EPA-600/R-05/088 

August 2005 

Measurement of Fugitive 

Emissions at a Landfill 

Practicing Leachate 

Recirculation and Air 

Injection 

EPA-600/R-05/088 

August 2005 

Measurement of Fugitive Emissions at

a Landfill Practicing Leachate

Recirculation and Air Injection

by

Mark Modrak, Ram A. Hashmonay, Ravi Varma, and Robert Kagann

ARCADIS G&M, Inc

4915 Prospectus Dr. Suite F,

Durham, NC 27713

Contract Number: EP-C-04-023

Work Assignment Numbers 0-30 and 1-30

Project Officer: Susan Thorneloe

U.S. Environmental Protection Agency

National Risk Management Research Laboratory

Air Pollution Prevention and Control Division

Research Triangle Park, NC 27711

U.S. Environmental Protection Agency

Office of Research and Development

Washington, DC 20460
Abstract 

Recently, research has begun on operating bioreactor landfills. The bioreactor process involves 

the injection of liquid into the waste mass to accelerate waste degradation. The EPA and 

ARCADIS conducted a fugitive emission characterization study at the Three Rivers Solid 

Waste Technology Center Landfill located near Jackson, South Carolina. The survey area is a 

two acre research and development site that practices leachate recirculation and air injection. 

The site is located within the Subtitle D Landfill. 

The focus of this study is to evaluate emissions of fugitive gases, such as methane and 

hazardous air pollutants, at the site using scanning open-path Fourier transform infrared 

spectrometers and open-path tunable diode laser absorption spectroscopy. The study involved 

a technique developed through research funded by the EPA National Risk Management 

Research Laboratory, which uses ground-based optical remote sensing technology, known as 

radial plume mapping. The horizontal radial plume mapping (HRPM) method was used to map 

surface methane concentrations, and the vertical radial plume mapping (VRPM) method was 

used to measure emissions fluxes downwind of the site. 

HRPM surveys detected the presence of a methane hot spot near the center of the site, with peak 

concentrations ranging from over 26 ppm to over 48 ppm above ambient background levels. 

An additional HRPM survey was conducted, at the request of the site operator, while leachate 

was being pumped from a small holding pond located in the southeast corner of the site to 

another small holding pond located in the northwest corner of the site. This survey detected an 

additional methane hot spot located near the northwest corner of the site with concentrations 

greater than 23 ppm above ambient background levels. 

The results of the VRPM surveys found upwind methane flux values between 14 and 20 g/s, 

and downwind methane flux values between 10 and 18 g/s. The downwind methane flux values 

from 21 and 22 January 2004, are probably lower than the corresponding upwind values 

because the prevailing winds at the time of the surveys carried a large portion of the plume from 

the upwind hot spot outside of the downwind VRPM configurations. 

ii 
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 Gutierrez, Director 

National Risk Management Research Laboratory 

iii 
EPA Review Notice 

This report has been peer and administratively reviewed by the U.S. Environmental Protection 

Agency and approved for publication. Mention of trade names or commercial products does not 

constitute endorsement or recommendation for use. 

This document is available to the public through the National Technical Information Service, 

Springfield, Virginia 22161. 

iv 
Contents 

Section Page 

Abstract ................................................................. ii

List of Tables ........................................................... vii

List of Figures ........................................................... ix

Executive Summary .................................................... ES-1

1. Project Description and Objectives ...................................... 1-1

1.1 Background ................................................... 1-1

1.2 Project Description and Purpose ................................... 1-2

1.2.1 Horizontal RPM .......................................... 1-3

1.2.2 Vertical RPM ............................................ 1-3

1.3 Quality Objectives and Criteria .................................... 1-4

1.4 Project Schedule ................................................ 1-7

2. Testing Procedures ................................................... 2-1

2.1 HRPM Surveys ................................................. 2-2

2.2 VRPM Measurements ........................................... 2-3

2.2.1 VRPM Survey of 20 January 2004 ........................... 2-3

2.2.2 VRPM Surveys of 21 January 2004 . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3

2.2.3 VRPM Survey of 22 January 2004 ........................... 2-4

2.3 Single Path Measurement During Leachate Pump Operation ............. 2-4

2.4 OP-TDLAS Measurements ....................................... 2-4

3. Results and Discussion ................................................ 3-1

3.1 The Horizontal RPM Results ...................................... 3-1

3.2 The Vertical RPM Results ........................................ 3-2

3.2.1 VRPM Survey of 20 January 2004 ........................... 3-3

3.2.2 VRPM Surveys of 21 January 2004 . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4

3.2.3 VRPM Survey of 22 January 2004 ........................... 3-6

3.3 Results from the Single-Path Measurement During Leachate

Pump Operation ................................................ 3-8

3.4 VOC and Ammonia Results ....................................... 3-8

4. Conclusion ......................................................... 4-1

5. QA/QC ............................................................ 5-1

5.1 Equipment Calibration ........................................... 5-1

5.2 Assessment of DQI Goals ........................................ 5-1

5.2.1 DQI Check for Analyte PIC Measurement ..................... 5-2

v 
Contents (concluded) 

Section Page 

5.2.2 DQI Checks for Ambient Wind Speed and Wind

Direction Measurements ............................... 5-2

5.2.3 DQI Check for Precision and Accuracy of Theodolite Measurements 5-3

5.3 QC Checks of OP-FTIR Instrument Performance ...................... 5-3

5.4 Validation of Concentration Data Collected with the OP-FTIR ........... 5-3

5.5 Internal Audit of Data Input Files .................................. 5-4

5.6 OP-TDLAS Instrument .......................................... 5-4

5.7 Difficulties Encountered ......................................... 5-4

6. References ......................................................... 6-1

Appendix A: OP-FTIR Mirror Coordinates ................................... A-1

Appendix B: OP-TDLAS Configuration Path Length Distances .................. B-1

Appendix C: Methane Concentrations ....................................... C-1

vi 
List of Tables 

Table Page 

ES-1. Average Calculated Methane Fluxes Found During the Upwind and 

Downwind VRPM Surveys ......................................... ES-2

1-1. DQI Goals for Critical Measurements .................................. 1-4

1-2. Detection Limits for Target Compounds ................................ 1-5

1-3. Schedule of Work Performed at the Site ................................ 1-7

3-1. Moving Average of Calculated Methane Flux, CCF, Wind Speed, and

Wind Direction for 01/20/04 Upwind VRPM Survey ...................... 3-3

3-2. Moving Average of Calculated Methane Flux, CCF, Wind Speed, and

Wind Direction for 01/21/04 Afternoon Upwind VRPM Survey 

(Collected with OP-TDLAS) ......................................... 3-4

3-3. Moving Average of Calculated Methane Flux, CCF, Wind Speed, and

Wind Direction for 01/21/04 Afternoon Downwind VRPM Survey 

(Collected with OP-FTIR) ........................................... 3-4

3-4. Moving Average of Calculated Methane Flux, CCF, Wind Speed, and

Wind Direction for 01/22/04 Upwind VRPM Survey 

(Collected with OP-TDLAS) ......................................... 3-6

3-5. Moving Average of Calculated Methane Flux, CCF, Wind Speed, and

Wind Direction for 01/22/04 Downwind VRPM Survey 

(Collected with OP-FTIR) ........................................... 3-6

3-6. Average Ammonia and Methanol Concentrations Measured ................ 3-8

4-1. Average Calculated Methane Fluxes Found During the Upwind and Downwind 

VRPM Surveys .................................................... 4-1

5-1. Instrumentation Calibration Frequency and Description .................... 5-1

5-2. DQI Goals for Instrumentation ....................................... 5-2

A-1. Distance, and Horizontal and Vertical Coordinates of Mirrors Used

in the 01/20/04 Upwind VRPM Survey ................................. A-1

A-2. Distance, and Horizontal and Vertical Coordinates of Mirrors Used

in the 01/20/04 Downwind VRPM Survey .............................. A-1

A-3. Distance and Horizontal and Vertical Coordinates of Mirrors Used

in the 01/21/04 Upwind VRPM Survey ................................. A-1

A-4. Distance and Horizontal and Vertical Coordinates of Mirrors Used

in the 01/21/04 Downwind VRPM Survey .............................. A-1

A-5. Distance, and Horizontal Coordinates of Mirrors Used in the 01/21/04

HRPM Survey of Site ............................................... A-2

vii 
List of Tables (concluded) 

Table Page 

A-6. Distance, and Horizontal Coordinates of Mirrors Used in the 01/22/04 

HRPM Survey of Site .............................................. A-2

A-7. Distance, and Horizontal and Vertical Coordinates of Mirrors Used

in the 01/22/04 VRPM Survey of Site .................................. A-2

B-1. Distance and Horizontal and Vertical Coordinates of Mirrors Used

in OP-TDLAS Configuration ........................................ B-1

C-1. Methane Concentrations (in PPM) found during the 01/20/04 Upwind

VRPM Survey .................................................... C-1

C-2. Methane Concentrations (in PPM) found during the 01/21/04 Upwind

VRPM Surveys ................................................... C-1

C-3. Methane Concentrations (in PPM) found during the 01/21/04 Downwind

VRPM Surveys ................................................... C-2

C-4. Methane Concentrations (in PPM) found during the 01/21/04 HRPM Survey . . C-2

C-5. Methane Concentrations (in PPM) found during the 01/22/04 Downwind

VRPM Surveys ................................................... C-3

C-6. Methane Concentrations (in PPM) found during the 01/22/04 HRPM Survey . . C-3

viii 
List of Figures 

Figure Page 

1-1. Survey Area at the Three Rivers Landfill ............................... 1-1

1-2. OP-TDLAS System ................................................ 1-3

1-3. Example of a HRPM Configuration .................................... 1-3

1-4. Example of a VRPM Configuration .................................... 1-4

2-1. Schematic of the HRPM Configuration Used During the 01/21/04 Survey ..... 2-2

2-2. Schematic of the HRPM Configuration Used During the 01/22/04 Surveys ..... 2-2

2-3. Map of Three Rivers Landfill Showing the Location of the Survey Site

and the VRPM Configurations Used During 01/20/04 Survey ............... 2-3

2-4. Map of Three Rivers Landfill Showing the Location of the Survey Site

and the VRPM Configurations Used During 01/21 and 01/22/04 Surveys ...... 2-3

2-5. Upwind Configuration from the Morning VRPM Survey on 01/21/04 ......... 2-4

2-6. OP-TDLAS Configuration Used at the Site .............................. 2-4

3-1. Average Surface Methane Concentration Contour Map from the HRPM

Survey of 01/21/04 ................................................. 3-1

3-2. Average Surface Methane Concentration Contour Map from 01/22/04

Morning HRPM Survey ............................................. 3-2

3-3. Average Surface Methane Concentration Contour Map from 01/22/04

Afternoon HRPM Survey ............................................ 3-2

3-4. Average Reconstructed Methane Plume from the 01/20/04 Upwind

VRPM Survey .................................................... 3-3

3-5. Average Reconstructed Methane Plume from the 01/21/04 Afternoon

Upwind VRPM Survey ............................................. 3-5

3-6. Average Reconstructed Methane Plume from the 01/21/04 Afternoon

Downwind VRPM Survey ........................................... 3-5

3-7. Average Reconstructed Methane Plume from the 01/22/04 Upwind

VRPM Survey .................................................... 3-7

3-8. Average Reconstructed Methane Plume from the 01/22/04 Downwind

VRPM Survey .................................................... 3-8

5-1. Comparison of a Spectrum Measured at the Site (Blue Trace) to the Reference

Spectra of Methanol (Red Trace) and Ammonia (Purple Trace) .............. 5-4

5-2. Comparison of Methane Concentrations Measured with the OP-TDLAS

and OP-FTIR Instruments ........................................... 5-5

ix 
Measurement of Fugitive Emissions at a Landfill 

x 
Practicing Leachate Recirculation and Air Injection 

Executive Summary

Background and Site Information

There has been much concern over the potential 

hazards of landfill gas emissions. The predominant 

component of landfill gas emissions is methane, 

which is highly flammable and has been identified as 

a major greenhouse gas implicated in global warming. Another issue with landfill gas emissions is odor 

nuisance complaints due to trace constituents. 

Recently research has begun on operating bioreactor 

landfills. The bioreactor process involves the injection of liquid such as leachate or sludge into the 

waste mass. In the case of aerobic bioreactor landfills, air is injected into the waste mass in addition to 

the liquid material to induce aerobic microorganisms 

to degrade the waste more rapidly. The goals of this 

technique are to increase landfill space (resulting in 

more cost-effective landfill practices), to bring the 

waste as close to full maturation as is feasible with 

the technology, and to eliminate both potential 

environmental threats from concentrated leachate and 

hazards associated with methane gas production. 

The EPA and ARCADIS conducted a fugitive emission characterization study at the Three Rivers Solid 

Waste Technology Center Landfill located near 

Jackson, South Carolina. The survey area is a twoacre research and development site that practices 

leachate recirculation and air injection. The site is 

located in Cell 1 of the Three River Regional Subtitle 

D Landfill. The focus of this study was to evaluate 

emissions of fugitive gases, such as methane and 

hazardous air pollutants (HAPs) at the site. 

Testing Procedures

Data was collected at the site using two open-path 

Fourier transform infrared (OP- FTIR) spectrometers 

and an open-path tunable diode laser absorption 

spectroscopy (OP- TDLAS) system. Three horizontal 

radial plume mapping (HRPM) surveys were done 

along the surface of the site to search for surface 

emissions hot spots. The last HRPM survey was 

conducted while leachate was being pumped (through 

a hose that extended diagonally across the surface of 

the survey area) from a small holding pond located in 

the southeast corner of the site to another small 

holding pond located in the northwest corner of the 

site. Vertical radial plume mapping (VRPM) surveys 

were performed over three days using two vertical 

configurations to measure emissions of fugitive gases 

and volatile organic compounds (VOCs) upwind and 

downwind of the top surface site. 

Results and Discussion 

HRPM Results 

HRPM surveys conducted on 21 and 22 January 2004 

detected the presence of a methane hot spot near the 

center of the site that had peak concentrations ranging 

from over 26 ppm to over 48 ppm above ambient 

background levels. An HRPM survey was conducted 

on the afternoon of 22 January with leachate being 

pumped from a small holding pond at the southeast 

corner of the site to another small holding pond 

located at the northwest corner of the site. This 

survey detected an additional methane hot spot 

located near the northwest corner of the site that had 

concentrations greater than 23 ppm above ambient 

ES-1
Table ES-1. Average Calculated Methane Fluxes 

Found During the Upwind and Downwind VRPM 

Surveys. 

Calculated Up- Calculated DownSurvey wind (Western) wind (Eastern) 

Date Methane Flux Methane Flux 

(g/s) (g/s) 

1/20/2004 

1/21/2004 

1/22/2004 

15 

14b 

20b 

N/Aa 

10c 

18c 

a 

b 

c 

Downwind methane flux data from the 01/20/2004 VRM Survey 

is not available due to software problems in the field. 

Upwind methane flux data from 01/21 and 01/22/04 were collected with the OP-TDLAS instrument due to software problems 

with the Midac OP-FTIR. 

Calculated downwind methane flux values are lower than the 

corresponding upwind values because the entire methane plume 

was not captured by the downwind VRPM configuration. 

Measurement of Fugitive Emissions at a Landfill 

background levels. This hot spot is probably associated with emissions from the leachate being pumped 

to the holding pond located at the northwest corner of 

the cell. 

VRPM Results 

VRPM surveys were done at the site on each day of 

the field campaign. Table E-1 presents the calculated 

methane fluxes from each survey. 

The results of the VRPM surveys found that, in many 

cases, the upwind calculated methane fluxes were 

higher than the downwind methane fluxes. This was 

probably due to the fact that a methane hot spot may 

have been present on the side slope located on the 

western side of the survey area (directly upwind of 

the upwind VRPM configuration). Several relief 

wells were observed along the surface of this side 

slope, and elevated methane concentrations were 

measured along an OP-TDLAS beam path deployed 

in the vicinity of these wells. The existence of a 

methane hot spot along the side slope is also supported by the shape of the upwind methane plume 

maps generated by the VRPM software (see Section 

3.2.1). The downwind methane flux values from 21 

and 22 January are probably lower than the corresponding upwind values because the prevailing winds 

at the time of the surveys carried a large portion of 

the plume from the upwind hot spot outside of the 

downwind VRPM configuration, which was substantially shorter than the upwind VRPM configuration. 

VOC and Ammonia Results 

The datasets from the HRPM and VRPM surveys 

were searched for the presence of VOCs and ammonia. The analysis detected ammonia and methanol at 

the site. The measured ammonia concentrations 

ranged from 2.8 to 37 ppb. Methanol was detected 

only during the 21 January single-path measurements 

conducted with the leachate pump operating. The 

measured methanol concentration was 11 ppb. 

ES-2
Practicing Leachate Recirculation and Air Injection 

Chapter 1

Project Description and Objectives

1.1 Background

There has been much concern over the potential 

hazards of landfill gas emissions. The predominant 

component of landfill gas emissions is methane, 

which is highly flammable and has been identified as 

a major greenhouse gas implicated in global warming. Another issue with landfill emissions is odor 

nuisance complaints due to trace constituents. 

Recently, research has begun on operating bioreactor 

landfills. The bioreactor process involves the injection of liquid such as leachate or sludge into the 

waste mass. In the case of aerobic bioreactor landfills, air is injected into the waste mass in addition to 

the liquid to induce aerobic microorganisms to degrade the waste more rapidly. The goals of this 

technique are to increase landfill space (resulting in 

more cost-effective landfill practices), to bring the 

waste as close to full maturation as is feasible with 

the technology, and to eliminate potential environmental threats due to concentrated leachate and 

hazards associated with methane gas production. 

EPA and ARCADIS conducted a fugitive emission 

characterization study at the Three Rivers Solid 

Waste Technology Center Landfill located near 

Jackson, SC. The survey site is a two- acre research 

and development area located in Cell 1 of the Three 

River Regional Subtitle D Landfill (see Figure 1-1). 

The landfill system includes a network of piping that 

collects and injects leachate from the Three Rivers 

Regional Landfill into the waste while, at the same 

Figure 1-1. Survey Area at the Three Rivers 

Landfill. 

time, injecting air into the waste in order to stimulate 

aerobic conditions within the landfill to initiate and 

maintain the rapid decay of waste. The survey area is 

approximately 60 feet deep and consists of about 

70,000 cubic yards of waste and daily cover. 

The focus of this study is to evaluate emissions of 

fugitive gases such as methane and hazardous air 

pollutants (HAPs) at the site using an open-path 

Fourier transform infrared (OP-FTIR) spectrometer 

and an open-path tunable diode laser absorption 

spectroscopy (OP-TDLAS). The study involved a 

technique developed through research funded by the 

U.S. Environmental Protection Agency (EPA) National Risk Management Research Laboratory 

(NRMRL), which uses ground-based optical remote 

sensing instrumentation, known as radial plume 

mapping (RPM) (Hashmonay and Yost, 1999; 

1-1
Measurement of Fugitive Emissions at a Landfill 

Hashmonay et al., 1999; Wu et al., 1999; Hashmonay 

et al., 2001; Hashmonay et al., 2002). The survey 

identified emission hot spots (areas of relatively 

higher emissions), investigated source homogeneity, 

and calculated an emission flux rate for methane 

detected at the site. Concentration maps in the horizontal and downwind vertical planes were generated 

using the horizontal radial plume mapping (HRPM), 

and vertical radial plume mapping (VRPM) methods, 

respectively. 

The study consisted of one field campaign performed 

during January 2004 by EPA and ARCADIS personnel. 

1.2 Project Description and Purpose

The optical remote scanning (ORS) techniques used 

in this study were designed to characterize the emissions of fugitive gases from area sources. Spatial 

information is obtained from multi-path ORS measurements by the use of iterative search algorithms. 

The HRPM method involves the use of a configuration of nonoverlapping radial beam geometry to map 

the concentration distributions in a horizontal plane. 

The VRPM method is applied to a vertical plane 

downwind from an area emission source to map the 

crosswind and vertical profiles of a plume. By incorporating wind information, the flux through the plane 

is calculated, which leads to an emission rate of the 

upwind area source. An OP-FTIR sensor was chosen 

as the primary instrument for the study because of its 

capability of accurately measuring a large number of 

chemical species that might occur in a plume. 

The OP-FTIR spectrometer combined with the RPM 

method is designed for both fence-line monitoring 

applications, and real-time, on-site, remediation 

monitoring and source characterization. An infrared 

light beam modulated by a Michelson interferometer 

is transmitted from a single telescope to a retroreflector (mirror) target, which is usually set up at a 

range of 100 to 500 meters. The returned light signal 

is received by the single telescope and directed to a 

detector. Some of the light is absorbed by the molecules in the beam path as the light propagates to the 

mirror, and more is absorbed as the light is reflected 

back to the analyzer. Thus, the round-trip path of the 

light doubles the chemical absorption signal. One 

advantage of OP-FTIR monitoring is that the concentrations of a multitude of infrared absorbing gaseous 

chemicals can be detected and measured simultaneously with high temporal resolution. 

The OP-TDLAS system (Unisearch Associates) is a 

fast, interference-free technique for making continuous concentration measurements of many gases. The 

OP-TDLAS used in the current study is capable of 

measuring concentrations over an open path up to 1 

km in the range of tens of parts per billion for gases 

such as carbon monoxide (CO), carbon dioxide 

(CO2), ammonia (NH3), and methane (CH4). The laser 

emits radiation at a particular wavelength when an 

electrical current is passed through it. The light 

wavelength depends on the current and, therefore, 

allows scanning over an absorption feature and 

analyzing for the target gas concentration using 

Beer’s law. The OP-TDLAS used in this study is a 

multiple channel TDL instrument that allows fast 

scanning electronically (few seconds) among many 

beam-paths (presently, 8 beams). The OP-TDLAS 

applies a small 4-inch telescope, which launches the 

laser beam to a mirror. The laser beam is returned by 

the mirror to the telescope, which is connected with 

fiber optics to a control box that houses the laser and 

a multiple channel detection device. For this particular field campaign, data from the OP-TDLAS were 

used to provide information on methane concentrations at the site. Figure 1-2 shows a picture of the 

OP-TDLAS system used in the current study. 

Meteorological and survey measurements were also 

made during the field campaign. A theodolite was 

used to make the survey measurement of the azimuth 

and elevation angles and the radial distances to the 

mirrors, relative to the OP-FTIR sensor. 

The objectives of the study are: 

• Collect OP-FTIR data in order to identify major 

emissions hot spots by generating surface concentration maps in the horizontal plane, and 

1-2
Practicing Leachate Recirculation and Air Injection 

Figure 1-2. OP-TDLAS System. 

over several scanning cycles to produce concentration 

maps that are time-averaged (Hashmonay et al., 

1999). Meteorological measurements are made 

concurrent to the scanning measurements. 

Figure 1-3 represents a typical HRPM configuration. 

In this particular case, n = m = 3. The solid lines 

represent the nine optical paths, each terminating at 

a mirror. 

• Measure emission fluxes of detectable compounds downwind from major hot spots.

1.2.1 Horizontal RPM 

The HRPM approach provides spatial information to 

path-integrated measurements acquired in a horizontal plane by an ORS system. This technique yields 

information on the two-dimensional distribution of 

the concentrations in the form of chemical concentration contour maps. This form of output readily 

identifies chemical “hot spots,” the location of high 

emissions. This method can be of great benefit for 

performing site surveys before, during, and after site 

remediation activities. 

One OP-FTIR instrument (manufactured by IMACC, 

HRPM scanning is usually performed with the ORS Inc.) was used to collect horizontal RPM data during 

beams located as close to the ground as is practical. the field campaign. 

This enhances the ability to detect minor constituents 

emitted from the ground since the emitted plumes 1.2.2 Vertical RPM 

dilute significantly at higher elevations. The survey The VRPM method maps the concentrations in the

area is typically divided into a Cartesian grid of n vertical plane by scanning the ORS system in a

times m rectangular cells. In some unique cases, the vertical plane downwind from an area source. The

survey area may not be rectangular due to obstruc- plane-integrated concentration can be obtained from

tions, and the shape of the cells may be slightly the reconstructed concentration maps. The flux is

altered accordingly. A mirror is located in each of calculated by multiplying the plane-integrated conthese cells, and the ORS sensor scans to each of these centration by the wind speed component perpendicumirrors, dwelling on each for a set measurement time lar to the vertical plane. Thus, the VRPM method 

(30 seconds in the present study). The system scans leads to a direct measurement-based determination of 

to the mirrors in the order of either increasing or the upwind source emission rate (Hashmonay et al., 

decreasing azimuth angle. The path-integrated con- 1998; Hashmonay and Yost, 1999, Hashmonay et al., 

centrations measured at each mirror are averaged 2001). 

Figure 1-3. Example of a HRPM Configuration. 

1-3
Table 1-1. DQI Goals for Critical Measurements. 

Analysis Parameter Method Accuracy 

(% bias) 

Precision 

(%RSD) Completeness 

Analyte PICa OP-FTIR: nitrous oxide concentrations 

±25%/15%/10%b ±10% 90% 

Ambient Wind Speed Climatronics Met heads side-byside comparison in the field ±1 m/s ±1 m/s 90% 

Ambient Wind Direction Climatronics Met heads side-byside comparison in the field ±10° ±10° 90% 

Distance Theodolite- Topcon ±1 m ±1 m 100% a 

b 

PIC = path-integrated concentration. 

The accuracy acceptance criterion of ±25% is for pathlengths of less than 50m, ±15% is for pathlengths between 50 and 100m, and ±10% is 

for pathlengths greater than 100m. 

Measurement of Fugitive Emissions at a Landfill 

Figure 1-4 shows a schematic of the experimental 

setup used for vertical scanning. Several mirrors are 

placed in various locations on a vertical plane in-line 

with the scanning OP FTIR. A vertical platform 

(scissors jack) is used to place two of the mirrors at a 

predetermined height above the surface. The location 

of the vertical plane is selected so that it intersects the 

mean wind direction as close to perpendicular as 

practical. Two OP-FTIR instruments (manufactured 

by Midac, Inc. and IMACC, Inc.) were used to 

complete the VRPM surveys. 

1.3 Quality Objectives and Criteria

Data quality objectives (DQOs) are qualitative and 

quantitative statements developed using EPA’s DQO 

process (U.S. EPA, 2000) that clarify study objectives, define the appropriate type of data, and specify 

tolerable levels of potential decision errors that will 

be used as the basis for establishing the quality and 

quantity of data needed to support decisions. DQOs 

define the performance criteria that limit the probabilities of making decision errors by considering the 

purpose of collecting the data, defining the appropriate type of data needed, and specifying tolerable 

probabilities of making decision errors. 

Quantitative objectives are established for critical 

measurements using the data quality indicators 

(DQIs) of accuracy, precision, and completeness. The 

Figure 1-4. Example of a VRPM Configuration. 

acceptance criteria for these DQIs are summarized in 

Table 1-1. Accuracy of measurement parameters is 

determined by comparing a measured value to a 

known standard, assessed in terms of percent bias. 

Values must be within the listed tolerance to be 

considered acceptable. 

1-4
Table 1-2. Detection Limits for Target Compounds. 

OP-FTIR Estimated Detection AP-42 Value as a ratio to an

Limit for Path Length = 100m, Compound 1 min Average average methane concentration of 50 ppma

(ppmv) (ppmv)

1,4-Dichlorobenzene 0.012 0.000021 

2-Propanol 0.0060 0.0050 

Acetone 0.024 0.00070 

Acrylonitrile 0.010 0.00063 

Ammonia 0.0040 N/Ab 

Butane 0.0060 0.00050 

Chlorobenzene 0.040 0.000025 

Chloroform 0.012 0.0000030 

Chloromethane 0.012 0.00010 

Dichlorodifluoromethane 0.0040 0.0016 

Dimethyl sulfide 0.018 0.00078 

Ethane 0.010 0.089 

Ethanol 0.0060 0.0027 

Ethyl benzene 0.060 0.00046 

Ethyl chloride 0.0040 0.00013 

Ethylene dibromide 0.0060 0.00000010 

Practicing Leachate Recirculation and Air Injection 

Precision is evaluated by making replicate measurements of the same parameter and by assessing the 

variations of the results. Precision is assessed in 

terms of relative percent difference (RPD), or relative 

standard deviation (RSD). Replicate measurements 

are expected to fall within the tolerances shown in 

Table 1-1. Completeness is expressed as a percentage 

of the number of valid measurements compared to the 

total number of measurements taken. 

Estimated minimum detection limits (MDLs) of the 

OP-FTIR instrument are given by compound in Table 

1-2. It is important to note that the values listed in 

Table 1-2 should be considered first step approximations because the MDL is highly variable and depends on many factors including atmospheric conditions. Actual MDLs are calculated in the quantification software for all measurements taken. Minimum 

detection levels for each absorbance spectrum are 

determined by calculating the root mean square 

(RMS) absorbance noise in the spectral region of the 

target absorption feature. The MDL is the target 

compound absorbance signal that is five times the 

RMS noise level, using a reference spectrum acquired 

for a known concentration of the target compound. 

Guidance documents such as Compendium Method 

TO-16 (U.S. EPA, 1999) and American Society for 

Testing and Materials (ASTM) Standard Practices 

E1982-98 (ASTM, 1999) typically define estimated 

minimum detection limits (MDL) as 3 times the RMS 

noise. However, signals at this level may be due to 

the presence of a given compound or may be false 

positives. The estimate of five times the RMS noise 

reduces the probability of measuring false positives 

and was therefore used in the analysis of the current 

data set to provide more conservative results. 

continued 

1-5
Measurement of Fugitive Emissions at a Landfill 

Table 1-2. Detection Limits for Target Compounds (concluded). 

OP-FTIR Estimated Detection AP-42 Value as a ratio to an 

Compound Limit for Path Length = 100m, average methane concentra1 min Average tion of 50 ppma 

(ppmv) (ppmv) 

Ethylene dichloride 0.030 0.000041 

Fluorotrichloromethane 0.0040 0.000076 

Hexane 0.0060 0.00066 

Hydrogen sulfide 6.0 0.0036 

Methane 0.024 N/A 

Methanol 0.0015 N/A 

Methyl ethyl ketone 0.030 0.00071 

Methyl isobutyl ketone 0.040 0.00019 

Methyl mercaptan 0.060 0.00025 

Methylene chloride 0.014 0.0014 

Octane 0.0025 N/A 

Pentane 0.0080 0.00033 

Propane 0.0080 0.0011 

Propylene dichloride 0.014 0.000018 

Tetrachloroethene 0.0040 0.00037 

Trichlorethylene 0.0040 0.00028 

Vinyl chloride 0.010 0.00073 

Vinylidene chloride 0.014 0.000020 

Xylenes 0.030 0.0012 

a The AP-42 values represent an average concentration of different pollutants in the raw landfill gas. This is not comparable 

to the detection limits for the OP-FTIR which is an average value for a path length of 100 meters across the surface of the 

area source being evaluated. However, it does provide an indication of the types of pollutants and range of concentrations 

associated with landfill gas emissions in comparison to the detection limits of the OP-FTIR. b N/A = not available. 

1-6
Day 

(2004) Detail of Work Performed Notes 

Tuesday, 20 January PM-VRPM survey of site Due to software problems, downwind VRPM data was 

2004 not available from this survey 

Wednesday, 21 January AM-VRPM survey of site Data from AM VRPM survey was not reported because 

2004 PM-HRPM survey of site 

PM-VRPM survey of site 

the wind data failed to meet the acceptance criteria 

Thursday, 22 January AM-HRPM survey of site 

2004 PM-VRPM survey of site 

PM-HRPM survey of site 

while leachate pump was operating 

Practicing Leachate Recirculation and Air Injection 

1.4 Project Schedule

The field campaign for this study was completed during January 2004. Table 1-3 provides the schedule of ORS 

work that was performed. 

Table 1-3. Schedule of Work Performed at the Site. 

1-7
Measurement of Fugitive Emissions at a Landfill 

1-8 
Practicing Leachate Recirculation and Air Injection 

Chapter 2

Testing Procedures

The following subsections describe the testing procedures used at the site. HRPM was performed along 

the surface of the survey area to produce surface 

concentration maps and to locate any emissions hot 

spots. VRPM was performed using two OP-FTIR 

instruments, and the OP-TDLAS system. The coordinates of the mirrors used in each configuration (relative to the position of the ORS instrument) are presented in Appendix A and B. 

OP-FTIR raw data were collected as interferograms. 

All data were archived to CD-ROMs. After archiving, 

interferograms were transferred to ARCADIS. They 

were then transformed to single beam spectra, and 

concentrations were calculated using Non-Lin 

(Spectrosoft) quantification software. This analysis 

was done after completion of the field campaign. 

Concentration data were then matched with the 

appropriate mirror locations, wind speed, and wind 

direction. The ARCADIS RPM software was used to 

process the data into horizontal plane or vertical plane 

plume visualizations, as appropriate. 

Meteorological data including wind direction, wind 

speed, temperature, relative humidity, and barometric 

pressure were continuously collected during the 

measurement campaign with an automated R.M. 

Young instrument. It collected real-time data from its 

sensors and recorded time-stamped data as onesecond averages to the data collection computer. 

Sensing heads for wind direction and speed were used 

to collect data at the surface during the HRPM surveys and at 2 and 10 meters heights during the VRPM 

survey (the 10-m sensor was placed on top of the 

scissors jack that held the mirrors). The sensing 

heads for wind direction incorporate an auto-north 

function (automatically adjusts to magnetic north) 

that eliminates the errors associated with subjective 

field alignment to a compass heading. After data 

collection, a linear interpolation between the two sets 

of data was done to estimate wind velocity as a 

function of height. 

Once the concentrations maps and wind information 

were processed, the concentration values were 

integrated, incorporating the wind speed component 

normal to the plane at each height level to compute 

the flux through the vertical plane. In this stage, the 

concentration values were integrated from parts per 

million by volume to grams per cubic meter, considering the molecular weight of the target gas. This 

enables the direct calculation of the flux in grams per 

second, using wind speed data in meters per second. 

The concordance correlation factor (CCF) is used to 

represent the level of fit for the reconstruction in the 

path-integrated domain—predicted vs. observed 

path-integrated concentration (PIC). The CCF is 

similar to the Pearson correlation coefficient (r), but 

is adjusted to account for shifts in location and scale. 

Like the Pearson correlation, CCF values are 

bounded between -1 and +1, yet the CCF can never 

exceed the absolute value of the Pearson correlation 

factor. For example, the CCF will be equal to the 

Pearson correlation when the linear regression line 

intercepts the ordinate at 0, and its slope equals 1. Its 

2-1
Measurement of Fugitive Emissions at a Landfill 

absolute value will be lower than the Pearson correlation when the above conditions are not met. For the 

purposes of this report, the closer the CCF value is to 

+1, the better the fit for the reconstruction in the pathintegrated domain. 

In reporting the average calculated flux, a moving 

average is used in the calculation of the average flux 

values to show temporal variability in the measurements. A moving average involves averaging flux 

values calculated from several different consecutive 

cycles (a cycle is defined as data collected when 

scanning one time through all the mirrors in the 

configuration). For example, a data set taken from 5 

cycles may be reported using a moving average of 4, 

where values from cycles 1 to 4, and 2 to 5 are averaged together to show any variability in the flux 

values. 

2.1 HRPM Surveys

One HRPM survey was conducted along the surface 

of the survey area on 21 January 2004 and two 

HRPM surveys were conducted on 22 January 2004. 

During the second HRPM survey on 22 January, 

leachate was being pumped (through a hose that 

extended diagonally across the surface of the survey 

area from a small holding pond at the southeast 

corner of the site to another small holding pond at the 

northwest corner of the site. During the HRPM 

surveys, the optical paths were configured as close to 

the surface of the cell as possible (less than one 

meter above the surface). Figures 2-1 and 2-2 present 

the HRPM configurations used during the 21 and 22 

January HRPM surveys, respectively. The solid lines 

represent the nine optical paths used in the configuration, each terminating at a mirror. The same terrain 

Figure 2-1. Schematic of the HRPM Config- Figure 2-2. Schematic of the HRPM Configuration Used During the 01/21/04 Survey. uration Used During the 01/22/04 Surveys. 

2-2
Practicing Leachate Recirculation and Air Injection 

was surveyed on both days, but the OP-FTIR was 

placed in a different corner of the area on each day. 

2.2 VRPM Measurements 

VRPM surveys were conducted at the site during each 

day of the field campaign using two ORS instruments. 

The VRPM surveys were completed using two 

vertical configurations set up along the eastern and 

western boundary of the survey area. Due to geographical limitations at the site, the VRPM configuration along the eastern boundary of the site was limited 

to a distance of 95 meters. Figure 2-3 presents the 

overall layout of the site and the location of the 

VRPM configurations used during 20 January. Figure 

2-4 shows the location of the VRPM configurations 

used during 21 and 22 January. In both figures, the 

blue cylinders indicate the locations of the ORS 

instruments, and the blue squares indicate the locations of the scissors jacks (vertical structures) used in 

the configurations. 

Figure 2-3. Map of Three Rivers Landfill Showing 

the Location of the Survey Site and the VRPM 

Configurations Used During 01/20/04 Survey. 

During each survey, one vertical configuration served 

as the upwind measurement of the top surface of the 

site, and the other served as the downwind measurement of the top surface, depending on the prevailing 

wind direction. The use of an upwind VRPM configuFigure 2-4. Map of Three Rivers Landfill Showing 

the Location of the Survey Site and the VRPM 

Configurations Used During 01/21 and 01/22/04 

Surveys. 

ration allowed for the identification of any upwind 

source and the calculation of a flux value for the 

identified sources. 

2.2.1 VRPM Survey of 20 January 2004 

The observed wind direction was westerly during the 

VRPM survey of 20 January. The IMACC instrument was located along the western boundary (upwind) of the survey area, and the Midac instrument 

was located along the eastern boundary (downwind) 

of the area. The upwind configuration consisted of 

three mirrors placed along the surface and two 

mirrors placed on the upwind scissors jack. Due to 

software problems with the scanner controlling the 

Midac instrument, data was not collected with this 

instrument. 

2.2.2 VRPM Surveys of 21 January 2004 

Two VRPM surveys were conducted at the site on 21 

January. During the morning VRPM survey, the 

observed wind direction was southeasterly, and the 

Midac OP-FTIR was located along the eastern 

boundary (upwind) of the survey area and the 

IMACC OP-FTIR along the western boundary 

(downwind). Each configuration consisted of three 

mirrors placed along the surface and two mirrors 

2-3
Measurement of Fugitive Emissions at a Landfill 

placed on the scissors jack. Figure 2-5 shows a picture 

of the upwind configuration used during the survey. 

Figure 2-5. Upwind Configuration from the 

Morning VRPM Survey on 01/21/04. 

During the afternoon VRPM survey, the observed 

wind direction was southwesterly. Due to software 

problems with the Midac OP-FTIR scanner, the 

IMACC OP-FTIR was set up along the eastern 

boundary to ensure that downwind data was collected. 

The OP-TDLAS system was set up along the cell’s 

western boundary to collect upwind methane concentration data. The upwind and downwind configurations consisted of three mirrors placed along the 

surface, and two mirrors placed on the scissors jack. 

2.2.3 VRPM Survey of 22 January 2004 

During the VRPM survey of 22 January, the observed 

wind direction was westerly. Due to continued technical problems with the Midac OP-FTIR scanner, the 

IMACC OP-FTIR was set up along the eastern 

boundary to ensure that downwind data was collected. 

The OP-TDLAS system was set up along the western 

boundary of the cell to collect upwind methane 

concentration data. The upwind and downwind 

configurations consisted of three mirrors placed along 

the surface, and two mirrors placed on the scissors 

jack. 

2.3 Single Path Measurement during

Leachate Pump Operation

During the afternoon of 21 January, leachate was 

being pumped from a holding pond adjacent to the 

site through a hose that extended diagonally across 

the surface of the survey area. At the request of the 

site operator, data was collected with the OP-FTIR to 

measure any emissions coming from the hose. For 

this survey, one mirror was placed directly beyond 

the leachate hose at a distance of 86.4 meters from 

the OP-FTIR instrument. 

2.4 OP-TDLAS Measurements 

The OP-TDLAS system was deployed for each day 

of the field campaign along the western boundary of 

the survey area. The OP-TDLAS configuration was 

similar to the configuration used on the western side 

of the cell during the VRPM surveys of 20 January, 

and the morning of 21 January. As mentioned previously, the OP-TDLAS system was used to provide 

upwind data for the VRPM surveys on 21 and 22 

January due to technical problems with one of the 

OP-FTIR instruments. Figure 2-6 shows a picture of 

the OP-TDLAS configuration used at the site. 

Figure 2-6. OP-TDLAS Configuration Used 

at the Site. 

2-4
Practicing Leachate Recirculation and Air Injection 

Chapter 3 

Results and Discussion 

The results from the ORS data collected at the site are 

presented in the following subsections. The measured 

methane concentrations from the HRPM and VRPM 

surveys are presented in Appendix C. 

3.1 The Horizontal RPM Results 

HRPM surveys were conducted at the site to detect 

methane hot spots. Figure 3-1 presents the reconstructed map of average surface methane concentrations (in parts per million—ppm) found during the 

HRPM survey of 21 January. The contours give 

methane concentration values (in parts per million) 

above ambient background concentrations. The red 

dot indicates the location of the OP-FTIR and scanner. The figure shows the presence of a hot spot near 

the center of the site (concentrations greater than 48 

ppm above ambient background). 

Figure 3-2 presents the reconstructed map of average 

surface methane concentrations (in parts per million) 

found during the HRPM survey done on the morning 

of 22 January. The figure shows the presence of a hot 

spot near the center of the site (concentrations greater 

than 36 ppm above ambient background). The location of the methane hot spot found during this survey 

is very similar to the results found during the HRPM 

survey of 21 January. 

Figure 3-3 presents the reconstructed map of average 

surface methane concentrations (in parts per million) 

found during the HRPM survey done on the afternoon of 22 January. During this survey, leachate was 

being pumped, as described earlier in Section 2.1. 

Figure 3-1. Average Surface Methane Concentration Contour Map from the HRPM Survey of 

01/21/04 . 

3-1
Measurement of Fugitive Emissions at a Landfill 

Figure 3-2. Average Surface Methane Concentration Contour Map from 01/22/04 Morning 

HRPM Survey. 

Figure 3-3. Average Surface Methane Concentration Contour Map from 01/22/04 Afternoon 

HRPM Survey. 

The figure shows the presence of a hot spot near the 

center of the site (concentrations greater than 26 ppm 

above ambient background), and a hot spot near the 

northwest corner (concentrations greater than 23 ppm 

above ambient background). The hot spot in the 

northwest portion of the site (which was not present 

during the previous HRPM surveys) is probably due 

to emissions from the leachate being pumped to the 

holding pond located in the northwest corner of the 

cell. 

3.2 The Vertical RPM Results 

As mentioned previously, the VRPM surveys were 

completed using two vertical configurations set up 

along the eastern and western boundary of the survey 

area. During each survey, one vertical configuration 

served as the upwind measurement of the top surface 

of the area, and the other served as the downwind 

measurement of the top surface, depending on the 

prevailing wind direction. 

3-2
Table 3-1. Moving Average of Calculated Methane 

Flux, CCF, Wind Speed, and Wind Direction for 

01/20/04 Upwind VRPM Survey. 

Relative Absolute Wind Flux Wind Wind Dir. Cycles CCF Speed (g/s) Dir.a (deg from (m/s) (deg) North) 

1 to 3 0.908 11 1.7 35 305 

2 to 4 0.960 10 1.6 43 313 

3 to 5 0.934 13 1.8 35 305 

4 to 6 0.855 17 1.8 22 292 

5 to 7 0.907 17 1.9 13 283 

6 to 8 0.916 13 1.5 1 271 

7 to 9 0.983 14 1.5 7 277 

8 to 10 0.918 18 1.4 17 287 

9 to 11 0.802 20 1.5 33 303 

10 to 12 0.888 15 1.3 29 299 

Std. 

Dev. 3.25

a Relative wind direction shown is the angle from a vector normal 

to the plane of the configuration. 

Practicing Leachate Recirculation and Air Injection 

3.2.1 VRPM Survey of 20 January 2004 

During the 20 January VRPM survey, the observed 

wind direction was west-northwest. The upwind 

configuration was located along the western boundary of the area, and the downwind configuration was 

located along the eastern boundary. Due to software 

problems with the Midac OP-FTIR system located 

along the eastern boundary of the area, downwind 

data was not available for this particular survey. 

Table 3-1 presents the calculated methane fluxes 

measured along the upwind VRPM plane. 

Figure 3-4 presents the reconstructed methane plume 

from the upwind VRPM plane. Contour lines give 

methane concentrations (in parts per million) above 

ambient background concentration. The average 

calculated methane flux from the upwind plane was 

15 g/s. The shape of the plume shown in Figure 3-4 

is not very broad vertically, and the concentrations 

found along the surface are not homogenous. This 

suggests that a methane hot spot may have been 

located in an upwind location close to the VRPM 

plane. 

Figure 3-4. Average Reconstructed Methane Plume from the 01/20/04 

Upwind VRPM Survey. 

3-3
Cycles CCF Flux 

(g/s) 

Wind

Speed 

(m/s) 

Relative 

Wind 

Dir.a 

(deg) 

Absolute

Wind Dir.

(deg from

North) 

1 to 3 0.955 18 2.9 311 221 

Measurement of Fugitive Emissions at a Landfill 

3.2.2 VRPM Surveys of 21 January 2004 

Two VRPM surveys were conducted at the site on 21 

January. During the morning VRPM survey, the 

observed winds were from the south-southeast. The 

necessary wind criteria to obtain valid flux measurements is that the observed wind direction must be ± 

70o from perpendicular to the angle of the vertical 

planes used in the measurements. A closer analysis of 

the wind data collected during the morning VRPM 

run revealed that during most of the data collection 

period, the winds failed to meet this criteria. Consequently, the data from the morning VRPM survey 

will not be reported. 

During the afternoon VRPM survey, the observed 

winds were from the southwest. Due to continuing 

software problems with the Midac OP-FTIR instrument, the IMACC OP-FTIR was set up along the 

eastern boundary of the site to ensure that downwind 

data was collected. The OP-TDLAS system was set 

up along the western boundary of the cell to collect 

upwind methane concentration data. A study was 

conducted during the current field campaign to 

compare methane concentrations measured with the 

OP-FTIR and OP-TDLAS instruments along the 

same path length. The results found favorable agreement between the two instruments. More information 

on this study can be found in Section 5.6 of this 

report. 

Tables 3-2 and 3-3 present the calculated methane 

fluxes measured along the upwind and downwind 

vertical planes during the afternoon VRPM survey, 

respectively. 

Table 3-2. Moving Average of Calculated Methane 

Flux, CCF, Wind Speed, and Wind Direction for 

01/21/04 Afternoon Upwind VRPM Survey (Collected with OP-TDLAS) 

2 to 4 0.960 15 2.5 307 217 

3 to 5 0.975 13 2.5 313 223 

4 to 6 0.996 11 2.5 305 215 

5 to 7 0.985 15 2.2 336 246 

6 to 8 0.944 15 1.6 359 269 

7 to 9 0.936 15 1.7 354 264 

8 to 10 0.967 13 1.8 328 238 

9 to 11 0.990 9.7 2.3 302 212 

10 to 12 0.997 8.7 2.1 309 219 

Std. 

Dev. 2.65 

a Relative wind direction shown is the angle from a vector normal 

to the plane of the configuration. 

Table 3-3. Moving Average of Calculated Methane 

Flux, CCF, Wind Speed, and Wind Direction for 

01/21/04 Afternoon Downwind VRPM Survey 

(Collected with OP-FTIR) 

Cycles CCF Flux 

(g/s) 

Wind 

Speed 

(m/s) 

Relative 

Wind 

Dir.a 

(deg) 

Absolute 

Wind Dir. 

(deg from 

North) 

1 to 3 0.813 9.9 2.9 317 222 

2 to 4 0.616 18 2.5 313 218 

3 to 5 0.639 21 2.5 322 227 

4 to 6 0.940 16 2.5 312 217 

5 to 7 0.981 13 2.2 337 242 

6 to 8 0.988 11 1.6 359 264 

7 to 9 0.990 10 1.8 354 259 

8 to 10 0.980 6.7 1.8 330 235 

9 to 11 0.911 4.5 2.3 306 211 

10 to 12 0.998 7.5 2.1 313 218 

Std. 

Dev. 5.16 

a Relative wind direction shown is the angle from a vector normal 

to the plane of the configuration. 

Figures 3-5 and 3-6 present the reconstructed methane plume from the upwind and downwind 21 January afternoon VRPM surveys, respectively. Contour 

lines give methane concentrations (in parts per 

3-4
Practicing Leachate Recirculation and Air Injection 

million) above ambient background concentration. the upwind survey and 10 g/s for the downwind 

The average calculated methane flux was 14 g/s for survey. 

Figure 3-5. Average Reconstructed Methane Plume from the 01/21/04 

Afternoon Upwind VRPM Survey. 

Figure 3-6. Average Reconstructed Methane Plume from the 01/21/04 

Afternoon Downwind VRPM Survey. 

3-5
Cycles CCF Flux 

(g/s) 

Wind

Speed 

(m/s) 

Relative 

Wind 

Dir.a 

(deg) 

Absolute

Wind Dir.

(deg from

North) 

1 to 3 0.966 19 4.4 16 286 

2 to 4 0.965 20 4.5 19 289 

5 to 7 0.973 21 4.2 9 279 

6 to 8 0.973 21 4.1 14 284 

7 to 9 0.976 21 4.0 7 277 

Std. 

Dev. 0.648

a Relative wind direction shown is the angle from a vector normal 

to the plane of the configuration. 

Cycles CCF Flux 

(g/s) 

Wind

Speed 

(m/s) 

Relative 

Wind 

Dir.a 

(deg) 

Absolute

Wind Dir.

(deg from

North) 

1 to 3 0.962 17 4.4 25 290 

2 to 4 0.958 20 4.5 28 293 

5 to 7 0.892 17 4.3 17 282 

Measurement of Fugitive Emissions at a Landfill 

The shape of the plume from the upwind VRPM 

survey shown in Figure 3-5 is not well developed 

vertically and not homogeneous in the horizontal 

direction, suggesting that a methane hot spot may 

have been located upwind, close to the upwind 

VRPM plane. This conclusion is supported by the 

fact that several relief wells were observed along the 

surface of the slope adjacent to the western boundary 

of the site, and elevated methane concentrations were 

measured along an OP-TDLAS beam path deployed 

in the vicinity of these wells. 

The average methane flux during the upwind VRPM 

survey (14 g/s) was higher than the average flux 

measured during the downwind VRPM survey (10 

g/s). It should be noted that these flux values are 

average values from all of the data collected during 

the survey. Tables 3-2 and 3-3 present a moving 

average of the calculated methane flux from the 

upwind and downwind configurations, respectively. 

The maximum calculated methane flux value from 

the upwind VRPM survey was 18 g/s, while at the 

same time, the maximum calculated methane flux 

value from the downwind VRPM survey was 21 g/s. 

It is apparent that, under certain wind conditions, the 

downwind VRPM survey calculated higher methane 

flux values than the upwind VRPM survey. 

The flux measurements from the upwind VRPM 

survey were probably influenced primarily by emissions from the area of elevated methane located 

directly upwind of the site. The prevailing southwesterly winds observed during the survey may have 

carried most of the emissions from the upwind 

methane hot spot through the upwind VRPM configuration (base path length of 145 m). However, the 

prevailing winds probably caused most of the emissions from this hot spot to be carried outside of the 

much shorter downwind VRPM configuration (base 

path length of 95 m). Therefore, the flux measurements from the downwind VRPM survey may have 

been only slightly influenced by emissions from the 

hot spot upwind of the site. The flux measured from 

the downwind survey is probably due to emissions 

from the methane hot spot found near the center of 

the site during the HRPM survey (see Figure 3-1). 

3.2.3 VRPM Survey of 22 January 2004 

During the 22 January VRPM survey, the observed 

wind direction was from the west-northwest. The 

OP-TDLAS system (upwind) was located along the 

western boundary of the site, and the IMACC OPFTIR (downwind) was located along the eastern 

boundary of the cell. Tables 3-4 and 3-5 present the 

calculated methane fluxes measured along the upwind and downwind vertical planes, respectively. 

Table 3-4. Moving Average of Calculated Methane 

Flux, CCF, Wind Speed, and Wind Direction for 

01/22/04 Upwind VRPM Survey (Collected with 

OP-TDLAS) 

Table 3-5. Moving Average of Calculated Methane 

Flux, CCF, Wind Speed, and Wind Direction for 

01/22/04 Downwind VRPM Survey (Collected with 

OP-FTIR). 

continued 

3-6
6 to 8 0.804 18 4.2 22 287 

7 to 9 0.908 13 4.0 15 280 

8 to 10 0.894 13 3.8 13 278 

9 to 11 0.910 16 4.2 12 277 

Std. 

Dev. 2.42

a Relative wind direction shown is the angle from a vector normal 

to the plane of the configuration. 

Measurement of Fugitive Emissions at a Landfill 

Figures 3-7 and 3-8 present the reconstructed methane plume from the upwind and downwind 22 January VRPM survey, respectively. Contour lines give 

methane concentrations (in parts per million) above 

ambient background concentration. The average 

calculated methane flux was 20 g/s for the upwind 

survey and 18 g/s for the downwind survey. 

The shape of the plume from the upwind VRPM 

survey is not well developed vertically, suggesting 

that a methane hot spot may have been located 

upwind, close to the upwind VRPM plane. This 

finding is consistent with the other upwind VRPM 

surveys conducted during this campaign along the 

western boundary of the site. 

The average methane flux during the upwind VRPM 

survey (20 g/s) was higher than the average flux 

measured during the downwind VRPM survey (18 

g/s). This is probably due to reasons similar to those 

discussed in Section 3.2.2. The prevailing northwesterly winds observed during the survey probably 

carried most of the emissions from the suspected 

upwind methane hot spot through the upwind VRPM 

configuration. However, the prevailing winds again 

caused most of the emissions from this hot spot to be 

carried outside of the much shorter downwind VRPM 

configuration. Therefore, the flux measurements from 

the downwind VRPM survey may have been only 

slightly influenced by emissions from the suspected 

hot spot upwind of the site. The flux measured from 

the downwind survey is therefore primarily due to 

emissions from the methane hot spot found near the 

center of the site during the HRPM survey (see 

Figure 3-2). 

Figure 3-7. Average Reconstructed Methane Plume from the 01/22/04 

Upwind VRPM Survey. 

3-7
Data Set Compound 

Range of Measured 

Concentration 

(ppb) 

MDL 

(ppb) 

1/20/04 VRPM Upwind Survey Ammonia 2.8 to 22 2.0 

1/21/04 VRPM Downwind Survey Ammonia 5.0 to 27 3.4 

1/21/04 VRPM Single-Path Leachate Path Survey Ammonia 3.0 to 8.9 1.9 

1/21/04 VRPM Single-Path Leachate Path Survey Methanol 11 9.3 

1/22/04 VRPM Upwind Survey Ammonia 4.4 to 37 4.1 

1/22/04 HRPM Morning Survey Ammonia 6.3 to 25 2.8 

1/22/04 HRPM Afternoon Survey Ammonia 4.8 to 28 3.2 

Measurement of Fugitive Emissions at a Landfill 

Figure 3-8. Average Reconstructed Methane Plume from the 01/22/04 

Downwind VRPM Survey. 

3.3 Results from the Single-Path Measurement during Leachate Pump Operation 

During the afternoon of 21 January, leachate was 

being pumped from a holding pond adjacent to the 

site through a hose extending diagonally across the 

surface of the survey area. One single-path measurement was taken with the OP-FTIR to determine the 

emissions coming from the hose, and the pathaveraged methane concentration was 57 ppm with a 

range of 32 to 94 ppm. These levels are approximately twice as high as concentrations found along 

comparable paths that can be derived from the HRPM 

surface data collected on the same day (see Figure 

2-6) while the leachate pump was not operating. 

3.4 VOC and Ammonia Results 

All data sets from the HRPM and VRPM surveys 

were searched for the presence of VOCs and ammonia, and the analysis did detect the presence of 

ammonia and methanol at the site. However, levels of 

measured methanol were close to the detection limits 

of the instrument. Methanol was detected only during 

the 21 January single-path measurements conducted 

while the leachate pump was operating. Table 3-6 

presents the range of measured ammonia and methanol concentrations and the minimum detection level 

(MDL) of the OP-FTIR instrument for each compound. See Section 1.3 for more information on the 

calculation of the MDL. 

Table 3-6. Average Ammonia and Methanol Concentrations Measured. 

3-8
Calculated Methane Flux 

VRPM Survey (g/s)

Upwind Downwind 

(Western) Eastern 

20 January 2004 15 N/Aa 

21 January 2004 14 10b 

22 January 2004 20 18b 

a 

b 

Downwind methane flux data from the 01/20/04 VRPM survey is 

not available due to software problems in the field. 

Calculated downwind methane flux values are lower that the 

corresponding upwind values because the entire methane plume 

was not captured by the downwind VRPM configuration. 

Practicing Leachate Recirculation and Air Injection 

Chapter 4

Conclusion

This report presents the results from a field campaign 

conducted in January 2004 at the Three Rivers Solid 

Waste Technology Center Landfill, located near 

Aiken, SC. The study used measurements from ORS 

instruments and the ORS-RPM method to characterize fugitive emissions of methane and VOCs from the 

site. 

HRPM surveys conducted on 21 and 22 January 

detected the presence of a methane hot spot near the 

center of the site. The peak concentration of this hot 

spot varied from over 26 ppm to over 48 ppm above 

ambient background concentrations. 

A HRPM survey was conducted on the afternoon of 

22 January while leachate was being pumped from a 

small holding pond in the southeast corner of the site 

to another small holding pond in the northwest corner 

of the site. This HRPM survey detected an additional 

methane hot spot near the site’s northwest corner that 

had concentrations greater than 23 ppm above ambient background levels. This hot spot is probably 

associated with emissions from the leachate being 

pumped to the holding pond located in the northwest 

corner of the cell. 

VRPM surveys were done at the site on each day of 

the field campaign. During each survey, one vertical 

configuration served as the upwind measurement, and 

the other served as the downwind measurement, 

depending on the prevailing wind direction. The use 

of an upwind VRPM configuration allowed for the 

calculation of an upwind flux value. Table 4-1 

presents the calculated methane fluxes from each 

survey. 

Table 4-1. Average Calculated Methane Fluxes 

Found During the Upwind and Downwind VRPM 

Surveys. 

The results of the VRPM surveys suggest that a 

methane hot spot may have been located directly 

upwind of the upwind VRPM configurations, on the 

western side of the top surface. The highest upwind 

methane flux value (20 g/s) occurred on 22 January. 

The observed wind speeds on this day were almost 

twice as high as those observed on 20 January (the 

prevailing wind direction on 20 January was comparable to the wind direction on 22 January), which 

may have caused increased emissions from the 

upwind hot spot. 

The downwind average methane flux values from 21 

4-1
Measurement of Fugitive Emissions at a Landfill 

and 22 January are probably lower than the corresponding upwind values because the prevailing winds 

at the time of the surveys carried a large portion of 

the plume from the upwind hot spot outside of the 

much shorter downwind VRPM configurations. 

The location of the plumes in each of the VRPM 

maps was very consistent with the prevailing wind 

direction during each survey. On 20 and 22 January, 

the west-northwesterly winds carried the plume from 

the upwind hot spot through the center of the upwind 

VRPM configurations. The west-northwesterly winds 

of 22 January carried the plume from the hot spot 

near the center of the site through the southern 

portion of the downwind VRPM configuration. On 21 

January, the southwesterly winds carried the plumes 

from the upwind hot spot and hot spot near the center 

of the site through the northern portion of the upwind 

and downwind VRPM configuration, respectively. 

The data sets from the HRPM and VRPM surveys 

were searched for the presence of VOCs and 

ammonia, and the analysis did detect ammonia and 

methanol at the site. The measured ammonia concentrations ranged from 2.8 to 37 ppm. Methanol was 

detected only during the 21 January single-path 

measurements conducted while the leachate pump 

was operating. The measured methanol concentration 

was 11 ppm, which was close to the detection limits 

of the OP-FTIR instrument. 

4-2
Instrument Measurement Calibration

Date Calibration Detail

R.M. Young Wind Monitor Wind Speed in mi/h Calibrated by Calibrated by Manufacturer 

Manufacturer 

R.M. Young Wind Monitor Wind direction in deg Calibrated by Calibrated by Manufacturer 

from North Manufacturer 

Topcon Model GTS-211D Distance 1 May 2003 Calibration of Distance: 

Theodolite Actual Distance = 50 ft 

Measured Distance = 50.6 and 50.5 ft 

Topcon Model GTS-211D Angle 21 May 2003 Calibration of Angle: 

Theodolite Actual Angle = 360° 

Measured Angle = 359°41N18O and 

359°59N55O

Practicing Leachate Recirculation and Air Injection 

Chapter 5

Quality Assurance/Quality Control

5.1 Equipment Calibration cedures and frequency are listed in Table 5-1 and 

As stated in the ECPD Optical Remote Sensing further described in the text. 

Facility Manual (U.S. EPA, 2004), all equipment is 

calibrated annually or cal-checked as part of standard As part of the preparation for this project, a Category 

operating procedures. Certificates of calibration are III Quality Assurance Project Plan (QAPP) was 

kept on file. Maintenance records are kept for any prepared and approved for each separate field camequipment adjustments or repairs in bound project paign. In addition, standard operating procedures 

notebooks that include the data and description of were in place during the field campaign. 

maintenance performed. Instrument calibration proTable 5-1. Instrumentation Calibration Frequency and Description. 

5.2 Assessment of DQI Goals completeness are listed in Table 5-2. More informaThe critical measurements associated with this tion on the procedures used to assess DQI goals can 

project and the established data quality indicator be found in Section 10 of the ECPD Optical Remote 

(DQI) goals in terms of accuracy, precision, and Sensing Facility Manual (U.S. EPA, 2004). 

5-1
Measurement Analysis Method Accuracy Precision Completeness 

Analyte PIC OP-FTIR: Nitrous Oxide 

Concentrations 

±25%/15%/10%a ±10% 90% 

Ambient Wind Speed Met. heads side-by-side comparison in the field ±1 m/s ±1 m/s 90% 

Ambient Wind Direction Met. heads side-by-side comparison in the field ±10° ±10° 90% 

Distance Theodolite ±1 m ±1 m 100% a The accuracy acceptance criterion of ±25% is for path lengths of less than 50m, ±15% is for path lengths between 50 and 100m, and ±10% 

is for path lengths greater than 100m. 

Measurement of Fugitive Emissions at a Landfill 

Table 5-2. DQI Goals for Instrumentation. 

5.2.1 DQI Check for Analyte PIC Measurement 

The precision and accuracy of the analyte pathintegrated concentration (PIC) measurements was 

assessed by analyzing the measured nitrous oxide 

(N2O) concentrations in the atmosphere. A typical 

background atmospheric concentration for N2O is 

about 315 ppb. This value may fluctuate due to 

seasonal variations in N2O concentrations or elevation of the site. 

The precision of the analyte PIC measurements was 

evaluated by calculating the relative standard deviation of each data subset. A subset is defined as the 

data collected along one particular path length during 

one particular survey in one survey sub-area. The 

number of data points in a data subset depends on the 

number of cycles used in a particular survey. 

The accuracy of the analyte PIC measurements was 

evaluated by comparing the calculated N2O concentrations from each data subsets to the background 

value of 315 ppb. The number of calculated N2O 

concentrations that failed to meet the DQI accuracy 

criterion in each data subset was recorded. 

Overall, 43 data subsets were analyzed from this field 

campaign. Based on the DQI criterion set forth for 

precision of ±10%, each of the 43 data subsets were 

found to be acceptable. The range of calculated 

relative standard deviations for the data subsets from 

this field campaign was 1.1 to 6.1 ppbm, which 

represents 0.35% to 1.9% RSD. 

Each data point (calculated N2O concentration) in the 

43 data subsets were analyzed to assess whether or 

not it met the DQI criterion for accuracy of ±25% 

(315 ± 79 ppb) for path lengths less than 50 meters, 

±15% (315 ± 47 ppb) for path lengths between 50 

and 100 meters, and ±10% (315 ± 32 ppb) for path 

lengths greater than 100 meters. A total of 306 data 

points were analyzed, and 294 of the points met the 

DQI criteria for accuracy for a completeness of 96%. 

5.2.2 DQI Checks for Ambient Wind Speed 

and Wind Direction Measurements 

Section 10 of the ECPD Optical Remote Sensing 

Facility Manual (U.S. EPA, 2004) states that the DQI 

goals for precision and accuracy of the R.M. Young 

meteorological heads are assessed by collecting 

meteorological data for 10 min with the two heads set 

side-by side. This was not done prior to the current 

field campaign because this DQI procedure had not 

been implemented at the time of the study. However, 

checks for agreement of the wind speed and wind 

direction measured from the two heads (at heights of 

2 m and 10 m) were done in the field during data 

collection. Although it is true that some variability in 

the parameters measured at both levels should be 

expected, this is a good first-step check for assessing 

the performance of the instruments. Another check is 

done in the field by comparing the measured wind 

5-2
Practicing Leachate Recirculation and Air Injection 

direction to the forecasted wind direction for that 

particular day. 

5.2.3 DQI Check for Precision and Accuracy 

of Theodolite Measurements 

Although calibration of this instrument did not occur 

immediately prior to the current field campaign, the 

theodolite was originally calibrated by the manufacturer prior to being received by the U.S. EPA. Additionally, there are several internal checks in the 

theodolite software that prevent data collection from 

occurring if the instrument is not properly aligned on 

the object being measured or if the instrument has not 

been balanced correctly. When this occurs, it is 

necessary to reinitialize the instrument to collect data. 

DQI checks were performed on the theodolite at a 

field site near Chapel Hill, NC, prior to the current 

field campaign. The calibration of distance measurement was done using a tape measure to compare the 

actual distance to the measured distance. This check 

was duplicated to test the precision of this measurement. The actual distance measured was 15.2m. The 

measured distance during the first test was 15.4m, 

and the measured distance during the second test was 

15.4m. The results indicate the accuracy (1.3% bias 

for test one and two) and precision (0% RSD) of the 

distance measurement fell well within the DQI goals. 

The check to test the precision and accuracy of the 

angle measurement was done by placing two mirror 

targets approximately 180 degrees apart. The theodolite was placed in the middle of the imaginary circle 

formed by the two mirrors. The actual angle was 

360°. The angle measured during the first test was 

359°41N18O, and the angle measured during the 

second test was 359°59N55O. The results indicate the 

accuracy and precision of the angle measurement fell 

well within the DQI goals. 

5.3 QC Checks of OP-FTIR Instrument 

Performance 

Several checks should be performed on the OP-FTIR 

instrumentation prior to deployment to the field, and 

during the duration of the field campaign. More 

information on these checks can be found in MOP 

6802 and 6807 of U.S. EPA, 2004. At the time of the 

current field campaign, the procedures and schedule 

of QC checks were still being developed. Consequently, only a select set of checks were performed 

on both OP-FTIR instruments prior to deployment 

and during the field campaign. 

Prior to deployment (15 January), the single beam 

ratio, baseline stability, electronic noise, saturation, 

linearity, and random baseline noise tests were 

performed on the IMACC OP-FTIR instrument, and 

the single beam ratio, signal-to-noise, ZPD stability, 

and saturation tests were performed on the Midac 

instrument. The results of the tests indicated that both 

instruments were operating within the acceptable 

criteria range. 

On 20 January 2004, the single beam ratio, saturation, 

electronic noise, linearity, and random baseline noise 

tests were performed on both OP-FTIR instruments. 

The results of these tests indicated that the instruments were operating within the acceptable criteria 

range. 

In addition to the QC checks performed on the OPFTIR, the quality of the instrument signal (interferogram) was checked constantly during the field campaign. This was done by ensuring that the intensity of 

the signal is at least five times the intensity of the 

stray light signal (the stray light signal is collected as 

background data prior to actual data collection and 

measures internal stray light from the instrument 

itself). In addition to checking the strength of the 

signal, checks were done constantly in the field to 

ensure that the data were being collected and stored 

to the data collection computer. During the campaign, 

a member of the field team constantly monitored the 

data collection computer to make sure these checks 

were completed. 

5.4 Validation of Concentration Data 

Collected with the OP-FTIR 

During the analysis of the OP-FTIR data, a validation 

procedure was performed to aid in identifying the 

5-3
Measurement of Fugitive Emissions at a Landfill 

presence of ammonia and methanol in the dataset. analyzed concentration data, mirror path lengths, and 

This validation procedure involves visually compar- wind data. The results of this audit found no probing an example of the measured spectra to a labora- lems with the accuracy of the input files created. 

tory-measured reference spectrum. 

5.6 OP-TDLAS Instrument 

Figure 5-1 shows an example of a validation done The development of calibration and standard operatusing a spectrum collected during the 21 January ing procedures for the OP-TDLAS system has resingle-path measurements conducted while the sulted in a major improvement in the data collection 

leachate pump was operating. Ammonia and metha- process. More information on collecting emissions 

nol were detected in this particular spectrum. The measurements with the OP-TDLAS can be found in 

ammonia and methanol features can be seen in the MOP 6811 of U.S. EPA, 2004.

measured field spectrum (blue trace). Classical least 

squares (CLS) analysis performed on this spectrum The results of the current field campaign present 

resulted in determinations of 10.6±4.7 ppb of metha- methane concentrations measured with the OP-FTIR 

nol, and 8.86±0.93 ppb of ammonia. The uncertainty instrument and the OP-TDLAS system. In order to 

value is equal to three times the standard error in the evaluate the comparability of measurements from the 

regression fit of the measured spectrum to a cali- two instruments, an experiment was conducted during 

brated reference spectrum, propagated to the concen- this field campaign to compare methane concentratration determination. tions measured with the OP-TDLAS system and the 

IMACC OP-FTIR. The two instruments were deployed side-by-side at a location near the western 

boundary of the site, and aimed at an identical mirror 

located at a distance of 89 m. Methane concentration 

data were collected with each instrument for a period 

of 30 min. The OP-FTIR collected data at the same 

resolution (0.5 cm-1) used in the current field campaign. Figure 5-2 shows that methane concentrations 

measured with the OP-TDLAS were slightly higher 

(3%) than concentrations measured with the OPFTIR instrument. The results of this experiment show 

that the methane concentration measurements made 

from the OP-FTIR and OP-TDLAS instruments can 

be used to compare upwind and downwind data 

collected during this study. 

5.7 Difficulties Encountered 

During the course of the field campaign, the project 

encountered some difficulties. These included software problems with the scanner used to control the 5.5 Internal Audit of Data Input Files Midac OP-FTIR, difficulty in precisely time synchroAn internal audit was performed by the ARCADIS nizing the data collected from both VRPM configuraField Team Leader on a sample of approximately tions, and geographic barriers at the site that limited 

10% of the data from the field campaign. The audit the sizes of the configurations used in the study.

investigated the accuracy of the input files used in 

running the RPM programs. The input files contain On 20 January, the Midac OP-FTIR instrument was 

Figure 5-1. Comparison of a spectrum measured 

at the site (top trace) to the reference spectra of 

methanol (middle) and ammonia (bottom). 

5-4
Practicing Leachate Recirculation and Air Injection 

Figure 5-2. Comparison of Methane Concentrations Measured with the OP-TDLAS and OP-FTIR 

Instruments. 

set up on the downwind side of the site. However, 

problems with the software used to control the 

scanner used with this instrument prevented downwind flux data from being collected on this day. Software problems continued with this instrument, and 

the OP-TDLAS instrument was needed to collect flux 

data for the duration of the project. 

Another problem encountered was difficulty in 

precisely time synchronizing the data collected from 

the upwind and downwind VRPM configurations. 

Although the internal clocks on the data collection 

computers (used in the two VRPM configurations) 

were synchronized before data collection began, it 

was difficult to perfectly synchronize the starting and 

ending times of the data loops due to differences in 

the initialization and data collection times of the 

OP-TDLAS and OP-FTIR instruments. This problem 

made it difficult to compare short-term temporal 

variations in the upwind and downwind flux values 

collected during the VRPM surveys. 

The geographical features of the site limited the size 

and location of the configurations used for data 

collection. The surface of the site along the eastern 

boundary was extremely uneven. This limited the 

distance of the VRPM configuration on the eastern 

side of the site to 95 m, which was much shorter than 

the VRPM configuration on the western side of the 

site (145 m). In cases where the winds were not close 

to perpendicular to the VRPM configurations, the 

shorter VRPM configuration along the eastern boundary of the survey area may not have captured the 

entire methane plume from the survey area. We 

suspect that this limitation contributed to the fact that 

the upwind flux values were sometimes greater than 

the downwind flux values. This problem could have 

been overcome if it had been possible to collect data 

for additional days when the prevailing wind direction had an eastern component (the longer western 

boundary would have become the downwind vertical 

plane in this case). 

Despite these difficulties, the project was successful 

in producing surface methane concentration contour 

maps, and isolated methane flux values, especially 

from the western slope of the survey area (which 

were relatively consistent throughout the duration of 

the campaign). 

5-5
Measurement of Fugitive Emissions at a Landfill 

5-6 
Practicing Leachate Recirculation and Air Injection 

Chapter 6

References

ASTM, 1999. American Society for Testing and Materials 

Standard Practice E1982-98, Standard Practice for 

Open-Path Fourier Transform Infrared (OP/FT-IR) 

Monitoring of Gases and Vapors in Air; March. 

Hashmonay, R.A., M.G. Yost, D.B. Harris, and E.L. 

Thompson, 1998. Simulation study for gaseous fluxes 

from an area source using computed tomography and 

optical remote sensing, in SPIE, The International Society 

for Optical Engineering, Bellingham, WA, 3534, 405–410. 

Hashmonay, R.A., M.G. Yost, and C. Wu, 1999. Computed tomography of air pollutants using radial scanning 

path-integrated optical remote sensing, Atmos. Environ., 

33, 267–274. 

Hashmonay, R.A., and M.G. Yost, 1999. Innovative 

approach for estimating fugitive gaseous fluxes using 

computed tomography and remote optical sensing techniques, J. Air Waste Manage. Assoc., 49, 966–972. 

Hashmonay, R.A., D.F. Natschke, K.Wagoner, D.B. 

Harris, E.L.Thompson, and M.G. Yost, 2001. Field evaluation of a method for estimating gaseous fluxes from area 

sources using open-path Fourier transform infrared, 

Environ. Sci. Technol., 35, 2309–2313. 

Hashmonay, R.A., K. Wagoner, D.F. Natschke, D.B. 

Harris, and E.L. Thompson, 2002. Radial computed 

tomography of air contaminants using optical remote 

sensing, in Proceedings of the AWMA 95th Annual 

Conference and Exhibition, VIP-110, Air & Waste 

Management Association, Pittsburgh, PA. 

Platt, U., 1994. Differential optical absorption spectroscopy (DOAS), in Air Monitoring by Spectroscopic Techniques, Chemical Analysis Series, Vol. 127, John Wiley & 

Sons, Inc. pp. 27–84. 

Wu, C., M.G. Yost, R.A. Hashmonay, and D.Y. Park, 

1999. Experimental evaluation of a radial beam geometry 

for mapping air pollutants using optical remote sensing 

and computed tomography, Atmos. Environ., 33, 

4709–4716,. 

U.S. EPA, 1999. Compendium Method TO-16: Long-Path 

Open-Path Fourier Transform Infrared Monitoring of 

Atmospheric Gases; EPA-625/R-96/101b (NTIS PB99­

172355), U.S. Environmental Protection Agency, Center 

for Environmental Research Information-Office of Research and Development: Cincinnati, Ohio, January. 

U.S. EPA, 2004. ECPD Optical Remote Sensing Facility 

Manual, EPA-600/Q-04/088, National Risk Management 

Research Laboratory, Air Pollution Prevention and Control Division, Research Triangle Park, NC, August. 

6-1
Measurement of Fugitive Emissions at a Landfill 

6-2 
Mirror 

Number 

Distance 

(m) 

Horizontal 

Angle from 

North 

(deg) 

Vertical 

Anglea 

(deg) 

1 48.2 184 0 

2 89.2 180 0 

3 144 179 0 

4 145 178 2 

5 146 177 5 a Vertical angle shown is the angle from horizontal (positive values 

indicate elevation from the horizontal, negative values indicate 

descent from the horizontal). 

Mirror 

Number 

Distance 

(m) 

Horizontal 

Angle from 

North 

(deg) 

Vertical 

Anglea 

(deg) 

1 45.0 184 0 

2 93.4 187 0 

3 94.6 186 4 a Vertical angle shown is the angle from horizontal (positive values 

indicate elevation from the horizontal, negative values indicate 

descent from the horizontal). 

Mirror 

Number 

Distance 

(m) 

Horizontal 

Angle from 

North 

(deg) 

Vertical 

Anglea 

(deg) 

1 32.6 182 0 

2 62.3 184 0 

3 94.4 185 0 

4 94.9 184 1 

5 95.6 185 5 a Vertical angle shown is the angle from horizontal (positive values 

indicate elevation from the horizontal, negative values indicate 

descent from the horizontal). 

Mirror 

Number 

Distance 

(m) 

Horizontal 

Angle from 

North 

(deg) 

Vertical 

Anglea 

(deg) 

1 48.2 184 0 

2 89.2 180 0 

3 144 179 0 

4 145 178 2 

5 146 177 5 a Vertical angle shown is the angle from horizontal (positive values 

indicate elevation from the horizontal, negative values indicate 

descent from the horizontal). 

Practicing Leachate Recirculation and Air Injection 

Appendix A

OP-FTIR Mirror Coordinates

Table A-1. Distance and Angular Coordinates of 

Mirrors Used in the 01/20/04 Upwind VRPM 

Survey. 

Table A-2. Distance and Angular Coordinates of 

Mirrors Used in the 01/20/04 Downwind VRPM 

Survey. 

Table A-3. Distance and Angular Coordinates of 

Mirrors Used in the 01/21/04 Upwind VRPM 

Survey. 

Table A-4. Distance and Angular Coordinates of 

Mirrors Used in the 01/21/04 Downwind VRPM 

Survey. 

A-1
Mirror 

Number 

Distance 

(m) 

Horizontal Angle from North 

(deg) 

1 107 187 

2 69.1 191 

3 117 199 

4 120 209 

5 39.0 208 

6 77.3 211 

7 82.3 223 

8 45.2 236 

9 58.5 253 

Mirror 

Number 

Distance 

(m) 

Horizontal 

Angle from 

North 

(deg) 

Vertical 

Anglea 

(deg) 

1 32.6 173 0 

2 58.5 175 0 

3 94.9 170 0 

4 95.9 169 2 

5 96.6 169 6 a Vertical angle shown is the angle from horizontal (positive values 

indicate elevation from the horizontal, negative values indicate 

descent from the horizontal). 

Measurement of Fugitive Emissions at a Landfill 

Table A-5. Distance and Angular Coordinates of 

Mirrors Used in the 01/21/04 HRPM Survey. 

Mirror 

Number 

Distance 

(m) 

Horizontal Angle from North 

(deg) 

1 59.6 109 

2 42.7 119 

3 89.1 137 

4 39.0 150 

5 84.1 151 

6 118 152 

7 113 161 

8 73.9 168 

9 111 170 

Table A-6. Distance and Angular Coordinates of 

Mirrors Used in the 01/22/04 HRPM Survey. 

Table A-7. Distance and Angular Coordinates of 

Mirrors Used in the 01/22/04 Downwind VRPM 

Survey. 

A-2
Mirror 

Number 

Distance 

(m) 

Horizontal 

Angle from 

North 

(deg) 

Vertical

Anglea 

(deg)

1 47.7 184 0 

2 88.5 181 0 

3 144 179 0 

4 145 179 3 

5 146 177 5 a Vertical angle shown is the angle from horizontal (positive values 

indicate elevation from the horizontal, negative values indicate 

descent from the horizontal). 

Practicing Leachate Recirculation and Air Injection 

Appendix B 

OP-TDLAS Configuration Path Lengths 

Table B-1. Distance and Angular Coordinates of 

Mirrors Used in the OP-TDLAS Configuration. 

B-1
Measurement of Fugitive Emissions at a Landfill 

B-2
Cycle 

Mirror Number 

1 2 3 4 5 

1 23.5 24.4 19.7 11.3 11.7 

2 17.0 16.3 22.3 14.1 8.97 

3 8.90 18.2 14.8 8.6 7.05 

4 5.56 16.1 25.9 13.6 7.47 

5 18.2 22.2 30.2 9.7 11.3 

6 14.1 14.3 16.2 10.3 14.9 

7 25.1 26.1 22.5 12.2 9.56 

8 34.3 25.0 23.3 15.7 8.05 

9 15.0 26.6 26.6 14.7 10.5 

10 20.3 34.7 24.4 21.3 22.0 

11 29.6 32.7 36.8 16.1 14.4 

12 42.1 30.0 22.6 15.4 7.96 

Cycle 

Mirror Number 

1 2 3 4 5 

1 28.8 15.8 9.61 7.38 7.21 

2 8.81 5.76 4.32 4.04 4.92 

3 6.30 5.90 6.55 7.10 3.35 

4 6.52 4.67 4.13 4.36 4.70 

Practicing Leachate Recirculation and Air Injection 

Appendix C

Methane Concentrations

Table C-1. Methane Concentrations (in PPM) 

found during the 01/20/04 Upwind VRPM Survey. 

5 

6 

9.27 

10.1 

6.75 

10.5 

6.33 

12.4 

6.88 

8.47 

5.86 

5.71 

7 13.1 7.33 5.91 7.08 5.64 

8 

9 

8.25 

6.79 

4.73 

5.89 

4.00 

3.71 

4.44 

3.77 

3.71 

4.69 

10 6.81 5.81 6.70 4.00 4.20 

11 5.79 4.98 3.62 3.00 2.94 

12 12.1 10.4 8.43 6.85 3.82 

13 12.8 10.4 11.0 6.84 4.12 

14 7.54 15.0 13.1 5.94 5.16 

15 15.1 8.40 8.60 4.94 7.69 

16 31.1 20.4 11.8 12.7 11.0 

17 19.0 14.6 7.21 7.83 8.36 

18 33.3 12.3 8.96 5.49 4.76 

19 8.91 8.65 9.01 5.95 4.38 

20 18.9 7.65 12.7 6.01 5.24 

21 12.2 11.2 6.69 4.27 9.20 

22 23.0 23.1 14.8 12.6 6.43 

Table C-2. Methane Concentrations (in PPM) 

found during the 01/21/04 Upwind VRPM Survey. 

23 

24 

32.3 

29.8 

20.7 

21.4 

18.9 

16.7 

10.4 

10.3 

8.98 

12.3 

25 32.6 17.9 11.2 6.71 5.82 

26 

27 

21.5 

12.6 

15.7 

7.64 

9.10 

19.3 

11.8 

9.90 

5.32 

8.18 

28 19.8 16.0 13.0 7.47 6.42 

29 15.9 14.2 9.68 6.57 6.33 

30 24.9 16.1 14.2 8.84 9.37 

C-1
Cycle 

Mirror Number 

1 2 3 4 5 6 7 8 9 

1 

2 

12.2 

19.7 

20.6 

22.3 

29.4 

24.0 

15.1 

8.50 

34.5 

35.1 

30.5 

20.0 

22.5 

26.6 

23.8 

17.2 

19.5 

Measurement of Fugitive Emissions at a Landfill 

Table C-3. Methane Concentrations (in PPM) 

found during the 01/21/04 Downwind VRPM 

Survey. 

Mirror Number 

Cycle 1 2 3 4 5 

1 17.4 20.9 16.4 14.5 10.5 

2 18.2 23.7 13.9 10.3 10.6 

3 12.2 9.36 14.2 11.3 9.06 

4 6.86 13.5 21.5 12.4 15.6 

5 25.1 20.5 17.8 15.2 10.2 

6 6.36 21.9 15.7 16.0 10.9 

7 19.8 26.0 15.4 9.04 8.61 

8 10.2 13.4 16.7 15.8 15.3 

9 29.7 25.2 12.9 8.33 7.73 

10 15.8 28.4 21.7 14.1 7.06 

11 16.6 9.37 16.0 11.9 5.67 

12 12.9 19.9 14.4 16.0 16.2 

13 30.6 25.9 14.5 8.22 7.58 

14 15.5 15.7 14.7 10.5 8.13 

15 20.9 12.7 16.2 13.4 13.1 

16 14.7 10.2 19.5 9.88 13.2 

17 20.9 28.0 22.0 15.8 11.1 

18 26.3 12.5 10.8 18.1 10.8 

19 24.9 13.3 20.7 17.1 3.23 

20 16.4 21.8 25.0 17.4 9.90 

21 18.6 20.6 22.8 10.0 7.43 

22 34.7 24.5 11.6 11.8 7.88 

23 29.5 30.5 17.1 11.2 9.37 

24 39.6 23.1 14.8 18.9 13.4 

Table C-4. Methane Concentrations (in PPM) found during the 01/21/04 HRPM Survey. 

C-2
Cycle 

Mirror Number 

1 2 3 4 5 

1 8.48 10.01 12.80 10.65 6.78 

2 11.77 9.86 11.56 9.04 5.15 

3 10.36 9.03 11.48 8.39 7.17 

4 9.54 11.16 10.83 11.32 9.80 

5 18.01 17.60 13.18 8.60 6.69 

6 9.53 9.97 9.23 8.89 5.69 

7 9.34 13.07 15.15 10.29 9.54 

8 11.78 9.48 14.27 6.47 6.25 

9 11.68 13.42 15.82 8.79 4.58 

10 6.58 13.65 15.44 10.13 9.89 

11 17.05 11.29 13.13 8.97 6.52 

Practicing Leachate Recirculation and Air Injection 

Table C-5. Methane Concentrations (in PPM) 

found during the 01/22/04 Downwind VRPM 

Survey. 

Table C-6. Methane Concentrations (in PPM) found during the 01/22/04 HRPM Survey. 

Mirror Number 

Cycle 1 2 3 4 5 6 7 8 9 

1 22.3 35.9 27.3 24.1 15.0 32.7 15.8 13.5 22.6 

2 23.9 16.6 25.4 24.4 14.5 28.6 13.3 20.5 16.9 

3 20.9 22.7 25.7 21.5 14.6 24.8 11.2 13.4 16.5 

4 19.5 21.4 29.4 24.8 13.9 28.0 16.7 22.8 22.1 

5 25.4 19.1 30.0 24.4 12.4 24.3 21.4 16.7 26.0 

6 24.3 23.9 26.8 20.4 14.7 17.0 13.2 22.5 13.9 

7 20.4 17.9 19.3 19.6 13.2 18.2 14.4 9.95 17.2 

8 19.5 15.0 16.8 18.7 9.14 17.0 13.1 11.6 18.2 

9 22.9 21.6 27.9 24.6 21.5 19.3 13.4 14.8 20.4 

10 22.0 20.7 21.6 22.7 23.4 24.8 9.90 10.3 9.34 

11 18.2 12.4 21.7 19.1 10.3 28.1 11.1 15.0 18.1 

C-3