CGE Training Materials
National Greenhouse Gas Inventories
UNFCCC – NAI GHG Inventory Software
Waste Sector
Practical Aspects and Exercises
 Version 2, April 2012
Consultative Group of Experts (CGE)
Training Materials for National Greenhouse Gas Inventories
Content
a)
Details on use of the UNFCCC-NAI Software to calculate and report GHG emissions
in the waste sector.
b)
Practical exercises (to be solved by the participants after the presentation).
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Background
a)
The decision trees in the IPCC good practice guidance (GPG 2000) are used to choose
a good practice method that suits national circumstances.
b)
The UNFCCC-NAI Software contains, basically, the methods of lesser complexity that
countries can use to prepare their inventories.
c)
However, in principle, the software can be used to report the estimated emissions
independently of the complexity of method used (Tier 2, 3, etc).
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Waste Sector
Sector 6: Waste
Source Categories and Subcategories
Worksheets
6A. CH4 Emissions from Solid Waste Disposal
6-1s1 and 6-1sA to 6-1sC (4)
6B1. CH4 Emissions from Domestic and Commercial Wastewater and 6-2s1 to 6-2s4 (4)
Sludge
6B2. CH4 Emissions From Industrial Wastewater and Sludge Handling 6-3s1 to 6-3s4 (4)
6B2. Indirect Nitrous Oxide emissions from Human Sewage
6-4s1 (1) (*)
6C. Waste Incineration
6-5s1 (1) (**)
(#) Quantity of sheets
Changes in the worksheets with respect to the UNFCCC Software
*
To avoid double counting, a column was included in the UNFCCC–NAI Software for considering
(decrease) the amount of sewage N applied to soils as sewage sludge (Nsew sludge).
**
The UNFCCC–NAI Software includes a worksheet to calculate the emissions of CO2, CH4 and N2O from
waste incineration. Such as worksheet was not included in the IPCC software and the Revised 1996 IPCC
Guidelines.
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CH4 Emissions from Solid Waste Disposal Sites (SWDSs)
SECTOR: WASTE (1)
UNFCCC MAIN
NAI
CATEGORIES
SOFTWARE
Tier 1:
Worksheets
6-1s1 and 6-1A
6A. CH4
Emissions from to 6-1C
Solid Waste
Disposal
Remarks
- The IPCC Guidelines do not classify methodological tiers for the Waste
sector. Methodological tiers 1 and 2 are defined in the GPG 2000. The two
methods can yield quite different estimates.
Tier 1. Default Method
- Based on the assumption that all potential CH4 is released in the year the
waste is disposed. If the amount or composition of waste change rapidly over
time this method will not provide an accurate trend.
- If the activity data are available then there is not difficulty in using the Tier 1
Method and the software to estimate CH4 emissions, but it is recommended to
use this method only as a last alternative until the IPCC 2006 Guidelines
eventually be used.
- Most of the factors required to apply this method can usually be obtained or
estimated. Default values can also be applied.
- It is required to know the population whose waste goes to SWDSs (total or
urban), the MSW generation rate (country specific or default), and the fraction
of MSW disposed of in SWDSs (country-specific or default). The parameter Lo
(methane generation potential) is more difficult because it requires that the
degradable organic component (DOC) be known, which is based on the
composition of the waste.
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CH4 Emissions from Solid Waste Disposal Sites (SWDSs) (cont.)
SECTOR: WASTE (2)
MAIN
UNFCCC CATEGORIES
NAI
SOFTWARE
Tier 1:
Worksheets
6A. CH4
6-1s1 and 6-1A
Emissions from to 6-1C
Solid Waste
Disposal
Remarks
Tier 1. Default Method.
When applying this method keep in mind that:
1 - If a significant quantity of organic industrial solid waste is disposed of to
SWDSs, care should be taken to determine the per capita solid waste generation
rate and DOC.
2 - DOCf: The default value provided in the IPCC Guidelines is appropriate if
lignin carbon is excluded. If lignin carbon is included a value in the range 0.5–
0.6 should be used.
3 - Oxidation factor is assumed as zero except for well managed sites where 0.1
is reasonable.
4 - CO2 emissions are reported if combustion is used as a management practice
at solid waste disposal sites (CO2 emissions from non-biogenic sources are
included in the totals). It is necessary to know the composition of the material
that is combusted.
5 - Sludge from wastewater handling if often disposed of to SWDSs. Emissions
from this sludge should be included under this category.
6 - Add notes in the documentation box of the worksheet clarifying whether
SWDSs were included and if any industrial sites were included.
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CH4 Emissions from Solid Waste Disposal Sites (SWDSs) (cont.)
SECTOR: WASTE (3)
MAIN
UNFCCC -NAI
CATEGORIES
SOFTWARE
Tier 1:
Worksheets
6A. CH4
Emissions from
Solid Waste
Disposal
Tier 2
Methods
First Order
Decay
(FOD)
Method
Remarks
Tier 2.
- It is good practice to use the FOD method, if possible, because it more
accurately reflects the emission trend.
- Produces a time-dependent emission profile that better reflects the true
pattern of the degradation process.
- Requires data on current as well as historic waste quantities, composition
and disposal practices. It is good practice to estimate this historical data if
such data are unavailable.
- The IPCC Guidelines do not provide default values or methods for the
estimation of some key parameters. However, the main difficulties of this
method are also related with Lo besides the historical behavior of some
variables. Other parameters can be obtained from recommended interval.
- With the UNFCCC–NAI software it is impossible to calculate the methane
emissions, in this source category, using the FOD method (Tier 2).
Suggestion: If that approach is used instead of the default method, then: 1)
make the calculations outside of the software, 2) incorporate the results
manually in the Sectoral Table and the Tables of Summary of the Inventory,
3) add a note to the documentation boxes of Tables 6-1s1 and
6-1sA to 6-1B clarifying the method used and results obtained. Provide
detailed information in the NIR.
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CH4 Emissions from Domestic and Commercial Wastewater and Sludge Handling
SECTOR: WASTE (4)
MAIN
UNFCCC –
CATEGORIES
NAI
SOFTWARE
Tier 1:
Worksheets
6B1. CH4 Emissions 6-2s1 to 6-2s4
from Domestic and
The IPCC
Commercial
Guidelines
Wastewater and
describe a
Sludge
single method
for calculating
CH4 emissions.
Remarks
- If activity data are available then there is no difficulty in using the
software to estimate emissions.
- Emissions are a function of the amount of waste generated and an EF.
Any CH4 that is recovered and flared or used for energy should be
subtracted from total emissions.
- Good practice is to use country-specific data expressed in terms of kg
CH4/kg BOD removed. If country-specific data are not available, a default
value can be used. It is good practice to use a default value of 0.6 kg
CH4/kg BOD.
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CH4 Emissions from Domestic and Commercial Wastewater and Sludge Handling (cont.)
SECTOR: WASTE (4)
MAIN
UNFCCC –
CATEGORIES
NAI
SOFTWARE
Tier 1:
Worksheets
6B1. CH4 Emissions 6-2s1 to 6-2s4
from Domestic and
The IPCC
Commercial
Guidelines
Wastewater and
describe a
Sludge
single method
for calculating
CH4 emissions.
Remarks
Notes:
1 - The IPCC Guidelines provide only one default value of Bo that has to
be applied to both COD and BOD. This is not consistent with the observed
differences between BOD and COD in raw sewage.
2 - If default factors are being used, emissions from wastewater and sludge
can be estimated together.
3 - CH4 emissions from sludge sent to landfills or used in agriculture are
not included in this sector.
4 - Sludge incinerated as part of energy recovery should be included in the
energy sector.
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Exercise 1:
CH4 Emissions from Domestic and Commercial Wastewater and Sludge Handling (I)
Country A: Year: 2000. Worksheets 6-2s1 to 6-2s4
Data
•
The National Statistics Office has provided the information included in the following table.
Population (1000
persons)
Degradable organic
component
Fraction of DOC
removed as sludge
Methane recovered
18 250.5
15 330 kg BOD/1000
persons/yr
0
5 000 tonne
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Exercise 1:
CH4 Emissions from Domestic and Commercial Wastewater and Sludge Handling (II)
Other Data:
•
Use the following values for the calculation:
Collected
(sewered to plant)
Uncollected
Wastewater handling system
Fraction of wastewater treated
by the handling system
Methane conversion factor for
the handling system
Lagoons
0.02
0.8
Not specified
0.05
0.75
Latrines and septic systems
0.3
0.15
(anaerobic deep)
(treated on site)
With regular sediment removal
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Exercise 1:
CH4 Emissions from Domestic and Commercial Wastewater and Sludge Handling (III)
Tasks
Using the UNFCCC-NAI Software:
•
Calculate net CH4 emissions
•
Verify the emissions report in the Sectoral and Summary Tables
•
Fill in Table 8A (Overview Table) for the self evaluation of quality and completeness
•
Print the worksheet used, the Sectoral Summary Table and the Overview Table (8A).
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Exercise 1:
CH4 Emissions from Domestic and Commercial Wastewater and Sludge Handling (IV)
Steps
•
Open the software and select in the waste sector Worksheet 6-2s1 Estimation of Organic
Wastewater and Sludge.
•
Specify in column A that the estimation is for “all country”.
•
Enter population data in Column B, and DOC in column C.
•
Specify the Fraction of DOC removed as sludge. The software calculates the Total
Domestic/Commercial Organic Wastewater.
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Exercise 1:
CH4 Emissions from Domestic and Commercial Wastewater and Sludge Handling (IV)
Steps
•
Go to Worksheet 6-2s2 and specify in column A the Wastewater Handling Systems used in
the country.
•
Enter in column B the Fraction of Wastewater Treated by the Handling Systems and in C the
Methane Conversion Factor. Enter in E the Maximum Methane Producing Capacity (0.6 kg
CH4/kg BOD). The software calculates the EF.
Go to Worksheet 6-2s4 and enter in D the Methane Recovered. The software calculates Net
CH4 emissions.
•
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ESTIMATION OF ORGANIC WASTEWATER
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ESTIMATION OF EMISSION FACTOR
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CH4 EMISSIONS FROM
DOMESTIC AND COMMERCIAL
WASTEWATER HANDLING
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CH4 EMISSIONS FROM DOMESTIC AND COMMERCIAL
WASTEWATER HANDLING IN THE SECTORAL
REPORT TABLE
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CH4 EMISSIONS FROM DOMESTIC AND COMMERCIAL
WASTEWATER HANDLING IN THE SUMMARY
REPORT TABLE
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CH4 Emissions from Industrial Wastewater and Sludge Handling
SECTOR: W
ASTE(5)
M
AIN
UNFCCC- NAI
CATEGORIES
SOFTW
ARE
Tier1:
W
orksheets
6B2. CH4
6-3s1to6-3s4
Emissions From - Themethodis
Industrial
similar totheone
W
astewater and usedfor domestic
SludgeHandling wastewater.
- Thedevelopment
of EFandADis
morecomplex
becausethereare
manytypes of
wastewater and
manydifferent
industries.
Remarks
- If activitydataareavailablethenthereis nodifficultyinusingthesoftwareto
estimateemissions.
If nonational dataareavailable:
- EstimateCH4 for all industries usingexpert judgment or default values for CODdata.
Suggestion:
1. If possible, collect or estimateCODdatafor thethreeor four most important
industrytypeswithtreatment insite(e.g. foodandbeverages, pulpandpaper,
textiles, petrochemicals, etc.).
2. CalculateCH4 emissionsfromindustrial wastewater basedonCODfrommost
important industries.
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CH4 Emissions from Industrial Wastewater and Sludge Handling (cont.)
SECTOR: W
ASTE(5)
M
AIN
UNFCCC- NAI
CATEGORIES
SOFTW
ARE
Tier1:
W
orksheets
6B2. CH4
6-3s1to6-3s4
Emissions From - Themethodis
Industrial
similar totheone
W
astewater and usedfor domestic
SludgeHandling wastewater.
- Thedevelopment
of EFandADis
morecomplex
becausethereare
manytypes of
wastewater and
manydifferent
industries.
Remarks
Notes:
- Typical CODvalues for someindustries providedintheIPCCGuidelines wereupdatedin
GPG2000(Table5.4). Theunits for wastewater generationandCODinthis Tableare
different (but equivalent) tothoseof theworkbookandthesoftware.
- TheEFcalculationinworksheets 6-3s2and6-3s3shouldbemadefor specificindustrial
wastewater sources. Todothis it wouldbenecessarytocopyandinsert theseworksheets
several times andtoassurethenecessarylinks. Another optionis tomakeanaggregated
analysis for eachtypeof W
astewater HandlingSystemusedfor industrytype(or for all the
industries).
- Possibilityof doublecountingemissions duetosomeindustrial wastewater beingreleased
intomunicipal seweragesystems andaccountedunder DomesticandCommercial
W
astewater.
- Possibleoverestimationof CH4 emissions as aresult of theincinerationof sludge.
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Indirect N2O Emissions from Human Sewage
SECTOR: WASTE (6)
MAIN
CATEGORIES
6B2. Indirect
Nitrous Oxide
emissions from
Human Sewage
UNFCCC NAI
SOFTWARE
Tier 1:
Worksheets
6-4s1
Remarks
Default Method
- Method based on per capita protein consumption. This method for
estimating N2O emissions from N in sewage that is discharged into rivers
and/or estuaries is presented in GPG 2000 chapter 4 Agriculture, although
these emissions are reported under the waste sector (Domestic and
Commercial Wastewater).
- Requires knowing the average annual Per Capita Protein consumption in
the country, the Population in the Country, the Fraction of N in Protein and
the EF (EF6). Country-specific and default data may be used.
Note: Country-specific values of EF6 must be used with great caution
because of the complexity of this emission pathway.
- The software can be used directly for the estimation.
- To avoid double counting, a column for considering (decrease) the amount
of sewage N applied to soils as sewage sludge (Nsew sludge) was included
in the software.
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Emissions from Waste Incineration
SECTOR: WASTE (7)
MAIN
UNFCCC - NAI
CATEGORIES
SOFTWARE
Tier 1: Worksheets
6C. Waste
Incineration
- This source category
was not included in the
Workbook and the IPCC
Software, therefore there
are no Worksheets.
- The Reference section
of the IPCC Guidelines
Manual describes a
general approach and
provides references to
methods available for
some of the gases.
- The UNFCCC–NAI
Software includes a
worksheet to calculate
the emissions of CO2,
CH4 and N2O from waste
incineration. The IPCC
Guidelines do not
include worksheets for
this source category.
Remarks
Emissions from this source category can be estimated using the UNFCCC–NAI
software.
- GPG2000 provides approaches to determine the emissions of CO2 and N2O
(emissions of CH4 are not likely to be significant).
- The method requires knowing waste incinerated, EF and the burn out efficiency of
combustion. Country-specific and default values may be used.
- The most accurate estimates can be developed by determining the emissions for each
type of waste (e.g. municipal solid waste, sewage sludge, clinical waste and hazardous
waste).
Notes:
1 - Only CO2 emissions resulting from the incineration of carbon in waste of fossil
origin (e.g. plastics, certain textiles, rubber, liquid solvents and waste oil) should be
included.
2 - CO2 emissions from combustion used as a management practice at SWDSs are to be
included under Solid Waste Disposal.
3 - Emissions without energy recovery have to be reported in the waste sector, whereas
emissions with energy recovery should be reported in the energy sector.
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Emissions from Waste Incineration and Open Burning of Waste
SECTOR: WASTE (7)
UNFCCC - NAI
MAIN
SOFTWARE
CATEGORIES
Tier 1: Worksheets
6C. Waste
Incineration by
Open Burning of
waste
- There is methodology
to calculate the
emissions of CO2, CH4
and N2O from waste
incineration. The IPCC
Guidelines do not
include worksheets for
this source category.
Remarks
Emissions from this source category can be estimated using independent methods
including the use as an advanced Tier of IPCC 2006 guidelines:
 Page 5-16 contains suggestions for activity data .
 Pages 5-20 and 5-22 provide EF for CH4 and N2O.
For CO2 the oxidation factor needs to be calculated locally but is below 100%.
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NEW WORSHEET 6-5S1 INCLUDED IN THE UNFCCC–NAI SOFTWARE
FOR CALCULATING EMISSIONS FROM WASTE INCINERATION
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Exercise for self-evaluation 1: CH4 from Solid Waste Disposal on Land (I)
Country A: Year: 2000.
Data

The Environment Ministry provided data on solid waste disposal in the country during the
year 2000. It also provided results from studies carried out on solid waste characterization.

Determine the CH4 emissions from the disposition of solid waste on land using the UNFCCCNAI Software.

Verify the results obtained in the Sectoral Report Table and the Summary Tables of the
Inventory.
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Exercise for self-evaluation 1: CH4 from Solid Waste Disposal on Land (II)
COUNTRY A: YEAR 2000. DATA RELATED WITH SOLID WASTES DISPOSAL
Urban population of the country
8 666 744 persons
MSW generation rate
0.68 kg/capita/day
Fraction of MSW disposed to SWDSs
1
Proportion of waste for each type of SWDSs
• Managed
0.7
• Unmanaged-shallow
0.3
Fraction of DOC in MSW
0.18
Recovered methane per year (Gg)
0
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Exercise for self-evaluation 1: CH4 from Solid Waste Disposal on Land (III)
RESULTS
CH4 emissions from solid waste disposal on land
113.73 Gg CH4
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Thank you
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