# 1

Date: Decem

ber 12 , 20 1 2

To: Rachel Schmeltz , U.S. EPA

From: Jeff Coburn and Kate Bronstein, RTI International

Subject: Review of Methane Flux and Soil Oxidation Data

Purpose

This memorandum documents the review of the methane oxidation fraction options presented in

the Solid Waste Industry for Climate Solutions (SWI CS) Methane Oxidation Addendum 2012,

dated November 19, 2012 (SWICS, 2012) given the met hane flux data provided by industry

representatives.

Background

As methane generated in the landfill flows up throu gh a landfill’s cover soil, a fraction of that

methane will be oxidized or metabolized by methanot rophic bacteria near the soil surface. The

relative amount of methane removed from the landfil l gas stream as the gas passes through the

soil surface layer is termed the fraction oxidized or oxidation fraction. The fraction oxidized

depends on a number of factors including:

• The flow velocity of landfill gas, or the methane f lux, through the soil surface (higher

flux rates means lower residence times in the aerob ic soil layer and less oxidation),

• The porosity of the soil layer (greater porosity le ads to more air ingress and a thicker

aerobic soil layer, which leads to more oxidation),

• The number and types of microorganisms in the surfa ce soil layer, and

• The soil surface temperature and moisture, which ma y increase or inhibit microbial

activity.

40 CFR Part 98 Subpart HH of the EPA’s Greenhouse G as Reporting Program requires owners

and operators of municipal solid waste (MSW) landfi lls to use an oxidation fraction of 10

percent when estimating methane emissions from MSW landfills. Industry representatives have

commented that the 10 percent oxidation fraction is too low and that many landfills have much

higher oxidation fractions as shown in the recent p ublished literature. Consequently, MSW

landfill representatives state that the emissions r eported under Subpart HH are biased high. The

industry representatives compiled data from publish ed studies and evaluated soil oxidation

fractions in an addendum report (SWICS, 2012) to su pport their statement and provide options

for using the data to estimate the oxidation fracti on for MSW landfills reporting under Subpart

HH. This memorandum summarizes these options, provi des a comparison of methane emissions

that would be reported using these options based on methane flux data provided by industry

representatives, and provides recommendations for s electing a specific option for inclusion in

Subpart HH to replace the current 10 percent defaul t oxidation fraction requirement.

# 2

Summary of Options

The current requirement for Subpart HH and options proposed by the industry representatives in

the Addendum (SWICS, 2012) are summarized below, followed by an analysis of each option.

• Option 0 . Use an oxidation fraction of 10 percent. This is the cur rent situation for

Subpart HH, where owners and operators of MSW landfills are required to use an

oxidation fraction of 10 percent.

• Option 1 . Use a revised standard default oxidation fraction for al l landfills based on

published literature included in the Addendum (SWICS, 2012). The m edian oxidation

fraction for all studies included in the SWICS Addendum was 0.33; the arithmetic

average was 0.38.

• Option 2 . Use a standard default oxidation fraction for a given s oil cover type. For

landfills that have areas (that contain waste) withdifferent soil cover types, an areaweighted oxidation fraction would be calculated for use. Th e median and arithmetic

average oxidation fractions for different soil types pres ented in the SWICS Addendum

are summarized in Table 1

.

Table 1. Median and Arithmetic Average Methane Oxidation Frac tions (SWICS,

2012)

Cover Type Arithmetic Average

Oxidation Fraction Median Oxidation

Fraction

Organic Cover 0.38 0.37

Clay Cover 0.30 0.29

Sand Cover 0.54 0.50

Other Mixtures 0.36 0.30

• Option 3 . Use a default methane oxidation rate based on the soi l cover type. This

approach would require landfills that have areas containing waste with different soil

cover types to calculate an area-weighted methane oxida tion rate to use. If the methane

oxidation rate exceeds the methane flux, then the frac tion oxidized would be 1;

otherwise, the fraction oxidized would be calculated as t he methane oxidation rate

divided by the methane flux rate. Based on the summary dat a contained in the SWICS

Addendum, the default methane oxidation rates by cover type are shown in Table 2

.

# 3 Table 2. Default Methane Oxidation Rates by Cover Type (SWICS, 2012)

Cover Type Arithmetic Average Methane Oxidation

Rate (g/m 2 

# /d)

Organic Cover 4.0

Clay Cover 7.6

Sand Cover 5.2

Other Mixtures 5.8

Note: g/m 2 

# /d = grams per square meter per day



# • Option 4 . Use a binned approach where the average oxidation fracti on is determined for

landfills based on the methane flux rate of the landf ill. In the SWICS Addendum, one

average oxidation fraction was to be determined using all st udy data that for

landfills/columns with low methane flux rates (less than 10 g/m 2 

# /d), a second oxidation

fraction was determined using study data for landfills/colu mns with medium methane

flux rates (10 to 70 g/m 2 

# /d), and a third oxidation fraction was determined using study

data for landfills/columns with high methane flux rate s (greater than 70 g/m 2 

# /d). The

binned approach factors are shown in Figure 1 (from Figure 5 from SWICS, 2012).

Table 3 summarizes these values along with the correspon ding central tendency value

used in the analysis of the industry-supplied data.

Figure 1. Methane oxidation percent as a function of methane e missions.

Mean values are shown with standard error and median val ues below. (Figure 5 from

SWICS, 2012).

# 4 Table 3. Binned Approach to Methane Oxidation Fraction

Bin Number and

Description Arithmetic

Average Oxidation

Fraction Median

Oxidation

Fraction Central Tendency

Oxidation

Fraction Used

Bin 1: Flux <10 g/m 2 

# /d 0.384 0.335 0.35

Bin 2: Flux of 10-70

g/m 2 

# /d 0.274 0.210 0.25

Bin 3: Flux >70 g/m 2 

# /d 0.124 0.077 0.10

Note: g/m 2 

# /d = grams per square meter per day



# Implications of These Options to Subpart HH

Option 1 would only require a revision of the default oxidati on fraction in Subpart HH and

would be simple to adopt. However, as described in the Bac kground, many factors influence the

oxidation fraction for a given landfill and using a single default factor for all landfills does not

take these factors into consideration.

Option 2 accounts for differences in soil type and would be fairly straightforward to implement

in the rule. Each reporting facility would have to dete rmine an area-weighted oxidation fraction,

much like the area-weighted landfill gas collection eff iciency determined via Table HH-3 to

Subpart HH. However, this method does not account for diff erences in methane flux rates. It is

logical that if two landfills had identical methane generation and soil cover types, but one had a

gas collection system while the other did not, the landf ill with the gas collection system would

have a lower methane flux rate through the surface soi l, resulting in a longer residence time for

the gas in the surface soil layer and greater methane oxi dation. The soil-specific default

oxidation fractions do not account for this variability. W ith the exception of the sand oxidation

fractions, the other oxidation fractions do not appear to va ry significantly with soil type. Using a

method that is solely dependent on soil type does not appear to account for differences in

methane flux rates, which, based on the oxidation fracti ons in the binned approach (Option 4), is

a more important factor influencing the oxidation fraction

.

Option 3 would be the most complicated method to implement in the rule. This option requires

the calculation of both an area-weighted methane oxidatio n rate and the methane flux rate in

order to calculate the oxidation fraction. Based on the proposed calculation of the oxidation

fraction using the default oxidation rates in Table 2, this approach may yield a high bias due to

the simplified assumption made about the oxidation rate ( represented by the dotted line in the top

graph of Figure 2 , which would generally lie above the actual oxidation rate represented by the

curved line). Furthermore, there appears to be high variabil ity and uncertainty in the default

factors presented in the SWICS Addendum. For example, t he mean methane oxidation rate from

column studies for sand covers was 10 g/m 2 

# /d, while the mean methane oxidation rate for field

studies of sand covers was only 0.30 g/m 2 

# /d, leading to an arithmetic mean of 5.2 g/m 2 

# /d.

Additionally, the default methane oxidation rate for cl ay covers is higher than for any other soil

covers, even though clay covers have the lowest average default oxidation fraction under

# 5

Option 2. It appears that the measured methane oxidation ra te was more of a function of the

methane flux rate at the landfill, where facilities with high methane fluxes yielded high methane

oxidation rates, but not necessarily different oxidation fractions.

Figure 2. Modeled relationships between methane oxidation rat e and percent oxidation as a

function of methane loading to the landfill cover (Figure 2 fr om SWICS, 2012).

Option 4 is somewhat complicated to implement in the rule because it requires a calculation of

the methane flux rate in order to determine the appropr iate binned methane oxidation fraction to

use. Once the appropriate bin is determined for the landfil l, the default oxidation fraction for the

landfill is established with no other soil type considera tions. While this approach does not

consider soil type, the majority of landfills (based on the industry-supplied data) use clay or

“other mixtures” for their soil covers. When consideri ng these soil cover types, there does not

appear to be a significant influence of cover type on the oxidation fraction. On the other hand,

there are significant differences in the oxidation frac tion determined for the landfills/soil column

tests with different methane flux rates, suggesting the methane flux rate is likely more important

than the soil cover type in influencing the methane oxid ation fraction. The binned approach

# 6

would tend to yield higher oxidation fractions for faciliti es with gas collection systems (because

they would have lower methane flux rates) and for clos ed landfills where the gas production

rates are expected to temporally decline.

Industry-Provided Data Analysis and Results

MSW landfill representatives provided data for 262 landfill s currently reporting under Subpart

HH. The dataset included an indication as to whether th e landfill was open (active) or closed, an

indication of the presence of a landfill gas collectio n system, the annual methane generation

determined by Equation HH-1, the annual methane recovery de termined by Equation HH-4, the

back-calculated annual methane generation (R/CE/f_REC as used Equation HH-7), the total area

of the landfill containing waste at the start of the r eporting year, and the areas of waste

corresponding to the area types in Table HH-3. These data were used to determine the impact of

the different methane oxidation options discussed earlier in this memorandum on the methane

emissions. The majority of the dataset consisted of o pen landfills (208 of 262 landfills, or 80

percent). Additionally, 221 (or 84 percent) of the landfill s indicated the presence of a landfill gas

collection system. A listing of the industry-provided dat a is included in Attachment 1 to this

memorandum.

Methane flux rates (methane generation minus methane r ecovery) were calculated for each

landfill with a gas collection system using the reporte d methane recovery rates and backcalculated methane generation rates [i.e., R/(CE×f Rec 

# )]. For landfills with gas collection systems,

the net methane flux rate can be determined using two met hods corresponding to Equations HH6 and HH-8 in Subpart HH. To compare the different methan e oxidation fraction options, a

single methane flux rate was needed. Therefore, the f ollowing logic was used to predict which

equation (HH-6 versus HH-8) the facility would use in repor ting their rollup emissions. Equation

HH-8 was assumed to be used if (1) the methane recovery divided by 0.95 (maximum expected

collection efficiency) was greater than the methane ge neration determined by Equation HH-1, or

(2) the back-calculated methane generation rate [i.e., R /(CE×f

Rec 

# )] was less than the methane

generation determined by Equation HH-1. Equation HH-6 was assu med to be used if neither of

the two previously mentioned conditions were met.

For facilities where Equation HH-8 was assumed to be used, the methane flux was calculated as

[R/(CE×f

Rec 

# ) –R]/SA, where R= annual quantity of methane recovered in gas collection system

(metric tons/year), CE is the collection efficiency of the gas collection system, f Rec 

# = fraction of

time the collection system operated during the year, an d SA = surface area of the landfill

containing waste (m 2 

# ). For facilities where Equation HH-6 was assumed to be us ed, the methane

flux was calculated as (G CH4 

# –R)/SA, where GCH4 = annual methane generation determi ned

using Equation HH-1 (metric tons/year). For facilities without gas collection systems, the

methane flux was calculated as G CH4 

# /SA . The flux rates were then converted to the appropria te

units (g/m

2 

# /d) noting that there are 1,000,000 grams/metric ton and 365 days /year.

Table 4 presents the methane emissions that would be reported across the dataset for the

different options evaluated. To determine the amount of m ethane oxidized and the cumulative

methane emissions, the median values reported in the SWICS Addendum were used for

# 7

Options 1 and 2; the mean value reported in the SWICS Addendu m was used for Option 3 1 

# ; and

the default oxidation fraction selected between the mea n and median values for Option 4 (i.e., the

last column of Table 3). Option 0 is the “before” situa tion, while Options 1 through 4 are the

“after” situations.

Table 4. Cumulative Methane Emissions Calculated Using Diff erent Options for

Estimating Methane Oxidation

Option Cumulative CH 4 

# Emissions for Landfills

in the Dataset (metric tons/yr)

Option 0: Default OX = 0.1 754,630

Option 1: Default OX = 0.33 572,066

Option 2: Default OX by soil cover type 587,197

Option 3: Default oxidation rates 553,054

Option 4: Default OX by methane flux bin 642,123

Option 1 results in lower emissions than Option 0 because a higher fixed oxidation fraction for

all landfills was applied. Option 2 yields higher emission s than Option 1 because 79 percent of

the landfills in the dataset had clay or “other mixtur e” soil covers. When weighted by methane

generation, clay and “other mixture” soil covers represe nted 87 percent of the total methane

generation. The SWICS Addendum included a higher fraction of organic and clay cover studies,

resulting in a slightly higher average oxidation fraction than would be calculated if the number of

tests per cover type more closely matched the cover ty pes reported by the landfills in the

industry-supplied dataset.

Option 3 resulted in the lowest emissions. A slightly hi gh bias in the calculated oxidation

fraction is expected for this option because it essent ially uses two straight lines to mimic the

oxidation curve, with the actual oxidation curve lying genera lly on or below these straight lines.

The binned approach (Option 4) yields the highest emissions c ompared to Options 1 through 3.

A large portion of the landfills in the dataset have me thane flux rates that fall under Bin 2,

meaning that a significant portion of the landfills are assigned a default oxidation fraction of

0.25, which is lower than the default soil oxidation fract ions by soil type and the single

aggregated default value. Table 5 summarizes the assigned bins for landfills based on th e

presence of a landfill gas collection system. Although t here are a limited number of landfills in

the dataset without a landfill gas collection system, it appears that these landfills are much more

likely to fall under Bin 3 than landfills with gas coll ection systems. The only landfill without a

landfill gas collection system that was assigned to B in 1 was a closed landfill. It seems

reasonable that closed landfills, where methane generat ion rates are assumed to decrease over

time, can have higher oxidation fractions as the methan e flux rates decrease.

1 

# For Option 3, only the arithmetic average (mean) was reported in the SWICS Addendum. We expect that the

median value is less than the arithmetic average, but sinc e the median was not reported, only the mean could be used

for Option 3.

# 8 Table 5. Breakdown of Landfills by Methane Oxidation Flux Bin

Bin/Description Number of

Landfills in Bin

With No GCS 1 

# Number of

Landfills in

Bin With GCS 1 

# Cumulative

Number of

Landfills in

Bin

Bin 1: Flux <10 g/m 2 

# /d (OX=0.35) 1 78 79

Bin 2: Flux of 10-70 g/m 2 

# /d (OX=0.25) 31 142 173

Bin 3: Flux >70 g/m 2 

# /d (OX=0.10) 9 1 10

1 

# GCS = Gas collection system

Conclusions/Recommendations

• Observed methane oxidation fractions for landfills of th e same cover soil type are highly

variable, but the average oxidation fractions for differe nt soil cover types are all well

above 0.10 (the default currently required to be used in 40 CF R part 98 subpart HH).

These data suggest that the current default oxidation frac tion in subpart HH is biased low,

and should be revised.

• Shifting from a 10 percent oxidation fraction to any of the four options considered in this

memorandum will lower the methane emissions reported un der Subpart HH.

• For the cover soil types most commonly used at landfill s (clay and “other” soil covers),

the methane flux rate appears to be a much more importan t factor influencing the

oxidation fraction than soil type. Furthermore, a signif icant portion of the field oxidation

studies, particularly for these common cover soil types , were conducted at landfills with

gas collection systems. The average oxidation fraction determined for these cover types

may not be representative of landfills without gas coll ection systems, which are expected

to have higher methane flux rates than landfills with gas collection systems. Therefore,

the average oxidation fraction (across all soil types or varied by soil type – Options 1 and

2) are not recommended for use in Subpart HH.

• The oxidation rate data were highly variable, and the most direct means of applying this

method (Option 3) is expected to have a high bias on the estimated methane oxidation

fractions. Therefore, using a set methane oxidation rat e by soil type (Option 3) is not

recommended for use in Subpart HH.

• Utilizing an average oxidation fraction based on the meth ane flux “bin” (Option 4)

provides a means to account for the impact of the methan e flux rate on the fraction

oxidized, which appears to have a greater influence on the o xidation fraction than soil

type. The “binned” approach (Option 4) is consistent with t he current default oxidation

fraction of 0.10 for landfills with high methane flux r ates, but provides for higher

oxidation fractions for landfills with lower methane f lux rates, regardless of whether the

lower flux rate is due to methane recovery or decrease d methane generation (as is typical

for close landfills). As such, the binned” approach (Op tion 4) is recommended for

inclusion in Subpart HH for all landfills.

# 9

References

Solid Waste Industry for Climate Solutions (SWICS), 2012. SWICS 2.2 Methane Oxidation

Addendum 2012 . Addendum to the “Current MSW Industry Position and Sta te-of-thePractice on LFG Collection Efficiency, Methane Oxidatio n, and Carbon Sequestration in

Landfills.” Prepared for Solid Waste Industry for Clima te Solutions (SWICS); prepared

by SCS Engineers. Version 2.2, Revised January 2009. Addendum is dated November

19, 2012.

# A-1 Attachment 1

MSW Landfill Methane Generation, Recovery, and Surface Area D ata Supplied by

Industry Representatives for Evaluation of Methane Oxidation A lternativesA-2**Industry-Supplied Data for Methane Oxidation Analys is** **Fac_ID Open_flag** **GCS_flag G_CH4** **(MT) R** **(MT) R/CE/f_Rec** **(MT) Total** **Area********waste (m** **2 )** **Area1 (organic)** **(m 2** **) Area2** **(Clay) (m** **2 )** **Area3 (Sand)** **(m 2** **) Area4** **(other) (m** **2 )** LF 001 Open Yes 17,666 19,201 24,253 542,298 - 542,298 - -LF 002 Open No 3,057 - - 231,488 - 231,488 - -LF 003 Open Yes 10,533 8,523 12,580 398,225 - 373,943 - 24,282LF 004 Open Yes 8,759 16,503 20,111 433,838 - 173,616 - 260,222LF 005 Open Yes 7,058 2,728 7,621 326,188 - 326,188- -LF 006 Closed Yes 8,993 1,110 1,210 263,055 - - - 263,055LF 007 Open Yes 14,783 10,800 17,570 457,311a- 449,217 - -LF 008 Open Yes 26,720 12,206 17,542 562,533 - 562,533 - -LF 009 Open Yes 38,592 11,466 14,252 738,982 - 91,058 647,925 -LF 010 Open Yes 12,594 5,885 7,446 415,627 - 415,627 - -LF 011 Open Yes 4,315 1,990 2,808 286,932 - - 286,932 -LF 012 Closed Yes 574 1,062 2,249 206,397 - - - 206,397LF 013 Open Yes 14,237 6,895 8,568 278,029 191,01887,011 - -LF 014 Open Yes 13,813 7,541 9,031 305,549 162,285143,264 - -LF 015 Open Yes 18,541 13,646 15,588 573,460 203,564 369,896 - -LF 016 Open Yes 15,634 9,252 10,713 554,439 196,280358,160 - -LF 017 Open Yes 4,537 2,726 3,992 158,238 - - - 158,238LF 018 Open Yes 3,416 3,113 4,008 147,716 - 147,716- -LF 019 Open Yes 20,391 15,519 22,748 479,570 - 106,436 - 373,133LF 020 Closed Yes 2,523 3,320 3,720 277,220 - 119,387 - 157,833LF 021 Open Yes 11,184 2,305 4,130 337,115 - 337,115 - -LF 022 Open Yes 27,615 11,637 14,347 497,781a- 188,995 300,692 -LF 023 Open Yes 11,332 6,467 11,102 458,930 - 257,794 - 201,136A-3**Industry-Supplied Data for Methane Oxidation Analys is** **Fac_ID Open_flag** **GCS_flag G_CH4** **(MT) R** **(MT) R/CE/f_Rec** **(MT) Total** **Area********waste (m** **2 )** **Area1 (organic)** **(m 2** **) Area2** **(Clay) (m** **2 )** **Area3 (Sand)** **(m 2** **) Area4** **(other) (m** **2 )** LF 024 Open No 4,473 - - 162,689 - 162,689 - -LF 025 Closed Yes 3,261 1,104 1,197 250,914 - 250,914 - -LF 026 Open Yes 29,535 32,652 35,250 783,095 - 756,789 - 26,306LF 027 Open Yes 28,731 13,227 21,535 708,225a- - - 700,131LF 028 Open Yes 7,588 3,876 8,375 214,896 - 206,8028,094 -LF 029 Open No 2,460 - - 84,178 - 80,131 - 4,047LF 030 Open Yes 6,397 2,695 3,086 353,708 108,055 245,653 - -LF 031 Open Yes 32,877 13,125 14,765 616,358 - 533,395 - 82,964LF 032 Open Yes 11,605 9,151 10,827 570,222 - 471,476 - 98,747LF 033 Open Yes 6,559 3,810 5,423 297,455 - 285,314- 12,141LF 034 Closed No 1,642 - - 198,303 - - - 198,303LF 035 Open Yes 16,683 8,638 10,888 373,133 243,225129,909 - -LF 036 Open Yes 9,084 8,557 9,926 562,128 230,679 331,449 - -LF 037 Open Yes 7,874 5,200 10,321 279,243 - 279,243 - -LF 038 Open Yes 9,009 3,847 7,878 279,243 - 279,243- -LF 039 Open No 1,820 - - 91,058 - - - 91,058LF 040 Open No 2,222 - - 133,551 - 78,512 - 55,039LF 041 Open Yes 12,374 6,492 11,163 548,369a- - - 426,959LF 042 Open Yes 14,679 10,679 13,117 691,228 350,875 12,141 - 328,212LF 043 Open Yes 48,974 8,202 11,736 2,760,054 - 2,751,960- 8,094LF 044 Open No 5,252 - - 370,301 - - - 370,301LF 045 Open No 4,678 - - 301,906 - - - 301,906LF 046 Open Yes 9,235 7,757 14,220 410,771 - 410,771 - -A-4**Industry-Supplied Data for Methane Oxidation Analys is** **Fac_ID Open_flag** **GCS_flag G_CH4** **(MT) R** **(MT) R/CE/f_Rec** **(MT) Total** **Area********waste (m** **2 )** **Area1 (organic)** **(m 2** **) Area2** **(Clay) (m** **2 )** **Area3 (Sand)** **(m 2** **) Area4** **(other) (m** **2 )** LF 047 Closed Yes 2,514 1,695 2,260 242,820 - - - 242,820LF 048 Open Yes 16,939 12,571 17,105 482,807 - 478,760 - 4,047LF 049 Open Yes 41,360 22,242 26,887 701,750 - 393,368 - 308,381LF 050 Closed Yes 12,699 8,635 10,358 445,170 - - -445,170LF 051 Open Yes 8,908 5,707 7,484 336,306 - 328,212- 8,094LF 052 Open No 5,024 - - 169,974 - 169,974 - -LF 053 Open No 5,844 - - 182,520 - 182,520 - -LF 054 Open Yes 6,172 1,406 2,518 297,859 - 297,859- -LF 055 Open Yes 69,221 22,704 28,860 1,173,630 - 1,157,442- 16,188LF 056 Open No 2,244 - - 161,880 - 161,880 - -LF 057 Open No 2,917 - - 161,880 - 161,880 - -LF 058 Open Yes 5,284 4,919 8,589 230,679 - 60,705169,974 -LF 059 Open No 4,076 - - 202,350 - 174,021 - 28,329LF 060 Open Yes 15,095 10,270 12,436 335,092 95,50994,700 112,507 32,376LF 061 Open Yes 14,256 12,612 14,404 303,525 36,42361,110 153,786 52,206LF 062 Open Yes 8,575 7,144 7,946 218,538 52,611 37,232 120,601 8,094LF 063 Open Yes 2,434 158 234 237,964 - 237,964 - -LF 064 Open No 5,419 - - 157,833 8,094 149,739 - -LF 065 Open No 3,563 - - 258,199 - 256,175 - 2,024LF 066 Open Yes 7,635 8,817 11,518 333,068 - 300,692 - 32,376LF 067 Open Yes 1,547 187 752 146,501a- - 140,431 -LF 068 Open No 2,723 - - 150,548a- 146,501 - -LF 069 Open No 3,750 - - 210,444 - 210,444 - -A-5**Industry-Supplied Data for Methane Oxidation Analys is** **Fac_ID Open_flag** **GCS_flag G_CH4** **(MT) R** **(MT) R/CE/f_Rec** **(MT) Total** **Area********waste (m** **2 )** **Area1 (organic)** **(m 2** **) Area2** **(Clay) (m** **2 )** **Area3 (Sand)** **(m 2** **) Area4** **(other) (m** **2 )** LF 070 Closed Yes 8,400 7,338 7,728 321,332 321,332- - -LF 071 Open Yes 4,832 2,873 3,210 427,363 90,653 336,710 - -LF 072 Open No 12,850 - - 331,854 - 331,854 - -LF 073 Open Yes 68,244 10,961 16,827 830,444 - 830,444 - -LF 074 Open Yes 25,165 16,760 26,856 870,105 - 870,105 - -LF 075 Closed Yes 16,202 6,597 9,028 429,387 - - -429,387LF 076 Open No 5,023 - - 180,901 - 180,901 - -LF 077 Open Yes 9,862 5,204 8,489 394,583 - 394,583- -LF 078 Open Yes 4,574 527 5,438 230,679 - 230,679 --LF 079 Open Yes 17,437 10,945 16,157 560,105 - 560,105 - -LF 080 Open Yes 10,067 9,225 12,433 465,405 - 465,405 - -LF 081 Open Yes 8,442 3,998 9,556 351,684 - 351,684- -LF 082 Open Yes 7,705 10,038 14,996 336,710 - - 336,710 -LF 083 Open Yes 3,377 4,626 6,014 176,449 - 52,611123,838 -LF 084 Open Yes 8,998 3,935 6,427 242,415 - 242,415- -LF 085 Open Yes 8,437 3,973 7,487 378,395 - 378,395- -LF 086 Open Yes 31,948 12,899 21,843 565,366 - 565,366 - -LF 087 Open Yes 5,448 3,291 4,449 304,334 - - - 304,334LF 088 Open Yes 9,944 3,458 5,715 275,196 - 275,196- -LF 089 Open Yes 8,932 6,747 10,173 271,149 - 97,128- 174,021LF 090 Open No 7,706 - - 254,961 - 254,961 - -LF 091 Open Yes 15,201 5,354 7,614 501,828 - 501,828 - -LF 092 Open No 4,892 - - 150,548 - 126,266 - 24,282A-6**Industry-Supplied Data for Methane Oxidation Analys is** **Fac_ID Open_flag** **GCS_flag G_CH4** **(MT) R** **(MT) R/CE/f_Rec** **(MT) Total** **Area********waste (m** **2 )** **Area1 (organic)** **(m 2** **) Area2** **(Clay) (m** **2 )** **Area3 (Sand)** **(m 2** **) Area4** **(other) (m** **2 )** LF 093 Open Yes 11,698 2,472 3,522 415,222 - 138,003 - 277,220LF 094 Open Yes 7,862 6,849 10,243 242,820 - 242,820 - -LF 095 Open Yes 31,367 7,965 10,824 1,112,925 - 4,047 1,108,878-LF 096 Open Yes 17,538 12,589 16,509 348,042 - 348,042 - -LF 097 Closed Yes 10,801 2,533 3,536 971,280 - - -971,280LF 098 Open Yes 8,695 2,621 3,443 350,470 - 350,470- -LF 099 Closed No 2,434 - - 285,314 - 285,314 - -LF 100 Open Yes 25,111 9,983 13,013 581,149 - 581,149 - -LF 101 Open Yes 33,248 20,248 29,742 489,687 - 69,608 - 420,079LF 102 Open Yes 4,695 3,029 3,726 177,259 106,031 71,227 - -LF 103 Open Yes 7,546 1,494 2,732 174,021a- 169,974 - -LF 104 Open Yes 26,678 8,993 13,748 460,953 - 460,953 - -LF 105 Open Yes 6,241 7,355 9,394 196,684 - 196,684- -LF 106 Open No 2,986 - - 420,888 - 210,444 24,282 186,162LF 107 Open Yes 43,173 29,001 39,297 788,356a40,470 - - 681,515LF 108 Open Yes 52,884 13,807 19,487 1,033,604a- 128,695 - 894,792LF 109 Closed Yes 6,567 2,187 2,325 416,841 - - - 416,841LF 110 Closed Yes 2,992 1,010 1,362 999,609 - - - 999,609LF 111 Closed No 1,935 - - 161,880 - - - 161,880LF 112 Closed No 1,565 - - 445,170 - - - 445,170LF 113 Closed Yes 2,108 621 938 323,760 - - - 323,760LF 114 Closed Yes 1,295 219 360 335,901 - - - 335,901LF 115 Closed Yes 2,940 3,952 5,288 364,230 - - - 364,230A-7**Industry-Supplied Data for Methane Oxidation Analys is** **Fac_ID Open_flag** **GCS_flag G_CH4** **(MT) R** **(MT) R/CE/f_Rec** **(MT) Total** **Area********waste (m** **2 )** **Area1 (organic)** **(m 2** **) Area2** **(Clay) (m** **2 )** **Area3 (Sand)** **(m 2** **) Area4** **(other) (m** **2 )** LF 116 Closed Yes 8,729 1,954 2,606 611,097 - - - 611,097LF 117 Closed Yes 2,706 689 866 295,431 - - - 295,431LF 118 Open No 4,054 - - 793,212 - - 793,212 -LF 119 Open Yes 16,040 13,757 21,539 900,458 3,642896,815 - -LF 120 Open Yes 23,184 14,943 18,508 342,781 - 334,687 - 8,094LF 121 Open No 2,309 - - 152,572 - - - 152,572LF 122 Open Yes 13,346 5,989 8,096 539,465 - - 539,465 -LF 123 Open Yes 3,979 3,104 5,806 301,502a- 277,220 - -LF 124 Open Yes 10,201 10,362 14,687 372,324 - 372,324 - -LF 125 Open No 3,137 - - 271,958 - 271,958 - -LF 126 Open Yes 6,646 1,057 4,479 360,183 - 352,0898,094 -LF 127 Closed No 1,445 - - 117,363 - - - 117,363LF 128 Closed No 1,492 - - 178,068 - - - 178,068LF 129 Closed Yes 1,115 2,161 2,366 311,619 - - - 311,619LF 130 Closed No 1,196 - - 226,632 - - - 226,632LF 131 Closed Yes 2,252 935 1,311 315,666 - - - 315,666LF 132 Closed Yes 2,663 1,804 2,596 178,068 - - - 178,068LF 133 Closed Yes 2,135 1,171 2,455 445,170 - - - 445,170LF 134 Closed Yes 1,317 826 1,152 343,995 - - - 343,995LF 135 Open Yes 2,339 1,168 2,570 177,259 - 176,045- 1,214LF 136 Open Yes 7,769 6,276 8,474 377,585 - 377,585- -LF 137 Open Yes 10,572 12,521 16,159 348,042 - - 348,042 -LF 138 Open Yes 16,534 14,375 20,303 453,264 241,201 38,042 20,235 153,786A-8**Industry-Supplied Data for Methane Oxidation Analys is** **Fac_ID Open_flag** **GCS_flag G_CH4** **(MT) R** **(MT) R/CE/f_Rec** **(MT) Total** **Area********waste (m** **2 )** **Area1 (organic)** **(m 2** **) Area2** **(Clay) (m** **2 )** **Area3 (Sand)** **(m 2** **) Area4** **(other) (m** **2 )** LF 139 Open Yes 1,465 970 1,669 91,462a- - 75,274 -LF 140 Open Yes 6,024 3,998 5,766 418,865 - 315,666- 103,199LF 141 Open Yes 47,133 43,154 57,538 906,528 - 906,528 - -LF 142 Open Yes 11,776 7,337 9,296 362,207 - 341,972 20,235 -LF 143 Closed Yes 5,334 1,616 1,728 205,992 - - - 205,992LF 144 Open Yes 2,830 1,246 1,639 134,765 - 122,62412,141 -LF 145 Open Yes 4,957 2,480 3,123 242,820 26,306 -169,569 46,945LF 146 Open No 1,801 - - 212,872 - - - 212,872LF 147 Closed Yes 3,184 2,528 3,284 404,700 - - - 404,700LF 148 Open Yes 15,589 17,433 25,026 364,230 - 364,230 - -LF 149 Closed Yes 26,770 9,520 10,931 1,100,784 - 959,139 - 141,645LF 150 Open Yes 12,080 10,832 14,074 449,217 - 169,974 - 279,243LF 151 Closed Yes 12,321 19,620 26,950 1,165,536 -- - 1,165,536LF 152 Closed Yes 11,236 10,251 10,790 416,841 - -- 416,841LF 153 Open Yes 30,321 20,238 26,082 748,695 - 157,833 80,940 509,922LF 154 Open Yes 6,385 2,317 3,413 481,188 - - - 481,188LF 155 Open Yes 19,109 20,500 25,037 1,133,160 - 1,133,160- -LF 156 Open Yes 13,433 12,082 13,933 360,183 - 242,820 117,363 -LF 157 Open Yes 19,910 11,190 20,157 384,465 - 384,465 - -LF 158 Open Yes 38,410 26,045 30,064 793,212 - 469,452 - 323,760LF 159 Open Yes 10,001 4,123 5,441 387,298 - 387,298 - -LF 160 Open Yes 25,721 6,688 8,986 468,238 - 468,238 - -LF 161 Open Yes 10,496 8,955 11,269 431,006 - 105,222 - 325,784A-9**Industry-Supplied Data for Methane Oxidation Analys is** **Fac_ID Open_flag** **GCS_flag G_CH4** **(MT) R** **(MT) R/CE/f_Rec** **(MT) Total** **Area********waste (m** **2 )** **Area1 (organic)** **(m 2** **) Area2** **(Clay) (m** **2 )** **Area3 (Sand)** **(m 2** **) Area4** **(other) (m** **2 )** LF 162 Closed Yes 7,193 5,070 5,385 263,055 - - - 263,055LF 163 Open Yes 7,266 5,418 9,168 367,063 - - 63,133 303,930LF 164 Open Yes 17,876 9,850 12,952 497,376 - 174,021 - 323,355LF 165 Open Yes 6,134 2,713 6,049 222,180 - 197,898- 24,282LF 166 Closed Yes 26,933 13,352 14,112 526,110 - -- 526,110LF 167 Open Yes 11,813 2,871 4,973 523,277 - 523,277 - -LF 168 Open Yes 4,864 5,582 6,763 218,538 117,363 -- 101,175LF 169 Closed Yes 4,010 646 780 283,290 - - - 283,290LF 170 Open Yes 56,119 33,064 44,004 831,659 - 831,659 - -LF 171 Open Yes 39,798 33,695 41,471 828,826 - 103,603 138,407 586,815LF 172 Open Yes 23,121 9,001 11,941 744,648 - 744,648 - -LF 173 Open No 1,727 - - 145,692 - 145,692 - -LF 174 Open Yes 17,831 2,117 2,673 439,504 - 407,128 - 32,376LF 175 Open Yes 20,829 10,098 19,160 651,567 - 103,603 547,964 -LF 176 Open Yes 42,480 19,451 32,377 817,494 - 817,494 - -LF 177 Open Yes 18,035 7,284 10,770 488,878 - 488,878 - -LF 178 Open Yes 23,631 3,861 10,699 486,045 - - 26,306 459,739LF 179 Open Yes 37,137 12,117 15,638 586,410 - - 586,410 -LF 180 Closed Yes 7,934 3,232 3,503 651,567 - 441,123 210,444 -LF 181 Closed Yes 3,916 3,150 3,330 343,995 - - - 343,995LF 182 Open Yes 62,216 25,396 32,238 1,271,567 - -1,271,567-LF 183 Open Yes 2,527 2,199 4,439 175,640 - - 175,640 -LF 184 Open Yes 4,705 1,505 2,888 335,901 - 159,452174,426 2,024A-10**Industry-Supplied Data for Methane Oxidation Analys is** **Fac_ID Open_flag** **GCS_flag G_CH4** **(MT) R** **(MT) R/CE/f_Rec** **(MT) Total** **Area********waste (m** **2 )** **Area1 (organic)** **(m 2** **) Area2** **(Clay) (m** **2 )** **Area3 (Sand)** **(m 2** **) Area4** **(other) (m** **2 )** LF 185 Open Yes 20,340 5,908 14,607 520,849 - 520,849 - -LF 186 Closed Yes 14,666 14,964 18,783 801,306 - -- 801,306LF 187 Open Yes 3,747 5,100 9,432 338,329 - 338,329- -LF 188 Open Yes 13,855 6,613 8,237 417,246 - 417,246 - -LF 189 Open Yes 5,895 7,255 9,622 178,068 - - 178,068 -LF 190 Open Yes 26,091 36,576 73,058 758,813 - 758,813 - -LF 191 Open No 4,860 - - 204,778 - - - 204,778LF 192 Open Yes 35,586 30,603 44,219 1,311,228a- 623,238 - 404,700LF 193 Open Yes 14,146 10,358 13,415 424,126 - 387,703 36,423 -LF 194 Open Yes 28,337 20,551 23,848 735,340 - 735,340 - -LF 195 Open Yes 12,588 9,202 11,515 375,966 - 357,755 18,212 -LF 196 Closed Yes 3,786 3,227 3,397 210,444 - - - 210,444LF 197 Open Yes 15,057 17,988 25,146 410,771 - 386,084 - 24,687LF 198 Open Yes 50,173 34,003 40,421 1,157,442 - 1,157,442- -LF 199 Open Yes 22,618 10,851 17,162 343,995 - - -343,995LF 200 Closed Yes 8,919 4,045 6,047 420,888 - - - 420,888LF 201 Open Yes 72,562 36,697 46,100 1,225,027 - 930,001 295,026 -LF 202 Open Yes 27,332 1,862 3,112 821,541a- 813,447 - -LF 203 Open Yes 19,865 9,962 13,348 586,410 - 543,512 - 42,898LF 204 Closed Yes 9,335 5,459 6,089 857,964 - - - 857,964LF 205 Closed Yes 626 2,670 3,579 222,585 - - - 222,585LF 206 Closed Yes 7,232 1,962 2,559 590,862 - - - 590,862LF 207 Open Yes 86,634 32,322 36,758 1,507,508 - 1,446,803- 60,705A-11**Industry-Supplied Data for Methane Oxidation Analys is** **Fac_ID Open_flag** **GCS_flag G_CH4** **(MT) R** **(MT) R/CE/f_Rec** **(MT) Total** **Area********waste (m** **2 )** **Area1 (organic)** **(m 2** **) Area2** **(Clay) (m** **2 )** **Area3 (Sand)** **(m 2** **) Area4** **(other) (m** **2 )** LF 208 Open Yes 41,550 16,637 20,498 1,473,108a- 586,815 - 857,964LF 209 Open Yes 30,860 15,711 20,392 598,956 - 97,128 501,828 -LF 210 Open Yes 17,792 10,354 14,919 414,008 - 414,008 - -LF 211 Closed Yes 45,117 20,120 26,951 679,896 - -- 679,896LF 212 Open Yes 16,969 15,955 21,878 581,554 - - -581,554LF 213 Open No 8,042 - - 521,658 - - - 521,658LF 214 Open Yes 6,941 4,701 11,173 348,042 - 323,760 - 24,282LF 215 Open Yes 46,620 30,268 39,761 960,353 - 960,353 - -LF 216 Closed No 1,415 - - 137,598 - - - 137,598LF 217 Open Yes 12,851 5,041 7,613 226,632 - - - 226,632LF 218 Open Yes 16,888 6,075 9,467 433,029 - 433,029 - -LF 219 Open Yes 38,682 27,331 38,199 1,090,667 - -- 1,090,667LF 220 Open Yes 9,762 3,024 4,934 371,515a- - - 307,167LF 221 Open Yes 13,654 13,508 18,949 481,593 - 453,264 - 28,329LF 222 Open Yes 12,109 8,136 9,852 553,630 - 108,460 445,170 -LF 223 Open Yes 6,047 2,781 3,403 198,303 - 168,760- 29,543LF 224 Open Yes 20,843 8,763 13,030 282,481 - - - 282,481LF 225 Closed Yes 4,083 3,080 3,320 283,290 - 283,290 - -LF 226 Closed Yes 12,484 9,694 10,288 675,849 - - -675,849LF 227 Open Yes 27,042 16,922 19,126 578,721 - 578,721 - -LF 228 Open Yes 3,392 1,510 2,801 222,585 - 214,491- 8,094LF 229 Open No 1,413 - - 188,590 - - 188,590 -LF 230 Open Yes 21,027 12,863 16,715 724,413a- 724,413 - 20,235A-12**Industry-Supplied Data for Methane Oxidation Analys is** **Fac_ID Open_flag** **GCS_flag G_CH4** **(MT) R** **(MT) R/CE/f_Rec** **(MT) Total** **Area********waste (m** **2 )** **Area1 (organic)** **(m 2** **) Area2** **(Clay) (m** **2 )** **Area3 (Sand)** **(m 2** **) Area4** **(other) (m** **2 )** LF 231 Open Yes 4,771 6,038 8,380 186,971 - 154,59532,376 -LF 232 Open Yes 14,297 10,676 14,355 295,431 - 295,431 - -LF 233 Open Yes 14,113 6,111 8,770 328,616 - 296,240 32,376 -LF 234 Closed Yes 7,753 5,518 5,817 445,170 - - - 445,170LF 235 Open Yes 15,755 13,135 16,617 607,050 - 607,050 - -LF 236 Open Yes 24,038 22,020 29,639 895,738 - - -895,738LF 237 Open Yes 7,125 10,424 12,712 389,080 - - - 389,080LF 238 Open Yes 7,799 9,837 11,851 413,526 - - - 413,526LF 239 Open Yes 14,307 15,585 18,593 433,029 - 218,538 - 214,491LF 240 Open Yes 24,096 28,784 37,009 918,669 - 279,243 - 639,426LF 241 Closed Yes 2,647 2,497 3,109 437,076 - - - 437,076LF 242 Closed Yes 5,128 4,826 5,471 291,384 - - 174,021 117,363LF 243 Open Yes 1,381 927 1,941 343,995 - - - 343,995LF 244 Closed Yes 2,993 1,441 1,524 582,768 - 582,768 - -LF 245 Open Yes 4,496 518 657 503,852 - 503,852 - -LF 246 Open Yes 1,424 2,054 3,101 279,243 - 279,243- -LF 247 Open Yes 19,844 35,904 46,717 1,193,865 - -- 1,193,865LF 248 Open Yes 4,353 868 1,008 509,922 - 303,525 -206,397LF 249 Open Yes 2,393 442 2,447 159,452 - - - 159,452LF 250 Open Yes 3,579 2,413 4,150 1,185,771 1,040,079- - 145,692LF 251 Closed Yes 588 1,122 1,191 376,371 - 376,371- -LF 252 Open Yes 22,933 22,399 25,696 708,225 24,282234,726 - 449,217LF 253 Open No 1,127 - - 161,880 - 161,880 - -A-13**Industry-Supplied Data for Methane Oxidation Analys is** **Fac_ID Open_flag** **GCS_flag G_CH4** **(MT) R** **(MT) R/CE/f_Rec** **(MT) Total** **Area********waste (m** **2 )** **Area1 (organic)** **(m 2** **) Area2** **(Clay) (m** **2 )** **Area3 (Sand)** **(m 2** **) Area4** **(other) (m** **2 )** LF 254 Open No 3,686 - - 194,256 - - - 194,256LF 255 Open Yes 4,920 2,821 3,572 356,136 - - - 356,136LF 256 Open Yes 4,469 6,926 14,315 501,828 - - - 501,828LF 257 Open Yes 1,061 806 1,326 133,551 - 133,551 --LF 258 Open No 1,710 - - 178,068 - - - 178,068LF 259 Open Yes 2,657 1,792 4,106 222,585 - - - 222,585LF 260 Open Yes 3,978 2,820 4,635 396,606 - - - 396,606LF 261 Open Yes 17,131 7,528 10,864 768,930 - 768,930 - -LF 262 Closed No 2,249 - - 571,988a309,989 - - -aThe total area of waste for did not equal the sum of the soil-specific areas. Used the sum of the soil-specific areas rather than thisreported value when calculating the area-weighted oxidation fractions.