Page 1 of 39
**Subpart HH —**  **Municipal Solid Waste Landfills**

(a) This source category applies to municipal solid waste (MSW) landfills that accepted waste on or after January 1, 1980. § 98.340 Definition of the source category.

(b) This source category does not include Resource Conservation and Recovery Act (RCRA) Subtitle C or Toxic Substances Control Act (TSCA) hazardous waste landfills, construction and demolition waste landfills, or industrial waste lan dfills. (c) This source category consists of the following sources at municipal solid waste (MSW) landfills: Landfills, landfill gas collection systems, and landfill gas destruction devices (including flares).

You must report GHG emissions under this subpart if your facility contains a MSW landfill and the facility meets the requirements of §98.2(a)(1). § 98.341 Reporting threshold.

(a) You must report CH § 98.342 GHGs to report.

4 generation and CH 4

(b) You must report CH emissions from landfills.

4

(c) You must report under subpart C of this part (General Stationary Fuel Combustion Sources) the emissions of CO destruct ion resulting from landfill gas collection and combustion systems.

2 , CH 4 ,Page 2 of 39

and N 2 O from each stationary combustion unit following the requireme nts of subpart C.

(a) For all landfills subject to the reporting requirements of this subpart, calculate annual modeled CH § 98.343 Calculating GHG emissions.

4 generation

(1) Calculate annual modeled CH according to the applicable requirements in paragraphs (a)(1) through (a)(3) of this section.

4 generation using Equation
HH

– 1 of this section.

Where:

G CH4 = Modeled methane generation rate in reporting year T (metric tons CH 4
x = Year in which waste was disposed. ).

S = Start year of calculation. Use th e year 1960 or the opening year of the landfill, whichever is more recent. T = Reporting year for which emissions are calculated. W X

MCF = Methane correction factor (fraction). Use the default value of 1 unless there is active aeration of waste within the landfill during the reporting year. If there is active aeration of waste within the landfill during the reporting year, use either the default value of 1 or select an alternative value no = Quantity of waste disposed in the landfill in year × from measurement data, tipping fee receipts, or other company records (metric tons, as received (wet weight)).Page 3 of 39
less than 0.5 based on site

- specific aeration parameters. DOC = Degradable organic carbon from Table HH

– 1 of this subpart or measurement data, if availa ble [fraction (metric tons C/metric ton waste)]. DOC F

F = Fraction by volume of CH = Fraction of DOC dissimilated (fraction). Use the default value of 0.5.

4

k = Rate constant from Table HH

– 1 to this subpart (yr in landfill gas from measurement data on a dry basis, for the current reporting year , if available (fraction ); , dry basis, corrected to 0 percent oxygen ); otherwise, use the default is of 0.5.

−1

(2) For years when material

- specific waste quantity data are available, apply Equation HH

– 1 of this section for each waste quantity type and sum the CH ). Select the most applicable k value for the majority of the past 10 years (or operating life, whichever i s shorter).

4 generation rates for all waste types to calculate the total modeled CH 4 generation rate for the landfill. Use the appropriate parameter values for k, DOC, MCF, DOC F , and F shown in Table HH

– 1 of this subpart. The annual quantity of each type of waste disposed must be calculated as the sum of the daily quantities of waste (of that type) disposed. You may use the bulk waste parameters for a portion of your waste materials when using the material

- specific modeling approach for mixed waste streams that cannot be designated to a specific material type. For years when waste composition data ar e not available, use the bulk waste parameterPage 4 of 39
values for k and DOC in Table HH

– 1 to this subpart for the total quantity of waste disposed in those years. (3) Beginning in the first emissions reporting year and for each year thereafter, if scales are in pla ce, you must determine the annual quantity of waste (in metric tons as received, i.e., wet weight) disposed of in the landfill using paragraph (a)(3)(i) of this section for all containers and for all vehicles used to haul waste to the landfill, except for passenger cars, light duty pickup trucks, or waste loads that cannot be measured using the scales due to physical limitations (load cannot physically access or fit on the scale) and/or operational limitations of the scale (load exceeding the limits

or sens itivity range of the scale). If scales are not in place, you must use paragraph (a)(3)(ii) of this section to determine the annual quantity of waste disposed. For waste hauled to the landfill in passenger cars or light duty pickup trucks, you may use eithe r paragraph (a)(3)(i) or paragraph (a)(3)(ii) of this section to determine the annual quantity of waste disposed. For loads that cannot be measured using the scales due to physical and/or operational limitations of the scale, you must use paragraph (a)(3)( ii) of this section or similar engineering calculations to determine the annual quantity of waste disposed. The approach used to determine the annual quantity of waste disposed of must be documented in the monitoring plan.Page 5 of 39
(i) Use direct mass measurements of each individual load received at the landfill using either of the following methods: (A) Weigh using mass scales each vehicle or container used to haul waste as it enters the landfill or disposal area; weigh using mass scales each vehicle or container a fter it has off

loaded the waste; determine the quantity of waste received from the individual load as the difference in the two mass measurements; and determine the annual quantity of waste received as the sum of all waste loads received during the year. Alternatively, you may determine annual quantity of waste by summing the weights of all vehicles and containers entering the landfill and subtracting from it the sum of all the weights of vehicles and containers after they have off

- loaded the waste in the landfill. (B) Weigh using mass scales each vehicle or container used to haul waste as it enters the landfill or disposal area; determine a representative tare weight by vehicle or container type by weighing no less than 5 of each type of vehicle or contain er after it has off

- loaded the waste; determine the quantity of waste received from the individual load as the difference between the measured weight in and the tare weight determined for that container/vehicle type; and determine the annual quantity of wa ste received as the sum of all waste loads received during the year.Page 6 of 39 (ii) Determine the working capacity in units of mass for each type of container or vehicle used to haul waste to the landfill ( e.g.

(4) For years prior to the first emissions reporting year, use methods in paragraph (a)(3) of this section when waste disposal quantity data are readily available. When waste disposal quantity data are not readily available, W , using volumetric capacity and waste density

measuremen ts; direct measurement of a selected number of passenger vehicles and light duty pick

- up trucks; or similar methods); record the number of loads received at the landfill by vehicle/container type; calculate the annual mass per vehicle/container type as the mass product of the number of loads of that vehicle/container multiplied by its working capacity; and calculate the annual quantity of waste received as the sum of the annual mass per vehicle/container type across all of the vehicle/container types used t o haul waste to the landfill.

X shall be estimated using one of the applicable methods in paragraphs (a)(4)(i) through (a)(4)(iii) of this section. You must determine which method is most applicable to the conditions and disposal history of your facility. Historical waste disposal
quan tities should only be determined once, as part of the first annual report, and the same values should be used for allPage 7 of 39
subsequent annual reports, supplemented by the next year's data on new waste disposal. (i) Assume all prior years waste disposal quantitie s are the same as the waste quantity in the first year for which waste quantities are available. (ii) Use the estimated population served by the landfill in each year, the values for national average per capita waste disposal rates found in Table HH

– 2 to t his subpart, and calculate the waste quantity landfilled using Equation HH

– 2 of this section.

W here:

W X =
POP Quantity of waste placed in the landfill in year x (metric tons, wet basis).

X

WDR = Population served by the landfill in year x from city population , census data, or other estimates (capita).

X

(iii) Use a constant average waste disposal quantity calculated using Equation HH

– 3 of this section for each year the landfill was in operation (i.e., from the first year accepting waste until the last year for which waste disposal data is unavailable, inclusive). = Average per capita waste disposal rate for year x from Table HH

– 2 to this subpart (metric tons per capita per year, wet basis; tons/cap/yr).Page 8 of 39

Where :

W X
LFC = Landfill capacity or, for operating landfills, capacity of the landfill used (or the total quantity of waste

- in

- place) at the end of the year prior to the year when waste disposal data are available from design dra wings or engineering estimates (metric tons). = Quantity of waste placed in the landfill in year x (metric tons, wet basis).

YrData = Year in which the landfill last received waste or, for operating landfills, the year prior to the first reporting year when waste disposal data is first available from company records, or best availabl e data. YrOpen = Year in which the landfill first received waste from company records or best available data. If no data are available for estimating YrOpen for a closed landfill, use 30 years as the default operating life of the landfill.

(b) For landfills with gas collection systems, calculate the quantity of CH 4

(1) If you continuously monitor the flow rate, CH destroyed according to the requirements in paragraphs (b)(1) and (b)(2) of this section.

4 concentration , temperature, pressure, and, if necessary, moisture content of the landfill gas that is collected and routed to a destruction device (before any treatment equipment) using a monitoring meter specifically for CH 4 gas , as specified in §98.344, you must use this monitoring system and calculate the quantity of CH 4 recovered for destruction using Equation HH

– 4 of this section. A fully integrated system that directly reportsPage 9 of 39

CH 4 content requires no other calculation than summing the results of all monitoring per iods for a given year. 

## ( **) (**  **) (**  **) (**  **) (**  **)** 1,000 0.454 atm 1 P T R 520 0.0423 100% C V R N

1 n n

n n CH4 n 

## ∑

**= **  ** **  ** **  ** **  ** ×**  **× °**  **× ×**  **× ×**  **=** n MC K (Eq. HH

- 4)
W here:

R = Annual quantity of recovered CH 4 (metric tons CH 4 N = Total number of measurement periods in a year. Use daily averaging periods for a continuous monitoring system and N = 365 (or N = 366 for leap years). For weekly month ly sampling, as provided in paragraph (b)(2) of this section, use N= 52. 1 2. ).

n = Index for measurement period. (V) n = Cumulative volumetric flow for the measurement period in actual cubic feet (acf). If the flow rate meter automatically corrects for temperature and pressure, replace “520°R/(T) n × (P) n (K /1 atm” with “1”.

MC ) n = Moisture correction term for the measurement period, volumetric basis, as follows: (K MC ) n = 1 when (V) n and (C) n are both measured on a dry basis or if both are measured on a wet basis; (K MC ) n = [1

- (f H 2 O ) n ] when (V) n is measured on a wet basis and (C) n is measured on a dry basis; and (K MC ) n = 1/[1

- (f H2O ) n ] when (V) n is measured on a dry basis and (C) n (f is measured on a wet basis.

H 2 O ) n

(C = Average moisture c ontent of landfill gas during the measurement period, volumetric basis (cubic feet water per cubic feet landfill gas)

CH4 ) n = Average CH 4
0.0423 = Density of CH concentration of landfill gas for the measurement period (volume %).

4 Comment [A1]: Equation term C(CH4)N changed from (C)n.

lb/cf m at 520°R or 60 degrees Fahrenheit and 1 atm. Field Code ChangedPage 10 of 39
(T) n (P) = Average temperature at which flow is measured for the measurement period (°R).

n 0.454/1,000 = Conversion factor (metric t on/lb). = Average pressure at which flow is measured for the measurement period (atm).
(2) If you do not continuously monitor according to paragraph (b)(1) of this section, you must determine the flow rate, CH 4 concentration , temperature, pressure, and moisture content of the landfill gas that is collected and routed to a destruction device (before any treatment equipment) according to the requirements in paragraphs (b)(2)(i) through (b)(2)(iii) of this section and calculate the quantity of CH 4

(i) Continuously monitor gas flow rate and determine the cumulative volume of landfill gas each week month and the cumulative volume of landfill gas each year that is collected and routed to a destruction device (before any treatment equipment). Under this option, the gas flow meter i s not required to automatically correct for temperature, pressure, or, if necessary, moisture content. If the gas flow meter is not equipped with automatic correction for temperature, pressure, or, if necessary, moisture content, you must determine these
p arameters as specified in paragraph (b)(2)(iii) of this section. recovered for destruction using Equation HH

– 4 of this section.Page 11 of 39
(ii) Determine the CH 4

(iii) If the gas flow meter is not equipped with automatic correction for temperature, pressure, or, if necessary, moisture
content: concentration in the landfill gas that is collected and routed to a destruction device (before any treatment equipment) in a location near or representative of the loca tion of the gas flow meter at least once each calendar week month ; if only one measurement is made each calendar week month , there must be at least three fourteen days between
measurements.

(A) Determine the temperature and pressure in the landfill gas that is collected and routed to a destruction device (before any treatment equipment) in a location near or representative of the location of the gas flow meter at least once each calendar week month ; if only one measurement is made each calendar week month , there must be at least three fourteen days between
measurements. (B) If the CH 4 concentration is determined on a dry basis and fl ow is determined on a wet basis or CH 4 concentration is determined on a wet basis and flow is determined on a dry basis, and the flow meter does not automatically correct for moisture content, determine the moisture content in the landfill gas that is collected and routed to a destruction devic e (before any treatment equipment) in a location near or representative of thePage 12 of 39 location of the gas flow meter at least once each calendar week month ; if only one measurement is made each calendar week month , there must be at least three fourteen days between
measurements. (c) For all landfills, calculate CH 4 generation (adjusted for oxidation in cover materials) and actual CH 4 emissions (taking into account any CH 4

(1) Calculate CH recovery, and oxidation in cover materials) according to the applicable methods in paragraphs (c )(1) through (c)(3) of this section.

4 generation , adjusted for oxidation, from the modeled CH 4 (GCH 4 from Equation HH

– 1 of this section) using Equation HH

– 5 of this section.

Where:

MG = Methane generation, adjusted for oxidation, from the landfill in the reporting year (metric tons CH 4 G ).

CH4 = Modeled methane generation rate in reporting year from Equation HH

– 1 of this section (metric tons CH 4 OX = Oxidation fraction. Use the appropriate oxidation fraction default value from Table HH

- 4 of this subpart of 0.1 (10%)
. ).

(2) For landfills that do not have landfill gas collection systems, the CH 4 emissions are equal to the CH 4 generation (MG) calculated in Equation HH

– 5 of this section.Page 13 of 39 (3) For landfills with landfill gas collection systems, calculate CH 4

(i) Calculate CH emissions using the methodologies specified in paragraphs (c)(3)(i) and (c)(3)(ii) of this section.

4 emissions from the modeled CH 4 generation and measured CH 4 recovery using Equation HH

– 6 of this section.



## ( **)** 

# ( **) (**  **) {**  **} **  ** **  ** **  ** ×** 
**− ×**  **+**
**− ×**  ** **  ** **  ** ** 

**=** 

# ∑ **∑**

**− −**  N

n N

n 1 n Dest, n n 1 n CH4 f DE 1 R OX 1 R

- G Emissions (Eq. HH

- 6)

Where:
Emissions = Methane emissions from the landfill in the reporting year (metric tons CH 4 G ).

CH 4 = Modeled methane generation rate in reporting year from Equation HH

– 1 of this section or t he quantity of recovered CH 4 from Equation HH

– 4 of this section , whichever is greater (metric tons CH 4 N = Number of landfill gas measurement locations (assoc i ated w ith a destruction device or gas sent off

- site). If a single monitoring location is used to monitor volumetric flow and CH ).

4

R concentration of the recovered gas sent to one or multiple destruction devices, then N =1.

n = Quantity of recovered CH 4 from Equation HH

– 4 of this section for the n th

OX = Oxidation fraction. Use the appropriate oxidation fraction default value from Table HH

- 4 of this subpart of 0.1 (10%)
. measurement location (metric tons).

DE DE n = Destruction efficiency (lesser of manufacturer 's specified destruction efficiency and 0.99 ). ) for the n th measurement Field Code ChangedPage 14 of 39
location
. If the gas is transported off

- site for destruction, use DE = 1. If the volumetric flow and CH 4 concentration of the recovered gas is measured at a single location providing l andfill gas to multiple destruction devices (including some gas destroyed on

- site and some gas sent off

- site for destruction), calculate DE n

f as the arithmetic average of the DE values determined for each destruction device associated with that measurement location.

Dest , n = Fraction of hours the destruction device associated with the n th measurement location was operating ( during active gas flow calculated as the annual operating hours for the destruction device divided by the annual hours flow was sent to the destruction device as measured at the n th measurement location operating hours/8760 hours per year)
. If the gas is destroyed in a back

- up flare (or simlar sim i lar device) or if the gas is transported off

- site for destruction, use f Dest = 1. If the volumetric flow and CH 4 concentration of the recovered gas is measured at a single location providing landfill gas to multiple destruction devices (including some gas dest royed on

- site and some gas sent off

- site for destruction), calculate f Dest , n as the arithmetic average of the f Dest

(ii) Calculate CH values determined for each destruction device associated with that measurement location.

4 generation and CH 4 emissions us ing measured CH 4 recovery and estimated gas collection efficiency and Equations HH

– 7 and HH

– 8 of this section.



### OX)

- (1 f R CE

1 MG 1 n Rec,

n 

### × ** **  ** **  ** **  ** ** 

**=** 

# ∑

**=** N

n (Eq. HH

- 7) Field Code ChangedPage 15 of 39



### ( **)** 

## ( **) (**  **) {**  **} **  ** **  ** **  ** **  ** ×** 
**− ×**  **+**
**− ×**  ** **  ** **  ** **  ** ** 

**− **  ** **  ** **  ** **  ** **  ** **  ** **  ** **  ** **  ****

**=** 

## ∑ **∑ ∑** 

**= −**  **−** N

n N

n N

n 1 n Dest, n n 1 n 1 n Rec,

n f DE 1 R OX 1 R f R CE

1 Emissions (Eq. HH

- 8)

Where:

MG = Methane generation, adjusted for oxidation, from the landfill in the reporting year (metric tons CH 4 Emissions = Methane emissions from the landfill in the reporting year (metric tons CH ).

4 N = Number of landfill gas measurement locations (assoc i ated with a destruction device or gas sent off

- site). If a si ngle monitoring location is used to monitor volumetric flow and CH ).

4

R concentration of the recovered gas sent to one or multiple destruction devices, then N =1.

n = Quantity of recovered CH 4 from Equation HH

– 4 of this section for the n th measurement location (metric tons CH 4 CE = Collection efficiency estimated at landfill, taking into account system coverage, operation, and cover system materials from Table HH

– 3 of this subpart. If area by soil cover type information is not available, use default value of 0.75 (CE4 in table HH

– 3 of this subpart) for all areas under active influence of the collection system. ).

f Rec , n = Fraction of hours the recovery system associated with the n th

OX = O xidation fraction. Use appropriate oxidation fraction the oxidation fractions default value from Table HH

- 4 of this subpart of 0.1 (10%)
. measurement location was operating (annual operating hours/8 760 hours per year ) or annual operating hours / 8 78 4 per year for a leap year )
.

DE DE n = Destruction efficiency, (lesser of manufacturer's specified destruction Field Code ChangedPage 16 of 39 efficiency and 0.99 ). ) for the n th measurement location
. If the gas is transported off

- site for destruction, use DE = 1. If the volumetric flow and CH 4 concentration of the recovered gas is measured at a sing le location providing landfill gas to multiple destruction devices (including some gas destroyed on

- site and some gas sent off

- site for destruction), calculate DE n

f as the arithmetic average of the DE values determined for each destruction device associated with that measurement location.

Dest , n = Fraction of hours the destruction device associated with the n th measurement location was operating (device during active gas flow calculated as the annual operating hours for the destruction device divided by the annual hours flow was sent to the destruction device as measured at the n th measurement location. operating hours/8760 hours per year). If the gas is destroyed in a back

- up flare (or sim i lar device) or if the gas is transported off

- site for destruction, use f Dest = 1. If the volumetric flow and CH 4 concentration of the recovered gas is measured at a single location providing landfill gas to multiple destruction devices (including some gas d estroyed on

- site and some gas sent off

- site for destruction), calculate f Dest , n as the arithmetic average of the f Dest values determined for each destruction device associated with that measurement location.

(a) Mass measurement equipment used to determine the quantity of waste landfilled on or after January 1, 2010 must meet the requirements for weighing equipment as described in “Specifications, Tolerances, and Other Technical Requirements For Weighing and Measu ring Devices” NIST Handbook 44 (2009) (incorporated by reference, see §98.7). § 98.344 Monitoring and QA/QC requirements.Page 17 of 39 (b) For landfills with gas collection systems, operate, maintain, and calibrate a gas composition monitor capable of measuring the concentration of CH 4

(1) Method 18 at 40 CFR part 60, appendix A

– 6. in the recovered landfill gas using one of the methods specified in paragraphs (b)(1) through (b)(6) of this section or as specified by the manufacturer. Gas composition monitors shall be calibrated prior to the first reporting year and recalibrated either a nnually or at the minimum frequency specified by the manufacturer, whichever is more frequent, or whenever the error in the midrange calibration check exceeds ± 10 percent.

(2) ASTM D1945

– 03, Standard Test Met hod for Analysis of Natural Gas by Gas Chromatography (incorporated by reference,

see §98.7). (3) ASTM D1946

– 90 (Reapproved 2006), Standard Practice for Analysis of Reformed Gas by Gas Chromatography (incorporated by reference, see §98.7). (4) GPA Standard 2261

– 00, Analysis for Natural Gas and Similar Gaseous Mixtures by Gas Chromatography. (5) UOP539

– 97 Refinery Gas Analysis by Gas Chromatography (incorporated by reference, see §98.7). (6) As an alternative to the gas chromatography methods provided in paragraphs (b)(1) through (b)(5) of this section, you may use total gaseous organic concentration analyzers andPage 18 of 39 calculate the methane concentration following the requirements in paragraphs (b)(6)(i) through (b)(6)(iii) of this section. (i) Use Method 25A o r 25B at 40 CFR part 60, appendix A

– 7 to determine total gaseous organic concentration. You must calibrate the instrument with methane and determine the total gaseous organic concentration as carbon (or as methane; K=1 in Equation 25A

– 1 of Method 25A at 40 CFR part 60, appendix A

– 7). (ii) Determine a non

- methane organic carbon correction factor at the routine sampling location no less frequently than once a reporting year following the requirements in paragraphs (b)(6)(ii)(A) through (b)(6)(ii)(C) of this s ection. (A) Take a minimum of three grab samples of the landfill gas with a minimum of 20 minutes between samples and determine the methane composition of the landfill gas using one of the methods specified in paragraphs (b)(1) through (b)(5) of this secti on. (B) As soon as practical after each grab sample is collected and prior to the collection of a subsequent grab sample, determine the total gaseous organic concentration of the landfill gas using either Method 25A or 25B at 40 CFR part 60, appendix A

– 7 a s specified in paragraph (b)(6)(i) of this section. (C) Determine the arithmetic average methane concentration and the arithmetic average total gaseous organic concentrationPage 19 of 39 of the samples analyzed according to paragraphs (b)(6)(ii)(A) and (b)(6)(ii)(B) of this section, respectively, and calculate the non

- methane organic carbon correction factor as the ratio of the average methane concentration to the average total gaseous organic concentration. If the ratio exceeds 1, use 1 for the

non - methane organic carb on correction factor. (iii) Calculate the methane concentration as specified in Equation HH

– 9 of this section.

Where:

C CH4

f = Methane concentration in the landfill gas (volume %) for use in Equation HH

– 4 of this subpart.

NMOC

C = Non

- methane organic carbon correction factor from the most recent determination of the non

methane organic carbon correction factor as specified in paragraph (b)(6)(ii) of this section (unitless).

TGOC

(c) For landfills with gas collection systems, install, operate, maintain, and calibrate a gas flow meter capable of measuring the volumetric flow rate of the recovere d landfill gas using one of the methods specified in paragraphs (c)(1) through (c)(8) of this section or as specified by the manufacturer. Each gas flow meter shall be recalibrated either biennially (every 2 years) or at the minimum frequency specified by the = Total gaseous organic carbon concentration measured using Method 25A or 25B a t 40 CFR part 60, appendix A

– 7 during routine monitoring of the landfill gas (volume %).Page 20 of 39 manufacturer. Except as provided in §98.343(b)(2)(i), each gas flow meter must be capable of correcting for the temperature and pressure and, if necessary, moisture content. (1) ASME MFC

– 3M

– 2004, Measurement of Fluid Flow in Pipes Using Orifice, Nozzle , and Venturi (incorporated by reference,

see §98.7). (2) ASME MFC

– 4M

– 1986 (Reaffirmed 1997), Measurement of Gas Flow by Turbine Meters (incorporated by reference, see §98.7). (3) ASME MFC

– 6M

– 1998, Measurement of Fluid Flow in Pipes Using Vortex Flowmeters (incorporated by reference, see §98.7). (4) ASME MFC

– 7M

– 1987 (Reaffirmed 1992), Measurement of Gas Flow by Means of Critical Flow Venturi Nozzles (incorporated by reference, see §98.7). (5) ASME MFC

– 11M

– 2006 Measurement of Fluid Flow by Means of Coriolis Mass Flowmeters (incorporated by reference, see §98.7). The mass flow must be corrected to volumetric flow based on the measured temperature, pressure, and gas composition. (6) ASME MFC

– 14M

– 2003 Measurement of Fluid Flow Using Small Bore Precision Orifice Meters (incorporated by reference, see §98.7). (7) ASME MFC

– 18M

– 2001 Measurement of Fluid Flow using Variable Area Meters (incorporated by reference, see §98.7). (8) Method 2A or 2D at 40 CFR part 60, appendix A

– 1.Page 21 of 39 (d) All temperature, pressure, and if nec essary, moisture content monitors must be calibrated using the procedures and frequencies specified by the manufacturer. (e) The owner or operator shall document the procedures used to ensure the accuracy of the estimates of disposal quantities and, if app licable, gas flow rate, gas composition, temperature, pressure, and moisture content measurements. These procedures include, but are not limited to, calibration of weighing equipment, fuel flow meters, and other measurement devices. The estimated accuracy of measurements made with these devices shall also be recorded, and the technical basis for these estimates shall be provided. For landfills electing to measure the fraction by volume of CH 4

(1) Use a gas composition monitor capable of measuring the concentration of CH in landfill gas (F), follow the requirements in paragraphs ( e )(1) and ( e )(2) of this section.

4 on a dry basis that is properly operated, calibrated, and maintained according to the requirements specified in paragraph (b) of this section . You must either use a gas composition monitor that is also capable of measuring the
O 2 concentration correcting for excess (infiltration) air or you must operate, maintain, and calibrate a second monitor capable of measuring the O 2 concentration on a dry basis according to the manufacturer's specifications.Page 22 of 39 (2) Use Equation HH

- 10 of this section to correct the measured CH 4 concentration to 0% oxygen. If multiple CH 4 concentration measurements are made during the reporting year, determine F separately for each m easurement made during the reporting year, and use the results to determine the arithmetic average value of F for use in Equation HH

– 1 of this part. 

## ( **) **  ** **  ** **  ****

**− ×**  ** **  ** **  ** ** 

**=** 2 4 

### % 9

. 20 9

. 20 % 100 O C F c CH (Eq. HH

- 10 )

Where:

F = Fraction by volume of CH 4
C in landfill gas (fraction, dry basis, corrected to 0% oxygen).

CH4 = Measured CH 4
20.9 concentration in landfill gas (volume %, dry basis).

c = Defined O 2
20.9 = O correction basis, (volume %, dry basis).

2 %O concentration in air (volume %, dry basis).

2 = Measured O 2 (f ) The owner or operator shall document the procedures used to ensure the accuracy of the estimates of disposal quantities and, if applicable, gas flow rate, gas composition, temperature, pressure, and moisture content measurements. These procedures include, but are not limited to, calibration of weighing equipment, fuel flow meters, and other measurement devices. The estimated accuracy of measurements made with these Field Code Changed

concentration in landfill gas (volume %, dry basis).Page 23 of 39
devices shall also be recorded, and the technical bas is for these estimates shall be provided.

A complete record of all measured parameters used in the GHG emissions calculations is required. Therefore, whenever a quality

- assured value of a required parameter is unavailable (e.g., if a meter malfunctions during unit operation or if a required fuel sample is not taken), a substitute data value for the missing parameter shall be used in the calculations, according to the requirements in paragraphs (a) through (c ) of this section. § 98.345 Procedures for estimating missing data.

(a) For each missing value of the CH 4

(b) For missing gas flow rates, the substitute data value shall be the arithmetic average of the quality

- assured values of content , the substitute data value shall be the arithmetic average of the quality

- assured values of that parameter immediately preceding and immediately following the missing data incident. If the
“a fter” value is not obtained by the end of the reporting year, you may use the “before” value for the missing data substitution. If, for a particular parameter, no quality

- assured data are available prior to the missing data incident, the substitute data va lue shall be the first quality

- assured value obtained after the missing data period.Page 24 of 39 that parameter immediately preceding and immedia tely following the missing data incident. If the “after” value is not obtained by the end of the reporting year, you may use the “before” value for the missing data substitution. If, for a particular parameter, no quality

- assured data are available prior t o the missing data incident, the substitute data value shall be the first quality

- assured value obtained after the missing data period. (c) For missing daily waste disposal quantity data for disposal in the reporting years, year, the substitute value shall be the average daily waste disposal quantity for that day of the week as measured on the week before and week after the missing daily data.

In addition to the information required by §98.3(c), each annual report must contain the following information for each landfill. § 98.346 Data reporting requirements.

(a) A classification of the landfill as “open” (actively received waste in the reporting year) or “closed” (no longer receiving waste), the year in which the landfill first started accepting waste for di sposal, the last year the landfill accepted waste (for open landfills, enter the estimated year of landfill closure), the capacity (in metric tons) of the landfill, an indication of whether leachate recirculation isPage 25 of 39 used during the reporting year and its t ypical frequency of use over the past 10 years (e.g., used several times a year for the past 10 years, used at least once a year for the past 10 years, used occasionally but not every year over the past 10 years, not used), an indication as to whether scal es are present at the landfill, and the waste disposal quantity for each year of landfilling required to be included when using Equation HH

– 1 of this subpart (in metric tons, wet weight). (b) Method for estimating reporting year and historical waste dispos al quantities, reason for its selection, and the range of years it is applied. For years when waste quantity data are determined using the methods in §98.343(a)(3), report separately the quantity of waste determined using the methods in §98.343(a)(3)(i) an d the quantity of waste determined using the methods in §98.343(a)(3)(ii). For historical waste disposal quantities that were not determined using the methods in §98.343(a)(3), provide the population served by the landfill for each year the Equation HH

– 2 o f this subpart is applied, if applicable, or, for open landfills using Equation HH

– 3 of this subpart, provide the value of landfill capacity (LFC) used in the calculation. (c) Waste composition for each year required for Equation
HH

– 1 of this subpart, in p ercentage by weight, for each waste category listed in Table HH

– 1 to this subpart that is used inPage 26 of 39 Equation HH

– 1 of this subpart to calculate the annual modeled CH 4 generation (d) For each waste type used to calculate CH .

4 generation

(1) Degradable organic carbon (DOC ) , methane correction factor (MCF), ) and fraction of DOC dissimilated (DOC using Equation HH

– 1 of this subpart, you must report:

F

(2) Decay rate (k) value used in the calculations. ) values used in the calculations. If an MCF other than the default of 1 is used, provide an indic ation of whether active aeration of the waste in the landfill was conducted during the reporting year, a description of the aeration system, including aeration blower capacity, the fraction of the landfill containing waste affected by aeration, the total n umber of hours during the year the aeration blower was operated, and other factors used as a basis for the selected MCF value.

(e) Fraction of CH 4 in landfill gas (F) , an indication of whether the fraction of CH 4 was determined based on measured values or the default value , and the methane correction factor used in the calculations. If an MCF other than the default of 1 is used, provide an indication of whether active a eration of the waste in the landfill was conducted during the reporting year, a description of the aeration system, including aeration blower capacity, the fraction of the landfill containing waste affected by aeration, the total number of hours during the year thePage 27 of 39 aeration blower was operated, and other factors used as a basis for the selected MCF value. (f) The surface area of the landfill containing waste (in square meters), identification of the type of cover material used (as either organic cover, clay cover, sand cover, or other soil mixtures). If multiple cover types are used, the surface area associated with each cover type. (g) The modeled annual methane generation rate for the reporting year (metric tons CH 4

(h) For landfills without gas collection systems, the annual methane emissions (i.e., the methane generation, adjusted for oxidation, calculated using Equation HH

– 5 of this subpart), reported in metric tons CH ) calculated using Equation HH

– 1 of this subpart.

4

(i) For landfills with gas collection systems, you m ust report: , the oxidation fraction used in the calculation, and an indication of whether passive vents and/or passive flares (vents or flares that are not considered part of the gas collection system as defined in §98.6) are present at this landfill.

(1) Total volumetric flow of landfill gas collected for destruction for the reporting year (cubic feet at 520 °R or 60 degrees Fahrenheit and 1 atm).Page 28 of 39
(2) Annual average CH 4

(3) Monthly average temperature and pressure for each month at which flow is measured for landfill gas collected for destruction, or statement that temperature and/or pressure is incorporated into internal calculations run by the monitoring equipment. concentration of landfill gas collected for destruction (percent by volume).

(4) An indication as to whether flow was measured on a wet or dry basis, an indication as to whether CH 4 concentration

(5) An indication of whether destruction occurs at the landfill facility or , off

- site
. , or both
. If destruction occurs at the landfill facility, also report for each measurement location an indication of whether a back

- up destruction device is present at the landfill, the annual operating hours for the primary destruction device, the annual operating hours for the back

- up destru ction device (if present), and the destruction efficiency used (percent). was measured on a wet or dry basis, and if required for Equation HH

– 4 of th is subpart, monthly average moisture content for each month at which flow is measured for landfill gas collected for destruction.

(6) Annual quantity of recovered CH 4 (metric tons CH 4 ) calculated using Equation HH

– 4 of this subpart.Page 29 of 39 (7) A description of the gas collection system (manufacturer, capacity, and num ber of wells), the surface area (square meters) and estimated waste depth (meters) for each area specified in Table HH

– 3 to this subpart, the estimated gas collection system efficiency for landfills with this gas collection system, the annual operating hou rs of the gas collection system, and an indication of whether passive vents and/or passive flares (vents or flares that are not considered part of the gas collection system as defined in §98.6) are present at the landfill. (8) Methane generation corrected for oxidation calculated using Equation HH

– 5 of this subpart, reported in metric tons CH 4 ,

(9) Methane generation (G and the oxidation fraction used in the calculation
.

CH4 ) value used as an input to Equation HH

– 6 of this subpart. Specify whether the value is modeled (G CH4

(10) Methane generation corrected for oxidation calculated using Equation HH

– 7 of this subpart, reported in metric tons CH from HH

– 1 of this subpart) or measured (R from Equation HH

– 4 of this subpart).

4

(11) Methane emissions calculated using Equation HH

– 6 of this subpart, reported in metric tons CH , and the oxidation fraction used in the calculation
.

4 , and the oxidation fraction used in the calculation
.Page 30 of 39 (12) Methane emissions calculated using Equation HH

– 8 of this subpart, reported in metric tons CH 4 , and the oxidation fraction used in the calculation
.

In addition to the information required by §98.3(g), you must retain the calibration records for all monitoring equipme nt, including the method or manufacturer's specification used for calibration. You must retain records of all measurements made to determine tare weights and working capacities by vehicle/container type if these are used to determine the annual waste quant ities. § 98.347 Records that must be retained.

Except as specified in this section, all terms used in this subpart have the same meaning given in the Clean Air Act and subpart A of this part. § 98.348 Definitions.

Construction and demolition (C&D) waste landfill means a solid waste disposal faci lity subject to the requirements of part 257, subparts A or B of this chapter that receives construction and demolition waste and does not receive hazardous waste (defined in §261.3 of this chapter) or industrial solid waste (defined in §258.2 of this chap ter) or municipal solid waste (as defined in §98.6) other than residential lead

- based paint waste. A C&D waste landfill typically receives any one orPage 31 of 39 more of the following types of solid wastes: Roadwork material, excavated material, demolition waste, cons truction/renovation waste, and site clearance waste. Destruction device means a flare, thermal oxidizer, boiler, turbine, internal combustion engine, or any other combustion unit used to destroy or oxidize methane contained in landfill
gas. Industrial wast e landfill means any landfill other than a municipal solid waste landfill, a RCRA Subtitle C hazardous waste landfill, or a TSCA hazardous waste landfill, in which industrial solid waste, such a RCRA Subtitle D wastes (nonhazardous industrial solid waste, defined in §257.2 of this chapter), commercial solid wastes, or conditionally exempt small quantity generator wastes, is placed. An industrial waste landfill includes all disposal areas at the facility. Solid waste has the meaning established by the Admini strator pursuant to the Solid Waste Disposal Act (42 U.S.C.A. 6901 et seq
. ). Landfill capacity means the maximum amount of solid waste a landfill can accept. For the purposes of this subpart, for landfills that have a permit, the landfill capacity can be d etermined in terms of volume or mass in the most recent permit issued by the state, local, or Tribal agency responsible for regulating the landfill, plus any in

- place waste not accountedPage 32 of 39 for in the most recent permit. If the owner or operator chooses
to co nvert from volume to mass to determine its capacity, the calculation must include a site

- specific density. Leachate recirculation means the practice of taking the leachate collected from the landfill and reapplying it to the landfill by any of one of a variety of methods, including pre

wetting of the waste, direct discharge into the working face, spraying, infiltration ponds, vertic al injection wells, horizontal gravity distribution systems, and pressure distribution systems. Working capacity

**Table HH –**  **1 to Subpart HH of Part 98 —**  **Emissions Factors, Oxida tion**  **Factors and Methods** means the maximum volume or mass of waste that is actually placed in the landfill from an individual or representative type of container (such as a tank, truck, or roll

- off bin) used to convey wastes to the landfill, taking into account that the container may not be able to be 100 percent filled and/or 100 percent emptied for each load.

**Factor Default value**  **Units DOC and k values**  **— Bulk waste option**  DOC (bulk waste) 0.20 Weight fraction, wet basis. k (precipitation plus recirculated leachate a <20 inches/year) 0.02 yr −1Page 33 of 39

**Factor Default value**  **Units** k (precipitation plus recirculated leachate a 20

– 40 inches/year) 0.038 yr −1

k (precipitation plus recirculated leachate a >40 inches/year) 0.057 yr −1

**DOC and k values —**  **Modified bulk MSW option** DOC (bulk MSW, excluding inerts and C&D waste) 0.31 Weight fraction, wet basis. DOC (inerts, e.g., glass, plastics, metal, concrete) 0.00 Weight fraction, wet basis. DOC (C&D waste) 0.08 Weight fraction, wet basis. k (bulk MSW, excluding inerts and C&D waste) 0.02 to 0.057 b yr −1
k (inerts, e.g., glass, plastics, metal, concrete) 0.00 yr −1
k (C&D waste) 0.02 to 0.04 b yr −1 **DOC and k values —**  **Waste composition option** DOC (food waste) 0.15 Weight fraction, wet basis. DOC (garden) 0.2 Weight fraction, wet basis. DOC (paper) 0.4 Weight fraction, wet basis. DOC (wood and straw) 0.43 Weight fraction, wetPage 34 of 39

**Factor Default value**  **Units** basis. DOC (textiles) 0.24 Weight fraction, wet basis. DOC (diapers) 0.24 Weight fraction, wet basis. DOC (sewage sludge) 0.05 Weight fraction, wet basis. DOC (inerts, e.g., glass, plastics, metal, cement) 0.00 Weight fraction, wet basis. k (food waste) 0.06 to 0.185 c yr −1 k (garden) 0.05 to 0.10 c yr −1 k (paper) 0.04 to 0.06 c yr −1 k (wood and straw) 0.02 to 0.03 c yr −1 k (textiles) 0.04 to 0.06 c yr −1 k (diapers) 0.05 to 0.10 c yr −1 k (sewage sludge) 0.06 to 0.185 c yr −1 k (inerts e.g., glass, plastics, metal, concrete) 0.00 yr −1
**Other parameters —**  **All MSW landfills**
MCF 1. DOC F 0.5
F 0.5 OX 0.1 See Table HH

4 of this subpartPage 35 of 39

**Factor Default value**  **Units**
DE 0.99
a Recirculated leachate (in inches/year) is the total volume of leachate recirculated from company records or engineering estimates divided by the area of the portion of the landfill containing waste with appropriate unit conversions. Alternatively, landfills that use leachate recirculation can elect to use the k value of 0.057 rather than calculating the recirculated leachate rate. b Use the lesser value when precipitation plus recirculated leachate is less than 20 inches/year. Use the greater value when precipitation plus recirculated leachate is greater than 40 inches/year. Use the averag e of the range of values when precipitation plus recirculated leachate is 20 to 40 inches/year (inclusive). Alternatively, landfills that use leachate recirculation can elect to use the greater value rather than calculating the recirculated leachate rate.

c Use the lesser value when the potential evapotranspiration rate exceeds the mean annual precipitation rate plus recirculated leachate. Use the greater value when the potential evapotranspiration rate does not exceed the mean annual precipitation rate plus recirculated leachate. Alternatively, landfills that use leachate recirculation can elect to use the greater value rather than assessing the potential evapotranspiration rate or recirculated leachate rate.

**Table HH –**  **2 to Subpart HH of Part 98 —**  **U.S. Per Cap ita Waste**  **Disposal Rates**

**Year Waste per capita**  ton/cap/yr **% to SWDS**  1950 0.63 100 1951 0.63 100 1952 0.63 100 1953 0.63 100 1954 0.63 100 1955 0.63 100 1956 0.63 100 1957 0.63 100 1958 0.63 100 1959 0.63 100 1960 0.63 100 1961 0.64 100 Formatted Table Deleted CellsPage 36 of 39

**Year Waste per capita**  ton/cap/yr **% to SWDS**  1962 0.64 100 1963 0.65 100 1964 0.65 100 1965 0.66 100 1966 0.66 100 1967 0.67 100 1968 0.68 100 1969 0.68 100 1970 0.69 100 1971 0.69 100 1972 0.70 100 1973 0.71 100 1974 0.71 100 1975 0.72 100 1976 0.73 100 1977 0.73 100 1978 0.74 100 1979 0.75 100 1980 0.75 100 1981 0.76 100 1982 0.77 100 1983 0.77 100 1984 0.78 100 1985 0.79 100 1986 0.79 100 1987 0.80 100 1988 0.80 100 1989 0. 85 83 84 1990 0. 84 8 2 77 1991 0. 78 7 6 76 1992 0. 76 7 4 72 1993 0. 78 7 6 71 1994 0. 77 7 5 67 1995 0. 72 7 0 63 1996 0. 71 68 62 1997 0. 72 69 61 1998 0. 78 75 61 1999 0. 78 75 60 2000 0. 84 8 0 61 2001 0. 95 9 1 63 2002 1. 06 0 2 66 2003 1. 06 0 2 65 2004 1. 06 0 1 64 Formatted Table Deleted CellsPage 37 of 39

**Year Waste per capita**  ton/cap/yr **% to SWDS**  2005 1.06 0.98 64 2006 1.06 0.95 64 2007 0.95 2008 0.95 2009 and all later years 0.95 **Editorial Note:** At 75 FR 66474, October 28, 2010, Table HH

– 2 to subpart HH was amended; however, the amendment could not be incorporated as instructed.

**Table HH –**  **3 to Subpart HH of Part 98 —**  **Landfill Gas Collection Efficiencies** 
**Description Landfill Gas Collection**  **Efficiency** A1: Area with no waste in

- place Not applicable; do not use this area in the calculation. A2: Area without active gas collection, regardless of cover type CE2: 0%.

A3: Area with daily soil cover and active gas collection CE3: 60%.

A4: Area with an intermediate soil cover, or a final soil cover not meeting the criteria for A5 below, and active gas collection CE4: 75%.

A5: Area with a final soil cover of 3 feet or thicker of clay and/or geomembrane cover system and active gas collection CE5: 95%.

Ar ea weighted average collection efficiency for landfills CEave1 = (A2*CE2 + A3*CE3 + A4*CE4 + A5*CE5)/(A2+A3+A4+A5).

**Table HH –**  **4 to Subpart HH of Part 98**  **— Landfill**  **Methane Oxidation Fractions**  **If your methane flux rate a**  **for the reporting year is:**  **Use this l andfill**  **methane oxidation fraction:**  Formatted Table Deleted CellsPage 38 of 39

Less than 10 g rams per square meter per day (g/m 2 /d) 0.35
10 to 70 g/m 2 /d 0.25 Greater than 70 g/m 2 /d 0.10
a Methane flux rate (in g rams per square meter per day; g/m 2 /d) is the mass flow rate of methane per unit area at the bottom of the surface soil prior to any oxidation and is calculated as follows. For Equation HH

- 5 of this subpart, or for Equation TT

- 6 of subpart TT of this part, 

### SArea G K MF CH4 

### × **=**
For Equation HH

- 6 of this subpart, SArea R

- G K MF 1 n CH4 ** **  ** **  ** **  **× =**  

## ∑

**−** N

n For Equations HH

- 7 of this subpart, SArea f R CE

1 K MF 1 n Rec,

n ** **  ** **  ** **  ** **  ** **  ** **  ** **  ** **  **× =**  

## ∑

**−** N

n For Equation HH

- 8 of this subpart, SArea R f R CE

1 K MF 1 n 1 n Rec,

n ** **  ** **  ** **  ** ** 

**− **  ** **  ** **  ** **  ** **  ** **  ** **  ** **  ** **  ** ×**  **=** 

## ∑ **∑**

**− −**  N

n N

n Where:
MF = Methane flux rate from the landfill in the reporting year ( g rams per square meter per day, g/m 2 /d ).
K = unit conversion factor = 10 6 /365 (g/metric ton per days/year) or 10 6 /366 for a leap year.
SArea = The surface area of the landfill containing waste at the beginning of the reporting year (square meters, m 2 ).
G CH 4 = Modeled methane generation rate in reporting year from Equation HH

– 1 of this subpart, or, for application with Equation HH

- 6 only, the greater of the m odeled methane generation rate in reporting year from Equation HH

– 1 of this subpart and t he quantity o f Field Code Changed

Field Code Changed

Field Code Changed

Field Code ChangedPage 39 of 39

recovered CH 4 from Equation HH

– 4 of this subpart (metric tons CH 4 ).
CE = Collection efficiency estimated at landfill, taking into account system coverage, operation, and cover system materials from Table HH

– 3 of this subpart. If area by soil cover type information is not available, use default value of 0.75 (CE4 in table HH

– 3 of this subpart) for all areas under active influence of the collection system.
N = Number of landfill gas measurement locations (assoc i ated with a destruction device or gas sent off

site). If a single monitoring location is used to monitor volumetric flow and CH 4 concentration of the recovered gas sent to one or multiple destruction devices, then N =1.
R n = Quantity of recovered CH 4 from Equation HH

– 4 of this subpart for the n th measurement location (metric tons). f Rec , n = Fraction of hours the recovery system associated with the n th measurement location was operating (annual operating hours/8760 hours per year or annual operating hours/8 784 hours per year for a leap year ).