Page 1 of 39

**Subpart HH**

**— Municipal Solid Waste Landfills**  § 98.340 Definition of the source category. (a) This source category applies to municipal solid waste (MSW) landfills that accepted waste on or after January 1, 1980 , unless all three of the following conditions apply. (1) The MSW landfill did not receive waste on or after January 1, 2013. (2) The MSW landfill had CH 4 generation as determined using Equation HH
- 5 and, if applicable, Equation HH
- 7 of this subpart of less than 1,190 metric tons of CH 4 in the 2013 reporting year . (3) The owner or operator of the MSW landfill was not required to submit an annual report under any requirement of this part in any reporting year prior to 2013 . (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 landfills. (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). § 98.341 Reporting threshold.Page 2 of 39

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). § 98.342 GHGs to report. (a) You must report CH 4 generation and CH 4 emissions from landfills. (b) You must report CH 4 destruction resulting from landfill gas collection and combustion systems. (c) You must report under subpart C of this part (General Stationary Fuel Combustion Sources) the emissions of CO 2 , CH 4 , and N 2 O from each stationary combustion unit following the requirements of subpart C. § 98.343 Calculating GHG emissions. (a) For all landfills subject to the reporting requirements of this subpart, calculate annual modeled CH 4 generation according to the applicable requirements in paragraphs (a)(1) through (a)(3) of this section. (1) Calculate annual modeled CH 4 generation using Equation HH

– 1 of this section.

Where:
GCH4 = Modeled methane generation rate in reporting year T (metric tons CH 4 ). x = Year in which waste was disposed.Page 3 of 39

S = Start year of calculation. Use the year 1960 or the opening year of the landfill, whichever is more recent. T = Reporting year for which emissions are calculated. WX = 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)). MCF = Methane correction factor (fraction). Use the default value of 1 unless there is active aeration of waste within the landfill during the reporting yea r. 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 less than 0.5 based on site
- specific aeration parameters. DOC = Degradable organic carbon from Table HH

– 1 of this subpart [fraction (metric tons C/metric ton waste)]. DOC F = Fraction of DOC dissimilated (fraction). Use the default value of 0.5. F = Fraction by volume of CH 4 in landfill gas from measurement data for the current reporting year , if available (fraction , dry basis, corrected to 0 % oxygen ); otherwise, use the default of 0.5. k = Rate constant from Table HH

– 1 to this subpart (yr −1 ). Select the most applicable k value for the majority of the past 10 years (or operating life, whichever is shorter). (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 4 generation rates for all waste types t o calculate the total modeled CH 4 generation rate for the landfill. Use the appropriate parameter values for k,Page 4 of 39

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 are not available, use the bulk waste parameter 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 fo r each year thereafter, if scales are in place, 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 use d 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 sensitivity 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 mayPage 5 of 39

use either 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 monito ring plan. (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
u sing mass scales each vehicle or container after 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 o f 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;Page 6 of 39

determine a representative tare weight by vehicle or container type by weighing no le ss than 5 of each type of vehicle or container 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 t ype; and determine the annual quantity of waste received as the sum of all waste loads received during the year. (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. , using volumetric capacity and waste density measurements; 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 acro ss all of the vehicle/container types used to haul waste to the landfill. (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 wastePage 7 of 39

disposa l quantity data are not readily available, W 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 y our facility. Historical waste disposal quantities should only be determined once, as part of the first annual report, and the same values should be used for all subsequent annual reports, supplemented by the next year's data on new waste disposal. (i) Ass ume all prior years waste disposal quantities 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 w aste disposal rates found in Table HH

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

– 2 of this section.

Where:
WX = Quantity of waste placed in the landfill in year x (metric tons, wet basis). POP X = Population served by the landfill in year x from city population, census data, or other estimates (capita). WDRX = Average per capita waste disposal rate for year x from Table HH

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

Where :
WX = Quantity of waste placed in the landfill in year x (metric tons, wet basis). 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 drawings or engineering estimates (metric tons). 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 avai lable from company records, or best available 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 ope rating life of the landfill.
(b) For landfills with gas collection systems, calculate the quantity of CH 4 destroyed according to the requirements in paragraphs (b)(1) and (b)(2) of this section.Page 9 of 39

(1) If you continuously monitor the flow rate, CH 4 concentra tion , 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 reports CH 4 content requires no other calculation than summing the results of all monitoring periods 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) Where:
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 month ly sampling, as provided in paragraph (b)(2) of this section, use N= 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 /1 atm” with “1”. (KMC ) n = Moisture correction term for the measurement period, volumetric basis, as follows: (KMC ) n= 1 when (V) nand (C) nare both measured on a dry basis or if both are measured on a wet basis; (KMC ) n= [1
- (f H2 O ) n ] when (V) n is measured on a wetPage 10 of 39 basis and (C) n is measured on a dry basis; and (KMC ) n= 1/[1
- (f H2O ) n ] when (V) n is measured on a dry basis and (C) n is measured on a wet basis. (f H2 O ) n = Average moisture content of landfill gas during the measurement period, volumetric basis (cubic feet water per cubic feet landfill gas) (C CH4 ) n = Average CH 4 concentration of landfill gas for the measurement period (volume %). 0.0423 = Density of CH 4 lb/cf at 520°R or 60 degrees Fahrenheit and 1 atm. (T) n = Average temperature at which flow is measured for the measurement period (°R). (P) n = Average pressure at which flow is measured for the measurement period (atm). 0.454/1,000 = Conversion factor (metric ton/lb). (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 recovered for destruction using Equation HH

– 4 of this section. (i) Continuously monitor gas flow rate and determine the cumulative volume of landfill gas each 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 is not required to automatically correct for temperature, pressure, or, if necessary, moisturePage 11 of 39

content. If the gas flow meter is not equipped with automatic correction for temperature, pressure, or, if necessary, moisture content, you must determine these parameters as specified in paragraph (b)(2)(iii) of this section. (ii) Determine the CH 4 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 location of the gas flow meter at least once each calendar month ; if only one measuremen t is made each calendar month , there must be at least fourteen days between measurements. (iii) If the gas flow meter is not equipped with automatic correction for temperature, pressure, or, if necessary, moisture content: (A) Determine the temper ature 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 month ; if only one measu rement is made each calendar month , there must be at least fourteen days between measurements. (B) If the CH 4 concentration is determined on a dry basis and flow is determined on a wet basis or CH 4 concentration is determined on a wet basis and fl ow 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 thatPage 12 of 39

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 month ; if only one measurement is made each calendar month , there must be at least 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 recovery, and oxidation in cover materials) according to the applicable methods in paragraphs (c)(1) through (c)(3) of this section. (1) Calculat e CH 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 ).

GCH4 = 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 .Page 13 of 39

(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. (3) For landfills with landfill gas collection systems, calculate CH 4 emissions using the methodologies sp ecified in paragraphs (c)(3)(i) and (c)(3)(ii) of this section. (i) Calculate CH 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 ). GCH 4 = Modeled methane generation rate in reporting year from Equation HH

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

– 4 of this section , whichever is greater (metr ic tons CH 4 ). 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. Rn = Quantity of recovered CH 4 from Equation HH

– 4 of this section for the n th measurement location (metric tons).Page 14 of 39

OX = Oxidation fraction. Use the appropriate oxidation fraction default value from Table HH - 4 of thi s subpart . DE n = Destruction efficiency (lesser of manufacturer's specified destruction 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 single 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 as the arithmetic average of the DE values determined for each destruction device associated with that measurement location. f 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 operati ng 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 . If the gas is transported off
- site for destruction, use f Dest ,n= 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 destroyed 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. (ii) Calculate CH 4 generation and CH 4 emissions using measured CH 4 recovery and estimated gas collection efficiency and Equations HH

– 7 and HH

– 8 of this sectio n. 

### OX)
- (1 f R CE 1 MG 1 n Rec, n 

###         
 

# 

 N

n (Eq. HH
- 7)Page 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 single monitoring location is used to monitor volumetric flow and CH 4 concentration of the recovered gas se nt to one or multiple destruction devices, then N=1. Rn = 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 s ystem. 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 78 4 hours per year for a leap year ) . OX = Oxidation fraction. Use appropriate oxidation fraction default value from Table HH
- 4 of this subpart . DE n = Destruction efficiency, (lesser of manufacturer's specified destruction efficiency and 0.99 ) for the n th measurement location . If the gas is transported off
- sitePage 16 of 39 for destruction, use DE = 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 destroyed on
- site and s ome gas sent off
- site for destruction), calculate DE n as the arithmetic average of the DE values determined for each destruction device associated with that measurement location. f 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. If the gas is transported off
- site for destruction, use f Dest ,n= 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 destroyed 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. § 98.344 Monitoring and QA/QC requirements. (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 Measuring Devices” NIST Handbook 44 (2009) (incorporated by reference, see §98.7). (b) For landfills with gas collec tion systems, operate, maintain, and calibrate a gas composition monitor capable of measuring the concentration of CH 4 in the recovered landfill gasPage 17 of 39

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 annually or at the minimum frequency specified by the manufacturer, whichever is more frequent, or whenever the error in the midrange ca libration check exceeds ± 10 percent. (1) Method 18 at 40 CFR part 60, appendix A

– 6. (2) ASTM D1945

– 03, Standard Test Method for Analysis of Natural Gas by Gas Chromatography (incorporated by reference,
see §98.7). (3) ASTM D1946

– 90 (Reapproved 2006), Stan dard 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 and calculate the methane concentration following the requirements in paragraphs (b)(6)(i) through (b)(6)(iii) of this section.Page 18 of 39

(i) Use Method 25A or 25B at 40 CFR part 60, appendix A

– 7 to determine total gaseous organic concentration. You must calibrate the instrument with methan e 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 f requently than once a reporting year following the requirements in paragraphs (b)(6)(ii)(A) through (b)(6)(ii)(C) of this section. (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 section. (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 as specified in paragraph (b)(6)(i) of this section. (C) Determine the arithmetic average methane concentration and the arithmetic ave rage total gaseous organic concentration of the samples analyzed according to paragraphs (b)(6)(ii)(A) and (b)(6)(ii)(B) of this section, respectively, and calculatePage 19 of 39

the non
-methane organic carbon correction factor as the ratio of the average methane conce ntration to the average total gaseous organic concentration. If the ratio exceeds 1, use 1 for the
non -methane organic carbon correction factor. (iii) Calculate the methane concentration as specified in Equation HH

– 9 of this section.

Where:
C CH4 = Methan e concentration in the landfill gas (volume %) for use in Equation HH

– 4 of this subpart. fNMOC = 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). C TGOC = Total gaseous organic carbon concentration measured using Method 25A or 25B at 40 CFR part 60, appendix A

– 7 during routine monitoring of the landfill gas (volume %). (c) For landfills with gas collection system s, install, operate, maintain, and calibrate a gas flow meter capable of measuring the volumetric flow rate of the recovered landfill gas using one of the methods specified in paragraphs (c)(1) through (c)(8) of this section or as specified by the manufact urer. Each gas flow meter shall be recalibrated either biennially (every 2 years) or at the minimum frequency specified by the manufacturer. Except as provided in §98.343(b)(2)(i), each gasPage 20 of 39

flow meter must be capable of correcting for the temperature and p ressure 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 Mete rs (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 Ve nturi 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 (incorp orated 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 necessary, moisture content monitors must be calibrated using the procedures and frequencies specified by the manufacturer. (e) Fo r landfills electing to measure the fraction by volume of CH 4 in landfill gas (F), follow the requirements in paragraphs ( e )(1) and ( e )(2) of this section. (1) Use a gas composition monitor capable of measuring the concentration of CH 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 f or 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. (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 measurement 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 )Page 22 of 39

Where:
F = Fraction by volume of CH 4 in landfill gas (fraction, dry basis, corrected to 0% oxygen). C CH4 = Measured CH 4 concentration in landfill gas (volume %, dry basis). 20.9 c = Defined O 2 correction basis, (volume %, dry basis). 20.9 = O 2 concentration in air (volume %, dry basis). %O 2 = Measured O 2 concentration in landfill gas (volume %, dry basis). (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 devices and the technical basis for these accuracy estimates shall be recorded . § 98.345 Proc edures for estimating missing data. 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 un it operation or if a required fuel sample is not taken), a substitute data value for the missing parameter shall be used in the calculations,Page 23 of 39

according to the requirements in paragraphs (a) through (c) of this section. (a) For each missing value of the CH 4 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 “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 to the missing data incident, the substitute data value shall be the first quality
- assured value obtained af ter the missing data period. (b) For missing gas flow rates, 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 “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 to the missing data incident, the substitute data value s hall 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 year, the substitute value shall bePage 24 of 39

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. § 98.346 Data reporting requirements. In addition to the information required by §98.3(c), each annual report must contain the following information for each landfill. (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 disposal, the last year the landfill accepted waste (fo r open landfills, enter the estimated year of landfill closure), the capacity (in metric tons) of the landfill, an indication of whether leachate recirculation is used during the reporting year and its typical 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 scales are present at the landfill, and the waste disposa l 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 disposal quantities, reason for its selection, and thePage 25 of 39

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) and 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 of this subpart is applied, if applicable, or, for ope n 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 percentage by weight, for each waste category listed i n Table HH

– 1 to this subpart that is used in 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 using Equation HH

– 1 of this subpart, you must report: (1) Degradable organ ic carbon (DOC ) and fraction of DOC dissimilated (DOC F ) values used in the calculations. (2) Decay rate (k) value used in the calculations. (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 factorPage 26 of 39

used in the calculations. If an MCF other than the default of 1 is used, provide an indication of whether active aeration of the waste in the landfill was conducted during the reporting year, a description of the ae ration system, including aeration blower capacity, the fraction of the landfill containing waste affected by aeration, the total number of hours during the year the 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 assoc iated with each cover type. (g) The modeled annual methane generation rate for the reporting year (metric tons CH 4 ) calculated using Equation HH

– 1 of this subpart. (h) For landfills without gas collection systems, the annual methane emissions (i.e., the me thane generation, adjusted for oxidation, calculated using Equation HH

– 5 of this subpart), reported in metric tons CH 4 , the oxidation fraction used in the calculation, and an indication of whether passive vents and/or passive flares (vents or flares that a re not considered part of the gas collection system as defined in §98.6) are present at this landfill.Page 27 of 39

(i) For landfills with gas collection systems, you must report: (1) Total volumetric flow of landfill gas collected for destruction for the reporting yea r (cubic feet at 520 °R or 60 degrees Fahrenheit and 1 atm). (2) Annual average CH 4 concentration of landfill gas collected for destruction (percent by volume). (3) Monthly average temperature and pressure for each month at which flow is measured for landf ill gas collected for destruction, or statement that temperature and/or pressure is incorporated into internal calculations run by the monitoring equipment. (4) An indication as to whether flow was measured on a wet or dry basis, an indication as to whethe r CH 4 concentration was measured on a wet or dry basis, and if required for Equation HH

– 4 of this subpart, monthly average moisture content for each month at which flow is measured for landfill gas collected for destruction. (5) An indication of whether de struction occurs at the landfill facility , off
- site , or both . If destruction occurs at the landfill facility, also report for each measurement location the number of destruction devices associated with that measurement location and the annual operating hours and thePage 28 of 39

destruction efficiency (percent) for each destruction device associated with that measurement location . (6) Annual quantity of recovered CH 4 (metric tons CH 4 ) calculated using Equation HH

– 4 of this subpart for each measurement location . (7) A description of the gas collection system (manufacturer, capacity, and number 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 coll ection system, the annual operating hours of the gas collection system for each measurement location , 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 , and the oxidation fraction used in the calculation . (9) Methane generation (GCH4 ) value used as an input to Equation HH

– 6 of this subpart. Specify whether the value is modeled (GCH4 from HH

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

– 4 of this subpart).Page 29 of 39

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

– 7 of this subp art, reported in metric tons CH 4 , and the oxidation fraction used in the calculation . (11) Methane emissions calculated using Equation HH

– 6 of this subpart, reported in metric tons CH 4 , and the oxidation fraction used in the calculation . (12) Methane emis sions calculated using Equation HH

– 8 of this subpart, reported in metric tons CH 4 , and the oxidation fraction used in the calculation . § 98.347 Records that must be retained. In addition to the information required by §98.3(g), you must retain the calibration records for all monitoring equipment, 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 quantities. § 98.348 Definitions. 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. Construction and demolition (C&D) waste landfill means a solid waste disposal facility subject to the requirements of part 257, subparts A or B of this chapter that receivesPage 30 of 39

construction and demolition waste and does no t receive hazardous waste (defined in §261.3 of this chapter) or industrial solid waste (defined in §258.2 of this chapter) or municipal solid waste (as defined in §98.6) other than residential lead
-based paint waste. A C&D waste landfill typically receive s any one or more of the following types of solid wastes: Roadwork material, excavated material, demolition waste, construction/renovation waste, and site clearance waste. Destruction device means a flare, thermal oxidizer, boiler, turbine, internal combus tion engine, or any other combustion unit used to destroy or oxidize methane contained in landfill gas. Industrial waste landfill means any landfill other than a municipal solid waste landfill, a RCRA Subtitle C hazardous waste landfill, or a TSCA hazardou s 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 indus trial waste landfill includes all disposal areas at the facility. Solid waste has the meaning established by the Administrator pursuant to the Solid Waste Disposal Act (42 U.S.C.A. 6901 et seq . ).Page 31 of 39

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 determined in terms of volume or mass in the most recent permit issued by the state, local, or T ribal agency responsible for regulating the landfill, plus any in
-place waste not accounted for in the most recent permit. If the owner or operator chooses to convert from volume to mass to determine its capacity, the calculation must include a site
- specif ic 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, sp raying, infiltration ponds, vertical injection wells, horizontal gravity distribution systems, and pressure distribution systems. Working capacity means the maximum volume or mass of waste that is actually placed in the landfill from an individual or repre sentative 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.Page 32 of 39

**Table HH –**  **1 to Subpart HH o f Part 98** **— Emissions Factors, Oxidation**  **Factors and Methods 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 −1

k (precipitation plus recirculated leachate a20

– 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, wetPage 33 of 39

**Factor Default value**  **Units** 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, wet 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 −1Page 34 of 39

**Factor Default value**  **Units Other parameters** **— All MSW landfills**  MCF 1. DOC F 0.5 F 0.5 OX See Table HH
- 4 of this subpart DE 0.99 aRecirculated 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. bUse 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 average 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.
cUse 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 Capi ta Waste**  **Disposal Rates Year**  **Waste per capita** ton/cap/yr 1950 0.63 1951 0.63Page 35 of 39

**Year Waste per capita**  ton/cap/yr 1952 0.63 1953 0.63 1954 0.63 1955 0.63 1956 0.63 1957 0.63 1958 0.63 1959 0.63 1960 0.63 1961 0.64 1962 0.64 1963 0.65 1964 0.65 1965 0.66 1966 0.66 1967 0.67 1968 0.68 1969 0.68 1970 0.69 1971 0.69 1972 0.70 1973 0.71 1974 0.71 1975 0.72 1976 0.73 1977 0.73 1978 0.74 1979 0.75 1980 0.75 1981 0.76 1982 0.77 1983 0.77 1984 0.78 1985 0.79 1986 0.79 1987 0.80 1988 0.80 1989 0. 83 1990 0. 8 2 1991 0. 7 6 1992 0. 7 4 1993 0. 7 6 1994 0. 7 5Page 36 of 39

**Year Waste per capita**  ton/cap/yr 1995 0. 7 0 1996 0. 68 1997 0. 69 1998 0. 75 1999 0. 75 2000 0. 8 0 2001 0. 9 1 2002 1. 0 2 2003 1. 0 2 2004 1. 0 1 2005 0.98 2006 0.95 2007 0.95 2008 0.95 2009 and all later years 0.95

**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%.

Area weighted average collection CEave1 = (A2*CE2 + A3*CE3 +Page 37 of 39

**Description Landfill Gas Collection**  **Efficiency** efficiency for landfills A4*CE4 + A5*CE5)/(A2+A3+A4+A5).
**Table HH –** **4 to Subpart HH of Part 98** **— Landfill**  **Methane Oxidation Fractions** 

**Under these conditions**  **: Use this l** **andfill methane oxidation**  **fraction:** I.For all reporting years prior to the 2013 reporting year C1: For all landfills regardless of cover type or methane flux 0.10 II. For the 2013 reporting year and all subsequent years
 C2: For landfills that have a geomembrane (synthetic) cover with less than 12 inches of cover soil for the majority of the landfill area containing waste  0.0

C3: For landfills that do not meet the conditions in C2 above, and for which you elect not to determine methane flux 0.10

C4: For landfills that do not meet the conditions in C2 above and that do not have a soil cover of at least 24 inches for a majo rity of the landfill area cont a i ning waste 0.10

C5: For landfills that have a soil cover of at least 24 inches for a majority of the landfill area containing waste and for which the methane flux rate is less than 10 grams per square meter per day (g/m2 /d) 0.35

C6: For landfills that have a soil cover of at least 24 inches for a majority of the landfill area containing waste and for which the methane flux rate is 10 to 70 g/m2 /d 0.25

C7: For landfills that have a soil cover of at least 24 inches for a majority of the 0.10Page 38 of 39

landfill area containing waste and for which the methane flux rate is greater than 70 g/m2 /d aMethane flux rate (in grams per square meter per day; g/m2 /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 ( grams per square meter per day, g/m2 /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 wa ste at

the beginning of the reporting year (square meters, m2 ). GCH 4 = Modeled methane generation rate in reporting year from

Equation HH

– 1 of this subpart or Equation TT
- 1 of subpart TT of this part, as applicable, except for application with Equation HH - 6 of this subpart (metric tons CH 4 ). For application with Equation HH
- 6 of this subpart, the greater of the modeled methane generation rate in reporting year from Equation HH

– 1 of thisPage 39 of 39 subpart or Equation TT
- 1 of this part, as applicable, and the quanti ty of 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. Rn = 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 ye ar ).