40 C.F.R. § 98.343
Where:
GCH4 = Modeled methane generation rate in reporting year T (metric tons CH4).
x = Year in which waste was disposed.
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 year. If there is active aeration of waste within the landfill during the reporting year, use either the default value of 1 or select an alternative value no 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)].
DOCF = Fraction of DOC dissimilated (fraction). Use the default value of 0.5.
F = Fraction by volume of CH4 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).
where:
WX = Quantity of waste placed in the landfill in year x (metric tons, wet basis).
POPX = 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 (metric tons per capita per year, wet basis; tons/cap/yr).
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 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 years as the default operating life of the landfill.
where:
R = Annual quantity of recovered CH4 (metric tons CH4).
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 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 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)n and (C)n are both measured on a dry basis or if both are measured on a wet basis; (KMC)n = [1-(fH2O)n] when (V)n is measured on a wet basis and (C)n is measured on a dry basis; and (KMC)n = 1/[1-(fH2O)n] when (V)n is measured on a dry basis and (C)n is measured on a wet basis.
(fH2O)n = Average moisture content of landfill gas during the measurement period, volumetric basis (cubic feet water per cubic feet landfill gas)
(CCH4)n = Average CH4 concentration of landfill gas for the measurement period (volume %).
0.0423 = Density of CH4 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).
Where:
MG = Methane generation, adjusted for oxidation, from the landfill in the reporting year (metric tons CH4).
GCH4 = Modeled methane generation rate in reporting year from Equation HH-1 of this section (metric tons CH4).
OX = Oxidation fraction. Use the appropriate oxidation fraction default value from Table HH-4 of this subpart.
Where:
Emissions = Methane emissions from the landfill in the reporting year (metric tons CH4).
GCH4 = Modeled methane generation rate in reporting year from Equation HH-1 of this section or the quantity of recovered CH4 from Equation HH-4 of this section, whichever is greater (metric tons CH4).
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 CH4 concentration of the recovered gas sent to one or multiple destruction devices, then N = 1.
Rn = Quantity of recovered CH4 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.
DEn = 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 CH4 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 DEn as the arithmetic average of the DE values determined for each destruction device associated with that measurement location.
fDest,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 fDest,n= 1. If the volumetric flow and CH4 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 fDest,n as the arithmetic average of the fDest values determined for each destruction device associated with that measurement location.
Where:
MG = Methane generation, adjusted for oxidation, from the landfill in the reporting year (metric tons CH4).
Emissions = Methane emissions from the landfill in the reporting year (metric tons CH4).
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 CH4 concentration of the recovered gas sent to one or multiple destruction devices, then N = 1.
Rn = Quantity of recovered CH4 from Equation HH-4 of this section for the nth measurement location (metric tons CH4).
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.
fRec,n = Fraction of hours the recovery system associated with the nth measurement location was operating (annual operating hours/8760 hours per year or annual operating hours/8784 hours per year for a leap year).
OX = Oxidation fraction. Use appropriate oxidation fraction default value from Table HH-4 of this subpart.
DEn = 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 CH4 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 DEn as the arithmetic average of the DE values determined for each destruction device associated with that measurement location.
fDest,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 fDest,n= 1. If the volumetric flow and CH4 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 fDest,n as the arithmetic average of the fDest values determined for each destruction device associated with that measurement location.
40 C.F.R. §98.343