# 1 Landfills NSPS Technical Meeting U.S. EPA, Research Triangle Park, NC Octo ber 22 , 2012

Agenda : Attach ment 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, E PA/LMOP Shaun Ragnauth, EPA/OAP/CCD Alex MacPherson, EPA/ OAQPS David S olomon , EPA/ OAQPS Kathy K aufman EP A/ 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 W uestenberg , Republic Services Ron Strube, Veolia Environmental Services Tomas Carbonell , Environmental Defense Fund Peter Zalzal , Environmental Defense Fund Ruth Mead, ERG Joe Fanj oy, 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 Cr ooks, 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 perspective s on the issues that will be discussed today.

**•** I nput will enable EPA to write the best and most effective regulations for landfills.

**•** An EPA representative asserted that the Agen c y was not attempting to build consensus

.

10:45 AM Ea rly 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:

# 2 **•** A few States are requiring owners/o perators 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 NSP S, is generally not an issue.

**•** Compliance with NSPS oxygen and temperature requirements can be difficult in various early control situations:

o Low

- flow wells in areas where little gas is generated can be difficult to operate while maintaining compliance with the oxygen and temperature requirements.

o If 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.

o When installing or expanding the gas collection and c ontrol system in active

areas , landfills typically use horizontal collect ors for early collection. (Vertical wells are not installed until later with the area is full.) T he 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 l andfill gas energy developers are not interested in inconsistent flows or low

- quality gas.

**•** Site conditions and gas generation determine how the landfill owner/operator manag es the early collection area. It takes time to ramp up to a full NSPS collection system. Ap plication 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
param eters . 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, b ut 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:

**•** Pr ovide 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 area s

.

**•** If EPA were to require earlier collection, industry would need flexibility as the system is installed and operated.

# 3 **•** Provide flexibility regarding when to pull gas from the early collection area. For example, operating the collection and control system intermitte ntly (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 gen eration and could make early collection more difficult.

An EPA representative explained that it c ould 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 Californi a. He said that CalRecycle expects to have data and suggestions on this issue.

A n attendee indicated that the reason for the temperature and oxygen/nitrogen limits in the rule was primarily to prevent landfill fires. Several attendees representing landfil ls 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. M any larg e 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 da ys, but that adding a well can be counter productive 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

T wo presentation s describe d California’s landfill surface monitoring requirements and compare d them to the surface monitoring requirements in the landfills NSPS.

Discussion:

One attendee asse r ted that he would soon have 1 year of data on landfills subject to both the CA rule and t he 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 perspective s on moving away from oxygen and temperature wellhead requirements and relying on enhance d surface monitoring instead.

# 4 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 equipme nt in order to meet the wellhead monitoring parameters (oxygen and temperature). But,

u nder 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 t o begin early actions to reduce greenhouse gases . Early actions speci fically ide ntified 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 ide ntifying emissions

. He stated that t he 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 d ata on measurements above 200 ppmv and will analyze the data and determine if f urther 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 Califo rnia 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 P M Updated k values ba sed on using more detailed landfill gas collection and header pipe data Dr. Morton Barlaz

- NC State University

R esearch 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

# 5 for each landfill area based on scientific judgment . Re sults 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 landfill s 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 respond ed 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 D own – 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 fol lowed.

Only a small group of people have the expertise to do OT M

- 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 metho d ha s 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 land fills.

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. Abatemen t efficiency could be different whether or not oxidation was considered. One attendee sa id t hat 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 quanti fy emissions from landfills. Both have pros and cons.

**•** Both techniques use equipment that is commercially available, requiring software and expertise to operate properly.

# 6 **•** Both techniques can help inform emission estimates and hopefully result in more effe ctive control of landfill gas emissions

.

**•** A dditional 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, m ethane 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

- 1 0. The size and complexity of the landfill layout affects how many days are needed. An EPA representative estimates approximately $20

- 40K per test.

2 : 3 0 PM Landfill Gas Treatment for Beneficial Use Hillary Ward

– USEPA S ector Policies and Programs Divisio n and Amy Ba nister

Waste 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 present ed 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 . W aste M anagement understands that the 2006 proposed n umerical 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 high

Btu 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 s ystems, therefore, do es not have emiss ions

. 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.

# 7 **•** T he 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

man ufacturer’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 trea tment could ma ke 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 a lso requested that EPA retain what was stated in the 20 02 proposed amendments: once the landfill gas has been treated, then there are no further requirements for facilities that buy or use the gas.

Various i ndustry attendees also stated that meeting numerical treatment specifications would be an add itional co st. 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 Manag ement 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 sl ides.

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 f rom both the public and private
sector.

States are starting to focus on e missions from managing organics such as food waste
, specifically odors and methane (greenhouse gas) emissions.

**•** States may require contained composting, rather than windrows

.

**•** Some S tates 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 mana ge than other waste streams. Operators must manage for odors and methane emissions.

**•** Odor control becomes more i mportant as composting facilities move closer to populations

# 8 **•** 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 s ome 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 l arge 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 s tated that landfilling food waste results in lower green house 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 desig n, operation, controls in use, etc. at the landfill and the composting operation.

The second pres e nter presented “ Alternate Compliance Pathways: Composting .” He stressed the importance of considering composting from a broader perspective. Composting is im portant 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 D ivision

4:15 PM Adjourn

# 9 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 Tsir igotis

– 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 O RS 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 Banister

Waste 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 P rograms 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 t l ith O li it

– Diffi cu lt/N o t poss ibl e o comp l y w 2 

## li m it s

– 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

# 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

# California Air Resources Board 10/  /2012



# Landfill Methane Regulation

50,000 Square Foot Grid Walking Pattern

25 feet 200 feet

7250 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

9



## Hydrocarbon Detector Instrument Specifications Renaldo Crooks, Staff Lead rcrooks@arb.ca.gov (916) 327-5618


### Richard Boyd, Manager 

# Contacts

10 

### 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

# 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

• Monitorin g of all cover enetrations
, each p , 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 and multiple ozone non

‐ attainment areas statutes multiple attainment



## • 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 still is important is pretty new; it important to know how things really played out in the field

## 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 CH 4 

## emissions in the U.S. in 2009, accounting for 17% of total CH 4 

## emissions (117.5 Tg CO 2 

## Eq.) (US EPA, 2011).
f f 

## Introduction

 Prediction o methane generation is critical f or

– 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)

– Q n 

### is the CH 4 

### generation rate (m 3 

### /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 ** **

** ** 

#  

**    **  ** ** 

#  

– L 0 

### is the CH 4 

### generation potential (m 3 

### /Mg wet waste);

– M i 

### is waste mass placement in year i (Mg);

– t

ij 

### is age of the j th 

### section of waste mass M i 

### accepted in the i th 

### year (decimal years, e.g., 3.2 years).

3 

##  EPA inventory defaults

– 

### L 0 

### = 100 m 3 

### CH 4 

### /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 m 3 

## /min, but only a 75% probability of 250 m 3 

## /min and a 50% 

## Objectives

75% probability of 250 m /min and a 50% probability of 350 m 3 

## /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

l an dfill prac ti ces: – 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

###  LandGEM re-formulated on a monthly basis

 A collection efficiency factor, α ij 

### , used to convert methane generated to methane collected 

## Estimation of Methane Collection Rates

12 0 

## 12 ** **  ** **

**   ** 

** ** 

## 

**  ** 

#  j i

j k

j ij i 

## k L Q Me

– Q j 

### is the monthly CH 4 

### collection rate (m 3 

### /month) in month j ;

– M i 

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

– α ij 

### is the gas collection efficiency in month j associated with mass deposited in month i ;

– (j-i)/12 is the age of the i th 

### month of waste mass M i 

### in month j (yr).

7 1 

## 12

**** i 

### 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 Jul y - 90 90 40 0 0 0 0 0 0 

### Estimates of α ij 

### 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 α ij 

### from 2006. E ti ti f d d Location of Waste Disposal and Schedule of GCCS Installation at Landfill P2

10 

###  E s ti ma ti on o f α ij 

### d epen d s 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 α ij 

### for Landfill P2 during methane collection months (%)

Months of methane collection 2008 Ma y
Dec 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

11 

## Estimates of Model Parameter - L 0 Waste category Moisture (fraction of total wt.) Methane yield (mL CH 4 /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 L 0 (mL CH 4 /g = m 3 CH 4 /Mg) 54.3 58.2~70.5



###  As an intrinsic property of waste, L 0 

### should range between

55 and 70 m 3 

### CH 4 

### /Mg wet waste. Using optimistic assumptions, we obtain an L 0 

### of 80 m 3 

### CH 4 

### /Mg wet waste.

###  EPA default approach: L 0 

### = 100 m 3 

### CH 4 

### /Mg, k = 0.04 yr -1



### .

 L 0 

### – varied approach:

– Let L 0 

### = 55, 70, 85, and 100 m 3 

### CH 4 

### /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

CH 4 collection data are available for a particular landfill (i.e, months l through m );

• Q calc,j is the calculated monthly methane collection rate,

m 3 /month; and Q meas,j is the measured monthly methane collection rate, m 3 /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+06ne 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 L 0

scenarios give better fits. Note that higher k is required and LandGEM defaults are quite poor.

 If L 0 is allowed to vary with k simultaneously, L 0 will become more like a

fitting parameter rather than representing its physical meaning of methane generation potential. 0.0E+00 2.0E+05Methan

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 NSSE

Landfill ID

 The parameterizations with low L 0 values result in higher errors, while

those with higher L 0 values result in lower errors.

 The SSE for Landfill T at L 0 = 55 m 3 /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 200raction of AP- 42) AP-42 (Lo= 100,k=0.04) Lo= 55 Lo= 70 Lo=85 Lo= 10 0

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 land fill 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 NSSE (Fr

Landfill ID

100 125 150 175 200ve CH4 Collectionof 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 NCumulativ(%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 overestimate s collectable methane for 5 landfills, underestimates for 5 landfills, and matches closely in one case. 

### Cumulative Methane Collection at Each Landfill (site-specific collection α ij 

### )

75 100 125 150e CH4 CollectionfObserved) 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 NCumulativ(% of

Landfill ID varied Lo= 100, optimal k varied Observed0.08 0.10 0.12 0.14 0.16 0.18k(1/yr)

0.08 0.10 0.12 0.14 0.16 0.18k(1/yr) 

### Optimal k Values at L 0 

### = 100 m 3 

### 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 16k

Average Annual Temperature (°C) 0.00 0.02 0.04 0.06 0.08

80 90 100 110 120 130k

Average Annual Precipitation (cm)

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

temperature and precipiation. 

## CH 4 

## generation potential ( L 0 

## ) and corresponding optimized first order waste decay rate ( k ) for landfills

Landfill Leachate recirculation L 0 = 55 L 0 = 70 L 0 = 85 L 0 = 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+06Collection (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+06Collection (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+06Predicted CH4C

Observed CH 4 Collection (m 3 /month) 0.0E+00 2.0E+06

0.0E+00 2.0E+06 4.0E+06 6.0E+06Predicted CH4C

Observed CH 4 Collection (m 3 /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 p lausible ran g e of L 0 

### ( 55-80 m 3 

### CH 4 

### /M g), derived 

## Preliminary Conclusions

p g 0 

### ( 4 

### g), from waste composition data, produce a poor match to the measured data. In contrast, higher L 0 

### values produce a better fit to the data, suggesting these L 0 

### 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

# Questions?

25

# 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 A gr i cu lt ura l opera ti ons, i n d us t r i a l f ug iti ves, 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 i dd i

– ew me th o d s, .e, e y covar ance

• 

### 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 CH 4 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

# 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 C 2 H 2

12 

### Mobile and stationary tracer correlation

y = 0.177x + 0.048

R 2 = 0.881

0.0 0.2 0.4 0.6 0.8 1.0Methane -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

R 2 = 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 EPA NEIC Waste Management

# 10/  /2012

Auto-north met station Quad Sampling Port In the truck : High-precision CH 4 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 co mparison 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 Cen ter, 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 25000Estimate (g/min) Tracer Correlation Emission Estimates by Site (DRAFT 040711)

Working Landfills

17 0 5000 10000

0123456789CH4EmissonE

Landfill Sites bars = +/- 1 stdev revison 1 uncleared draft data, subject to change Closed Landfills

# 10/  /2012

CH 4 

## 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 CH 4 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 t ool of the facility



### • Method used for homogeneous flux

measurements by NOAA and USDA



### • Represents a pe rcentage 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

# 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 bes t 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 L o 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 contra ctor acknowledgments

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

• Nathan Swan, Cygus Environmental

• Eben Thoma, Susan Thorneloe, Bill Squi er, 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

# 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

ARCADIS US Vertical Radial Plume Mapping (VRPM) USA

Finnish Meteorological Institute Micrometeorological Edd y ‐ 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

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

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) "M ethane emissions from 20 landfills across the 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 f l dfill li ti J i 769 776

‐ or l an dfill app li ca ti ons.

. E nv ron. E ng. 136 : – .

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‐2d‐1)

150 200 250

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

Daily Intermediate Final (soil) Final (synthetic)Methane(gm‐

0 50 100 150 

## Intermediate Cover Emission by Climate 20 Landfill OTM

‐ 10 Studym‐2d‐1)

100 120 140 160Methane(gm

0 20 40 60 80

Semiarid Mediterranean Humid Continental

Cool Summer Humid Continental

Warm Summer Humid Subtropical

# 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 LFGCStons

100000 200000 300000 400000tons

100000 200000 300000 400000 SW SE

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

Area (m 2 ) 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 LFGCSe(gCH4/m2/d)

15 20 25

SE SWEmissionRate

0 5 10

CRDS
EPA MRR



## Landfill Characteristics for Closed Landfills without LFGCS

Landfill Area (m 2 ) Waste in Place (tons) k (yr

‐ 1 ) DOC (tons C/ ton

waste)

Center Point 198
, 298 1 ,7 2 98 2 0 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

# 10/  /2012

Waste placement for model

1970 1980 1990 2000 2010 0 100000 200000

Center Point

1970 1980 1990 2000 2010 0 100000 200000ns Seneca East

1970 1980 1990 2000 2010

1970 1980 1990 2000 2010to

0 100000 200000

1970 1980 1990 2000 2010

0 100000 200000 South Wells

Springfield 

## Measured vs. Modeled Emission Rates Closed Landfills without LFG CollectionCH4/m2/d)

15 20 25

CRDS
EPA MRR SWICS

Center Point Seneca East South Wells SpringfieldEmissionRate(gC

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
f ilit i i Additi l h i i d t d td t l d o f ac y em ss ons. Additi ona l researc s requ re o un ers an d empora l an
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

‐ Alternative Natural Technologies Goldsmith Alternative Natural Technologies

• Nathan Swan ‐ Cygnus Environmental Group

• Tom Pike ‐ Pike Contracting

• Environmental Research and Education Foundation

• Republic Industries

• Veolia Environmental Services

• Waste Connections

# 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 t he need for specificity in the

treatment definition

► Contacted manufacture rs 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 ► R ev i ewe d manu f ac t urer ’ s spec ifi ca ti ons f or accep t a bl e l eve l s o f moisture and particulates

4



## Actions After Proposal

► Different manufacturer’s hav e 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 l andfill gas by at least 20 degrees F h h it ith d t i d th l dfill F a h ren h e it w

ith

a d ewa t er

i ng process, an compresses th e l an dfill gas.”
► Selected levels of filtration and de- watering were consistent with

most manufacturer’s specificat ions for landfill gas burned in energy recovery devices

► Protective of combustion equipment and promoted proper

destruction of NMOC
► Treatment system s installed prior to the proposal would be given

1 year to comply with t he 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

# 10/ϮϮ /2012

De-watering

► Continuous monitoring of temper ature reduction for chiller-based

dewatering systems

► Continuous measurement of gas required at treatment system inlet

and chiller outlet unless able to prov e that monitori ng 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 availabl e for the treatment

operating parameters selected

► Data collection required at 15 minut e intervals: consistent with

requirements for flare pilot flame monitoring and enclosed combustor temperature monitori ng 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 r equirements 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 outle t 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 acc ount 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

# 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 loo p s stems y

• 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 t ” d fi iti

rea men t sys em d e fi n iti ons

• Rely on other existing federal rules/standards

for emission control

• Preserve existing site

‐ specific treatment

determinations

# 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% o f f oo d was t e recovere d

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 A d vantages

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 homogenous feedstock.

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 concernsIncreased: acreagdistanc 

# Composting Technologies

ASP

‐ Natural Cover Harvest Power In

‐ Vessel (Tunnel) In

‐ Vessel (Drum)trol, capitalonmental perf.ge, processing time,ce to neighbors

Static Pile ASP

‐ Synthetic Cover ECS/Gore Tech.

Windrow Turning Traditional Windrow ASP

‐ Natural Cover Eng. Compost SystemsIncreased: process contcosts, 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

# 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 environmenta l benefits for our members and society.



## V ision 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 peop le — well trained farmers, scientists, universities — into a sy stem 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 precio us 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 farmi ng — 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

# 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;

# 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