1 

Date: December 12, 2012

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 (SWICS) Methane Oxidation Addendum 2012, 

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

representatives. 

Background 

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

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

relative amount of methane removed from the landfill 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 flux, through the soil surface (higher 

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

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

aerobic soil layer, which leads to more oxidation),

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

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

activity. 

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

and operators of municipal solid waste (MSW) landfills 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 published literature. Consequently, MSW 

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

industry representatives compiled data from published studies and evaluated soil oxidation 

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

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

HH. This memorandum summarizes these options, provides 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 selecting a specific option for inclusion in 

Subpart HH to replace the current 10 percent default 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 current 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 all landfills based on 

published literature included in the Addendum (SWICS, 2012). The median 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 soil cover type. For 

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

average oxidation fractions for different soil types presented in the SWICS Addendum 

are summarized in Table 1. 

Table 1. Median and Arithmetic Average Methane Oxidation Fractions (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 soil cover type. This 

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

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

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

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

divided by the methane flux rate. Based on the summary data 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/m2/d) 

Organic Cover 4.0 

Clay Cover 7.6 

Sand Cover 5.2 

Other Mixtures 5.8 

Note: g/m2/d = grams per square meter per day 

• Option 4. Use a binned approach where the average oxidation fraction is determined for 

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

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

landfills/columns with low methane flux rates (less than 10 g/m2/d), a second oxidation 

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

flux rates (10 to 70 g/m2/d), and a third oxidation fraction was determined using study 

data for landfills/columns with high methane flux rates (greater than 70 g/m2/d). The 

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

Table 3 summarizes these values along with the corresponding central tendency value 

used in the analysis of the industry-supplied data. 

Figure 1. Methane oxidation percent as a function of methane emissions. 

Mean values are shown with standard error and median values 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/m2/d 0.384 0.335 0.35 

Bin 2: Flux of 10-70 

g/m2/d 

0.274 0.210 0.25 

Bin 3: Flux >70 g/m2/d 0.124 0.077 0.10 

Note: g/m2/d = grams per square meter per day

Implications of These Options to Subpart HH 

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

would be simple to adopt. However, as described in the Background, 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 determine an area-weighted oxidation fraction, 

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

Subpart HH. However, this method does not account for differences 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 landfill with the gas collection system would 

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

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

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

fractions, the other oxidation fractions do not appear to vary 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 fractions 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 oxidation 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 variability and uncertainty in the default 

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

column studies for sand covers was 10 g/m2/d, while the mean methane oxidation rate for field 

studies of sand covers was only 0.30 g/m2/d, leading to an arithmetic mean of 5.2 g/m2/d. 

Additionally, the default methane oxidation rate for clay 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 rate 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 rate and percent oxidation as a 

function of methane loading to the landfill cover (Figure 2 from 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 appropriate binned methane oxidation fraction to 

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

landfill is established with no other soil type considerations. 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 considering 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 fraction 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 oxidation fraction. The binned approach 
6 

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

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

rates are expected to temporally decline. 

Industry-Provided Data Analysis and Results 

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

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

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

determined by Equation HH-1, the annual methane recovery determined 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 reporting 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 open landfills (208 of 262 landfills, or 80 

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

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

memorandum. 

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

landfill with a gas collection system using the reported methane recovery rates and backcalculated methane generation rates [i.e., R/(CE×fRec)]. For landfills with gas collection systems, 

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

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

equation (HH-6 versus HH-8) the facility would use in reporting 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 generation determined by Equation HH-1, or 

(2) the back-calculated methane generation rate [i.e., R/(CE×fRec)] was less than the methane 

generation determined by Equation HH-1. Equation HH-6 was assumed 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×fRec) –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, fRec = fraction of 

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

containing waste (m2). For facilities where Equation HH-6 was assumed to be used, the methane 

flux was calculated as (GCH4 –R)/SA, where GCH4 = annual methane generation determined 

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

methane flux was calculated as GCH4/SA . The flux rates were then converted to the appropriate 

units (g/m2/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 methane 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 Addendum was used for Option 31; and 

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

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

“after” situations. 

Table 4. Cumulative Methane Emissions Calculated Using Different Options for 

Estimating Methane Oxidation 

Option 

Cumulative CH4 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 emissions than Option 1 because 79 percent of 

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

generation, clay and “other mixture” soil covers represented 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 types reported by the landfills in the 

industry-supplied dataset. 

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

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

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

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

A large portion of the landfills in the dataset have methane 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 fractions by soil type and the single 

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

presence of a landfill gas collection system. Although there 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 collection systems. The only landfill without a 

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

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

time, can have higher oxidation fractions as the methane 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 since 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 GCS1

Number of 

Landfills in 

Bin With GCS1

Cumulative 

Number of 

Landfills in 

Bin 

Bin 1: Flux <10 g/m2/d (OX=0.35) 1 78 79 

Bin 2: Flux of 10-70 g/m2/d (OX=0.25) 31 142 173 

Bin 3: Flux >70 g/m2/d (OX=0.10) 9 1 10 

1

 GCS = Gas collection system 

Conclusions/Recommendations 

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

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

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

These data suggest that the current default oxidation fraction 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 under Subpart HH. 

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

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

oxidation fraction than soil type. Furthermore, a significant 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 collection 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 rate by soil type (Option 3) is not 

recommended for use in Subpart HH. 

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

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

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

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

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

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

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

for close landfills). As such, the binned” approach (Option 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 State-of-thePractice on LFG Collection Efficiency, Methane Oxidation, and Carbon Sequestration in 

Landfills.” Prepared for Solid Waste Industry for Climate 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 Data Supplied by 

Industry Representatives for Evaluation of Methane Oxidation Alternatives 

 
A-2 

Industry-Supplied Data for Methane Oxidation Analysis 

Fac_ID Open_flag GCS_flag 

G_CH4 

(MT) 

R 

(MT) 

R/CE/f_Rec

(MT) 

Total Areawaste 

(m2) 

Area1 

(organic) 

(m2) 

Area2 

(Clay) 

(m2) 

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 LF 004 Open Yes 8,759 16,503 20,111 433,838 - 173,616 LF 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 - - LF 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 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 - - LF 012 Closed Yes 574 1,062 2,249 206,397 - - LF 013 Open Yes 14,237 6,895 8,568 278,029 191,018 87,011 LF 014 Open Yes 13,813 7,541 9,031 305,549 162,285 143,264 LF 015 Open Yes 18,541 13,646 15,588 573,460 203,564 369,896 LF 016 Open Yes 15,634 9,252 10,713 554,439 196,280 358,160 LF 017 Open Yes 4,537 2,726 3,992 158,238 - - LF 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 LF 020 Closed Yes 2,523 3,320 3,720 277,220 - 119,387 LF 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 LF 023 Open Yes 11,332 6,467 11,102 458,930 - 257,794 
A-3 

Industry-Supplied Data for Methane Oxidation Analysis 

Fac_ID Open_flag GCS_flag 

G_CH4 

(MT) 

R 

(MT) 

R/CE/f_Rec

(MT) 

Total Areawaste 

(m2) 

Area1 

(organic) 

(m2) 

Area2 

(Clay) 

(m2) 

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 LF 027 Open Yes 28,731 13,227 21,535 708,225a - - LF 028 Open Yes 7,588 3,876 8,375 214,896 - 206,802 LF 029 Open No 2,460 - - 84,178 - 80,131 LF 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 LF 032 Open Yes 11,605 9,151 10,827 570,222 - 471,476 LF 033 Open Yes 6,559 3,810 5,423 297,455 - 285,314 LF 034 Closed No 1,642 - - 198,303 - - LF 035 Open Yes 16,683 8,638 10,888 373,133 243,225 129,909 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 - - LF 040 Open No 2,222 - - 133,551 - 78,512 LF 041 Open Yes 12,374 6,492 11,163 548,369a - - LF 042 Open Yes 14,679 10,679 13,117 691,228 350,875 12,141 LF 043 Open Yes 48,974 8,202 11,736 2,760,054 - 2,751,960 LF 044 Open No 5,252 - - 370,301 - - LF 045 Open No 4,678 - - 301,906 - - LF 046 Open Yes 9,235 7,757 14,220 410,771 - 410,771 
A-4 

Industry-Supplied Data for Methane Oxidation Analysis 

Fac_ID Open_flag GCS_flag 

G_CH4 

(MT) 

R 

(MT) 

R/CE/f_Rec

(MT) 

Total Areawaste 

(m2) 

Area1 

(organic) 

(m2) 

Area2 

(Clay) 

(m2) 

LF 047 Closed Yes 2,514 1,695 2,260 242,820 - - LF 048 Open Yes 16,939 12,571 17,105 482,807 - 478,760 LF 049 Open Yes 41,360 22,242 26,887 701,750 - 393,368 LF 050 Closed Yes 12,699 8,635 10,358 445,170 - - LF 051 Open Yes 8,908 5,707 7,484 336,306 - 328,212 LF 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 LF 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 - 60,705 LF 059 Open No 4,076 - - 202,350 - 174,021 LF 060 Open Yes 15,095 10,270 12,436 335,092 95,509 94,700 LF 061 Open Yes 14,256 12,612 14,404 303,525 36,423 61,110 LF 062 Open Yes 8,575 7,144 7,946 218,538 52,611 37,232 LF 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 LF 066 Open Yes 7,635 8,817 11,518 333,068 - 300,692 LF 067 Open Yes 1,547 187 752 146,501a - - 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 Analysis 

Fac_ID Open_flag GCS_flag 

G_CH4 

(MT) 

R 

(MT) 

R/CE/f_Rec

(MT) 

Total Areawaste 

(m2) 

Area1 

(organic) 

(m2) 

Area2 

(Clay) 

(m2) 

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 - - LF 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 - - LF 083 Open Yes 3,377 4,626 6,014 176,449 - 52,611 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 - - LF 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 LF 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 
A-6 

Industry-Supplied Data for Methane Oxidation Analysis 

Fac_ID Open_flag GCS_flag 

G_CH4 

(MT) 

R 

(MT) 

R/CE/f_Rec

(MT) 

Total Areawaste 

(m2) 

Area1 

(organic) 

(m2) 

Area2 

(Clay) 

(m2) 

LF 093 Open Yes 11,698 2,472 3,522 415,222 - 138,003 LF 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 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 - - LF 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 LF 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 LF 107 Open Yes 43,173 29,001 39,297 788,356a 40,470 - LF 108 Open Yes 52,884 13,807 19,487 1,033,604a - 128,695 LF 109 Closed Yes 6,567 2,187 2,325 416,841 - - LF 110 Closed Yes 2,992 1,010 1,362 999,609 - - LF 111 Closed No 1,935 - - 161,880 - - LF 112 Closed No 1,565 - - 445,170 - - LF 113 Closed Yes 2,108 621 938 323,760 - - LF 114 Closed Yes 1,295 219 360 335,901 - - LF 115 Closed Yes 2,940 3,952 5,288 364,230 - - 
A-7 

Industry-Supplied Data for Methane Oxidation Analysis 

Fac_ID Open_flag GCS_flag 

G_CH4 

(MT) 

R 

(MT) 

R/CE/f_Rec

(MT) 

Total Areawaste 

(m2) 

Area1 

(organic) 

(m2) 

Area2 

(Clay) 

(m2) 

LF 116 Closed Yes 8,729 1,954 2,606 611,097 - - LF 117 Closed Yes 2,706 689 866 295,431 - - LF 118 Open No 4,054 - - 793,212 - - LF 119 Open Yes 16,040 13,757 21,539 900,458 3,642 896,815 LF 120 Open Yes 23,184 14,943 18,508 342,781 - 334,687 LF 121 Open No 2,309 - - 152,572 - - LF 122 Open Yes 13,346 5,989 8,096 539,465 - - 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 - 352,089 LF 127 Closed No 1,445 - - 117,363 - - LF 128 Closed No 1,492 - - 178,068 - - LF 129 Closed Yes 1,115 2,161 2,366 311,619 - - LF 130 Closed No 1,196 - - 226,632 - - LF 131 Closed Yes 2,252 935 1,311 315,666 - - LF 132 Closed Yes 2,663 1,804 2,596 178,068 - - LF 133 Closed Yes 2,135 1,171 2,455 445,170 - - LF 134 Closed Yes 1,317 826 1,152 343,995 - - LF 135 Open Yes 2,339 1,168 2,570 177,259 - 176,045 LF 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 - - LF 138 Open Yes 16,534 14,375 20,303 453,264 241,201 38,042 
A-8 

Industry-Supplied Data for Methane Oxidation Analysis 

Fac_ID Open_flag GCS_flag 

G_CH4 

(MT) 

R 

(MT) 

R/CE/f_Rec

(MT) 

Total Areawaste 

(m2) 

Area1 

(organic) 

(m2) 

Area2 

(Clay) 

(m2) 

LF 139 Open Yes 1,465 970 1,669 91,462a - - LF 140 Open Yes 6,024 3,998 5,766 418,865 - 315,666 LF 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 LF 143 Closed Yes 5,334 1,616 1,728 205,992 - - LF 144 Open Yes 2,830 1,246 1,639 134,765 - 122,624 LF 145 Open Yes 4,957 2,480 3,123 242,820 26,306 - LF 146 Open No 1,801 - - 212,872 - - LF 147 Closed Yes 3,184 2,528 3,284 404,700 - - LF 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 LF 150 Open Yes 12,080 10,832 14,074 449,217 - 169,974 LF 151 Closed Yes 12,321 19,620 26,950 1,165,536 - - LF 152 Closed Yes 11,236 10,251 10,790 416,841 - - LF 153 Open Yes 30,321 20,238 26,082 748,695 - 157,833 LF 154 Open Yes 6,385 2,317 3,413 481,188 - - LF 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 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 LF 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 
A-9 

Industry-Supplied Data for Methane Oxidation Analysis 

Fac_ID Open_flag GCS_flag 

G_CH4 

(MT) 

R 

(MT) 

R/CE/f_Rec

(MT) 

Total Areawaste 

(m2) 

Area1 

(organic) 

(m2) 

Area2 

(Clay) 

(m2) 

LF 162 Closed Yes 7,193 5,070 5,385 263,055 - - LF 163 Open Yes 7,266 5,418 9,168 367,063 - - LF 164 Open Yes 17,876 9,850 12,952 497,376 - 174,021 LF 165 Open Yes 6,134 2,713 6,049 222,180 - 197,898 LF 166 Closed Yes 26,933 13,352 14,112 526,110 - - LF 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 - LF 169 Closed Yes 4,010 646 780 283,290 - - LF 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 LF 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 LF 175 Open Yes 20,829 10,098 19,160 651,567 - 103,603 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 - - LF 179 Open Yes 37,137 12,117 15,638 586,410 - - LF 180 Closed Yes 7,934 3,232 3,503 651,567 - 441,123 LF 181 Closed Yes 3,916 3,150 3,330 343,995 - - LF 182 Open Yes 62,216 25,396 32,238 1,271,567 - - LF 183 Open Yes 2,527 2,199 4,439 175,640 - - LF 184 Open Yes 4,705 1,505 2,888 335,901 - 159,452 
A-10 

Industry-Supplied Data for Methane Oxidation Analysis 

Fac_ID Open_flag GCS_flag 

G_CH4 

(MT) 

R 

(MT) 

R/CE/f_Rec

(MT) 

Total Areawaste 

(m2) 

Area1 

(organic) 

(m2) 

Area2 

(Clay) 

(m2) 

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 - - LF 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 - - LF 190 Open Yes 26,091 36,576 73,058 758,813 - 758,813 LF 191 Open No 4,860 - - 204,778 - - LF 192 Open Yes 35,586 30,603 44,219 1,311,228a - 623,238 LF 193 Open Yes 14,146 10,358 13,415 424,126 - 387,703 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 LF 196 Closed Yes 3,786 3,227 3,397 210,444 - - LF 197 Open Yes 15,057 17,988 25,146 410,771 - 386,084 LF 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 - - LF 200 Closed Yes 8,919 4,045 6,047 420,888 - - LF 201 Open Yes 72,562 36,697 46,100 1,225,027 - 930,001 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 LF 204 Closed Yes 9,335 5,459 6,089 857,964 - - LF 205 Closed Yes 626 2,670 3,579 222,585 - - LF 206 Closed Yes 7,232 1,962 2,559 590,862 - - LF 207 Open Yes 86,634 32,322 36,758 1,507,508 - 1,446,803 
A-11 

Industry-Supplied Data for Methane Oxidation Analysis 

Fac_ID Open_flag GCS_flag 

G_CH4 

(MT) 

R 

(MT) 

R/CE/f_Rec

(MT) 

Total Areawaste 

(m2) 

Area1 

(organic) 

(m2) 

Area2 

(Clay) 

(m2) 

LF 208 Open Yes 41,550 16,637 20,498 1,473,108a - 586,815 LF 209 Open Yes 30,860 15,711 20,392 598,956 - 97,128 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 - - LF 212 Open Yes 16,969 15,955 21,878 581,554 - - LF 213 Open No 8,042 - - 521,658 - - LF 214 Open Yes 6,941 4,701 11,173 348,042 - 323,760 LF 215 Open Yes 46,620 30,268 39,761 960,353 - 960,353 LF 216 Closed No 1,415 - - 137,598 - - LF 217 Open Yes 12,851 5,041 7,613 226,632 - - LF 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 - - LF 220 Open Yes 9,762 3,024 4,934 371,515a - - LF 221 Open Yes 13,654 13,508 18,949 481,593 - 453,264 LF 222 Open Yes 12,109 8,136 9,852 553,630 - 108,460 LF 223 Open Yes 6,047 2,781 3,403 198,303 - 168,760 LF 224 Open Yes 20,843 8,763 13,030 282,481 - - LF 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 - - LF 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 LF 229 Open No 1,413 - - 188,590 - - LF 230 Open Yes 21,027 12,863 16,715 724,413a - 724,413 
A-12 

Industry-Supplied Data for Methane Oxidation Analysis 

Fac_ID Open_flag GCS_flag 

G_CH4 

(MT) 

R 

(MT) 

R/CE/f_Rec

(MT) 

Total Areawaste 

(m2) 

Area1 

(organic) 

(m2) 

Area2 

(Clay) 

(m2) 

LF 231 Open Yes 4,771 6,038 8,380 186,971 - 154,595 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 LF 234 Closed Yes 7,753 5,518 5,817 445,170 - - LF 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 - - LF 237 Open Yes 7,125 10,424 12,712 389,080 - - LF 238 Open Yes 7,799 9,837 11,851 413,526 - - LF 239 Open Yes 14,307 15,585 18,593 433,029 - 218,538 LF 240 Open Yes 24,096 28,784 37,009 918,669 - 279,243 LF 241 Closed Yes 2,647 2,497 3,109 437,076 - - LF 242 Closed Yes 5,128 4,826 5,471 291,384 - - LF 243 Open Yes 1,381 927 1,941 343,995 - - LF 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 - - LF 248 Open Yes 4,353 868 1,008 509,922 - 303,525 LF 249 Open Yes 2,393 442 2,447 159,452 - - LF 250 Open Yes 3,579 2,413 4,150 1,185,771 1,040,079 - LF 251 Closed Yes 588 1,122 1,191 376,371 - 376,371 LF 252 Open Yes 22,933 22,399 25,696 708,225 24,282 234,726 LF 253 Open No 1,127 - - 161,880 - 161,880 
A-13 

Industry-Supplied Data for Methane Oxidation Analysis 

Fac_ID Open_flag GCS_flag 

G_CH4 

(MT) 

R 

(MT) 

R/CE/f_Rec

(MT) 

Total Areawaste 

(m2) 

Area1 

(organic) 

(m2) 

Area2 

(Clay) 

(m2) 

LF 254 Open No 3,686 - - 194,256 - - LF 255 Open Yes 4,920 2,821 3,572 356,136 - - LF 256 Open Yes 4,469 6,926 14,315 501,828 - - LF 257 Open Yes 1,061 806 1,326 133,551 - 133,551 LF 258 Open No 1,710 - - 178,068 - - LF 259 Open Yes 2,657 1,792 4,106 222,585 - - LF 260 Open Yes 3,978 2,820 4,635 396,606 - - LF 261 Open Yes 17,131 7,528 10,864 768,930 - 768,930 LF 262 Closed No 2,249 - - 571,988a 309,989 - 

a The total area of waste for did not equal the sum of the soil-specific areas. Used the sum of the soil-specific a

reported value when calculating the area-weighted oxidation fractions.