In referencing the AERR, the SIP inventory requirements do not mention specific pollutants for which the AERR point source definition (which uses reporting thresholds for all CAPs) should be used. For example, the ozone implementation rules' inventory requirements rely on CAA Section 172(c)(3), which requires emissions of "the relevant pollutant or pollutants" when preparing nonattainment SIP inventories for ozone. In the case of ozone, these relevant pollutants are NOx and VOC, but the references from the ozone SIP requirement rules to the AERR are not specific to these pollutants. Thus, under the current approach, one could incorrectly assume that all AERR point sources defined with all CAP PTE reporting thresholds would need to be treated as point sources for an ozone SIP, irrespective of the level of NOx and VOC at those sources. This proposal clarifies that only those sources with NOx or VOC emissions exceeding the AERR point source PTE reporting thresholds would be required to be reported as point sources in an ozone SIP. Similarly, this proposal would include similar clarifications for PM2.5 and its precursors when preparing nonattainment SIP inventories for PM2.5. In addition, the EPA intends for the addition to the point source definition included in this proposal based on HAP should not impact the point source definition for SIPs.
To ensure no change to the other subparts that refer to the AERR's point source requirements, the EPA proposes to revise §51.10 of this subpart by adding paragraph (b) to list Part 51 Subparts G, X, Z, AA, and CC and specify the parts of the point source definition that are applicable to each. Specifically, for Subpart G, the EPA proposes that only the NOX reporting threshold of the proposed Table 1A to Appendix A of this subpart would be relevant. For ozone implementation under Subparts X, AA, and CC, the EPA proposes that the NOX and VOC reporting thresholds of the proposed Table 1A to Appendix A of this subpart would be relevant. For PM implementation under Subpart Z, the EPA proposes that the NOX, VOC, SO2, NH3, PM2.5, and PM10 reporting thresholds of the proposed Table 1A to Appendix A of this subpart would be relevant.
2. Detail Required by Emission Inventory Provisions of SIP Implementation Rules
In addition to the point source definition referenced throughout Part 51, the SIP requirements within Part 51 refer to the AERR by requiring that the detail of the emissions inventory under those subparts "shall be consistent with the data elements required by 40 CFR Part 51, Subpart A" (see 40 CFR 51.122(g), §51.915, §51.1008 (a)(1)(vi), §51.1115(e), and §51.1315(e)). Several revisions are being proposed by this action that would impact the "detail of the emissions inventory," so additional information has been included in this proposed action to clarify which changes do not apply to the SIP inventory requirements.
The proposed revisions to this subpart for state requirements regarding the "detail of the emissions inventory" have been described above and are summarized here to provide clarity about which changes would need to be considered when interpreting the Part 51 references to the AERR. Table 4 below lists the proposed changes to relevant requirements of action in the left column and how the EPA proposes that they would or would not impact the "detail of the emission inventory" requirement included in the SIP inventory requirements.
Table 4: Impacts of proposed state reporting requirements on 40 CFR Subparts G, X, Z, AA, and CC.

Proposed new or revised state reporting requirement for the AERR
Impact of proposed requirement on 40 CFR subparts G, X, Z, AA, and CC? (Yes/No)
1
Requirement to report intermittent electricity generation fuel use (section IV.D of this preamble).
No: Does not change emissions required to be reported under these subparts. Emissions (but not daily activity data) from intermittent electricity generation sources would continue to be required to be included in SIP inventories. The proposed AERR revisions improve states' ability to gather the data they need to estimate and consider these emissions in SIPs.
2
Requirements to use source test data when available, indicate why it is not used, and otherwise use best available emissions estimation method (sections IV.I.6 and IV.I.7 of this preamble)
Yes: Point source emissions would need to be estimated as proposed in new §51.5(a) through (d) of the proposed regulatory text.
3
Additional required point source data fields (sections IV.E, IV.I.3, IV.I.4, IV.I.5, IV.I.8, IV.I.10, IV.I.11, IV.I.12, and IV.I.16 of this preamble)
Yes: Point source inventories developed and submitted under these subparts would need to include additional data fields. See new §51.15(j)(1) and §51.40(b) of the proposed regulatory text.
4
More specific airport and rail yard requirements and implementation options (sections IV.I.1 and IV.I.2 of this preamble)
No: Airport and rail yard emissions are still required as point sources if those facilities exceed the point source reporting thresholds in Table 1A to Appendix A of this subpart. See new §51.15(j)(1) of the proposed regulatory text.
5
Requirement to complete an online nonpoint survey (section IV.J of this preamble)
No: Only relevant for NEI process and not for SIPs. See New §51.15 and §51.15(j)(2) of the proposed regulatory text.
6
Requirement to report nonpoint activity data and optionally report emissions data for some emissions sectors, including an option to review and accept EPA-provided data to comply (section IV.J of this preamble)
No: Nonpoint emissions are still required. See new §51.15 and §51.15(j)(2) of the proposed regulatory text.
7
Requirement for documentation when nonpoint emissions are reported (section IV.J of this preamble)
No: Nonpoint emissions are still required and no additional documentation requirement. See new §51.15 and §51.15(j)(2) of the proposed regulatory text.
8
Requirement for documentation when onroad and nonroad emissions are reported by California or by other states when they optionally provide emissions in addition to MOVES inputs (section IV.O of this preamble)
No: Onroad and nonroad emissions are still required and no additional documentation requirement. See new §51.15 and §51.15(j)(3) of the proposed regulatory text.
9
Specific approach for reporting nonpoint activity data and emissions when Indian country boundaries overlap with county boundaries (section IV.L of this preamble)
Yes (for states overlapping tribes that have emissions inventory reporting obligations): Clarifies how states and tribes should report nonpoint, onroad, and nonroad emissions when both the state and the tribe have implementation planning authority within a nonattainment area. See new §51.15 and §51.15(j) paragraphs (2)(iv) and (3)(ii) of the proposed regulatory text.
10
Requirement to report prescribed burning activity data (section IV.M of this preamble)
No: Prescribed fire emissions are still required. See new §51.15 and §51.15(j)(2)(ii) of the proposed regulatory text.
11
Change to make agricultural burning optional and submitted as an event source (section IV.N of this preamble)
No: Agricultural burning emissions are still required as a nonpoint source. See new §51.15 and §51.15(j)(2)(ii) of the proposed regulatory text.
As shown in the table above, only three of the proposed changes for state annual or triennial reporting under this action impact the requirements of Part 51 Subparts G, X, Z, AA, and CC. The three that do impact the requirements help with resolving ongoing nonattainment emissions data challenges, so it is appropriate for these subparts to continue to refer to the AERR as revised.
For the proposed requirement 1 in Table 4, more completely described in section IV.D of this preamble, the proposed change to the AERR has a positive impact on emissions data that would be available to the state after implementing the provisions of this action. This proposed action facilitates activity data collection from small generating units as an annual requirement, which would allow states with small generating units operating to offset or meet peak electricity demand to have the data that they need to better reflect emissions from such sources in their planning inventories for SIPs.
The proposed set of requirements listed as item 2 in Table 5 specifies data quality requirements for calculating and reporting emissions for point sources. These are described more completely in sections IV.I.6 and IV.I.7 of this preamble. If these proposed requirements were finalized, point sources reporting CAP emissions to states for both annual emissions reporting to the EPA and SIP purposes would need to meet new data quality requirements.
The proposed requirement 3 in Table 4 is a collection of specific new data fields that are more completely described in section IV.I of this preamble and the proposed Table 2A to Appendix A of this subpart. Any new data elements finalized from this proposed action would be collected by states to meet requirements of the AERR and, therefore, would be available for states to submit as part of their planning inventories for SIPs. Thus, while the SIP inventory requirements are indirectly modified by this proposed action, this action does not impose additional burden for nonattainment area inventories because this subpart uses the same requirements for both annual reporting of point sources and for states' planning inventories for SIPs.
Finally, the proposed requirement 9 of proposed Table 4 is fully described in section IV.L of this preamble addresses an existing challenge for both the NEI and SIP planning inventories. As previously described, a clear approach for states and tribes to share reporting of county total emissions data has not been available. When both a state and an Indian Tribe share implementation planning authority for a nonattainment area, this action proposes a new requirement for how states and tribes (or the EPA on their behalf) should develop and report nonpoint, onroad, and nonroad emissions. As proposed in new paragraph §51.15(j), subparagraphs (2)(iv) and (3)(ii) of the proposed regulatory text, the approach would apply the same technique described for nonpoint activity and emissions for triennial reporting to the emissions reporting for the nonattainment area needed for SIPs. To be clear, this situation would arise if the nonattainment area included some lands that fell within the geographic scope of the state's implementation planning authority as well as some lands within the geographic scope of the tribe's implementation planning authority in accordance with TAS for that tribe.
In evaluating the connection between the elements required to be reported under the AERR and the elements required to be provided in SIP submissions pursuant to other Part 51 subparts that generally reference the AERR, the EPA noticed several differences. The current AERR includes some requirements that were intended to apply only to the triennial NEI emissions data collection and not to impact requirements for SIPs. The primary discrepancy is that as per CAA Section 172(c)(3), SIPs "shall include a comprehensive ... inventory of actual emissions from all sources of the relevant pollutant or pollutants." The "comprehensive" and "all sources" part of this requirement are not technically satisfied for certain provisions of the AERR. For example, the AERR allows for reporting model inputs (rather than "emissions") for mobile sources. Similarly, the AERR makes optional certain important emissions sources such as windblown dust, biogenic emissions from soils and vegetation, prescribed fires, and wildfires, but these sources must generally be included in inventories pursuant to 172(c)(3). The EPA provides guidance documents and training for SIP inventory preparation that help ensure that these differences do not result in inadequate SIP inventories. This action proposes to provide additional clarity on these issues regarding what states need to report.
Part of this additional clarity has previously been described in section IV.R.1 of this preamble regarding which pollutants should be included in SIP planning inventories associated with the Part 51 subparts that reference the AERR. In addition, this proposed action includes a new paragraph §51.15(j) in the proposed regulatory text that lists out inventory requirements for SIPs required under Part 51 Subparts G, X, Z, AA, and CC that are different from requirements for annual or triennial reporting for the NEI. First, this proposed action, when referring to SIP planning inventories, would define point sources only by the relevant CAP point source reporting thresholds under a new paragraph §51.10(b) in the proposed regulatory text and not by the other criteria such as the new criteria for HAP for major and non-major sources. This proposed revision would retain the existing definition of point sources in this subpart for references from other Part 51 subparts to the AERR. Second, this proposed action would clarify that for SIP planning inventories, airports and railyards would need to be reported as point sources only when they meet the point source reporting threshold and otherwise could be included as a nonpoint (county-total) source. This contrasts with the triennial requirement for which the EPA provides data for review and comment by states for all airports and railyard data, including ones much smaller than the point source reporting thresholds. Third, this proposed action would further clarify in new paragraph §51.15(j)(2)(iii) that SIP planning inventories should include emissions from all sources, irrespective of any other approaches required or made optionally available by the AERR for the triennial submission of nonpoint, onroad, and nonroad sources.
3. Emission Inventory Years
The third and final type of reference to the AERR from other subparts within Part 51 is about the year of the triennial NEI. Such references appear in Subpart P at §51.308(f)(2)(iii) and §51.308(g)(4); Subpart X at §51.910(d); Subpart AA at §51.1110(b), and Subpart CC at §51.1310(b).
Subpart P provides requirements for state implementation of the regional haze program, and §51.308(f)(2) provides the requirements for the long-term strategy to be included in periodic revisions of regional haze SIPs. For emissions inventories, paragraph (f)(20)(ii) states that "[t]he emissions information must include, but need not be limited to, information on emissions in a year at least as recent as the most recent year for which the State has submitted emission inventory information to the Administrator in compliance with the triennial reporting requirements of Subpart A of this part." Additionally, paragraph (g)(4) of the same section provides requirements for periodic reports describing progress towards the reasonable progress goals; and this paragraph has a similar reference to the year of triennial submissions to indicate the period over which the state must perform an analysis tracking the change in emissions. No provision of this proposed action would impact the inventory year required for regional haze SIPs, because this action proposes to retain triennial inventory requirements. Thus, under this action, the subpart P requirement that references triennial reporting is still relevant since emissions inventories would continue under this proposed action to be collected on triennial inventory years.
Within Part 51 Subpart X, §51.910(d) addresses what year should be used for the baseline emissions inventory for Reasonable Further Progress (RFP) plans. This paragraph requires that the appropriate year is at least as recent as the most recent year for which a complete inventory is required to be submitted to the EPA under the provisions of the AERR. The phrase "complete inventory" means the triennial inventory, which are the only inventories for which all source categories could be reported by a state under the AERR. No provision of this proposed action would impact the inventory year required for SIPs under Subpart X, because this action proposes to retain triennial inventory requirements.
Part 51 Subpart AA includes the same statement to specify the baseline emission inventory year needed to meet requirements for RFP, which appears at §51.1110(b). In addition, §51.1115(a) refers to the year used for the baseline emission inventory for RFP to explain which years can be used for the base year inventory for the nonattainment area. Likewise, Part 51 Subpart CC includes the same reference to the triennial inventory year at §51.1310(b). In all cases, no provision of this proposed action would impact the inventory year required for SIPs under Subparts X, AA, or CC because this action proposes to retain triennial inventory requirements.
S. Summary of Expected Timing for Proposed Revisions
Unless otherwise noted, the proposed revisions in this action would apply for the first inventory reporting year after promulgation of the final rule. At the time of this proposal, the EPA expects that the final rule will be in place for the 2023 triennial reporting year, though some provisions would not take effect until later years. These proposed deadlines depend on an assumed final rule promulgation date prior to December 2024. If a final version of this subpart were delayed beyond December 2024, the EPA may delay the phase-in of earlier deadlines. Table 5 below summarizes the intent of this proposed action with respect to deadlines.
Table 5: Proposed first possible date for deadlines associated with proposed revisions to 40 CFR 51 Subpart A.
First possible date
Requirement
                       Dates for states - point sources.
11/1/2025
Proposed first deadline to notify the EPA if intend to use CAERS (for 2026 inventory year)
9/30/2024
Proposed first deadline for states/locals to submit landing and takeoff data for the 2023 inventory year (could be later than this, since states have minimum of 60 dates to review)
1/15/2025
Proposed deadline for air agencies 2023 NEI point source reporting (for CAP and voluntary HAP including airports and rail yards)
1/15/2026
Proposed deadline for air agencies 2024 NEI point source reporting (for CAP and voluntary HAP)
3/31/2026
Proposed first deadline for states to submit their HAP reporting application (for the 2026 inventory year)
1/15/2027
Proposed deadline for 2025 NEI point source reporting (for CAP and voluntary HAP)
1/15/2028
Proposed deadline for 2026 NEI point source reporting, for CAP and mandatory HAP when the state has an approved HAP reporting application. Includes the first year for mandatory reporting for intermittent EGUs and required new data fields including release point coordinates, title V permit ID, regulatory codes, and changes to portable sources reporting.
9/30/2028
Proposed first deadline for earlier state point source reporting (for 2027 inventory year). This is also the first deadline for which the same point sources must be reported each year (no higher reporting thresholds for non-triennial inventories).
5/31/2031
Proposed first deadline for even earlier state point source reporting (for 2030 inventory year and later).
                Dates for states - other sources besides point
1/15/2025
Proposed deadline for 2023 NEI for rail yards, mobile source inputs, California mobile source emissions and documentation, and nonpoint source emissions and documentation for sources without EPA tools
3/31/2025
Proposed deadline for 2023 NEI nonpoint survey
7/1/2027
Proposed first deadline for required annual prescribed burning activity data
Within 30 days, or longer as provided by EPA
Proposed timing for states to report nonpoint tool inputs during the year of the inventory and the year after (e.g., during 2023 and 2024 for the 2023 triennial inventory year)
Within 60 days, or longer as provided by EPA
Proposed timing for states to report nonpoint emissions data for nonpoint sources with EPA tools (e.g., during 2023 and 2024 for the 2023 triennial inventory year).
                          Dates for owners/operators
10/31/2024
Proposed deadline for the "One-time Collection Option" for HEDD-related small generating units (if this option were selected for the final rule)
5/31/2025
Proposed deadline for voluntary reporting by owners/operators (for the 2024 inventory year).
5/31/2026
Proposed deadline for owners/operators with point sources within Indian country not reported by tribes to report CAP and HAP (for the 2025 inventory year). Also, the deadline for voluntary reporting by other owners/operators.
5/31/2027
Proposed first deadline for all owners/operators to report HAP for 2026 reporting year.
3/31/2028
First earlier proposed deadline for owners/operators to report for the 2030 reporting year.
To meet Federal or state testing requirement or otherwise within 60 days after completing testing
Source test/performance test collection
T. Summary of Regulatory Impact Analysis
In this preamble section, we briefly summarize the costs and benefits of this proposal. The RIA for this proposed rule provides additional detail on these costs and benefits. The EPA encourages commenters to provide any additional information not considered in the RIA for this proposed rule or to provide comments on EPA's cost estimation approaches.
While methodological limitations prevented the EPA from monetizing the potential human health and environmental benefits, given that no changes in emissions or other environmental effects can currently be estimated that may be directly attributed to the greater availability and quality of emissions data, and in particular HAP emissions, we present a qualitative discussion of benefits. These benefits include those to communities that may be particularly impacted by pollutant emissions, whether they be HAP or CAP.
The benefits of the proposed revisions to the AERR of collecting additional HAP, CAPs, controls, and sub-facility data include improved understanding, awareness, and decision making related to the provision and distribution of information. The information shared with EPA, and incorporated into the NEI, could enable the public to make more informed decisions on where to live and work, strengthen the public's ability to adequately protect themselves from potential harm from criteria air pollutants and air toxics, and provide a greater capacity for meaningful involvement in the development and implementation of local pollution management policies.
This proposed action would ensure that communities have the data needed to understand significant sources of air pollution that may be impacting them and address existing environmental justice issues that are discussed previously in this preamble. Additional benefits to these communities include building public confidence through clear and transparent emission measures and reports and the ability of the public to better make facilities accountable for their emissions. Availability of increased information on HAP emissions can also be used to advance the Agency's environmental justice goals by increasing the understanding of the potential impacts of air toxics emissions from regulated facilities on minority and disadvantaged communities who have been historically burdened by often difficult to detect and undisclosed pollution that is experienced on a regular basis. The required reporting of HAP emissions data will increase EPA's ability to accurately conduct technology reviews pursuant to CAA Section 112(d)(6), and risk reviews under CAA Section 112(f)(2), which should lead to future regulation of HAP that will be more effective in reducing the burden of exposure of such emissions from what has occurred in the past. These provisions are additionally informed by federal policy on environmental justice, including Executive Order 12898, which overlays environmental justice considerations for the EPA to assess as part of such work. Even for owners/operators who also must report emissions to the TRI program, this proposed action would require additional sub-facility details necessary for air quality modeling that, in turn, would allow the EPA and other authorities to assess local-scale community impacts and devise solutions for high-risk areas.
The proposed amendments would ensure HAP emissions data are collected consistently for all communities across the country. Currently, the availability and detail of HAP emissions data varies across states, which creates a situation where some communities have incomplete or less accurate information than others, while still facing the same or greater potential risks. Transparent, public data on emissions allows for accountability of polluters to the public stakeholders, including communities, that bear the social cost of the pollution.
Finally, the proposed provision of additional information could also lead to behavioral changes that could result in additional benefits. In particular, voluntary initiatives by facilities to review emissions control management practices and facility processes, set goals for reductions in emissions, and institute "good neighbor" policies may result from provision of additional emissions data. Potential changes in facility operations, such as reductions in pollutant releases, could yield health and environmental benefits. There may be instances where pollutant emissions are themselves valuable product from a market standpoint (e.g., natural gas, that includes HAP and methane, leaking from a pipeline), and their control or capture may not only be beneficial to the environmental but also beneficial to the firms that own the natural gas. While behavioral changes from the provision of information may result from the rule and are, in fact, one goal of these types of policies, they are not mandated by the proposed action. The reporting of such emission data, and its public disclosure, may provide social benefits in itself since this data disclosure may incentivize emission reductions.
Regarding the costs of this proposal, the proposed rule's cost to State, local, tribal government authorities is estimated at $28.5 million on average annually from 2024 to 2026, and then is estimated at $27.7 million in 2027. For owners and operators of affected sources, the proposed rule's cost is estimated at $89.0 million on average annually from 2024 to 2026, and then is estimated at $450.1 million in 2027. Thus, the proposed rule's total cost impact is estimated at $117.4 million on average annually from 2024 to 2026, and then is estimated at $477.9 million in 2027. All of these costs are in 2021 dollars. The increase in costs for owners and operators of affected sources in 2027 reflects full implementation of the proposed rule if finalized for the entire population of affected sources.
Regarding the population of affected sources for the 2024-2026 time period, the EPA estimates the proposed rule would impact 85 state/local/tribal respondents and 820 owners/operators of facilities outside of states' implementation planning authority. Owners/operators for an estimated 40,315 facilities per year would also need to prepare for new reporting requirements starting in 2027. Also, during this period, the EPA estimates that owners/operators of 13,420 facilities would report source test and performance evaluation data each year. Based on these proposed requirements, states would continue to collect emissions data from owners/operators of an estimated 13,420 facilities (based on state regulations requiring owners/operators to do so).
Starting in 2027, the EPA estimates that, under the proposed AERR, owners/operators from about 129,490 facilities would be required to report HAP as would about 235 owners/operators for reporting small generating unit data. More information on the costs and estimates of affected facilities can be found in the ICR supporting statement and the RIA for this proposal, located in the docket for this action.
In addition, as part of fulfilling analytical guidance with respect to E.O. 12866, EPA presents estimates of the present value (PV) of the social costs of the proposal over the period 2024 to 2033, an analytical timeline that is approximately the first 10 years after this rule is finalized as proposed. To calculate the present value of the social costs of the proposed rule, annual costs are discounted to 2023 at 3 percent and 7 discount rates as directed by OMB's Circular A-4. The EPA also presents the equivalent annualized value (EAV), which represents a flow of constant annual values that, had they occurred in each year from 2024 to 2033, would yield a sum equivalent to the PV. The EAV represents the value of a typical cost or benefit for each year of the analysis, consistent with the estimate of the PV, in contrast to the year-specific estimates mentioned earlier in the RIA. The PV of the compliance costs, in 2021 dollars and discounted to 2023, is $2.41 billion when using a 7 percent discount rate and $3.06 billion when using a 3 percent discount rate. The EAV, an estimate of the annualized value of the costs consistent with the present values, is $343 million when using a 7 percent discount rate and $358 million when using a 3 percent discount rate. Table 6 summarizes the costs and benefits of this proposal.
Table 6. Summary of Benefits, Costs and Net Benefits for the Proposal from 2024 to 2033, Discounted to 2023 (Million 2021$[a])

                               Proposal Impacts

                                  3 Percent
                                  7 Percent

                                      PV
                                      EAV
                                      PV
                                      EAV
                          Total Monetized Benefits[a]
                                      N/A
                                      N/A
                                  Total Costs
                                    $3,057
                                     $358
                                    $2,410
                                     $343
                                 Net Benefits
                                      N/A
                                      N/A
                            Non-monetized Benefits
Improved emissions data access for state, local, and tribal government agencies
 Increased emissions data for addressing local (environmental justice) issues
               Better data to inform regulatory decision making
Increased emissions data to incentivize voluntary emission reduction efforts by industry and others

[a] We have determined that quantification of benefits cannot be accomplished for this proposed rule. This is not to imply that there are no benefits of the proposal; rather, it is a reflection of the difficulties in monetizing the benefits for the listed categories with the data currently available. N/A = not available.

    These cost estimates include those for impacts to State, local, and Tribal organizations that are engaging in voluntary activities that would become codified as a result of this proposal if finalized. The EPA has broken out those costs separately and provides discussion of them in the RIA for this proposal. Similarly, we acknowledge that the cost estimates for this proposal include those for revisions to SIP planning activities, and we also break out these costs separately and provide discussion of them in the RIA for this proposal.

V. Statutory and Executive Order Reviews
Additional information about these statutes and Executive Orders can be found at HYPERLINK "https://www.epa.gov/laws-regulations/laws-and-executive-orders"https://www.epa.gov/laws-regulations/laws-and-executive-orders.
A. Executive Order 12866: Regulatory Planning and Review and Executive Order 13563: Improving Regulations and Regulatory Review
This action is a "significant regulatory action", as defined under section 3(f)(1) of Executive Order 12866, as amended by Executive Order 14094. Accordingly, EPA, submitted this action to the Office of Management and Budget (OMB) for Executive Order 12866 review. Documentation of any changes made in response to the Executive Order 12866 review is available in the docket. The EPA prepared an analysis of the potential costs and benefits associated with this action. This analysis, "Regulatory Impact Analysis for the Proposed Revisions to the Air Emissions Reporting Requirements," is also available in the docket and is briefly summarized in Section IV.T of this preamble.
B. Paperwork Reduction Act
The information collection activities in this proposed rule have been submitted for approval to the Office of Management and Budget (OMB) under the Paperwork Reduction Act, 44 U.S.C. 3501 et seq. The draft Information Collection Request (ICR) document prepared by the EPA has been assigned the EPA ICR number 2170.09. You can find a copy of the ICR in the docket for this rule, and it is briefly summarized here.
In past years, the information collection under the existing AERR has coordinated the various state emission inventory reporting requirements and has streamlined the activities involved in submitting certain emissions data to the EPA. The proposed revisions to the collection would (1) continue this coordination to enable the EPA to achieve uniformity and completeness in a national inventory to support national, regional, and local air quality planning and attainment of NAAQS and planning needed for meeting regional haze requirements, (2) greatly improve HAP data collections that are voluntary under the existing AERR, but are proposed herein to become mandatory (3) fill other identified gaps in emissions inventories for sources within Indian country, for certain small generation units, and for prescribed fires nationally, and (4) greatly improve the availability of data necessary for creating emissions factors.
The draft ICR for this proposed action includes collection of both mandatory and voluntary data from states (as defined in section III to include certain local and tribal governments) for annual and more extensive triennial collections of emissions data. The draft ICR also covers the proposed collection of mandatory and voluntary data from owners/operators that emit emissions at or above proposed reporting thresholds and that perform source tests. While the focus of the draft ICR is the 2024-2026 period, additional costs from 2027 and beyond are included in Appendix A of the draft ICR to reflect additional costs associated with full implementation of the proposed revisions.
Respondents/affected entities: For the 2024-2026 period covered by the draft ICR, the EPA estimates the proposed rule would impact 85 state/local/tribal respondents and 813 owners/operators of facilities outside states' implementation planning authority. Also, during this period, the EPA estimates that owners/operators of 13,420 facilities would report source test and performance evaluation data each year and 120,945 facilities (40,315 per year) would collect release point latitude/longitude data for reporting in 2027. Based on these proposed requirements, states would continue to collect emissions data from owners/operators of an estimated 13,420 facilities (based on state regulations requiring owners/operators to do so).  during this period, the EPA estimates that owners/operators of 13,420 facilities would report source test and performance evaluation data each year. Based on these proposed requirements, states would continue to collect emissions data from owners/operators of an estimated 13,420 facilities (based on state regulations requiring owners/operators to do so). Starting in 2027, Appendix A of the draft ICR identifies owners/operators of an estimated 129,500 facilities from which this proposed rule would require HAP reporting and for about 235 owners/operators, reporting of small generation unit data.
Respondent's obligation to respond: Under this proposed action, the EPA estimates that 85 governmental entities would be required to report to EPA. Authority for such collection is provided by CAA Sections 110, 114, 172, 182, 187, 189, and 301(a). In addition, owners/operators would be required to report data to EPA, and authority for these collections is provided by the same CAA sections. Additionally, 7 railroad companies are expected to voluntarily provide data to the EPA once every three years but would be under no obligation to do so.
Estimated number of respondents: During the 2024-2026 period, the EPA expects 85 governmental entities, owners/operators from an estimated 14,233 facilities (13,420 to states and 819 to EPA), and owners/operators of 7 railroads to respond. The description above provides additional detail on the numbers and types of respondents for the draft ICR period and for subsequent periods.
Frequency of response: States would submit emissions data annually, with more data required every third year. Owners/operators of facilities within Indian country would report each year, starting in 2026 (for the 2025 emissions inventory year). The frequency of source test data reports depends on the testing requirements set by the EPA and states. Frequency can range from several times per year to once every several years. However, for the purpose of the draft ICR, the EPA estimates that owners/operators reporting source test data would report an average of 3 source tests per year. Starting in 2027, the states and owners/operators of facilities affected by this proposed rule would report the same amount of point source data every year. Also starting in 2027, states would report prescribed burning data each year. No change is being proposed to triennial reporting frequency for nonpoint and mobile sources.
Total estimated burden: All burden estimates include additional burden associated with proposed options included in the preamble (or the most costly option when multiple options are described). Table 6 includes total estimated burden split by respondent, activity, and mandatory or voluntary activities. Total estimated burden for all entities combined is 1,142,927 hours for mandatory activities and 99,115 for voluntary hours during the 3-year period of this ICR. Of this, the estimated burden for states is 317,454 hours for mandatory activities and 99,087 for voluntary activities. Estimated burden for owners/operators is 825,473 hours for mandatory activities and 28 hours for voluntary activities. Burden is defined at 5 CFR 1320.3(b).
Table 6: Total Estimated Burden for proposed requirements for 2024-2026
Entity
Activity
                                Mandatory Hours
                                Voluntary Hours
                                  Total Hours
                                    States
Update emissions regulations and build prescribed burning collection system
                                                                        156,784

                                                                        156,784

Convert to CAERS and apply to report HAP

                                                                        88,554

                                                                        88,554

Emissions reporting to EPA
                                                                         45,456
                                                                         10,533
                                                                         55,990

Maintaining emissions collection system (Operations/Maintenance)
                                                                        115,214

                                                                        115,214

                                                            State AERR SubTotal
                                                                        317,454
                                                                        99,087

                                                                       416,542

                               Owners/
Operators
Source test reporting
                                                                        161,040

                                                                        161,040

Emissions data reporting to the EPA (Indian country and rail companies)
                                                                         11,382
                                                                             28
                                                                         11,410

Reporting required data (for AERR) to SLTs
                                                                        144,993

                                                                        144,993

Preparing to report release point locations

507,973

507,973

                                                      Owners/Operators SubTotal
                                                                      825,473

                                                                             28
                                                                      825,501

                                                                          Total
                                                                    1,142,927

                                                                        99,115

                                                                    1,242,043

The draft ICR additionally provides, via Appendix C, state and owner/operator hours and costs associated with emissions data activities for SIP preparation, in compliance with OMB expectations that the EPA include those costs. Since those costs are not burden associated with the proposed revisions to the AERR, they are not included in Table 6, but are noted here as EPA requests comment on the burden estimates.
Total estimated cost: Annual capital or operation & maintenance costs include costs for the EPA and states. The EPA's expected annual capital costs for its data systems needed from 2024 through 2026 are $600,000. EPA's additional annual system development, operations, and maintenance costs are expected to be $3,625,000. States' total annualized capital costs are estimated to be $127,500, and their operation and maintenance costs about $10,156,000.
An agency may not conduct or sponsor, and a person is not required to respond to a collection of information unless it displays a currently valid OMB control number. The OMB control numbers for EPA's regulations in 40 CFR Part 51 are listed in 40 CFR Part 9.
Submit your comments on the agency's need for this information, the accuracy of the provided burden estimates, and any suggested methods for minimizing respondent burden to the EPA using the docket identified at the beginning of this rule. You may also send your ICR-related comments to OMB's Office of Information and Regulatory Affairs via email to<EMAIL_ADDRESS>Attention: Desk Officer for EPA. Since OMB is required to make a decision concerning the ICR between 30 and 60 days after receipt, OMB must receive comments no later than [insert date 30 days after publication in the Federal Register]. The EPA will respond to any ICR-related comments in the final rule.

C. Regulatory Flexibility Act
Pursuant to Section 603 of the RFA, the EPA prepared an initial regulatory flexibility analysis (IRFA) that examined the impact of the proposed rule on small entities along with regulatory alternatives that could minimize that impact. The complete IRFA is available for review in the docket (see Chapter 4 of the RIA in the docket for this proposal) and is summarized here. The EPA is soliciting comment on the presentation of its analysis of the impacts on small entities. As required by Section 604 of the RFA, the EPA will prepare a final regulatory flexibility analysis (FRFA) for this action as part of the final rule. The FRFA will address the issues raised by public comments on the IRFA.
EPA is considering this proposal to fill gaps in the existing available emissions inventory data, most notably for HAPs, prescribed burning, and small generation units related to HEDD events. The HAP data collection supports improved understanding of pollutants surrounding at-risk communities. Additionally, the proposed revisions to the AERR would further streamline air emissions reporting, allow for improved consistency of emissions calculation methods, quality, and transparency of state-provided data.
Through this proposal, the EPA will have improved emissions data on which to make decisions affecting implementation of the Clean Air Act for both the air toxics program and the NAAQS. As described in section III of this proposal, the EPA is proposing these amendments pursuant to its authority under CAA Sections 110, 111, 112, 113, 114, 129, 172, 182, 187, 189, and 301 (see also section III of this proposal). Further, EPA's proposal supports better understanding of pollution to inform the EPA as it works to include environmental justice considerations as described by EO 12898 (see also section IV.A.1 of this proposal).
EPA estimates that small entities will be affected by this proposal when they are major sources, and for non-major sources, have primary NAICS as listed in section II of this proposal. The EPA estimates that approximately 34,800 small entities could be impacted by this rule based on the CAA definition that the EPA proposes to use for this rule. That number would increase to approximately 44,600 if the EPA were to use the SBA definition.
Based on this proposal, affected small entities would need to report unit-level information about their facilities and report facility-wide emissions in most circumstances. The small business accommodation that this proposal offers to small businesses to report with less detail could be eliminated for certain facilities if data submitted in past inventory years shows, through EPA modeling, an unacceptable level of risk. Small entities will need to be able to record basic information about their facility such as fuel consumed by certain activities, electricity used, amount of solvents consumed, amount of product produced, or number of employees. Small entities will additionally need to be able to enter this information in electronic forms.

 The EPA has reviewed other EPA emissions reporting requirements for duplication and is aware of the potential for duplication of limited data elements for certain other EPA collections, though it is not aware of any collection that is wholly or significantly duplicative. Further, the EPA is actively working to avoid this duplication with its CAERS development efforts. These potentially duplicative requirements include 40 CFR Part 75, 40 CFR Part 98, and 40 CFR Part 372. The EPA requests comment on whether this list is comprehensive.
EPA is considering a number of alternatives in this proposed rule to minimize any significant economic impact of the proposed rule on small entities. These proposed approaches are described in sections IV.A.12 through IV.A.14 of this preamble. The EPA has included various accommodations for small entities in the proposed rule based on recommendations from the SBAR Panel Report, and these are additionally reflected in the IRFA and proposed ICR.
As required by Section 609(b) of the RFA, the EPA also convened a Small Business Advocacy Review (SBAR) Panel to obtain advice and recommendations from small entity representatives that potentially would be subject to the rule's requirements. The SBAR Panel evaluated the assembled materials and small-entity comments on issues related to elements of an IRFA. A copy of the full SBAR Panel Report is available in the rulemaking docket.
D. Unfunded Mandates Reform Act (UMRA)
This action does not contain an unfunded mandate of $100 million or more for state, local, or tribal governments as described in UMRA, 2 U.S.C. 1531 - 1538, and does not significantly or uniquely affect small governments. This action does contain unfunded Federal mandates under UMRA that may result in annual expenditures of $100 million or more for the private sector.  Accordingly, the costs and benefits associated with this action are discussed in Section IV.T of this preamble and in the RIA, which is in the docket for this rule.
E. Executive Order 13132: Federalism
This action does not have federalism implications. It will not have substantial direct effects on the states, on the relationship between the national government and the states, or on the distribution of power and responsibilities among the various levels of government.
F. Executive Order 13175: Consultation and Coordination with Indian Tribal Governments
This action has Tribal implications. However, it will neither impose substantial direct compliance costs on federally recognized Tribal governments, nor preempt Tribal law, and does not have substantial direct effects on the relationship between the Federal Government and Indian Tribes or on the distribution of power and responsibilities between the Federal Government and Indian Tribes, as specified in E.O. 13175. 65 FR 67249 (November 9, 2000). Consistent with the EPA Policy on Consultation and Coordination with Indian Tribes, the EPA will provide Tribal officials the opportunity to provide meaningful and timely input through government-to-government consultation during the development of this action. The majority of the facilities within Indian country expected to be affected by this proposed action are owned by private entities. For point sources, there would only be Tribal implications associated with this rulemaking in the case where a unit is owned by a Tribal government. The EPA notes that the reporting requirements for emissions data proposed are unlikely to impose substantial costs. For nonpoint sources, there would be Tribal implications for the proposed requirements for how Tribes should report nonpoint emissions when overlapping more than a single county within a state. Further, Tribal implications may exist for the proposed provision that directs states to include complete nonpoint source activity, inclusive of activity within Indian country, when tribes overlapping state boundaries are not required to report or optionally report nonpoint data to EPA.
G. Executive Order 13045: Protection of Children from Environmental Health and Safety Risks
The EPA interprets Executive Order 13045 as applying only to those regulatory actions that concern environmental health or safety risks that the EPA has reason to believe may disproportionately affect children, per the definition of "covered regulatory action" in section 2-202 of the Executive Order. This action is not subject to Executive Order 13045 because it does not concern an environmental health risk or safety risk.
H. Executive Order 13211: Actions Concerning Regulations That Significantly Affect Energy Supply, Distribution, or Use
This action is not a "significant energy action" because it is not likely to have a significant adverse effect on the supply, distribution or use of energy. Further, we have concluded that this action is not likely to have any adverse energy effects because the requirements to report emission data under this proposed action are either already being met as part of the current AERR or would be a small incremental impact on regulatory requirements for any facility required to report emission data under this action. The EPA does not anticipate that the provision described in section IV.D to collect daily fuel usage data from states for sources with intermittent electric generation would have any significant impact on the deployment of such sources.
I. National Technology Transfer and Advancement Act
This rulemaking does not involve technical standards.
J. Executive Order 12898: Federal Actions to Address Environmental Justice in Minority Populations and Low-Income Populations
Executive Order 12898 (59 FR 7629, February 16, 1994) directs federal agencies, to the greatest extent practicable and permitted by law, to make environmental justice part of their mission by identifying and addressing, as appropriate, disproportionately high and adverse human health or environmental effects of their programs, policies, and activities on communities with environmental justice concerns.
The EPA believes that this type of action does not concern human health or environmental conditions and, therefore, cannot be evaluated with respect to potentially disproportionate and adverse effects on communities with environmental justice concerns. This action would update reporting requirements for state, local, and tribal entities and add new reporting requirement for facilities for the collection of air emissions data that are used to inform EPA's technical analysis of impacts on human health and the environment.
K. Determinations Under CAA Section 307(b)(1) and (d)
Section 307(b)(1) of the CAA governs judicial review of final actions by the EPA. This section provides, in part, that petitions for review must be filed only in the United States Court of Appeals for the District of Columbia Circuit: (i) When the agency action consists of " any other nationally applicable regulations promulgated, or final action taken, by the Administrator," or (ii) when such action is locally or regionally applicable but "such action is based on a determination of nationwide scope or effect and if in taking such action the Administrator finds and publishes that such action is based on such a determination."  The CAA reserves to the EPA complete discretion to decide whether to invoke the exception in (ii) described in the preceding sentence.
This proposed action, if finalized, would be "nationally applicable" within the meaning of CAA Section 307(b)(1). In the alternative, to the extent a court finds the action to be locally or regionally applicable, the Administrator intends to exercise the complete discretion afforded to him under the CAA to make and publish a finding that the action is based on a determination of "nationwide scope or effect" within the meaning of CAA Section 307(b)(1).
This proposed action, if finalized, would implement a national emissions data collection program in all 50 states, the District of Columbia, U.S. territories, and Indian country, a geographic area that spans all 10 EPA regions and 12 Federal judicial circuits. The proposed action applies a uniform, nationwide approach to data collection and interpretation of the various CAA provision discussed in this preamble across all of these areas, and the proposed rule is based on a common core of legal, technical, and policy determinations (as explained in further detail in the following paragraph). For these reasons, this proposed action, if finalized, would be nationally applicable.
Alternatively, to the extent a court finds this proposal, if finalized, to be locally or regionally applicable, the Administrator intends to exercise the complete discretion afforded to him under the CAA to make and publish a finding that the action is based on one or more determinations of nationwide scope or effect for purposes of CAA Section 307(b)(1). Specifically, the proposed rule is based on a common core of statutory analysis, factual findings, and policy determinations concerning the collection of emissions data from state, local, and tribal agencies nationwide and from owners/operators of emission sources located in those states, territories, and Indian country. In addition, the technical, scientific, and engineering information in support of the proposed emissions data collection requirements relies on a nationally consistent modeling methodology to set emissions reporting thresholds, as set forth elsewhere in this proposed rule and in the relevant supporting documents in the docket for this proposed rule.
Therefore, pursuant to CAA Section 307(b), any petitions for review of this action, if and when it is finalized, must be filed in the D.C. Circuit within 60 days from the date such final action is published in the Federal Register.
In addition, pursuant to CAA Section 307(d)(1)(V), the EPA hereby determines that this rulemaking action is subject to the requirements of Section 307(d).
List of Subjects in 40 CFR Part 51
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Environmental Protection, Administrative practice and procedure, Air pollution control, Emission data, Intergovernmental relations, Criteria pollutants, Hazardous Air Pollutants, Ozone, Particulate matter, Oxides of Nitrogen, Sulfur dioxide, Lead, Regional haze, Reporting and record keeping requirements, Stationary sources, Mobile sources, Prescribed fires.

_____________________
Dated:

--------------------------------------------------------------------------------

____________________

Michael S. Regan,
Administrator.

For the reasons stated in the preamble, title 40, chapter I, Part 51 Subpart A of the Code of Federal Regulations is proposed to be amended as follows:
Subpart A -- Air Emissions Reporting Requirements
General Information for Inventory Preparers
§51.1  Who is responsible for what actions described in this subpart?
Both states and certain owners/operators of facilities emitting "air pollutants" (as defined by §51.50 of this subpart) are subject to requirements included in this section.
 Owners and operators of facilities.
 An owner/operator of a point source within a state's implementation planning authority must report emissions data as described by §51.25 of this subpart.
 An owner/operator of a point source that is outside the geographic scope of a state's implementation planning authority must report emissions data as described by §51.27 of this subpart. This could include owners/operators of facilities located within certain portions of Indian country, owners/operators of (1) deepwater ports subject to CAA requirements under the Deepwater Port Act, and (2) owners/operators of OCS sources as defined in CAA section 328(a) with the exception of owners/operators of facilities that are regulated under 43 U.S.C. §§1331 et seq. (the Outer Continental Shelf Lands Act) and that are located (a) offshore of the North Slope Borough of the State of Alaska, or (b) offshore of the United States Gulf Coast westward of longitude 87 degrees and 30 minutes.
 An owner/operator of a point source that collects source test data or performance evaluations may need to report that data as described by §§51.25 and 51.27 of this subpart.
 If the owner and operator of a facility are different parties, only one party needs to report under this subpart.
 An Indian tribe (as defined by CAA 302(r)) may elect to seek Treatment as State (TAS) status as prescribed by the Tribal Authority Rule 40 CFR Part 49, Subpart A. An Indian tribe may obtain approval to implement reporting for this subpart through a Tribal Implementation Plan (TIP), but Indian tribes are under no obligation to do so. Those Indian tribes that have obtained TAS status are subject to this subpart to the extent allowed in their TIP. Accordingly, for an Indian tribe that has applied for and received TAS status for air quality control purposes and is subject to the AERR under its TIP, the use of the term state in this subpart should be read to include that tribal government.
 State mandatory reporting.
 A state must collect and report to the EPA criteria pollutant and precursor emissions data from point sources (as defined by §51.50 of this subpart) as described by §51.15(a) of this subpart. A state must collect and report data for all such sources within the state's implementation planning authority, including any offshore areas within state waters or within any Federal waters for which a state agency has delegated authority. A lack of state permitting for point sources or pollutants associated with them does not exempt a facility or pollutant from being reported.
 A state must report to the EPA data from airports as described by §51.15(b) of this subpart.
 A state must report to the EPA rail yard data as described by §51.15(c) of this subpart.
 A state must report to the EPA nonpoint source data as described by §51.15(d) of this subpart.
 A state must report to the EPA mobile source data as described by §51.15(e) of this subpart.
 A state must report data about certain prescribed burning (as defined by 40 CFR §51.301) to the EPA (as described by §51.15(f) of this subpart) for those prescribed burns that meet the following criteria:
                 The prescribed burn is not an agricultural burn or a land clearance burn (as defined by §51.50 of this subpart); and
                 The prescribed burn occurs on state lands or military lands, excluding prescribed burns on such lands conducted by Federal Land Managers (as defined by CAA 302(i)); and
                 The prescribed burn is one of the following:
                    A broadcast burn or understory burn that impacts at least 50 acres; and/or
                    A pile burn that includes biomass from at least 25 acres; and/or
                    A prescribed burn that includes pile burning as well as other prescribed burn types that in total collects biomass from or burns at least 25 acres.
 EPA urges state environmental agencies to coordinate with state forestry agencies to collect, obtain, and report the data described by §51.1(c)(6). A lack of state permitting requirements or other planning processes does not exempt a prescribed burn from being reported.
 State optional reporting.
 For inventory years 2026 and later, a state that intends to collect and report hazardous air pollutants (HAP) on behalf of owners/operators for a given emissions inventory year must:
                    Promulgate a state regulation to collect facility inventory and actual annual emissions data for HAP to meet the requirements for owners/operators by:
 Replicating requirements on owners/operators from §51.5 of this subpart, excluding paragraphs §51.5(h) and (i);
 Ensuring the definition of point sources is consistent with §51.50 of this subpart; and
 Ensuring reporting of all HAP as described by §51.12(b) of this subpart and requirements for specific situations described by §51.12(d) and (e) of this subpart; and
 Ensuring reporting of incidental criteria pollutants and precursors as described by §51.12(c) of this subpart; and
 Including the timing for point source reporting from owners/operators to the state as described by §51.30 of this subpart;
 Ensuring reporting of all required data elements as described by §51.40(a) and (b) of this subpart; and
                    Apply to the EPA in writing by March 31[st] of the first inventory year for which the state intends to report emissions data for HAP (e.g., for the 2026 emissions inventory year, a state must apply by March 31, 2026) by providing citations to the state regulation for each of the elements listed in §51.1(d)(1)(i).
            The EPA will notify a state as expeditiously as possible regarding its application, any needed adjustments, and post final approval decisions on the EPA Air Emissions Inventories website for use by the state and owners/operators.
            A state must reapply for HAP reporting approval when one or more of the following events occurs:
 The state changes its emissions inventory reporting requirements related to any aspect of the application requirements described by §51.1(d)(1)(i) of this subpart.
 EPA revises requirements of this subpart for pollutants described by §51.12 (b) through (e) of this subpart, HAP reporting thresholds (for which the initial reporting thresholds are presented in Table 1B to Appendix A of this subpart) or the associated required data elements as described by §51.40.
 The EPA notifies a state in writing that a new application is required for any reason, including that the state failed to meet any requirement of this subpart.
 If a state intends to use or integrate with the Combined Air Emissions Reporting System (CAERS) for a particular inventory year, the state should notify the EPA of this intent by two months prior to start of the inventory year (e.g., for the 2024 inventory year, a state should notify the EPA by November 1, 2023).
 If a state intends to stop collecting and reporting HAP for point sources, the state must notify the EPA in writing by November 1st of the year prior to the inventory year (e.g., for the 2024 inventory year, a state must notify the EPA by November 1, 2023).
 The EPA approval for a state to report HAP remains effective for subsequent inventory years until the EPA revokes that approval and transfers responsibility back to owners/operators.
 The state (as defined by CAA 302(d)) may authorize a municipality (as defined by CAA 302(f)) to fulfill the data collection and reporting requirements of this subpart on behalf of the state and to submit data to the EPA for emissions within that municipality's authority. Such authorization does not relieve the state of responsibility for carrying out the applicable requirements of this subpart. Accordingly, for municipalities that have obtained authority to collect and report under this subpart, the use of the term "state" in this subpart should be read to include that municipality.
§51.5  What data, tools and other considerations apply for emissions reporting?
The requirements in this section are effective starting with different inventory years, as follows: Paragraphs (b) through (f) are effective starting with the 2026 inventory year. All other paragraphs are effective starting with the 2023 inventory year.
         A state or owner/operator must estimate annual actual emissions as defined in §51.50 of this subpart using the best available estimation methods for assessing whether its facility emissions exceed the emissions reporting thresholds in Tables 1A and 1B to Appendix A of this subpart and for submitting point source emissions data under this subpart. The "Introduction to the EPA Compilation of Air Pollutant Emissions Factors (AP-42)" describes many techniques for calculating emissions and provides on page 4 a hierarchy of emissions estimation methods. For the purposes of this subpart, a state or owner/operator should preferentially use available emissions calculation methods at the top of the hierarchy over emissions calculation approaches lower in the hierarchy. Where current the EPA guidance materials are outdated or are not applicable to sources or source categories, an owner/operator (other than a small entity, as defined by §51.50 of this subpart) should develop and document new techniques for estimating emissions, which should rely on any available source measurements applicable to the emissions source(s).
         A state or owner/operator must include emissions from mobile sources (excluding aircraft and ground support equipment) operating primarily within the facility site boundaries of a point source or multiple adjacent point sources when assessing whether its facility emissions exceed the emissions reporting thresholds in Tables 1A and 1B to Appendix A of this subpart and when submitting point source emissions data under this subpart.
         An owner/operator submitting emissions data directly to the EPA under this subpart must use continuous monitor data applicable to the units and processes that operated during the reporting year to calculate annual actual emissions. In the absence of monitored data, an owner/operator must use the most recent source test(s) applicable to the operating conditions of the units and processes during that year to estimate annual actual emissions. An owner/operator should determine which source test data should be included to best estimate annual actual emissions. If a facility has source tests, performance evaluations, or continuous emissions monitoring data for a unit or process that operated during the reporting year and the owner/operator does not use that data to estimate annual emissions, then the owner/operator must submit a justification for that choice for each unit and pollutant for which such data are not used to estimate emissions.
         A state submitting point source emissions on behalf of owners/operators under this subpart must ensure that owners/operators of facilities submitting data to the state take the same approaches as described in paragraph §51.5(a) through (c) of this subpart. If a state submits data for an owner/operator who has not used available source test data or continuous monitor data to estimate emissions, then the state must submit a justification for each unit and pollutant for which such data are not used to estimate emissions.
         When source tests, performance tests, or continuous emissions monitor data are not available, a state and owner/operator may use emission rates from the EPA compilations of emission factors such as WebFIRE and AP-42 to estimate emissions. An owner/operator may also use emission factors provided by states. To estimate emissions from point sources, a state or owner/operator should use emission factors that represent the emissions process and controls at the facility. If existing emission factors are insufficient for developing representative annual actual emissions, a state or owner/operator (other than a small entity, as defined by §51.50 of this subpart) should develop new emission factors through emission testing of point sources when existing EPA source test methods are available.
         When data described in paragraphs (c), (d), and (e) are not available, a state or owner/operator may use the SPECIATE database or other credible, publicly available speciation profile data to calculate ratios of related pollutants if relevant speciation profiles are available. Starting with the 2026 inventory year, when using a speciation profile, a state or owner/operator must provide the speciation profile code with their data. When estimating emissions using speciation data, the emissions data must include:
 The most applicable emissions calculation method indicating the type of speciation profile used;
 The speciation factor used in the calculation, reported as the emission factor;
 The pollutant code that identifies the pollutant used to calculate another pollutant, reported as the denominator of the emission factor;
 The pollutant code that identifies the pollutant calculated from the speciation profile, reported as the numerator of the emission factor;
 The emissions value and associated required data elements for the pollutant identified in §51.5(f)(3), reported as an annual emissions value even if that pollutant is not otherwise required (e.g., Total organic gases); and
 In the case of a SPECIATE profile, the profile code reported as the emission factor comment, or in the case of other speciation profiles, the journal citation or reference to a publicly available report reported as the emission factor comment.
         A state must report data using the Emissions Inventory System (EIS) or analogous electronic reporting approach provided by the EPA to report data required by this subpart. Submission to the EIS can be done using EPA's Central Data Exchange (CDX). Unless otherwise noted in this section, the EPA provides states information about reporting data, required and optional data fields, and explains how to access all data needed for reporting to EIS as part of a NEI plan available at https://epa.gov/air-emissions-inventories/national-emissions-inventory-nei.
         An owner/operator reporting directly to the EPA under this subpart must use the Combined Air Emissions Reporting System (CAERS) or analogous electric reporting approach provided by the EPA to report emissions data. The EPA provides owners/operators information about reporting data, required and optional data fields, and explains how to access to all data needed for reporting with CAERS at https://epa.gov/air-emissions-inventories.
         An owner/operator reporting directly to the EPA under this subpart must use the Compliance and Emissions Data Reporting Interface (CEDRI) to report source test data and performance reports as required by §51.25 and §51.27 or use an analogous electronic reporting approach provided by the EPA. CEDRI can be accessed through the CDX.[4] CEDRI works with the EPA's Electronic Reporting Tool (ERT) available from EPA's ERT website (https://epa.gov/electronic-reporting-air-emissions/electronic-reporting-tool-ert). A list of test methods, performance evaluations, and pollutants compatible with the Electronic Reporting Tool (ERT), as well as the date on which those methods or performance evaluations were available on the ERT, is available from the EPA via the ERT website https://epa.gov/system/files/documents/2021-09/ert-compatible-methods-and-pollutants.pdf).
         A state or owner/operator of point sources reporting under this subpart must use the most current data reporting codes for electronic reporting that are available at the time of reporting. Reporting codes can change over time, and the EPA will strive to publish the EIS reporting codes that can be used for each inventory year by June 30[th] of inventory year. For example, the EPA would plan to publish by June 30, 2024 codes that are to be used for reporting 2024 emissions. Codes are published by the EPA as follows:
 Source classification codes (SCCs) can be obtained from the EPA SCC website (https://epa.gov/scc). Materials provided on this website explain what to do if a SCC is not available for an emissions process; and
 Other reporting codes are available through EPA's electronic reporting data systems (e.g., EIS and CAERS), and the EPA may make them available through references within the NEI plan for each inventory year.
         The EPA provides states for their use nonpoint emissions calculation methods, associated tools/spreadsheets, and draft activity and emissions data for nonpoint sources, point source aircraft, and point source rail yards. The nonpoint information includes approaches and data based on county totals for commercial marine vessels that are treated in this subpart as nonpoint sources for reporting purposes. The EPA provides on its Air Emissions Inventories website (https:/epa.gov/air-emissions-inventories) an NEI Plan that includes directions for which methods, tools, and models should be used and instructions for accessing data described in this paragraph.
         The EPA provides the MOtor Vehicle Emissions Simulator (MOVES) model including quality assurance tools for input data at the MOVES website (https://epa.gov/moves). The EPA also provides draft and final onroad and nonroad emissions data based on the MOVES model. States, except for California, must use MOVES model input formats and the quality assurance tools or the same for the latest available on-road and nonroad EPA models to meet the requirements of §51.15(e). The model version to be used for a given inventory reporting year will be defined in an emissions inventory plan as per paragraph (k).
         For onroad mobile sources, the EPA approves onroad mobile models for California for transportation conformity purposes and for use in State Implementation Plans (SIPs). For this subpart, California must report emissions from onroad mobile sources using the latest model version approved by the EPA as of January 1[st] of the emissions inventory year and may optionally use a newer approved model. For example, the onroad model approved as of January 1[st], 2023 should be used to estimate and report emissions to meet the requirements in §51.15(e)(3) for the 2023 reporting year, or the state could optionally choose to use a model approved by the EPA after that date.
         Confidential data / Confidential Business Information (CBI). Emissions data are defined by 40 CFR 2.301(a)(2)(i) and are not confidential pursuant to 42 USC 7414(c). The specific data elements submitted under this subpart all fall within the definition of emissions data and are therefore not entitled to confidential treatment. Further, pursuant to 42 USC 7414(c), the EPA is required to make emissions data available to the public. Thus, all data elements submitted under this subpart will not be protected as CBI and will be made publicly available without further notice to states or the owner/operator of facilities.
         An owner operator or state reporting on their behalf must consider the recommendations and requirements of paragraphs (a) through (f), (n), (q), and (r) of this section when:
 Estimating emissions to determine whether a facility's annual actual emissions of HAP exceed point source reporting thresholds in Table 1B to Appendix A of this subpart; and
 When estimating emissions to report to EPA.
         To estimate emissions for pollutant groups (e.g., "Lead and compounds" or "Nickel and compounds"), an owner/operator or a state reporting on their behalf should ensure emissions values accurately reflect the mass of the metal/toxic portion of the group (Lead or Nickel in these examples) by:
 Using emission factors or source test emission rates without any adjustments; or
 Accounting for chemical compounds to reflect only the toxic portion of the pollutant group when estimating emissions based on material balance or engineering judgement; or
 When no other information is available, assuming the entire mass of the HAP reported is the toxic portion.
         Some HAP may be measured or have emission factors for a pollutant group as well as for individual compounds within the group. An owner/operator or a state reporting on their behalf must report the most detailed pollutants available preferentially over pollutant groups. When the detailed pollutants do not comprise the total mass of the pollutant group, the remaining portion of mass for the pollutant group must be reported as implemented in the electronic reporting approach (as described by §51.5(g)). Specific compound groups and individual pollutants are provided in Tables 1B and 1D to Appendix A of this subpart.
§51.10  What criteria determine when facilities must be reported as point sources?
 For point sources (as defined by §51.50 of this subpart), when determining whether emissions data from a facility must be report as a point source, states and owners/operators must:
 Include total annual actual emissions from all stack and fugitive release points at the facility; and
 Include emissions from mobile sources as described by §51.5(b) of this subpart, and in doing so, may exclude emissions from aircraft and ground support equipment occuring at the facility.
 For point sources associated with emission inventories required by Part 51 Subpart G, Subpart X, Subpart Z, Subpart AA, Subpart CC, states must interpret the definition of point sources (as per §51.50 of this subpart) as follows:
 Use only the criteria of Table 1A to Appendix A of this subpart in assessing the definition;
 For Subpart G, the reporting threshold applies for oxides of nitrogen (NOX);
 For Subparts X, AA, and CC, the reporting thresholds apply for NOX, carbon monoxide (CO), and volatile organic compounds (VOC); and
 For Subpart Z, the reporting thresholds apply for NOx, CO, VOC, sulfur dioxide (SO2), ammonia (NH3), total particulate matter whose aerodynamic diameter is 2.5 microns or less (PM2.5), and total particulate matter whose aerodynamic diameter is 10 microns or less (PM10).
 If EPA finalizes revisions to any HAP reporting thresholds presented in Table 1B to Appendix A of this subpart, only those revised reporting thresholds published in the Federal Register at least 6 months before the start of an inventory year apply for that inventory year (e.g., revised thresholds finalized by June 30, 2026 would apply for the 2026 emissions reports).
 To develop new HAP reporting thresholds for revisions of this subpart, the EPA would apply the following formula for changes to UREs: Revised reporting threshold = (Initial threshold in Table 1B to Appendix A of this subpart x URE in 2022) / Revised URE; and
 To develop new HAP reporting thresholds for revisions of this subpart, the EPA would apply the following formula for changes to RfCs: Revised reporting threshold = (Initial threshold in Table 1B to Appendix A of this subpart x Revised RfC) / RfC in 2022.
§51.12  What pollutants must be reported for point sources?
 Criteria air pollutants and precursors. For the purposes of reporting emissions data for this subpart, criteria pollutants and precursors are CO, NOX, VOC, SO2, NH3, total PM2.5, total PM10, Pb, and either condensable PM (when emitted by the facility), or filterable PM2.5. When the facility potential to emit of any such pollutant is greater than or equal to the reporting thresholds listed in Table 1A to Appendix A of this subpart, all such pollutants must be reported.
 Hazardous air pollutants.
 For major point sources, reported HAP must include all HAP as listed in Section 112(b)(1) of the Clean Air Act, 42 U.S.C. 7412(b)(1), and 40 CFR 63.64(a).
 For point sources other than major sources, reported HAP must include any pollutant listed in Table 1B to Appendix A of this subpart when the annual actual emissions of that pollutant or pollutant group is greater than or equal to the HAP reporting threshold (presented in Table 1B to Appendix A of this subpart).
 Incidental criteria air pollutants or precursors. If a facility meets the point source definition of §51.50 because of the facility HAP emissions but does have PTE or actual emissions of criteria pollutants or precursors exceeding the reporting thresholds of Table 1A to Appendix A of this subpart, emission reports for that facility must include incidental criteria pollutants or precursors as listed in the "Associated CAPs" columns Tables 1B and 1D to Appendix A of this subpart.
Specific Reporting Requirements for State Reporters
§51.15  What data does my state need to report to EPA?
State annual and triennial requirements are included in paragraphs (a) through (f) of this section, with the first inventory year for each requirement included in §51.20. At a state's option, a state may report other emissions data described by paragraphs (g) through (i) of this section. Requirements on a state for inventories required by 40 CFR Subparts G, X, Z, AA, and ZZ are included at paragraph (j) of this section.
 Point sources.
 A state must report the facility inventory and annual actual emissions of all criteria pollutants and precursors as described by §51.12(a).
 If the EPA has approved a HAP reporting application as per §51.1(d)(2) of this subpart, a state must report emissions of HAP consistent with §51.12(b) and (c) of this subpart. A state may report one or more HAP voluntarily through the 2025 inventory year and may not report HAP without an approved application starting with the 2026 inventory year.
 Starting with the 2026 inventory year, a state must report the facility inventory and daily fuel consumption and associated required data elements as described in §51.40 for small generating units when:
 Hourly or daily emissions and activity data from the unit are not otherwise reported to the EPA, and
 The unit was operated to offset electricity demand from the electricity grid; and
 The unit is located at a facility that operates on land.
 for electricity generation to offset electricity demand from the electricity grid. A state need not include any units in their report when an owner/operator has reported daily or hourly emissions or activity data directly to the EPA. The unit is located at a facility that operates on land.
 A state may report additional pollutants not required by §51.12 of this subpart when supported by the EPA electronic reporting approaches (as described by §§51.5(g) and (h) of this subpart).
 A state must report point source data consistent with the required data elements described by §51.40 of this subpart.
 Airports. Airport data includes emissions from aircraft that occur lower than 3,000 feet above the ground surface (the typical height considered to be part of the take-off or landing cycle) and emissions from ground support equipment (GSE). A state must report stationary sources and qualifying mobile sources as defined by §51.5(b) (other than aircraft and GSE) at airports as part of §51.15(a) and report aircraft and GSE data for triennial inventory years for all airports within a state's implementation planning authority:
 A state must submit activity data (i.e., landings and takeoffs).
 In lieu of submitting aircraft activity data required by §51.15(b)(1), a state may instead review EPA-provided data as described in §51.5(k) of this subpart, submit comments on that data, and/or notify the agency that the state accepts these data.
 In addition to §51.15(b)(1) or (2), a state may voluntarily submit annual actual emissions of aircraft and GSE for some or all airports. If submitting annual actual emissions, a state must:
 Use the latest aircraft emissions model specified by the NEI plan (as described by §51.5(k) of this subpart);
 Submit all pollutants estimated by the latest aircraft emissions model;
 Submit documentation that describes how the state used the aircraft emissions model to estimate annual actual emissions and quality assured the data; and
 Report aircraft data consistent with the required data elements described by §51.40 of this subpart.
 Rail yards. Rail yard data include emissions from yard locomotive switchers and can include other emissions sources if present. For triennial inventory years for all rail yards within a state's implementation planning authority:
 A state must submit activity data and documentation that explains how the state collected or created the data.
 In lieu of submitting rail yard activity data and documentation required by §51.15(c)(1), a state may instead review EPA-provided data as described in §51.5(k) of this subpart, submit comments on that data, and/or notify the EPA that the state accept these values.
 In addition to §51.15(c)(1) or (2), a state may voluntarily submit annual actual emissions for some or all rail yards. If submitting annual actual emissions, a state must:
 Submit all pollutants estimated by the EPA rail yard emissions method;
 Submit documentation that describes how the state estimated rail yard annual actual emissions and quality assured the data; and
 Report rail yard data consistent with the required data elements described by §51.40 of this subpart.
 Nonpoint sources. For triennial inventory years, a state must report nonpoint sources, including information for all stationary source emissions not reported as point sources. For reporting purposes, nonpoint sources include commercial marine vessels and underway locomotives.
 For this section, "tool" refers to any calculation tool, spreadsheet, or other electronic instrument provided by the EPA for the purpose of nonpoint source emission calculations.
 A state must complete an online survey in the electronic reporting approach described in §51.5(g) to indicate by source classification code (SCC) for which nonpoint sources a state will report nonpoint tool input data, accept EPA-provided tool input data, and/or report annual actual emissions.
 For nonpoint sources with EPA-provided emissions calculation tools (as described by §51.5(k)), excluding commercial marine vessels and locomotives:
 A state must report input data for the nonpoint tools in the formats provided by EPA; or
 In lieu of submitting tool inputs, a state may review and accept EPA-provided nonpoint tool input data; and
 In addition to §51.15(d)(3)(i) or (ii), a state may voluntarily submit annual actual emissions of any pollutants allowed by the electronic reporting approach (as described by §51.5(g)).
 For commercial marine vessels and locomotives, a state must either:
 Report annual actual emissions of pollutants described by §51.12(a); or
 Provide comment on EPA-provided annual actual emissions data; or
 Accept EPA-provided emissions data.
 For nonpoint sources without the EPA tools:
 A state must report annual actual emissions of pollutants described by §51.12(a) of this subpart if the nonpoint source is not excluded by paragraphs (6) and (8) of this section.
 A state may report emissions of HAP listed in Table 1B.
 For actual annual emissions reported under §51.15(d) paragraphs (3) through (5) of this subpart, a state must submit documentation that describes how the state estimated nonpoint annual actual emissions and quality assured the data.
 A state should exclude episodic wind-generated emissions from sources that are not point sources and exclude biogenic sources of emissions from vegetation and soils.
 A state may exclude nonpoint sources when such sources are reasonably estimated by the state to represent a de minimus percentage of total county and state emissions of a given pollutant.
 The EPA nonpoint tools include input data for the entire area within county boundaries and state waters, including any Indian country. For paragraphs (3) through (6) of this section, a state must either:
 Include total activity input (inclusive of Indian country) when reporting nonpoint emissions; or
 For a state that includes counties overlapping Indian country for an Indian tribe expected to report emissions as per §51.1(b), the state must avoid double counting by excluding the activity within and emissions from Indian country from the county total data reported.
 An Indian tribe that reports nonpoint tool inputs and/or emissions to meet the requirements of paragraphs (3) through (7) of this section must report that data separately for each county that includes Indian country. When an Indian tribe reports nonpoint emissions, the EPA encourages the tribe to coordinate with the state(s) and to use EPA-provided tools and include documentation with their submissions.
 Onroad mobile and nonroad mobile sources. For triennial inventory years, a state must report onroad mobile and nonroad mobile data and include information for all onroad and nonroad categories included in the EPA mobile emissions model, such as the MOVES model.
 A state must provide model inputs to the EPA model. A state must include at a minimum:
 A county database checklist;
 Vehicle miles travelled (by county and road type); and
                  Vehicle population (by county, vehicle type, fuel type and age).
 If a state has relevant data for the inventory year, a state may optionally provide inputs to the latest EPA-developed mobile emissions model for the following:
 Hourly average speed distribution by vehicle type, ideally different for weekday and weekend (distance traveled in miles divided by the time in hours);
 Vehicle age distribution;
 Inspection and maintenance program information; and
 Documentation that describes how the state created these inputs and quality assured the data.
 In lieu of submitting model inputs for onroad and nonroad mobile sources, California:
 Must submit emissions values for the same pollutants estimates by the EPA model for criteria pollutants and precursors;
 Must submit documentation that describes the model inputs, use of the model and any options selected, post-processing steps, and the quality assurance performed to estimate the emissions; and
 May submit emissions of HAP, greenhouse gases, and other pollutants. The EPA urges California to include these other pollutants when they are estimated by the EPA onroad and nonroad model.
 Must submit data consistent with the required data elements described by §51.40 of this subpart.
 In lieu of submitting any data, states other than California may review and accept EPA-provided model inputs and emission estimates. Such states must use the electronic reporting approach provided by the EPA (as described by §51.5(g) of this subpart).
 Prescribed fires other than agricultural burning or land clearance burning. A state must annually report data for any prescribed burn other than an agricultural burn or land clearance burn that meets the criteria described by §51.1(c)(6) of this subpart. The EPA urges states to coordinate between state environmental agencies and forestry agencies, and forestry agencies may submit for the state.
 A state must report data consistent with the required and optional data elements described by §51.40 and Table 3 to Appendix A of this subpart and other optional data fields as provided by the EPA through reporting format instructions.
 For burns that are a combination of broadcast or understory burns and pile burns, a state must submit separate entries for the broadcast or understory portion of the burn and for the pile burn.
 Wildfires. A state may report wildfire timing and activity data using the data elements described by §51.40 of this subpart. A state may review and submit comments about EPA-provided emissions and activity data. The EPA urges states to coordinate between state environmental agencies and forestry agencies, and forestry agencies may submit for the state.
 Agricultural Fires. A state may report agricultural fire timing and activity data using the data elements described by §51.40(f) of this subpart. A state may review and submit comments about EPA-provided emissions and activity data.
 A state may submit sub-annual data to EPA.
 A state may choose to report NOX and VOC summer day emissions as required by the ozone SIP requirements rules (40 CFR Subparts, X, AA, or CC) or report CO winter work weekday emissions for CO nonattainment areas or CO attainment areas with maintenance plans to the EIS using the data elements described in this subpart.
 A state may choose to report ozone season day emissions of NOX as required under the NOX SIP Call and summer day emissions of NOX that may be required under the NOX SIP Call (40 CFR 51.122) for controlled sources to the EIS using the data elements described in this subpart.
 A state may choose to report average day emissions of any pollutants submitted under the PM2.5 SIP Requirements Rule (40 CFR Subpart Z) to the EIS using the data elements described in this subpart.
 Inventory requirements for State Implementation Plans required under Part 51 Subparts G, X, Z, AA, and CC. The following paragraphs provide specifications that define how a state shall be consistent with the data elements required as per 40 CFR §51.122(g), §51.915, §51.1008 (a)(1)(vi), §51.1115(e), and §51.1315(e).
 Point sources, aircraft and GSE, and railyards. A state must:
 Report sources as point sources as defined by §51.50 of this subpart;
 Meet the requirements of §51.15(a)(1), limiting reports to those pollutants required by the SIP; and
 Compile point source data consistent with the required data elements described by §51.40 of this subpart.
 Nonpoint sources. A state must:
 Compile emissions for pollutants required for the SIP using the required data elements as described by §51.40 of this subpart; and
 Include any airports (including aircraft and GSE) not reported as a point source; commercial marine vessels, locomotives, agricultural burning, prescribed burning, and wildfires; and
 Include all sources of emissions (including biogenic and geogenic sources) allowing for the provision of §51.15(d)(8) of this subpart; and
 Meet the requirements related to adjacent state land and Indian country of §51.15(d) paragraphs (9) and (10) of this subpart when Indian country is within a nonattainment area.
 Onroad and nonroad. A state must:
 Compile emissions for pollutants required for the SIP rather than model input data using the required data elements as described in §51.40 of this subpart; and
 Meet the requirements related to adjacent state land and Indian country described by §51.15(d) paragraphs (9) and (10) of this subpart when Indian country is within a nonattainment area. While §51.15(d) paragraphs (9) and (10) are for nonpoint sources for the triennial reporting requirement under this subpart, they apply to onroad and nonroad sources for the purposes of this paragraph.
 Supporting information. A state must report the data elements in Tables 2A and 2B to Appendix A of this subpart and other data required for use of EPA's electronic reporting approach (as described by §51.5(g)). The EPA may ask states to report other data or documentation as needed to meet special purposes.
 Quality assurance and supporting information. In addition to the required reporting and documentation described in paragraphs (a) through (k) of this section, the EPA may ask states to review or revise data concerns identified through EPA quality assurance. The EPA may ask states for other data or documentation to support a state submission when the information provided does not fully explain the source or quality of the data. Based on the EPA quality review, the EPA may elect not to use the state-provided data if it does not pass quality assurance checks or if the state's documentation does not adequately explain the origin and quality of the submitted data.
§51.20  When does my state report which information to EPA?
A state is required to report both annual and triennial emission inventories to the EPA. The content of these inventories may vary depending on the inventory year and choices made by a state in accordance with the provisions of §51.1(d).
 Annual inventory.
 For the 2023 through 2026 inventory years, a state must report data for point sources to the EPA (as defined by §51.15(a) of this subpart) within 12 months and 15 days of the end of the inventory year (e.g., for the 2022 inventory year, by January 15[th], 2024). For 2023 through 2025, this requirement excludes reporting of data for small generating units consistent with the requirements of §51.15(a)(3) of this subpart.
 Starting with the 2026 inventory year, a state is required to report prescribed fire data (except for agricultural burning and land clearance burning, as described by §51.15 (f)) within 6 months after the end of the inventory year. For example, 2026 data will be due by July 1[st], 2027 and then every July 1[st] thereafter. Prior to the 2026 inventory year, a state may report prescribed burning data or review EPA-provided data within 6 months after the end of the inventory year.
 A state may report wildfire and agricultural burning data or review EPA-provided data as identified in §51.15 (g) and (h) by the same deadline of §51.20(a)(2).
 For the 2027 through 2029 inventory years, a state must report point source data to the EPA (as described by §51.15(a) of this subpart) within 9 months after the end of the inventory year (e.g., for the 2027 inventory year, by September 30[th], 2028).
 Starting with the 2030 inventory year and for every inventory year thereafter, a state must report point source data to the EPA (as described by §51.15(a) of this subpart) within 5 months after the end of the inventory year (e.g., for the 2030 inventory year, by May 31[st], 2031).
 Triennial inventory. In addition to the annual inventory requirements of §51.20(a) of this subpart, a state must report additional data starting with the 2023 inventory year and every triennial year thereafter (2026, 2029, etc.) by the dates provided below.
 A state must report airport data (as described by §51.15 (b) of this subpart) within 9 months after the inventory year, or 60 calendar days after the EPA provides airport data to a state, whichever is later (i.e., for the 2023 inventory year, by September 30[th], 2024, or later).
 A state must report data within 12 months and 15 days after the end of the inventory year (i.e., for the 2023 inventory year, by January 15[th], 2025) for:
 Rail yard sources (as described by §51.15 (c) of this subpart);
 Onroad and nonroad sources (as described by §51.15 (e) of this subpart); and
 Nonpoint emissions for sources without EPA tools (as described by §51.15(d)(5) of this subpart).
 A state must submit an online nonpoint survey (as described by §51.15(d)(2) of this subpart) within 15 months after the end of the inventory year (i.e., for the 2023 inventory year, by March 31[st], 2025).
 A state must submit nonpoint tool inputs (as described by §51.15(d)(3) of this subpart), within 30 days of the EPA providing tool inputs to the state, or within the period defined by the EPA at the time the tool inputs are provided, whichever is longer.
 When a state optionally provides nonpoint emissions for nonpoint sources with EPA tools (as described by §51.15(d)(3)(iii) of this subpart), a state must report such data and documentation (as described by §51.15(d)(6) of this subpart) within 60 days of the EPA providing tool inputs to the state, or within the period defined by the EPA at the time the tool inputs are provided, whichever is longer.
Specific Reporting Requirements for Owners and Operators of Facilities
§51.25  What data do owners or operators of facilities within states need to report to EPA?
 An owner/operator of a facility within a state must report the facility inventory and annual actual emissions of HAP consistent with §51.5 provisions of this subpart for owners/operators, §51.12(b) and (c) of this subpart, and associated required data elements (as described by §51.40 of this subpart) if:
 The facility is in a state that does not have an approved application (as per §51.1(d)(1) of this subpart); and
 The facility is a point source as defined by §51.50 of this subpart.
 An owner/operator of a point source must report results of source tests and performance evaluations if:
 Such results are not otherwise reported to the EPA based on regulations listed at https://epa.gov/electronic-reporting-air-emissions/cedri#list;
 Such results are gathered to meet any other federal or state requirement;
 Such results are supported by an EPA electronic reporting system at the time the test conducted as described in §51.35 of this subpart; and
 The tests are not subject to confidential treatment in accordance with exceptions for emission data provided by 40 CFR §2.301 subparagraphs (a)(2)(ii)(A) and (a)(2)(ii)(B).
 Quality assurance and supporting information. The EPA may require an owner/operator of a point source to review and/or revise data that do not meet quality assurance criteria. The EPA may require an owner/operator of a point source to provide other data or documentation to support their submissions when information provided does not fully explain the source or quality of the data provided.
§51.27  What data do owners or operators of other facilities need to report to EPA?
 An owner/operator of a point source outside the geographic scope of a states' implementation planning authority is subject to the requirements of §51.25(b) and (c) of this subpart.
 An owner/operator of a point source outside the geographic scope of a states' implementation planning authority must:
 Report the facility inventory and annual actual emissions of criteria pollutants, precursors, and HAP consistent with §51.5 provisions for owners/operators, §51.12(a) through (c) of this subpart and associated required data elements as described in §51.40 of this subpart;
 Report the facility inventory and daily fuel consumption and associated required data elements as described in §51.40 for small generating units when:
 Hourly or daily emissions and activity data from the unit are not otherwise reported to the EPA, and
 The unit was operated to offset electricity demand from the electricity grid; and
 The unit is located at a facility that operates on land.
 For portable facilities operating across state and/or Indian country boundaries, report the facility inventory and the portion of annual emissions not reported by those states and/or tribes.
 For owners/operators of offshore facilities subject to title V emissions reporting and/or emissions quantification requirements, owners/operators should use approaches consistent with those permits to identify the emissions sources of such facilities and to estimate and submit emissions data.
 An owner/operator of a facility subject to the requirements of 40 CFR §49.138 that also meets the point source definition of this subpart is still required to report in accordance with this subpart except that such facilities:
 Are exempt from the requirements of this subpart to report emissions of those pollutants which are reported under 40 CFR §49.138, and
 May at the option of the owner/operator, report those exempt pollutants to the EPA electronic reporting system described in §51.5(h) of this subpart.
§51.30  When do owners or operators of facilities need to report data to EPA?
 Optional reporting for 2024 and 2025. For the 2024 and 2025 emissions inventory years, an owner/operator of a point source has the option to complete submission of data in accordance with §51.25(a) and §51.27(b) through (d) of this subpart within 6 months after the end of the inventory year. The first date for meeting this optional reporting approach is May 31, 2025 for the 2024 inventory year.
 Mandatory reporting for 2025. For the 2025 emissions inventory year, an owner/operator of a point source within Indian country must complete submission of data in accordance with §51.25(a) and §51.27(b) through (d) of this subpart by May 31[st], 2026.
 Mandatory reporting for 2026. For the 2026 emissions inventory year, an owner/operator of a point source reporting under this subpart directly to the EPA must complete submission of data required by §51.25(a) and §51.27(b) through (d) of this subpart by May 31[st], 2027.
 Mandatory reporting for 2027 and subsequent years. Starting with the 2027 emissions inventory year and every year thereafter, an owner/operator of a point source reporting under this subpart directly to the EPA must complete submission of data required by §51.25(a) and §51.27(b) through (d) of this subpart within 3 months after the inventory year. The first date for meeting this requirement is March 31, 2028 for the 2027 inventory year.
 Owners/operators conducting performance tests and performance evaluations that meet the requirements of §51.25(b) of this subpart must report results from all such tests electronically to the EPA using approaches required by §51.35 of this subpart. Test results conducted on and after [insert effective date of the final rule in the Federal Register] must be reported by:
 The earliest scheduled reporting date for any form of reporting (electronic or otherwise) as required by the federal or state action motivating the measurements; or
 If no scheduled date exists, within 60 days of completing the measurements.
§51.35  How do owners or operators of a facility report emissions, source test, and performance evaluation results?
For purposes of this section, the terms ERT and CEDRI mean ERT and CEDRI or analogous electronic reporting approaches provided by the EPA, as per §51.5(i).
 Performance Tests and Performance Evaluations. Owners or operators of facilities must submit performance test and performance evaluation data following the procedures specified in paragraphs (a)(1) through (a)(3) of this section. Section §51.5(i) of this subpart provides more information on ERT and a list of test methods, performance evaluations, and pollutants supported.
 Performance Test Methods that are supported by the ERT as listed on the ERT website at the time the test is conducted. Upload the ERT project data file or an electronic file consistent with the XML schema with the appropriate data to CEDRI as a Part 51 submission.
 Performance Evaluations of CEMS measuring relative accuracy test audit (RATA) pollutants that are supported by the ERT as listed on the ERT website at the time the evaluation is conducted. Submit the results of the performance evaluation to the EPA via CEDRI. Submit the data in a file format generated using the ERT. Alternatively, submit an electronic file consistent with the XML schema listed on the ERT website.
 Performance Test Methods or Performance Evaluations that are not supported by the ERT as listed on EPA's ERT website at the time of the test or evaluation is conducted. The results of the performance test method or performance evaluation must be included as an attachment (such as a Portable Document Format (PDF) file) in the ERT or an alternate electronic file consistent with the XML schema listed on EPA's ERT website. Submit the ERT-generated package or alternate file to the EPA via CEDRI.
 Performance Test and Performance Evaluation Submission Content. In addition to the data required to be submitted in §51.35(a) of this subpart, unless otherwise approved by the Administrator in writing, submit the following elements identified in paragraphs (b)(1) through (11) of this section. If the elements are not already included as part of the performance test method or performance evaluation, put these elements in an attachment (such as a PDF file) in the ERT or an alternate electronic file consistent with the XML schema listed on EPA's ERT website. Submit the ERT-generated package or alternate file to the EPA using CEDRI.
          The capacity of the unit being tested.
          The load of the unit, in terms of percent capacity, during the testing period.
          The level of activity of the unit during the testing period (e.g., input consumption rate, product consumption, heat input, and/or output production rate).
          The operating conditions of the unit during the testing period.
          The process data, such as temperatures, flow rates, pressure differentials, pertaining to the unit and its control devices during the testing period.
          General identification information for the facility including a mailing address, the physical address, the owner or operator or responsible official (where applicable) and his/her email address, and the appropriate Federal Registry System (FRS) number for the facility.
          Purpose of the test or evaluation including the applicable regulation requiring the test (if any), the pollutant(s) and other parameters being measured, the applicable emission standard (if any), any process parameter component, and a brief process description.
          Description of the emission unit undergoing testing or evaluation including fuel burned, control devices, and vent characteristics; the appropriate source classification code (SCC); the permitted maximum process rate (where applicable); and the sampling location.
          Description of sampling or evaluation and analysis procedures used and any modifications to standard procedures, quality assurance procedures and results, record of process operating conditions that demonstrate the applicable test or evaluation conditions are met, and values for any operating parameters for which limits were being set during the test or evaluation, as applicable.
          Where a performance test method or performance evaluation requires you to record or report, the following shall be included in your submission: Record of preparation of standards, record of calibrations, raw data sheets for field sampling, raw data sheets for field and laboratory analyses, chain-of-custody documentation, and example calculations for reported results.
          Identification of the company conducting the performance test or evaluation including the company's primary office address, telephone number, email address, and the name of the company employee who conducted the test.
  Extensions for CDX / CEDRI Outages. If you are required to electronically submit a report through CEDRI in the CDX, you may assert a claim of an EPA system outage for failure to timely comply with that reporting requirement. To assert a claim of an EPA system outage, you must meet the requirements outlined in paragraphs (c)(1) through (5) of this section. The decision to accept the claim of an EPA system outage and allow an extension to the reporting deadline is solely within the discretion of the Administrator.
      (1) You must have been or will be precluded from accessing CEDRI and submitting a required report within the time prescribed due to an outage of either the CEDRI or CDX systems.
      (2) The outage must have occurred within the period beginning five business days prior to the date that the submission is due. The outage may be planned or unplanned.
      (3) You must submit notification to the Administrator in writing as soon as possible following the date you first knew, or through due diligence should have known, that the event may cause or has caused a delay in reporting.
      (4) You must provide to the Administrator a written description identifying:
            (i) The date(s) and time(s) when CDX or CEDRI was accessed, and the system was unavailable;
            (ii) A rationale for attributing the delay in reporting beyond the regulatory deadline to an EPA system outage;
            (iii) A description of measures taken or to be taken to minimize the delay in reporting; and
            (iv) The date by which you propose to report, or if you have already met the reporting requirement at the time of the notification, the date you reported.
      (5) In any circumstance, the report must be submitted electronically as soon as possible after the outage is resolved.
 Extensions for Force Majeure Events. If you are required to electronically submit a report through CEDRI, you may assert a claim of force majeure for failure to timely comply with that reporting requirement. To assert a claim of force majeure, you must meet the requirements outlined in paragraphs (d)(1) through (4) of this section.
      (1) You may submit a claim if a force majeure event is about to occur, occurs, or has occurred or there are lingering effects from such an event within the period beginning five business days prior to the date the submission is due. For the purposes of this section, a force majeure event is defined as an event that will be or has been caused by circumstances beyond the control of the affected facility, its contractors, or any entity controlled by the affected facility that prevents you from complying with the requirement to submit a report electronically by the due date. Examples of such events are acts of nature (e.g., hurricanes, earthquakes, or floods), acts of war or terrorism, or equipment failure or safety hazard beyond the control of the affected facility (e.g., large scale power outage).
      (2) You must submit notification to the Administrator in writing as soon as possible following the date you first knew, or through due diligence should have known, that the event may cause or has caused a delay in reporting.
      (3) You must provide to the Administrator:
            (i) A written description of the force majeure event;
            (ii) A rationale for attributing the delay in reporting beyond the regulatory deadline to the force majeure event;
            (iii) A description of measures taken or to be taken to minimize the delay in reporting; and
            (iv) The date by which you propose to report, or if you have already met the reporting requirement at the time of the notification, the date you reported.
      (4) In any circumstance, the reporting must occur as soon as possible after the force majeure event occurs.
      (5) The decision to accept the claim of force majeure and allow an extension to the reporting deadline is solely within the discretion of the Administrator.
 Recordkeeping. Any records required to be maintained by this subpart that are submitted electronically via EPA's CEDRI may be maintained in electronic format. This ability to maintain electronic copies does not affect the requirement for facilities to make records, data, and reports available upon request to a state or the EPA as part of an on-site compliance evaluation. For a minimum of 5 years after a performance test or performance evaluation is conducted, an owner/operator must retain and make available upon request, for inspection by the Administrator, the records or results of such performance test or performance evaluation and other data needed to determine emissions from a source.
Additional Specifications for Emission Reports
§51.40  In what form and format should emissions data be reported to EPA?
 General. A state or owner/operator reporting annually or triennially under this subpart must report the required data elements described in this section using the formats required by the EPA electronic data collection approaches described in §51.45 of this subpart. A state or owner/operator must use reporting code values for certain data elements consistent with §51.5(j) of this subpart. Because electronic reporting technology changes over time, the EPA provides the latest reporting format information and reporting codes on the EPA websites referenced in §51.5 of this subpart.
 Point sources.
 A state or owner/operator (unless the facility is eligible for and elects to comply with reporting as provided in §51.40(b)(3)) must:
 Report facility inventory data for the data elements listed in the "point" column in Table 2A to Appendix A of this subpart;
 Report emissions data for the data elements listed in the "point, airports, railyards" column in Table 2B to Appendix A of this subpart;
 Use the same unit, process, and release point identifiers for all pollutants emitted from the same unit, process, and release point at the facility; and
 Report daily activity data for small generating units described by §51.15(a)(3) and §51.27(b)(2) of this subpart using the data elements listed in Table 2C to Appendix A of this subpart.
 An owner/operator of a facility (or a state reporting on their behalf) is eligible to use the alternative reporting approach of §51.40(b)(3) for a facility when:
 The owner/operator is a small entity (as defined by §51.50 of this subpart);
 The owner/operator of the facility has never been notified that the EPA has modeled a cancer risk for that facility of 20/million or more, or the EPA has made such a notification less than 180 days prior to the next point source emissions reporting deadline as per §51.20 for owners/operators reporting to a state and as per §51.30 for owners/operators reporting to EPA; and
 Estimates of more detailed emissions are not required by a state.
 An owner/operator of a facility (or a state reporting on their behalf) meeting the conditions of §51.40(b)(2) may, as an alternative to the reporting requirements of §51.40(b)(1) report as follows:
 Report facility inventory data for the data elements required as per the "point (small entity)" column in Table 2A to Appendix A of this subpart; and
 Report emissions data for the data elements required as per the "point (small entity)" column in Table 2B to Appendix A of this subpart.
 Airports and rail yards. The EPA provides default data tables (e.g., a spreadsheet) for a state to use (as described by §51.5(k) of this subpart.
 To meet the requirement of §51.15(b)(1) or (2) and §51.15(c)(1) or (2) of this subpart, a state must use the data tables provided by the EPA to submit data in an electronic format.
 For a state that optionally reports emissions and documentation for these sources, the state must:
 Report facility inventory data elements using the data elements as described by Table 2A to Appendix A of this subpart.
 Report aircraft and rail yard source emissions using the data elements as described by Table 2B to Appendix A of this subpart.
 Nonpoint sources. The EPA provides default data tables (e.g., tools or spreadsheet) for a state to use for some nonpoint sources as described by §51.5(k) of this subpart.
 For nonpoint sources with EPA tools/spreadsheets excluding commercial marine vessels and locomotives (as described by §51.15(d)(3), a state must use (i.e., review and/or edit and submit online) the data tables provided.
 For a state that reports nonpoint actual emissions and documentation voluntarily or to meet a requirement of §51.15(d), the state must report nonpoint sources using the data elements listed in Table 2B in Appendix A of this subpart. Documentation must be submitted in one of the formats supported by the electronic reporting system described by §51.5(g).
 Onroad and nonroad sources.
 For a state submitting MOVES inputs, the state must use MOVES input formats for the version of MOVES and meet other requirements for electronic submission for a given inventory year (as described by §51.5(l).
 When California reports emissions to comply with §51.15(e)(3), the state must report data and documentation to comply using the data elements listed in Table 2B in Appendix A of this subpart. Documentation must be submitted in one of the formats supported by the electronic reporting approach (as described by §51.5(g)).
 Prescribed burning, wildfires, and agricultural. When reporting required and/or optional data for fires, a state must report data using the data elements listed in Table 3 in Appendix A of this subpart. The same format is used for both the mandatory data (prescribed burning except for agricultural burning or land clearance burning) and the voluntary data (wildfires and agricultural burning).
§51.45  How should states and owners/operators report the data required by this subpart?
 A state must submit required annual actual emissions and related data and documentation to comply with §51.15 of this subpart to the EPA through the EIS or a comparable electronic reporting approach provided by the EPA (as described by §51.5(g) of this subpart).
 An owner/operator must submit annual actual emissions and related data and documentation to comply with §51.25(a) or §51.27(b) of this subpart to the EPA through CAERS or a comparable electronic reporting approach provided by the EPA (as described by §51.5(h) of this subpart).
 An owner/operator must submit source test and performance evaluation data and documentation to comply with §51.25(b) of this subpart to the EPA through CEDRI or a comparable electronic reporting approach provided by the EPA (as described by §51.5(i) of this subpart).
§51.50  What definitions apply to this subpart?
Aircraft engine type means a code defining a unique combination of aircraft and engine used as an input parameter for calculating emissions from aircraft.
Activity data means data needed to calculate emissions using an emission factor or emissions calculation tool. Activity data varies depending on the emissions calculation approach and therefore the emissions source. Examples of activity data include fuel consumed for combustion emissions, landing and takeoff data for airport emissions, acres burned, material used for solvent evaporation emissions, and vehicle miles traveled for onroad mobile source emissions.
Actual emissions means, for the purposes of this subpart, the emissions of a pollutant from a source that is required to be reported under this rule, determined by accounting for actual emission rates associated with normal source operation and actual or representative production rates (i.e., capacity utilization and hours of operation). Actual emissions include emissions of a pollutant that occur during periods of startup, shutdown, and may include malfunctions. Since malfunctions are, by nature, unpredictable and given the myriad different types of malfunctions that can occur, malfunction emissions are difficult to estimate. However, to the extent that malfunctions become a regular and predictable event, then such emissions should be quantified with regular and predictable emissions and included in actual emissions.
Agency regulation description means the description of the state, local, or tribal regulation when reporting a regulation for which no code is available for reporting in EIS.
Agricultural burn means the use of a prescribed fire to burn crop residue.
Annual emissions means actual emissions for a facility, point, or process that are measured or calculated to represent a calendar year.
Air pollutants means criteria pollutants and their precursors, and hazardous air pollutants.
Aircraft engine type code means a code that defines the engine aircraft type for reporting airport emissions to EIS.
Broadcast burn means a prescribed burning event for which the biomass is burned in place, as opposed to being collected for a pile burn. Broadcast burning can include cuttings from fuels reduction treatments and logging slash that are not piled.
Combined Air Emissions Reporting System (CAERS) means the electronic reporting interface developed by the EPA to enable facility reporting to multiple EPA and state emissions reporting programs.
CDX means EPA's central data exchange, a system used for many electronic environmental data submissions to the U.S. EPA.
CEDRI means Compliance and Emissions Data Reporting Interface, a data collection system used by the EPA to collect electronic performance test reports, notification reports, and periodic reports.
CEMS means continuous emissions monitoring system, which is the total equipment necessary for the determination of a concentration or emission rate emitted from a source.
Control identifier means a unique code for a facility that identifies a control device, process specialization, or operational practice used to reduce emissions (e.g., wet scrubber, low NOX burner, flaring, process change, ban).
Control measure code means an EIS code used to specify the type of control measure.
Control measure percent pollutant reduction efficiency means the percent reduction achieved for the pollutant when the control measure is operating as designed.
Control percent effectiveness means an estimate of the portion of the reporting period's activity for which the control device was operating as designed (regardless of whether the control device is due to rule or voluntary).
Control pollutant code means the pollutant code for the pollutant associated with a control measure that has emissions changes caused by the control measure.
Control status code means the EIS code that identifies the operating status of the facility site (e.g., operating, temporarily shut down, permanently shut down).
Control status year means the first inventory year for which the reported control status code applies.
Emission calculation method means the code describing how the emissions for a pollutant were calculated, e.g., by stack test, continuous emissions monitor, EPA emission factor, etc.
Emission factor means the ratio relating emissions of a specific pollutant to an activity throughput level.
Emission operating type means the operational status of an emissions unit for the time period for which emissions are being reported, i.e., Routine (including Startup/Shutdown), Malfunction.
Emission process identifier means a unique code for the process generating the emissions.
Emissions year means the calendar year for which the emissions estimates are reported.
ERT means the Electronic Reporting Tool.
Facility air centroid coordinates means a latitude-longitude using the WGS84 or NAD83 datum that maps to or near the centroid of the air emissions activities at a facility.