Cal. Code Regs. Tit. 17, div. 3, ch. 1, subch. 10, art. 4, subart. 6, app I
1.0 Calculate Heat Input Capacity
Heat Input Capacity (MMBtu/hr) = Methane Gas Generation (scfm) x 60 minutes/1 hour x Collection Efficiency x GHV x 1 MMBtu/1,000,000 Btu
Where:
Collection Efficiency = the landfill gas collection efficiency in percent (%), which is 75 percent.
GHV (Gross Heating Value) = Gross heating value of methane, which is 1,012 in units of British thermal units per standard cubic feet, or Btu/scf; source: http://epa.gov/lmop/res/converter.htm).
2.0 Methane Gas Generation: CH4 Generation is calculated using the following equation:
CH4 Generation (Mg of CH4) = {ANDOCyear-start x [1-e-[k]] - ANDOCdeposited-last year x [1/k x (e-[k x (1-M/12)] - e-[k]) - (M/12) x e-[k]] + ANDOCdeposited-same year x [1-((1/k) x (1-e-[k x (1-M/12)] + (M/12))]} x FCH4
Where:
CH4 Generation = CH4 generated in the inventory year in question (Mg of CH4) using the Mathematically Exact First-Order Decay Model provided in the 2006 Intergovernmental Panel on Climate Change (IPCC) Guidelines for National Greenhouse Gas Inventories, Chapter 3 (Source: http://www.ipcc-nggip.iges.or.jp/public/2006gl/pdf/5_Volume5/V5_3_Ch3_SWDS.pdf).
FCH4 = Fraction of decomposing carbon converted into CH4 (Default = 0.5)
ANDOCyear-start = ANDOC in place at the beginning of the inventory year in question
ANDOCdeposited-last year = ANDOC deposited during the previous inventory year
ANDOCdeposited-same year = ANDOC deposited during the inventory year in question
3.0 To Convert Methane Generated from Mg of CH4 to SCFM
CH4 Gas Generated (scfm) = CH4 Generation (Mg/year) x 1 year/ 525,600 minutes x 1,000,000 g/Mg x 1 mole CH4/16.04246 g CH4 x 0.83662 SCF/mole landfill gas
4.0 Define ANDOC%
ANDOC% = [SUMMATION] WIPFRACi x TDOCi x DANFi
Where:
WIPFRACi = Fraction of the ith component in the waste-in-place
TDOCi = Total Degradable Organic Carbon fraction of the ith waste component (Mg of that component/Mg of Total waste-in-place
DANFi =Decomposable Anaerobic Fraction of the ith waste component, that fraction capable of decomposition in anaerobic conditions (Mg of decomposable carbon for that component/Mg TDOCi for that component)
5.0 Define ANDOC
ANDOC = WIP (Tons) x 0.9072 (Mg/Ton) x ANDOC%
Where:
ANDOC = Anaerobically Degradable Organic Carbon, carbon that is capable of decomposition in an anaerobic environment (Mg of carbon)
WIP = Waste-in-Place estimate of all the landfilled waste (wet weight) as reported to the CIWMB (tons)
6.0 Calculate ANDOCyear-end
ANDOCyear-end = ANDOCyear-start x e-[k] +
ANDOCdeposited-last year x [1/k x (e-[k x (1-M/12)] - e-[k]) - (M/12) x e-[k]] + ANDOCdeposited-same year x [(1/k) x (1-e-[k x (1-M/12)] + (M/12)]
Where:
ANDOCyear-end = ANDOC remaining undecomposed at the end of the inventory year in question
ANDOCyear-start = ANDOC in place at the beginning of the inventory year in question
ANDOCdeposited-last year = ANDOC deposited during the previous inventory year
ANDOCdeposited-same year = ANDOC deposited during the inventory year in question
M = Assumed delay before newly deposited waste begins to undergo anaerobic decomposition (Months, Default = 6)
k = Assumed rate constant for anaerobic decomposition; k = ln2/half-life (years); half-life is the number of years required for half of the original mass of carbon to degrade
The following values for the assumed rate constant for anaerobic decomposition (or "k") must be used:
Table 1. Average Rainfall and k Values
Average Rainfall (Inches/Year) | k Value |
| <20 | 0.020 |
| 20-40 | 0.038 |
| >40 | 0.057 |
Source: U.S. EPA
http//www.ncgc.nrcs.usda.gov/products/datasets/climate/data/precipitation-state/.
The following waste characterization default values shown in Tables 1A, 1B, 2, and 3 in addition to the model equations must be used in estimating the methane generation potential for a MSW landfill:
Table 1A
Waste Type (%) by Year | |||||
Waste Type | Up to 1964 | 1965-1974 | 1975-1984 | 1985-1992 | 1993-1995 |
| Newspaper | 6.4% | 6.4% | 5.9% | 4.8% | 3.9% |
| Office Paper | 10.7% | 11.3% | 12.0% | 13.1% | 15.0% |
| Corrugated Boxes | 10.8% | 13.5% | 11.5% | 10.5% | 10.3% |
| Coated Paper | 2.2% | 2.0% | 2.4% | 2.1% | 1.8% |
| Food | 14.8% | 11.3% | 9.5% | 12.1% | 13.4% |
| Grass | 12.1% | 10.3% | 10.1% | 9.0% | 6.6% |
| Leaves | 6.1% | 5.1% | 5.0% | 4.5% | 3.3% |
| Branches | 6.1% | 5.1% | 5.0% | 4.5% | 3.3% |
| Lumber | 3.7% | 3.3% | 5.1% | 7.0% | 7.3% |
| Textiles | 2.1% | 1.8% | 1.7% | 3.3% | 4.5% |
| Diapers | 0.1% | 0.3% | 1.4% | 1.6% | 1.9% |
| Construction/Demolition | 2.6% | 2.5% | 3.5% | 3.9% | 4.5% |
| Medical Waste | 0.0% | 0.0% | 0.0% | 0.0% | 0.0% |
| Sludge/Manure | 0.0% | 0.0% | 0.0% | 0.0% | 0.0% |
| Source: US EPA Municipal Solid Waste publication: http://www.epa.gov/msw/pubs/03data.pdf. | |||||
Table 1B
Waste Type (%) by Year | ||
| Waste Type | 1996-20021 | 2003-present2 |
| Newspaper | 4.3% | 2.2% |
| Office Paper | 4.4% | 2.0% |
| Corrugated Boxes | 4.6% | 5.7% |
| Coated Paper | 16.9% | 11.1% |
| Food | 15.7% | 14.6% |
| Grass | 5.3% | 2.8% |
| Leaves | 2.6% | 1.4% |
| Branches | 2.4% | 2.6% |
| Lumber | 4.9% | 9.6% |
| Textiles | 2.1% | 4.4% |
| Diapers | 6.9% | 4.4% |
| Construction/Demolition | 6.7% | 12.1% |
| Medical Waste | 0.0% | 0.0% |
| Sludge/Manure | 0.1% | 0.1% |
| Source: | ||
1 CIWMB Statewide Waste Characterization Study (1999).
2 CIWMB Statewide Waste Characterization Study (2004).
Table 2
| Waste Type | TDOC | Source |
| Newspaper | 46.5% | EPA |
| Office Paper | 39.8% | EPA |
| Corrugated Boxes | 40.5% | EPA |
| Coated Paper | 40.5% | EPA |
| Food | 11.7% | EPA |
| Grass | 19.2% | EPA |
| Leaves | 47.8% | EPA |
| Branches | 27.9% | EPA |
| Lumber | 43.0% | IPCC |
| Textiles | 24.0% | IPCC |
| Diapers | 24.0% | IPCC |
| Construction/Demolition | 4.0% | IPCC |
| Medical Waste | 15.0% | IPCC |
| Sludge/Manure | 5.0% | IPCC |
| Sources |
EPA Solid Waste Management and Greenhouse Gasses: A Life-Cycle Assessment of Emissions and Sinks, Exhibits 7-2, 7-3 (May 2002).
IPCC Guidelines for National Greenhouse Gas Inventories, Chapter 2, Table 2.4, 2.5 and 2.6 (2006).
Table 3
| Waste Type | DANF | Source |
| Newspaper | 16.1% | EPA |
| Office Paper | 87.4% | EPA |
| Corrugated Boxes | 38.3% | EPA |
| Coated Paper | 21.0% | EPA |
| Food | 82.8% | EPA |
| Grass | 32.2% | EPA |
| Leaves | 10.0% | EPA |
| Branches | 17.6% | EPA |
| Lumber | 23.3% | CEC |
| Textiles | 50.0% | IPCC |
| Diapers | 50.0% | IPCC |
| Construction/Demolition | 50.0% | IPCC |
| Medical Waste | 50.0% | IPCC |
| Sludge/Manure | 50.0% | IPCC |
| Sources: |
EPA Solid Waste Management and Greenhouse Gasses: A Life-Cycle Assessment of Emissions and Sinks Exhibits 7-2, 7-3 (May 2002).
CEC Inventory of California Greenhouse Gas Emissions and Sinks: 1990-2004 (December 2006).
IPCC Guidelines for National Greenhouse Gas Inventories, Chapter 3, 3.13 (2006).
Cal. Code Regs. Tit. 17, div. 3, ch. 1, subch. 10, art. 4, subart. 6, app I