1

Landfills NSPS Technical Meeting

U.S. EPA, Research Triangle Park, NC

October 22, 2012

Agenda: Attachment A

Presentations: Attachment B

Attendees: 

Hillary Ward, EPA/OAQPS

Peter Tsirigotis, EPA/OAQPS

Rick Vetter, EPA/OAQPS

Tom Driscoll, EPA/OAQPS

Susan Thorneloe EPA/ORD

Eben Thoma, EPA/ORD

Richard Shores, EPA/ORD

Larry Sorrels, EPA/OAQPS

Joanna Swanson, EPA/OAQPS

Kirt Cox, EPA/OAQPS

Tom Frankiewicz, EPA/LMOP

Shaun Ragnauth, EPA/OAP/CCD

Alex MacPherson, EPA/OAQPS

David Solomon, EPA/OAQPS

Kathy Kaufman EPA/OAQPS

Jason Dewees, EPA/OAQPS

Robin Segall, EPA/OAQPS

Morton Barlaz, NC State University

Frank Caponi, LA County Sanitation Districts

Frank Franciosi, US Composting Council

Jeff Chanton, Florida State University

Amy Banister, Waste Management

Kelly Kerry, Waste Management

Roger Green, Waste Management

Angela Marconi, DSWA

Niki Wuestenberg, Republic Services

Ron Strube, Veolia Environmental Services

Tomas Carbonell, Environmental Defense Fund

Peter Zalzal, Environmental Defense Fund

Ruth Mead, ERG

Joe Fanjoy, ERG

On the phone:

Tavara Culpepper, EPA/OECA

Bob Harris, Environmental Defense Fund

David Marshall, Clean Air Task Force

Ellen Baum, Clean Air Task Force

Elaine Matthews, NASA, Goddard Institute for 

Space Science

Pat Sullivan, SCS Engineers

Reynaldo Crooks, California Air Resources 

Board

Rich Boyd, California Air Resources Board

Scott Walker, CalRecycle

Nick Lapis, Californians Against Waste

10:30 AM Opening Remarks

Peter Tsirigotis –USEPA Sector Policies and Programs Division

• EPA is interested in individual perspectives on the issues that will be discussed today.

• Input will enable EPA to write the best and most effective regulations for landfills.

• An EPA representative asserted that the Agency was not attempting to build consensus.

10:45 AM Early Collection System Installation Incentives: Design and Operations

Angela Marconi- Delaware Solid Waste Authority

Following the presentation, attendees reiterated and expanded on the challenges of early 

collection:
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• A few States are requiring owners/operators to meet the wellhead temperature and 

oxygen/nitrogen requirements, even if the landfill has installed collection and control 

systems or energy projects early and is not yet subject to the NSPS.

• Maintaining negative pressure, as required by the NSPS, is generally not an issue.

• Compliance with NSPS oxygen and temperature requirements can be difficult in various 

early control situations:

oLow-flow wells in areas where little gas is generated can be difficult to operate 

while maintaining compliance with the oxygen and temperature requirements.

oIf gas is collected from the leachate system, the oxygen limit is not relevant 

because the leachate system is not pulling gas through the landfill waste mass. 

oWhen installing or expanding the gas collection and control system in active 

areas, landfills typically use horizontal collectors for early collection. (Vertical 

wells are not installed until later with the area is full.) The fresh waste on top of 

the horizontal collector is shallow, potentially resulting in oxygen being pulled 

into the system. 

• Gas collected from early horizontal collectors or low-flow areas may have low methane 

content and therefore be more difficult and costly to control. Flares may require 

supplemental fuel, which is costly; and landfill gas energy developers are not interested 

in inconsistent flows or low-quality gas.

• Site conditions and gas generation determine how the landfill owner/operator manages 

the early collection area. It takes time to ramp up to a full NSPS collection system. 

Application of NSPS collection system requirements including the temperature and 

oxygen limits is a disincentive to early gas collection and beneficial use projects. 

The NSPS allows case-by-case approval of higher operating values (HOVs) for wellhead 

parameters. The burden of approval is on State/local authorities.

• Authorities are not sure how to respond to the requests. 

• When there are responses, there is inconsistency across States. 

• Waste Management has provided documentation and data to justify HOVs, but some

requests for HOVs are still outstanding.

• One attendee stated that State/local authorities need guidance on how to approve requests 

for HOVs.

The following items concerning earlier installation of controls and earlier expansion were 

discussed: 

• Provide flexibility in collection and control requirements and operating parameters for 

areas of the landfill that have early control.

• Remove the oxygen and temperature requirements. 

• Release leachate systems from the oxygen and temperature requirements.

• EPA should examine the landfill holistically, rather than isolating only the early 

collection/control. 

• Performance (as reflected by surface monitoring rather than operating parameter limits) 

should be the key in managing gas in early collection areas.

• If EPA were to require earlier collection, industry would need flexibility as the system is 

installed and operated.
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• Provide flexibility regarding when to pull gas from the early collection area. For 

example, operating the collection and control system intermittently (e.g., every other day) 

might allow the landfill to collect the gas without exceeding the oxygen operating 

parameter.

• In response to a question about whether early collection and beneficial use projects are 

more feasible at certain landfills, industry responded that the feasibility of early 

collection depends on the landfill site, climate, waste characteristics, and also on what 

incentives for beneficial use projects are available. The recent trend toward less organics 

in waste would reduce methane generation and could make early collection more 

difficult. 

An EPA representative explained that it could be difficult to remove the oxygen and temperature 

requirements. The oxygen requirements are intended to prevent fires. The temperature 

requirements are intended to keep the methanogens alive. EPA is concerned that higher 

temperature would kill methanogens and waste decomposition would cease.

One attendee stated that the NSPS should address landfill “fires” such as those in landfills in 

Ohio and California. He said that CalRecycle expects to have data and suggestions on this issue.

An attendee indicated that the reason for the temperature and oxygen/nitrogen limits in the rule 

was primarily to prevent landfill fires. Several attendees representing landfills and the waste 

management industry explained that they view the wellhead limits as unnecessary because 

landfill owner/operators are already motivated to prevent fires. Fires could damage gas collection 

and control systems or the landfill liner. Many large landfills already have beneficial use projects 

in place and do not want fires to damage these projects. They also pointed out that the NSPS 

requires installation of another well if wellhead monitoring parameter exceedances are not 

corrected within 15 days, but that adding a well can be counterproductive where there is a fire.

An EPA representative indicated that fires and operating problems may be more common at 

smaller municipal landfills that do not have the same level of resources or knowledge of how

situations encountered at other landfills have been successfully addressed.

11:30 AM Surface Monitoring Requirements 

Renaldo Crooks- California Air Resources Board, Scott Walker- CalRecycle, and 

Pat Sullivan –SCS Engineers

Two presentations described California’s landfill surface monitoring requirements and compared

them to the surface monitoring requirements in the landfills NSPS.

Discussion:

One attendee asserted that he would soon have 1 year of data on landfills subject to both the CA 

rule and the NSPS. He offered to share that data with EPA.

An EPA representative stated that EPA would consider and would be interested in data, in 

particular to determine whether the CA integrated sampling requirement results in better 

emission control. EPA would also like perspectives on moving away from oxygen and 

temperature wellhead requirements and relying on enhanced surface monitoring instead.
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Because the CA rule requires monitoring of every cover penetration, the serpentine path has 

closer intervals (25 ft. vs. ~100 ft.), and there is additional integrated monitoring, industry 

attendee estimates that surface monitoring under CA rule is 4-6 times more expensive than 

monitoring under the landfills NSPS. He noted that one landfill in California has over 1,000 

penetrations. He believes that EPA should examine cost when considering the NSPS monitoring 

options.

Regarding when to install controls, the CA rule does not specify a date by which collection must 

be in place, but all areas, regardless of the age of the waste, must be monitored and must meet 

the surface methane limits. On the other hand, the landfills NSPS does specify when you have to 

install and expand controls.

One attendee noted that under the NSPS, you might have to “turn down” the gas mover 

equipment in order to meet the wellhead monitoring parameters (oxygen and temperature). But, 

under the CA rule, landfills are not required to meet wellhead monitoring parameters, and must 

only ensure that there is negative pressure at the wellhead.

California’s landfill surface monitoring requirements were developed in response to Assembly 

Bill (AB) 32, which set a CA greenhouse gas emissions reduction goal for 2020 and directed 

ARB to begin early actions to reduce greenhouse gases. Early actions specifically identified

emissions from landfills. The immediate goal was to achieve additional landfill reductions 

beyond current CA laws and the EPA NSPS.

One attendee noted that this early control measure for landfills represents the “low hanging fruit” 

in terms of identifying emissions. He stated that the monitoring requirements are the result of 

negotiations, and that it was not based on what would be the most protective or ultimate 

approach. A CA representative indicated that through the CA rule they are collecting data on 

measurements above 200 ppmv and will analyze the data and determine if further requirements 

for landfills are needed.

Another attendee believes that using the data that were available and the South Coast rule served 

as a solid basis for the California monitoring requirements and that the process and negotiations 

did not “shortchange” the monitoring requirements. He acknowledged that a second phase of 

further requirements was always envisioned.

12:15 AM BREAK FOR LUNCH

1:00 PM Updated k values based on using more detailed landfill gas collection and 

header pipe data 

Dr. Morton Barlaz- NC State University 

Research was presented on developing updated k values.

Results show that the best fits are at Lo=100 and k value is higher than 0.4. This is the same Lo 

value as AP-42, but the k rate found in the study is faster than typically used. Results are 

empirical based on collected gas measurements as well as estimated gas collection efficiencies 
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for each landfill area based on scientific judgment. Results do not account for oxidation (that is, 

where collection = 0, there is still methane oxidation through the cover soil.) 

One attendee asked whether results would apply to arid areas. The presenter responded that he 

did not get data from arid landfills and that he could not extrapolate his data to arid landfills and 

the results that would occur relative to the arid k value of 0.02.

The presenter thinks that LandGEM should stop referring to Lo as “methane generation 

potential” because in the model, it accounts for other factors that affect methane 

emissions/generation: temperature, moisture, waste composition changes, etc.

One attendee from an environmental group asked about the difference between the IPCC 

methodology and LandGEM. The presenter responded that the equations are the same, but they 

use different terminology. IPCC uses Degradable Organic Carbon (DOC) times the percent of 

carbon that degrades. IPCC defaults result in Lo=86-88.

1:45 PM ORS and Cavity Ring Down – Which method to use and when?

Richard Shores- USEPA Office of Research and Development and Roger Green –

Waste Management

An EPA representative presented on OTM 10 and Cavity Ring Down Methods for Quantification 

of Emissions from Landfills and Other Large Area Sources. Discussion followed.

Only a small group of people have the expertise to do OTM-10 and tracer correlation studies. 

EPA is continuing to refine the methods and make them practical.

In response to a question about the eddy covariance method, the presenter said that method has

longer term development potential. It assumes there is a homogeneous flux, but gives temporal 

changes. Another EPA representative added that other methods such as OTM 10 and the tracer 

method are more developed and tested in applications such as landfills.

The error bars on the abatement efficiency slide (#20) are just measurement error. The methane 

abatement efficiencies do not show variation over time or variation across the landfill. 

The efficiency shown = recovered/recovered + emitted. Abatement efficiency could be different 

whether or not oxidation was considered. One attendee said that when he has studied abatement 

in cases where he could account for oxidation based on data, he saw relatively little difference 

and the difference was within the error of the measurement methods.

The second speaker presented on Landfill Methane Emissions Quantification-OTM 10 and 

Tracer Correlation Approach

From the Summary slide:

• Work has shown that both the OTM-10 and Tracer Correlation can be used to quantify 

emissions from landfills. Both have pros and cons.

• Both techniques use equipment that is commercially available, requiring software and 

expertise to operate properly. 
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• Both techniques can help inform emission estimates and hopefully result in more 

effective control of landfill gas emissions.

• Additional work is needed to define these methods as an alternate test method for area 

sources.

• Additional methods are being investigated

The speaker concludes that none of the methods presented are ready for use in regulations. They 

are costly and produce only short snapshots (e.g., two weeks of data).

EPA is continuing to work on tracer methods. They are closer to being commercially available. 

There are some issues with data quality. For example, methane pooling in stagnant early morning 

conditions, which led to poor tracer correlation. 

The cost for the tracer method is less than OTM-10 in terms of labor. Waste Management used a 

two-person crew on the tracer method, but more than four are needed to set up OTM-10. The 

size and complexity of the landfill layout affects how many days are needed. An EPA 

representative estimates approximately $20-40K per test.

2:30 PM Landfill Gas Treatment for Beneficial Use

Hillary Ward –USEPA Sector Policies and Programs Division and Amy BanisterWaste Management

Presenter provided a brief history of the landfill NSPS treatment requirements and stated that 

treatment would be addressed in the Federal Register notice for the 8-year review of the NSPS.

The second presenter presented Waste Management’s perspective on landfill gas treatment for 

beneficial use. 

She requested that EPA return to the 2002 proposed definition of treatment: filter, de-water, and

compress landfill gas. Waste Management understands that the 2006 proposed numerical 

specifications provide more certainty for EPA, but the specifications may be too prescriptive and 

thus remove the flexibility that landfill owners/operators need for beneficial use projects. 

Beneficial use projects include engines, turbines, and boilers, but now include uses such as highBtu gas injected into pipelines, conversion to compressed natural gas, and potentially conversion 

to diesel fuels. Waste Management would like the treatment option in the rule to be flexible 

enough to accommodate all the potential uses.

Attendees reiterated and expanded on the challenges of prescriptive treatment requirements:

• Treatment varies by end use, so one size does not fit all.

• Treatment is typically in closed loop systems, therefore, does not have emissions.

Combustion end uses of treated gas are already covered by other emission standards such 

as NSPS and NESHAP for engines and turbines; upcoming industrial, commercial, and 

institutional boilers and process heaters NESHAP; and vehicle emission standards. 

Therefore further regulation of post-treatment uses under the landfills NSPS is not 

necessary.
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• The treatment option has built-in incentives for the owner/operator to design and operate 

the system properly even without specific numerical requirements: 

o maximize up-time for the energy project

o avoid damage to and extend the life of the energy recovery equipment

o must meet the end user’s specifications in order to sell the gas

o manufacturer will not warranty the equipment unless the landfill gas meets the 

manufacturer’s specifications.

Attendees stated that many projects are already marginal in terms of cost effectiveness and many 

developers or end users are already willing to switch to natural gas. Thus, any additional costs 

due to meeting treatment could make some projects even less cost effective. One attendee stated 

that many beneficial use projects cannot recover their costs with today’s lower prices of natural 

gas. 

Several attendees from industry also requested that EPA retain what was stated in the 2002 

proposed amendments: once the landfill gas has been treated, then there are no further 

requirements for facilities that buy or use the gas.

Various industry attendees also stated that meeting numerical treatment specifications would be 

an additional cost. If the treatment numerical specifications were not met, then the enclosed 

combustor would have to meet monitoring requirements, which is also a cost. 

3:15 PM Alternate Compliance Pathways: Source Separation and Composting

Kerry Kelly-Waste Management and Frank Franciosi- US Composting Council

The first presenter presented several slides on the percent recovery of organics in 2010 and 

current organic processing technologies. She made the following points, in addition to the 

information on the slides. 

The trend in managing waste is to separate organics from the waste stream, thus keeping 

organics out of the landfill. Waste Management is adjusting to this trend; it currently has 36 

facilities that manage organics. Waste Management sees interest from both the public and private 

sector. 

States are starting to focus on emissions from managing organics such as food waste, specifically 

odors and methane (greenhouse gas) emissions. 

• States may require contained composting, rather than windrows.

• Some States such as Washington and California have developed sophisticated regulations 

for food waste. Regulations may address elements such as siting, air, water, size and 

material being managed, design, operation, and permitting.

Food waste is harder to manage than other waste streams. Operators must manage for odors and 

methane emissions. 

• Odor control becomes more important as composting facilities move closer to 

populations
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• Because of high organic content, methane emissions are high

• Source separating food waste can be challenging.

Aerated, covered composting can reduce emissions; contained anaerobic digesters can reduce 

emissions even more, but their size may limit the volume of waste that can be handled. Digesters 

result in valuable soil amendments and some also recover methane. 

Discussion: 

One attendee stated that in extreme non-attainment areas of California, composting food waste 

can potentially be a significant source of emissions. Facilities are enclosed in buildings and 

emissions are vented to large biofilters. Other attendees indicated that decisions on feasibility of 

composting and other organic waste management options depend on regional and local 

considerations.

The same attendee also stated that landfilling food waste results in lower greenhouse gas 

emissions than composting. However, others indicated that such a statement is too broad. The 

results of such a comparison vary depending on the specific landfill and the type of composting 

operations being compared and are influenced by the design, operation, controls in use, etc. at 

the landfill and the composting operation.

The second presenter presented “Alternate Compliance Pathways: Composting.” He stressed the 

importance of considering composting from a broader perspective. Composting is important 

because it returns carbon and nutrients back to the land thereby improving soils, improving 

agricultural yields, and fostering sustainable land uses and landscapes. 

4:00 PM Closing Remarks

Hillary Ward- USEPA Sector Policies and Programs Division

4:15 PM Adjourn
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Attachment A — Agenda 

Landfill NSPS Technical Meeting Agenda

RTP Meeting Location: C114

Conference Line (919)541-4486

Monday October 22, 2012 

NOTE: All Times are Eastern Standard Time

10:30 AM Opening Remarks

Peter Tsirigotis –USEPA Sector Policies and Programs Division

10:45 AM Early Collection System Installation Incentives: Design and Operations

Angela Marconi- Delaware Solid Waste Authority

11:30 AM Surface Monitoring Requirements 

Renaldo Crooks- California Air Resources Board, Scott Walker- CalRecycle, and 

Pat Sullivan –SCS Engineers

12:15 AM BREAK FOR LUNCH

1:00 PM Updated k values based on using more detailed landfill gas collection and 

header pipe data 

Dr. Morton Barlaz- NC State University 

1:45 PM ORS and Cavity Ring Down – Which method to use and when?

Richard Shores- USEPA Office of Research and Development and Roger Green –

Waste Management

2:30 PM Landfill Gas Treatment for Beneficial Use

Hillary Ward –USEPA Sector Policies and Programs Division and Amy BanisterWaste Management

3:15 PM Alternate Compliance Pathways: Source Separation and Composting 

Frank Franciosi- US Composting Council and Kerry Kelly-Waste Management

4:00 PM Closing Remarks

Hillary Ward- USEPA Sector Policies and Programs Division

4:15 PM Adjourn
10/ϮϮ/2012

Early Collection

Angela Marconi, Delaware Solid Waste Authority

EPA RTP Meeting

October 22, 2012

Early Collection At Present

• NSPS 5/2 year rules

• Initial collection is often from leachate

collection system (LCS)

– Diffi lt/N t Difficult/Not possible t l o comply with O li it 2 limits

– Oxygen and temperature reads from the LCS are

not indicative of conditions within the landfill.

Early Collection At Present

• Operation within the landfill

– Low overall flow can cause operational problems

– Low flow wells can be difficult to operate while

maintaining compliance

– Higher Operating Values (HOV) are difficult to

obtain from state/regional regulating authorities

– Low gas quality can negatively impact beneficial

use projects

Operation Prior to NSPS

• Incentives to operate prior to NSPS

– Beneficial use projects

– Flexibility of operating without NSPS requirements

• Generation drives operation

– Climate conditions affect gas generation and

determine when you start collection

– Design/Operational flexibility required for interim

collection

Attachment B

10
California Air Resources Board 10//2012

California’s Landfill Regulation 

Surface Monitoring Requirements

Landfill NSPS Technical Meeting

October 22, 2012

1

Renaldo Crooks

California Air Resources Board

Presentation Overview

Surface Methane Emission 

Standards

Surface Monitoring Requirements

U S EPA Reference Test Method 21

2

U.S. EPA Reference Test Method 21

Questions

Landfill Methane Regulation

Surface Methane Emission 

Standards

Performance Based Standards

500 ppmv instantaneous surface

3

instantaneous surface

methane emission limit

25 ppmv integrated surface methane 

emission limit

Landfill Methane Regulation

Surface Monitoring Requirements 

Quarterly surface emission 

measurements for active landfills

4

Quarterly surface emission 

measurements reduced to annual (if 

in compliance) for inactive or closed 

landfills, or areas of active landfills 

that are closed or inactive

Landfill Methane Regulation

Surface Monitoring Requirements 

(Cont.)

50,000 square foot grid patterns

5

Probe held within 3” from the ground

25-foot walking pattern spacing 

increased to 100-foot spacing (if in 

compliance)

Landfill Methane Regulation

Surface Monitoring Requirements 

(Cont.)

Surface monitoring terminated:

Average wind speeds >5 mph

6

Average wind speeds >5 mph

Instantaneous wind speed >10 mph

No measurable precipitation 

preceding 72 hours of monitoring

Attachment B

11
California Air Resources Board 10//2012

Landfill Methane Regulation

50,000 Square Foot Grid Walking Pattern

25 feet

200 feet

7

250 feet

Landfill Methane Regulation

Surface Monitoring Requirements 

(Cont.)

Recordkeeping

Records to be kept for 5 years

8

Records to be kept for 5 years

Reporting

Annual Report

Landfill Methane Regulation

Surface Monitoring Requirements 

(Cont.)

U.S. EPA Reference Method 21

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Hydrocarbon Detector Instrument 

Specifications

Renaldo Crooks, Staff Lead

rcrooks@arb.ca.gov

(916) 327-5618

Richard Boyd, Manager

Contacts

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Richard Boyd, Manager

rboyd@arb.ca.gov

(916) 327-8285

Landfill Methane Control Measure Website:

http://www.arb.ca.gov/cc/landfills/landfills.htm

Questions about the Surface 

Monitoring Requirements?

11

Attachment B

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10/ϮϮ/2012

Surface Emissions Monitoring

(SEM) under AB 32 Landfill

Methane Rule (LMR)

Patrick Sullivan, SCS

EPA RTP Meeting

October 22, 2012

Differences between NSPS and LMR

• Integrated SEM in grids; 25 ppmv limit

• 25‐foot (in grids) vs. 30‐meter spacing on

instantaneous SEM

• Monitoring of all cover p , enetrations, each

quarter

• Rainfall and wind speed requirements

• Closed areas vs. closed landfill for annual SEM

• Monitor all disposal areas vs. 2‐/5‐year areas

• No O2 or temp wellhead requirements

Issues and Questions

• Which provision(s) of the LMR is EPA

considering for the NSPS ?  

– Industry can provide data if we are clear on what

is on the table ?

• Are the enhanced SEM elements cost‐effective

monitoring techniques ?  

– Cost‐effectiveness analysis will be critical and

telling; this is an expensive rule.

Issues and Questions (cont.)

• Do the same regulatory conditions exist in the

other 49 states to justify the LMR ?

– CA has unique situation including climate change

statutes statutes and multiple multiple ozone non‐attainment attainment areas

• Any consideration of enhanced SEM from the

LMR must also consider negotiations on other

elements of the rule

– For example, elimination of wellhead standards for

O2 and temp

Issues and Questions (cont.)

• Before decision on inclusion (or not) of LMR

elements, EPA must review data from 1 to 1 1⁄2

years of rule implementation

– LMR is still pretty new;  it is important important to know

how things really played out in the field

Attachment B

13
Modernizing Models and Data on 

Methane Production from U.S. Municipal 

Solid Waste (MSW) Landfills

Xiaoming Wang, Ajay S. Nagpure,

Joseph F. DeCarolis, and Morton A. Barlaz

Department of Civil, Construction, and Environmental Engineering

North Carolina State University

Raleigh, NC

1

 Landfills were estimated to be the third largest 

source of anthropogenic CH4 emissions in the 

U.S. in 2009, accounting for 17% of total CH4

emissions (117.5 Tg CO2 Eq.) (US EPA, 2011).

f f

Introduction

 Prediction o methane generation is critical for 

– regulatory and inventory purposes;

– evaluation of the feasibility of landfill gas (LFG)-

to-energy projects

– allocation of capital investments to required 

equipment

2

Landfill Gas Emissions Model (LandGEM V3.02)

– Qn is the CH4 generation rate (m3/yr) in year n; 

– k is first order waste decay rate (1/yr); 

,

1.0

0

1 0.1 10

i j

n k t i

n

i j

M Q kL e 

 

          

– L0 is the CH4 generation potential (m3/Mg wet waste); 

– Mi is waste mass placement in year i (Mg); 

– tij is age of the jth section of waste mass Mi accepted in 

the ith year (decimal years, e.g., 3.2 years).

3

 EPA inventory defaults

– L0 = 100 m3 CH4/Mg wet waste

– k = 0.04 yr-1

 Obtain an improved data set and use it to 

develop better estimates of k

 Provide estimates of uncertainty. 

e.g., 90% probability of 200 m3/min, but only a 

75% probability of 250 m3/min and a 50%

Objectives

75% probability of 250 m /min and a 50%

probability of 350 m3/min

4

 LandGEM defaults were developed in mid1990s

– predicted methane collection ranged from 38-

492% of actual measured.

 More data and knowledge available for different 

l dfill ti

Rationale

landfill practices:

– waste composition is changing;

– cover practices have changed

– gas collection efficiency varies over time

 Changes in landfill operations suggest that a 

review of LandGEM defaults is appropriate.

5

 11 MSW landfills were visited for site-specific 

information and data, including: 

– Monthly methane collection for 5 to 10 years, except 

one landfill with 3.5-year data

– Mass of biodegradable MSW disposed, as opposed to

Data Collection

Mass of biodegradable MSW disposed, as opposed to

inert waste that would not generate methane (e.g., 

contaminated soil)

– History of LFG collection system installation and 

operation

– History of cover installation

– Other information that would impact LFG generation 

(e.g., leachate recirculation)

6

Attachment B

14
 LandGEM re-formulated on a monthly basis

 A collection efficiency factor, αij, used to convert methane 

generated to methane collected

Estimation of Methane Collection Rates

0 12

12



            

j i j k

j ij i

k L Q Me

– Qj is the monthly CH4 collection rate (m3/month) in month 

j;

– Mi is the waste mass placed in month i (Mg);

– αij is the gas collection efficiency in month j associated 

with mass deposited in month i;

– (j-i)/12 is the age of the ith month of waste mass Mi in 

month j (yr). 7

12 i1

Location of Waste Disposal and Schedule of GCCS 

Installation at Landfill G

8

Years of waste burial

1986-

1995

1996-

1999

2000-

2004 2005 2006 2007 2008 2009 2010

2005 Jan - 90 60 0 0 00000

2006 Sep 90 60 0 0 00000

2006 Oct - 90 75 40 0 00000

2007 June 90 75 40 0 00000

2007 July - 90 90 40 0 0 0 0 0 0

Estimates of αij for Landfill G during methane collection 

(%)

9

 Estimates are uncertain and require judgement, but 

cannot be ignored.

Months of 

methane 

collection

y

2007 Nov 90 90 40 0 00000

2007 Dec - 90 90 75 75 75 0000

2008 June 90 90 75 75 75 0000

2008 July - 90 90 90 90 90 0000

2009 Aug 90 90 90 90 90 0000

2009 Sep - 90 90 90 90 90 20 0 0 0

2010 June 90 90 90 90 90 20 0 0 0

2010 July - 90 90 90 90 90 75 50 0 0

2010 Dec 90 90 90 90 90 75 50 0 0

 Measured gas collection 

data are available from 

2006, so we only need to 

estimate αij from 2006.

E ti ti f d d

Location of Waste Disposal and Schedule of GCCS 

Installation at Landfill P2

10

 Estimation of αij depends 

on the cover type and 

the presence of gas 

wells.

Years of waste burial

2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011

2006

JanDec 75 75 75 0 0 0 0 0 0 0 0 0

2007

JanDec 75 75 75 0 0 0 0 0 0 0 0 0

2008

JanApr 75 75 75 0 0 0 0 0 0 0 0 0

Estimates of αij for Landfill P2 during methane 

collection months (%)

Months of 

methane 

collection

2008

MayDec 75 75 75 60 60 0 0 0 0 0 0 0

2009

JanDec 75 75 75 60 60 0 0 0 0 0 0 0

2010

JanMay 75 75 75 60 60 0 0 0 0 0 0 0

2010

JunDec 75 75 75 75 75 50 50 50 50 0 0 0

2011

JanDec 75 75 75 75 75 50 50 50 50 0 0 0

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Estimates of Model Parameter - L0

Waste category Moisture 

(fraction of total wt.)

Methane yield

(mL CH4/g)

U.S. EPA

(% wet wt.)

11 Statewide

study (% wet wt.)

Textiles 0.10 46.4 4.2 2.8~11.0

Wood 0.10 11.6 7.3 0.3~7.7

Food waste 0.70 300.7 17.7 9.5~19.4

Yard trimmings 0.60 62.6 7.1 1.6~12.2

Miscellaneous 

organics 0.50 125.0 0.2 1.3~5.7

Newspaper 0 06 74 3 0 9 27 56

12

Newspaper 0.06 74.3 0.9 2.7~5.6

Office paper 0.06 217.3 4.3 2.0~6.4

Mixed paper 0.06 145.8 2.9 3.9~8.8

Glossy paper 0.06 84.4 0.9 1.0~3.6

OCC/Kraft bags 0.05 152.3 5.7 4.0~17.2

Composite/

miscellaneous 0.06 132.1 9.3 7.4~15.0

Calculated L0 (mL CH4/g = m3 CH4/Mg) 54.3 58.2~70.5

 As an intrinsic property of waste, L0 should range between 

55 and 70 m3 CH4/Mg wet waste. Using optimistic 

assumptions, we obtain an L0 of 80 m3 CH4/Mg wet waste. 

Attachment B

15
 EPA default approach: L0 = 100 m3 CH4/Mg, k = 0.04 yr-1.

 L0 – varied approach:

– Let L0 = 55, 70, 85, and 100 m3 CH4/Mg, respectively;

– Nonlinear regression for optimal k by minimizing the 

sum of squared errors (SSE).

Estimates of Model Parameter - k

• j ranges over the total number of months during which the field 

CH4 collection data are available for a particular landfill (i.e, 

months l through m); 

• Qcalc,j is the calculated monthly methane collection rate, 

m3/month; and Qmeas,j is the measured monthly methane 

collection rate, m3/month. 13

 2

, ,



  

m

calc j meas j

j l

SSE Q Q

Estimated and Observed Methane Collection at Landfill G

4.0E+05

6.0E+05

8.0E+05

1.0E+06

1.2E+06

1.4E+06

1.6E+06

ne Collection (m3 / month)

AP-42 ( Lo= 100 , k= 0.04) Lo = 55, k =0.12

Lo = 70, k =0.11 Lo = 85, k =0.11

Lo = 100, k =0.1 Observed

14

 Initially, the model under predicts collected gas. As a result, higher L0

scenarios give better fits. Note that higher k is required and LandGEM

defaults are quite poor. 

 If L0 is allowed to vary with k simultaneously, L0 will become more like a 

fitting parameter rather than representing its physical meaning of 

methane generation potential. 

0.0E+00

2.0E+05

Methan

Collection Month

80

100

120

140

160

180

200

(Fraction of AP-42 )

AP-42 (Lo= 100,k=0.04) Lo= 55 Lo= 70 Lo=85 Lo= 100

Sum of Squares Error (SSE) Observed at Each Landfill under 

Different LandGEM Parameterizations

15

0

20

40

60

S G H T C1 P1 M Q C2 P2 N

SSE 

Landfill ID

 The parameterizations with low L0 values result in higher errors, while 

those with higher L0 values result in lower errors. 

 The SSE for Landfill T at L0 = 55 m3/Mg is a factor of 443 higher 

than the AP-42 value and not shown.

Sum of Squares Error (SSE) Observed at Each Landfill under 

Different LandGEM Parameterizations

(with 6-month lag time) 

80

100

120

140

160

180

200

raction of AP- 42)

AP-42 (Lo= 100,k=0.04) Lo= 55 Lo= 70 Lo=85 Lo= 100

16

 While the lag time effectively increases the estimate of methane 

generation, the small relative magnitude of the 6-month lag time 

compared to the multi-year collection period for each landfill results in a 

negligible improvement in fit between calculated and observed data.

0

20

40

60

80

S G H T C1 P1 M Q C2 P2 N

SSE (Fr

Landfill ID

100

125

150

175

200

ve CH4 Collection 

of Observed)

EPA default

Lo= 55, optimal 

k varied

Lo= 70, optimal 

k varied

Lo= 85, optimal 

Cumulative Methane Collection at Each Landfill 

(assuming 100% collection)

0

25

50

75

S G H T C1 P1 M Q C2 P2 N

Cumulativ

(% o

Landfill ID

k varied

Lo= 100, optimal 

k varied

Observed

17

 When 100% collection efficiency is assumed, the LandGEM calculation 

with the EPA defaults overestimates collectable methane for 5 landfills, 

underestimates for 5 landfills, and matches closely in one case. 

Cumulative Methane Collection at Each Landfill 

(site-specific collection αij)

75

100

125

150

e CH4 Collection 

f Observed)

EPA default

Lo= 55, optimal 

k varied

Lo= 70, optimal 

k varied

Lo=85, optimal k 

varied

18

 When collection efficiency is taken into account, the 

LandGEM calculations consistently underestimate 

cumulative methane collection. 

0

25

50

S G H T C1 P1 M Q C2 P2 N

Cumulativ

(% of

Landfill ID

varied

Lo= 100, optimal 

k varied

Observed

Attachment B

16
0.08

0.10

0.12

0.14

0.16

0.18

k (1/yr)

0.08

0.10

0.12

0.14

0.16

0.18

k (1/yr)

Optimal k Values at L0 = 100 m3 Mg-1 versus 

Temperature and Precipitation for Studied Landfills

19

0.00

0.02

0.04

0.06

0.08

6 8 10 12 14 16

k

Average Annual Temperature (°C)

0.00

0.02

0.04

0.06

0.08

80 90 100 110 120 130

k

Average Annual Precipitation (cm)

 The lack of correlation may be due to the narrow ranges of 

temperature and precipiation.

CH4 generation potential (L0) and corresponding 

optimized first order waste decay rate (k) for landfills 

Landfill Leachate 

recirculation L0 = 55 L0 = 70 L0 = 85 L0 = 100

S Y 0.17 0.17 0.16 0.12

G Y 0.12 0.11 0.11 0.1

H Y 0.15 0.15 0.15 0.15

T Y 0 12 0 12 0 06 0 04

Landfills S, H, C1, 

M, Q, C2 have 

highest k; 3

20

T Y 0.12 0.12 0.06 0.04

C1 N 0.17 0.17 0.17 0.17

P1 N 0.09 0.06 0.04 0.03

M Y 0.17 0.17 0.17 0.17

Q N 0.14 0.14 0.14 0.13

C2 N 0.15 0.15 0.15 0.15

P2 N 0.16 0.15 0.09 0.07

N N 0.16 0.15 0.11 0.07

highest k; 3

recirculate and 3 do 

not

Landfill T has a low 

k and it recirculates. 

4.0E+06

6.0E+06

Collection (m3/month)

S G H T

C1 P1 M Q

C2 P2 N

Predicted vs. Observed Methane Collection at Each Landfill

4.0E+06

6.0E+06

Collection (m3/month)

S G H T

C1 P1 M Q

C2 P2 N

21

0.0E+00

2.0E+06

0.0E+00 2.0E+06 4.0E+06 6.0E+06

Predicted CH4 C

Observed CH4 Collection (m3/month)

0.0E+00

2.0E+06

0.0E+00 2.0E+06 4.0E+06 6.0E+06

Predicted CH4 C

Observed CH4 Collection (m3/month)

 The closer the data to the dashed line, the better the 

predictions fit the field measurements, suggesting default k 

needs to be updated.

Lo=100, 

k=0.04

Lo=100, 

greater k

 Based on 11 landfills, the results suggest that EPA 

defaults need to be updated to improve accuracy in 

estimation of methane production.

 The plausible range of L0 (55-80 m3 CH4/Mg), derived 

Preliminary Conclusions

p g 0 ( 4 g),

from waste composition data, produce a poor match to 

the measured data. In contrast, higher L0 values produce 

a better fit to the data, suggesting these L0 values might 

‘absorb’ effects of some unmodelled factors, such as lag 

time or the role of precipitation and temperature in waste 

decomposition.

22

 Characterize uncertainty in parameter estimates and 

model predictions.

 Explore alternative formulations to LandGEM that could 

provide an improved representation of methane 

generation.

 Exercise both the current formulation of LandGEM with

Future Work

Exercise both the current formulation of LandGEM with

improved defaults and an improved model formulation to 

estimate a methane emissions inventory for U.S. landfills.

23

 Environmental Research and Education 

Foundation (EREF)

 Republic Services

 Veolia Environment Services

Acknowledgements

 Waste Management

 Waste Connections

 Site personnel and supporting engineers

24

Attachment B

17
Questions?

25

Attachment B

18
10//2012

OTM 10 and Cavity Ring Down Methods for Quantification of 

Emissions from Landfills and Other Large Area Sources

Landfill NSPS Technical Meeting

October 22, 2012, Research Triangle Park, NC

R.C. Shores, S. Thorneloe, E.D.Thoma - EPA, ORD, 

National Risk Management Research Lab 

R. B. Green, G. R. Hater - Waste Management Inc. 

Office of Research and Development

National Risk Management Research Laboratory, Air Pollution Prevention and Control Division

Photo image area measures 2” H x 6.93” W and can be masked by a 

collage strip of one, two or three images.

The photo image area is located 3.19” from left and 3.81” from top of page. 

Each image used in collage should be reduced or cropped to a maximum of 

2” high, stroked with a 1.5 pt white frame and positioned edge-to-edge with 

accompanying images.

NRMRL Fugitive and Area Source Group

Source and Fenceline Measurements

Methods and Technology Development

Fugitive and area sources 

improved emissions knowledge is needed

A i lt l ti i d ti l f iti

1

Agricultural operations, industrial fugitives, coal mining, waste water, oil and gas 

production, and many more

Landfill emissions are particularly 

difficult to quantify

• spatially variable

• temporally variable

• large spatial extent

Presentation Overview

• Measurement methods

–OTM-10

–Tracer Correlation

–Method comparisons

–N th d ew methods, i.e, eddy covariance

• Method applications

• On-going collaborations

2

• OTM-10 can be useful for the evaluation of surface emissions between different 

cells, types of covers and landfill operations

• Evaluation of a large facility requires multiple OTM-10 setups depending upon 

the complexity of the site, ultimately measuring a percentage of the entire facility

• Recognize OTM-10 challenges for landfill applications and working to provide 

future guidance for OTM-10 application to landfills with challenges such as

OTM-10 Overview

3

– Influence of by near-by sources, barometric pressure, and moisture content 

in surface cover

– Constantly changing topography and difficulty in measuring side slopes

– Spatial and temporal variability

– Difficulty in determining footprint

– Reliant upon wind direction and speed

EPA OTM 10

vertical radial plume mapping

4

Optical remote sensing for emission characterization from non-point sources 

EPA OTM 10,(2006), http://www.epa.gov/ttn/emc/prelim/otm10.pdf

Typical OTM 10 Application 

Measuring CH4 emissions from part of landfill

5

Open-Path Tunable Diode Laser Absorption Spectroscopy for Acquisition of Fugitive Emission Flux Data, 

E. Thoma, et al., Jor. of the Air and Waste Manage Assoc 55, 658-668 (2005).

Evaluation of Fugitive Emissions Using Ground-Based Optical Remote Sensing, U.S. EPA Report 

EPA/600/R-07/032 (2007), at Web Site: http://www.epa.gov/nrmrl/pubs/600r07032/600r07032.pdf

Attachment B

19
10/2012

OTM10 Example - Landfill Bioreactor Cell 

• Experimental Municipal Bioreactor 

(not typical, not a WM site)

• Air and leachate injection

• Open wells on side slope

6 TDL Source

Tracer correlation overview

• Provides a whole facility measurement but difficult 

to relate to cell specific information

• The approach using simple (but powerful) 

spectroscopic instruments and acetylene as a 

tracer is useful

• Release tracer gas from strategic locations within 

the facility 

• Use mobile monitor to map target source and tracer

large area 

source 

Wind

source plume

tracer plume

tracer release point(s)

7

• Use mobile monitor to map target source and tracer

plumes 

• Calculate dilution ratio based on known tracer rate

• Measurement technology is commercially available

• Less resource intensive than OTM-10

• Must have access around landfill perimeter at the 

appropriate distance 

• Could be combined with OTM-10 to partition 

specific emission sources within landfill facility 

target target target, bckgnd

tracer tracer tracer, bckgnd

Q CC

Q CC

  

Tracer and Methane plumes

Tracer correlation method

8

3 x 25 lpm C2H2

12

Mobile and stationary tracer correlation

y = 0.177x + 0.048

R2

 = 0.881

0.0

0.2

0.4

0.6

0.8

1.0

Methane -1.9 (ppmv)

Mobile

9

0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 Acetylene (ppbv)

y = 0.168x + 0.072

R2

 = 0.919

0.0

0.2

0.4

0.6

0.8

0.0 1.0 2.0 3.0 4.0 5.0 Acetylene (ppbv)

Methane -1.9 (ppmv)

Draft

Stationary

26

Tracer Correlation and QA Development

10

Draft

EPA EP-C-07-15, WA 2-10 (2009) 

8:15 a.m. 10:30 a.m.

Methane pooling in stagnant 

early morning conditions 

(poor tracer correlation)

Met sets up in mid-morning 

(good tracer correlation)

Four GMAP REQ systems in the field

EPA R5 EPA ORD

11

Waste Management EPA NEIC

Attachment B

20
10//2012

Auto-north met 

station 

Quad

Sampling Port

In the truck:

High-precision CH4 Instrument (critical component)

Batteries, control system, IR camera, rangefinder

GMAP REQ measurement equipment

3D sonic 

anemometer

1.4 litter canister 

placement

High-res GPS 

12

Method and engineering package development

(to be submitted to EPA OAQPS for posting consideration as preliminary method)

Analysis Software Acquisition Software

13

Engineering Design

Technique comparison study

methane release (EREF*-funded study)

Landfills Methane Fugitive emissions, field comparison of methods. A Babilotte, et al., 12th 

International Waste Management and Landfill Symposium, October 5-9, 2009. Sardinia, Italy

Tracer 

Correlation DIAL OTM 10 OTM 10 OTM 10

A. Babilotte, Veolia

14

*EREF- Environmental Research and Education Foundation

Remote Emission Measurements

OTM 10, bLS, DIAL, Tracer Correlation

 0.2 km

Source

OTM 10

bLS

15  1 km

DIAL

Tracer Correlation ( 1 km)

Real-world Field Work by Industry 

and EPA Collaborations

Dates Facility Location

2009

May 18 – 21, 2009 Twin Bridges Danville, IN

October 5 – 7, 2009 Redwood Novato, CA

October 18 – 22, 2009 Altamont Livermore, CA

2010 July 21 – 23, 2010 Twin Bridges Danville, IN

July 30, 2010 Outer Loop Louisville, KY

August 17 – 18, 2010 Twin Bridges Danville, IN

August 24 – 26, 2010 Stony Hollow Dayton, OH

Dates Facility Location

2011

June 1 – 3, 2011 Turkey Run Lone Oak, GA

June 14 – 16, 2011 Turkey Run Lone Oak, GA

August 9 – 10, 2011 Centerpoint Centerpoint, IN

August 24 – 25, 2011 Twin Bridges Danville, IN

August 31, 2011 South Wells Liberty Center, IN

September 7 – 8, 2011 Centerpoint Centerpoint, IN

September 13 – 14, 2011 Twin Bridges Danville, IN

September 21 – 22, 2011 South Wells Liberty Center, IN

October 11 – 12 2011 Centerpoint Centerpoint IN

16

August 31 – September 2, 2010 Suburban Glenford, OH

September 8 & 10, 2010 Outer Loop Louisville, KY

September 14 – 15, 2010 Twin Bridges Danville, OH

September 16 – 17, 2010 South Wells Liberty Center, IN

September 21 – 22, 2010 Stony Hollow Dayton, OH

September 23, 2010 Springfield Springfield, OH

October 19 – 21, 2010 Springfield Springfield, OH

October 26 – 27, 2010 Stony Hollow Dayton, OH

November 2, 2010 Seneca East Republic, OH

November 4, 2010 South Wells Liberty Center, IN

November 9 – 10, 2010 Centerpoint Centerpoint, IN

November 11 – 12, 2010 Twin Bridges Danville, IN

November 16 – 17, 2010 Suburban Glenford, OH

December 1 – 2, 2010 Outer Loop Louisville, KY

October 11 12, 2011 Centerpoint Centerpoint, IN

October 25, 2011 South Wells Liberty Center, IN

November 2 & 4, 2011 Twin Bridges Danville, IN

November 16 – 18, 2011 Turkey Run Lone Oak, GA

November 30, 2011 Centerpoint Centerpoint, IN

December 1, 2011 Twin Bridges Danville, IN

December 6, 2011 South Wells Liberty Center, IN

December 14 & 16, 2011 Valencia Los Chavez, NM

2012 (ongoing)

April 2012 Turkey Run Lone Oak, GA

May 2012 Twin Bridges Danville, IN

June 2012 Turkey Run Lone Oak, GA

June 2012 Plumb Thicket

15000

20000

25000

Estimate (g/min)

Tracer Correlation Emission Estimates by Site 

(DRAFT 040711)

Working Landfills

17

0

5000

10000

0123456789

CH4 Emisson E

Landfill Sites

bars = +/- 1 stdev

revison 1 uncleared draft data, subject to change 

Closed Landfills

Attachment B

21
10//2012

CH4 Emission Calculations

Methane Abatement Efficiency (%) = 

CH4 recovered / ( CH4 recovered + CH4 emitted) x 100

Collection Efficiency (%) = 

(CH4 recovered /CH4 produced) x 100

18

Control Efficiency (%) = 

(CH4 recovered + CH4 oxidized / CH4 produced) x 100

where: CH4 produced = CH4 recovered + CH4 emitted + CH4 oxidized

CH4 recovered = total flow rate of header pipe gas (adjusted for air intrusion) 

Waste Management CH4 Oxidation, Collection 

and Control Efficiency at Three California 

Landfills using OTM-10 and Stable Isotopes

Methane 

Oxidation

(%)

Collection 

Efficiency

(%)

Control Efficiency

(%)

Lancaster 9/07 0* 92 92

Lancaster 1/08 0* 81 81

19

TriCities 2/08 24 86 88

TriCities 6/08 29 88 90

Kirby Canyon 2/08 21 84 87

Kirby Canyon 6/08 62 72 84

*Insufficient methane to perform isotope analysis for oxidation

Methane Abatement Efficiency

20

Current AP42 values are 50 to 95% with average of 75%.

Above data range from 40 to 90% with an average of 77%. 

U.S. EPA, Quantifying Methane Abatement Efficiency at Three Municipal Solid Waste Landfills, 

EPA/600/R-12-003, Jan 2012

• Long term assessment tool of the facility

• Method used for homogeneous flux 

measurements by NOAA and USDA

• Represents a percentage of the facility

• Being investigated

Eddy Covariance overview

21

Methane Flux

22

Liukang Xu, Jim Amen, Xiaomao Lin-LI-COR Biosciences

Methane Flux

23

Liukang Xu, Jim Amen, Xiaomao Lin-LI-COR Biosciences

Attachment B

22
10//2012

Discontinuity between measurements 

and LandGEM emission estimates 

• Recognize that there can be several orders of magnitude difference 

between measured and modeled emissions

• Experts have suggested that best way to determine landfill gas 

quantity is (1) to install well field, (2) allow it to equilibrate for ~ one 

year, and (3) then measure the flow rate

• Difficulties in defining an accurate Lo to waste composition which 

changes over time and will be variable across the landfills

• Hopefully more recent data can help reconcile current uncertainties 

and improve emission inventories

• Will also help improve projections for future energy projects by 

reducing investment risk 

24

• Work has shown that both the OTM-10 and Tracer Correlation can be 

used to quantify emissions from landfills. Both have pros and cons.

• Both techniques use equipment that is commercially available, requiring 

software and expertise and to operate properly. 

• Both techniques can help inform emission estimates and hopefully result

Summary

Both techniques can help inform emission estimates and hopefully result

in more effective control of landfill gas emissions

• Recognize that additional work is needed to define these methods as an 

alternate test method for area sources 

• Additional methods are being investigated

• EPA is appreciative to all CRADA partners to help leverage resources 

and expertise in developing improved measurement methods

25

Collaborator and contractor acknowledgments

• Gary Hater, Roger Green - Waste Management (EPA CRADA #372-A-08)

• Nathan Swan, Cygus Environmental

• Eben Thoma, Susan Thorneloe, Bill Squier, Gayle Hagler – EPA/ORD/NRMRL/APPCD

• Thabet Tolaymat, Fran Kremer - EPA ORD NRMRL LRPCD

• Robin Segall, Jason DeWees - EPA OAQPS 

• Jeff Chanton, Tarek Abichou - Florida State University

26

• Doug Goldsmith, Alternative Natural Tefchnologia

• Will Stevens – Kentucky Christian University

• Chris Rella, Eric Crosson – Picarro Inc.

• Tracey Footer - Eastern Research Group (EP-C-07-015)

• Mark Modrak, Shahrooz Amin - Arcadis (EP-C-09-027)

Thanks 

Attachment B

23
10//2012

Landfill Methane Emissions Quantification‐

OTM 10 and Tracer Correlation Approach

Roger Green

Waste Management

Landfill NSPS Technical Meeting

October 22, 2012

Presentation Overview

•EREF Method Comparison Study (2008)

•OTM‐10 Study at 20 US landfills

•Tracer correlation results from new and closed landfills without gas

collection

2008 EREF Method Comparison Study

Participants

Participant Method Country

WM

ARCADISUS

Vertical Radial Plume

Mapping (VRPM) USA

Finnish Meteorological

Institute

Micrometeorological

Eddy‐Covariance Finland

WM/Landfill+ Inc./Florida

State University Static Flux Chamber USA

National Physical

Laboratory

Differential

Absorption LiDAR

(DiAL)

UK

FLUXSENSE AB Mobile Tracer Plume

FTIR spectroscopy Sweden

2008 EREF Emission Method Comparison Study

Landfills

Whole Landfill Emission Results

OTM‐10

Metro

• 4.5 days of data collection

• 3 locations

• ~15% of landfill covered

Emerald Park

• 2 days of data collection

• 2 locations

• ~10% of landfill surface covered

Whole Landfill Emission Results

Mobile Tracer Correlation

Metro

• 4 days of data collection

• 1 area

• Active area ~30% of landfill area

Emerald Park

• 2 days of data collection

• 1 area

• Active area ~ 45% of landfill area

Attachment B

24
10//2012

Whole Landfill Emission Method Comparison

Metro

Global Emission

(kgCH4/h)

Associated

coeffcient of variation

Landfill area

analyzed

Time of data collection during campaign (days)

VRPM 1325 28%<cv<84% ~15% 4.5

Chamber Chamber 295 175%<cv<400% 175%<cv<400% ~3% 4

MicroMet 1005 >30% ~30% 6

Tracer 916 5%<cv<8% Whole landfill 4

DiAL 659 28%<cv<43% Whole landfill 3

Whole Landfill Emission Method Comparison

Emerald Park

Global Emission

(kgCH4/h)

Associated

coeffcient of

variation

% landfill area

analyzed

Time of data collection during

campaign (days)

VRPM 1244 14%<cv<30% ~10% 2

Chamber 868 122%<cv<260% 0 8%. 2

MicroMet 1146 >30% ~11% 3.5

Tracer 789 11%<cv<14% Whole landfill 2

DiAL 314 20%<cv<48% Whole landfill 2.5

OTM‐10 Study Locations and Climate

Goldsmith et al., (2012) "Methane emissionsfrom 20 landfills acrossthe United States using vertical radial plume mapping",

J.Air & Waste Manage. Assoc. 62:2, 183‐197.

Determining the Area Contributing to Flux (ACF) for

OTM‐10

Multiple Linear Regression Model (MLRM)

• Based on fit of controlled acetylene and methane release data. Includes collection

efficiency at the VRPM plane, the wind adjusted distance of the release from the

plane and wind speed.

Thoma, E., R. Green, G. Hater, C. Goldsmith, N. Swan, M. Chase, and R. Hashmonay. 2010. Development of EPA

OTM‐10 for l dfill li ti landfill applications. J. E i nv ron. Eng. 136 769 : –776.

Pasquil Stability Class‐Based Model (PSCM)

• Virtual VRPM computer model based on ISC3 and Pasquil stability classes.

Abichou, T., J. Clark, S. Tan, J. Chanton, G. Hater, R. Green, D. Goldsmith, M. Barlaz, and N. Swan. 2010.

Uncertainties associated with the use of OTM‐10 to estimate surface emissions in landfill applications. J.

Air Waste Manage. Assoc. 60:460–470.

Methane Emission Rate by Cover Type

20 Landfill OTM‐10 Study

‐2 d‐1

)

150

200

250

n=5 n=27 n=19 n=2

Daily Intermediate Final (soil) Final (synthetic)

Methane (g m‐

0

50

100

150

Intermediate Cover Emission by Climate

20 Landfill OTM‐10 Study

m‐2 d

‐1

)

100

120

140

160

Methane (g m

0

20

40

60

80

Semiarid Mediterranean Humid

Continental

Cool

Summer

Humid

Continental

Warm

Summer

Humid

Subtropical

Attachment B

25
10//2012

Tracer Correlation Measurements Using Cavity Ring

Down Spectroscopy

CH4 

production 

rate

Collected 

LFG

time

Uncollected

LFG Uncollected

LFG

Landfill Characteristics for New Landfills

without LFGCS

tons

100000

200000

300000

400000

tons 100000

200000

300000

400000

SE SW

Waste In Place (tons) 598,732 677,545

Area (m2) 108,863 68,798

k (yr‐1) 0.057 0.02

DOC (tons C/tons waste) 0.31 0.31

1990 1995 2000 2005 2010

0

100000

1990 1995 2000 2005 2010

0

100000

Measured vs. Modeled Emission Rates for New

Landfills without LFGCS

e (g CH4/m2/d)

15

20

25

SE SW

Emission Rate

0

5

10

CRDS

EPA MRR

Landfill Characteristics for Closed Landfills without

LFGCS

Landfill Area     

(m2)

Waste in Place

(tons)

k   

(yr‐1)

DOC  

(tons C/ ton

waste)

Center Point 198,298 1,7 , 29820 0.038 0.310

Seneca East 178,064 1,578,584 0.038 0.310

South Wells 202,345 1,398,320 0.038 0.310

Springfield 226,626 1,779,243 0.038 0.310

Attachment B

26
10//2012

Waste placement for model

1970 1980 1990 2000 2010

0

100000

200000

Center Point

1970 1980 1990 2000 2010

0

100000

200000

ns

Seneca East

1970 1980 1990 2000 2010

1970 1980 1990 2000 2010

to

0

100000

200000

1970 1980 1990 2000 2010

0

100000

200000

South Wells

Springfield

Measured vs. Modeled Emission Rates

Closed Landfills without LFG Collection

CH4/m2/d)

15

20

25

CRDS

EPA MRR

SWICS

Center Point Seneca East South Wells Springfield

Emission Rate (g C

0

5

10

15

Summary

No method is ready for routine emission measurement for the purposes of permitting

or regulatory compliance.  Significant method improvements, data quality indicators

and standard procedures for use at landfills are required.

Both OTM‐10 and the Tracer Correlation  Approach (TCA) produce short term pictures

of f ilit ac y emi i ss ons.  Additi l Additional research is requi d re to und td ers and t l emporal and

seasonal variation.

OTM‐10 is difficult to set‐up and use due to complex topography and weather

conditions strongly influence ability to obtain usable readings.  

Summary

OTM‐10 can be a useful research tool for estimating emissions from well defined

sections of the landfill with proper setup and analysis.  

OTM‐10 is unlikely to cover more than 25% of the surface at large modern landfills

owing to costs, time constraints and topography.   The uncertainty introduced by

extrapolation of emission factors makes it not the best tool for whole landfill

estimates.

The TCA appears to a better method of determining whole landfill emissions

because it integrates emissions from the entire facility.  Data quality indicators and

best practices still need to be established for landfill application.

Current Activity

Continuing TCA method development with EPA with the objective of producing an

OTM for landfill use.

Working to better understand the magnitude and causes of temporal variation in

emissions from landfills.  This is necessary to properly apply results generated from

‘snap‐shot’ research methods.

EREF Industry Air Study

–Focused on emissions at landfills that have yet to install gas collection systems,

especially new landfills.  

–Participants include Republic, Veolia, Waste Connections, Waste Management and EPA.

–Simultaneous use of tracer correlation w/CRDS and VRPM in an attempt to quantify

whole landfill and active area emissions.

Acknowledgements

• Gary Hater, Waste Management

• Richard Shores, Eben Thoma ‐ USEPA ORD

• Jason DeWees ‐ EPA OAQPS

• Thabet Tolaymat, Fran Kremer ‐ USEPA ORD

• Jeff Chanton, Tarek Abichou ‐ Florida State University

• Doug Goldsmith Goldsmith ‐ Alternative Alternative Natural Natural Technologies Technologies

• Nathan Swan ‐ Cygnus Environmental Group

• Tom Pike ‐ Pike Contracting

• Environmental Research and Education Foundation

• Republic Industries

• Veolia Environmental Services

• Waste Connections

Attachment B

27
10/ϮϮ/2012

Landfill Gas Treatment

Landfill NSPS Technical Meeting 

October 22, 2012

Background - Landfills

► NSPS for landfills was finalized in 1996

► Controls based on emissions of nonmethane organic compounds (NMOC)

► 3 options under the rule

► Open flare

► Enclosed combustor

► Treatment for beneficial use Treatment for beneficial use

► Amendments proposed in 2002 included 

a definition for treatment system

► Would qualify for treatment option 

under 60.752(b)(2)(iii)(c)

► Proposed definition: “system that filters, 

dewaters, and compresses landfill gas”

2

Comments Received After Proposal

► More direction about level to 

which gas should be filtered, 

dewatered and compressed

► Lack of clarity would result in 

inconsistent case-by-case 

determinations

► Gas should be treated to meet Gas should be treated to meet

end-use combustion 

manufacturer requirements

► Develop specific filtration, 

moisture, and compression 

requirements

3

Actions After Proposal

► Agreed with commenters about the need for specificity in the 

treatment definition

► Contacted manufacturers of combustion devices used for energy 

recovery from landfill gas

► Obtained written specifications and recommendations for fuel 

quality

► R i d f t ’ ifi ti f t bl l l f Reviewed manufacturer’s specifications for acceptable levels of

moisture and particulates

4

Actions After Proposal 

► Different manufacturer’s have different specifications

► Amendments proposed in 2006 did not refer directly to 

manufacturer's requirements

► Developed specific filtration and de-watering targets based on 

those requirements

► “A system that has an absolute filtration rating of 10 microns or less, 

lowers water dew point of landfill gas by at least 20 degrees 

F h h it ith d t i Fahrenheit with a dewatering process, and compresses th l dfill the landfill

gas.”

► Selected levels of filtration and de-watering were consistent with 

most manufacturer’s specifications for landfill gas burned in 

energy recovery devices

► Protective of combustion equipment and promoted proper 

destruction of NMOC

► Treatment systems installed prior to the proposal would be given 

1 year to comply with the new treatment requirements

5

Filtration

► Filtration systems: Continuous monitoring (24 hour average) of 

pressure drop across the filter. 

► Pressure drop maintained above minimum pressure drop established 

engineering analysis or manufacturer’s specifications. 

► Option also provided to monitor other parameter’s indication proper 

performance of the filtration system

► Rationale: Pressure drop was a good indicator proper filter Rationale: Pressure drop was a good indicator proper filter

operation. Noticeable reduction in pressure drop across filter 

would indicate a breach of the filter material

6

Attachment B

28
10/ϮϮ/2012

De-watering

► Continuous monitoring of temperature reduction for chiller-based 

dewatering systems

► Continuous measurement of gas required at treatment system inlet 

and chiller outlet unless able to prove that monitoring at one location 

is sufficient

► Continuous monitoring of dew point reduction for non-chiller 

based systems based systems

► Dew point monitoring also required at inlet and outlet unless able to 

prove that monitoring at a single point is sufficient

► Allowed for approval of other parameters indicating proper 

performance of the dewatering system

7

Continuous Monitoring Rationale

► Monitoring needed to ensure continuous compliance

► Continuous monitoring systems are available for the treatment 

operating parameters selected

► Data collection required at 15 minute intervals: consistent with 

requirements for flare pilot flame monitoring and enclosed 

combustor temperature monitoring for landfills using the other 

NSPS control options NSPS control options

► 24-hour block average requirement is sufficient to indicate any 

significant change in operation of the treatment system and is 

less burdensome than more frequent averaging

8

Comments Received After Proposal

► Difficulty meeting treatment requirements in cold climates 

because gas can be cooled from wellhead to about 40°F simply 

by ambient temperature and further lowering of temperature is not 

feasible

► Difficulty verifying inlet and outlet temperatures because they vary 

depending on pressure in the system

► Accounting for these conditions could require multiple points of Accounting for these conditions could require multiple points of

measure plus use of an algorithm to determine the reduction

► Standard does not take into account water removal that may be 

occurring in other parts of the system (e.g. header)

► Level of treatment depends on type and design of specific 

combustion equipment used

► Favored case-by-case determinations

9

Attachment B

29
10/ϮϮ/2012

LFG Treatment

Amy Banister, Waste Management

EPA RTP Meeting

October 22, 2012

LFG Treatment • Rule should promote beneficial use (energy recovery,

high BTU gas, renewable fuels, etc.)

• Inherent incentive to properly operate treatment

system already

• Treatment needs vary based on end‐use

• Closed loop ys stems

• Prescriptive MRR standards proposed in 2006 are a barrier to beneficial use projects

• Other federal standards (NSPS, MACT) control

stationary combustion emissions (Engines, Turbines,

Boilers)

• Drop‐in pipeline, vehicle fuel and tailpipe standards

also control emissions

LFG Treatment

• Remove barriers to promote beneficial use

projects   

• Exempt beneficial use projects full stop

• Use 2002 proposed “treated landfill gas” and

“t t t rea ment syst ” em d fi iti definitions

• Rely on other existing federal rules/standards

for emission control

• Preserve existing site‐specific treatment

determinations

Attachment B

30
10//2012

Fast Facts & Figures – Total U.S.

249 million tons of MSW Generated in 2010

• 85 million tons recycled or composted

• 164 million tons disposed

Recovery of Organics

57% of yard waste recovered

2 8% f f d t d

20.2%

65.7% 14.1% Food 

Waste

Yard and Wood 

Trimmings

Garbage, 

Other 

Recyclables

Landfill Waste Breakdown

2.8% of food waste recovered

174 million tons of MSW is Disposed

• 14 million tons yardwaste (13.7%)

• 35 million tons of food scraps (14%)

*U.S. Environmental Protection Agency: Total MSW

Generation, 2009: 243 Million Tons (before recycling)

Waste=Energy

Food waste

diversion helps

optimize the

value of the

waste stream.

Processing:  Organic Processing Technologies

Technology

d

Open Windrow

Composting

Lower costs‐ Simple system,

easy to operate

Wet or Dry Anaerobic

Digestion

Can be combined with

agricultural or POTW digesters

Aerated Covered

Composting

Smaller footprint & state‐of‐the‐

art system Provides biofiltration Advantages

Challenges

Next Steps

easy to operate

Some risk for odor generation

High VOC emissions‐not suitable

for non‐attainment zones.  

Requires clean FW and YW

streams

Appropriate for dry rural areas

agricultural or POTW digesters.

Generates energy.

Expensive and quantities

processed are limited. Requires

homogenousfeedstock.

Commercial testing in North

America in progress with

several facilities coming on line

this year.  

art system. Provides biofiltration

of process air, Reduce VOC

emissions by 90%

Requires clean food waste and

yard waste streams

Best for large volume urban

areas with air quality concerns

Increased: acreag

distanc

Composting Technologies

ASP‐Natural Cover

Harvest Power

In‐Vessel (Tunnel)

In‐Vessel (Drum)

trol, capital 

onmental perf.

ge, processing time, 

ce to neighbors

Static Pile

ASP‐Synthetic Cover

ECS/Gore Tech.

Traditional Windrow Windrow Turning

ASP‐Natural Cover

Eng. Compost Systems

Increased: process cont

costs, enviro

-------------------------------------------- exhaust air to the environment

exhaust air treatment

3

Food and 

Organics Scraps

Organics Recycling Today & Tomorrow:

Energy is 

Created

Composting, Renewable Energy & Biofuels

Grow 

More Food

Soil 

Amendments

Collection

Processing Fuel is 

Created

Powered by 

Recycled Organics

Attachment B

31
10//2012

Alternate Compliance Pathways: 

Composting

Frank Franciosi-President

“Organics Recovery and Conversion Through Composting”

Mission Statement

The US Composting Council (USCC) advances composting and 

promotes compost use to enhance soils and provide economic

and environmental benefits for our members and society.

Vision Statement

We believe that the recycling of organic materials is central to 

achieving healthy soils, clean water and a sustainable society.

The economic & environmental impact of diverting 

organic residuals destined for Landfills speaks for 

itself----

---Wasted Resource

Far more important are the economic, 

environmental & life style benefits that can be 

derived from recycling of organic waste into 

compost for use in agriculture, sustainable 

landscapes and other environmental applications 

"Soil is the Solution" might be 

the most important 

environmental story you'll ever 

write. It is part of the solution 

to our environmental 

challenges. The story belongs 

on the front of the NY Times 

Paradigm Shift 

and on 60 Minutes.

- Robert Reed, composting 

manager at Recology, San 

Francisco's waste management 

company Photo courtesy of Larry Strong-Recology

"We take our most precious land and we raise crops at great 

cost. We take our best people — well trained farmers, 

scientists, universities — into a system raising that food. We 

use chemicals and all that junk to raise it. Then we transport 

the food 2,000 miles — another great cost — and then we 

cook it and throw much of it away!

If we allow this to go on any longer, not only are we poisoning 

ourselves with methane, which is a potent greenhouse gas, we 

Paradigm Shift 

fill up our landfills, which we don't have any room for, and 

we're not getting the most precious thing that we raise, high 

mineral value food, back into the soil where it belongs. Now 

that's a full-blown crisis."

- Bob Shaffer

Applying food scrap compost to one acre of land can add 12,000 

pounds of carbon to the soil in one year, taking it out of the 

atmosphere, while conventional farming — tilling the land, using 

commercial fertilizers, etc. — releases 3,700 pounds of carbon 

dioxide into the atmosphere per acre per year. - former Rodale Institute Research Director, Paul Hepperly. 

Paradigm Shift 

Photo courtesy of Larry Strong-Recology

Attachment B

32
10//2012

Paradigm Shift 

Just 3% of the MSW organic fraction is Composted

The SF composting program alone has diverted one 

million tons of waste from landfill disposal. By reducing 

methane, a potent greenhouse gas produced in 

landfills and by sequestering carbon in the topsoil of 

local farms the program has created a total carbon local farms, the program has created a total carbon

dioxide equivalent benefit of more than 305,944 metric 

tons – equal to offsetting emissions from all vehicles 

crossing the Bay Bridge for two years (greenhouse gas 

offsets based on a protocol set by the Climate Action 

Reserve). 

Current Hierarchies

Rethinking the EPA Hierarchy

SOURCE REDUCTION – Reduce the amount of 

organic waste being generated. Leave grass clippings 

in place. Apply manure to fields at appropriate 

agronomic rates. 

FEED PEOPLE– Donate excess food to food banks, 

soup kitchens and shelters.

FEED ANIMALS– Provide food scraps to farmers 

operating environmentally sound and USDA approved 

feeding practices. 

RE-MANUFACTURING – Creates Jobs

Rethinking the EPA Hierarchy

• COMPOSTING – Recycle residuals into a nutrient rich 

soil amendments for their many agronomic benefits, 

Carbon sequestration, groundwater filtering and 

pollutant capture. 

• ENERGY PRODUCTION - Waste to energy via 

anaerobic digestion, with residuals sent to composting; 

incineration/combustion with energy capture and use.

• INDUSTRIAL USE–Fats for rendering; oil for fuel; food 

discards for animal feed production.

GENERATING LANDFILLS – Must consist of Methane 

capture and use for power generation, not just ‘flaring’.

TRADITIONAL LANDFILLING – Disposal with no 

benefits.

Tiers do not consider the following:

 Social benefits like local jobs and local food 

 Overall life cycle analysis and environmental impacts and 

benefits-Carbon Footprint

 Local economies tip fees cost of energy and transportation

Rethinking the EPA Hierarchy

Local economies – tip fees, cost of energy and transportation

 The value of creating end use products and their applications

What’s the value of clean air, clean water and a sustainable 

life style?

There is a need for the development of a local assessment tool 

 Feed the hungry

 Building healthy soils

 Strengthening sustainable food production

 Increasing need for Green Infrastructure

Drivers to Expand Organic Recovery 

Increasing need for Green Infrastructure

 Reducing solid waste costs for communities

 Increasing regulations at the local and state level

 Curbing methane emissions

 Lack of policies to enforce highest and best use practices

 Low cost tipping fees

 Deep pockets of the landfill and incinerator industry to 

lobby effectively for renewable energy subsidies

 Landfill gas recovery companies working to overturn state 

Obstacles to Expand Organic Recovery 

bans on landfill disposal of yard trimmings

 Lack of organic material receiving facilities or 

infrastructure

 Out of date permitting regulations

 Lack of training programs and best practice toolkits for 

commercial, backyard, community and onsite composting;

Attachment B

33
10//2012

 Relocating to our Nations Capital - 2012

 Rejuvenating the Compost Council’s Research & 

Education Foundation - 2012

 Development of Model Rules -2011-2012

 Industry Economic Impact Study -2013-2014

USCC Initiatives 

 Development of State Chapters -2011-2014

 Certification-Operators, Facilities & Product -2013-2014

“A nation that destroys it’s soils, destroys itself”

-Franklin Delano Roosevelt

Attachment B

34