**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 an y requirement of this part in any reporting year prior to 2013. (b) This s ource 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: L andfills, landfill gas collection s ys tems, and landfill gas destruction devices (including flares). **§98.341 Reporting threshold.**  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 sy stems.(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 Cal**  **culating 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: 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 the year 1960 or the opening ye ar of the landfill, whichever is more recent. T = Reporting ye ar for which emissions are calculated. W X = Quantity

of waste disposed in the landfill in year × from measurement data, tipping fee receipts, or other company records (metric tons, as received (wet w eight)). MCF = Methane correction factor (fraction). Use the default value of 1 unless there is active

aeration of waste within the landfill during the reporting ye ar. If there is active aeration of waste within the landfill during the reporting ye ar, 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 di ssimilated (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 ye ar, 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 (y r−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 t ype and sum the CH 4 generation rates for all waste ty pes 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 o f this subpart. The annual quantity of each t ype of waste disposed must be calculated as the sum of the daily quantities of waste (of that t ype) disposed. You may use the bulk waste parameters for a portion of your waste materials when using the material

- s pecific modeling approach for mixed waste streams that cannot be designated to a specific material ty pe. 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 y ears. (3) Beginning in the first emissions reporting ye ar and for each ye ar 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 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 ph ys ic al limitations (loadcannot ph ys icall y 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 d etermine the annual quantity of waste disposed. For waste hauled to the landfill in passenger cars or light duty pickup trucks, you may use either paragraph (a)(3)(i) or paragraph (a)(3)(ii) of this section to determine the annual quantity of waste dispose d. For loads that cannot be measured using the scales due to phy sical 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. (i) Use direct mass measurements of each individual load received at the landfill using either of the following methods: (A) Weigh using mass sc ales each vehicle or container used to haul waste as it enters the landfill or disposal area; weigh using 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 diff erence in the two mass measurements; and determine the annual quantity of waste received as the sum of all waste loads received during the ye ar. Alternatively , you may determine annual quantity of waste b y 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 t yp e b y weighing no less than 5 of each typ e 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 themeasured weight in and the tare weight determined for that container/vehicle ty pe; and determine the annual quantit y of waste received as the sum of all waste loads received during the ye ar. (ii) Determine the working capacity in uni ts of mass for each t ype of container or vehicle used to haul waste to the landfill ( e.g., using volumetric capacit y 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 ty

pe; calc ulate the annual mass per vehicle/container typ e as the mass product of the number of loads of that vehicle/container multiplied by its working capacit y; and calculate the annual quantit y of waste received as the sum of the annual mass per vehicle/containe r t ype across all of the vehicle/container ty pes 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 readil y available. When wa ste disposal 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 h istory of your 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 dispos al. (i) Assume all prior ye ars 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 b y the landfill in each year, the values for national average p er capita waste disposal rates found in Table HH

- 2 to this subpart, and calculate the waste quantity

landfilled using Equation HH

- 2 of this section.where:

W X = 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). WDR X = 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/y r). (iii) Use a constant average waste disposal quantity calculated using Equation HH

- 3 of this section for each ye ar the landfill was in operation (i.e., from the first ye ar accepting waste until the last year for which waste disposal data is unavailable, inclusive).

where: W X = 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 disp osal data is first available 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 y e ars as the default operating life of the landfill.(b) For landfills with gas collection sy stems, calculate the quantity of CH 4 destroyed according to the requirements in paragraphs (b)(1) and (b)(2) of this section. (1) If you continuously

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

- 4 of this section. A fully integrated s ys tem that directly reports CH 4 content requires no other calculation than summing the resu lts of all monitoring periods for a given ye ar.

where: R = Annual quantity

of recovered CH 4 (metric tons CH 4 ). N = Total number of measurement periods in a ye ar. Use dail y averaging periods for a

continuous monitoring system and N = 365 (or N = 366 for l eap years). For monthly sampling, as provided in paragraph (b)(2) of this section, use N=12. 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 cor rects 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) n and (C) n are both measured on a dry basis or if both are
measur ed on a wet basis; (KMC ) n = [1

- (f H2O ) n ] when (V) n is measured on a wet basisand (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 H2O ) n = Average moisture content of lan dfill 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 = Densit y 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 destructio n 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 ga s flow rate and determine the cumulative volume of landfill gas each month and the cumulative volume of landfill gas each ye ar that is collected and routed to a destruction device (before an y treatment equipment). Under this option, the gas flow meter is n ot 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 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 an y treatment equipment) in a location near or representative of the locatio n 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 day s 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 temperature and pressure in the landfill gas that is collected and routed to a destruction device (before an y 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 day s between measurements. (B) If the CH 4 concentration is determined on a dry basis and flow is determined on a wet bas is 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 destruc tion 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 day s between mea surements. (c) For all landfills, calculate CH 4 generation (adjusted for oxidation in cover materials) and actual CH 4 emissions (taking into account an y CH 4 recovery , and oxidation in cover materials) according to the applicable methods in paragraphs (c)(1 ) through (c)(3) of this section. (1) Calculate CH 4 generation, adjusted for oxidation, from the modeled CH 4 (G CH4 from Equation HH

- 1 of this section) using Equation HH

- 5 of this section.Where:

MG = Methane generation, adjusted for oxidation, from the l andfill in the reporting ye ar (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. (2) For landfills that do not have landfill gas collection sy stems, 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 sy stems, calculate CH 4 emi ssions using the methodologies specified 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.

Where: Emissions = Methane emissio ns from the landfill in the reporting ye ar (metric tons CH 4 ). G CH4 = 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 (metric tons CH 4 ). N = Number of landfill gas measurement locations (associated 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 destr uction devices, then N=1.R

n = Quantity

of recovered CH 4 from Equation HH

- 4 of this section for the nth measurement location (metric tons). OX = Oxidation fraction. Use the 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 nth 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 destro yed on

- site and some gas sent off

- site for destruction), calculate DE n as the arithmetic average of the DE values determined for each destruc tion device associated with that measurement location. f Dest,n = Fraction of hours the destruction device associated with the nth 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 nth 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 measur ed 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 destructio n 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 section.Where:

MG = Methane generation, adjusted for oxidation, from the landfill in the reporting ye ar (metric tons CH 4 ). Emissions = Methane emissions from the landfill in the reporting y ear (metric tons CH 4 ). N = Number of landfill gas measurement locations (associated 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 section for the nth measurement location (metric tons CH 4 ). CE = Collection efficiency estimated at landfill, taking into account s ys tem coverage, operation, and cover s ys tem materials from Table HH

- 3 of this subpart. If area b y soil cover t ype information is not availabl e, use default value of 0.75 (CE4 in table HH

- 3 of this subpart) for all areas under active influence of the collection sy stem. f Rec,n = Fraction of hours the recovery s ys tem associated with the nth measurement location was operating (annual operating hour s/8760 hours per year or annual operating hours/8784 hours per ye ar 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 specifi ed destruction efficiency and 0.99) for the nth 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 destro yed 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 D est,n = Fraction of hours the destruction device associated with the nth 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 destruct ion device as measured at the nth 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 multipl e 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 collection sy stems, operate, maintain, and calibrate a gas composition monitor capable of measuring th e concentration of CH 4 in the recovered landfill gasusing one of the methods specified in paragraphs (b)(1) through (b)(6) of this section or as

specified b y the manufacturer. Gas composition monitors shall be calibrated prior to the first reporting year and recalibrated either annuall y or at the minimum frequency specified b y the manufacturer, whichever is more frequent, or whenever the error in the midrange calibration check exceeds ±10 percent. (1) Method 18 at 40 CFR part 60, appendix A

- 6. (2) ASTM D19 45

- 03, Standard Test Method for Analy sis of Natural Gas by Gas Chromatograph y (incorporated b y reference, see §98.7). (3) ASTM D1946

- 90 (Reapproved 2006), Standard Practice for Anal ys is of Reformed Gas by Gas Chromatograph y (incorporated b y reference, see §98.7). (4) GPA Standard 2261

- 00, Analy sis for Natural Gas and Similar Gaseous Mixtures by Gas Chromatograph y. (5) UOP539

- 97 Refinery Gas Anal ys is by Gas Chromatograph y (incorporated by reference, see §98.7). (6) As an alternative to the gas chromatograph y 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. (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 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 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 CF R 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 average total gaseous organic concentration of the samples anal yz ed 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 carbon correction factor. (iii) Calculate the methane concentration as specified in Equation HH

- 9 of this section.

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

- 4 of this

subpart.f

NMOC = N on - 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 sy stems, 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 b y the manufacturer. 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 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 Pi pes Using Orifice, Nozzle, and Venturi (incorporated b y reference, see §98.7). (2) ASME MFC

- 4M

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

- 6M

- 1998, Measurement of Fluid Flow in Pipe s Using Vortex Flowmeters (incorporated b y reference, see §98.7). (4) ASME MFC

- 7M
- 1987 (Reaffirmed 1992), Measurement of Gas Flow by Means of Critical Flow Venturi Nozzles (incorporated b y reference, see §98.7). (5) ASME MFC

- 11M

- 2006 Measurement of Fluid F low 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 Smal l Bore Precision

Orifice Meters (incorporated b y reference, see §98.7). (7) ASME MFC

- 18M

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

- 1. (d) All temperature, pressure, and if necessary , moisture content monitors must be calibrated using the procedures and frequencies specified b y the manufacturer. (e) For landfills electing to measure the fraction by volume of CH 4 in landfill gas (F), follow the requirements in paragraphs (e)(1) and (2) of this section. (1) Use a gas composition monitor capable of measuring the concentration of CH 4 on a dry basis that is properl y operated, calibrated, and maintained according to the requirements specified in paragraph (b) o f 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 concentr ation 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 s eparatel y for each measurement made during the reporting ye ar, and use the results to determine the arithmetic average value of F for use in Equation HH

- 1 of this part.

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, p ressure, 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 techni cal basis for these estimates shall be recorded. **§98.345 Procedures 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 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. (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 ye ar, you may use the “before” value for the missing data substitution. I f, 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 after 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. I f, 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 after the missing data period. (c) For missing daily

waste disposal quantity

data for disposal in the reporting ye ar, 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. **§98.346 Data reporting requirements.**  In addition to the information required b y §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 d isposal, the last year the landfill accepted waste (for open landfills, enter the estimated ye ar of landfill closure), the capacit y (in metric tons) of the landfill, an indication of whether leachate recirculation is used during the reporting year and its ty pical frequency

of use over the past 10 years (e.g., used several times a ye ar for the past 10 years, used at least once a ye ar for the past 10 years, used occasionally but not every

year over the past 10 years, not used), an indication as to whether sca les are present at the landfill, and the waste disposal quantity for each ye ar 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 dispo sal 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) 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 b y the landfill for each ye ar the Equation HH

- 2 of 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 ye ar required for Equation HH

- 1 of this subpart, in percentage b y weight, for each waste category listed in 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 t yp e used to calculate CH 4 generation using Equation HH

- 1 of this subpart, you must report: (1) Degradable organic 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 whethe r the fraction of CH 4 was determined based on measured values or the default value, and the methane correction factor (MCF) used in the calculations. I f an MCF other than the default of 1 is used, provide an indication of whether active aeration of the was te 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 theye ar 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 ty pe (s) of cover material used (as either organic cover, clay cover, sand co ver, or other soil mixtures). (g) The modeled annual methane generation rate for the reporting ye ar (metric tons CH 4 ) calculated using Equation HH

- 1 of this subpart. (h) For landfills without gas collection s ys tems, 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 4 , 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 sy stem as defined in §98.6) are present at this landfill. (i) For landfills with gas collection sy stems, you must report: ( 1) Total volumetric flow of landfill gas collected for destruction for the reporting ye ar (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 landfill gas collected for destruction, or statement that temperature and/or pressure is incorporated into internal calculations run b y the monitoring equipment. (4) An indi cation as to whether flow was measured on a wet or dry basis, an indication as to whether CH 4 concentration was measured on a wet or dry basis, and if required for EquationHH
- 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 destruction occurs at the landfill facility, off

- site, or both. If destruction occurs at the landfill facility , also report for each measurement location : (i) T he number of destruction devices associated with th e measurement location

. (ii) T he annual operating hours of the gas collection sy stem associated with th e measurement location, (i i i) For each destruction device associated with th e measurement location , report: (A) T he destruction efficiency ( decimal )

. (B) T he annual operating hours where active gas flow was sent to the destruction device

. (6) Annual quantit y 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 s ys tem (manufacturer, capacit y, 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 s ys tem efficiency for landfills with this gas collection sy stem and an indication of whether the gas collection efficiency was determined on an area

- weighte d average basis (Option 1) or a volume

- weighted average basis (Option 2) , and an indication of whether passive vents and/or passive flares (vents or flares that are not considered part of the gas collection sy stem 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 th e calculation.(9) Methane generation (G CH4 ) value used as an input to Equation HH

- 6 of this subpart.

Specify whether the value is modeled (G CH4 from HH

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

- 4 of this subpart). (10) Methane generation correcte d for oxidation calculated using Equation HH

- 7 of this subpart, 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 oxi dation fraction used in the calculation. (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. (13) Methane emissions for the landfill (i.e., the subpart HH total methane emissions )

. Choose the methane emissions from either Equation HH

- 6 of this subpart or Equation HH

- 8 of this subpart that best represents the emissions from the landfill. I f the quantity of recovered CH 4 from Equation HH

- 4 of this subpart is u sed as the value of G CH4 in Equation HH

- 6 of this subpart , use the methane emissions calculated using Equation HH

- 8 of this subpart as the methane emissions for the landfill

. **§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 t ype 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. Ac tive venting means a pipe or a s ys tem of pipes used with a fan or similar mechanical draft equipment (forced convection) used to activel y assist the flow of landfill gas to the surface of the landfill where the landfill gas is discharged either directly to the atmosphere or to a non

combustion control device (such as a carbon absorber) and then to the atmosphere. Alternative final cover means materials, other than soil, used at a landfill that meets final closure regulations of the competent federal, state, or local authorit y. Alternative final covers may include, but are not limited to, evapotranspiration covers, capillary barrier covers, asphalt covers, or concrete covers. The state, local, or other agency responsible for permitting the landfill determines whether an alternative final cover meets the applicable regulatory requirements and has been shown to adequatel y protect human health and the environment. 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 receives construction and demolition waste and does not receive hazardous waste (defined in §261.3 of this chapter) or industrial solid was te (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 ty picall y receives an y one or more of the following t ypes of solid wastes: Roadwork material, excavate d material, demolition waste, construction/renovation waste, and site clearance waste. Destruction device means a flare, thermal oxidizer, boiler, turbine, internal combustion engine, or an y other combustion unit used to destroy or oxidize methane containe d in landfill gas.Industrial waste landfill means an y 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

. Intermediate or interim cover means the placement of material over waste in a landfill for a period of time prior to the disposal of additional waste and/or final closure as defined by state regulation, permit, guidance or written plan, or state accepted best management prac tice

. 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 issue d by the state, local, or Tribal 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

- specific density

. Leachate recirculation means the practice of taking the leachate collected from the landfill and reappl yi ng it to the landfill by an y of one of a variet y of methods, including pre

- wetting of the waste, direct discharg e into the working face, spraying, infiltration ponds, vertical injection wells, horizontal gravit y distribution sy stems, and pressure distribution sy stems. Passive vent means a pipe or a s ys tem of pipes that allows landfill gas to flow naturall y, without the use of a fan or similar mechanical draft equipment, to the surface of the landfill where an opening or pipe (vent) allows for the free flow of landfill gas to the atmosphere or to a passive vent flare without diffusion through the top layer of surface soil.Solid waste has the meaning established b y the Administrator pursuant to the Solid Waste

Disposal Act (42 U.S.C.A. 6901 et seq. ). Working capacity means the maximum volume or mass of waste that is actually placed in the landfill from an individual or representative t ype 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. [75 FR 66473, Oct. 2 8, 2010, as amended at 78 FR 71970, Nov. 29, 2013] **Table HH -**  **1 to Subpart HH of Part 98**

**— Em**  **issions 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 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 MS**  **W 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, wetbasis.

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−1 **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 compan y records or engineering estimates divided by the area of the portion of the landfill containing waste with appropriate unit conversions. Alternativel y, landfills that use leachaterecirculation 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 average of the range of values when precipitation plus recirculated leachate is 20 to 40 inches/year (inclusive). Alternativel y, 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 rec irculated leachate. Alternativel y, 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**  **Capita Waste Disposal Rates Year**  **Waste per capita ton/cap/yr**  1950 0.63 1951 0.63 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 0.681969 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 0.82 1991 0.76 1992 0.74 1993 0.76 1994 0.75 1995 0.70 1996 0.68 1997 0.69 1998 0.751999 0.75

2000 0.80 2001 0.91 2002 1.02 2003 1.02 2004 1.01 2005 0.98 2006 0.95 2007 0.95 2008 0.95 2009 and all later ye ars 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 ty pe 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 or alternative final cover (as approved b y the relevant agency) and/or geomembrane cover sy stem and active gas collection CE5: 95%.

**Weighted average collection efficiency for landfills:** Option 1: Area weighted average collection efficiency for landfills CEave1 = (A2*CE2 + A3*CE3 + A4*CE4 + A5*CE5) / (A2 + A3 + A4 + A5). Option 2: Volume weighted average collection efficiency for landfills , where D2, D3, D4 and D5 are the waste depths for areas A2, A3, A4 and A5 , respectively , as described above. CEave1 = (A2 *D2 *CE2 + A3 *D3 *CE3 + A4 *D4 *CE4 + A5 *D5 *CE5) / (A2 *D2 + A3 *D3 + A4 *D4 + A5 *D5 ).**Table HH -**  **4 to Subpart HH of Part 98**

**— Landfill Methane Oxidation Fractions** 

**Under these conditions: Use**  **this landfill**  **methane oxidation**  **fraction: I. For all reporting years prior to the 2013 reporting year**  C1: For all landfills regardless of cover typ e or methane flux 0.10 **II. For the 2013 reporting year and all subsequent years** C2: For landfills that have an alternative final cover (approved b y the relevant agency) and/or a geomembrane (s ynthetic) cover with less than 12 inches of cover soil for greater than 50% of the landfill area containing waste 0.0

C3: For land fills that do not meet the conditions in C2 above and for which you elect not to determine methane flux , or for landfills with passive vents/passive flares that service greater than 50% of the landfill area containing waste, or for landfills with only passive vents/passive flares or active venting 0.10

C4: For landfills that do not meet the conditions in C2 above and that do not have intermediate or interim covera for greater than 50% of the landfill area containing waste 0.10

C5: For landfills that have intermediate or interim covera for greater than 50% of the landfill area containing waste and for which the methane flux rateb is less than 10 grams per square meter per day (g/m 2 /d) 0.35

C6: For landfills that have intermediate or interim covera for greater than 50% of the landfill area containing waste and for which the methane flux rate b is 10 to 70 g/m 2 /d 0.25

C7: For landfills that have intermediate or interim covera for greater than 50% of the landfill area containing waste and for which the methane flux rate b is greater than 70 g/m 2 /d 0.10

aWhere a landfill is located in a state that does not have an intermediate or interim cover requirement, the landfill must have soil cover of 12 inches or greater in order to use an oxidation fraction of 0.25 or 0.35.
b Methane flux rate (in grams per square me ter 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:Where:

MF = Methane flux rate from the landfill in the reporting ye ar (grams per square meter per day ,

g/m 2 /d). K = unit conversion factor = 10 6 /365 (g/metric ton per day s/ ye ar) or 10 6 /366 for a leap year. SArea = The surface area of the landfill containing waste at the beginning of the reporting ye ar (square meters, m 2 ). G CH4 = Modeled methane generat ion 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 ye ar from Equation HH

- 1 of this subpart or Equation TT

- 1 of this part, as applicable, and the quantity

of recovered CH 4 from Equation HH

- 4 of this subpart (metric tons CH 4 ). CE = Collection efficie ncy estimated at landfill, taking into account s ys tem coverage, operation, and cover s ys tem materials from Table HH

- 3 of this subpart. If area b y soil cover t ypeinformation is not available, use default value of 0.75 (CE4 in table HH

- 3 of this subpart) fo r all areas under active influence of the collection sy stem. N = Number of landfill gas measurement locations (associated with a destruction device or gas

sent off

- site). If a single monitoring location is used to monitor volumetric flow and CH 4 concentrat ion 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 nth measurement location (metric tons). f Rec,n = Fraction of hours the recovery s ys tem associated with the nth measurement location was operating (annual operating hours/8760 hours per year or annual operating hours/8784 hours per ye ar for a leap year).