Subpart AA Emissions Information for Units NOT Monitored CEMS
Note: The Cal e-GGRT help system includes general instruction on using the California GHG reporting tool. However, the help system may not explain differences between California and U.S. EPA reporting requirements. Please refer to the ARB reporting website for California-specific reporting requirements and additional help.


This page provides a step-by-step description of how to enter Subpart AA emissions data.

Note: Emissions information for Subpart AA depends upon the type of unit.

  • Chemical Recovery Furnace requires you to report emissions using Equation AA-1
  • Chemical Recovery Combustion Unit requires you to report emissions using Equation AA-1 and AA-2
  • Pulp Mill Lime Kiln requires you to report emissions using Equations from Subpart C

Adding or Updating Emissions Information for a Chemical Recovery Furnace or Combustion Unit

To add or update Subpart AA emissions information for a Chemical Recovery Furnace or Chemical Recovery Combustion Unit, find the unit or furnace for which you would like to enter emissions information in the UNIT AND FURNACE SUMMARY table on the Subpart AA Overview page, and click OPEN.

Click image to expand

Step 1: Equations AA-1 / AA-2 Summary and Result

For each chemical recovery furnace, Subpart AA requires the following emissions information:

  • The annual biogenic CO2, CH4 and N2O process emissions

To calculate these values download the applicable spreadsheet by clicking the link titled "Use Subpart AA-1 equation spreadsheet to calculate". Fill in the spreadsheet using the instructions in the spreadsheet. After completing the spreadsheet, copy the values of CO2, CH4 and N2O calculated by the spreadsheet to this page in the boxes next to "Result (CO2 from biomass)", "Result (CH4 from biomass)" and "Result (N2O from biomass)".

The Equation AA-1 Summary is presented on this page. You can hover over an element in the equation to reveal a definition of that element.

For each chemical recovery combustion unit, Subpart AA requires the following emissions information:

  • The annual biogenic CO2, CH4 and N2O process emissions

To calculate these values download the spreadsheets by clicking the links titled "Use AA-1 spreadsheet to calculate" and "Use AA-2 spreadsheet to calculate". Fill in the spreadsheets using the instructions in the spreadsheets. After completing the spreadsheets, copy the values of CO2, CH4 and N2O calculated by the spreadsheets to this page in the boxes next to "Result (Biogenic CO2)", "Result (CH4 from biomass)" and "Result (N2O from biomass)".

The Equation AA-1 / AA-2 Summary is presented on this page. You can hover over an element in the equation to reveal a definition of that element.

Step 2: Upload Equation Spreadsheet

When you have finished entering emission results and substitute data, save your AA-1 equation spreadsheet to your computer. Click UPLOAD and select your saved AA-1 equation spreadsheet for upload. Your file path will appear on the screen to the left of the BROWSE button. Next, click UPLOAD and your uploaded file will appear under the heading "Uploaded File Name".

Step 3: Basis and Substitute value

For each unit or furnace within your facility, Subpart AA requires you to report the following data:

  • The basis for annual mass. Select from:
    • TAPPI method
    • On-line metering/measuring system
  • Indicate if a substitute value was used.

Note: Steps 3-4 of this section do not apply for spent pulping liquor (the primary fuel for chemical recovery combustion units and recovery furnaces) or other biogenic fuel types. If spent pulping liquor and/or other biogenic fuels are the only fuel combusted by this unit or furnace, skip to Step 5.

Step 4: Identify Fuels Combusted by this Unit (if applicable)

To add a fuel combusted by this unit, click the link titled "ADD a Fuel" below the FUEL EMISSIONS INFORMATION table.

To edit a fuel, click on the edit icon or the Name/ID link, which is the first column in the FUEL EMISSIONS INFORMATION table.

To delete a fuel, click on the delete icon, which is the last column in the FUEL EMISSIONS INFORMATION table.

Click image to expand

On the Add Fuel screen, select a fuel combusted by this unit.

When finished, click SAVE

Click image to expand

For each fuel combusted by the unit, Subpart AA requires the following fuel information

  • Calculation methodology start date and end date, for each fuel type
  • Calculation methodology used for the emissions calculation period specified, for each fuel type:
    • Tier 1/Equation C-1: Annual fuel combusted, default heating value, and default CO2 emission factor
    • Tier 1/Equation C-1a: Annual natural gas usage from billing records (therms) and default CO2 emission factor
    • Tier 1/Equation C-1b: Annual natural gas usage from billing records (mmBtu) and default CO2 emission factor
    • Tier 2/Equation C-2a: Annual fuel combusted, measured heating value, and default CO2 emission factor
    • Tier 2/Equation C-2c: Steam generation, ratio of maximum rated heat input capacity to design rated steam output capacity, and default CO2 emission factor (for MSW and solid fuels listed in Table C-1))
    • Tier 3/Equation C-3: Annual mass of solid fuel combusted and average carbon content of the solid fuel
    • Tier 3/Equation C-4: Annual mass of liquid fuel combusted and average carbon content of the liquid fuel
    • Tier 3/Equation C-5: Annual volume of gaseous fuel combusted, average carbon content of the gaseous fuel, and average molecular weight of the gaseous fuel

When you have entered the required information, click SAVE

Repeat this step until all fuels combusted by this unit have been added and identified.

Click image to expand

Step 5: Enter Required Emissions Information for Each Fuel (if applicable)

To select a fuel combusted by this unit for which to enter emissions information, find the fuel in the FUEL EMISSIONS INFORMATION table and click OPEN.

For each fuel type (including biomass fuel(s)) for which you have elected to use a Tier 1 (Equation C-1, C-1a, or C-1b) methodology, you are required to report the following information by fuel type:

  • The total annual CO2 mass emissions derived from Equation C-1, Equation C-1a, or Equation C-1b in metric tons CO2 [98.36(b)(8)(i), 98.36(c)(1)(vi), 98.36(c)(3)(vii)]

  • The total annual CH4 mass emissions derived from Equation C-8, Equation C-8a, or Equation C-8b in metric tons CH4 and in metric tons CO2e (for Table C-2 fuels only) [98.36(b)(8)(i), 98.36(c)(1)(vi), 98.36(c)(3)(vii)]

  • The total annual N2O mass emissions derived from Equation C-8, Equation C-8a, or Equation C-8b in metric tons N2O and in metric tons CO2e (for Table C-2 fuels only) [98.36(b)(8)(i), 98.36(c)(1)(vi), 98.36(c)(3)(vii)]

For each fuel type (including biomass fuel(s)) for which you have elected to use the Tier 2 (Equation C-2a) methodology, you are required to report the following information by fuel type:

  • The total annual CO2 mass emissions derived from Equation C-2a in metric tons CO2 [98.36(b)(8)(i), 98.36(c)(1)(vi), 98.36(c)(3)(vii)]

  • The total annual CH4 mass emissions derived from Equation C-9a in metric tons CH4 and in metric tons CO2e (for Table C-2 fuels only) [98.36(b)(8)(i), 98.36(c)(1)(vi), 98.36(c)(3)(vii)]

  • The total annual N2O mass emissions derived from Equation C-9a in metric tons N2O and in metric tons CO2e (for Table C-2 fuels only) [98.36(b)(8)(i), 98.36(c)(1)(vi), 98.36(c)(3)(vii)]

  • Identification of each month for which HHVs were calculated using one or more substitute data values [98.36(e)(2)(ii)(C)]

  • The frequency of the HHV determinations [98.36(e)(2)(ii)(B)]

    • Hourly
    • Daily
    • Weekly
    • Monthly
    • Semiannually
    • Quarterly
    • Once per fuel lot
    • Upon addition of oil to the storage tank
    • Other (specify)

For each fuel type (including biomass fuel(s)) for which you have elected to use the Tier 2 (Equation C-2c) methodology, you are required to report the following information by fuel type:

  • The total annual CO2 mass emissions derived from Equation C-2c in metric tons CO2 [98.36(b)(8)(i), 98.36(c)(1)(vi), 98.36(c)(3)(vii)]

  • The total annual CH4 mass emissions derived from Equation C-9b in metric tons CH4 and in metric tons CO2e (for Table C-2 fuels only) [98.36(b)(8)(i), 98.36(c)(1)(vi), 98.36(c)(3)(vii)]

  • The total annual N2O mass emissions derived from Equation C-9b in metric tons N2O and in metric tons CO2e (for Table C-2 fuels only) [98.36(b)(8)(i), 98.36(c)(1)(vi), 98.36(c)(3)(vii)]

For each fuel type (including biomass fuel(s)) for which you have elected to use a Tier 3 (Equation C-3, C-4, or C-5) methodology, you are required to report the following information by fuel type:

  • The total annual CO2 mass emissions derived from Equation C-3 for solid fuels, Equation C-4 for liquid fuels, or Equation C-5 for gaseous fuels in metric tons CO2 [98.36(b)(8)(i), 98.36(c)(1)(vi), 98.36(c)(3)(vii)]

  • The total annual CH4 mass emissions derived from Equation C-8 in metric tons CH4 and in metric tons CO2e (for Table C-2 fuels only) [98.36(b)(8)(i), 98.36(c)(1)(vi), 98.36(c)(3)(vii)]

  • The total annual N2O mass emissions derived from Equation C-8 in metric tons N2O and in metric tons CO2e (for Table C-2 fuels only) [98.36(b)(8)(i), 98.36(c)(1)(vi), 98.36(c)(3)(vii)]

  • The total number of valid carbon content determinations [98.36(e)(2)(iv)(D)]

  • The total number of carbon content substitute data values [98.36(e)(2)(iv)(E)]

  • The frequency of carbon content determinations [98.36(e)(2)(iv)(B)]

    • Hourly
    • Daily
    • Weekly
    • Monthly
    • Semiannually
    • Quarterly
    • Once per fuel lot
    • Upon addition of oil to the storage tank
    • Other (specify)
  • The total number of operating hours in the reporting year for which missing data substitution was used for fuel usage [98.3(c)(8)]

For each gaseous fuel at each configuration for which you have elected to use the Tier 3 (Equation C-5) methodology, you are also required to report the following additional information:

  • Total number of valid molecular weight determinations [98.36(e)(2)(iv)(D)]

  • Total number of molecular weight substitute data values [98.36(e)(2)(iv)(E)]

  • Frequency of molecular weight determinations [98.36(e)(2)(iv)(B)]

    • Hourly
    • Daily
    • Weekly
    • Monthly
    • Semiannually
    • Quarterly
    • Other (specify)

Use the red-bordered text boxes to enter the required emissions information.

To calculate the emissions you have the option of using your own resources or alternatively you may use the following tool and set of instructions:

  • Download the spreadsheet tool by clicking the link below one of the red-bordered text boxes labeled "Use Tier X spreadsheet to calculate"
  • Fill in the spreadsheet completely using the instructions provided in the tool
  • After completing the spreadsheet, copy the values calculated by the spreadsheet to the red-bordered text boxes on this page

When you have finished entering emission results for the unit, click SAVE.

Repeat this step until emissions information has been entered for each fuel combusted by the unit.

Click image to expand

Step 6: Save Your Data

When you have finished entering emission results and substitute data, click SAVE.

After you save the data on this page, the next time you open the page, the calculator on the top of the page will display the CO2, CH4, and N2O process emissions, rounded to the nearest metric ton. The value displayed is for informational purposes only.

When CO2, CH4 and N2O process emissions have been entered the Status column on the Unit and Furnace Summary will show "Complete" and the background color for that furnace will show as green.

Adding or Updating Emissions for unit type Pulp Mill Lime Kiln

To add or update Subpart AA emissions for unit type Pulp Mill Lime Kiln, find the kiln for which you would like to enter emissions information in the UNIT AND FURNACE SUMMARY table on the Subpart AA Overview page, and click OPEN.

Click image to expand

Step 1: Identify Fuels Combusted by this Unit

To add a fuel combusted by this unit, click the link titled "ADD a Fuel" below the FUEL EMISSIONS INFORMATION table.

To edit a fuel, click on the edit icon or the Name/ID link, which is the first column in the FUEL EMISSIONS INFORMATION table.

To delete a fuel, click on the delete icon, which is the last column in the FUEL EMISSIONS INFORMATION table.

Click image to expand

On the Add Fuel screen, select a fuel combusted by this unit.

When finished, click SAVE

Click image to expand

For each fuel combusted by the unit, Subpart AA requires the following fuel information

  • Calculation methodology start date and end date, for each fuel type
  • Calculation methodology used for the emissions calculation period specified, for each fuel type:
    • Tier 1/Equation C-1: Annual fuel combusted, default heating value, and default CO2 emission factor
    • Tier 1/Equation C-1a: Annual natural gas usage from billing records (therms) and default CO2 emission factor
    • Tier 1/Equation C-1b: Annual natural gas usage from billing records (mmBtu) and default CO2 emission factor
    • Tier 2/Equation C-2a: Annual fuel combusted, measured heating value, and default CO2 emission factor
    • Tier 2/Equation C-2c: Steam generation, ratio of maximum rated heat input capacity to design rated steam output capacity, and default CO2 emission factor (for MSW and solid fuels listed in Table C-1))
    • Tier 3/Equation C-3: Annual mass of solid fuel combusted and average carbon content of the solid fuel
    • Tier 3/Equation C-4: Annual mass of liquid fuel combusted and average carbon content of the liquid fuel
    • Tier 3/Equation C-5: Annual volume of gaseous fuel combusted, average carbon content of the gaseous fuel, and average molecular weight of the gaseous fuel

When you have entered the required information, click SAVE

Repeat this step until all fuels combusted by this unit have been added and identified.

Click image to expand

Step 2: Enter Required Emissions Information for Each Fuel

To select a fuel combusted by this unit for which to enter emissions information, find the fuel in the FUEL EMISSIONS INFORMATION table and click OPEN.

For each fuel type (not including biomass fuel(s)) for which you have elected to use a Tier 1 (Equation C-1, C-1a, or C-1b) methodology, you are required to report the following information by fuel type:

  • The total annual CO2 mass emissions derived from Equation C-1, Equation C-1a, or Equation C-1b in metric tons CO2 [98.36(b)(8)(i), 98.36(c)(1)(vi), 98.36(c)(3)(vii)]

  • The total annual CH4 mass emissions derived from Equation C-8, Equation C-8a, or Equation C-8b in metric tons CH4 and in metric tons CO2e (for Table AA-2 fuels only) [98.36(b)(8)(i), 98.36(c)(1)(vi), 98.36(c)(3)(vii), 98.273(c)(2)]

  • The total annual N2O mass emissions derived from Equation C-8, Equation C-8a, or Equation C-8b in metric tons N2O and in metric tons CO2e (for Table AA-2 fuels only) [98.36(b)(8)(i), 98.36(c)(1)(vi), 98.36(c)(3)(vii), 98.273(c)(2)]

For each fuel type (not including biomass fuel(s)) for which you have elected to use the Tier 2 (Equation C-2a) methodology, you are required to report the following information by fuel type:

  • The total annual CO2 mass emissions derived from Equation C-2a in metric tons CO2 [98.36(b)(8)(i), 98.36(c)(1)(vi), 98.36(c)(3)(vii)]

  • The total annual CH4 mass emissions derived from Equation C-9a in metric tons CH4 and in metric tons CO2e (for Table AA-2 fuels only) [98.36(b)(8)(i), 98.36(c)(1)(vi), 98.36(c)(3)(vii), 98.273(c)(2)]

  • The total annual N2O mass emissions derived from Equation C-9a in metric tons N2O and in metric tons CO2e (for Table AA-2 fuels only) [98.36(b)(8)(i), 98.36(c)(1)(vi), 98.36(c)(3)(vii), 98.273(c)(2)]

  • Identification of each month for which HHVs were calculated using one or more substitute data values [98.36(e)(2)(ii)(C)]

  • The frequency of the HHV determinations [98.36(e)(2)(ii)(B)]

    • Hourly
    • Daily
    • Weekly
    • Monthly
    • Semiannually
    • Quarterly
    • Once per fuel lot
    • Upon addition of oil to the storage tank
    • Other (specify)

For each fuel type (not including biomass fuel(s)) for which you have elected to use the Tier 2 (Equation C-2c) methodology, you are required to report the following information by fuel type:

  • The total annual CO2 mass emissions derived from Equation C-2c in metric tons CO2 [98.36(b)(8)(i), 98.36(c)(1)(vi), 98.36(c)(3)(vii)]

  • The total annual CH4 mass emissions derived from Equation C-9b in metric tons CH4 and in metric tons CO2e (for Table AA-2 fuels only) [98.36(b)(8)(i), 98.36(c)(1)(vi), 98.36(c)(3)(vii), 98.273(c)(2)]

  • The total annual N2O mass emissions derived from Equation C-9b in metric tons N2O and in metric tons CO2e (for Table AA-2 fuels only) [98.36(b)(8)(i), 98.36(c)(1)(vi), 98.36(c)(3)(vii), 98.273(c)(2)]

For each fuel type (not including biomass fuel(s)) for which you have elected to use a Tier 3 (Equation C-3, C-4, or C-5) methodology, you are required to report the following information by fuel type:

  • The total annual CO2 mass emissions derived from Equation C-3 for solid fuels, Equation C-4 for liquid fuels, or Equation C-5 for gaseous fuels in metric tons CO2 [98.36(b)(8)(i), 98.36(c)(1)(vi), 98.36(c)(3)(vii)]

  • The total annual CH4 mass emissions derived from Equation C-8 in metric tons CH4 and in metric tons CO2e (for Table AA-2 fuels only) [98.36(b)(8)(i), 98.36(c)(1)(vi), 98.36(c)(3)(vii), 98.273(c)(2)]

  • The total annual N2O mass emissions derived from Equation C-8 in metric tons N2O and in metric tons CO2e (for Table AA-2 fuels only) [98.36(b)(8)(i), 98.36(c)(1)(vi), 98.36(c)(3)(vii), 98.273(c)(2)]

  • The total number of valid carbon content determinations [98.36(e)(2)(iv)(D)]

  • The total number of carbon content substitute data values [98.36(e)(2)(iv)(E)]

  • The frequency of carbon content determinations [98.36(e)(2)(iv)(B)]

    • Hourly
    • Daily
    • Weekly
    • Monthly
    • Semiannually
    • Quarterly
    • Once per fuel lot
    • Upon addition of oil to the storage tank
    • Other (specify)
  • The total number of operating hours in the reporting year for which missing data substitution was used for fuel usage [98.3(c)(8)]

For each gaseous fuel at each configuration for which you have elected to use the Tier 3 (Equation C-5) methodology, you are also required to report the following additional information:

  • Total number of valid molecular weight determinations [98.36(e)(2)(iv)(D)]

  • Total number of molecular weight substitute data values [98.36(e)(2)(iv)(E)]

  • Frequency of molecular weight determinations [98.36(e)(2)(iv)(B)]

    • Hourly
    • Daily
    • Weekly
    • Monthly
    • Semiannually
    • Quarterly
    • Other (specify)

Use the red-bordered text boxes to enter the required emissions information.

To calculate the emissions you have the option of using your own resources or alternatively you may use the following tool and set of instructions:

  • Download the spreadsheet tool by clicking the link below one of the red-bordered text boxes labeled "Use Tier X spreadsheet to calculate"
  • Fill in the spreadsheet completely using the instructions provided in the tool
  • After completing the spreadsheet, copy the values calculated by the spreadsheet to the red-bordered text boxes on this page

When you have finished entering emission results for the unit, click SAVE.

Repeat this step until emissions information has been entered for each fuel combusted by the unit.

Step 3: Save Your Data

Once you have entered emissions information for all fuels combusted by the unit, click Subpart AA Overview

After you save the data on this page, the next time you open the page, the calculator on the top of the page will display the CO2, CH4, and N2O process emissions, rounded to the nearest metric ton. The value displayed is for informational purposes only.

When CO2, CH4 and N2O process emissions have been entered the Status column on the Unit and Furnace Summary will show "Complete" and the background color for that furnace will show as green.

Click image to expand

#Back to Top

See Also

Screen Errors
Using Cal e-GGRT to Prepare Your Subpart AA Report
Subpart AA Summary Information for this Facility
Subpart AA Makeup Chemical Usage Information
Subpart AA Process Unit Information for Units NOT Monitored by CEMS
Subpart AA Process Unit Information for Units Monitored by CEMS
Subpart AA Emissions Information for Makeup Chemical Recovery
Subpart AA Emissions Information for Units NOT Monitored CEMS
Subpart AA Emissions Information for Units Monitored by CEMS
Subpart Validation Report

This web site is maintained by a contractor to the California Air Resources Board (RY2015.R.03)