Subpart D Information Sheet
Overview
Subpart D of the Greenhouse Gas Reporting Program (GHGRP) (40 CFR §§ 98.40 – 98.48) applies to any facility with one or more electric generating units and that meets the Subpart D source category definition. The Subpart D source category itself does not have a threshold reporting requirement; though, if multiple source categories are co-located at a facility with one or more electric generating units, the facility may need to report those other source categories under a different subpart, which may or may not have a threshold reporting requirement (see 40 CFR § 98.2(a)).
This Information Sheet is intended to help facilities reporting under Subpart D understand how the source category is defined, what greenhouse gases (GHGs) must be reported, how GHG emissions must be calculated and shared with EPA, and where to find more information.
On this page:
- How is This Source Category Defined?
- What GHGs Must Be Reported?
- How Must GHG Emissions Be Calculated?
- What Information Must Be Reported?
- What Records Must Be Maintained?
- When and How Must Reported Be Submitted?
- When Can a Facility Stop Reporting?
- For More Information
How is This Source Category Defined?
This source category consists of:
- Electricity-generating units that are subject to the requirements of the Acid Rain Program.
- Electricity-generating units that are required to monitor and report to EPA carbon dioxide (CO2) emissions year-round according to 40 CFR Part 75.
This source category excludes portable equipment or emergency generators, as defined in 40 CFR § 98.6.
What GHGs Must Be Reported?
Facilities must report the following:
- Annual mass emissions of CO2, nitrous oxide (N2O), and methane (CH4) emissions for each electricity-generating unit.
- For each electricity-generating unit that is not part of this category and for stationary fuel combustion units that do not generate electricity, report annual emissions of CO2, N2O, and CH4 by following the requirements of Subpart C (General Stationary Fuel Combustion Sources) found at 40 CFR § 98.30 – 98.38.
If multiple Greenhouse Gas Reporting Program (GHGRP) source categories are co-located at a facility, the facility may need to report greenhouse gas (GHG) emissions under a different subpart. Please refer to the relevant information sheet for a summary of the rule requirements and emissions calculation and reporting requirements for any other applicable source categories located at the facility.
How Must GHG Emissions Be Calculated?
Facilities must calculate GHG emissions as follows:
- Monitor and report CO2 mass emissions according to the applicable requirements of 40 CFR Part 75. Convert cumulative CO2 mass emissions reported in the fourth quarter from short tons (tons) to metric tons (tonnes).
- Calculate N2O and CH4 emissions by using the cumulative annual heat input to the unit, derived from the electronic data reports under 40 CFR Part 75, and emission factors provided in Subpart C (General Stationary Fuel Combustion Sources) found at 40 CFR § 98.30 – 98.38.
What Information Must Be Reported?
In addition to the information required by the General Provisions in Subpart A, found at 40 CFR § 98.3(c), the following must be reported:
- Unit or stack identification numbers. Use exact same unit, common stack, common pipe, or multiple stack identification numbers that represent the monitored locations (e.g., 1, 2, CS001, MS1A, CP001, etc.) that are reported under Part 75.
- Annual CO2 emissions at each monitored location, expressed in both tons and tonnes.
- Annual CH4 and N2O emissions at each monitored location, for each fuel type listed in Table C-2 that was combusted during the year (except as otherwise provided in 40 CFR § 98.33(c)(4)(ii)(B)), expressed in tonnes of carbon dioxide equivalent (CO2e).
- The total heat input from each fuel listed in Table C-2 that was combusted during the year (except as otherwise provided in 40 CFR § 98.33(c)(4)(ii)(B)), expressed in metric million British thermal unit (mmBtu).
- Identification of the Part 75 methodology used to determine the CO2 mass emissions.
- Methodology start date.
- Methodology end date.
- Acid Rain Program indicator.
- Annual CO2 mass emissions from the combustion of biomass, expressed in tonnes of CO2e.
- If applicable, the plant code (as defined in 40 CFR § 98.6).
What Records Must Be Maintained?
Reporters are required to retain records that pertain to their annual GHGRP report for at least three years after the date the report is submitted. Please see the Subpart A Information Sheet and 40 CFR § 98.3(g) for general recordkeeping requirements. Specific recordkeeping requirements for Subpart D are listed at 40 CFR § 98.47.
When and How Must Reports Be Submitted?
Reporters must submit their annual GHGRP reports for the previous calendar year to the EPA by March 31st, unless the 31st falls on a Saturday, Sunday, or federal holiday, in which case reports are due on the next business day. Annual reports must be submitted electronically using the electronic Greenhouse Gas Reporting Tool (e-GGRT), the GHGRP’s online reporting system. For facilities required to use the e-GGRT Inputs Verifier Tool (IVT), reporters must enter required data into the e-GGRT IVT, which includes inputs to emission equations for which reporting is not required. IVT uses these data to calculate the equation results.
Each report may be prepared by either a designated representative, an alternate designated representative or agent(s) of the owner or operator. Additional information on setting up user accounts, registering a facility, and submitting annual reports is available on the GHGRP Help webpage.
When Can a Facility Stop Reporting?
A facility may discontinue reporting under several scenarios, which are summarized in Subpart A (found at 40 §CFR 98.2(i)) and the Subpart A Information Sheet.
For More Information
For additional information on Subpart D, please visit the Subpart D webpage. For additional information on the GHGRP, please visit the GHGRP website, which includes additional information sheets, data previously reported to the GHGRP, training materials, and links to FAQs. For questions that cannot be answered through the GHGRP website, please contact us at: [email protected].
This Information Sheet is provided solely for informational purposes. It does not replace the need to read and comply with the regulatory text contained in the rule. Rather, it is intended to help reporting facilities and suppliers understand key provisions of the GHGRP. It does not provide legal advice; have a legally binding effect; or expressly or implicitly create, expand, or limit any legal rights, obligations, responsibilities, expectations, or benefits with regard to any person or entity.
Archived Versions
Links to external websites or other EPA webpages in older documents may not work. Although some content may be current or applicable, older resources on this page are intended for reference and historical documentation purposes.