 240 ± 218 a

 The TR-284 landfill utilized petroleum-contaminated soil as daily cover, which helps illustrate the 

potential for increased emissions of NMOC when this daily cover is used at a landfill. 

To estimate uncontrolled emissions of NMOC or other LFG constituents, such as those listed in 

Table 2-7, the following equation should be used: 

Q CH4 x CP Q = (4) P CCH x (1x106

) 4 

where: 

QP = Emission rate of pollutant P (i.e., NMOC), m3

/yr; 

QCH4

 = CH4 generation rate, m3/yr (from Equation 1); 

CP	 = Concentration of pollutant P in LFG, ppmv; and 

C = Concentration of CH4 in the LFG (assumed to be 50% expressed as 0.5) CH4 

Uncontrolled mass emissions per year of total NMOC (as hexane) and speciated organic and 

inorganic compounds can be estimated by the following equation: 

MWP x1 atm UM P = QP x	 (5) −5 3 o (8.205x10 m − atm/gmol − K) x (1000g/kg) x (273+ T)

where: 

UMP = Uncontrolled mass emissions of pollutant P (i.e., NMOC), kg/yr; 

MWP = Molecular weight of P, g/gmol (i.e., 86.18 for NMOC as hexane); 

QP = Emission rate of pollutant P, m3

/yr; and 

16
 
 

T = Temperature of LFG, oC. 

This equation assumes that the operating pressure of the system is approximately 1 atmosphere. 

If the temperature of the LFG is not known, a temperature of 25 o

C (77 oF) is recommended. 

2.4 SPECIATED ORGANICS AND REDUCED SULFUR COMPOUNDS 

Forty-seven test reports contained speciated organic and reduced sulfur compound data that could 

be corrected for air infiltration. An additional 20 test reports contained data that were not able to be 

corrected. For the speciated organic data, EPA Method 25C was used to obtain the majority of the data. 

Other methods used to determine speciated organic concentrations were EPA Methods TO-14 and TO-15, 

and South Coast Air Quality Management District’s (SCAQMD) Method 25.2. For reduced sulfur 

measurements, EPA Method 18 and SCAQMD Method 307 were used. 

EPA’s Procedures for Preparing Emission Factor Documents (U.S. EPA, 1997a), were followed 

when addressing BDL test runs. In most cases, there were some runs that were below detection limit and 

others that were above. However, for a few compounds, there were no tests (or individual runs) that 

measured above the detection limit. Per the EPA’s guidance (U.S. EPA, 1997a), in these cases the 

emission factor recorded is “BDL,” with a reference to the range of method detection limits (MDL) 

reported. 

Table 2-8 presents the default emission factor information for the speciated organic compounds 

and reduced sulfur compounds that were corrected for air infiltration. As discussed earlier, these data will 

be presented in the AP-42 chapter. Therefore, only these data have recommended emission factor ratings. 

Since all of these tests are considered “A” quality, then the emission factor ranking becomes more of a 

function of the number of data points used for that compound. The following criteria, used in developing 

ratings in the 1997 AP-42 update (U.S. EPA, 1997b), were used to provide recommended default 

emission factor ratings. Statistical data graphs of several of the more prevalent speciated organic 

compounds and reduced sulfur compounds are presented in Appendix E. 

TABLE 2-7. CRITERIA USED TO DETERMINE RECOMMENDED DEFAULT EMISSION 

FACTOR RATINGS 

Factor Rating # of Data Points 

A ≥ 20 

B 10-19 

C 6-9 

D 3-5 

E <3 

Default emission factors for two compounds presented in Table 2-8 could not be calculated since 

the test values were all reported as BDL in the respective test reports. The data for acrylonitrile consisted 

of six BDL test values, and there was one BDL test value reported for hexachlorobutadiene. The 

acrylonitrile BDL data is consistent with information received from California Air Resources Board 

regarding testing for acrylonitrile at a San Diego landfill. 

Appendix C presents the data summary for data that is not corrected for air infiltration. While 

this uncorrected data will not be presented in AP-42, it is shown here to document that it is available and 

was extracted from the test reports. If, in the future, some methodology for assuming a correction factor 

17
 
 

 

 

is available or more information from specific tests is received, then these data may be corrected and 

incorporated into the final default emission factors. 

2.5 METHANE, CARBON DIOXIDE, CARBON MONOXIDE, OXYGEN AND NITROGEN 

Table 2-9 presents a summary of the CH4, CO2, carbon monoxide (CO), O2 and N2 data. AP-42 

presents CO data, but not the other compounds. However, as discussed above, CH4, CO2, O2 and N2 are 

used to correct for air infiltration, per Equation 3. CO measurements were performed using various 

methods, including EPA Method 10, Modified Method TO-14. Ten emission tests contained data for CO 

(TR-145, TR-147, TR-148, TR-175, TR-188, TR-189, TR-194, TR-209, TR-226, TR-241, and TR-266) 

and six of these data points were correctable for air infiltration. The average of the emissions tests results 

in a CO default emission factor of 21 ppmv (corrected for air infilteration). Since there are only six data 

points, the recommended emission factor rating for CO is C. 

2.6 HYDROGEN CHLORIDE 

One test report (TR-147) contained data for hydrogen chloride (HCl) present in the raw LFG. 

However, due to the lack of data for CH4, CO2, N2, and O2 the HCl data point could not be corrected for 

air infiltration. 

TABLE 2-8. LANDFILL GAS CONSTITUENTS 

Compound 

Number 

of Test 

Reports 

Minimum 

(ppm) 

Maximum 

(ppm) 

Mean 

(ppm) 

Standard 

Deviation 

(ppm) 

95% 

Confidence 

Interval 

(± ppm) 

Recommended 

Emission 

Factor Rating 

1,1,1-Trichloroethane 33 5.15E-03 8.50E-01 2.43E-01 2.43E-01 8.30E-02 A 

1,1,2,2-Tetrachloroethane 2 3.06E-02 1.04E+00 5.35E-01 7.14E-01 9.89E-01 E 

1,1,2,3,4,4-Hexachloro-1,3­

butadiene 

(Hexachlorobutadiene) 

3 1.03E-03 7.91E-03 3.49E-03 3.83E-03 4.33E-03 D 

1,1,2-Trichloro-1,2,2­

Trifluoroethane (Freon 113) 9 2.06E-03 4.60E-01 6.72E-02 1.48E-01 9.64E-02 C 

1,1,2-Trichloroethane 3 7.90E-03 4.08E-01 1.58E-01 2.18E-01 2.47E-01 D 

1,1-Dichloroethane 36 2.56E-02 1.59E+01 2.08E+00 2.87E+00 9.38E-01 A 

1,1-Dichloroethene (1,1­

Dichloroethylene) 34 2.06E-03 1.28E+00 1.60E-01 2.60E-01 8.74E-02 A 

1,2,3-Trimethylbenzene 3 2.69E-01 5.20E-01 3.59E-01 1.40E-01 1.58E-01 D 

1,2,4-Trichlorobenzene 6 1.01E-03 7.71E-03 5.51E-03 2.70E-03 2.16E-03 C 

1,2,4-Trimethylbenzene 13 1.95E-01 2.99E+00 1.37E+00 9.45E-01 5.14E-01 B 

1,2-Dibromoethane 

(Ethylene dibromide) 11 1.37E-03 1.90E-02 4.80E-03 5.39E-03 3.18E-03 B 

1,2-Dichloro-1,1,2,2­

tetrafluoroethane (Freon 114) 12 7.90E-03 4.23E-01 1.06E-01 1.15E-01 6.51E-02 B 

1,2-Dichloroethane (Ethylene 

dichloride) 34 1.03E-03 2.60E+00 1.59E-01 4.36E-01 1.46E-01 A 

1,2-Dichloroethene 1 1.14E+01 E 

1,2-Dichloropropane 4 7.35E-04 1.99E-01 5.20E-02 9.78E-02 9.58E-02 D 

1,2-Diethylbenzene 3 1.38E-02 2.52E-02 1.99E-02 5.75E-03 6.51E-03 D 

18
 
 

 

 

 

 

TABLE 2-8 (CONTINUED). LANDFILL GAS CONSTITUENTS 

Compound 

Number 

of Test 

Reports 

Minimum 

(ppm) 

Maximum 

(ppm) 

Mean 

(ppm) 

Standard 

Deviation 

(ppm) 

95% 

Confidence 

Interval 

(± ppm) 

Recommended 

Emission 

Factor Rating 

1,3,5-Trimethylbenzene 9 1.51E-01 1.09E+00 6.23E-01 3.59E-01 2.35E-01 C 

1,3-Butadiene (Vinyl 

ethylene) 7 2.27E-02 5.89E-01 1.66E-01 2.07E-01 1.53E-01 C 

1,3-Diethylbenzene 4 2.37E-02 1.30E-01 6.55E-02 4.53E-02 4.44E-02 D 

1,4-Diethylbenzene 4 9.50E-02 5.49E-01 2.62E-01 2.03E-01 1.99E-01 D 

1,4-Dioxane (1,4-Diethylene 

dioxide) 5 2.09E-03 1.39E-02 8.29E-03 4.50E-03 3.94E-03 D 

1-Butene / 2-Methylbutene 3 8.57E-01 1.42E+00 1.22E+00 3.12E-01 3.53E-01 D 

1-Butene / 2-Methylpropene 1 1.10E+00 E 

1-Ethyl-4-methylbenzene (4­

Ethyl toluene) 7 1.21E-01 2.85E+00 9.89E-01 1.21E+00 8.97E-01 C 

1-Ethyl-4-methylbenzene (4­

Ethyl toluene) + 1,3,5­

Trimethylbenzene 

4 8.17E-02 8.42E-01 5.79E-01 3.54E-01 3.46E-01 D 

1-Heptene 2 4.48E-01 8.03E-01 6.25E-01 2.51E-01 3.48E-01 E 

1-Hexene / 2-Methyl-1­

pentene 3 1.26E-02 2.22E-01 8.88E-02 1.16E-01 1.31E-01 D 

1-Methylcyclohexene 4 1.32E-02 3.89E-02 2.27E-02 1.16E-02 1.14E-02 D 

1-Methylcyclopentene 4 1.55E-02 4.62E-02 2.52E-02 1.45E-02 1.42E-02 D 

1-Pentene 4 3.23E-02 4.83E-01 2.20E-01 1.95E-01 1.91E-01 D 

1-Propanethiol (n-Propyl 

mercaptan) 22 1.46E-04 4.86E-01 1.25E-01 1.22E-01 5.11E-02 A 

2,2,3-Trimethylbutane 4 4.80E-03 1.41E-02 9.19E-03 3.86E-03 3.79E-03 D 

2,2,4-Trimethylpentane 5 3.21E-01 8.12E-01 6.14E-01 2.27E-01 1.99E-01 D 

2,2,5-Trimethylhexane 4 9.44E-02 2.50E-01 1.56E-01 7.29E-02 7.14E-02 D 

2,2-Dimethylbutane 4 9.56E-02 2.28E-01 1.56E-01 5.49E-02 5.38E-02 D 

2,2-Dimethylpentane 4 4.42E-02 7.30E-02 6.08E-02 1.27E-02 1.25E-02 D 

2,2-Dimethylpropane 1 2.74E-02 E 

2,3,4-Trimethylpentane 4 1.78E-01 4.73E-01 3.12E-01 1.35E-01 1.32E-01 D 

2,3-Dimethylbutane 4 1.43E-01 2.21E-01 1.67E-01 3.59E-02 3.52E-02 D 

2,3-Dimethylpentane 4 2.03E-01 3.76E-01 3.10E-01 7.70E-02 7.54E-02 D 

2,4-Dimethylhexane 4 1.74E-01 2.61E-01 2.22E-01 3.62E-02 3.54E-02 D 

2,4-Dimethylpentane 4 6.55E-02 1.21E-01 1.00E-01 2.42E-02 2.37E-02 D 

2,5-Dimethylhexane 4 1.33E-01 1.96E-01 1.66E-01 2.62E-02 2.57E-02 D 

2,5-Dimethylthiophene 1 6.44E-02 E 

2-Butanone (Methyl ethyl 

ketone) 8 2.81E-01 9.54E+00 4.01E+00 3.07E+00 2.12E+00 C 

2-Ethyl-1-butene 4 1.02E-02 2.68E-02 1.77E-02 6.98E-03 6.84E-03 D 

2-Ethylthiophene 1 6.29E-02 E 

2-Ethyltoluene 4 1.38E-01 6.53E-01 3.23E-01 2.29E-01 2.25E-01 D 

19
 
 

 

 

 

 

 

 

TABLE 2-8 (CONTINUED). LANDFILL GAS CONSTITUENTS 

Compound 

Number 

of Test 

Reports 

Minimum 

(ppm) 

Maximum 

(ppm) 

Mean 

(ppm) 

Standard 

Deviation 

(ppm) 

95% 

Confidence 

Interval 

(± ppm) 

Recommended 

Emission 

Factor Rating 

2-Hexanone (Methyl butyl 

ketone) 2 5.73E-01 6.53E-01 6.13E-01 5.65E-02 7.83E-02 E 

2-Methyl-1-butene 4 7.17E-02 3.47E-01 1.79E-01 1.18E-01 1.16E-01 D 

2-Methyl-1-propanethiol 

(Isobutyl mercaptan) 1 1.70E-01 E 

2-Methyl-2-butene 4 2.07E-01 4.12E-01 3.03E-01 1.03E-01 1.01E-01 D 

2-Methyl-2-propanethiol 

(tert-Butylmercaptan) 1 3.25E-01 E 

2-Methylbutane 4 2.80E-01 7.33E+00 2.26E+00 3.39E+00 3.32E+00 D 

2-Methylheptane 4 6.01E-01 9.50E-01 7.16E-01 1.61E-01 1.57E-01 D 

2-Methylhexane 4 5.58E-01 1.02E+00 8.16E-01 2.11E-01 2.07E-01 D 

2-Methylpentane 4 5.51E-01 1.00E+00 6.88E-01 2.13E-01 2.09E-01 D 

2-Propanol (Isopropyl 

alcohol) 6 1.17E-01 5.72E+00 1.80E+00 2.08E+00 1.66E+00 C 

3,6-Dimethyloctane 4 5.38E-01 1.01E+00 7.85E-01 1.99E-01 1.95E-01 D 

3-Ethyltoluene 4 3.55E-01 1.54E+00 7.80E-01 5.45E-01 5.34E-01 D 

3-Methyl-1-pentene 3 4.33E-03 1.09E-02 6.99E-03 3.44E-03 3.89E-03 D 

3-Methylheptane 4 6.25E-01 1.04E+00 7.63E-01 1.91E-01 1.87E-01 D 

3-Methylhexane 4 7.44E-01 1.41E+00 1.13E+00 3.16E-01 3.10E-01 D 

3-Methylpentane 4 5.72E-01 1.08E+00 7.40E-01 2.38E-01 2.34E-01 D 

3-Methylthiophene 1 9.25E-02 E 

4-Methyl-1-pentene 1 2.33E-02 E 

4-Methyl-2-pentanone 

(MIBK) 7 7.77E-02 1.99E+00 8.83E-01 6.63E-01 4.91E-01 C 

4-Methylheptane 4 1.90E-01 3.14E-01 2.49E-01 5.36E-02 5.25E-02 D 

Acetaldehyde 5 2.19E-02 1.65E-01 7.74E-02 6.31E-02 5.53E-02 D 

Acetone 9 3.38E-01 1.61E+01 6.70E+00 5.34E+00 3.49E+00 C 

Acetonitrile 20 1.35E-01 2.56E+00 5.56E-01 5.19E-01 2.27E-01 A 

Acrylonitrile 6 BDLa C 

Benzene 41 7.52E-02 2.20E+01 2.40E+00 3.69E+00 1.13E+00 A 

Benzyl chloride 24 1.72E-03 2.96E-02 1.81E-02 8.16E-03 3.26E-03 A 

Bromodichloromethane 2 2.75E-03 1.48E-02 8.78E-03 8.54E-03 1.18E-02 E 

Bromomethane (Methyl 

bromide) 7 2.36E-03 6.77E-02 2.10E-02 2.32E-02 1.72E-02 C 

Butane 9 4.31E-01 3.48E+01 6.22E+00 1.09E+01 7.10E+00 C 

Carbon disulfide 34 2.92E-04 3.53E-01 1.47E-01 8.74E-02 2.94E-02 A 

Carbon tetrachloride 30 8.55E-04 3.29E-02 7.98E-03 7.59E-03 2.72E-03 A 

Carbon tetrafluoride (Freon 

14) 1 1.51E-01 E 

Carbonyl sulfide (Carbon 

oxysulfide) 29 1.04E-04 2.75E-01 1.22E-01 7.12E-02 2.59E-02 A 

20
 
 

 

 

TABLE 2-8 (CONTINUED). LANDFILL GAS CONSTITUENTS 

Compound 

Number 

of Test 

Reports 

Minimum 

(ppm) 

Maximum 

(ppm) 

Mean 

(ppm) 

Standard 

Deviation 

(ppm) 

95% 

Confidence 

Interval 

(± ppm) 

Recommended 

Emission 

Factor Rating 

Chlorobenzene 37 1.79E-02 7.44E+00 4.84E-01 1.21E+00 3.89E-01 A 

Chlorodifluoromethane 

(Freon 22) 4 2.06E-01 1.39E+00 7.96E-01 5.00E-01 4.90E-01 D 

Chloroethane (Ethyl 

chloride) 10 9.69E-02 2.79E+01 3.95E+00 8.60E+00 5.33E+00 B 

Chloromethane (Methyl 

chloride) 11 1.24E-02 1.16E+00 2.44E-01 3.28E-01 1.94E-01 B 

cis-1,2-Dichloroethene 17 5.27E-02 6.69E+00 1.24E+00 1.56E+00 7.40E-01 B 

cis-1,2-Dimethylcyclohexane 4 5.68E-02 1.03E-01 8.10E-02 1.90E-02 1.86E-02 D 

cis-1,3-Dichloropropene 4 2.33E-04 6.68E-03 3.03E-03 2.72E-03 2.66E-03 D 

cis-1,3-Dimethylcyclohexane 4 3.78E-01 6.36E-01 5.01E-01 1.25E-01 1.23E-01 D 

cis-1,4-Dimethylcyclohexane 

/ trans-1,3­

Dimethylcyclohexane 

4 2.00E-01 2.91E-01 2.48E-01 3.97E-02 3.89E-02 D 

cis-2-Butene 4 7.08E-02 1.58E-01 1.05E-01 3.94E-02 3.86E-02 D 

cis-2-Heptene 1 2.45E-02 E 

cis-2-Hexene 4 8.54E-03 2.51E-02 1.72E-02 7.16E-03 7.02E-03 D 

cis-2-Octene 4 1.67E-01 2.78E-01 2.20E-01 5.66E-02 5.55E-02 D 

cis-2-Pentene 4 2.14E-02 7.47E-02 4.79E-02 2.37E-02 2.32E-02 D 

cis-3-Methyl-2-pentene 4 1.18E-02 2.43E-02 1.79E-02 5.92E-03 5.80E-03 D 

CO 6 4.75E+00 7.81E+01 2.44E+01 2.85E+01 2.28E+01 C 

Cyclohexane 10 1.19E-01 3.03E+00 1.01E+00 8.97E-01 5.56E-01 B 

Cyclohexene 4 1.43E-02 2.56E-02 1.84E-02 5.19E-03 5.09E-03 D 

Cyclopentane 4 1.27E-02 3.34E-02 2.21E-02 8.55E-03 8.38E-03 D 

Cyclopentene 4 5.13E-03 2.78E-02 1.21E-02 1.07E-02 1.05E-02 D 

Decane 4 1.85E+00 6.38E+00 3.80E+00 1.94E+00 1.90E+00 D 

Dibromochloromethane 3 7.95E-03 2.38E-02 1.51E-02 8.02E-03 9.08E-03 D 

Dibromomethane (Methylene 

dibromide) 2 6.37E-04 1.03E-03 8.35E-04 2.81E-04 3.89E-04 E 

Dichlorobenzene 58 4.84E-04 5.54E+00 9.40E-01 1.32E+00 3.40E-01 A 

Dichlorodifluoromethane 

(Freon 12) 13 1.17E-01 6.56E+00 1.18E+00 1.72E+00 9.34E-01 B 

Dichloromethane (Methylene 

chloride) 42 5.09E-03 4.12E+01 6.15E+00 8.23E+00 2.49E+00 A 

Diethyl sulfide 1 8.62E-02 E 

Dimethyl disulfide 25 2.29E-04 4.35E-01 1.37E-01 1.03E-01 4.02E-02 A 

Dimethyl sulfide 29 7.51E-03 1.47E+01 5.66E+00 3.83E+00 1.39E+00 A 

Dodecane (n-Dodecane) 4 6.79E-02 4.64E-01 2.21E-01 1.70E-01 1.66E-01 D 

Ethane 5 4.83E+00 1.40E+01 9.05E+00 4.23E+00 3.71E+00 D 

Ethanol 5 2.03E-02 3.40E-01 2.30E-01 1.39E-01 1.21E-01 D 

Ethyl acetate 6 1.63E-01 3.97E+00 1.88E+00 1.54E+00 1.23E+00 C 

21
 
 

 

 

TABLE 2-8 (CONTINUED). LANDFILL GAS CONSTITUENTS 

Compound 

Number 

of Test 

Reports 

Minimum 

(ppm) 

Maximum 

(ppm) 

Mean 

(ppm) 

Standard 

Deviation 

(ppm) 

95% 

Confidence 

Interval 

(± ppm) 

Recommended 

Emission 

Factor Rating 

Ethyl mercaptan (Ethanediol) 30 6.05E-05 8.35E-01 1.98E-01 1.97E-01 7.06E-02 A 

Ethyl methyl sulfide 1 3.67E-02 E 

Ethylbenzene 16 5.93E-01 8.80E+00 4.86E+00 2.58E+00 1.27E+00 B 

Formaldehyde 5 3.40E-03 2.51E-02 1.17E-02 9.32E-03 8.17E-03 D 

Heptane 10 1.29E-01 3.09E+00 1.34E+00 9.90E-01 6.14E-01 B 

Hexane 17 1.19E-01 2.60E+01 3.10E+00 6.04E+00 2.87E+00 B 

Hydrogen sulfide 36 1.02E-03 3.34E+02 3.20E+01 5.57E+01 1.82E+01 A 

Indan (2,3-Dihydroindene) 4 2.38E-02 1.39E-01 6.66E-02 5.12E-02 5.02E-02 D 

Isobutane (2-Methylpropane) 4 1.95E+00 1.66E+01 8.16E+00 6.73E+00 6.59E+00 D 

Isobutylbenzene 4 1.66E-02 7.55E-02 4.07E-02 2.49E-02 2.44E-02 D 

Isoprene (2-Methyl-1,3­

butadiene) 3 1.16E-02 2.21E-02 1.65E-02 5.28E-03 5.97E-03 D 

Isopropyl mercaptan 24 3.75E-05 1.22E+00 1.75E-01 2.60E-01 1.04E-01 A 

Isopropylbenzene (Cumene) 5 7.61E-02 9.60E-01 4.30E-01 3.50E-01 3.07E-01 D 

Methanethiol (Methyl 

mercaptan) 29 9.80E-04 4.05E+00 1.37E+00 9.55E-01 3.48E-01 A 

Methyl tert-butyl ether 

(MTBE) 5 3.30E-03 2.61E-01 1.18E-01 1.21E-01 1.06E-01 D 

Methylcyclohexane 4 1.00E+00 1.51E+00 1.29E+00 2.59E-01 2.54E-01 D 

Methylcyclopentane 4 4.01E-01 8.17E-01 6.50E-01 1.77E-01 1.74E-01 D 

Naphthalene 4 7.91E-03 2.65E-01 1.07E-01 1.19E-01 1.17E-01 D 

n-Butylbenzene 4 2.24E-02 1.40E-01 6.80E-02 5.12E-02 5.02E-02 D 

Nonane 4 1.62E+00 3.46E+00 2.37E+00 7.95E-01 7.79E-01 D 

n-Propylbenzene 

(Propylbenzene) 5 1.32E-01 7.07E-01 4.13E-01 2.35E-01 2.06E-01 D 

Octane 4 8.46E-01 1.38E+00 1.08E+00 2.73E-01 2.68E-01 D 

p-Cymene (1-Methyl-4­

lsopropylbenzene) 5 1.28E+00 8.16E+00 3.58E+00 3.10E+00 2.72E+00 D 

Pentane 9 4.77E-01 2.44E+01 4.46E+00 7.56E+00 4.94E+00 C 

Propane 9 4.79E+00 3.67E+01 1.55E+01 1.04E+01 6.80E+00 C 

Propene 4 1.61E+00 4.80E+00 3.32E+00 1.41E+00 1.38E+00 D 

Propyne 1 3.80E-02 E 

sec-Butylbenzene 4 2.64E-02 1.21E-01 6.75E-02 4.04E-02 3.96E-02 D 

Styrene (Vinylbenzene) 14 9.59E-03 1.21E+00 4.11E-01 4.49E-01 2.35E-01 B 

Tetrachloroethylene 

(Perchloroethylene) 40 5.12E-03 8.28E+00 2.03E+00 1.89E+00 5.85E-01 A 

Tetrahydrofuran (Diethylene 

oxide) 7 1.57E-01 1.78E+00 9.69E-01 5.63E-01 4.17E-01 C 

Thiophene 2 1.25E-01 5.72E-01 3.49E-01 3.16E-01 4.38E-01 E 

Toluene (Methyl benzene) 40 1.30E+00 9.08E+01 2.95E+01 2.30E+01 7.12E+00 A 

22
 
 

 

TABLE 2-8 (CONTINUED). LANDFILL GAS CONSTITUENTS 

Compound 

Number 

of Test 

Reports 

Minimum 

(ppm) 

Maximum 

(ppm) 

Mean 

(ppm) 

Standard 

Deviation 

(ppm) 

95% 

Confidence 

Interval 

(± ppm) 

Recommended 

Emission 

Factor Rating 

trans-1,2-Dichloroethene 8 3.09E-03 4.60E-02 2.87E-02 1.52E-02 1.05E-02 C 

trans-1,2­

Dimethylcyclohexane 4 3.19E-01 5.23E-01 4.04E-01 8.65E-02 8.47E-02 D 

trans-1,3-Dichloropropene 5 3.30E-04 3.00E-02 9.43E-03 1.18E-02 1.03E-02 D 

trans-1,4­

Dimethylcyclohexane 4 1.68E-01 2.50E-01 2.05E-01 4.12E-02 4.04E-02 D 

trans-2-Butene 4 5.41E-02 1.76E-01 1.04E-01 5.15E-02 5.05E-02 D 

trans-2-Heptene 1 2.50E-03 E 

trans-2-Hexene 4 1.11E-02 3.29E-02 2.06E-02 9.49E-03 9.30E-03 D 

trans-2-Octene 4 1.69E-01 2.96E-01 2.41E-01 5.32E-02 5.21E-02 D 

trans-2-Pentene 4 1.66E-02 5.09E-02 3.47E-02 1.41E-02 1.39E-02 D 

trans-3-Methyl-2-pentene 4 9.91E-03 2.07E-02 1.55E-02 4.73E-03 4.63E-03 D 

Tribromomethane 

(Bromoform) 4 4.36E-04 2.68E-02 1.24E-02 1.12E-02 1.09E-02 D 

Trichloroethylene 

(Trichloroethene) 42 6.55E-03 3.18E+00 8.28E-01 6.88E-01 2.08E-01 A 

Trichlorofluoromethane 

(Freon 11) 16 7.10E-03 7.14E-01 2.48E-01 2.22E-01 1.09E-01 B 

Trichloromethane 

(Chloroform) 34 2.21E-03 6.82E-01 7.08E-02 1.46E-01 4.91E-02 A 

Undecane 4 6.45E-01 3.10E+00 1.67E+00 1.04E+00 1.02E+00 D 

Vinyl acetate 6 2.17E-02 1.02E+00 2.48E-01 3.86E-01 3.09E-01 C 

Vinyl chloride 

(Chloroethene) 40 6.78E-03 1.72E+01 1.42E+00 2.88E+00 8.92E-01 A 

Xylenes (o-, m-, p-, 

mixtures) 78 3.09E-01 3.56E+01 9.23E+00 8.84E+00 1.96E+00 A 

a

 All tests below detection limit. Method detection limits are available for three tests, and are as follows: 2.00E-04, 4.00E03, and 2.00E-02 ppm 

23
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

TABLE 2-9. SUMMARY OF METHANE, CARBON MONOXIDE, CARBON DIOXIDE,
 

NITROGEN, AND OXYGEN CONCENTRATIONS OF RAW LANDFILL GAS 

Test 

Report ID 

CH4 CO CO2 N2 O2 

(ppmv) (% v/v) (ppmv) (% v/v) (ppmv) (% v/v) (ppmv) (% v/v) (ppmv) (% v/v) 

TR-076 NRa NR NR NR NR NR 160,500 16.1 16,700 1.7 

TR-084 NR NR NR NR NR NR 100,000 10.0 24,000 2.4 

TR-086 NR NR NR NR NR NR 21,700 2.2 10,000 1.0 

TR-114 NR NR NR NR NR NR 140,000 14.0 NR NR 

TR-134 NR NR NR NR NR NR 27,850 2.8 2,500 0.3 

TR-141 NR NR NR NR NR NR 50,100 5.0 20,500 2.1 

TR-145 50,600 51.0 13 0.0 407,400 40.7 71,400 7.1 11,100 1.1 

TR-146 525,000 52.5 NR NR 413,000 41.3 56,900 5.7 4,280 0.4 

TR-147 NR NR 2.7 0.0 NR NR NR NR NR NR 

TR-148 529,000 52.9 4.7 0.0 402,000 40.2 66,000 6.6 2,700 0.3 

TR-153 547,000 54.7 NR NR 380,000 38.0 80,000 8.0 6,000 0.6 

TR-156 389,000 38.9 NR NR 349,000 34.9 258,000 25.8 24,000 2.4 

TR-157 581,000 58.1 NR NR 386,000 38.6 27,000 2.7 2,800 0.3 

TR-159 480,000 48.0 NR NR 374,000 37.4 141,000 14.1 5,300 0.5 

TR-165 443,000 44.3 NR NR 356,000 35.6 180,000 18.0 15,200 1.5 

TR-167 450,000 45.0 NR NR 360,000 36.0 178,000 17.8 14,400 1.4 

TR-168 335,000 33.5 NR NR 326,000 32.6 324,000 32.4 21,000 2.1 

TR-169 316,000 31.6 NR NR 316,000 31.6 340,000 34.0 22,000 2.2 

TR-171 359,000 35.9 NR NR 405,000 40.5 209,000 20.9 22,000 2.2 

TR-173 481,000 48.1 NR NR 382,000 38.2 121,000 12.1 17,400 1.7 

TR-175 379,000 37.9 5.2 0.0 301,000 30.1 235,000 23.5 62,100 6.2 

TR-176 318,000 31.8 NR NR 265,000 26.5 344,000 34.4 73,300 7.3 

TR-178 200,000 20.0 NR NR 247,000 24.7 519,000 51.9 34,000 3.4 

TR-179 459,000 45.9 NR NR 331,000 33.1 NR NR 32,800 3.3 

TR-181 335,500 33.6 NR NR 324,000 32.4 306,000 30.6 23,800 2.4 

TR-182 351,000 35.1 NR NR 332,000 33.2 287,000 28.7 21,800 2.2 

TR-183 326,000 32.6 NR NR 309,000 30.9 341,000 34.1 24,000 2.4 

24
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

TABLE 2-9 (CONTINUED). SUMMARY OF METHANE, CARBON MONOXIDE, CARBON 

DIOXIDE, NITROGEN, AND OXYGEN CONCENTRATIONS OF RAW LANDFILL GAS 

Test CH4 CO CO2 N2 O2 

Report ID (ppmv) (% v/v) (ppmv) (% v/v) (ppmv) (% v/v) (ppmv) (% v/v) (ppmv) (% v/v) 

TR-187 350,000 35.0 NR NR 334,000 33.4 289,000 28.9 27,000 2.7 

TR-188 435,000 43.5 77 0.0 355,000 35.5 196,000 19.6 13,700 1.4 

TR-189 557,000 55.7 35 0.0 405,000 40.5 37,700 3.8 300 0.0 

TR-190 502,000 50.2 NR NR 395,000 39.5 103,000 10.3 200 0.0 

TR-191 350,000 35.0 NR NR 272,000 27.2 322,000 32.2 56,700 5.7 

TR-194 611,000 61.1 65 0.0 389,000 38.9 NR NR 1,000 0.1 

TR-196 476,000 47.6 NR NR 384,000 38.4 133,000 13.3 6,700 0.7 

TR-199 275,000 27.5 NR NR 212,000 21.2 427,000 42.7 86,000 8.6 

TR-205 345,000 34.5 NR NR 328,000 32.8 297,000 29.7 23,000 2.3 

TR-207 183,000 18.3 NR NR 219,500 22.0 506,000 50.6 91,800 9.2 

TR-209 483,000 48.3 0.0 0.0 387,000 38.7 118,000 11.8 10,900 1.1 

TR-220 350,000 35.0 NR NR 295,000 29.5 304,000 30.4 50,500 5.1 

TR-226 522,000 52.2 6.5 0.0 349,000 34.9 100,000 10.0 27,700 2.8 

TR-229 309,000 30.9 NR NR 250,000 25.0 374,000 37.4 72,200 7.2 

TR-241 212,000 21.2 NR NR 263,000 26.3 465,000 46.5 61,000 6.1 

TR-251 410,000 41.0 NR NR 366,000 36.6 190,000 19.0 35,000 3.5 

TR-253 440,000 44.0 NR NR 351,000 35.1 191,000 19.1 46,600 4.7 

TR-255 445,000 44.5 NR NR 375,000 37.5 164,000 16.4 16,000 1.6 

TR-259 257,000 25.7 NR NR 282,000 28.2 414,000 41.4 23,800 2.4 

TR-260 260,000 26.0 NR NR 284,000 28.4 415,000 41.5 24,000 2.4 

TR-261 259,000 25.9 NR NR 281,000 28.1 428,000 42.8 26,900 2.7 

TR-264 446,000 44.6 NR NR 374,000 37.4 154,000 15.4 26,500 2.7 

TR-266 311,000 31.1 0.0 0.0 304,000 30.4 NR NR 3,000 0.3 

TR-272 467,000 46.7 NR NR 374,000 37.4 131,000 13.1 17,000 1.7 

TR-273 376,000 37.6 NR NR 298,000 29.8 256,000 25.6 64,000 6.4 

TR-284 520,000 52.0 NR NR 411,000 41.1 159,000 15.9 16,000 1.6 

TR-287 617,000 61.7 NR NR 430,000 43.0 112,000 11.2 200 0.0 

25
 
 

 

 

 

 

 

 

 

 

 

 

 

 

TABLE 2-9 (CONTINUED). SUMMARY OF METHANE, CARBON MONOXIDE, CARBON 

DIOXIDE, NITROGEN, AND OXYGEN CONCENTRATIONS OF RAW LANDFILL GAS 

Test CH4 CO CO2 N2 O2 

Report ID (ppmv) (% v/v) (ppmv) (% v/v) (ppmv) (% v/v) (ppmv) (% v/v) (ppmv) (% v/v) 

TR-290 213,000 21.3 NR NR 348,000 34.8 420,000 42.0 8,800 0.9 

TR-292 495,000 49.5 NR NR 333,000 33.3 136,000 13.6 25,700 2.6 

TR-293a 607,000 60.7 NR NR 438,000 43.8 137,000 13.7 26,000 2.6 

TR-293b 432,000 43.2 NR NR 374,000 37.4 262,000 26.2 24,000 2.4 

Minimum 183,000 18.3 - - 212,000 21.2 21,700 2.2 200 0.0 

Maximum 617,000 61.7 77.0 0.0 438,000 43.8 519,000 51.9 91,800 9.2 

Mean 408,000 40.8 20.9 0.0 342,000 34.2 219,000 21.9 25,400 2.5 

Standard 

Deviation 113,000 11.3 28.4 0.0 54,800 5.5 135,000 13.5 22,100 2.2 

95% 

Confidence 

Interval 

(±) 31,100 3.1 17.6 0.0 15,000 1.5 35,900 3.6 5,790 0.6 

(a) Not reported 

References 

California Air Resources Board. Facsimile from Chris Holm to Susan Thorneloe, U.S. EPA. 

Otay Landfill Flare Gas Summary. July 19, 2005. 

TR-076. New Source Performance Standards Tier 2 Sampling and Analysis for the Flying Cloud 

Landfill, Browning-Ferris Industries, 6/30/98. 

TR-084. Tier 2 NMOC Emission Rate Report for the Buncombe County Landfill, Buncombe 

County Solid Waste Services, 5/12/99. 

TR-086. Tier 2 NMOC Emission Rate Report for the White Street Landfill, Duke Engineering 

and Services, City of Greensboro Solid Waste Management Division, 5/18/99. 

TR-114. Summary Report of Tier 2 Sampling, Analysis, and Landfill Emissions Estimates for 

Non-Methane Organic Compounds Chrin Brothers Landfill, Chrin Brothers Sanitary Landfill, 

4/24/98. 

TR-115. Seneca Landfill - Revised Tier 2 NMOC Emission Rate Report, Seneca Landfill, Inc., 

12/5/96. 

TR-134. New Source Performance Standards Tier 2 Sampling, Analysis, and Landfill NMOC 

Emission Estimates for the Fort Worth Landfill, Laidlaw Waste Systems, Inc., 4/15/97. 

TR-141. Tier 2 NMOC Emission Rate Report for the SPSA Regional Landfill, Southeastern 

Public Service Authority, MSA Consulting Engineers, 6/10/97. 

26
 
 

TR-145. Compliance Testing of a Landfill Flare at Browning-Ferris Gas Services, Inc.'s Facility 

in Halifax, Massachusetts, BFI Waste Systems of North America, Inc., May 1996. 

TR-146. Compliance Source Testing of a Landfill Flare at Northern Disposal, Inc. East 

Bridgewater Landfill, Northern Disposal, Inc., June 1994. 

TR-147. Compliance Emissions Test Program for BFI of Ohio, Inc., BFI of Ohio, Inc., 6/26/98.
 

TR-148. Compliance Testing of Landfill Flare at Browning-Ferris Gas Services, Inc.'s Fall River 

Landfill Flare, BFI Waste Systems of North America, Inc., March 1995. 

TR-153. Results of the Emission Compliance Test on the Enclosed Flare System at the Carbon 

Limestone Landfill, Browning-Ferris Industrial Gas Services, Inc., 8/8/96. 

TR-156. Results of the Emission Compliance Test on the Enclosed Flare System at the Lorain 

County Landfill No. 2, Browning-Ferris Industrial Gas Services, Inc., 9/5/96. 

TR-157. Emission Compliance Testing Browning-Ferris Gas Services, Inc. Willowcreek Landfill, 

BFI-Willowcreek, 2/2/98. 

TR-159. Compliance Stack Sampling Report, Monmouth County Reclamation Center, SCS 

Engineers (Reston, VA), 9/8/95. 

TR-160. Source Emission Testing of an Enclosed Landfill Gas Ground Flare, SCS Engineers 

(Reston, VA), September 1997. 

TR-165. 1997 Annual Compliance Source Testing Results for the Coyote Canyon Landfill Gas 

Recovery Facility Flare No. 1, Laidlaw Gas Recovery Systems, January 1998. 

TR-167. 1997 Annual Compliance Source Testing Results for the Coyote Canyon Landfill Gas 

Recovery Facility Boiler, Laidlaw Gas Recovery Systems, January 1998. 

TR-168. Colton Sanitary Landfill Gas Flare No. 2 (John Zink) 1998 Source Tests Results, Bryan 

A. Stirrat & Associates, 9/29/98. 

TR-169. Colton Sanitary Landfill Gas Flare No. 1 (McGill) 1998 Source Tests Results, Bryan A. 

Stirrat & Associates, 9/29/98. 

TR-171. High Landfill Gas Flow Rate Source Test Results from One Landfill Gas Flare at FRB 

Landfill in Orange County, California, Bryan A. Stirrat & Associates, July 1997. 

TR-173. Annual Emissions Test of Landfill Gas Flare #3 Bradley Landfill, Waste Management 

Recycling and Disposal Services of California, Inc., 4/12/99. 

TR-175. Emissions Tests on Flares #2, #4 and #6 at the Lopez Canyon Landfill, City of Los 

Angeles, August 1997. 

TR-176. Emissions Test Results on Flares #1, #4 and #9 Calabasas Landfill, County Sanitation 

Districts of Los Angeles County, February 1998. 

27
 
 

TR-178. Annual Emission Test of Landfill Gas Flare #3 Bradley Landfill, Waste Management 

Recycling and Disposal Services of California, Inc., 5/21/98. 

TR-179. Annual Emissions Test of Landfill Gas Flare #1 Bradley Landfill, Waste Management 

Recycling and Disposal Services of California, Inc., 4/13/99. 

TR-181. The Mid-Valley Sanitary Landfill Gas Flare No.1 (McGill) 1998 Source Test Results, 

Bryan A. Stirrat & Associates, 9/29/98. 

TR-182. The Mid-Valley Sanitary Landfill Gas Flare No.2 (SurLite) 1998 Source Test Results, 

Bryan A. Stirrat & Associates, 9/29/98. 

TR-183. Annual Emissions Test of Landfill Gas Flare #2 Bradley Landfill, Waste Management 

Recycling and Disposal Services of California, Inc., 4/13/99. 

TR-187. Emissions Test of a Landfill Gas Flare - Lowry Landfill/Denver-Arapohoe Disposal 

Site, Sur-Lite Corporation, February 1997. 

TR-188. Characterization of Emissions from a Power Boiler Fired with Landfill Gas, 

Environment Canada Emissions Research and Measurement Division, March 2000. 

TR-189. Characterization of Emissions from 925 kWe Reciprocating Engine Fired with Landfill 

Gas, Environment Canada Emissions Research and Measurement Division, 

December 2000. 

TR-190. Characterization of Emissions from 812 kWe Reciprocating Engine Fired with Landfill 

Gas, Environment Canada Emissions Research and Measurement Division, 

December 1999. 

TR-191. Characterization of Emissions from Enclosed Flare - Trail Road Landfill, Environment 

Canada Emissions Research and Measurement Division, August 2000. 

TR-194. Characterization of Emissions from 1 MWe Reciprocating Engine Fired with Landfill 

Gas, Environment Canada Emissions Research and Measurement Division, January 2002. 

TR-195. Characteristics of Semi-volatile Organic Compounds from Vented Landfills, 

Environment Canada Environmental Technology Advancement Directorate, August 1996. 

TR-196. Results of the Biennial Criteria and AB 2588 Air Toxics Source Test on the Simi Valley
 

Landfill Flare, Simi Valley Landfill and Recycling Center, April 1997. 

TR-199. Emission Compliance Test on a Landfill Flare, City of Los Angeles, January 1999. 

TR-205. The Mid-Valley Sanitary LFG Flare No. 3 (John Zink) 1998 Source Test Results, Bryan 

A. Stirrat & Associates, 9/29/98. 

TR-207. Compliance Source Test Report LFG-fired Flare Stations I-4 and F-2, BKK Landfill, 

12/12/97. 

TR-209. Emission Test Report Volumes I and II - Source/Compliance Emissions Testing for 

Cedar Hills Landfill, King County Solid Waste Division, 1/20/05. 

28
 
TR-220. SCAQMD Performance Tests on the Spadra Energy Recovery from LFG (SPERG) 

Facility, County Sanitation Districts of Los Angeles County, April 1992. 

TR-226. Methane and Nonmethane Organic Destruction Efficiency Tests of an Enclosed LFG 

Flare, Newco Waste Systems, April 1992. 

TR-229. Scholl Canyon Landfill Gas Flares No. 9, 10 11 and 12 Emission Source Testing April 

1999, South Coast Air Quality Management District, April 1999. 

TR-236. Landfill Gas Flare Hydrogen Chloride Emissons Atascocita Landfill, Waste 

Management of Houston, 4/20/99. 

TR-241. Performance Evaluation, Enclosed Landfill Gas Flare, Valley Landfill, Waste Energy 

Technology, November 1991. 

TR-251. Emission Compliance Test on a Landfill Gas Flare - Flare #1, Frank R. Bowerman 

Landfill, Orange County, 1/25/99. 

TR-253. Emission Source Testing on Two Flares (Nos. 3 and 6) at the Spadra Landfill, Los 

Angeles County Sanitation Districts, 7/21/98. 

TR-255. Emission Compliance Test on a Landfill Gas Flare -Olinda Alpha Landfill, Orange 

County Integrated Waste Management Department, No Report Date Given. 

TR-258. Source Test Report, City of Sacramento Landfill Gas Flare, City of Sacramento, 6/26/96. 

TR-259. The Millikan Sanitary Landfill Gas Flare No. 1 (Surlite) 1998 Source Test Results, 

South Coast Air Quality Management District, 9/29/98. 

TR-260. The Millikan Sanitary Landfill Gas Flare No. 2 (John Zink) 1998 Source Test Results, 

South Coast Air Quality Management District, 9/29/98. 

TR-261. The Millikan Sanitary Landfill Gas Flare No. 3 (John Zink) 1998 Source Test Results, 

South Coast Air Quality Management District, 9/29/98. 

TR-264. Emission Compliance Test on a Landfill Gas Flare, Orange County Integrated Waste 

Management Department, No Report Date Given. 

TR-266. Compliance Source Test Report - Landfill Gas-Fired Engine, Minnesota Methane, 

3/3/98. 

TR-272. Source Testing Final Report - Landfill A, US EPA Air Pollution Prevention and Control 

Division, 10/6/05. 

TR-273. Source Testing Final Report - Landfill B, US EPA Air Pollution Prevention and Control 

Division, 10/6/05. 

TR-284. Source Testing Final Report - Landfill C, US EPA Air Pollution Prevention and Control 

Division, 10/6/05. 

29
 
TR-287. Source Testing Final Report - Landfill D, US EPA Air Pollution Prevention and Control 

Division, 10/6/05. 

TR-290. San Timoteo Sanitary Landfill 1998 Source Test Results, San Bernandino County Solid 

Waste Management, 9/29/98. 

TR-292. Source Testing Final Report - Landfill E, US EPA Air Pollution Prevention and Control 

Division, October 2005. 

TR-293. Quantifying Uncontrolled Air Emissions From Two Florida Landfills – Draft Final 

Report. U.S. EPA Air Pollution Prevention and Control Division, March 26, 2008. 

U.S. Environmental Protection Agency (1997a). Procedures for Preparing Emission Factor 

Documents ,EPA-454/R-95-015, Office of Air Quality Planning and Standards, Research 

Triangle Park, NC, November 1997. 

U.S. Environmental Protection Agency (1997b). Emission Factor Documentation for AP-42 

Section 2.4 – Municipal Solid Waste Landfills, Revised, Office of Air Quality Planning and 

Standards. Research Triangle Park, NC, August 1997. 

30
 
2.7 LANDFILL GAS CONSTITUENT DATA FOR LANDFILLS WITH WASTE IN PLACE 

PRIOR TO 1992 

The prior Municipal Solid Waste (MSW) Landfills section of AP-42 (U.S. EPA, 1998) contained 

uncontrolled LFG constituent default emission factors derived from landfills with the majority of their 

waste in place prior to 1992. This data is retained in the AP-42 section as Table 2.4-2. The following 

discussion, adapted from the 1997 emission factor documentation report (U.S. EPA, 1997b), documents 

the prior activities and analysis performed to derive these emission factors. The supporting raw data 

tables from the 1997 report are provided in Appendix A. 

2.7.1 Data Gathering and Review 

Data gathering was undertaken in advance of the 1998 AP-42 section update. This data gathering 

effort included an extensive literature search, contacts to identify ongoing projects within EPA, and 

electronic database searches. MSW landfill source test reports were collected during these efforts. After 

the data gathering was completed, a review of the information obtained was undertaken to reduce and 

synthesize the information for emission factor development. 

Reduction of the collected literature and data into a smaller, more pertinent subset for 

development of the MSW Landfill AP-42 section was governed by the following: 

•	 Only primary references of emissions data were used. 

•	 Test report source processes were clearly identified. 

•	 Test reports specified whether emissions were controlled or uncontrolled. 

•	 Reports referenced for controlled emissions specify the control devices. 

•	 Data support (i.e., calculation sheets, sampling and analysis description) was supplied in most cases. 

One exception is that some industry responses to the NSPS surveys were deemed satisfactory for 

inclusion. 

•	 Test report units were convertible to selected reporting units. 

•	 Test reports that were positively biased to a particular situation (i.e., test studies involving PCB 

analysis because of a known historical problem associated with PCB disposal in a specific MSW 

landfill) were excluded. 

As delineated by EPA’s Emission Inventory Branch (EIB), the reduced subset of emissions data was 

ranked for quality. The ranking/rating of the data was used to identify questionable data. Each data set 

was ranked as follows: 

A - When tests were performed by a sound methodology and reported in enough detail for 

adequate validation. These tests are not necessarily EPA reference method tests, although 

such reference methods were preferred. 

B - When tests were performed by a generally sound methodology, but lack enough detail for 

adequate validation. 

C - When tests were based on an untested or new methodology or are lacking a significant amount 

of background data. 

D - When tests were based on a generally unacceptable method but the method may provide an 

order-of-magnitude value for the source (U.S. EPA, 1993). 

The selected rankings were based on the following criteria: 

31
 
 

•	 Source operation. The manner in which the source was operated is well documented in the report. 

The source was operating within typical parameters during the test. 

•	 Sampling procedures. If actual procedures deviated from standard methods, the deviations are well 

documented. Procedural alterations are often made in testing an uncommon type of source. When 

this occurs an evaluation is made of how such alternative procedures could influence the test results. 

•	 Sampling and process data. Many variations can occur without warning during testing, sometimes 

without being noticed. Such variations can induce wide deviation in sampling results. If a large 

spread between test results cannot be explained by information contained in the test report, the data 

are suspect and are given a lower rating. 

•	 Analysis and calculations. The test reports contain original raw data sheets. The nomenclature and 

equations used are compared with those specified by the EPA, to establish equivalency. The depth of 

review of the calculations is dictated by the reviewers' confidence in the ability and conscientiousness 

of the tester, which in turn is based on factors such as consistency of results and completeness of 

other areas of the test report (U.S. EPA, 1993). 

2.7.2 Development of Default Concentrations 

After review, there were 110 data sources (identified in the references as BID-1 to BID-110) used 

to develop the default concentrations. Appendix A lists the compounds presented in each reference. The 

Appendix also reflects the co-disposal history of the landfill, if known. Landfills known to have accepted 

non-residential wastes (i.e., co-disposal) and those known to have never accepted non-residential wastes 

are delineated. For most of these landfills, the disposal history is unknown. The data for co-disposal and 

no co-disposal or unknown disposal history are separated for NMOC, benzene, and toluene. There was 

no statistical difference among disposal history for any of the other LFG constituents presented (U.S. 

EPA, 1997b). As mentioned before, RCRA subtitle D requirements resulted in eliminating the practice of 

co-disposal in municipal solid waste landfills, so that co-disposal data segregation is not an issue for the 

landfills with waste in place on or after 1992. 

Table 2-11 presents default concentration values for the speciated organic compounds and 

reduced sulfur compounds that were corrected for air infiltration. As discussed earlier, these data were 

presented in the previous version of the AP-42 chapter (U.S. EPA, 1998), and will be presented in the 

AP-42 chapter as default concentrations for landfills with waste in place prior to 1992. The following 

criteria, used in developing ratings in the 1997 AP-42 update (U.S. EPA, 1997b), were used to provide 

recommended default emission factor ratings. 

TABLE 2-10. CRITERIA USED TO DETERMINE RECOMMENDED DEFAULT EMISSION 

FACTOR RATINGS 

Factor Rating # of Data Points 

A ≥ 20 

B 10-19 

C 6-9 

D 3-5 

E <3 

32
 
 

 

TABLE 2-11. DEFAULT CONCENTRATIONS FOR LFG CONSTITUENTS FOR LANDFILLS 

WITH WASTE IN PLACE PRIOR TO 1992
 

Compound Molecular Weight 

Default 

Concentration 

(ppmv) 

Emission Factor 

Rating 

NMOC (as hexane)e 86.18 

 Co-disposal (SCC 50300603) 2,420 D

 No or Unknown co-disposal (SCC 50100402) 595 B 

1,1,1-Trichloroethane (methyl chloroform)a

 133.42 0.48 B 

1,1,2,2-Tetrachloroethanea

 167.85 1.11 C 

1,1-Dichloroethane (ethylidene dichloride)a

 98.95 2.35 B 

1,1-Dichloroethene (vinylidene chloride)a

 96.94 0.20 B 

1,2-Dichloroethane (ethylene dichloride)a

 98.96 0.41 B 

1,2-Dichloropropane (propylene dichloride)a

 112.98 0.18 D 

2-Propanol (isopropyl alcohol) 60.11 50.1 E 

Acetone 58.08 7.01 B 

Acrylonitrilea

 53.06 6.33 D 

Benzenea

 78.11 

 Co-disposal (SCC 50300603) 11.1 D

 No or Unknown co-disposal (SCC 50100402) 1.91 B 

Bromodichloromethane 163.83 3.13 C 

Butane 58.12 5.03 C 

Carbon disulfidea

 76.13 0.58 C 

Carbon monoxideb

 28.01 141 E 

Carbon tetrachloridea

 153.84 0.004 B 

Carbonyl sulfidea

 60.07 0.49 D 

Chlorobenzenea

 112.56 0.25 C 

Chlorodifluoromethane 86.47 1.30 C 

Chloroethane (ethyl chloride)a

 64.52 1.25 B 

Chloroforma

 119.39 0.03 B 

Chloromethane 50.49 1.21 B 

Dichlorobenzenec

 147 0.21 E 

Dichlorodifluoromethane 120.91 15.7 A 

Dichlorofluoromethane 102.92 2.62 D 

Dichloromethane (methylene chloride)a

 84.94 14.3 A 

Dimethyl sulfide (methyl sulfide) 62.13 7.82 C 

Ethane 30.07 889 C 

Ethanol 46.08 27.2 E 

Ethyl mercaptan (ethanethiol) 62.13 2.28 D 

Ethylbenzenea

 106.16 4.61 B 

Ethylene dibromide 187.88 0.001 E 

Fluorotrichloromethane 137.38 0.76 B 

33
 
 

 

 

 

Table 2-11 (CONTINUED). DEFAULT CONCENTRATIONS FOR LFG CONSTITUENTS FOR 

LANDFILLS WITH WASTE IN PLACE PRIOR TO 1992
 

Compound Molecular Weight 

Default 

Concentration 

(ppmv) 

Emission Factor 

Rating 

Hexanea

 86.18 6.57 B 

Hydrogen sulfide 34.08 35.5 B 

Mercury (total)a,d 200.61 2.92x10-4 E 

Methyl ethyl ketonea 72.11 7.09 A 

Methyl isobutyl ketonea 100.16 1.87 B 

Methyl mercaptan 48.11 2.49 C 

Pentane 72.15 3.29 C 

Perchloroethylene (tetrachloroethylene)a 165.83 3.73 B 

Propane 44.09 11.1 B 

t-1,2-dichloroethene 96.94 2.84 B 

Toluenea

 92.13 

 Co-disposal (SCC 50300603) 165 D

 No or Unknown co-disposal (SCC 50100402) 39.3 A 

Trichloroethylene (trichloroethene)a 131.38 2.82 B 

Vinyl chloridea 62.50 7.34 B 

Xylenesa 106.16 12.1 B 

NOTE: This is not an all-inclusive list of potential LFG constituents, only those for which test data were available 

at multiple sites. 

a

 Hazardous Air Pollutants listed in Title III of the 1990 Clean Air Act Amendments. 

b

 Carbon monoxide is not a typical constituent of LFG, but does exist in instances involving landfill (underground) 

combustion. Therefore, this default value should be used with caution. Of 18 sites where CO was measured, only 2 

showed detectable levels of CO. 

c

 Source tests did not indicate whether this compound was the para- or ortho- isomer. The para isomer is a Title IIIlisted HAP. 

d

 No data were available to speciate total Hg into the elemental and organic forms. e

 For NSPS/Emission Guideline compliance purposes, the default concentration for NMOC as specified in the final 

rule must be used. For purposes not associated with NSPS/Emission Guideline compliance, the default VOC 

content at co-disposal sites can be estimated by 85% by weight (2,060 ppmv as hexane); at No or Unknown sites 

can be estimated by 39% by weight (235 ppmv as hexane).
 

References 

BID-1. Source Test Report No. 86-0375, Vinyl Chloride, Benzene, Toluene (and other Selected 

Chlorinated Hydrocarbon Compounds) Present in Landfill Gas Before and After Flaring, South 

Coast Air Quality Management District, October 29, 1986. 

BID-2. Hazardous Pollutants in Class II Landfills, J.A. Wood and M.L. Porter, South Coast Air 

Quality Management District, December 1986. 

BID-3. Emissions from a Landfill Gas-Fired Turbine/Generator Set, March 6, 1984, Source Test 

Report C-84-33 conducted at L.A. County Sanitation District by South Coast Air Quality 

Management District, June 28, 1984. 

34
 
 

BID-4. Report of Stack Testing at County Sanitation District of Los Angeles Puente Hills 

landfill, July 31 and August 3, 1984, prepared by Engineering-Science for County Sanitation 

District of Los Angeles, August 15, 1984. 

BID-5. Vinyl Chloride (and Other Organic Compounds) Content of Landfill Gas Vented to an 

Inoperative Flare, October 15, 1984, Source Test Report 84-496 conducted at David Price 

company by South Coast Air Quality Management District, November 30, 1984. 

BID-6. Landfill Gas Composition, February 15, 1985, Source Test Report 85-102 Conducted at 

Bradley Pit Landfill by South Coast Air Quality Management District, May 22, 1985. 

BID-7. Vinyl Chloride and Other Selected Compounds Present in A Landfill Gas Collection 

System Prior to and after Flaring, July 31, 1985, Source Test Report 85-369, conducted at L.A. 

County Sanitation District by South Coast Air Quality Management District, October 9, 1985. 

BID-8. Emissions from a Landfill Exhausting Through a Flare System, September 11, 1985, 

Source Test Report 85-461, conducted at Operating Industries by South Coast Air Quality 

Management District, October 14, 1985. 

BID-9. Emissions from a Landfill Gas Collection System, November 5, 1985, Source Test 

Report 85-511, conducted at Sheldon Street Landfill by South Coast Air Quality Management 

District, December 9, 1985. 

BID-10. Vinyl Chloride and Other Selected Compounds Present in a Landfill Gas Collection 

System Prior to and after Flaring, December 6, 1985, Source Test Report 85-597, conducted at 

L.A. County Sanitation District's Mission Canyon Landfill by South Coast Air Quality 

Management District, January 16, 1986. 

BID-11. Emissions from a Landfill Gas-Fired Flare and Sales Gas Constituents from a Landfill 

Gas Treatment Plant, May 7, 1986, Source Test Report 86-220, conducted at Azusa Land 

Reclamation by South Coast Air Quality Management District, June 30, 1986. 

BID-12. Evaluation Test on a Landfill Gas-Fired Flare at the BKK Landfill Facility, West 

Covina, California, ARB-SS-87-09, California Air Resources Board, July 1986. 

BID-13. Gaseous Composition from a Landfill Gas Collection System and Flare, July 10, 1986, 

Source Test Report 86-0342, conducted at Syufy Enterprises by South Coast Air Quality 

Management District, August 21, 1986. 

BID-14. Emissions for Flare #3 Inlet Fuel Gas Line, April 1, 1987, Source Test Summary 

87-0110, conducted at Pacific Lighting Energy Systems (Penrose Landfill) by South Coast Air 

Quality Management District, August 5, 1987. 

BID-15. Analytical Laboratory Report for Source Test, Azusa Land Reclamation, June 30, 1983, 

South Coast Air Quality Management District. 

BID-16. Analytical Laboratory Report for Source Test, Mission Canyon Landfill, West L.A. and 

Mountain Gate, April 11, 1984, South Coast Air Quality Management District. 

BID-17. Source Test Report C-84-202, Bradley Pit Landfill, May 25, 1984, South Coast Air 

Quality Management District. 

35
 
 

BID-18. Source Test Report 84-315, Puente Hills Landfill, February 6, 1985, South Coast Air 

Quality Management District. 

BID-19. Source Test Report 84-596, Bradley Pit Landfill, March 11, 1985, South Coast Air 

Quality Management District. 

BID-20. Source Test Report 84-373, L.A. By-Products, March 27, 1985, South Coast air Quality 

Management District. 

BID-21. Source Test Report 85-36, Azusa Land Reclamation, August 13, 1985, South Coast Air 

Quality Management District. 

BID-22. Source Test Report 85-403, Palos Verdes Landfill, September 25, 1985, South Coast 

Air Quality Management District. 

BID-23. Source Test Report 86-0234, Pacific Lighting Energy Systems, July 16, 1986, South 

Coast Air Quality Management District. 

BID-24. Evaluation Test on a Landfill Gas-Fired Flare at the Los Angeles County Sanitation 

District's Puente Hills Landfill Facility, CA, July 1986, [ARB/SS-87-06], South Coast Air 

Quality Management District, Sacramento, CA, July 1986. 

BID-25. Gas Characterization, Microbial Analysis, and Disposal of Refuse in GRI Landfill 

Simulators, [EPA/600/2-86/041], Hazardous Waste Engineering Research Laboratory, Cincinnati, 

OH, April 1986. 

BID-26. Analysis of Factors Affecting Methane Gas Recovery from Six Landfills, [EPA-600/2­

91-055], U.S. Environmental Protection Agency, Air and Energy Engineering Research 

Laboratory, Research Triangle Park, NC, September 1991. 

BID-27. Source Test Report, Browning-Ferris Industries, Lyon Development Landfill, 

August 21, 1990. 

BID-28. Source Test Report, Browning-Ferris Industries, Azusa Landfill. 

BID-29. Municipal Landfill Gas Condensate, EPA/600/2-87/090, U.S. Environmental Protection 

Agency, Office of Research and Development, Cincinnati, OH, October 1987. 

BID-30. Measurement of Fugitive Atmospheric Emissions of Polychlorinated Biphenyls from 

Hazardous Waste Landfills, Environmental Science and Technology, v19n10 p 986-991. October 

1985. 

BID-31. Barboza M.J., P.E., Air Emissions Study of the Blydenburgh Road Landfill, Paulus 

Sokolowski and Sartor, Inc., Malcolm Pirnie, Inc, Mahwah, NJ, April 13, 1991. 

BID-32. Ambient Monitoring for PCB after Remedial Cleanup of Two Landfills in the 

Bloomington, Indiana Area, EPA/600/4-86/018, U.S. Environmental Protection Agency, 

Environmental Monitoring Systems Laboratory, Research Triangle Park, NC, March 1986. 

36
 
BID-33. Barboza M.J., P.E., An Integrated Study of Air Toxics Emissions from an MSW 

Landfill, Presented at the National Conference on Environmental Engineering, Paulus, 

Sokolowski and Sartor, Inc., Reno, NV, July 8-10, 1991. 

BID-34. Study of Vinyl Chloride Formation at Landfill Sites in California, Battelle Pacific 

Northwest labs, Prepared for California State Air Resources Board, Sacramento, CA, January 

1987. 

BID-35. In-Situ Methods to Control Emissions from Surface Impoundments and Landfills, 

EPA/600/2-85/124, U.S. Environmental Protection Agency, Hazardous Waste Engineering 

Research Laboratory, Cincinnati, OH, October 1985. 

BID-36. Trace-Chemical Characterization of Pollutants Occurring in the Production of Landfill 

Gas from the Shoreline Regional Park Sanitary Landfill, Mountain View, California, U.S. 

Department of Energy and Pacific Gas and Electric Company, April 1, 1981, DOE/CS/20291-­

T1. 

BID-37. Leachate Collection and Gas Migration and Emission Problems at Landfills and Surface 

Impoundments, EPA/600/2-86/017, U.S. Environmental Protection Agency, Office of Research 

and Development Cincinnati, OH, January 1986. 

BID-38. D. Antignano, Energy Tactics Inc., to J.R. Farmer, OAQPS:ESD, November 25, 1987, 

Response to questionnaire. 

BID-39. G. Rodriguez, Pacific Lighting Energy Systems, to J.R. Farmer, OAQPS:ESD, 

December 1, 1987, Response to questionnaire. 

BID-40. R. W. Van Bladeren, BioGas Technology, Inc., to J.R. Farmer, OAQPS:ESD, 

December 2, 1987, Response to questionnaire. 

BID-41. M. Nourot, Laidlaw Gas Recovery Systems, to J.R. Farmer, OAQPS:ESD, December 8, 

1987, Response to questionnaire. 

BID-42. K.A. Flanagan, GSF Energy Inc., to S.A. Thorneloe, OAQPS:EPA:CPB, January 27, 

1988, Response to questionnaire. 

BID-43. D.A. Stringham and W.H. Wolfe, Waste Management of North America, Inc., to J.R. 

Farmer, OAQPS:ESD, January 29, 1988, Response to Section 114 questionnaire. 

BID-44. D.L. Kolar, Browning-Ferris Industries, to J.R. Farmer, OAQPS:ESD, February 4, 

1988, Response to questionnaire. 

BID-45. Air Emissions from Municipal Solid Waste Landfills - Background Information for 

Proposed Standards and Guidelines, EPA-450/3-90-011a, U.S. Environmental Protection Agency, 

Office of Air Quality Planning and Standards, Research Triangle Park, NC, March 1991. 

BID-46. Pelt, R., Memorandum "Methodology Used to Revise the Model Inputs in the Solid 

Waste Landfills Input Data Bases (Revised)", to the Municipal Solid Waste Landfills Docket No. 

A-88-09, April 28, 1993. 

BID-47. Landfill Gas Production Curves, Myth Versus Reality, S.W. Zison, Pacific Energy. 

37
 
BID-48. Source Test Report 87-0318, Calabasas Landfill, December 16, 1987, South Coast Air 

Quality Management District. 

BID-49. Source Test Report 87-0329, Scholl Canyon Landfill, December 4, 1987, South Coast 

Air Quality Management District. 

BID-50. Source Test Report 87-0391, Puente Hills Landfill, February 5, 1988, South Coast Air 

Quality Management District. 

BID-51. Source Test Report 87-0376, Palos Verdes Landfill, February 9, 1987, South Coast Air 

Quality Management District. 

BID-52. Augenstein, D. and J. Pacey, Modeling Landfill Methane Generation, EMCON 

Associates, San Jose, CA, 1992. 

BID-53. Landfill Gas Characterization, Correspondence between C. Choate and J. Swanson, 

Waste Management of North America, Inc, Permit Services Division, Bay Area Quality 

Management District, Oakland, CA, 1988. 

BID-54. Emission Testing at BFI's Arbor Hills Landfill, Northville, Michigan, September 22 

through 25, 1992, Steiner Environmental, Inc., Bakersfield, CA, December 1992. 

BID-55. Emission Test Report - Performance Evaluation Landfill-Gas Enclosed Flare, Browning 

Ferris Industries, PEI Associates, Inc., Chicopee, MA, 1990. 

BID-56. Source Test Report Boiler and Flare Systems, Prepared for Laidlaw Gas Recovery 

Systems, Coyote Canyon Landfill, Irvine, CA, by Kleinfelder Inc., Diamond Bar, CA, 1991. 

BID-57. McGill Flare Destruction Efficiency Test Report for Landfill Gas at the Durham Road 

Landfill, Waste Management of North America, Inc, Bay Area Quality Management District, 

Oakland, CA, 1988. 

BID-58. Solid Waste Assessment for Otay Valley/Annex Landfill, Correspondence between R. 

Yelenosky and B. McEntire., San Diego Air Pollution Control District, San Diego, CA, 

December 1988. 

BID-59. Emission Test Report - Performance Evaluation Landfill Gas Enclosed Flare, Disposal 

Specialists Inc., PEI Associates, Inc., Rockingham, VT, September 1990. 

BID-60. Gas Flare Emissions Source Test for Sunshine Canyon Landfill, Browning Ferris 

Industries, Sylmar, CA, 1991. 

BID-61. Methane and Nonmethane Organic Destruction Efficiency Tests of an Enclosed Landfill 

Gas Flare, Scott Environmental Technology, April 1992. 

BID-62. Air Pollution Emission Evaluation Report for Ground Flare at Browning Ferris 

Industries Greentree Landfill, Kersey, Pennsylvania, BCM Engineers, Planners, Scientists and 

Laboratory Services, Pittsburgh, PA, May 1992. 

38
 
BID-63. Stack Emissions Test Report for Ameron Kapaa Quarry, EnvironMETeo Services Inc., 

Correspondence between C. How and F. Enos., Waipahu, HI, January 1994. 

BID-64. Report of Emission Levels and Fuel Economies for Eight Waukesha 12V-AT25GL 

Units Located at the Johnston, Rhode Island Central Landfill, Waukesha Pearce Industries, Inc. 

Houston TX, July 19, 1991. 

BID-65. Gaseous Emission Study Performed for Waste Management of North America, Inc., 

CID Environmental Complex Gas Recovery Facility, August 8, 1989, Mostardi-Platt Associates, 

Inc., Chicago, IL, August 1989. 

BID-66. Gaseous Emission Study Performed for Waste Management of North America, Inc., at 

the CID Environmental Complex Gas Recovery Facility, July 12-14, 1989, Mostardi-Platt 

Associates, Inc., Chicago, IL, July 1989. 

BID-67. Final Report for Emissions Compliance Testing of One Waukesha Engine Generator, 

Browning-Ferris Gas Services, Inc., Chicopee, MA, February 1994. 

BID-68. Final Report for Emissions Compliance Testing of Three Waukesha Engine Generators, 

Browning-Ferris Gas Services, Inc., Richmond, VA, February 1994. 

BID-69. Emission Factors for Landfill Gas Flares at the Arizona Street Landfill, Correspondence 

between D. Byrnes, A. dela Cruz, and M.R. Lake, Prepared by South Coast Environmental 

Company (SCEC) for the San Diego Air Pollution Control District, San Diego, CA, November 

1992. 

BID-70. Emission Tests on the Puente Hills Energy from Landfill Gas (PERG) Facility - Unit 

400, September 1993, Prepared for County Sanitation Districts of Los Angeles County by Carnot, 

Tustin, CA, November 1993. 

BID-71. Gaseous Emission Studies Performed for Waste Management of North America, Inc., at 

the CID Facility Centaur Turbine Stack 3, Chicago, Illinois, February 16, 1990, Mostardi-Platt 

Associates, Inc., Bensenville, IL, February 1990. 

BID-72. Gaseous Emission Study Performed for Waste Management of North America, Inc., at 

the Tazewell County Landfill, Peoria, Illinois, No. 1 Gas Recovery Engine Stack, February 22­

23, 1990, Mostardi-Platt Associates, Inc., Bensenville, IL, February 1990. 

BID-73. Gaseous Emission Study Performed for Waste Management of North America, Inc., at 

the Monroe Livingston Power Production Plant, Scottsville, New York, No. 2 Gas Recovery 

Engine Stack, May 2, 1990, Mostardi-Platt Associates, Inc., Bensenville, IL, May 1990. 

BID-74. Emissions Test Report for the Tripoli Landfill. Correspondence between J. Tice, Diesel 

and Gas Engineering Company, and S. Drake, Beaver Dams, NY, April 1989. 

BID-75. Compliance Test Report Landfill Gas Fired Internal Combustion Engine, Oceanside 

Landfill Gas Recovery Facility, Energy Tactics, Inc., Oceanside, NY, November 2, 1992. 

BID-76. Compliance Test Report Landfill Gas Fired Internal Combustion Engine, Dunbarton 

Road Landfill, Manchester, New Hampshire, ROJAC Environmental Services, Inc., Hartford, CT, 

June 1990. 

39
 
BID-77. Summary of Source Test Results for Palo Alto Emission Inventory Test, Bay Area Air 

Quality Management District, San Francisco, CA, June 1993. 

BID-78. Final Test Report for: Northeast Landfill Power-Joint Venture Engine No. 5 at the 

Rhode Island Central Landfill, Johnston, Rhode Island, Environmental Science Services, 

Providence, RI, May 1994. 

BID-79. Report of Emission Levels and Fuel Economies for Eight Waukesha 12V-AT25GL 

Units Located at the Johnston, Rhode Island Central Landfill, Waukesha Pearce Industries, Inc., 

Houston TX, November 30, 1990. 

BID-80. Landfill Gas Fired Flare Emission Factors for the Bonsall Location, Correspondence 

between M. Lake, and D. Byrnes. South Coast Air Quality Management District, CA, April 1994. 

BID-81. Landfill Gas Fired Flare Emission Factors for the Hillsborough Location, 

Correspondence between M. Lake, and D. Byrnes, South Coast Air Quality Management District, 

CA, April 1994. 

BID-82. Emission Factors for Landfill Gas Flares at the Bell Jr. High School Landfill, 

Correspondence between D. Byrnes, A. dela Cruz, and M.R. Lake, Prepared by South Coast 

Environmental Company (SCEC) for the San Diego Air Pollution Control District, San Diego, 

CA, November 1992. 

BID-83. Source Test Results for Emission Testing of Landfill Energy Partners Engine No. 1 at 

San Marcos Landfill, Carnot, Tustin, CA, October 1993. 

BID-84. Emission Factors for the Landfill Gas Fired Internal Combustion Engine at Otay 

Landfill, Operated by Pacific Energy, Correspondence between D. Byrnes and L. Kramer, San 

Diego County Air Pollution Control District, San Diego, CA, October 1991. 

BID-85. Testing of Monitored Pollutants in Exhaust Gases at the San Marcos Landfill, San 

Diego Air Pollution Control District, San Diego, CA, October 1989. 

BID-86. Staff Report, Proposed Amended Rule 431.1, Sulfur Content of Gaseous Fuels, South 

Coast Air Quality Management District, Rule Development Division, El Monte, CA, April 1990. 

BID-87. Engineering Report: Puente Hills Landfill, Flare #11, Dioxin, Furan, and PCB Test 

Results, Sierra Environmental Engineering Inc., Costa Mesa, CA, February 1986. 

BID-88. Compliance Testing for Spadra Landfill Gas-to-Energy Plant, July 25 and 26, 1990, 

Pape & Steiner Environmental Services. Bakersfield, CA, November 1990. 

BID-89. AB2588 Source Test Report for Oxnard Landfill, July 23-27, 1990, by Petro Chem 

Environmental Services, Inc., for Pacific Energy Systems, Commerce, CA, October 1990. 

BID-90. AB2588 Source Test Report for Oxnard Landfill, October 16, 1990, by Petro Chem 

Environmental Services, Inc., for Pacific Energy Systems, Commerce, CA, November 1990. 

BID-91. Engineering Source Test Report for Oxnard Landfill, December 20, 1990, by Petro 

Chem Environmental Services, Inc., for Pacific Energy Systems, Commerce, CA, January 1991. 

40
 
BID-92. AB2588 Emissions Inventory Report for the Salinas Crazy Horse Canyon Landfill, 

Pacific Energy, Commerce, CA, October 1990. 

BID-93. Newby Island Plant 2 Site IC Engine's Emission Test, February 7-8, 1990, Laidlaw Gas 

Recovery Systems, Newark, CA, February 1990. 

BID-94. Landfill Methane Recovery Part II: Gas Characterization, Final Report, Gas Research 

Institute, December 1982. 

BID-95. Letter from J.D. Thornton, Minnesota Pollution Control Agency, to R. Myers, U.S. 

EPA, February 1, 1996. 

BID-96. Letter and attached documents from M. Sauers, GSF Energy, to S. Thorneloe, U.S. 

EPA, May 29, 1996. 

BID-97. Landfill Gas Particulate and Metals Concentration and Flow Rate, Mountaingate 

Landfill Gas Recovery Plant, Horizon Air Measurement Services, prepared for GSF Energy, Inc., 

May 1992. 

BID-98. Landfill Gas Engine Exhaust Emissions Test Report in Support of Modification to 

Existing IC Engine Permit at Bakersfield Landfill Unit #1, Pacific Energy Services, December 4, 

1990. 

BID-99. Addendum to Source Test Report for Superior Engine #1 at Otay Landfill, Pacific 

Energy Services, April 2, 1991. 

BID-100. Source Test Report 88-0075 of Emissions from an Internal Combustion Engine Fueled 

by Landfill Gas, Penrose Landfill, Pacific Energy Lighting Systems, South Coast Air Quality 

Management District, February 24, 1988. 

BID-101. Source Test Report 88-0096 of Emissions from an Internal Combustion Engine Fueled 

by Landfill Gas, Toyon Canyon Landfill, Pacific Energy Lighting Systems, South Coast Air 

Quality Management, March 8, 1988. 

BID-102. Letter and attached documents from C. Nesbitt, Los Angeles County Sanitation 

Districts, to K. Brust, E.H. Pechan and Associates, Inc., December 6, 1996. 

BID-103. Determination of Landfill Gas Composition and Pollutant Emission Rates at Fresh 

Kills Landfill, revised Final Report, Radian Corporation, prepared for U.S. EPA, November 10, 

1995. 

BID-104. Advanced Technology Systems, Inc., Report on Determination of Enclosed Landfill 

Gas Flare Performance, Prepared for Y & S Maintenance, Inc., February 1995. 

BID-105. Chester Environmental, Report on Ground Flare Emissions Test Results, Prepared for 

Seneca Landfill, Inc., October 1993. 

BID-106. Smith Environmental Technologies Corporation, Compliance Emission Determination 

of the Enclosed Landfill Gas Flare and Leachate Treatment Process Vents, Prepared for Clinton 

County Solid Waste Authority, April 1996. 

41
 
 

 

BID-107. AirRecon7, Division of RECON Environmental Corp., Compliance Stack Test Report 

for the Landfill Gas FLare Inlet & Outlet at Bethlehem Landfill, Prepared for LFG Specialties 

Inc., December 3, 1996. 

BID-108. ROJAC Environmental Services, Inc., Compliance Test Report, Hartford Landfill 

Flare Emissions Test Program, November 19, 1993. 

BID-109. Normandeau Associates, Inc., Emissions Testing of a Landfill Gas Flare at Contra 

Costa Landfill, Antioch, California, March 22, 1994 and April 22, 1994, May 17, 1994. 

BID-110. AirRecon, Compliance Stack Emission Evaluation, Gloucester County Solid Waste 

Complex, May 14, 1996. 

U.S. Environmental Protection Agency (1997b). Emission Factor Documentation for AP-42 

Section 2.4 – Municipal Solid Waste Landfills, Revised, Office of Air Quality Planning and 

Standards. Research Triangle Park, NC, August 1997. 

U.S. Environmental Protection Agency (1998). Compilation of Air Pollutant Emission Factors, 

AP-42, Fifth Edition, Volume I: Stationary Point and Area Sources, Section 2.4 Municipal Solid 

Waste Landfills, Research Triangle Park, NC, November 1998. 

42
 
3.0 CONTROLLED LANDFILL GAS DATA ANALYSIS RESULTS 

Emission factors for control devices apply to landfills with waste in place both before and after 

1992. Development of emission factors for each combustion control device type is discussed in the 

following sections. 

3.1 FLARES 

Landfill gas flare combustion by-product emissions data for a total of 35 landfills were submitted 

to EPA and utilized in emission factor development, comprising a total of 53flares contained in 41 test 

reports. Six of the test reports contained test data from two different landfills but represent six different 

flares (TR-181, TR-182, and TR-205 for one landfill, and TR-259, TR-260, and TR- 261 for another 

landfill). The manufacturer was specified for 23 of the flares (Table 3-1). These flares are assumed to be 

enclosed since sampling candle-stick flares is not typically done. Enclosed flares are designed to allow 

for performance testing to establish emission reduction capability and potential by-product emissions. 

TABLE 3-1. SUMMARY OF NUMBER OF FLARES AND MANUFACTURERS FOR
 

LANDFILL GAS FLARE COMBUSTION BY-PRODUCT EMISSIONS TEST DATA
 

Flare Manufacturer Number of Emission 

Test Reports 

Callidus 1 

John Zink 14 

LFG Specialties 1 

McGill 2 

Perennial Energy 3 

SurLite 2 

Not Specified 30 

Total 53 

Nitrogen oxides, carbon monoxide, and particulate matter emissions were sampled and reported 

in units of parts per million (ppm), pounds per hour (lb/hr), or pounds per day (lb/day). Total 

dioxin/furan emissions were reported in nanograms per dry standard cubic meter (ng/dscm). Twenty-five 

test reports contained emissions data for NOX, CO, and PM. One test report contained data for NOX, CO, 

and total dioxins/furans. Five test reports contained emissions data for both NOX and CO, one test report 

contained only NOX emission data, and five test reports contained only CO emissions data. Where 

possible, each of the emission data points were converted to kilograms per million dry standard cubic 

meters of CH4 (kg/106 dscm CH4) to result in comparable emissions for a variety of LFG flares (See 

Appendix G for sample calculation). 

3.1.1 Nitrogen Oxides 

The default NOx emission factor was calculated from 36 test reports containing NOX emissions 

data from a total of 48 flares. 

The emission rate provided in TR-148 was excluded from the NOX analysis because the flare inlet 

gas flow rate was reported in standard cubic feet per minute (scfm) and inlet gas moisture was not 

determined as part of the flare testing. Consequently, a NOX emission factor could not be developed on 

the basis of dry standard cubic meters of inlet CH4 for TR-148. The emission rate provided for TR-160 

43
 
was excluded from the NOX analysis because flare inlet gas composition data was not provided in the test 

report. As a result, an emission factor could not be calculated for TR-160. 

One test report (TR-241) revealed NOx emission rates below the method detection limit (<0.59 

kg/hr or 392 kg/106

 dscm CH4) for all test runs. Based on guidance for detection limits contained in 

EPA’s Procedures for Preparing Emission Factor Documents (U.S. EPA, 1997a), half of the method 

detection limit was used to represent this flare’s average emission rate. Since there are detect values 

greater than this non-detect, the value is used in emission factor determination calculations 

Two of the 36 test reports (TR-145 and TR-146) contained NOX test data obtained from operating 

the flare under two different operating temperatures. For both cases, the data associated with the set of 

test runs that most closely matched the average testing temperature from the other 34 test reports (1,552 

oF) was used for the development of the default NOX emission factor. 

Emission rates for the 46 flares (excluding the two flares from TR-148 and TR-160) included in 

the analysis range from 211 to 1,373 kg/106

 dscm CH4. The arithmetic mean emission rate for NOX for 

these LFG flares is 631 kg/106

 dscm CH4. This average rate was selected as the default emission factor to 

represent flare NOX in the AP-42 update with an A quality rating. The previous AP-42 default factor 

(U.S. EPA, 1998) was 650 kg/106

 dscm CH4 with a quality rating of “C.” 

3.1.2 Carbon Monoxide 

The CO default emission factor was calculated from 40 test reports containing emissions data 

from 52 flares. 

The emission rate provided in TR-148 was excluded from the CO analysis because the flare inlet 

gas flow rate was reported in standard cubic feet per minute (scfm) and inlet gas moisture was not 

determined as part of the flare testing. Consequently, a CO emission factor could not be developed on the 

basis of dry standard cubic meters of inlet CH4 for TR-148. The emission rate provided for TR-160 was 

excluded from the CO analysis because flare inlet gas composition data was not provided in the test 

report. As a result, an emission factor could not be calculated for TR-160. 

Four test reports (TR-157, TR-175, TR-179, and TR-251) revealed CO emission rates below the 

method detection limits. Based on guidance for detection limits contained in EPA’s Procedures for 

Preparing Emission Factor Documents (U.S. EPA, 1997a), half of the method detection limits were used 

to represent the average emission rate. Since there are detect values greater than the non-detect values, 

the values are used in emission factor determination calculations 

Two of the 40 test reports (TR-145 and TR-146) contained CO test data obtained from operating 

the each flare under two different operating temperatures. For both cases, the data associated with the set 

of test runs that most closely matched the average testing temperature from the other 36 test reports 

(1,551 oF) was used for the development of the default CO emission factor. 

Carbon monoxide emission rates for the 50 flares (excluding the two flares from TR-148 and TR160) included in the analysis range from 0 to 11,500 kg/106

 dscm CH4. The arithmetic mean emission 

rate for CO is 737 kg/106

 dscm CH4, which was selected as the default emission factor with an A quality 

rating for the AP-42 update. The prior default factor in AP-42 (U.S. EPA, 1998) was 12,000 kg/106

 dscm 

CH4 with a quality rating of “C.” It is worth noting that the new default emission factor is based on over 

three times the amount of data as the previous emission factor, which may help explain the large 

difference between the default values. 

44
 
 

3.1.3 Particulate Matter 

The default PM emission factor was calculated from 28 test reports containing emissions data 

from 36 flares. 

One of the test reports (TR-146) contained PM test data obtained from operating the flare under 

two different operating temperatures. The data associated with the set of test runs that most closely 

matched the average testing temperature from the other test reports (1,548 oF) was used for the 

development of the default CO emission factor. 

The emission rate provided in TR-148 was excluded from the PM analysis because the flare inlet 

gas flow rate was reported in standard cubic feet per minute (scfm) and inlet gas moisture was not 

determined as part of the flare testing. Consequently, a PM emission factor could not be developed on the 

basis of dry standard cubic meters of inlet CH4. 

The PM emission rates from the 35 flares (excluding the flare from TR-148) included in the 

analysis range between 84 and 735 kg/106

 dscm CH4. The arithmetic mean emission rate for PM is 238 

kg/106

 dscm CH4 with an A quality rating. This average rate was selected as the default to represent PM 

in the AP-42 update. The prior version of the AP-42 section for MSW landfills (U.S. EPA, 1998) had a 

default PM emission factor of 270 kg/106

 dscm CH4 with a quality rating of “D.” 

3.1.4 Total Dioxin/Furan 

One test report (TR-273) contained measurement data for dioxins/furans. The total dioxin/furan 

emission rate is 6.7 x 10-6 kg/106

 dscm CH4, which was selected as the default emission factor for the AP42 update. The previous AP-42 section for MSW landfills (U.S. EPA, 1998) did not include dioxin/furan 

emission factors for LFG flares. 

3.1.5 Flare Summary 

Summaries of the NOX, CO, PM, and total dioxin/furan combustion by-product data included in 

the LFG flare analysis for determining default emission factors for the update can be found in Tables 3-4, 

3-5, and 3-6. In addition, the three tables provide the test methods used to measure these emissions data. 

A data quality rating of A was assigned to each of the flare test reports listed in Tables 3-4, 3-5, 

and 3-6. All of the reports containing these data included adequate detail, the methodology appeared to 

be sound, and no problems were reported for the test runs. The following criteria, used in developing 

ratings in the 1998 AP-42 update, were used to provide recommended default emission factor ratings. 

TABLE 3-2. CRITERIA USED TO DETERMINE RECOMMENDED DEFAULT 

EMISSION FACTOR RATINGS 

Factor Rating # of Data Points 

A ≥ 20 

B 10-19 

C 6-9 

D 3-5 

E <3 

An overall data quality rating of A is recommended for the NOX, CO, and PM combustion byproducts from flares default emission factors. This rating exemplifies the fact that the default NOX, CO, 

and PM emission factors were developed using A-rated test data and the emission factor ranking is more 

45 
of a function of the number of data points used to develop the default emission factor. Furthermore, no 

specific bias is evident for the NOX, CO, and PM emission factors. An overall data quality rating of E is 

recommended for the total dioxin/furan combustion by-product default emission factor since the emission 

factor was developed from a single facility which does not represent a random sample of LFG flares 

(Table 3-3). 

TABLE 3-3. RECOMMENDED DEFAULT EMISSION FACTOR RATINGS FOR NOX, CO, 

PM, AND TOTAL DIOXIN/FURAN LANDFILL FLARE COMBUSTION BY-PRODUCTS 

Flare Combustion 

By-Product # of Data Points Recommended Emission Factor Rating 

NOx 30 A 

CO 34 A 

PM 23 A 

Total Dioxin/Furan 1 E 

TABLE 3-4. LANDFILL GAS FLARE NOx EMISSIONS DATA USED TO DEVELOP
 

COMBUSTION BY-PRODUCT EMISSION FACTORS 

Test Report Test Method Flare Combustion 

By-Product 

Calculated Emission Factor 

(kg/106

 dscm CH4) 

TR-145a EPA Method 7E NOx 671 

TR-146a EPA Method 7E NOx 1,200 

TR-159 EPA Method 7E NOx 634 

TR-165 SCAQMD Method 100.1 NOx 669 

TR-168 SCAQMD Method 100.1 NOx 341 

TR-169 SCAQMD Method 100.1 NOx 322 

TR-171 SCAQMD Method 100.1 NOx 608 

TR-173 SCAQMD Method 100.1 NOx 563 

TR-175b SCAQMD Method 100.1 NOx 725 

TR-176 SCAQMD Method 100.1 NOx 656 

TR-178 SCAQMD Method 100.1 NOx 458 

TR-179 SCAQMD Method 100.1 NOx 502 

TR-181, TR-182, TR-205c SCAQMD Method 100.1 NOx 320 

TR-183 SCAQMD Method 100.1 NOx 520 

TR-187 SCAQMD Method 100.1 NOx 430 

TR-196 CARB Method 100/EPA Method 7E NOx 677 

TR-199 SCAQMD Method 100.1 NOx 449 

TR-207 SCAQMD Method 100.1 NOx 1,370 

TR-209d EPA Method 7E NOx 1,080 

TR-229 SCAQMD Method 100.1 NOx 823 

TR-241e EPA Method 7A NOx 392 

46
 
 

TABLE 3-4 (CONTINUED). LANDFILL GAS FLARE NOX EMISSIONS DATA USED TO DEVELOP
 

COMBUSTION BY-PRODUCT EMISSION FACTORS
 

Test Report Test Method Flare Combustion 

By-Product 

Calculated Emission Factor 

(kg/106

 dscm CH4) 

TR-251 SCAQMD Method 100.1 NOx 848 

TR-253 SCAQMD Method 100.1 NOx 846 

TR-255 SCAQMD Method 100.1 NOx 543 

TR-258 CARB Method 100 NOx 554 

TR-259, TR-260, TR-261c SCAQMD Method 100.1 NOx 234 

TR-264 SCAQMD Method 100.1 NOx 939 

TR-273 EPA Method 7E NOx 741 

TR-287 EPA Method 7E NOx 596 

TR-290 SCAQMD Method 100.1 NOx 211 

NOx Default Emission Factor 631 

1998 AP-42 NOx Emission Factorf

 650 a

 Average flare temperature for tests where the temperature was not varied is 1552oF. For tests performed under multiple
 

temperatures, the test where the operating temperature was closest to the average was included. See discussion for additional 

details. 

b

 Emission factor calculated is based on the average emissions for three flares. 

c

 Three test reports for three separate flares at the same landfill.
 d

 Emission factor calculated is based on the average emissions for five flares. 

e

 Based on guidance in EPA's Procedures for Preparing Emission Factor Documents for detection limits, half of the method 

detection limit was used to represent this landfill's average emission rate. Since there are detect values greater than this nondetect, the value is used in emission factor determination calculations. 

f

 AP-42, Fifth Edition, Volume I, Section 2.4, Supplement E, November 1998.
 

TABLE 3-5. LANDFILL GAS FLARE CO EMISSIONS DATA USED TO DEVELOP 

COMBUSTION BY-PRODUCT EMISSION FACTORS 

Test Report Test Method Flare Combustion ByProduct 

Calculated Emission 

Factor 

(kg/106

 dscm CH4) 

TR-145a EPA Method 10, 40 CFR 60, Appendix A CO 533 

TR-146a EPA Method 10, 40 CFR 60, Appendix A CO 23 

TR-147 EPA Method 10, 40 CFR 60, Appendix A CO 13 

TR-153 EPA Method 10, 40 CFR 60, Appendix A CO 105 

TR-156 EPA Method 10, 40 CFR 60, Appendix A CO 53 

TR-157b EPA Method 10, 40 CFR 60, Appendix A CO 12 

TR-159 EPA Method 10, 40 CFR 60, Appendix A CO 911 

TR-165 SCAQMD Method 100 CO 1,550 

TR-168 SCAQMD Method 100 CO 11 

TR-169 SCAQMD Method 100.1 CO 15 

TR-171 SCAQMD Method 100.1 CO 319 

TR-173 SCAQMD Method 100.1 CO 263 

47
 
 

TABLE 3-5 (CONTINUED). LANDFILL GAS FLARE CO EMISSIONS DATA USED TO 

DEVELOP COMBUSTION BY-PRODUCT EMISSION FACTORS 

Test Report Test Method Flare Combustion ByProduct 

Calculated Emission 

Factor 

(kg/106

 dscm CH4) 

TR-175b,d SCAQMD Method 100.1/SCAQMD 

Method 10.1 TCA/FID CO 29 

TR-176 SCAQMD Method 100.1 CO 13 

TR-178 SCAQMD Method 100.1 CO 276 

TR-179b SCAQMD Method 100.1 CO 262 

TR-181, TR-182, TR-205e SCAQMD Method 100.1 CO 164 

TR-183 SCAQMD Method 100.1 CO 541 

TR-187 SCAQMD Method 100.1 CO 76 

TR-196 CARB Method 100/EPA Method 10 CO 2,010 

TR-199 SCAQMD Method 100.1 CO 11,500 

TR-207 SCAQMD Method 100.1 CO 639 

TR-209c EPA Method 10, 40 CFR 60, Appendix A CO 100 

TR-226 EPA Method 10, 40 CFR 60, Appendix A CO 67 

TR-229 SCAQMD Method 100.1 CO 28 

TR-251b SCAQMD Method 25.1 CO 306 

TR-253 SCAQMD Method 100.1 CO 13 

TR-255 SCAQMD Method 100.1 CO 434 

TR-258 CARB Method 100 CO 23 

TR-259, TR-260, TR-261e SCAQMD Method 100.1 CO 175 

TR-264 SCAQMD Method 100.1 CO 780 

TR-273 EPA Method 10, 40 CFR 60, Appendix A CO 410 

TR-287 EPA Method 10, 40 CFR 60, Appendix A CO 3,420 

TR-290 SCAQMD Method 100.1 CO 0 

 CO Default Emission Factor 737 

1998 AP-42 CO Emission Factorf

 12,000 

a

 Average flare temperature for tests where the temperature was not varied is 1551oF. For tests performed under multiple
 

temperatures, the test where the operating temperature was closest to the average was included. See discussion for additional 

details. 

b

 Based on guidance in EPA's Procedures for Preparing Emission Factor Documents for detection limits, half of the method 

detection limit was used to represent this landfill's average emission rate. Since there are detect values greater than this nondetect, the value is used in emission factor determination calculations. 

c

 Emission factor calculated is based on the average emissions for five flares. 

d

 Emission factor calculated is based on the average emissions for three flares. 

e

 Three test reports for three separate flares at the same landfill.
 f

 AP-42, Fifth Edition, Volume I, Section 2.4, Supplement E, November 1998. 

48
 
 

TABLE 3-6. LANDFILL GAS FLARE PM AND TOTAL DIOXIN/FURAN EMISSIONS DATA 

USED TO DEVELOP COMBUSTION BY-PRODUCT EMISSION FACTORS 

Test Report Test Method Flare Combustion ByProduct 

Calculated Emission Factor 

(kg/106

 dscm CH4) 

TR-145 EPA Method 0050 PM 142 

TR-146a EPA Method 0050 PM 226 

TR-165 SCAQMD Method 5.2 PM 187 

TR-168 SCAQMD Method 5.1 PM 309 

TR-171 SCAQMD Method 5.1 PM 735 

TR-173 SCAQMD Method 5.1 PM 256 

TR-175b SCAQMD Method 5.1 PM 143 

TR-176 SCAQMD Method 5.1 PM 165 

TR-178 SCAQMD Method 5.1 PM 531 

TR-179 SCAQMD Method 5.1 PM 251 

TR-181, TR-182, TR-205c SCAQMD Method 5.1 PM 84 

TR-183 SCAQMD Method 5.1 PM 193 

TR-187 SCAQMD Method 5.1 PM 249 

TR-196 SCAQMD Method 5.1 PM 401 

TR-199 SCAQMD Method 5.1 PM 184 

TR-207 SCAQMD Method 5.2 PM 130 

TR-229 SCAQMD Method 5.1 PM 313 

TR-251 SCAQMD Method 5.1 PM 277 

TR-253 SCAQMD Method 5.1 PM 131 

TR-255 SCAQMD Method 5.1 PM 138 

TR-259, TR-260, TR-261c SCAQMD Method 5.1 PM 97 

TR-264 SCAQMD Method 5.1 PM 205 

TR-290 SCAQMD Method 5.1 PM 133 

 PM Default Emission Factor 238 

1998 AP-42 PM Emission Factord

 270 

TR-273 EPA Method 23 Dioxin/Furan 6.7E-06 

 Dioxin/Furan Default Emission Factore

 6.76E-06 a

 Average flare temperature for tests where the temperature was not varied is 1548oF. For tests performed under multiple
 

temperatures, the test where the operating temperature was closest to the average was included. See discussion for additional 

details. 

b

 Emission factor calculated is based on the average emissions for three flares. 

c

 Three test reports for three separate flares at the same landfill.
 d

 AP-42, Fifth Edition, Volume I, Section 2.4, Supplement E, November 1998. e

 New default emission factor. No emission factor for dioxin/furan is in the latest AP-42 update. 

49
 
 

References 

TR-145. Compliance Testing of a Landfill Flare at Browning-Ferris Gas Services, Inc.'s Facility 

in Halifax, Massachusetts, BFI Waste Systems of North America, Inc., May 1996. 

TR-146. Compliance Source Testing of a Landfill Flare at Northern Disposal, Inc. East 

Bridgewater Landfill, Northern Disposal, Inc., June 1994. 

TR-147. Compliance Emissions Test Program for BFI of Ohio, Inc., BFI of Ohio, Inc., 6/26/98.
 

TR-148. Compliance Testing of Landfill Flare at Browning-Ferris Gas Services, Inc.'s Fall River 

Landfill Flare, BFI Waste Systems of North America, Inc., March 1995. 

TR-153. Results of the Emission Compliance Test on the Enclosed Flare System at the Carbon 

Limestone Landfill, Browning-Ferris Industrial Gas Services, Inc., 8/8/96. 

TR-156. Results of the Emission Compliance Test on the Enclosed Flare System at the Lorain 

County Landfill No. 2, Browning-Ferris Industrial Gas Services, Inc., 9/5/96. 

TR-157. Emission Compliance Testing Browning-Ferris Gas Services, Inc. Willowcreek Landfill, 

BFI-Willowcreek, 2/2/98. 

TR-159. Compliance Stack Sampling Report, Monmouth County Reclamation Center, SCS 

Engineers (Reston, VA), 9/8/95. 

TR-160. Source Emission Testing of an Enclosed Landfill Gas Ground Flare, SCS Engineers 

(Reston, VA), September 1997. 

TR-165. 1997 Annual Compliance Source Testing Results for the Coyote Canyon Landfill Gas 

Recovery Facility Flare No. 1, Laidlaw Gas Recovery Systems, January 1998. 

TR-168. Colton Sanitary Landfill Gas Flare No. 2 (John Zink) 1998 Source Tests Results, Bryan 

A. Stirrat & Associates, 9/29/98. 

TR-169. Colton Sanitary Landfill Gas Flare No. 1 (McGill) 1998 Source Tests Results, Bryan A. 

Stirrat & Associates, 9/29/98. 

TR-171. High Landfill Gas Flow Rate Source Test Results from One Landfill Gas Flare at FRB 

Landfill in Orange County, California, Bryan A. Stirrat & Associates, July 1997. 

TR-173. Annual Emissions Test of Landfill Gas Flare #3 Bradley Landfill, Waste Management 

Recycling and Disposal Services of California, Inc., 4/12/99. 

TR-175. Emissions Tests on Flares #2, #4 and #6 at the Lopez Canyon Landfill, City of Los 

Angeles, August 1997. 

TR-176. Emissions Test Results on Flares #1, #4 and #9 Calabasas Landfill, County Sanitation 

Districts of Los Angeles County, February 1998. 

TR-178. Annual Emission Test of Landfill Gas Flare #3 Bradley Landfill, Waste Management 

Recycling and Disposal Services of California, Inc., 5/21/98. 

50
 
 

TR-179. Annual Emissions Test of Landfill Gas Flare #1 Bradley Landfill, Waste Management 

Recycling and Disposal Services of California, Inc., 4/13/99. 

TR-181. The Mid-Valley Sanitary Landfill Gas Flare No.1 (McGill) 1998 Source Test Results, 

Bryan A. Stirrat & Associates, 9/29/98. 

TR-182. The Mid-Valley Sanitary Landfill Gas Flare No.2 (SurLite) 1998 Source Test Results, 

Bryan A. Stirrat & Associates, 9/29/98. 

TR-183. Annual Emissions Test of Landfill Gas Flare #2 Bradley Landfill, Waste Management 

Recycling and Disposal Services of California, Inc., 4/13/99. 

TR-187. Emissions Test of a Landfill Gas Flare - Lowry Landfill/Denver-Arapohoe Disposal 

Site, Sur-Lite Corporation, February 1997. 

TR-196. Results of the Biennial Criteria and AB 2588 Air Toxics Source Test on the Simi Valley
 

Landfill Flare, Simi Valley Landfill and Recycling Center, April 1997. 

TR-199. Emission Compliance Test on a Landfill Flare, City of Los Angeles, January 1999. 

TR-205. The Mid-Valley Sanitary Landfill Gas Flare No. 3 (John Zink) 1998 Source Test 

Results, Bryan A. Stirrat & Associates, 9/29/98. 

TR-207. Compliance Source Test Report Landfill Gas-fired Flare Stations I-4 and F-2, BKK 

Landfill, 12/12/97. 

TR-209. Emission Test Report Volumes I and II - Source/Compliance Emissions Testing for 

Cedar Hills Landfill, King County Solid Waste Division, 1/20/05. 

TR-226. Methane and Nonmethane Organic Destruction Efficiency Tests of an Enclosed Landfill 

Gas Flare, Newco Waste Systems, April 1992. 

TR-229. Scholl Canyon Landfill Gas Flares No. 9, 10 11 and 12 Emission Source Testing April 

1999, South Coast Air Quality Management District, April 1999. 

TR-241. Performance Evaluation, Enclosed Landfill Gas Flare, Valley Landfill, Waste Energy
 

Technology, November 1991. 

TR-251. Emission Compliance Test on a Landfill Gas Flare - Flare #1, Frank R. Bowerman 

Landfill, Orange County, 1/25/99. 

TR-253. Emission Source Testing on Two Flares (Nos. 3 and 6) at the Spadra Landfill, Los 

Angeles County Sanitation Districts, 7/21/98. 

TR-255. Emission Compliance Test on a Landfill Gas Flare -Olinda Alpha Landfill, Orange 

County Integrated Waste Management Department, No Report Date Given. 

TR-258. Source Test Report, City of Sacramento Landfill Gas Flare, City of Sacramento, 6/26/96. 

51
 
 

TR-259. The Millikan Sanitary Landfill Gas Flare No. 1 (Surlite) 1998 Source Test Results, 

South Coast Air Quality Management District, 9/29/98. 

TR-260. The Millikan Sanitary Landfill Gas Flare No. 2 (John Zink) 1998 Source Test Results, 

South Coast Air Quality Management District, 9/29/98. 

TR-261. The Millikan Sanitary Landfill Gas Flare No. 3 (John Zink) 1998 Source Test Results, 

South Coast Air Quality Management District, 9/29/98. 

TR-264. Emission Compliance Test on a Landfill Gas Flare, Orange County Integrated Waste 

Management Department, No Report Date Given. 

TR-273. Source Testing Final Report - Landfill B, US EPA Air Pollution Prevention and Control 

Division, 10/6/05. 

TR-287. Source Testing Final Report - Landfill D, US EPA Air Pollution Prevention and Control 

Division, 10/6/05. 

TR-290. San Timoteo Sanitary Landfill 1998 Source Test Results, San Bernandino County Solid 

Waste Management, 9/29/98. 

U.S. Environmental Protection Agency (1997a). Procedures for Preparing Emission Factor 

Documents ,EPA-454/R-95-015, Office of Air Quality Planning and Standards, Research 

Triangle Park, NC, November 1997. 

U.S. Environmental Protection Agency (1998). Compilation of Air Pollutant Emission Factors, 

AP-42, Fifth Edition, Volume I: Stationary Point and Area Sources, Section 2.4 Municipal Solid 

Waste Landfills, Research Triangle Park, NC, November 1998. 

52
 
3.2 BOILERS, ENGINES AND TURBINES 

3.2.1 Boiler Combustion By-Product Emissions – Source Characterization, Test Methods and Results 

Combustion by-product emissions data for LFG-fired boilers were submitted to EPA for a total of 

seven landfills. However, one boiler test report (TR-163) was excluded from the analysis because the 

report provided to EPA is incomplete and does not contain any test method or sampling information. 

Nitrogen oxide and carbon monoxide emissions were sampled and reported in units of parts per million 

(ppm), pounds per hour (lb/hr), pounds per day (lb/day), or grams per cubic meter of CH4 (g/m3

 CH4) for 

six boilers. Four of the test reports also contain particulate matter emissions data, given in lb/hr, lb/day, 

or g/m3

 CH4. Five boiler test reports have total dioxin/furan emissions in nanograms per dry standard 

cubic meter (ng/dscm), picograms in toxicity equivalents (TEQ) per cubic meter (pg TEQ/m3

), or lb/hr. 

Where possible, each of the emission data points were converted to kilograms per million dry standard 

cubic meters of CH4 (kg/106

 dscm CH4) to result in comparable emissions for a variety of LFG-fired 

boilers. 

Of the six boiler test reports used in the analysis, three boilers (TR-167, TR-220, TR-291) are 

Zurn steam boilers. One of these boilers is equipped with dual Coen burners such that the LFG may be 

supplemented with natural gas in order to maintain acceptable Btu levels. One boiler (TR-292) is a 

Combustion Engineering Model 33-7KT-10, A-type package base-load steam boiler. The remaining two 

boilers did not specify the type of boiler tested. There were no “A” or “B” quality test reports available 

for boilers from the prior AP-42 update that could be utilized in this analysis. 

3.2.1.1 Nitrogen Oxides 

Five of the six test reports (TR-167, TR-188, TR-220, TR-268, TR-291, TR-292) containing NOX 

emissions data were included in the analysis to determine a default emission factor. The emission rate 

provided for TR-188 was excluded from the NOX analysis because samples were collected and analyzed 

using a portable combustion gas analyzer, which is not considered an acceptable test method for the AP42 analysis. 

The two lowest emission rates are represented by boilers (TR-167, TR-220) equipped with flue 

gas recirculation to reduce NOX formation, although the difference between these two rates and the next 

two highest rates is not a significant amount. 

Emission rates for the six boilers included in the analysis range from 563 to 1,040 kg/106

 dscm 

CH4. The arithmetic mean emission rate for NOX for these LFG-fired boilers is 677 kg/106

 dscm CH4. 

This average rate was selected as the default emission factor to represent boiler NOX in the AP-42 update 

with a D quality rating. The 1998 default factor in AP-42 (U.S. EPA, 1998) is 530 with a D quality 

rating. 

3.2.1.2 Carbon Monoxide 

Four of the six test reports (TR-167, TR-188, TR-220, TR-268, TR-291, TR-292) containing CO 

emissions data were included in the analysis to determine a default emission factor. The emission rate 

provided for TR-188 was excluded from the CO analysis because samples were collected and analyzed 

using a portable combustion gas analyzer, which is not considered an acceptable test method for the AP42 analysis. Another report (TR-291) reveals CO emission rates below the method detection limit (<0.03 

kg/hr or 16 kg/106

 dscm CH4) for all test runs. Based on guidance for detection limits contained in EPA’s 

Procedures for Preparing Emission Factor Documents (U.S. EPA, 1997a), half of the detection limit 

(0.014 kg/hr or 8 kg/106

 dscm CH4) should be used to represent the average CO emission rate. However, 

53
 
the halved rate is greater than the detect value for the CO emission rate for another test report (TR-220). 

Therefore, as directed in the EPA procedures document, this halved emission rate was not used to 

determine a default CO emission factor. 

Carbon monoxide emission rates range from 3 to 250 kg/106

 dscm CH4. The arithmetic mean 

emission rate for CO is 116 kg/106 dscm CH4, which was selected as the default emission factor with a 

“D” quality rating for the AP-42 update. The prior default factor in AP-42 (U.S. EPA, 1998) is 90 kg/106 

dscm CH4 with a quality rating of “E.” 

3.2.1.3 Particulate Matter 

Particulate matter emissions are provided in four boiler test reports (TR-167, TR-188, TR-220, 

TR-268). These four PM emission rates range between 10 and 71 kg/106

 dscm CH4. The arithmetic 

mean emission rate for PM is 41 kg/106

 dscm CH4. This average rate was selected as the default to 

represent PM in the AP-42 update, with a “D” quality rating. The previous AP-42 section for MSW 

landfills (U.S. EPA, 1998) has a default PM emission factor of 130 kg/106

 dscm CH4 with a quality rating 

of “D.” 

3.2.1.4 Total Dioxin/Furan 

Five test reports (TR-188, TR-220, TR-268, TR-291, TR-292) contain measurement data for 

dioxins/furans. Emissions data for one boiler test report (TR-188) were excluded from the dioxin/furan 

analysis because data were only reported on a TEQ basis but total dioxin/furan on a mass basis was being 

used in the analysis to determine a default emission factor. Three test reports (TR-220, TR-268, TR-291) 

reveal total dioxin/furan emission rates below the method detection limit for all test runs. Based on 

guidance for detection limits contained in EPA’s Procedures for Preparing Emission Factor Documents 

(U.S. EPA, 1997a), half of the detection limit was used to represent the average emission rate of total 

dioxin/furan for these boilers. 

Total dioxin/furan emission rates range from 1.4 x 10-6 to 1.5 x 10-5 kg/106

 dscm CH4. The 

arithmetic mean emission rate for total dioxin/furan is 5.1 x 10-6 kg/106

 dscm CH4, which was selected as 

the default emission factor with a “D” quality rating for the AP-42 update. The prior AP-42 section for 

MSW landfills (U.S. EPA, 1998) does not include dioxin/furan emission factors for LFG-fired boilers. 

3.2.1.5 Boiler Summary 

Table 3-7 contains a summary of the combustion by-product data included in the LFG-fired boiler 

analysis for determining default emission factors for the AP-42 update. In addition, Table 3-7 provides 

the test methods used to measure these emissions data. 

A data quality rating of “A” was assigned to each of the boiler test reports listed in Table 3-7. All 

of the reports containing these data included adequate detail, the methodology appeared to be sound, and 

no problems were reported for the test runs. However, an overall data quality rating of “D” is 

recommended for each of the four default emission factors representing combustion by-products from 

boilers. This rating exemplifies the fact that the default factors were developed using “A”-rated test data 

from a small number of facilities. Although no specific bias is evident, it is not clear if the boilers tested 

represent a random sample of the existing LFG-fired boilers in the U.S. given that five or fewer data 

points were used to determine each default emission factor. 

54
 
TABLE 3-7. LANDFILL GAS-FIRED BOILER EMISSIONS DATA 

USED TO DEVELOP COMBUSTION BY-PRODUCT EMISSION FACTORS 

Test Report 

Reference Test Method 

Boiler 

Combustion ByProduct 

Emission Rate 

(kg/106

 dscm 

CH4) 

Emission Rate 

(lb/106

 dscf 

CH4) 

TR-167 SCAQMD Method 100.1 sampling with a CEMS NOX 591 37 

TR-220 SCAQMD Method 100.1 sampling with a CEMS NOX 563 35 

TR-268 ARB Method 1-100 NOX 1,040 65 

TR-291 SCAQMD Method 100.1 sampling with a CEMS NOX 593 37 

TR-292 EPA Method 7E (CEM) NOX 593 37 

NOX Default Emission Factor 677 42 

1998 NOX Default Emission Factora

 530 33 

TR-167 SCAQMD Method 100.1 sampling with a CEMS CO 94 6 

TR-220 SCAQMD Method 100.1 sampling with a CEMS CO 3 0.2 

TR-268 ARB Method 1-100 CO 116 7 

TR-292 EPA Method 10 (CEM) CO 250 16 

CO Default Emission Factor 116 7 

1998 CO Default Emission Factora

 90 5.7 

TR-167 SCAQMD Method 5.2 PM 48 3 

TR-188 

Environment Canada Report EPS 1/RM/8 

"Reference Method for Source Testing: 

Measurement of Releases of Particulate from 

Stationary Sources" 

PM 36 2 

TR-220 SCAQMD Method 5.1 PM 10 1 

TR-268 EPA Method 5 PM 71 4 

PM Default Emission Factor 41 3 

1998 PM Default Emission Factora

 130 8.2 

TR-220 CARB Method 428 Total dioxin/furan 2.22x10-6 1.38x10-7 

TR-268 Modified EPA Method 5 (ASME Semi-VOST) Total dioxin/furan 1.36x10-6 8.47x10-8 

TR-291 CARB Method 428 Total dioxin/furan 1.4x10-6 8.93x10-8 

TR-292 EPA Method 23 and EPA Method 8290 Total dioxin/furan 1.53x10-5 9.54x10-7 

Total Dioxin/Furan Default Emission Factor 5.1x10-6 3.2x10-7 

1998 Total Dioxin/Furan Default Emission Factora Not available Not available 

a

 – Default emission factor from the November 1998 AP-42 chapter 2.4. 

3.2.2 Internal Combustion (IC) Engine Combustion By-Product Emissions – Source Characterization, 

Test Methods and Results 

Combustion by-product emissions data for LFG-fired IC engines were submitted to EPA for a 

total of six landfills. Nitrogen oxide and carbon monoxide emissions were sampled and reported in units 

of ppm, lb/hr, or g/m3

 CH4 for all six engines. Three of the test reports also contain particulate matter 

emissions data, given in g/m3

 CH4. Five engine test reports have total dioxin/furan emissions in pg 

TEQ/m3

, or grams per hour (g/hr). Where possible, each of the emission data points was converted to 

kilograms per million dry standard cubic meters of CH4 (kg/106

 dscm CH4) to result in comparable 

emissions for a variety of LFG-fired engines. 

55
 
 

Of the six engine test reports used in the analysis, five engines (TR-189, TR-190, TR-266, TR272, TR-284) are Caterpillar gas engines. The remaining engine (TR-194) is a Waukesha gas engine. 

In addition to the newly-submitted test reports described above, there were data from six engine 

test reports used in the prior AP-42 update that were “A” or “B” quality that were also used in this 

analysis. Six data points for NOx, five for CO, and one for PM were used from the prior AP-42 update 

information. 

3.2.2.1 Nitrogen Oxides 

Three of the six test reports (TR-266, TR-272, TR-284) containing NOX emissions data were 

included in the analysis to determine a default emission factor. The emission rates provided for TR-189, 

TR-190, and TR-194 were excluded from the NOX analysis because samples were collected and analyzed 

using a portable combustion gas analyzer, which is not considered an acceptable test method. 

The maximum emission rate of 60,600 kg/106

 dscm CH4 for one engine (TR-284) is a suspected 

outlier when compared to the other emission rates. However, this test was witnessed by EPA staff and 

was thoroughly audited. Therefore, this potential outlier was included in the analysis because no datum 

should be rejected solely on the basis of statistical tests since there is a risk of rejecting an emission rate 

that represents actual emissions. 

Emission rates for the three engines included in the analysis, plus the six engines from the 

previous AP-42 update (BID-64, -67, -68, -98, -99, -101) range from 2,440 to 60,600 kg/106

 dscm CH4. 

The arithmetic mean emission rate for NOX for these LFG-fired engines is 11,600 kg/106

 dscm CH4. This 

average rate was selected as the default emission factor to represent engine NOX in the AP-42 update, 

with a quality rating of “C.” However, the user should consider the impact of the individual data point 

that is influencing this average when applying the default emission factor. For comparison, the median 

value of the engine NOx data points results in a value of 4,740 kg/106

 dscm CH4, which compares more 

closely with the previous default factor in AP-42 (U.S. EPA, 1998). The previous default emission factor 

was 4,000 kg/106

 dscm CH4 with a quality rating of “D.” 

3.2.2.2 Carbon Monoxide 

Three of the six engine test reports (TR-266, TR-272, TR-284) containing CO emissions data 

were included in the analysis to determine a default emission factor. The emission rates provided for TR189, TR-190, and TR-194 were excluded from the CO analysis because samples were collected and 

analyzed using a portable combustion gas analyzer, which is not considered an acceptable test method for 

the AP-42 analysis. There are five emission data points from the prior AP-42 update that are included in 

this analysis (BID-64, -67, -98, -99, -101). 

Carbon monoxide emission rates range from 6,400 to 11,700 kg/106

 dscm CH4. The arithmetic 

mean emission rate for CO is 8,460 kg/106

 dscm CH4, which was selected as the default emission factor 

with a “C” quality rating for the AP-42 update. The prior default factor in AP-42 (U.S. EPA, 1998) is 

7,500 kg/106

 dscm CH4 with a quality rating of “C.” 

3.2.2.3 Particulate Matter 

Particulate matter emissions are provided in three engine test reports (TR-189, TR-190, TR-194) 

and one data point from the prior AP-42 update (BID-98). These four PM emission rates range between 

43 and 772 kg/106

 dscm CH4. The arithmetic mean emission rate for PM is 232 kg/106 dscm CH4. This 

56
 
average rate was selected as the default to represent PM in the AP-42 update, with a quality rating of “D.” 

The 1998 AP-42 section for MSW landfills (U.S. EPA, 1998) has a default PM emission factor of 770 

kg/106

 dscm CH4 with a quality rating of “E.” 

3.2.2.4 Total Dioxin/Furan 

Five test reports (TR-189, TR-190, TR-194, TR-272, TR-284) contain measurement data for 

dioxins/furans. Emissions data for three engine test reports (TR-189, TR-190, TR-194) were excluded 

from the dioxin/furan analysis because data were only reported on a TEQ basis but total dioxin/furan on a 

mass basis was being used in the analysis to determine a default emission factor. Emission rates for the 

remaining two test reports (TR-272, TR-284) are below the method detection limit for all test runs using 

EPA Method 23. The emission rates for each of these reports are <2.15 x 10-10 kg/hr (1.73 x 10-6 kg/106 

dscm CH4) for TR-272 and <1.12 x 10-10 kg/hr (3.92 x 10-7 kg/106 dscm CH4) for TR-284. Therefore, a 

proper analysis cannot be conducted for total dioxin/furan emissions from LFG-fired engines until 

additional data become available. The prior version of the AP-42 section for MSW landfills (U.S. EPA, 

1998) does not include dioxin/furan emission factors for engines. 

3.2.2.5 IC Engine Summary 

Table 3-8 contains a summary of the combustion by-product data included in the LFG-fired IC 

engine analysis for determining default emission factors for the AP-42 update. In addition, Table 3-8 

provides the test methods used to measure these emissions data. 

A data quality rating of “A” (except for BID-99 and PM for BID-98, which have “B” ratings) was 

assigned to each of the IC engine test reports listed in Table B. All of the reports containing these data 

included adequate detail, the methodology appeared to be sound, and no problems were reported for the 

test runs. However, overall data quality ratings of “C” for NOx and CO, and “D” for PM, are 

recommended for default emission factors representing combustion by-products from engines. These 

ratings exemplify the fact that the default factors were developed using “A” and “B”-rated test data from 

a reasonable to small number of facilities. Although no specific bias is evident, it is not clear if the 

engines tested represent a random sample of the existing LFG-fired engines in the U.S. given that 

between four (PM) to nine (NOx) data points were used to determine each default emission factor. 

TABLE 3-8. LANDFILL GAS-FIRED IC ENGINE EMISSIONS DATA 

USED TO DEVELOP COMBUSTION BY-PRODUCT EMISSION FACTORS 

Test Report 

Reference Test Method 

IC Engine 

Combustion ByProduct 

Emission Rate 

(kg/106

 dscm 

CH4) 

Emission Rate 

(lb/106

 dscf 

CH4) 

TR-266 SCAQMD Method 100.1 and EPA Methods 6C 

and 7E NOX 8,170 510 

TR-272 EPA Method 7E (CEM) NOX 5,680 355 

TR-284 EPA Method 7E (CEM) NOX 60,600 3,780 

BID-64 EPA Method 10 (CEM) NOX 2,470 154 

BID-67 EPA Method 10 (CEM) NOX 2,500 156 

BID-68 EPA Method 7E (CEM) NOX 2,440 152 

BID-98 CARB Method 1-100 NOX 4,540 283 

BID-99 Unspecified NOX 4,740 296 

BID-101 Phenoldisulfonic Acid (PDSA) method NOX 13,400 839 

57
 
TABLE 3-8 (CONTINUED). LANDFILL GAS-FIRED IC ENGINE EMISSIONS DATA
 

USED TO DEVELOP COMBUSTION BY-PRODUCT EMISSION FACTORS 

Test Report 

Reference Test Method 

IC Engine 

Combustion ByProduct 

Emission Rate 

(kg/106

 dscm 

CH4) 

Emission Rate 

(lb/106

 dscf 

CH4) 

NOX Default Emission Factor 11,600 725 

1998 NOX Default Emission Factora

 4,000 250 

TR-266 SCAQMD Method 100.1 and EPA Methods 6C 

and 7E CO 11,100 693 

TR-272 EPA Method 10 (CEM) CO 11,700 728 

TR-284 EPA Method 10 (CEM) CO 7,680 479 

BID-64 EPA Method 7E (CEM) CO 8,150 508 

BID-67 EPA Method 7E (CEM) CO 9,280 579 

BID-98 CARB Method 1-100 CO 6,810 425 

BID-99 Unspecified CO 6,400 399 

BID-101 TCA method CO 6,610 413 

CO Default Emission Factor 8,460 528 

1998 CO Default Emission Factora

 7,500 470 

TR-189 

Environment Canada Report EPS 1/RM/8 

“Reference Method for Source Testing: 

Measurement of Releases of Particulate from 

Stationary Sources” 

PM 56.6 3.5 

TR-190 

Environment Canada Report EPS 1/RM/8 

“Reference Method for Source Testing: 

Measurement of Releases of Particulate from 

Stationary Sources” 

PM 54.8 3.4 

TR-194 

Environment Canada Report EPS 1/RM/8 

“Reference Method for Source Testing: 

Measurement of Releases of Particulate from 

Stationary Sources” 

PM 43.1 2.7 

BID-98 EPA Method 5 PM 772 48 

PM Default Emission Factor 232 14.5 

1998 PM Default Emission Factora

 770 48 

a

 – Default emission factor from the November 1998 AP-42 chapter 2.4. 

3.2.2.6 Emission Factors in Alternate Units of Measure 

The preceding tables present the emission factors in the units used for updating the MSW 

Landfills section of AP-42 (U.S. EPA, 1998). However, EPA’s Landfill Methane Outreach Program 

(LMOP) and other organizations may require emission factors presented in units more convenient to the 

LFG energy project or combustion device being studied. Therefore, Table 3-9 presents the boiler data in 

units of lb/MMBtu heat input and lb/MWh of electricity produced, and Table 3-10 presents the engine 

data in lb/MMBtu heat input, and lb/MWh and g/brake horsepower-hour (bhph). The heat rate assumed 

in these conversions is 10,700 Btu/kWh for boilers, and 11,100 Btu/kWh for engines. These are 

consistent with factors used by the LMOP program and are based on engine manufacturer’s literature and 

other information provided to LMOP by manufacturers and distributors. The heat content of CH4 is 1,012 

Btu/dscf (Perry, 1963). 

58
 
TABLE 3-9. LANDFILL GAS-FIRED BOILER EMISSIONS DATA 

USED TO DEVELOP COMBUSTION BY-PRODUCT EMISSION FACTORS (ALTERNATE 

UNIT FACTORS) 

Test Report 

Reference Test Method 

Boiler 

Combustion ByProduct 

Emission Rate 

(lb/MMBtu) 

(fuel input) 

Emission Rate 

(lb/MWh) 

TR-167 SCAQMD Method 100.1 sampling with a CEMS NOX 0.04 0.4 

TR-220 SCAQMD Method 100.1 sampling with a CEMS NOX 0.03 0.4 

TR-268 ARB Method 1-100 NOX 0.06 0.7 

TR-291 SCAQMD Method 100.1 sampling with a CEMS NOX 0.04 0.4 

TR-292 EPA Method 7E (CEM) NOX 0.04 0.4 

NOX Default Emission Factor 0.04 0.4 

1998 NOX Default Emission Factora

 0.03 0.3 

TR-167 SCAQMD Method 100.1 sampling with a CEMS CO 0.01 0.1 

TR-220 SCAQMD Method 100.1 sampling with a CEMS CO 2.0x10-4 2.1x10-3 

TR-268 ARB Method 1-100 CO 0.01 0.1 

TR-292 EPA Method 10 (CEM) CO 0.02 0.2 

CO Default Emission Factor 0.01 0.1 

1998 CO Default Emission Factora

 0.01 0.1 

TR-167 SCAQMD Method 5.2 PM 3.0x10-3 0.03 

TR-188 

Environment Canada Report EPS 1/RM/8 

“Reference Method for Source Testing: 

Measurement of Releases of Particulate from 

Stationary Sources” 

PM 2.2x10-3 0.02 

TR-220 SCAQMD Method 5.1 PM 6.0x10-4 0.01 

TR-268 EPA Method 5 PM 4.4x10-3 0.05 

PM Default Emission Factor 2.5x10-3 0.03 

1998 PM Default Emission Factora

 8.1x10-3 0.09 

TR-220 CARB Method 428 Total dioxin/furan 1.4x10-10 1.5x10-9 

TR-268 Modified EPA Method 5 (ASME Semi-VOST) Total dioxin/furan 8.4x10-11 9.0x10-10 

TR-291 CARB Method 428 Total dioxin/furan 8.8x10-11 9.4x10-10 

TR-292 EPA Method 23 and EPA Method 8290 Total dioxin/furan 9.4x10-10 1.0x10-8 

Total Dioxin/Furan Default Emission Factor 3.1x10-10 3.3 x10-9 

1998 Dioxin/Furan Default Emission Factora Not available Not available 

a

 – Default emission factor from the November 1998 AP-42 chapter 2.4, but converted to lb/MMBtu and lb/kWh units using 

1,012 Btu/dscf CH4 and 10,700 Btu/kWh, as discussed above. 

59
 
 

TABLE 3-10. LANDFILL GAS-FIRED IC ENGINE EMISSIONS DATA USED TO DEVELOP 

COMBUSTION BY-PRODUCT EMISSION FACTORS (ALTERNATE UNIT FACTORS) 

Test 

Report 

Reference Test Method 

IC Engine 

Combustion 

By-Product 

Emission 

Rate 

(lb/MMBtu) 

(fuel input) 

Emission 

Rate 

(lb/MWh) 

Emission 

Rate 

(g/bhph)a 

TR-266 SCAQMD Method 100.1 and EPA Methods 

6C and 7E NOX 0.5 5.6 2.0 

TR-272 EPA Method 7E (CEM) NOX 0.4 3.9 1.4 

TR-284 EPA Method 7E (CEM) NOX 3.7 41 15 

BID-64 EPA Method 10 (CEM) NOX 0.2 1.7 0.6 

BID-67 EPA Method 10 (CEM) NOX 0.2 1.7 0.6 

BID-68 EPA Method 7E (CEM) NOX 0.2 1.7 0.6 

BID-98 CARB Method 1-100 NOX 0.3 3.1 1.1 

BID-99 Unspecified NOX 0.3 3.2 1.2 

BID-101 Phenoldisulfonic Acid (PDSA) method NOX 0.8 9.2 3.3 

NOX Default Emission Factor 0.7 8.0 2.8 

1998 NOX Default Emission Factorb

 0.2 2.7 1.0 

TR-266 SCAQMD Method 100.1 and EPA Methods 

6C and 7E CO 0.7 7.6 2.7 

TR-272 EPA Method 10 (CEM) CO 0.7 8.0 2.8 

TR-284 EPA Method 10 (CEM) CO 0.5 5.3 1.9 

BID-64 EPA Method 7E (CEM) CO 0.5 5.6 2.0 

BID-67 EPA Method 7E (CEM) CO 0.6 6.4 2.3 

BID-98 CARB Method 1-100 CO 0.4 4.7 1.7 

BID-99 Unspecified CO 0.4 4.4 1.6 

BID-101 TCA method CO 0.4 4.5 1.6 

CO Default Emission Factor 0.5 5.8 2.1 

1998 CO Default Emission Factorb

 0.5 5.2 1.8 

TR-189 

Environment Canada Report EPS 1/RM/8 

“Reference Method for Source Testing: 

Measurement of Releases of Particulate from 

Stationary Sources” 

PM 3.5x10-3 3.9x10-2 1.4x10-2 

TR-190 

Environment Canada Report EPS 1/RM/8 

“Reference Method for Source Testing: 

Measurement of Releases of Particulate from 

Stationary Sources” 

PM 3.4x10-3 3.8x10-2 1.3x10-2 

TR-194 

Environment Canada Report EPS 1/RM/8 

“Reference Method for Source Testing: 

Measurement of Releases of Particulate from 

Stationary Sources” 

PM 2.7x10-3 3.0x10-2 1.1x10-2 

BID-98 EPA Method 5 PM 4.7 x10-2 5.3x10-1 1.9x10-1 

PM Default Emission Factor 1.4x10-2 1.6x10-1 5.6x10-2 

1998 PM Default Emission Factorb 4.7 x10-2 5.3 x10-1 1.9x10-1 

a

 – Per common practice, assumes a 5% energy loss from engine output in converting shaft energy to electricity. b

 – Default emission factor from the November 1998 AP-42 chapter 2.4, but converted to lb/MMBtu and lb/kWh units using 

1,012 Btu/dscf CH4 and 11,100 Btu/kWh, as discussed above. 

60 
3.2.3 Gas Turbine Data Summary 

Since the last update of the MSW Landfills section of AP-42 (U.S. EPA, 1998), no additional test 

data for LFG turbines has been received by EPA. Therefore, these emission factors remain the same as in 

the previous update. Supporting background information from the 1997 background information 

document for turbines is included in Appendix F to this document. 

References 

BID-64. Report of Emission Levels and Fuel Economics for Eight Waukesha 12V-AT25GL 

Units Located at the Johnston, Rhode Island Central Landfill, Waukesha Pearce Industries, Inc. 

Houston, TX , July 19, 1991. 

BID-67. Final Report for Emissions Compliance Testing of One Waukesha Engine Generator, 

Browning-Ferris Gas Services, Inc., Chicopee, MA, February 1994. 

BID-68. Final Report for Emissions Compliance Testing of Three Waukesha Engine Generators, 

Browning-Ferris Gas Services, Inc., Richmond, VA, February 1994. 

BID-98. Landfill Gas Engine Exhaust Emissions Test Report in Support of Modification to 

Existing IC Engine Permit at Bakersfield Landfill Unit #1, Pacific Energy Services, December 4, 

1990. 

BID-99. Addendum to Source Test Report for Superior Engine #1 at Otay Landfill, Pacific 

Energy Services, April 2, 1991. 

BID-101. Source Test Report 88-0096 of Emissions from an Internal Combustion Engine Fueled 

by Landfill Gas, Toyon Canyon Landfill, Pacific Energy Lighting Systems, South Coast Air 

Quality Management District, March 8, 1988. 

Perry, John H., ed. Chemical Engineers Handbook. McGraw-Hill Book Company: NY, 1963, 

Page 9-9. 

TR-163. Compliance Testing for SPADRA Landfill Gas-to-Energy Plant, Ebasco Constructors, 

Inc., November 1990. 

TR-167. 1997 Annual Compliance Source Testing Results for the Coyote Canyon Landfill Gas 

Recovery Facility Boiler, Laidlaw Gas Recovery Systems, January 1998. 

TR-188. Characterization of Emissions from a Power Boiler Fired with Landfill Gas, 

Environment Canada, Emissions Research and Measurement Division, March 2000. 

TR-189. Characterization of Emissions from 925 kWe Reciprocating Engine Fired with Landfill 

Gas, Environment Canada, Emissions Research and Measurement Division, December 2000. 

TR-190. Characterization of Emissions from 812 kWe Reciprocating Engine Fired with Landfill 

Gas, Environment Canada, Emissions Research and Measurement Division, December 1999. 

TR-194. Characterization of Emissions from 1 Mwe Reciprocating Engine Fired with Landfill 

Gas, Environment Canada, Emissions Research and Measurement Division, January 2002. 

61
 
 

TR-220. SCAQMD Performance Tests on the Spadra Energy Recovery from Landfill Gas 

(SPERG) Facility, County Sanitation Districts of Los Angeles County, April 1992. 

TR-266. Compliance Source Test Report – Landfill Gas-Fired Engine, Minnesota Methane, 

March 3, 1998. 

TR-268. Emission Testing at PERG – Maximum Boiler Load, County Sanitation Districts of Los 

Angeles County, December 1986. 

TR-272. Source Testing Final Report – Landfill A, U.S. Environmental Protection Agency, Air 

Pollution Prevention and Control Division, October 6, 2005. 

TR-284. Source Testing Final Report – Landfill C, U.S. Environmental Protection Agency, Air 

Pollution Prevention and Control Division, October 6, 2005. 

TR-291. PCDD/PCDF Emissions Tests on the Palos Verdes Energy Recovery from Landfill Gas 

(PVERG) Facility, Unit 2, County Sanitation Districts of Los Angeles County, February 1994. 

TR-292. Source Testing Final Report – Landfill E, U.S. Environmental Protection Agency, Air 

Pollution Prevention and Control Division, October 2005. 

U.S. Environmental Protection Agency (1997a). Procedures for Preparing Emission Factor 

Documents ,EPA-454/R-95-015, Office of Air Quality Planning and Standards, Research 

Triangle Park, NC, November 1997. 

U.S. Environmental Protection Agency (1998). Compilation of Air Pollutant Emission Factors, 

AP-42, Fifth Edition, Volume I: Stationary Point and Area Sources, Section 2.4 Municipal Solid 

Waste Landfills, Research Triangle Park, NC, November 1998. 

62
 
 

 

 

 

 

 

 

3.3 CONTROL DEVICE EFFICENCY DATA 

NMOC data was compiled for the various control devices and analyzed. This data consists of 

“A” and “B” data from the prior Municipal Solid Waste (MSW) Landfills section of AP-42 (U.S. EPA, 

1998), along with the data available from this update, all of which were rated as “A” quality. The 

following table (Table 3-11) summarizes the data, which is also found in Table 2.4-3 of the AP-42 

section. Appendix F contains the supporting data and calculations used to determine the control device 

efficiencies. 

Please note that the Landfill NSPS requirements are in 40 CFR 60.752(b)(2)(iii) for enclosed 

combustion devices (e.g., enclosed flares, boilers, engines, turbines) burning untreated LFG require 

reduction of NMOC by 98 weight % or reduce the outlet NMOC concentration to less than 20 ppmv, dry 

basis as hexane at 3% oxygen. Therefore, although some of the data show that observed control 

efficiencies may sometimes be less than 98%, the control device may still meet the regulatory 

requirements by meeting the 20 ppmv limit of NMOC (dry basis as hexane at 3% oxygen). 

Following the same criteria as described for the emission factors, the control device efficiency 

rankings were assigned as follows: Boiler – “D;” Flare – “A;” Engine – “D;” and Turbine – “E.” 

TABLE 3-11. NMOC CONTROL EFFICIENCY DATA ANALYSIS SUMMARY 

Number of 

Data Points Min (%) Max (%) Mean (%) 

Standard 

Deviation 

(%) 

95% 

Confidence 

Interval 

(± %) 

Boiler 5 95.9 99.6 98.6 1.6 1.4 

Flare 25 85.8 100.0 97.7 3.4 1.3 

Engine 3 94.6 99.7 97.2 2.6 2.9 

Avg of Boiler, Engine, Flare 97.8 

Turbine 2 91.5 97.3 94.4 4.1 134.8 

Historically, controlled emissions have been calculated with Equation 6. In this equation it is 

assumed that the LFG collection and control system operates 100 percent of the time. Minor durations of 

system downtime associated with routine maintenance and repair (i.e., 5 to 7 percent) will not appreciably 

affect emission estimates. The first term in Equation 6 accounts for emissions from uncollected LFG, 

while the second term accounts for emissions of the pollutant that were collected but not fully combusted 

in the control or utilization device: 

⎡

UMP x 

⎛

⎜

⎝

1− ηcol 

100 

⎞

⎟

⎠

⎤ ⎡ ⎥

⎦

+ ⎢

⎣

UMP x 

ηcol x 

100
 

⎛

⎜

⎝

1 − ηcnt 

100 

⎞

⎟

⎠

⎤ CM
 (6) ⎢

⎣

= ⎥

⎦ P

where: 

CMP = Controlled mass emissions of pollutant P, kg/yr; 

UMP = Uncontrolled mass emissions of P, kg/yr (from Equation 5); 

ηcol = Efficiency of the LFG collection system, % (recommended default is 75%); and 

ηcnt = Efficiency of the LFG control or utilization device, %. 

3.4 CONTROL DEVICE CARBON DIOXIDE, SULFUR DIOXIDE, AND HYDROGEN 

CHLORIDE EMISSIONS 

63
 
 

 

 

 

 

 

 

 

 

 

 

 

Controlled emissions of CO2 and sulfur dioxide (SO2) are best estimated using site-specific LFG 

constituent concentrations and mass balance methods (Nesbitt, 1996). If site-specific data are not 

available, the data in Tables 2-7, 2-8 and 2-9 can be used with the mass balance methods that follow. 

 Controlled CO2 emissions include emissions from the CO2 component of LFG and additional CO2 

formed during the combustion of LFG. The bulk of the CO2 formed during LFG combustion comes from 

the combustion of the CH4 fraction. Small quantities will be formed during the combustion of the NMOC 

fraction. However, this typically amounts to less than one percent of total CO2 emissions by weight. This 

contribution to the overall mass balance picture is also very small and does not have a significant impact 

on overall CO2 emissions (Nesbitt, 1996). 

The following equation which assumes a 100% combustion efficiency for CH4 can be used to 

estimate CO2 emissions from controlled landfills: 

⎛ ηcol ⎜

⎝

⎞

⎟

⎠ CM = UM + UM
 x x 2.75 (7) CO 2 CO 2 CH 4 100
 

where: 

CMCO2 = Controlled mass emissions of CO2, kg/yr (from Equation 5); 

UMCO2 = Uncontrolled mass emissions of CO2, kg/yr (from Equation 5); 

UMCH4 = Uncontrolled mass emissions of CH4, kg/yr; 

ηcol = Efficiency of the LFG collection system, % (recommended default is 75%); 

and 

2.75 = Ratio of the molecular weight of CO2 to the molecular weight of CH4. 

To prepare estimates of SO2 emissions, data on the concentration of reduced sulfur compounds 

within the LFG are needed. The best way to prepare this estimate is with site-specific information on the 

total reduced sulfur content of the LFG. Often these data are expressed in ppmv as sulfur (S). Equations 

4 and 5 should be used first to determine the uncontrolled mass emission rate of reduced sulfur 

compounds as sulfur. Then, the following equation can be used to estimate SO2 emissions: 

ηcol CM
 = UM
 x x 2.0 (8) SO2 S 100
 

where: 

CMSO2 = Controlled mass emissions of SO2, kg/yr; 

UMS = Uncontrolled emissions of reduced sulfur compounds as sulfur, kg/yr; 

ηcol = Efficiency of the LFG collection system, %; and 

2.0 = Ratio of the molecular weight of SO2 to the molecular weight of S. 

The next best method to estimate SO2 concentrations, if site-specific data for total reduced sulfur 

compounds as sulfur are not available, is to use site-specific data for speciated reduced sulfur compound 

concentrations. These data can be converted to ppmv as S with Equation 9. After the total reduced sulfur 

as S has been obtained from Equation 9, then Equations 4, 5, and 8 can be used to derive SO2 emissions. 

64
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

n 

P C (9) 
 S =
 C P x S

i 1 

where: 

CS = Concentration of total reduced sulfur compounds, ppmv as S (for use in Equation 4); 

CP = Concentration of each reduced sulfur compound, ppmv; 

SP = Number of moles of S produced from the combustion of each reduced sulfur compound 

(i.e., 1 for sulfides, 2 for disulfides); and 

n = Number of reduced sulfur compounds available for summation. 

If no site-specific data are available, values of 47 and 33 ppmv can be used for CS in the gas from 

landfills having a majority of the waste in place before 1992 and from landfills having a majority of the 

waste in place after 1992, respectively. These values were obtained by using the default concentrations 

presented in Tables 2-9 and 2-7 for reduced sulfur compounds and Equation 9. 

Hydrochloric acid [hydrogen chloride (HCl)] emissions are formed when chlorinated compounds 

in LFG are combusted in control equipment. The best methods to estimate HCl emissions are mass 

balance methods that are analogous to those presented above for estimating SO2 emissions. Hence, the 

best source of data to estimate HCl emissions is site-specific LFG data on total chloride [expressed in 

ppmv as the chloride ion (Cl-

)]. However, emission estimates may be underestimated, since not every 

chlorinated compound in the LFG will be represented in the site test report (i.e., only those that the 

analytical method specifies). If these data are not available, then total chloride can be estimated from data 

on individual chlorinated species using Equation 10 below. 

n 

∑= 

∑ i= 1

C = C x Cl (10) 
 Cl P P 

where: 

CCl = Concentration of total chloride, ppmv as Cl­

 (for use in Equation 4); 

CP = Concentration of each chlorinated compound, ppmv; 

ClP = Number of moles of Cl­

 produced from the combustion of each mole of chlorinated 

compound (i.e., 3 for 1,1,1-trichloroethane); and 

n = Number of chlorinated compounds available for summation. 

After the total chloride concentration (CCl) has been estimated, Equations 4 and 5 should be used 

to determine the total uncontrolled mass emission rate of chlorinated compounds as chloride ion (UMCl). 

This value is then used in Equation 11, below, to derive HCl emission estimates: 

ηcol ηcnt 

100 100 

CM = UM
 x x 1.03 x (11) 
 HCl C1 

where: 

CMHCl = Controlled mass emissions of HCl, kg/yr; 

UMCl = Uncontrolled mass emissions of chlorinated compounds as chloride, kg/yr (from 

Equations 4 and 5); 

ηcol = Efficiency of the LFG collection system, percent; 

1.03 = Ratio of the molecular weight of HCl to the molecular weight of Cl-

; and 

ηcnt = Control efficiency of the LFG control or utilization device, percent. 

65
 
 

 

In estimating HCl emissions, it is assumed that all of the chloride ion from the combustion of 

chlorinated LFG constituents is converted to HCl. If an estimate of the control efficiency, ηcnt, is not 

available, then the control efficiency for the equipment listed in Table 3-11 should be used. This 

assumption is recommended to assume that HCl emissions are not under-estimated. 

If site-specific data on total chloride or speciated chlorinated compounds are not available, then 

default values of 42 and 74 ppmv can be used for CCl in the gas from landfills having a majority of the 

waste in place before 1992 and from landfills having a majority of the waste in place after 1992, 

respectively. These values were derived from the default LFG constituent concentrations presented in 

Tables 2-11 and 2-8. As mentioned above, use of this default may produce underestimates of HCl 

emissions since it is based only on those compounds for which analyses have been performed. The 

constituents listed in Table 2-11 and 2-8 are likely not all of the chlorinated compounds present in LFG. 

References 

Letter and attached documents from C. Nesbitt, Los Angeles County Sanitation Districts, to K. 

Brust, E.H. Pechan and Associates, Inc., December 6, 1996. 

66
 
 

4.0 MERCURY EMISSIONS DATA ANALYSIS 

4.1 MERCURY IN RAW LANDFILL GAS 

Mercury concentration data for raw LFG were submitted to EPA for a total of 17 landfills. These 

landfills are represented by nine emissions test reports because one test report (TR-211) contains mercury 

data for eight landfills in the state of Washington and another (TR-293) contains data for two landfills. 

This Washington report includes multiple measurements for two of the landfills sampled (TR-211a, TR211f) because the LFG streams are split between the flare and the energy recovery facility at each landfill. 

A single average concentration for each of these landfills was calculated to represent each landfill so as 

not to disproportionately affect the overall average concentration being determined to estimate mercury 

emissions for an average landfill. 

Total mercury, elemental mercury, monomethyl mercury, and dimethyl mercury are the four 

forms of mercury sampled and analyzed at these 17 landfills. Mercury concentrations are reported in 

either nanograms per cubic meter (ng/m3

) or milligrams per dry standard cubic foot (mg/dscf). These 

concentrations were converted to common units of parts per million by volume (ppmv), assuming 

standard conditions of 20 °C and one atmosphere. 

4.1.1 Total Mercury 

All nine of the test reports (TR-196, TR-211, TR-212, TR-272, TR-273, TR-284, TR-287, TR292, TR-293), representing 17 landfills, contain measurement data for total mercury. Concentrations for 

two landfills were excluded from the total mercury analysis because samples were collected from a 

leachate well open to the atmosphere for one landfill (TR-211c) and from a passive gas well, with 

ambient air present, for another landfill (TR-211d). 

Total mercury was sampled and analyzed using EPA Method 1631 for 14 of the 17 landfills. The 

test report for the landfill (TR-196) used CARB Draft Method 436 (adopted as CARB Method 436 in July 

1997), Determination of Multiple Metals Emissions from Stationary Sources, to determine total mercury 

concentration. This test report reveals total mercury concentrations below the method detection limit 

(<4.08 x 10-6 ppmv) for all three test runs. Based on guidance for detection limits contained in EPA’s 

Procedures for Preparing Emission Factor Documents (U.S. EPA, 1997a), half of the detection limit (2.04 

x 10-6 ppmv) was used to represent the average concentration of total mercury for this landfill. This 

concentration represents the minimum concentration used in the analysis. Another test report (TR-293) 

used method SW-846 Method 7473, “Mercury in Solids and Solutions by Thermal Decomposition, 

Mercury Amalgamation, and Atomic Adsorption Spectroscopy” and CFR Part 60 Method 30B, 

“Determination of Total Vapor Phase Mercury Emissions from Coal-Fired Combustion Sources Using 

Carbon Sorbent Tubes” to determine total mercury. 

Total mercury concentrations for the 15 landfills included in the analysis range from 2.04 x 10-6 

to 9.61 x 10-4 ppmv. The maximum concentration of 9.61 x 10-4 ppmv for one landfill (TR-211g) is a 

suspected outlier when compared to the other concentrations. However, the maximum concentration was 

included in the analysis because no datum should be rejected solely on the basis of statistical tests since 

there is a risk of rejecting a concentration that represents actual emissions. The test report containing this 

suspected outlier (TR-211) is for eight landfills in the state of Washington. This report states that total 

mercury levels observed at these Washington landfills are in the range of 25 to 8,000 ng/m3

 (3.0 x 10-6 to 

9.6 x 10-4 ppmv) which generally agrees with concentrations previously reported by Lindberg et al., 2001. 

The arithmetic mean concentration for total mercury for the 13 landfills is 1.2 x 10-4 ppmv. This 

average concentration was selected as the default to represent total mercury in the AP-42 update. The 

67
 
 

previous default concentration in AP-42 (U.S. EPA, 1998) is 2.92 x 10-4 ppmv with a quality rating of 

“E.” 

4.1.2 Elemental Mercury 

Six test reports (TR-272, TR-273, TR-284, TR-287, TR-292, TR-293), representing seven 

landfills, include elemental mercury concentrations that were measured by the LUMEX Instrument. 

Elemental mercury concentrations range from 7.0 x 10-6 to 3.9 x 10-4 ppmv. The arithmetic mean 

concentration for elemental mercury is 7.7 x 10-5 ppmv, which was selected as the default concentration 

for the AP-42 update. The previous version of the AP-42 section for MSW landfills (U.S. EPA, 1998) 

does not include elemental mercury because no data were available to speciate total mercury into the 

elemental form. 

4.1.3 Monomethyl Mercury 

Monomethyl mercury concentrations are contained in seven test reports (TR-212, TR-272, TR273, TR-284, TR-287, TR-292, TR-293) representing eight landfills. Five of these were sampled and 

analyzed using EPA draft method 1630. One test report (TR-293) used cold-vapor atomic fluorescence 

spectroscopy (CVAFS). The overall range of concentrations is 4.5 x 10-8 to 2.0 x 10-6 ppmv. The 

arithmetic mean concentration for monomethyl mercury for the six landfills is 3.8 x 10-7 ppmv. This 

average concentration was selected as the default to represent total mercury in the AP-42 update. The 

prior AP-42 section for MSW landfills (U.S. EPA, 1998) does not include monomethyl mercury because 

no data were available to speciate total mercury into the organic forms. 

4.1.4 Dimethyl Mercury 

Eight test reports (TR-211, TR-212, TR-272, TR-273, TR-284, TR-287, TR-292, TR-293), 

representing 16 landfills, contain measurement data for dimethyl mercury. Concentrations for two 

landfills were excluded from the dimethyl mercury analysis because samples were collected from a 

leachate well open to the atmosphere for one landfill (TR-211c) and from a passive gas well, with 

ambient air present, for another landfill (TR-211d). Concentrations thought to be biased low were 

excluded for two additional landfills (TR-272, TR-273) because spike recoveries are well below normally 

acceptable levels. 

Dimethyl mercury was sampled and analyzed using EPA Method 1630 Appendix A for five test 

reports. The remaining test report, representing two landfills, used CVAFS. 

Dimethyl mercury concentrations range from 2.3 x 10-7 to 5.5 x 10-6 ppmv. The arithmetic mean 

concentration for dimethyl mercury is 2.5 x 10-6 ppmv, which was selected as the default concentration 

for the AP-42 update. The prior version of the AP-42 section for MSW landfills (U.S. EPA, 1998) does 

not include dimethyl mercury because no data were available to speciate total mercury into the organic 

forms. 

4.1.5 Mercury Data Summary 

Table 4-1 contains a summary of the mercury data included in the raw LFG analysis for 

determining default concentrations for the AP-42 update. Appendix E presents statistical data graphs of 

the mercury data. 

A data quality rating of “A” was assigned to each of the individual mercury test data contained in 

Table 4-1. All of the reports containing these data included adequate detail, the methodology appeared to 

68
 
 

be sound, and no problems were reported for the valid test runs. An overall data quality rating of “B” for 

each of the four default concentrations representing each mercury compound is recommended. This 

rating exemplifies the fact that the default concentrations were developed from “A”-rated test data from a 

moderate number of facilities. Although no specific bias is evident, is not clear if the landfills tested 

represent a random sample of landfills in the U.S. In addition, less than 20 data points were used to 

determine each default concentration. 

TABLE 4-1. RAW LANDFILL GAS MERCURY DATA USED TO DETERMINE AP-42 

DEFAULT CONCENTRATIONS 

Test Report 

Reference Mercury Test Method 

Mercury 

Compound 

Concentration 

(ppmv) 

TR-211a EPA Method 1630 Appendix A Dimethyl 1.9 x 10-6 

TR-211b EPA Method 1630 Appendix A Dimethyl 1.10 x 10-6 

TR-211e EPA Method 1630 Appendix A Dimethyl 7.4 x 10-7 

TR-211f EPA Method 1630 Appendix A Dimethyl 2.59 x 10-6 

TR-211g EPA Method 1630 Appendix A Dimethyl 4.81 x 10-6 

TR-211h EPA Method 1630 Appendix A Dimethyl 3.00 x 10-6 

TR-212 EPA Method 1630 Appendix A Dimethyl 3.97 x 10-6 

TR-284 EPA Method 1630 Appendix A Dimethyl 1.54 x 10-6 

TR-287 EPA Method 1630 Appendix A Dimethyl 5.32 x 10-6 

TR-292 EPA Method 1630 Appendix A Dimethyl 5.48 x 10-6 

TR-293a CVAFS Dimethyl 2.3 x 10-7 

TR-293b CVAFS Dimethyl 6.8 x 10-7 

Dimethyl Mercury Default Concentration 2.5 x 10-6 

TR-272 LUMEX Instrument Elemental 3.69 x 10-5 

TR-273 LUMEX Instrument Elemental 7.0 x 10-6 

TR-284 LUMEX Instrument Elemental 1.2 x 10-5 

TR-287 LUMEX Instrument Elemental 3.33 x 10-5 

TR-292 LUMEX Instrument Elemental 5.28 x 10-5 

TR-293a LUMEX Instrument Elemental 3.9 x 10-4 

TR-293b LUMEX Instrument Elemental 5.6 x 10-6 

Elemental Mercury Default Concentration 7.7 x 10-5 

TR-212 EPA Draft Method 1631 Monomethyl 1.446 x 10-7 

TR-272 EPA Draft Method 1630 Monomethyl 4 x 10-8 

TR-273 EPA Draft Method 1630 Monomethyl 1.3 x 10-7 

TR-284 EPA Draft Method 1630 Monomethyl 4.4 x 10-7 

TR-287 EPA Draft Method 1630 Monomethyl 2.76 x 10-7 

TR-292 EPA Draft Method 1630 Monomethyl 6.0 x 10-7 

TR-293a CVAFS Monomethyl 1.4 x 10-6 

TR-293b CVAFS Monomethyl 2.0 x 10-6 

Monomethyl Mercury Default Concentration 3.8 x 10-7 

69
 
 

 

TABLE 4-1 (CONTINUED). RAW LANDFILL GAS MERCURY DATA USED TO DETERMINE 

AP-42 DEFAULT CONCENTRATIONS 

Test Report 

Reference Mercury Test Method 

Mercury 

Compound 

Concentration 

(ppmv) 

TR-196 CARB Draft Method 436 Total 2.04 x 10-6 

TR-211a EPA Method 1631 Total 5.41 x 10-6 

TR-211b EPA Method 1631 Total 1.4098 x 10-4 

TR-211e EPA Method 1631 Total 1.13 x 10-5 

TR-211f EPA Method 1631 Total 2.767 x 10-5 

TR-211g EPA Method 1631 Total 9.6083 x 10-4 

TR-211h EPA Method 1631 Total 3.029 x 10-5 

TR-212 EPA Method 1631 Total 4.89 x 10-5 

TR-272 EPA Method 1631 Total 7.58 x 10-5 

TR-273 EPA Method 1631 Total 2.45 x 10-5 

TR-284 EPA Method 1631 Total 5.10 x 10-5 

TR-287 EPA Method 1631 Total 8.87 x 10-5 

TR-292 EPA Method 1631 Total 1.751 x 10-4 

TR-293a SW-846 Method 7473 / CFR Part 60 Method 30B Total 6.0 x 10-4 

TR-293b SW-846 Method 7473 / CFR Part 60 Method 30B Total 5.2 x 10-6 

Total Mercury Default Concentration 1.2 x 10-4 

4.2 POST-COMBUSTION MERCURY EMISSIONS 

Burning LFG in combustion devices (control devices), including flares, engines, turbines, and 

boilers, may change the chemical species of mercury originally in the raw LFG but does not reduce the 

total quantity of mercury released. The amount of total mercury released from any combustion outlet is 

directly related to the amount of total mercury contained in the raw LFG. In other words, mercury 

emissions from landfills will be released to the atmosphere regardless of whether the LFG is combusted. 

However, combustion of LFG can convert organic forms of mercury, such as dimethyl mercury and 

monomethyl mercury, to less toxic inorganic forms, such as elemental mercury (Lindberg et al., 2001). 

The previous version of the AP-42 section for MSW landfills (U.S. EPA, 1998) has the following 

footnote for Table 2.4-3. Control Efficiencies for LFG Constituents: “For any equipment, the control 

efficiency for mercury should be assumed to be 0.” However, we note that use of activated carbon 

control technology (e.g., fixed beds) is capable of achieving significant reductions in mercury emission 

rates. This technology is used for the control of mercury emissions from small municipal waste and 

hospital incinerator units. It is uncertain whether this particular technology is feasible for LFG 

combustion applications. 

Total mercury concentrations from combustion outlets were provided for five landfills (TR-272, 

TR-273, TR-284, TR-287, TR-292), representing outlet emissions from two flares, two engines, and one 

boiler. Total mercury was measured using EPA Method 29 for all five landfills. Concentrations for four 

of these landfills (TR-272, TR-273, TR-284, TR-287) are below the method detection limit for all three 

test runs. Based on guidance for detection limits contained in EPA’s Procedures for Preparing Emission 

Factor Documents (U.S. EPA, 1997a), half of the detection limit should be used to represent the average 

concentration of total mercury for each of these four landfills. However, these halved concentrations are 

greater than the detect value for the total mercury concentration from the remaining landfill tested (TR292). Therefore, as directed in the EPA procedures document, these four halved concentrations should 

not be used in determining a default concentration for post-combustion total mercury emissions. In 

70
 
addition, elemental mercury concentrations were provided for post-combustion engine emissions from 

two landfills (TR-272, TR-284), using the LUMEX Instrument. 

Due to the limited post-combustion mercury data provided and the knowledge that mercury in 

raw LFG is not destroyed through combustion but rather converted from organic to inorganic forms, it is 

recommended that default concentrations for post-combustion mercury emissions not be developed at this 

time. If additional data become available, then these factors may be explored further. 

References 

Bloom, N.S. 1999. Method validation study for dimethyl mercury in air. Final report for US 

Army Corps of Engineers. Available from Frontier Geosciences, Seattle, WA. 

Bloom, N.S., and W.F. Fitzgerald. 1988. Determination of volatile mercury species at the 

picogram level by low-temperature gas chromatography with cold-vapour atomic fluorescence 

detection. Analytica Chimica Acta 208:151. 

Carpi, A., S.E. Lindberg, E.M. Prestbo, and N.S. Bloom. 1997. Methyl mercury contamination 

and emission to the atmosphere from soil amended with municipal sewage sludge. Journal of 

Environmental Quality 26:1650-1655. 

Lindberg, S.E., D. Wallschläger, E.M. Prestbo, N.S. Bloom, J. Price, and D. Reinhart. 2001. 

Methylated mercury species in municipal waste landfill gas sampled in Florida, USA. 

Atmospheric Environment 35:4011-4015. 

TR-196. Results of the Biennial Criteria and AB 2588 Air Toxics Source Test on the Simi Valley 

Landfill Flare, Simi Valley Landfill and Recycling Center, April 1997. 

TR-211. Determination of Total and Dimethyl Mercury in Raw Landfill Gas with Site Screening 

for Elemental Mercury at Eight Washington State Landfills, Washington State Department of 

Ecology, July 2003. 

TR-212. Determination of Total, and Monomethyl Mercury in Raw Landfill Gas at the Central 

Solid Waste Management Center, Delaware Solid Waste Authority, February 2003. 

TR-272. Source Testing Final Report - Landfill A, U.S. Environmental Protection Agency, Air 

Pollution Prevention and Control Division, October 6, 2005. 

TR-273. Source Testing Final Report - Landfill B, U.S. Environmental Protection Agency, Air 

Pollution Prevention and Control Division, October 6, 2005. 

TR-284. Source Testing Final Report - Landfill C, U.S. Environmental Protection Agency, Air 

Pollution Prevention and Control Division, October 6, 2005. 

TR-287. Source Testing Final Report - Landfill D, U.S. Environmental Protection Agency, Air 

Pollution Prevention and Control Division, October 6, 2005. 

TR-292. Source Testing Final Report - Landfill E, U.S. Environmental Protection Agency, Air 

Pollution Prevention and Control Division, October 2005. 

71
 
TR-293. Quantifying Uncontrolled Air Emissions From Two Florida Landfills – Draft Final 

Report. U.S. EPA Air Pollution Prevention and Control Division, March 26, 2008. 

U.S. Environmental Protection Agency (1997a). Procedures for Preparing Emission Factor 

Documents ,EPA-454/R-95-015, Office of Air Quality Planning and Standards, Research 

Triangle Park, NC, November 1997. 

U.S. Environmental Protection Agency (1998). Compilation of Air Pollutant Emission Factors, 

AP-42, Fifth Edition, Volume I: Stationary Point and Area Sources, Section 2.4 Municipal Solid 

Waste Landfills, Research Triangle Park, NC, November 1998. 

72
 
5.0 AP-42 SECTION 2.4 

Section 2.4 of AP-42 is presented in the following pages as it would appear in the AP-42 update. Please 

note that until this is formally released through EPA’s Technology Transfer Network (TTN) 

Clearinghouse for Inventories & Emissions (http://www.epa.gov/ttn/chief/ap42/), the factors and 

information contained in this section are regarded as draft. 

2.4 MUNICIPAL SOLID WASTE LANDFILLS 

2.4.1 General 1-4 

A municipal solid waste (MSW) landfill unit is a discrete area of land or an excavation that 

receives household waste, and that is not a land application unit, surface impoundment, injection well, or 

waste pile. An MSW landfill unit may also receive other types of wastes, such as commercial solid 

waste, nonhazardous sludge, and industrial solid waste. In addition to household and commercial wastes, 

the other waste types potentially accepted by MSW landfills include (most landfills accept only a few of 

the following categories): 

Χ Municipal sludge, 

Χ Municipal waste combustion ash, 

Χ Infectious waste, 

Χ Small-quantity generated hazardous waste; 

Χ Waste tires, 

Χ Industrial non-hazardous waste, 

Χ Conditionally exempt small quantity generator (CESQG) hazardous waste, 

Χ Construction and demolition waste, 

Χ Agricultural wastes, 

Χ Oil and gas wastes, and 

Χ Mining wastes. 

The information presented in this section applies only to landfills which receive primarily MSW. This 

information is not intended to be used to estimate emissions from landfills which receive large quantities 

of other waste types such as industrial waste, or construction and demolition wastes. These other wastes 

exhibit emissions unique to the waste being landfilled. 

In the United States in 2006, approximately 55 percent of solid waste was landfilled, 13 percent 

was incinerated, and 32 percent was recycled or composted. There were an estimated 1,754 active MSW 

landfills in the United States in 2006. These landfills were estimated to receive 138 million tons of waste 

annually, with 55 to 60 percent reported as household waste, and 35 to 45 percent reported as commercial 

waste.79 

2.4.2 Process Description 2,5 

The majority of landfills currently use the “area fill” method which involves placing waste on a 

landfill liner, spreading it in layers, and compacting it with heavy equipment. A daily soil cover is spread 

over the compacted waste to prevent wind-blown trash and to protect the trash from scavengers and 

vectors. The landfill liners are constructed of soil (i.e., recompacted clay) and synthetics (i.e., high density 

polyethylene) to provide an impermeable barrier to leachate (i.e., water that has passed through the 

73
 
landfill) and gas migration from the landfill. Once an area of the landfill is completed, it is covered with a 

“cap” or “final cover” composed of various combinations of clay, synthetics, soil and cover vegetation to 

control the incursion of precipitation, the erosion of the cover, and the release of gases and odors from the 

landfill. 

2.4.3 Control Technology2,5,6 

The New Source Performance Standards (NSPS) and Emission Guidelines for air emissions from 

MSW landfills for certain new and existing landfills were published in the Federal Register on March 1, 

1996. Current versions of the NSPS and Emission Guidelines can be found at 40 CFR 60 subparts WWW 

and Cb, respectively. The regulation requires that Best Demonstrated Technology (BDT) be used to 

reduce MSW landfill emissions from affected new and existing MSW landfills if (1) the landfill has a 

design capacity of 2.5 million Mg (2.75 million tons) and 2.5 million cubic meters or more, and (2) the 

calculated uncontrolled emissions from the landfill are greater than or equal to 50 Mg/yr (55 tons/yr) of 

nonmethane organic compounds (NMOCs). The MSW landfills that are affected by the NSPS/Emission 

Guidelines are each new MSW landfill, and each existing MSW landfill that has accepted waste since 

November 8, 1987 or that has capacity available for future use. Control systems require: (1) a welldesigned and well-operated gas collection system, and (2) a control device capable of reducing nonmethane organic compounds (NMOCs) in the collected gas by 98 weight-percent (or to 20 ppmv, dry 

basis as hexane at 3% oxygen for an enclosed combustion device). Other compliance options include use 

of a flare that meets specified design and operating requirements or treatment of landfill gas (LFG) for 

use as a fuel. The National Emission Standards for Hazardous Air Pollutants (NESHAP) for MSW 

landfills was published in the Federal Register on January 16, 2003. It requires control of the same 

landfills, and the same types of gas collection and control systems as the NSPS. The NESHAP also 

requires earlier control of bioreactor landfills and contains a few additional reporting requirements for 

MSW landfills. 

Landfill gas collection systems consist of a series of vertical or horizontal perforated pipes that 

penetrate the waste mass and collect the gases produced by the decaying waste. These collection systems 

are classified as either active or passive systems. Active collection systems use mechanical blowers or 

compressors to create a vacuum in the collection piping to optimize the collection of LFG. Passive 

systems use the natural pressure gradient established between the encapsulated waste and the atmosphere 

to move the gas through the collection system. 

LFG control and treatment options include: (1) combustion of the LFG, and (2) treatment of the 

LFG for subsequent sale or use. Combustion techniques include techniques that do not recover energy 

(i.e., flares and thermal incinerators), and techniques that recover energy and generate electricity from the 

combustion of the LFG (i.e., gas turbines and reciprocating engines). Boilers can also be employed to 

recover energy from LFG in the form of steam. Flares combust the LFG without the recovery of energy, 

and are classified by their burner design as being either open or enclosed. Purification techniques are 

used to process raw LFG to either a medium-BTU gas using dehydration and filtration or as a higherBTU gas by removal of inert constituents using adsorption, absorption, and membranes. 

2.4.4 Emissions2,7 

Methane (CH4) and carbon dioxide (CO2) are the primary constituents of LFG, and are produced 

by microorganisms within the landfill under anaerobic conditions. Transformations of CH4 and CO2 are 

mediated by microbial populations that are adapted to the cycling of materials in anaerobic environments. 

Landfill gas generation proceeds through four phases. The first phase is aerobic [i.e., with oxygen (O2) 

available from air trapped in the waste] and the primary gas produced is CO2. The second phase is 

characterized by O2 depletion, resulting in an anaerobic environment, where large amounts of CO2 and 

some hydrogen (H2) are produced. In the third phase, CH4 production begins, with an accompanying 

74
 
 

reduction in the amount of CO2 produced. Nitrogen (N2) content is initially high in LFG in the first 

phase, and declines sharply as the landfill proceeds through the second and third phases. In the fourth 

phase, gas production of CH4, CO2, and N2 becomes fairly steady. The duration of each phase and the 

total time of gas generation vary with landfill conditions (i.e., waste composition, design management, 

and anaerobic state). 

Typically, LFG also contains NMOC and volatile organic compounds (VOC). NMOC result 

from either decomposition by-products or volatilization of biodegradable wastes. Although NMOC are 

considered trace constituents in LFG, the NMOC and VOC emission rates could be “major” with respect 

to Prevention of Significant Deterioration (PSD) and New Source Review (NSR) requirements. This 

NMOC fraction often contains various organic hazardous air pollutants (HAP), greenhouse gases (GHG), 

compounds associated with stratospheric ozone depletion and volatile organic compounds (VOC). 

However, in MSW landfills where contaminated soils from storage tank cleanups are used as daily cover, 

much higher levels of NMOC have been observed. As LFG migrates through the contaminated soil, it 

adsorbs the organics, resulting in the higher concentrations of NMOC and any other contaminant in the 

soil. In one landfill where contaminated soil was used as daily cover, the NMOC concentration in the 

LFG was 5,870 ppm as compared to the AP-42 average value of 838 ppm. While there is insufficient 

data to develop a factor or algorithm for estimating NMOC from contaminated daily cover, the emissions 

inventory developer should be aware to expect elevated NMOC concentrations from these landfills. 

Other emissions associated with MSW landfills include combustion products from LFG control 

and utilization equipment (i.e., flares, engines, turbines, and boilers). These include carbon monoxide 

(CO), oxides of nitrogen (NOX), sulfur dioxide (SO2), hydrogen chloride (HCl), particulate matter (PM) 

and other combustion products (including HAPs). PM emissions can also be generated in the form of 

fugitive dust created by mobile sources (i.e., garbage trucks) traveling along paved and unpaved surfaces. 

The reader should consult AP-42 Volume I Sections 13.2.1 and 13.2.2 for information on estimating 

fugitive dust emissions from paved and unpaved roads. 

One pollutant that can very greatly between landfills is hydrogen sulfide (H2S). H2S is normally 

present in LFG at levels ranging from 0 to 90 ppm, with an average concentration of 33 ppm. However, a 

recent trend at some landfills has been the use of construction and demolition waste (C&D) as daily 

cover. Under certain conditions that are not well understood, some microorganisms will convert the 

sulfur in the wall-board of C&D waste to H2S. At these landfills, H2S concentrations can be significantly 

higher than at landfills that do not use C&D waste as daily cover. While H2S measurements are not 

available for landfills using C&D for daily cover, the State of New Hampshire among others have noted 

elevated H2S odor problems at these landfills and have assumed that H2S concentrations have increased, 

similarly. In a series of studies at 10 landfills in Florida where a majority of the waste is composed of 

C&D material, the concentration of H2S concentration spanned a range from less than the detection limit 

of the instrument (0.003 ppmv) up to 12,000 ppmv.8

 Another study that was conducted used flux boxes 

to measure uncontrolled emissions of H2S at five landfills in Florida. This study reported a range of H2S 

emissions between 0.192 and 1.76 mg/(m2

-d). 9 At any MSW landfill where C&D waste was used as 

daily cover or was comingled with the MSW, it is recommended that direct H2S measurements be used to 

develop specific H2S emissions for the landfill. 

The rate of emissions from a landfill is governed by gas production and transport mechanisms. 

Production mechanisms involve the production of the emission constituent in its vapor phase through 

vaporization, biological decomposition, or chemical reaction. Transport mechanisms involve the 

transportation of a volatile constituent in its vapor phase to the surface of the landfill, through the air 

boundary layer above the landfill, and into the atmosphere. The three major transport mechanisms that 

enable transport of a volatile constituent in its vapor phase are diffusion, convection, and displacement. 

75
 
 

 

Although relatively uncommon, fires can occur on the surface of the landfill or underground. The 

smoke from a landfill fire frequently contains many dangerous chemical compounds, including: carbon 

monoxide, particulate matter and hazardous gases that are the products of incomplete combustion, and 

very elevated concentrations of the many gaseous constituents normally occurring in LFG. Of particular 

concern in landfill fires is the emission of dioxins/furans. Accidental fires at landfills and the 

uncontrolled burning of residential waste are considered the largest sources of dioxin emissions in the 

United States.10 The composition of the gases from landfill fires is highly variable and dependent on 

numerous site specific factors, including: the composition of the material burning, the composition of the 

surrounding waste, the temperature of the burning waste, and the presence of oxygen. The only reliable 

method for estimating the emissions from a landfill fire involves testing the emissions directly. More 

information is available on landfill fires and their emissions from reference 11. 

2.4.4.1 Uncontrolled Emissions — Several methods have been developed by EPA to determine the 

uncontrolled emissions of the various compounds present in LFG. The newest measurement method is 

optical remote sensing with radial plume mapping (ORS-RPM). This method uses an optical emission 

detector such as open-path Fourier transform infrared spectroscopy (FTIR), ultraviolet differential 

absorption spectroscopy (UV-DOAS), or open-path tunable diode laser absorption spectroscopy (OPTDLAS); coupled with radial plume mapping software that processes path-integrated emission 

concentration data and meteorological data to yield an estimate of uncontrolled emissions. More 

information on this newest method is described in Evaluation of Fugitive Emissions Using Ground-Based 

Optical Remote Sensing Technology (EPA/600/R-07/032).12 Additional research is ongoing to provide 

additional guidance on the use of optical remote sensing for application at landfills. Evaluating 

uncontrolled emissions from landfills can be a challenge. This is due to the changing nature of landfills, 

scale and complexity of the site, topography, and spatial and temporal variability in emissions. 

Additional guidance is being developed for application of EPA’s test method for area sources emissions. 

This is expected to be released by the spring of 2009. For more information, refer to the Emission 

Measurement Center of EPA’s Technology Transfer Network 

(http://www.epa.gov/ttn/emc/tmethods.html). Additional information on ORS technology can also be 

found on EPA’s website for Measurement and Monitoring Technologies for 21st Century (21M2

) which 

provided funding to identify improved technologies for quantifying area source emissions 

(http://www.clu-in.org/programs/21m2/openpath/). 

Often flux data are used to evaluate LFG collection efficiency. The concern with the use of this data is 

that it does not capture emission losses from header pipes or extraction wells. The other concern is that 

depending upon the design of the study, the emission variability across a landfill surface is not captured. 

Emission losses can occur from cracks and fissures or difference in landfill cover material. Often, 

alternative cover material is used to help promote infiltration, particularly for wet landfill operation. This 

can result in larger loss of fugitive emissions. Another loss of landfill gas is through the leachate 

collection pumps and wells. For many of these potential losses, a flux box is not considered adequate to 

capture the total loss of fugitive gas. The use of ORS technology is considered more reliable. 

When direct measurement data are not available, the most commonly used EPA method to 

estimate the uncontrolled emissions associated with LFG is based on a biological decay model. In this 

method, the generation of CH4 must first be estimated by using a theoretical first-order kinetic model of 

CH4 production developed by the EPA13: 

−kc −kt QCH4 

=1.3Lo R (e − e ) (1) 

where: 

QCH4 = Methane generation rate at time t, m3

/yr; 

76
 
 

 

 

 

Lo = Methane generation potential, m3 CH4/Mg of “wet” or “as received” refuse; 

R = Average annual refuse acceptance rate during active life, Mg of “wet” or “as received” 

refuse /yr; 

e = Base log, unitless; 

k = Methane generation rate constant, yr-1; 

c = Time since landfill closure, yrs (c = 0 for active landfills); and 

t = Time since the initial refuse placement, yrs. 

When annual refuse acceptance data is available, the following form of Equation (1) is used. This 

is the general form of the equation that is used in EPA’s Landfill Gas Emissions Model (LandGEM). Due 

to the complexity of the double summation, Equation (1alt) is normally implemented within a computer 

model. Equation (1 alt.) is more accurate because it accounts for the varying annual refuse flows and it 

calculates each year’s gas flow in 1

/10th year increments. 

n 1 Ri −ktij QCH4 = 1.3∑ ∑ k Lo e (1 alternate) 10 

i=1 j=0.1 

where: 

= Methane generation rate at time t, m3 Q /yr; CH4 

Lo = Methane generation potential, m3

 CH4/Mg of “wet” or “as received” refuse; 

Ri = Annual refuse acceptance rate for year i, Mg of “wet” or “as received” refuse /yr; 

e = Base log, unitless; 

k = Methane generation rate constant, yr-1; 

c = Time since landfill closure, yrs (c = 0 for active landfills); and 

t = Time since the initial refuse placement, yrs. 

i = year in life of the landfill 

j = 1

/10th year increment in the calculation. 

It should be noted that Equation (1) is provided for estimating CH4 emissions to the atmosphere. 

Other fates may exist for the gas generated in a landfill, including capture and subsequent microbial 

degradation within the landfill’s surface layer. Currently, there are no data that adequately address this 

fate. It is generally accepted that the bulk of the CH4 generated will be emitted through cracks or other 

openings in the landfill surface and that Equation (1) can be used to approximate CH4 emissions from an 

uncontrolled landfill. It should also be noted that Equation (1) is different from the equation used in other 

models such as LandGEM by the addition of the constant 1.3 at the front of the equation. This constant is 

included to compensate for LO which is typically determined by the amount of gas collected by LFG 

collection systems. The design of these systems will typically result in a gas capture efficiency of only 

75%. Therefore, 25% of the gas generated by the landfill is not captured and included in the development 

of LO. The ratio of total gas to captured gas is a ratio of 100/75 or equivalent to 1.3. 

Site-specific landfill information is generally available for variables R, c, and t. When refuse 

acceptance rate information is scant or unknown, R can be determined by dividing the refuse in place by 

the age of the landfill. If a facility has documentation that a certain segment (cell) of a landfill received 

only nondegradable refuse, then the waste from this segment of the landfill can be excluded from the 

calculation of R. Nondegradable refuse includes concrete, brick, stone, glass, plaster, wallboard, piping, 

plastics, and metal objects. The average annual acceptance rate should only be estimated by this method 

when there is inadequate information available on the actual average acceptance rate. The time variable, 

t, includes the total number of years that the refuse has been in place (including the number of years that 

the landfill has accepted waste and, if applicable, has been closed). 

77
 
 

Values for variables Lo and k are normally estimated. Estimation of the potential CH4 generation 

capacity of refuse (Lo) is generally treated as a function of the moisture and organic content of the refuse. 

Estimation of the CH4 generation constant (k) is a function of a variety of factors, including moisture, pH, 

temperature, and other environmental factors, and landfill operating conditions. 

Recommended AP-42 defaults for k are: 

k Value Landfill Conditions 

0.02 Areas receiving <25 inches/yr rainfall 

0.04 Areas receiving >25 inches/yr rainfall 

0.3 Wet landfills14 

For the purpose of the above table, wet landfills are defined as landfills which add large amounts of water 

to the waste. This added water may be recycled landfill leachates and condensates, or may be other 

sources of water such as treated wastewater. 

The CH4 generation potential, Lo, has been observed to vary from 6 to 270 m3

/Mg (200 to 8670 

ft3/ton), depending on the organic content of the waste material. A higher organic content results in a 

higher Lo. Food, textiles, paper, wood, and horticultural waste have the highest Lo value on a dry basis, 

while inert materials such as glass, metal and plastic have no Lo value.2

 Since moisture does not 

contribute to the value of Lo, a high moisture content waste, such as food or organic sludge, will have a 

lower Lo on an “as received” basis. When using Equation 1 to estimate emissions for typical MSW 

landfills in the U.S., a mean Lo value of 100 m3

/Mg refuse (3,530 ft3 /ton, “as received” basis) is 

recommended. 

There is a significant level of uncertainty in Equation 2 and its recommended defaults values for k 

and Lo. The recommended defaults k and Lo for conventional landfills, based upon the best fit to 40 

different landfills, yielded predicted CH4 emissions that ranged from ~30 to 400% of measured values and 

had a relative standard deviation of 0.73 (Table 2-2). The default values for wet landfills were based on a 

more limited set of data and are expected to contain even greater uncertainty. 

When gas generation reaches steady state conditions, LFG consists of approximately equal 

volumes of CO2 and CH4. LFG also typically contains as much as five percent N2 and other gases, and 

trace amounts of NMOCs. Since the flow of CO2 is approximately equal to the flow of CH4, the estimate 

derived for CH4 generation using Equation (1) can also be used to estimate CO2 generation. Addition of 

the CH4 and CO2 emissions will yield an estimate of total LFG emissions. If site-specific information is 

available on the actual CH4 and CO2 contents of the LFG, then the site-specific information should be 

used. 

Most of the NMOC emissions from landfills result from the volatilization of organic compounds 

contained in the landfilled waste. Small amounts may also be created by biological processes and 

chemical reactions within the landfill. Available data show that the range of values for total NMOC in 

LFG is from 31 ppmv to over 5,387 ppmv, and averages 838 ppmv. The proposed regulatory default of 

4,000 ppmv for NMOC concentration was developed for regulatory compliance purposes and is 

considered more conservative. For emissions inventory purposes, site-specific information should be 

taken into account when determining the total NMOC concentration, whenever available. Measured 

pollutant concentrations (i.e., as measured by EPA Reference Method 25C), must be corrected for air 

infiltration which can occur by two different mechanisms: LFG sample dilution and air intrusion into the 

landfill. These corrections require site-specific data for the LFG CH4, CO2, N2, and O2 content. If the 

ratio of N2 to O2 is less than or equal to 4.0 (as found in ambient air), then the total pollutant concentration 

78
 
 

 

 

 

 

 

 

 

 

 

 

 

 

is adjusted for sample dilution by assuming that CO2 and CH2 are the primary constituents of LFG 

(assumed to account for 100% of the LGF), and the following equation is used: 

C x (1x106) CP (correctedfor air infiltration) = P	 (2) C CO2 + CCH4 

where: 

CP = Concentration of pollutant P in LFG (i.e., NMOC as hexane), ppmv; 

C = CO2 concentration in LFG, ppmv; CO2

Q = CH4 Concentration in LFG, ppmv; and CH4 

1 x 106 = Constant used to correct concentration of P to units of ppmv. 

If the ratio of N2 to O2 concentrations (i.e., CN2, CO2) is greater than 4.0, then the total pollutant 

concentration should be adjusted for air intrusion into the landfill by using Equation (2) and adding the 

concentration of N2 (i.e., CN2) to the denominator. Values for CCO2, CCH4, CN2, CO2, can usually be found 

in the source test report for the particular landfill along with the total pollutant concentration data. 

To estimate uncontrolled emissions of NMOC or other LFG constituents, the following equation 

should be used: 

Q CH4 x CP QP = 6	 (3) CCH x (1x10 ) 4 

where: 

QP	 = Emission rate of pollutant P (i.e., NMOC), m3

/yr; 

QCH4

 = CH4 generation rate, m3/yr (from Equation 1); 

CP	 = Concentration of pollutant P in LFG, ppmv; and 

C = Concentration of CH4 in the LFG (assumed to be 50% expressed as 0.5) CH4 

Uncontrolled mass emissions per year of total NMOC (as hexane) and speciated organic and 

inorganic compounds can be estimated by the following equation: 

MWP x1 atm

UMP = QP x	 (4) −5 3 o (8.205x10 m − atm/gmol − K) x (1000g/kg) x (273+ T)

where: 

UMP	 = Uncontrolled mass emissions of pollutant P (i.e., NMOC), kg/yr; 

MWP	 = Molecular weight of P, g/gmol (i.e., 86.18 for NMOC as hexane); 

QP	 = Emission rate of pollutant P, m3

/yr; and 

T = Temperature of LFG, o

C. 

This equation assumes that the operating pressure of the system is approximately 1 atmosphere. 

If the temperature of the LFG is not known, a temperature of 25 o

C (77 oF) is recommended. 

Uncontrolled default concentrations of VOC, NMOC and speciated compounds are presented in 

Table 2.4-1 for landfills having a majority of the waste in place on or after 1992 and in Table 2.4-2 for 

landfills having a majority of the waste in place before 1992. These default concentrations have already 

been corrected for air infiltration and can be used as input parameters to Equation (3) for estimating 

79
 
 

 

 

emissions from landfills when site-specific data are not available. An analysis of the data, based on the 

co-disposal history (with non-residential wastes) of the individual landfills from which the concentration 

data were derived, indicates that for benzene, NMOC, and toluene, there is a difference in the 

uncontrolled concentrations. 

It is important to note that the compounds listed in Tables 2.4-1 and 2.4-2 are not the only 

compounds likely to be present in LFG. The listed compounds are those that were identified through a 

review of the available landfill test reports. The reader should be aware that additional compounds are 

likely present, such as those associated with consumer or industrial products. Given this information, 

extreme caution should be exercised in the use of the default emission concentrations given in Tables 2.4­

1 and 2.4-2. Available data have shown that there is a range of over two orders of magnitude in many of 

the pollutant concentrations among gases from various MSW landfills. 

2.4.4.2 Controlled Emissions — Emissions from landfills are typically controlled by installing a gas 

collection system, and either combusting the collected gas through the use of internal combustion engines, 

flares, or turbines, or by purifying the gas for direct use in place of a fuel such as natural gas. Gas 

collection systems are not 100% efficient in collecting LFG, so emissions of CH4 and NMOC at a landfill 

with a gas recovery system still occur. To estimate controlled emissions of CH4, NMOC, and other 

constituents in LFG, the collection efficiency of the system must first be estimated. Reported collection 

efficiencies typically range from 50 to 95%, with a default efficiency of 75% recommended by EPA for 

inventory purposes. The lower collection efficiencies are experienced at landfills with a large number of 

open cells, no liners, shallow soil covers, poor collection system and cap maintenance programs and/or a 

large number of cells without gas collection. The higher collection efficiencies may be achieved at closed 

sites employing good liners, extensive geomembrane-clay composite caps in conjunction with well 

engineered gas collection systems, and aggressive operation and maintenance of the cap and collection 

system. If documented site-specific collection efficiencies are available (i.e., through a comprehensive 

surface sampling program), then they may be used instead of the 75% average. An analysis showing a 

range in the gas collection system taking into account delays from gas collection from initial waste 

placement is provided in Section 2.0. 

Estimates of controlled emissions may also need to account for the control efficiency of the 

control device. Control efficiencies for NMOC and VOC based on test data for the combustion of LFG 

with differing control devices are presented in Table 2.4-3. As noted in the table, these control 

efficiencies may also be applied to other LFG constituents. Emissions from the control devices need to be 

added to the uncollected emissions to estimate total controlled emissions. 

 Controlled CH4, NMOC, VOC, and speciated emissions can be determined by either of two 

methods developed by EPA. The newest method is the optical remote sensing with radial plume mapping 

(ORS-RPM). This method uses an optical emission detector such as open-path Fourier transform infrared 

spectroscopy (FTIR), ultraviolet differential absorption spectroscopy (UV-DOAS), or open-path tunable 

diode laser absorption spectroscopy (OP-TDLAS); coupled with radial plume mapping software that 

processes path-integrated emission concentration data and meteorological data to yield an estimate of 

uncontrolled emissions. More information on this newest method is described in Evaluation of Fugitive 

Emissions Using Ground-Based Optical Remote Sensing Technology (EPA/600/R-07/032).12 

Historically, controlled emissions have been calculated with Equation 5. In this equation it is 

assumed that the LFG collection and control system operates 100 percent of the time. Minor durations of 

system downtime associated with routine maintenance and repair (i.e., 5 to 7 percent) will not appreciably 

effect emission estimates. The first term in Equation 5 accounts for emissions from uncollected LFG, 

while the second term accounts for emissions of the pollutant that were collected but not fully combusted 

in the control or utilization device: 

80
 
 

 

 

 

 

 

 

 

 

 

 

CMP

⎡

UMP x 

⎛

⎜

⎝

1− ηcol 

100 

⎞

⎟

⎠

⎤ ⎡

+
 UMP x 

ηcol x 

100
 

⎛

⎜

⎝

1 − ηcnt 

100 

⎞

⎟

⎠

⎤ (5) ⎢

⎣

= ⎥

⎦ ⎢

⎣ ⎥

⎦

where: 

CMP = Controlled mass emissions of pollutant P, kg/yr; 

UMP = Uncontrolled mass emissions of P, kg/yr (from Equation 4); 

ηcol = Efficiency of the LFG collection system, % (recommended default is 75%); and 

ηcnt = Efficiency of the LFG control or utilization device, %. 

Emission factors for the secondary compounds, CO, PM, NOx and dioxins/furans exiting the 

control device are presented in Table 2.4-4. These emission factors should be used when equipment 

vendor emission guarantees are not available. 

Controlled emissions of CO2 and sulfur dioxide (SO2) are best estimated using site-specific LFG 

constituent concentrations and mass balance methods.15 If site-specific data are not available, the data in 

Tables 2.4-1 and 2.4-2 can be used with the mass balance methods that follow. 

 Controlled CO2 emissions include emissions from the CO2 component of LFG and additional CO2 

formed during the combustion of LFG. The bulk of the CO2 formed during LFG combustion comes from 

the combustion of the CH4 fraction. Small quantities will be formed during the combustion of the NMOC 

fraction. However, this typically amounts to less than 1 percent of total CO2 emissions by weight. Also, 

the formation of CO through incomplete combustion of LFG will result in small quantities of CO2 not 

being formed. This contribution to the overall mass balance picture is also very small and does not have a 

significant impact on overall CO2 emissions.15 

The following equation which assumes a 100% combustion efficiency for CH4 can be used to 

estimate CO2 emissions from controlled landfills: 

⎛ ηcol ⎜

⎝

⎞

⎟

⎠ CM = UM
 + UM
 x x 2.75 (6) CO 2 CO 2 CH 4 100
 

where: 

CMCO2 = Controlled mass emissions of CO2, kg/yr; 

UMCO2 = Uncontrolled mass emissions of CO2, kg/yr (from Equation 4); 

UMCH4 = Uncontrolled mass emissions of CH4, kg/yr (from Equation 4); 

ηcol = Efficiency of the LFG collection system, % (recommended default is 75%); 

and 

2.75 = Ratio of the molecular weight of CO2 to the molecular weight of CH4. 

To prepare estimates of SO2 emissions, data on the concentration of reduced sulfur compounds 

within the LFG are needed. The best way to prepare this estimate is with site-specific information on the 

total reduced sulfur content of the LFG. Often these data are expressed in ppmv as sulfur (S). Equations 

3 and 4 should be used first to determine the uncontrolled mass emission rate of reduced sulfur 

compounds as sulfur. Then, the following equation can be used to estimate SO2 emissions: 

ηcol CM = UM
 x x 2.0 (7) SO2 S 100 

81 
 

 

 

 

 

 

 

 

 

 

 

If no site-specific data are available, values of 47 and 33 ppmv can be used for CS in the gas from 

landfills having a majority of the waste in place before 1992 and from landfills having a majority of the 

waste in place after 1992, respectively. These values were obtained by using the default concentrations 

presented in Tables 2.4-1 and 2.4-2 for reduced sulfur compounds and Equation 8. 

where: 

CMSO2 = Controlled mass emissions of SO2, kg/yr; 

UMS = Uncontrolled emissions of reduced sulfur compounds as sulfur, kg/yr (from 

Equations 3 and 4); 

ηcol = Efficiency of the LFG collection system, %; and 

2.0 = Ratio of the molecular weight of SO2 to the molecular weight of S. 

The next best method to estimate SO2 concentrations, if site-specific data for total reduced sulfur 

compounds as sulfur are not available, is to use site-specific data for speciated reduced sulfur compound 

concentrations. These data can be converted to ppmv as S with Equation 8. After the total reduced sulfur 

as S has been obtained from Equation 8, then Equations 3, 4, and 7 can be used to derive SO2 emissions. 

n 

i 1

where: 

CS = Concentration of total reduced sulfur compounds, ppmv as S (for use in Equation 3); 

(i.e., 1 for sulfides, 2 for disulfides); and 

∑= 

C = Concentration of each reduced sulfur compound, ppmv; P 

S = Number of moles of S produced from the combustion of each reduced sulfur compound P 

n = Number of reduced sulfur compounds available for summation. 

chlorinated compound in the LFG will be represented in the site test report (i.e., only those that the 

analytical method specifies). If these data are not available, then total chloride can be estimated from data 

∑= 

Hydrochloric acid [Hydrogen Chloride (HCl)] emissions are formed when chlorinated 

compounds in LFG are combusted in control equipment. The best methods to estimate HCl emissions are 

mass balance methods that are analogous to those presented above for estimating SO2 emissions. Hence, 

the best source of data to estimate HCl emissions is site-specific LFG data on total chloride [expressed in 

ppmv as the chloride ion (Cl-

)]. However, emission estimates may be underestimated, since not every 

on individual chlorinated species using Equation 9 below. 

n 

i 1 

C = C x S (8) 
 S P P

C =
 C x Cl (9) 
 Cl P P

where: 

CCl = Concentration of total chloride, ppmv as Cl­

 (for use in Equation 3);

CP = Concentration of each chlorinated compound, ppmv; 

ClP = Number of moles of Cl­

 produced from the combustion of each mole of chlorinated 

compound (i.e., 3 for 1,1,1-trichloroethane); and

n = Number of chlorinated compounds available for summation.

After the total chloride concentration (CCl) has been estimated, Equations 3 and 4 should be used 

to determine the total uncontrolled mass emission rate of chlorinated compounds as chloride ion (UMCl). 

This value is then used in Equation 10, below, to derive HCl emission estimates: 

82
 
 

 

 

 

 

 

 

 

ηcol ηcnt CMHCl = UMC1 x x 1.03 x	 (10) 100 100

where: 

CM = Controlled mass emissions of HCl, kg/yr; HCl

UMCl = Uncontrolled mass emissions of chlorinated compounds as chloride, kg/yr (from 

Equations 3 and 4); 

ηcol = Efficiency of the LFG collection system, percent; 

1.03 = Ratio of the molecular weight of HCl to the molecular weight of Cl-

; and 

ηcnt = Control efficiency of the LFG control or utilization device, percent. 

In estimating HCl emissions, it is assumed that all of the chloride ion from the combustion of 

chlorinated LFG constituents is converted to HCl. If an estimate of the control efficiency, ηcnt, is not 

available, then the control efficiency for the equipment listed in Table 2.4-3 should be used. This 

assumption is recommended to assume that HCl emissions are not under-estimated. 

If site-specific data on total chloride or speciated chlorinated compounds are not available, then 

default values of 42 and 74 ppmv can be used for CCl in the gas from landfills having a majority of the 

waste in place before 1992 and from landfills having a majority of the waste in place after 1992, 

respectively. These values were derived from the default LFG constituent concentrations presented in 

Tables 2.4-1 and 2.4-2. As mentioned above, use of this default may produce underestimates of HCl 

emissions since it is based only on those compounds for which analyses have been performed. The 

constituents listed in Table 2.4-1 and 2.4-2 are likely not all of the chlorinated compounds present in 

LFG. 

The reader is referred to AP-42 Volume I, Sections 13.2.1 and 13.2.2 for information on 

estimating fugitive dust emissions from paved and unpaved roads, and to Section 13.2.3 for information 

on estimating fugitive dust emissions from heavy construction operations; and to AP-42 Volume II 

Section II-7 for estimating exhaust emissions from construction equipment. 

2.4.5 Updates Since the Fifth Edition 

The Fifth Edition was released in January 1995. The November 1998 revision includes major 

revisions of the text and recommended emission factors contained in the section. The most significant 

revisions to this section since publication in the Fifth Edition are summarized below. 

Χ	 The equations to calculate the CH4, CO2 and other constituents were simplified. 

Χ	 The default L0 and k were revised based upon an expanded base of gas generation data. 

Χ	 The default ratio of CO2 to CH4 was revised based upon averages observed in available source 

test reports. 

Χ	 The default concentrations of LFG constituents were revised based upon additional data. 

References 16-148 are the emission test reports from which data were obtained for this section. 

Χ	 Additional control efficiencies were included and existing efficiencies were revised based upon 

additional emission test data. 

83
 
 

 

Χ	 Revised and expanded the recommended emission factors for secondary compounds emitted from 

typical control devices. 

The current (i.e., 2008) update includes text revisions and additional discussion, as well as revised 

recommended emission factors contained within the section. The more significant revisions are 

summarized below: 

Χ	 Default concentrations of LFG constituents were developed for landfills with the majority of their 

waste in place on or after 1992 (proposal of RCRA Subtitle D). The LFG constituent list from 

the last update reflects data from landfills with waste in place prior to 1992, so Table 2.4-2 was 

renamed to reflect this. 

Χ	 Control efficiencies were updated to incorporate additional emission test data and the table was 

revised to show the NMOC and VOC control efficiencies. 

Χ	 Revised and expanded the recommended emission factors for secondary compounds emitted from 

typical control devices. 

Χ	 The description of modern landfills and statistics about waste disposition in the U.S. were 

updated with 2006 information. 

Χ	 EPA’s newest measurement method for determining landfill emissions, Optical Remote Sensing 

with Radial Plume Mapping (ORS-RPM), was added to the discussion of available options for 

measuring landfill emissions. 

Χ	 A factor of 1.3 was added to Equation (1) to account for the fact that L0 is typically determined by 

the amount of CH4 collected at landfills using equipment that typically has a capture efficiency of 

only 75%. 

Χ	 A k value of 0.3 was added to the list of recommended k values for use in Equation (1) to more 

accurately model landfill gas emissions from wet landfills. 

Table 2.4-1. DEFAULT CONCENTRATIONS FOR LFG CONSTITUENTS FOR LANDFILLS 

WITH WASTE IN PLACE ON OR AFTER 1992 

Compound CAS Number Molecular Weight 

Default 

Concentration 

(ppmv) 

Recommended 

Emission Factor 

Rating 

NMOC (as hexane)a 86.18 8.38E+02 A 

VOCb NA 8.35E+02 A 

1,1,1-Trichloroethanec

 71556 133.40 2.43E-01 A 

1,1,2,2-Tetrachloroethanec

 79345 167.85 5.35E-01 E 

1,1,2,3,4,4-Hexachloro-1,3-butadiene 

(Hexachlorobutadiene)c 87683 260.76 3.49E-03 D 

1,1,2-Trichloro-1,2,2-Trifluoroethane 

(Freon 113) 76131 187.37 6.72E-02 C 

1,1,2-Trichloroethanec

 79005 133.40 1.58E-01 D 

1,1-Dichloroethanec

 75343 98.96 2.08E+00 A 

1,1-Dichloroethene (1,1­

Dichloroethylene)c 75354 96.94 1.60E-01 A 

1,2,3-Trimethylbenzene 526738 120.19 3.59E-01 D 

1,2,4-Trichlorobenzenec

 120821 181.45 5.51E-03 C 

84
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1,2,4-Trimethylbenzene 95636 120.19 1.37E+00 B 

1,2-Dibromoethane (Ethylene 

dibromide)c 106934 187.86 4.80E-03 B 

1,2-Dichloro-1,1,2,2­

tetrafluoroethane (Freon 114) 76142 170.92 1.06E-01 B 

1,2-Dichloroethane (Ethylene 

dichloride)c 107062 98.96 1.59E-01 A 

1,2-Dichloroethene 540590 96.94 1.14E+01 E 

1,2-Dichloropropanec

 78875 112.99 5.20E-02 D 

1,2-Diethylbenzene 135013 134.22 1.99E-02 D 

1,3,5-Trimethylbenzene 108678 120.19 6.23E-01 C 

1,3-Butadiene (Vinyl ethylene)c

 106990 54.09 1.66E-01 C 

1,3-Diethylbenzene 141935 134.22 6.55E-02 D 

1,4-Diethylbenzene 105055 134.22 2.62E-01 D 

1,4-Dioxane (1,4-Diethylene 

dioxide)c 123911 88.11 8.29E-03 D 

1-Butene / 2-Methylbutene 106989 / 513359 56.11 / 70.13 1.22E+00 D 

1-Butene / 2-Methylpropene 106989 / 115117 56.11 1.10E+00 E 

1-Ethyl-4-methylbenzene (4-Ethyl 

toluene) 622968 120.19 9.89E-01 C 

1-Ethyl-4-methylbenzene (4-Ethyl 

toluene) + 1,3,5-Trimethylbenzene 622968 / 108678 120.19 5.79E-01 D 

1-Heptene 592767 98.19 6.25E-01 E 

1-Hexene / 2-Methyl-1-pentene 592416 / 763291 84.16 8.88E-02 D 

1-Methylcyclohexene 591491 96.17 2.27E-02 D 

1-Methylcyclopentene 693890 82.14 2.52E-02 D 

1-Pentene 109671 70.13 2.20E-01 D 

1-Propanethiol (n-Propyl mercaptan) 107039 76.16 1.25E-01 A 

2,2,3-Trimethylbutane 464062 100.20 9.19E-03 D 

2,2,4-Trimethylpentanec

 540841 114.23 6.14E-01 D 

2,2,5-Trimethylhexane 3522949 128.26 1.56E-01 D 

2,2-Dimethylbutane 75832 86.18 1.56E-01 D 

2,2-Dimethylpentane 590352 100.20 6.08E-02 D 

2,2-Dimethylpropane 463821 72.15 2.74E-02 E 

2,3,4-Trimethylpentane 565753 114.23 3.12E-01 D 

2,3-Dimethylbutane 79298 86.18 1.67E-01 D 

2,3-Dimethylpentane 565593 100.20 3.10E-01 D 

2,4-Dimethylhexane 589435 114.23 2.22E-01 D 

2,4-Dimethylpentane 108087 100.20 1.00E-01 D 

2,5-Dimethylhexane 592132 114.23 1.66E-01 D 

2,5-Dimethylthiophene 638028 112.19 6.44E-02 E 

2-Butanone (Methyl ethyl ketone)c

 78933 72.11 4.01E+00 C 

2-Ethyl-1-butene 760214 84.16 1.77E-02 D 

2-Ethylthiophene 872559 112.19 6.29E-02 E 

2-Ethyltoluene 611143 120.19 3.23E-01 D 

2-Hexanone (Methyl butyl ketone) 591786 100.16 6.13E-01 E 

2-Methyl-1-butene 563462 70.13 1.79E-01 D 

2-Methyl-1-propanethiol (Isobutyl 

mercaptan) 513440 90.19 1.70E-01 E 

2-Methyl-2-butene 513359 70.13 3.03E-01 D 

85
 
 

 

 

 

 

 

 

 

 

 

 

 

Table 2.4-1(CONTINUED). DEFAULT CONCENTRATIONS FOR LFG CONSTITUENTS FOR LANDFILLS 

WITH WASTE IN PLACE ON OR AFTER 1992 

Compound CAS Number Molecular Weight Default Concentration 

(ppmv) 

Recommended 

Emission Factor Rating 

2-Methyl-2-propanethiol (tertButylmercaptan) 75661 90.19 3.25E-01 E 

2-Methylbutane 78784 72.15 2.26E+00 D 

2-Methylheptane 592278 114.23 7.16E-01 D 

2-Methylhexane 591764 100.20 8.16E-01 D 

2-Methylpentane 107835 86.18 6.88E-01 D 

2-Propanol (Isopropyl alcohol) 67630 60.10 1.80E+00 C 

3,6-Dimethyloctane 15869940 142.28 7.85E-01 D 

3-Ethyltoluene 620144 120.19 7.80E-01 D 

3-Methyl-1-pentene 760203 84.16 6.99E-03 D 

3-Methylheptane 589811 114.23 7.63E-01 D 

3-Methylhexane 589344 100.20 1.13E+00 D 

3-Methylpentane 96140 86.18 7.40E-01 D 

3-Methylthiophene 616444 98.17 9.25E-02 E 

4-Methyl-1-pentene 691372 84.16 2.33E-02 E 

4-Methyl-2-pentanone (MIBK)c

 108101 100.16 8.83E-01 C 

4-Methylheptane 589537 114.23 2.49E-01 D 

Acetaldehydec

 75070 44.05 7.74E-02 D 

Acetone 67641 58.08 6.70E+00 C 

Acetonitrilec

 75058 41.05 5.56E-01 A 

Acrylonitrilec,d 107131 53.06 BDL 

Benzenec

 71432 78.11 2.40E+00 A 

Benzyl chloridec

 100447 126.58 1.81E-02 A 

Bromodichloromethane 75274 163.83 8.78E-03 E 

Bromomethane (Methyl bromide)c

 74839 94.94 2.10E-02 C 

Butane 106978 58.12 6.22E+00 C 

Carbon disulfidec

 75150 76.14 1.47E-01 A 

Carbon monoxide 630080 28.01 2.44E+01 C 

Carbon tetrachloridec

 56235 153.82 7.98E-03 A 

Carbon tetrafluoride (Freon 14) 75730 88.00 1.51E-01 E 

Carbonyl sulfide (Carbon oxysulfide)c 463581 60.08 1.22E-01 A 

Chlorobenzene 108907 112.56 4.84E-01 A 

Chlorodifluoromethane (Freon 22)c

 75456 86.47 7.96E-01 D 

Chloroethane (Ethyl chloride)c

 75003 64.51 3.95E+00 B 

Chloromethane (Methyl chloride)c

 74873 50.49 2.44E-01 B 

cis-1,2-Dichloroethene 156592 96.94 1.24E+00 B 

cis-1,2-Dimethylcyclohexane 2207014 112.21 8.10E-02 D 

cis-1,3-Dichloropropene 10061015 110.97 3.03E-03 D 

cis-1,3-Dimethylcyclohexane 638040 112.21 5.01E-01 D 

cis-1,4-Dimethylcyclohexane / trans1,3-Dimethylcyclohexane 624293 / 2207036 112.21 2.48E-01 D 

cis-2-Butene 590181 56.11 1.05E-01 D 

cis-2-Heptene 6443921 98.19 2.45E-02 E 

cis-2-Hexene 7688213 84.16 1.72E-02 D 

cis-2-Octene 7642048 112.21 2.20E-01 D 

cis-2-Pentene 627203 70.13 4.79E-02 D 

cis-3-Methyl-2-pentene 922623 84.16 1.79E-02 D 

Cyclohexane 110827 84.16 1.01E+00 B 

Cyclohexene 110838 82.14 1.84E-02 D 

86
 
 

 

 

 

 

 

 

 

 

 

 

Table 2.4-1(CONTINUED). DEFAULT CONCENTRATIONS FOR LFG CONSTITUENTS FOR LANDFILLS 

WITH WASTE IN PLACE ON OR AFTER 1992 

Compound CAS Number Molecular Weight Default Concentration 

(ppmv) 

Recommended 

Emission Factor Rating 

Cyclopentane 287923 70.13 2.21E-02 D 

Cyclopentene 142290 68.12 1.21E-02 D 

Decane 124185 142.28 3.80E+00 D 

Dibromochloromethane 124481 208.28 1.51E-02 D 

Dibromomethane (Methylene dibromide) 74953 173.84 8.35E-04 E 

Dichlorobenzenec,e 106467 147.00 9.40E-01 A 

Dichlorodifluoromethane (Freon 12) 75718 120.91 1.18E+00 B 

Dichloromethane (Methylene chloride)c 75092 84.93 6.15E+00 A 

Diethyl sulfide 352932 90.19 8.62E-02 E 

Dimethyl disulfide 624920 94.20 1.37E-01 A 

Dimethyl sulfide 75183 62.14 5.66E+00 A 

Dodecane (n-Dodecane) 112403 170.33 2.21E-01 D 

Ethane 74840 30.07 9.05E+00 D 

Ethanol 64175 46.07 2.30E-01 D 

Ethyl acetate 141786 88.11 1.88E+00 C 

Ethyl mercaptan (Ethanediol) 75081 62.14 1.98E-01 A 

Ethyl methyl sulfide 624895 76.16 3.67E-02 E 

Ethylbenzenec

 100414 106.17 4.86E+00 B 

Formaldehydec

 50000 30.03 1.17E-02 D 

Heptane 142825 100.20 1.34E+00 B 

Hexanec

 110543 86.18 3.10E+00 B 

Hydrogen sulfide 7783064 34.08 3.20E+01 A 

Indane (2,3-Dihydroindene) 496117 34.08 6.66E-02 D 

Isobutane (2-Methylpropane) 75285 58.12 8.16E+00 D 

Isobutylbenzene 538932 134.22 4.07E-02 D 

Isoprene (2-Methyl-1,3-butadiene) 78795 68.12 1.65E-02 D 

Isopropyl mercaptan 75332 76.16 1.75E-01 A 

Isopropylbenzene (Cumene)c

 98828 120.19 4.30E-01 D 

Mercury (total)c

 7439976 200.59 1.22E-04 B 

Mercury (elemental)c

 7439976 200.59 7.70E-05 C 

Mercury (monomethyl)c

 51176126 216.63 3.84E-07 C 

Mercury (dimethyl)c

 627441 258.71 2.53E-06 B 

Methanethiol (Methyl mercaptan) 74931 48.11 1.37E+00 A 

Methyl tert-butyl ether (MTBE)c

 1634044 88.15 1.18E-01 D 

Methylcyclohexane 108872 98.19 1.29E+00 D 

Methylcyclopentane 96377 84.16 6.50E-01 D 

Naphthalenec 91203 128.17 1.07E-01 D 

n-Butylbenzene 104518 134.22 6.80E-02 D 

Nonane 111842 128.26 2.37E+00 D 

n-Propylbenzene (Propylbenzene) 103651 120.19 4.13E-01 D 

Octane 111659 114.23 1.08E+00 D 

p-Cymene (1-Methyl-4­

lsopropylbenzene) 99876 134.22 3.58E+00 D 

Pentane 109660 72.15 4.46E+00 C 

Propane 74986 44.10 1.55E+01 C 

Propene 115071 42.08 3.32E+00 D 

Propyne 74997 40.06 3.80E-02 E 

sec-Butylbenzene 135988 134.22 6.75E-02 D 

87
 
 

 

 

 

 

Table 2.4-1(CONTINUED). DEFAULT CONCENTRATIONS FOR LFG CONSTITUENTS FOR LANDFILLS 

WITH WASTE IN PLACE ON OR AFTER 1992 

Compound CAS Number Molecular Weight 

Default 

Concentration 

(ppmv) 

Recommended 

Emission Factor 

Rating 

Styrene (Vinylbenzene)c

 100425 104.15 4.11E-01 B 

Tetrachloroethylene 

(Perchloroethylene)c 127184 165.83 2.03E+00 A 

Tetrahydrofuran (Diethylene oxide) 109999 72.11 9.69E-01 C 

Thiophene 110021 84.14 3.49E-01 E 

Toluene (Methyl benzene)c

 108883 92.14 2.95E+01 A 

trans-1,2-Dichloroethene 156605 96.94 2.87E-02 C 

trans-1,2-Dimethylcyclohexane 6876239 112.21 4.04E-01 D 

trans-1,3-Dichloropropene 10061026 110.97 9.43E-03 D 

trans-1,4-Dimethylcyclohexane 2207047 112.21 2.05E-01 D 

trans-2-Butene 624646 56.11 1.04E-01 D 

trans-2-Heptene 14686136 98.19 2.50E-03 E 

trans-2-Hexene 4050457 84.16 2.06E-02 D 

trans-2-Octene 13389429 112.21 2.41E-01 D 

trans-2-Pentene 646048 70.13 3.47E-02 D 

trans-3-Methyl-2-pentene 616126 84.16 1.55E-02 D 

Tribromomethane (Bromoform)c

 75252 252.73 1.24E-02 D 

Trichloroethylene (Trichloroethene)c

 79016 131.39 8.28E-01 A 

Trichlorofluoromethane (Freon 11) 91315616 137.37 2.48E-01 B 

Trichloromethane (Chloroform)c

 8013545 119.38 7.08E-02 A 

Undecane 1120214 156.31 1.67E+00 D 

Vinyl acetatec

 85306269 86.09 2.48E-01 C 

Vinyl chloride (Chloroethene)c

 75014 62.50 1.42E+00 A 

Xylenes (o-, m-, p-, mixtures) 8026093 106.17 9.23E+00 A 

NOTE: This is not an all-inclusive list of potential LFG constituents, only those for which test data were available 

at multiple sites. References 83-148. 

a

 For NSPS/Emission Guideline compliance purposes, the default concentration for NMOC as specified in the final 

rule must be used. 

b

 Calculated as 99.7% of NMOC, based on speciated emission test data. c

 Hazardous Air Pollutant listed in Title III of the 1990 Clean Air Act Amendments. d

 All tests below detection limit. Method detection limits are available for three tests, and are as follows: MDL = 2.00E-04, 

4.00E-03, and 2.00E-02 ppm
 e

 Many source tests did not indicate whether this compound was the ortho-, meta-, or para- isomer. The para isomer 

is a Title III listed HAP. 

Table 2.4-2. DEFAULT CONCENTRATIONS FOR LFG CONSTITUENTS FOR LANDFILLS WITH 

WASTE IN PLACE PRIOR TO 1992 (SCC 50100402, 50300603) 

Compound Molecular Weight 

 Default Concentration 

(ppmv) Emission Factor Rating 

NMOC (as hexane)e

 86.18 

Co-disposal (SCC 50300603) 2,420 D 

 No or Unknown co-disposal (SCC 50100402) 595 B 

1,1,1-Trichloroethane (methyl chloroform)a

 133.42 0.48 B 

1,1,2,2-Tetrachloroethanea 167.85 1.11 C 

1,1-Dichloroethane (ethylidene dichloride)a

 98.95 2.35 B 

1,1-Dichloroethene (vinylidene chloride)a

 96.94 0.20 B 

88
 
 

 

 

Table 2.4-2 (CONTINUED). DEFAULT CONCENTRATIONS FOR LFG CONSTITUENTS FOR 

LANDFILLS WITH WASTE IN PLACE PRIOR TO 1992 

(SCC 50100402, 50300603) 

Compound Molecular Weight 

Default Concentration 

(ppmv) 

Emission Factor 

Rating 

1,2-Dichloroethane (ethylene dichloride)a

 98.96 0.41 B 

1,2-Dichloropropane (propylene dichloride)a

 112.98 0.18 D 

2-Propanol (isopropyl alcohol) 60.11 50.1 E 

Acetone 58.08 7.01 B 

Acrylonitrilea

 53.06 6.33 D 

Benzenea

 78.11 

 Co-disposal (SCC 50300603) 11.1 D

 No or Unknown co-disposal (SCC 50100402) 1.91 B 

Bromodichloromethane 163.83 3.13 C 

Butane 58.12 5.03 C 

Carbon disulfidea

 76.13 0.58 C 

Carbon monoxideb

 28.01 141 E 

Carbon tetrachloridea

 153.84 0.004 B 

Carbonyl sulfidea

 60.07 0.49 D 

Chlorobenzenea

 112.56 0.25 C 

Chlorodifluoromethane 86.47 1.30 C 

Chloroethane (ethyl chloride)a

 64.52 1.25 B 

Chloroforma

 119.39 0.03 B 

Chloromethane 50.49 1.21 B 

Dichlorobenzenec

 147 0.21 E 

Dichlorodifluoromethane 120.91 15.7 A 

Dichlorofluoromethane 102.92 2.62 D 

Dichloromethane (methylene chloride)a

 84.94 14.3 A 

Dimethyl sulfide (methyl sulfide) 62.13 7.82 C 

Ethane 30.07 889 C 

Ethanol 46.08 27.2 E 

Ethyl mercaptan (ethanethiol) 62.13 2.28 D 

Ethylbenzenea

 106.16 4.61 B 

Ethylene dibromide 187.88 0.001 E 

Fluorotrichloromethane 137.38 0.76 B 

Hexanea

 86.18 6.57 B 

Hydrogen sulfide 34.08 35.5 B 

Mercury (total)a,d 200.61 2.92x10-4 E 

Methyl ethyl ketonea 72.11 7.09 A 

Methyl isobutyl ketonea 100.16 1.87 B 

Methyl mercaptan 48.11 2.49 C 

89
 
 

 

 

 

 

 

Table 2.4-2 (CONTINUED). DEFAULT CONCENTRATIONS FOR LFG CONSTITUENTS FOR 

LANDFILLS WITH WASTE IN PLACE PRIOR TO 1992 (SCC 50100402, 50300603) 

Compound Molecular Weight 

Default Concentration 

(ppmv) 

Emission Factor 

Rating 

Pentane 72.15 3.29 C 

Perchloroethylene (tetrachloroethylene)a 165.83 3.73 B 

Propane 44.09 11.1 B 

t-1,2-dichloroethene 96.94 2.84 B 

Toluenea

 92.13 

 Co-disposal (SCC 50300603) 165 D

 No or Unknown co-disposal (SCC 50100402) 39.3 A 

Trichloroethylene (trichloroethene)a 131.38 2.82 B 

Vinyl chloridea 62.50 7.34 B 

Xylenesa 106.16 12.1 B 

NOTE: This is not an all-inclusive list of potential LFG constituents, only those for which test data were available 

at multiple sites. References 16-82. Source Classification Codes in parentheses. a

 Hazardous Air Pollutants listed in Title III of the 1990 Clean Air Act Amendments. 

b

 Carbon monoxide is not a typical constituent of LFG, but does exist in instances involving landfill (underground) 

combustion. Therefore, this default value should be used with caution. Of 18 sites where CO was measured, only 2 

showed detectable levels of CO. 

c

 Source tests did not indicate whether this compound was the para- or ortho- isomer. The para isomer is a Title IIIlisted HAP. 

d

 No data were available to speciate total Hg into the elemental and organic forms. e

 For NSPS/Emission Guideline compliance purposes, the default concentration for NMOC as specified in the final 

rule must be used. For purposes not associated with NSPS/Emission Guideline compliance, the default VOC 

content at co-disposal sites can be estimated by 85 percent by weight (2,060 ppmv as hexane); at No or Unknown
 

sites can be estimated by 39 percent by weight 235 ppmv as hexane).
 

Table 2.4-3. CONTROL EFFICIENCIES FOR LFG NMOC and VOCa 

Control Device 

Control Efficiency (%)b 

Typical Range Rating 

Boiler/Steam Turbine 

(50100423) 98.6 96-99+ D 

Flarec 

(50100410) 

(50300601) 

97.7 86-99+ A 

Gas Turbine 

(50100420) 94.4 92-97 E 

IC Engine 

(50100421) 97.2 95-99+ D 

a References 16-148. Source Classification Codes in parentheses. 

b

 Control efficiency may also be applied to LFG constituents in Tables 2-4.1 and 2.4-2, except for 

mercury. For any combustion equipment, the control efficiency for Hg should be assumed to be 0. 

c Where information on equipment was given in the reference, test data were taken from enclosed flares. 

Control efficiencies are assumed to be equally representative of open flares. 

90 
 

 

Table 2.4-4. EMISSION FACTORS FOR SECONDARY COMPOUNDS 

EXITING CONTROL DEVICESa
 

Control Device Pollutantb 

Typical Rate, 

kg/106

 dscm 

CH4 

Typical Rate, 

lb/106

 dscf CH4 

Emission Factor 

Rating 

Flarec 

(50100410) 

(50300601) 

Nitrogen dioxide 

Carbon monoxide 

Particulate matter 

Dioxin/Furan 

631 

737 

238 

6.7x10-6 

39 

46 

15 

4.2x10-7 

A 

A 

A 

E 

IC Engine 

(50100421) 

Nitrogen dioxide 

Carbon monoxide 

Particulate matter 

11,620 

8,462 

232 

725 

528 

15 

C 

C 

D 

Boiler/Steam Turbined 

(50100423) 

Nitrogen dioxide 

Carbon monoxide 

Particulate matter 

Dioxin/Furan 

677 

116 

41 

5.1x10-6 

42 

7 

3 

3.2x10-7 

D 

D 

D 

D 

Gas Turbine 

(50100420) 

Nitrogen dioxide 

Carbon monoxide 

Particulate matter 

1,400 

3,600 

350 

87 

230 

22 

D 

E 

E 

a

 Source Classification Codes in parentheses.
 b

 No data on PM size distributions were available, however for other gas-fired combustion sources, most of the 

particulate matter is less than 2.5 microns in diameter. Hence, this emission factor can be used to provide estimates 

of PM-10 or PM-2.5 emissions. See section 2.4.4.2 for methods to estimate CO2, SO2, and HCl.
 c Where information on equipment was given in the reference, test data were taken from enclosed flares. Control
 

efficiencies are assumed to be equally representative of open flares. d

 All source tests were conducted on boilers, however emission factors should also be representative of steam

turbines. Emission factors are representative of boilers equipped with low-NOx burners and flue gas recirculation. 

No data were available for uncontrolled NOx emissions. 

References for Section 2.4 

1.	 "Criteria for Municipal Solid Waste Landfills," 40 CFR Part 258, Volume 56, No. 196, October 9, 

1991. 

2.	 Air Emissions from Municipal Solid Waste Landfills - Background Information for Proposed 

Standards and Guidelines, Office of Air Quality Planning and Standards, EPA-450/3-90-011a, 

Chapters 3 and 4, U. S. Environmental Protection Agency, Research Triangle Park, NC, March 

1991. 

3.	 Municipal Solid Waste in the United States: 2006 Facts and Figures, Office of Solid Waste, 

U. S. Environmental Protection Agency, Washington, DC, December 2007. 

http://www.epa.gov/epaoswer/non-hw/muncpl/msw99.htm 

4.	 Eastern Research Group, Inc., List of Municipal Solid Waste Landfills, Prepared for the

U. S. Environmental Protection Agency, Office of Solid Waste, Municipal and Industrial Solid 

Waste Division, Washington, DC, September 1992. 

5.	 Suggested Control Measures for Landfill Gas Emissions, State of California Air Resources Board, 

Stationary Source Division, Sacramento, CA, August 1990. 

6.	 "Standards of Performance for New Stationary Sources and Guidelines for Control of Existing 

Sources: Municipal Solid Waste Landfills; Proposed Rule, Guideline, and Notice of Public 

Hearing," 40 CFR Parts 51, 52, and 60, Vol. 56, No. 104, May 30, 1991. 

91
 
7.	 U.S. DOE, National Renewable Energy Laboratory, Comparison of Models for Predicting Landfill 

Methane Recovery, March 1997, Available online: 

http://www.nrel.gov/docs/legosti/fy97/26041.pdf 

8.	 Eun, Sangho, Debra R. Reinhart, C. David Cooper, Timothy G. Townsend, Ayman Faour. 

Hydrogen sulfide flux measurements from construction and demolition debris (C&D) landfills. 

Waste Management 27 (2007) 220-227. Available online: http://www.sciencedirect.com 

9.	 Lee, Sue, Qiyong Xu, Matthew Booth, Timothy G. Townsend, Paul Chadik and Gabriel Bitton. 

Reduced sulfur compounds in gas from construction and demolition debris landfills. Department of

Environmental Engineering Sciences, University of Florida, P.O. Box 116450, Gainesville, FL 

32611-6450, United States. October 2005. Available online: http://www.sciencedirect.com 

10.	 Gullett, B.K., P.M. Lemieux, C.C. Lutes, C.K.. Winterrowd and D.L. Winters, 2001. Emissions of 

PCDD/F from uncontrolled, domestic waste burning , Chemosphere, Volume 43, Issues 4-7, May 

2001, Pages 721-725 

11.	 Landfill Fires, Their Magnitude, Characteristics, and Mitigation, prepared by TriData Corporation, 

1000 Wilson Boulevard Arlington, Virginia 22209, for Federal Emergency Management Agency,

United States Fire Administration, National Fire Data Center, May 2002, 

http://www.usfa.dhs.gov/downloads/pdf/publications/fa-225.pdf 

12.	 Evaluation of Fugitive Emissions Using Ground-Based Optical Remote Sensing Technology, Office 

of Research and Development, U. S. Environmental Protection Agency, Washington, DC, 

(EPA/600/R-07/032), February 2007. 

13.	 R.L. Peer, et al., Memorandum Methodology Used to Revise the Model Inputs in the Municipal 

Solid Waste Landfills Input Data Bases (Revised), to the Municipal Solid Waste Landfills Docket 

No. A-88-09, April 28, 1993. 

14.	 Debra R. Reinhart, Ayman A. Faour, and Huaxin You, First-Order Kinetic Gas Generation Model 

Parameters for Wet Landfills, U. S. Environmental Protection Agency, (EPA-600/R-05/072), June 

2005. 

15.	 Letter and attached documents from C. Nesbitt, Los Angeles County Sanitation Districts, to K. 

Brust, E.H. Pechan and Associates, Inc., December 6, 1996. 

16.	 A.R. Chowdhury, Emissions from a Landfill Gas-Fired Turbine/Generator Set, Source Test Report 

C-84-33, Los Angeles County Sanitation District, South Coast Air Quality Management District, 

June 28, 1984. 

17.	 Engineering-Science, Inc., Report of Stack Testing at County Sanitation District Los Angeles 

Puente Hills Landfill, Los Angeles County Sanitation District, August 15, 1984. 

18.	 J.R. Manker, Vinyl Chloride (and Other Organic Compounds) Content of Landfill Gas Vented to an 

Inoperative Flare, Source Test Report 84-496, David Price Company, South Coast Air Quality 

Management District, November 30, 1984. 

19.	 S. Mainoff, Landfill Gas Composition, Source Test Report 85-102, Bradley Pit Landfill, South 

Coast Air Quality Management District, May 22, 1985. 

20.	 J. Littman, Vinyl Chloride and Other Selected Compounds Present in A Landfill Gas Collection 

System Prior to and after Flaring, Source Test Report 85-369, Los Angeles County Sanitation 

District, South Coast Air Quality Management District, October 9, 1985. 

92
 
 

21.	 W.A. Nakagawa, Emissions from a Landfill Exhausting Through a Flare System, Source Test 

Report 85-461, Operating Industries, South Coast Air Quality Management District, October 14, 

1985. 

22.	 S. Marinoff, Emissions from a Landfill Gas Collection System, Source Test Report 85-511. 

Sheldon Street Landfill, South Coast Air Quality Management District, December 9, 1985. 

23.	 W.A. Nakagawa, Vinyl Chloride and Other Selected Compounds Present in a Landfill Gas 

Collection System Prior to and after Flaring, Source Test Report 85-592, Mission Canyon Landfill, 

Los Angeles County Sanitation District, South Coast Air Quality Management District, January 16, 

1986. 

24.	 California Air Resources Board, Evaluation Test on a Landfill Gas-Fired Flare at the BKK Landfill 

Facility, West Covina, CA, ARB-SS-87-09, July 1986. 

25.	 S. Marinoff, Gaseous Composition from a Landfill Gas Collection System and Flare, Source Test 

Report 86-0342, Syufy Enterprises, South Coast Air Quality Management District, 

August 21, 1986. 

26.	 Analytical Laboratory Report for Source Test, Azusa Land Reclamation, June 30, 1983, South 

Coast Air Quality Management District. 

27.	 J.R. Manker, Source Test Report C-84-202, Bradley Pit Landfill, South Coast Air Quality 

Management District, May 25, 1984. 

28.	 S. Marinoff, Source Test Report 84-315, Puente Hills Landfill, South Coast Air Quality

Management District, February 6, 1985. 

29.	 P.P. Chavez, Source Test Report 84-596, Bradley Pit Landfill, South Coast Air Quality 

Management District, March 11, 1985. 

30.	 S. Marinoff, Source Test Report 84-373, Los Angeles By-Products, South Coast air Quality 

Management District, March 27, 1985. 

31.	 J. Littman, Source Test Report 85-403, Palos Verdes Landfill, South Coast Air Quality

Management District, September 25, 1985. 

32.	 S. Marinoff, Source Test Report 86-0234, Pacific Lighting Energy Systems, South Coast Air 

Quality Management District, July 16, 1986. 

33.	 South Coast Air Quality Management District, Evaluation Test on a Landfill Gas-Fired Flare at the 

Los Angeles County Sanitation District's Puente Hills Landfill Facility, [ARB/SS-87-06], 

Sacramento, CA, July 1986. 

34.	 D.L. Campbell, et al., Analysis of Factors Affecting Methane Gas Recovery from Six Landfills, Air 

and Energy Engineering Research Laboratory, EPA-600/2-91-055, U. S. Environmental Protection 

Agency, Research Triangle Park, NC, September 1991. 

35.	 Browning-Ferris Industries, Source Test Report, Lyon Development Landfill, August 21, 1990. 

36.	 X.V. Via, Source Test Report, Browning-Ferris Industries, Azusa Landfill. 

37.	 M. Nourot, Gaseous Composition from a Landfill Gas Collection System and Flare Outlet. 

Laidlaw Gas Recovery Systems, to J.R. Farmer, OAQPS:ESD, December 8, 1987. 

38.	 D.A. Stringham and W.H. Wolfe, Waste Management of North America, Inc., to J.R. Farmer, 

OAQPS:ESD, January 29, 1988, Response to Section 114 questionnaire. 

93
 
 

 

 

 

39.	 V. Espinosa, Source Test Report 87-0318, Los Angeles County Sanitation District Calabasas 

Landfill, South Coast Air Quality Management District, December 16, 1987. 

40.	 C.S. Bhatt, Source Test Report 87-0329, Los Angeles County Sanitation District, Scholl Canyon 

Landfill, South Coast Air Quality Management District, December 4, 1987. 

41.	 V. Espinosa, Source Test Report 87-0391, Puente Hills Landfill, South Coast Air Quality 

Management District, February 5, 1988. 

42.	 V. Espinosa, Source Test Report 87-0376, Palos Verdes Landfill, South Coast Air Quality 

Management District, February 9, 1987. 

43.	 Bay Area Air Quality Management District, Landfill Gas Characterization, Oakland, CA, 1988. 

44.	 Steiner Environmental, Inc., Emission Testing at BFI's Arbor Hills Landfill, Northville, Michigan, 

September 22 through 25, 1992, Bakersfield, CA, December 1992. 

45.	 PEI Associates, Inc., Emission Test Report - Performance Evaluation Landfill-Gas Enclosed Flare, 

Browning Ferris Industries, Chicopee, MA, 1990. 

46.	 Kleinfelder Inc., Source Test Report Boiler and Flare Systems, Prepared for Laidlaw Gas Recovery 

Systems, Coyote Canyon Landfill, Diamond Bar, CA, 1991. 

47.	 Bay Area Air Quality Management District, McGill Flare Destruction Efficiency Test Report for 

Landfill Gas at the Durham Road Landfill, Oakland, CA, 1988. 

48.	 San Diego Air Pollution Control District, Solid Waste Assessment for Otay Valley/Annex Landfill. 

San Diego, CA, December 1988. 

49.	 PEI Associates, Inc., Emission Test Report - Performance Evaluation Landfill Gas Enclosed Flare, 

Rockingham, VT, September 1990. 

50.	 Browning-Ferris Industries, Gas Flare Emissions Source Test for Sunshine Canyon Landfill. 

Sylmar, CA, 1991. 

51.	 Scott Environmental Technology, Methane and Nonmethane Organic Destruction Efficiency Tests 

of an Enclosed Landfill Gas Flare, April 1992. 

52.	 BCM Engineers, Planners, Scientists and Laboratory Services, Air Pollution Emission Evaluation 

Report for Ground Flare at Browning Ferris Industries Greentree Landfill, Kersey, Pennsylvania. 

Pittsburgh, PA, May 1992. 

53.	 EnvironMETeo Services Inc., Stack Emissions Test Report for Ameron Kapaa Quarry, Waipahu,

HI, January 1994. 

54.	 Waukesha Pearce Industries, Inc., Report of Emission Levels and Fuel Economies for Eight 

Waukesha 12V-AT25GL Units Located at the Johnston, Rhode Island Central Landfill, Houston 

TX, July 19, 1991. 

55.	 Mostardi-Platt Associates, Inc., Gaseous Emission Study Performed for Waste Management of

North America, Inc., CID Environmental Complex Gas Recovery Facility, August 8, 1989.

Chicago, IL, August 1989. 

56.	 Mostardi-Platt Associates, Inc., Gaseous Emission Study Performed for Waste Management of

North America, Inc., at the CID Environmental Complex Gas Recovery Facility, July 12-14, 1989. 

Chicago, IL, July 1989. 

94
 
 

 

57.	 Browning-Ferris Gas Services, Inc., Final Report for Emissions Compliance Testing of One 

Waukesha Engine Generator, Chicopee, MA, February 1994. 

58.	 Browning-Ferris Gas Services, Inc., Final Report for Emissions Compliance Testing of Three 

Waukesha Engine Generators, Richmond, VA, February 1994. 

59.	 South Coast Environmental Company (SCEC), Emission Factors for Landfill Gas Flares at the 

Arizona Street Landfill, Prepared for the San Diego Air Pollution Control District, San Diego, CA, 

November 1992. 

60.	 Carnot, Emission Tests on the Puente Hills Energy from Landfill Gas (PERG) Facility - Unit 400, 

September 1993, Prepared for County Sanitation Districts of Los Angeles County, Tustin, CA, 

November 1993. 

61.	 Pape & Steiner Environmental Services, Compliance Testing for Spadra Landfill Gas-to-Energy 

Plant, July 25 and 26, 1990, Bakersfield, CA, November 1990. 

62.	 AB2588 Source Test Report for Oxnard Landfill, July 23-27, 1990, by Petro Chem Environmental 

Services, Inc., for Pacific Energy Systems, Commerce, CA, October 1990. 

63.	 AB2588 Source Test Report for Oxnard Landfill, October 16, 1990, by Petro Chem Environmental 

Services, Inc., for Pacific Energy Systems, Commerce, CA, November 1990. 

64.	 Engineering Source Test Report for Oxnard Landfill, December 20, 1990, by Petro Chem

Environmental Services, Inc., for Pacific Energy Systems, Commerce, CA, January 1991. 

65.	 AB2588 Emissions Inventory Report for the Salinas Crazy Horse Canyon Landfill, Pacific Energy, 

Commerce, CA, October 1990. 

66.	 Newby Island Plant 2 Site IC Engine's Emission Test, February 7-8, 1990, Laidlaw Gas Recovery

Systems, Newark, CA, February 1990. 

67.	 Landfill Methane Recovery Part II: Gas Characterization, Final Report, Gas Research Institute, 

December 1982. 

68.	 Letter from J.D. Thornton, Minnesota Pollution Control Agency, to R. Myers, U.S. EPA, February

1, 1996. 

69.	 Letter and attached documents from M. Sauers, GSF Energy, to S. Thorneloe, U.S. EPA, May 29, 

1996. 

70.	 Landfill Gas Particulate and Metals Concentration and Flow Rate, Mountaingate Landfill Gas 

Recovery Plant, Horizon Air Measurement Services, prepared for GSF Energy, Inc., May 1992. 

71.	 Landfill Gas Engine Exhaust Emissions Test Report in Support of Modification to Existing IC

Engine Permit at Bakersfield Landfill Unit #1, Pacific Energy Services, December 4, 1990. 

72.	 Addendum to Source Test Report for Superior Engine #1 at Otay Landfill, Pacific Energy Services, 

April 2, 1991. 

73.	 Source Test Report 88-0075 of Emissions from an Internal Combustion Engine Fueled by Landfill 

Gas, Penrose Landfill, Pacific Energy Lighting Systems, South Coast Air Quality Management 

District, February 24, 1988. 

74.	 Source Test Report 88-0096 of Emissions from an Internal Combustion Engine Fueled by Landfill 

Gas, Toyon Canyon Landfill, Pacific Energy Lighting Systems, March 8, 1988. 

95
 
75.	 Determination of Landfill Gas Composition and Pollutant Emission Rates at Fresh Kills Landfill, 

revised Final Report, Radian Corporation, prepared for U.S. EPA, November 10, 1995. 

76.	 Advanced Technology Systems, Inc., Report on Determination of Enclosed Landfill Gas Flare 

Performance, Prepared for Y & S Maintenance, Inc., February 1995. 

77.	 Chester Environmental, Report on Ground Flare Emissions Test Results, Prepared for Seneca 

Landfill, Inc., October 1993. 

78.	 Smith Environmental Technologies Corporation, Compliance Emission Determination of the 

Enclosed Landfill Gas Flare and Leachate Treatment Process Vents, Prepared for Clinton County

Solid Waste Authority, April 1996. 

79.	 AirRecon®, Division of RECON Environmental Corp., Compliance Stack Test Report for the 

Landfill Gas FLare Inlet & Outlet at Bethlehem Landfill, Prepared for LFG Specialties Inc.,

December 3, 1996. 

80.	 ROJAC Environmental Services, Inc., Compliance Test Report, Hartford Landfill Flare Emissions 

Test Program, November 19, 1993. 

81.	 Normandeau Associates, Inc., Emissions Testing of a Landfill Gas Flare at Contra Costa Landfill, 

Antioch, California, March 22, 1994 and April 22, 1994, May 17, 1994. 

82.	 Roe, S.M., et. al., Methodologies for Quantifying Pollution Prevention Benefits from Landfill Gas 

Control and Utilization, Prepared for U.S. EPA, Office of Air and Radiation, Air and Energy

Engineering Laboratory, EPA-600/R-95-089, July 1995. 

83.	 TR-076. New Source Performance Standards Tier 2 Sampling and Analysis for the Flying Cloud

Landfill, Browning-Ferris Industries, 6/30/98. 

84. TR-084. Tier 2 NMOC Emission Rate Report for the Buncombe County Landfill, Buncombe 

County Solid Waste Services, 5/12/99. 

85.	 TR-086. Tier 2 NMOC Emission Rate Report for the White Street Landfill, Duke Engineering and 

Services, City of Greensboro Solid Waste Management Division, 5/18/99. 

86.	 TR-114. Summary Report of Tier 2 Sampling, Analysis, and Landfill Emissions Estimates for NonMethane Organic Compounds Chrin Brothers Landfill, Chrin Brothers Sanitary Landfill, 4/24/98. 

87.	 TR-115. Seneca Landfill - Revised Tier 2 NMOC Emission Rate Report, Seneca Landfill, Inc., 

12/5/96. 

88.	 TR-134. New Source Performance Standards Tier 2 Sampling, Analysis, and Landfill NMOC 

Emission Estimates for the Fort Worth Landfill, Laidlaw Waste Systems, Inc., 4/15/97. 

89.	 TR-141. Tier 2 NMOC Emission Rate Report for the SPSA Regional Landfill, Southeastern Public 

Service Authority, MSA Consulting Engineers, 6/10/97. 

90.	 TR-145. Compliance Testing of a Landfill Flare at Browning-Ferris Gas Services, Inc.'s Facility in 

Halifax, Massachusetts, BFI Waste Systems of North America, Inc., May 1996. 

91.	 TR-146. Compliance Source Testing of a Landfill Flare at Northern Disposal, Inc. East 

Bridgewater Landfill, Northern Disposal, Inc., June 1994. 

92.	 TR-147. Compliance Emissions Test Program for BFI of Ohio, Inc., BFI of Ohio, Inc., 6/26/98. 

96
 
 

93.	 TR-148. Compliance Testing of Landfill Flare at Browning-Ferris Gas Services, Inc.'s Fall River 

Landfill Flare, BFI Waste Systems of North America, Inc., March 1995. 

94.	 TR-153. Results of the Emission Compliance Test on the Enclosed Flare System at the Carbon 

Limestone Landfill, Browning-Ferris Industrial Gas Services, Inc., 8/8/96. 

95.	 TR-156. Results of the Emission Compliance Test on the Enclosed Flare System at the Lorain 

County Landfill No. 2, Browning-Ferris Industrial Gas Services, Inc., 9/5/96. 

96.	 TR-157. Emission Compliance Testing Browning-Ferris Gas Services, Inc. Willowcreek Landfill, 

BFI-Willowcreek, 2/2/98. 

97.	 TR-159. Compliance Stack Sampling Report, Monmouth County Reclamation Center, SCS 

Engineers (Reston, VA), 9/8/95. 

98.	 TR-160. Source Emission Testing of an Enclosed Landfill Gas Ground Flare, SCS Engineers 

(Reston, VA), September 1997. 

99.	 TR-163. Compliance Testing for SPADRA Landfill Gas-to-Energy Plant, Ebasco Constructors, 

Inc., November 1990. 

100.	 TR-165. 1997 Annual Compliance Source Testing Results for the Coyote Canyon Landfill Gas 

Recovery Facility Flare No. 1, Laidlaw Gas Recovery Systems, January 1998. 

101.	 TR-167. 1997 Annual Compliance Source Testing Results for the Coyote Canyon Landfill Gas 

Recovery Facility Boiler, Laidlaw Gas Recovery Systems, January 1998. 

102.	 TR-168. Colton Sanitary Landfill Gas Flare No. 2 (John Zink) 1998 Source Tests Results, Bryan A. 

Stirrat & Associates, 9/29/98. 

103.	 TR-169. Colton Sanitary Landfill Gas Flare No. 1 (McGill) 1998 Source Tests Results, Bryan A. 

Stirrat & Associates, 9/29/98. 

104.	 TR-171. High Landfill Gas Flow Rate Source Test Results from One Landfill Gas Flare at FRB 

Landfill in Orange County, California, Bryan A. Stirrat & Associates, July 1997. 

105.	 TR-173. Annual Emissions Test of Landfill Gas Flare #3 Bradley Landfill, Waste Management 

Recycling and Disposal Services of California, Inc., 4/12/99. 

106.	 TR-175. Emissions Tests on Flares #2, #4 and #6 at the Lopez Canyon Landfill, City of Los 

Angeles, August 1997. 

107.	 TR-176. Emissions Test Results on Flares #1, #4 and #9 Calabasas Landfill, County Sanitation 

Districts of Los Angeles County, February 1998. 

108.	 TR-178. Annual Emission Test of Landfill Gas Flare #3 Bradley Landfill, Waste Management 

Recycling and Disposal Services of California, Inc., 5/21/98. 

109.	 TR-179. Annual Emissions Test of Landfill Gas Flare #1 Bradley Landfill, Waste Management 

Recycling and Disposal Services of California, Inc., 4/13/99. 

110.	 TR-181. The Mid-Valley Sanitary Landfill Gas Flare No.1 (McGill) 1998 Source Test Results, 

Bryan A. Stirrat & Associates, 9/29/98. 

111.	 TR-182. The Mid-Valley Sanitary Landfill Gas Flare No.2 (SurLite) 1998 Source Test Results, 

Bryan A. Stirrat & Associates, 9/29/98. 

97
 
112.	 TR-183. Annual Emissions Test of Landfill Gas Flare #2 Bradley Landfill, Waste Management 

Recycling and Disposal Services of California, Inc., 4/13/99. 

113.	 TR-187. Emissions Test of a Landfill Gas Flare - Lowry Landfill/Denver-Arapohoe Disposal Site, 

Sur-Lite Corporation, February 1997. 

114.	 TR-188. Characterization of Emissions from a Power Boiler Fired with Landfill Gas, Environment 

Canada Emissions Research and Measurement Division, March 2000. 

115.	 TR-189. Characterization of Emissions from 925 kWe Reciprocating Engine Fired with Landfill 

Gas, Environment Canada Emissions Research and Measurement Division, December 2000. 

116.	 TR-190. Characterization of Emissions from 812 kWe Reciprocating Engine Fired with Landfill 

Gas, Environment Canada Emissions Research and Measurement Division, December 1999. 

117.	 TR-191. Characterization of Emissions from Enclosed Flare - Trail Road Landfill, Environment 

Canada Emissions Research and Measurement Division, August 2000. 

118.	 TR-194. Characterization of Emissions from 1 MWe Reciprocating Engine Fired with Landfill Gas, 

Environment Canada Emissions Research and Measurement Division, January 2002. 

119.	 TR-195. Characteristics of Semi-volatile Organic Compounds from Vented Landfills, Environment 

Canada Environmental Technology Advancement Directorate, August 1996. 

120.	 TR-196. Results of the Biennial Criteria and AB 2588 Air Toxics Source Test on the Simi Valley

Landfill Flare, Simi Valley Landfill and Recycling Center, April 1997. 

121.	 TR-199. Emission Compliance Test on a Landfill Flare, City of Los Angeles, January 1999. 

122.	 TR-205. The Mid-Valley Sanitary Landfill Gas Flare No. 3 (John Zink) 1998 Source Test Results, 

Bryan A. Stirrat & Associates, 9/29/98. 

123.	 TR-207. Compliance Source Test Report Landfill Gas-fired Flare Stations I-4 and F-2, BKK 

Landfill, 12/12/97. 

124.	 TR-209. Emission Test Report Volumes I and II - Source/Compliance Emissions Testing for Cedar 

Hills Landfill, King County Solid Waste Division, 1/20/05. 

125.	 TR-211. Determination of Total and Dimethyl Mercury in Raw Landfill Gas with Site Screening 

for Elemental Mercury at Eight Washington State Landfills, Washington State Department of 

Ecology, July 2003. 

126.	 TR-212. Determination of Total, and Monomethyl Mercury in Raw Landfill Gas at the Central 

Solid Waste Management Center, Delaware Solid Waste Authority, February 2003. 

127.	 TR-220. SCAQMD Performance Tests on the Spadra Energy Recovery from Landfill Gas 

(SPERG) Facility, County Sanitation Districts of Los Angeles County, April 1992. 

128.	 TR-226. Methane and Nonmethane Organic Destruction Efficiency Tests of an Enclosed Landfill 

Gas Flare, Newco Waste Systems, April 1992. 

129.	 TR-229. Scholl Canyon Landfill Gas Flares No. 9, 10 11 and 12 Emission Source Testing April 

1999, South Coast Air Quality Management District, April 1999. 

130.	 TR-236. Landfill Gas Flare Hydrogen Chloride Emissons Atascocita Landfill, Waste Management 

of Houston, 4/20/99. 

98
 
 

131.	 TR-241. Performance Evaluation, Enclosed Landfill Gas Flare, Valley Landfill, Waste Energy

Technology, November 1991. 

132.	 TR-251. Emission Compliance Test on a Landfill Gas Flare - Flare #1, Frank R. Bowerman 

Landfill, Orange County, 1/25/99. 

133.	 TR-253. Emission Source Testing on Two Flares (Nos. 3 and 6) at the Spadra Landfill, Los 

Angeles County Sanitation Districts, 7/21/98. 

134.	 TR-255. Emission Compliance Test on a Landfill Gas Flare -Olinda Alpha Landfill, Orange County 

Integrated Waste Management Department, No Report Date Given. 

135.	 TR-258. Source Test Report, City of Sacramento Landfill Gas Flare, City of Sacramento, 6/26/96. 

136.	 TR-259. The Millikan Sanitary Landfill Gas Flare No. 1 (Surlite) 1998 Source Test Results, South 

Coast Air Quality Management District, 9/29/98. 

137.	 TR-260. The Millikan Sanitary Landfill Gas Flare No. 2 (John Zink) 1998 Source Test Results, 

South Coast Air Quality Management District, 9/29/98. 

138.	 TR-261. The Millikan Sanitary Landfill Gas Flare No. 3 (John Zink) 1998 Source Test Results, 

South Coast Air Quality Management District, 9/29/98. 

139.	 TR-264. Emission Compliance Test on a Landfill Gas Flare, Orange County Integrated Waste 

Management Department, No Report Date Given. 

140.	 TR-266. Compliance Source Test Report - Landfill Gas-Fired Engine, Minnesota Methane, 3/3/98. 

141.	 TR-268. Emission Testing at PERG - Maximum Boiler Load, County Sanitation Districts of Los 

Angeles County, December 1986. 

142.	 TR-272. Source Testing Final Report - Landfill A, US EPA Air Pollution Prevention and Control 

Division, 10/6/05. 

143.	 TR-273. Source Testing Final Report - Landfill B, US EPA Air Pollution Prevention and Control 

Division, 10/6/05. 

144.	 TR-284. Source Testing Final Report - Landfill C, US EPA Air Pollution Prevention and Control 

Division, 10/6/05. 

145.	 TR-287. Source Testing Final Report - Landfill D, US EPA Air Pollution Prevention and Control 

Division, 10/6/05. 

146.	 TR-290. San Timoteo Sanitary Landfill 1998 Source Test Results, San Bernandino County Solid 

Waste Management, 9/29/98.TR-291. PCDD/PCDF Emissions Tests on the Palos Verdes Energy

Recovery from Landfill Gas (PVERG) Facility, Unit 2, County Sanitation Districts of Los Angeles 

County, February 1994. 

147.	 TR-292. Source Testing Final Report - Landfill E, US EPA Air Pollution Prevention and Control 

Division, October 2005 

148. TR-293. Quantifying Uncontrolled Air Emissions From Two Florida Landfills – Draft Final 

Report. U.S. EPA Air Pollution Prevention and Control Division, March 26, 2008. 

99