Additionally, while owners/operators and states would be newly required to report for more facilities, states voluntarily reported HAP for the 2017 NEI (and therefore collected HAP from owners/operators largely via state requirements) for about 59,000 facilities, which is about 46% of the approximately 129,500 facilities EPA estimates would report under this proposal rule. As a result, the incremental burden increase of EPA's HAP collection approach would be lower than if all facilities needed to be newly reported under the proposed AERR revisions. In the cases in which a state does not choose to report HAP on behalf of owners/operators under this proposal, the HAP reporting requirements for such facilities could change in two possible ways. First, the reporting requirements could shift from being a state requirement to an EPA requirement for owners/operators of facilities within states that use CAERS in some way or that eliminate their state reporting rule. Second, the reporting requirements could become duplicative for owners/operators within states that choose to not use CAERS in any way and retain their state reporting rule. For those pollutants owners/operators are already reporting to the state, there is little increase in burden. For those additional pollutants (if any) that would be required under this proposed rule, owners/operators will have an incremental burden for those additional pollutants but would not need to learn about emissions reports in general. Further, the expected increase in facilities and burden needs to be considered in light of the need by EPA, states, and the public for data that allows for better understanding and reducing public health risks to communities. While the current AERR voluntary HAP collection program gathers a lot of data, the voluntary data does not necessarily have those pollutants that EPA's analysis shows are most important at those facilities and does not include all the facilities that the analysis shows should be collected to inform risk assessments and other EPA analyses.
Based on these considerations, this action proposes to expand the definition of point sources at 40 CFR 51.50 to mean a stationary or portable facility that (1) is a major source under 40 CFR part 70 for any pollutant, or (2) has PTE or annual actual emissions of pollutants greater than or equal to the reporting thresholds in Table 1A to Appendix A of this subpart, or (3) has a primary NAICS code listed in Table 1C to Appendix A of this subpart and annual actual emissions of pollutants greater than or equal to the HAP reporting thresholds (presented in Table 1B to Appendix A of this subpart). Additionally, the EPA is proposing as part of this definition that, in assessing whether emissions levels exceed reporting thresholds, all provisions of this subpart related to emissions estimation approaches would apply, including §§51.5 and 51.10 of this subpart.
To further clarify the definition of point sources based in part on primary NAICS (situation #3 in the paragraph above), the EPA additionally proposes a definition of primary NAICS. The EPA proposes that primary NAICS means the NAICS code that most accurately describes the facility or supplier's primary product/activity/service and that the "primary product/activity/service" is the principal source of revenue for the facility or supplier. This definition is being proposed so that the AERR can be consistent with the non-regulatory definition of primary NAICS used by the U.S. Census bureau. This proposed definition would serve for purposes of this subpart for both identifying point sources and reporting primary NAICS.
To set the point source definition, the EPA is proposing to expand the current Table 1 to Appendix A of Subpart A of Part 51 into four tables (Tables 1A through 1D of Subpart A of Part 51). Table 1A provides the proposed point source reporting thresholds for CAPs, which the EPA proposes would remain unchanged. Table 1B provides the proposed HAP initial reporting thresholds for non-major sources. Table 1C provides a proposed list of primary NAICS for non-major sources, and Table 1D provides a proposed list of individual compounds to be reported for groups of chemicals with a single reporting threshold from Table 1B. More information on Table 1D is provided in section IV.I.14 of this preamble.
9. Special Cases of Emissions Thresholds for Non-Major Sources
The risk-based analysis above was not completed for five situations, which are covered in this section: (1) mercury compounds, (2) pollutants included in the 2017 NEI but without URE or RfC , (3) revisions or publication of new URE or RfC, (4) a special case for dioxins/furans, and (5) the treatment of Pb as both a CAP and HAP.
The risk-based approach was insufficient for mercury compounds because they have multi-pathway (air, water, soil) effects that were not captured by the analysis described above. Without further evaluation to consider a more inclusive approach, the above approach may set too high a reporting threshold for mercury. It is important to ensure complete mercury reporting from sources because, in addition to using mercury data for risk analysis, the EPA reports trends in total national mercury emissions based on international agreements such as the Minamata Convention on Mercury and the Convention on Long-Range Transboundary Air Pollution. Evaluation of the available 2017 NEI data shows that the reporting threshold resulting from the mercury HI in the approach from section IV.A.8 of this preamble (0.15-ton) would require reporting for only 22 out of about 16,000 sources of mercury currently compiled in the 2017 NEI. Based on the 2017 emissions data to capture 95 percent of the mass of mercury nationally, a reporting threshold of 0.0026 tons (5.2 lbs) would be needed. To capture 99 percent of those known values, a reporting threshold of 0.0003 tons (0.6 lbs) would be needed.
The EPA also is considering that mercury emissions in its divalent form is the portion of mercury emissions of most concern. Unfortunately, sources often have little information about the form of the mercury emitted. Measuring divalent mercury is much more difficult than simply measuring the total mercury emitted.
Based on these considerations, the EPA is proposing a mercury reporting threshold of 0.0026 tons (5.2 lbs), which is based on the value that captures 95 percent of currently best available data about mercury from point sources. Irrespective of the form(s) of mercury reported, the reporting threshold is proposed to be based on total mercury. The proposed reporting threshold is about two orders of magnitude lower than the incomplete HI-based approach described above, which the EPA proposes is reasonable given what is known about multi-pathway exposures for mercury. The EPA additionally proposes that mercury would be reported in its more specific forms when such data are available, but that total mercury would be reported when more specific forms are not available.

 The EPA considered how to set a default emissions reporting threshold for all remaining pollutants without an URE or RfC. Without risk data to use to inform such an approach, EPA has proposed to use the major source threshold of 10 tons/year for a single pollutant. For the third special case, the EPA is considering that it may be useful to have a mechanism by which the Agency would revise reporting thresholds for pollutants in the case that a significant revision to an existing URE or RfC becomes available following new scientific findings that could significantly impact EPA's understanding of risk posed by such a pollutant. One example of this situation is provided by ethylene oxide (EtO), when the EPA determined EtO was a much more potent carcinogen than previously realized. Rather than being able to rely on an existing requirement to collect data more quickly as is being proposed here, the EPA needed to collect data ad-hoc from 2019 through to 2022 to obtain additional emissions data about these facilities. The data collection process took additional time, delaying a response that could have more quickly addressed public health concerns. This delay would have been avoided if emissions data reporting requirements had, at that time, included a provision such as the one the EPA is now considering.
The EPA has a tiered, prioritized list of appropriate chronic health benchmark values and, in general, the list prioritization places greater weight on the EPA-derived health benchmarks than those from other agencies. The EPA has a prioritization process aimed at incorporating the best available science with respect to dose-response information for air toxics. This information is obtained from various sources and prioritized according to (1) conceptual consistency with EPA risk assessment guidelines and (2) level of peer review received. Where the EPA lacks dose-response information with higher priority (e.g., IRIS), the Agency uses other information sources, such as from the Agency for Toxic Substances and Disease Registry (ATSDR) and the California EPA. To ensure the EPA could collect emissions data for HAP that receive updated health benchmarks that meet the EPA criteria and would receive prioritization, it would be necessary to adjust the health-based emissions reporting thresholds included in this proposal.
The EPA occasionally identifies new health benchmarks for pollutants that do not have them or revises the available benchmarks to reflect a new understanding of a HAP's increased or decreased toxicity. When the available toxicity information about pollutants changes in the future, the EPA expects that it will propose updated emissions reporting thresholds, take comment, and potentially issue final revisions to the HAP emissions reporting thresholds of this subpart. At this time, EPA plans to conduct such revisions in the future via very targeted rulemaking to amend just those HAP emissions reporting thresholds where the toxicity information has changed.
To streamline future actions associated with any revised health benchmarks, the EPA proposes that it may use the following formulas to develop updates for the point source HAP reporting thresholds of this subpart. For changes to UREs, the updated reporting threshold would be calculated using the formula: Updated reporting threshold = (reporting threshold in AERR x URE in 2022) / updated URE, where the "reporting threshold in AERR" refers to the reporting thresholds provided in the proposed Table 1B to Appendix A of this subpart. For changes to RfCs, the updated reporting threshold would be calculated using the formula: Updated reporting threshold = (reporting threshold in AERR x revised RfC)/ RfC in 2022.
Further, the EPA proposes that only those HAP reporting thresholds that the EPA publishes in the Federal Register (after notice and comment) 6 months before the end of an inventory year would apply for reporting emissions for that inventory year. For example, any reporting threshold published before July 1, 2027 would be relevant for emissions reporting of 2027 emissions, with those reports being due in 2028. This timing may not leave sufficient time for states to revise their HAP reporting regulations if they are reporting on behalf of owners/operators. Thus, the EPA recommends that states should consider the possibility of drafting their HAP reporting requirements such that they would refer to Table 1B to Appendix A of this subpart rather than list the same thresholds in their own rules. The EPA additionally proposes to publish any updates to emissions reporting thresholds on its Air Emissions Inventories website to help states and owners/operators to be able to find the new reporting thresholds more easily.
Some pollutant reporting thresholds included for non-major sources in the proposed Table 1B to Appendix A of this subpart are listed as 10 tpy, which is the major source threshold. If a point source had emissions of 10 tons, then it would presumably be subject to these proposed reporting requirements based on its status as a HAP major source, which would eliminate the need for including such reporting thresholds in the table. However, to support the possibility that an emission reporting threshold could be updated based on changes to a pollutant's URE or RfC, the 10-ton reporting threshold would be retained in the proposed Table 1B to Appendix A of this subpart to provide the "reporting threshold in AERR" value needed for the updated reporting threshold calculations proposed above. Additionally, including those pollutants in Tables 1B and 1D allows for a more comprehensive list of pollutants to inform owners/operators and states of EPA's expectations and so that the pollutant group relationships listed in Table 1D can be provided.
The fourth special case is dioxins/furans. These pollutants were not included in the risk-based approach described above since they were not included in the 2017 NEI and were not a part of the risk modeling work on which the approach relied. Given the extremely high toxicity of some dioxins/furan pollutants (called congeners), the EPA is considering the approach taken by the TRI program. In addition, while dioxins/furans are not listed as a group on the published list of HAP, these HAP are often treated as a group for various purposes. For example, the TRI program sets a reporting threshold for these compounds in the aggregate of 0.1 gram manufactured, processed, or otherwise used. For TRI reporting, when owners/operators report dioxins/furans, they must submit the mass of each of the congeners of dioxins/furans.

The EPA proposes the non-major reporting threshold for reporting dioxins/furans would be based on the TRI reporting threshold of 1.1 E-07 tons (~0.1 gram) and would apply to the sum of dioxins/furans mass. To meet this requirement, owners/operators would need to sum the mass of the individual congeners. By proposing this threshold for the AERR, the EPA is aligning the thresholds as best as possible to reduce complexity and burden. The EPA's proposed approach for the AERR is a less stringent threshold than the TRI threshold because facilities that manufacture, process, or otherwise use dioxins/furans would likely not emit all of that material to the air. As such, the EPA is not adding any burden on facilities to recognize that they may need to report to the AERR, but rather to estimate their dioxin/furan emissions at the additional level of detail proposed in the AERR as compared to the facility total emissions reported to TRI.
Finally, with respect to the Pb reporting threshold, the EPA is considering that Pb has a role for both CAP reporting and HAP reporting, since it falls under both NAAQS and air toxics provisions of the CAA. The EPA is not proposing to change CAP reporting thresholds (including Pb) in Table 1A to Appendix A of this subpart and is not proposing to change the current AERR requirement to report all CAP emissions if any CAP is above the PTE reporting thresholds (or Pb actual emissions threshold). The EPA approach for risk-based reporting thresholds described in section IV.A.8 results in a 0.074 tpy Pb reporting threshold. The EPA is considering that if it were to modify the CAP reporting threshold for Pb to be 0.074 tpy, this would have the effect of requiring reporting for all CAPs at facilities with Pb exceeding the 0.074 tpy threshold. The EPA does not intend to require CAP emissions (other than Pb) as point source for such small emissions levels. Based on these considerations, the EPA is proposing to retain the 0.5 tpy actual emissions reporting threshold for CAP reporting and additionally propose a Pb reporting threshold of 0.074 tpy actual emissions for purposes of HAP reporting.
Under the proposed approach, all states would continue to report Pb for point sources as required based on the CAP reporting thresholds. States that optionally report HAP on behalf of owners/operators would also report Pb for sources based on the HAP reporting threshold, and any other HAP from those facilities that would be required by this proposed action, and any other pollutants, including CAPs, that the state chooses to report. In states that do not report HAP on behalf of facilities, owners/operators would themselves be responsible for reporting Pb directly to the EPA for any facility that emits over the HAP reporting threshold (0.074 tpy) and that does not exceed the CAP reporting thresholds (for any CAP) and thus would not be required to be reported by a state.
Under the current AERR, some states voluntarily report Pb emissions for sources below the required reporting thresholds for CAPs. Thus, under the proposed approach, it is possible that the EPA could receive Pb data from both a state and an owner/operator for the same facility. In this case, the EPA would need to select one of these data values to include in the NEI. If an owner/operator is required to report (and does report) Pb emissions data for a facility (i.e., the state is not approved to report on their behalf), but the state also voluntarily submits that data for the same facility, then the EPA will use the data from the owner/operator. The EPA would plan to note any difference between the emissions submitted by the state and the owner/operator in quality review materials provided to both parties.
10. Pollutants to be Required or Optional for Point Sources
The EPA is considering which pollutants would be reported by owners/operators of facilities once a facility has been determined to be a point source. This action does not propose changes to which CAPs would be reported. With the proposed revision to require HAP, the EPA is considering how to handle cases in which a facility is required to report HAP but does not exceed the reporting threshold for CAPs. The term "incidental CAPs" will be used hereafter to refer to CAP emissions that would be reported only because a facility is a point source due to its HAP emissions. This situation is exemplified by a facility that emits one ton of nickel per year (exceeding the proposed Ni reporting threshold of 0.0021 tpy) but does not exceed the 100 tpy potential-to-emit reporting threshold for PM2.5. An ideal policy should include a mechanism to prevent the discrepancy that would result when the facility reports the nickel emissions of one ton and zero PM2.5 emissions, since nickel is a part of PM2.5.
To address this issue, the EPA is proposing to require reporting of incidental CAPs by owners/operators that report HAP for point sources, and by states when a state has been approved to report HAP on behalf of owners/operators. To support this requirement, the EPA is additionally proposing the definition of incidental CAPs to mean "a criteria pollutant or precursor emitted from a facility that meets the point source reporting definition due to emissions of HAP but has emissions of criteria pollutants and precursors below reporting thresholds for those pollutants." To inform this proposed approach, the EPA is considering whether a voluntary approach or a requirement would work best and the nature of any requirement.
Under a voluntary approach, owners/operators or states would not be required to report incidental CAPs, but such emissions could be reported voluntarily. This would impose a lower burden but may create inconsistencies in the NEI data at the facility level when CAP data are not voluntarily reported (as described by the example provided above about a facility reporting nickel without reporting PM2.5). To address any such inconsistencies, the EPA could augment the NEI by summing any HAP reported without associated CAPs. For example, if a facility were to report 1 ton of nickel, 0.2 tons of cadmium, and 0.3 tons of antimony as their only PM HAP, then the EPA could sum these values to include 1.5 tons of PM2.5 in the NEI. While avoiding inconsistency, this approach would create partial data for PM2.5 that would appear to be complete, and thus could cause confusion that would be better to avoid by estimating or collecting total PM2.5.
The EPA also is considering the possibility of using the required throughput (activity) data reported by owners/operators for the HAP to estimate the CAP emissions on behalf of owners/operators. This approach slightly reduces burden as compared to the proposed approach of requiring incidental CAP, though it complicates the NEI process and adds annual emissions data to the NEI after owners/operators have already submitted. In the past, the EPA has found that if owners/operators or states do not submit complete emissions, they can be surprised by EPA's additions to their data prior to NEI publication. Further, there is no guarantee that all sources of the incidental CAP at a facility also have emissions of HAP, making any estimate by the EPA based on throughput data used to estimate HAP potentially incomplete. In EPA's experience, these disadvantages are better avoided.
A requirement to report incidental CAPs has the advantages of collecting additional CAP emissions data for a more detailed NEI and boosting consistency between emissions of HAP and their associated CAPs (like VOC and PM2.5). Such a requirement would also have the disadvantage of additional burden on owners/operators to estimate and report more pollutants.
In considering a requirement to report incidental CAPs, the EPA is considering two possibilities for implementation: (1) states could be required to report CAP emissions of such sources rather than owners/operators, consistent with the overall CAP reporting approach taken in the AERR or (2) owners/operators could be required to report CAPs directly to the EPA consistent with the HAP reporting requirement. To implement the first approach, all states would need to modify their state regulations to update the definition of which sources would report CAPs to include HAP reporting thresholds. Such a modification would be necessary under the first approach, regardless of whether the state intends to be responsible for reporting HAP emissions on behalf of owners/operators. This poses a significant disadvantage.
The EPA is proposing the second approach listed above for owners/operators to report incidental CAPs. This approach does not require states to modify their CAP reporting regulations and still allows states to report incidental CAPs if they report HAP emissions. Under the proposed approach, the state HAP submission application and approval process described in section IV.A.6 of this preamble would therefore also include the reporting by states of incidental CAPs associated with such facilities. The proposed approach also works well with the requirement for owners/operators to report emissions using CAERS, because CAERS assists owners/operators with emissions factors for both HAP and CAPs associated with their emissions processes and provides other advantages to streamline reporting. Additionally, the EPA plans that future versions of CAERS would have the direct access to the source tests reported to CEDRI to support use of source test data for estimation of incidental CAP. The EPA expects the source test data to be useful for this, because of the frequent approach taken by NESHAP rules to collect a surrogate pollutant report, such as filterable PM2.5, to ensure compliance with HAP emissions limits. Thus, the incremental burden for a facility reporting to the EPA directly via CAERS to report incidental CAPs would be lower than if CAERS were not required. Since some such facilities may not already be regulated for CAPs by states, some may be less likely to have source testing or other emissions factor data. In these cases, owners/operators could simply use the default emissions factors provided by the EPA in CAERS when available.
Based on these considerations, the EPA proposes that owners/operators would be required to report incidental CAPs associated with HAP being reported when they are required to report HAP but would not otherwise be required to report CAP (i.e., they are not a major source for CAP). This requirement would impact reporting emissions for HAP major sources and for non-major sources when required to report HAP.
If applying to the EPA to report HAP on behalf of owners/operators, a state would need to consider the incidental CAP requirement when designing any updated emissions collection regulations. The proposed Table 1B to Appendix A of this subpart includes which criteria pollutants are associated with each HAP and would determine the CAPs expected to comply with this propose incidental CAP reporting requirement. This approach has the advantages previously noted and, in addition, it solves the same collection and consistency challenge for states by providing a framework for any states that choose to report HAP on behalf of owners/operators.
In addition to incidental CAPs, the EPA is considering which HAP would be reported by owners/operators of facilities that meet the point source definition. As described above, this action proposes that owners/operators of HAP and CAP major sources report all HAP. This proposed requirement would be consistent with EPA's obligations under the Act to regulate all pollutants from such HAP major sources and includes CAP major sources to have available to the agency a complete suite of pollutants from all large emitters.
For non-major sources, the EPA proposes that owners/operators would be required to report only those HAP that are greater than EPA's HAP reporting thresholds, initial values for which are presented in the proposed Table 1B to Appendix A of this subpart. To identify this proposed approach for non-major sources, the EPA compared this proposed approach to an alternative by which owners/operators of non-major sources would report all HAP when any one HAP has emissions greater than or equal to the proposed reporting thresholds. To choose an approach, the EPA is weighing the additional burden associated with reporting all HAP relative to the importance of additional data that would be collected if all HAP were required.
To understand the effects of this proposed action, the EPA evaluated the relative impact of the HAP pollutant requirements. The incidental CAP impact is expected to be small because it would add just one or two pollutants per facility and the requirement could be met using emissions factors. Thus, the incremental CAP impact was not separately analyzed from the total HAP impact. The EPA used the 2017 NEI data to estimate the number of additional combinations of facilities and HAP pollutants as a surrogate to estimate incremental burden from each policy choice relative to the option of reporting all HAP for HAP major sources. Table 1 below provides these results by including a "burden" factor calculated using the estimated number of facility-pollutant combinations associated with a policy option divided by the estimated number of facility-pollutant combinations associated with all pollutants from the identified HAP major facilities.
These relative burden estimates are imperfect because they rely on the 2017 NEI that is known to be incomplete (since HAP reporting is currently voluntary), but they still represent the best data available to the EPA at the time the analysis was performed. To compare the burden between the proposed non-major approach and the alternative non-major approach, the EPA counted the number of records in the 2017 NEI with HAP emissions. In the proposed case, the EPA included only those records associated with the HAP at a facility for HAP exceeding the proposed thresholds. For the alternative case, the EPA included all HAP records at a facility when any HAP exceeded the proposed thresholds. Based on these counts, the EPA estimates a 40% increase in burden associated with the alterative that the EPA is not proposing.
The EPA has considered whether a 40% burden increase to collect additional HAP data (below risk-based reporting thresholds) from non-major sources would be warranted. In considering this, the EPA has been unable to identify a reason to collect those additional HAP (unlike for major sources, which as noted starting in Section IV.A.4 of this preamble, the Act directs EPA to consider all HAP). While the data would certainly be more complete under the alternative approach, the risk-based reporting thresholds that the EPA is proposing would provide substantially more data than the Agency currently has. Rather than impose additional burden, the EPA is proposing to require that owners/operators of non-major sources would report emissions only when those emissions are greater than or equal to the HAP reporting thresholds, presented in Table 1B to Appendix A of this subpart, but subject to revision as described above. The EPA urges commenters to provide comment to it regarding any factors the Agency may have missed in selecting the proposed approach.
In addition to the burden of the various policy options for HAP emissions reporting, the EPA evaluated the distribution of sources across communities for informational purposes. The results in Table 1 provide three types of areas where facilities emit pollutants in amounts that classify those sources as major sources or levels of HAP for non-major sources that meet the proposed reporting thresholds of this action. Table 1 illustrates the demographic make-up of the populations located within 5 km of the facilities that would be required to report under the proposed policy options. The demographics are based on indicators from the Bureau of Census' 5-year American Community Survey (ACS). The column "Nationwide" represents the nationwide average percent demographics for comparison. The following three columns "CAP Major", "HAP Major", and "Non-Major", represent the average percent demographics of the populations living within 5 km of the facilities in each group of facilities. For this analysis, the EPA used a 5-km distance to try to capture the appropriate demographics for near-field exposures. Based on previous air dispersion modeling of HAP emissions from over 1,600 facilities in 22 source categories, the average distance of the maximum individual cancer risk (MIR) is about 2 km from the facility. A distance of 5 km was chosen because it captures 95 percent of MIR locations for these 1,600 facilities. Section 6 of the TSD provides additional details. Regarding race and ethnicity, the data show that on average, the populations living around facilities affected by this action are above the percent national average. While the national average population for African Americans is 12 percent, the percentage of this demographic group near facilities is between 15 and 17 percent, depending on the facility type. Similarly, the Hispanic/Latino population average is 19 percent, and the percentage of this demographic near facilities is 22 to 23 percent. For the Other Multiracial population, the average nationally is 8 percent while the percentage of this demographic near facilities is 9 to 10 percent. In addition, the populations living around facilities affected by this action are above the percent national average for "Below Poverty Level", "Over 25 and without a High School Diploma", and "Linguistically Isolated." Since the reporting thresholds are largely based on risk contribution, these results show that owners/operators will report HAP from facilities emitting at levels contributing to risk in both low-income areas an in communities with a higher minority population than average.
Table 1: Percent of Population by Demographic for Populations Nationwide and within 5km of CAP Major Facilities, HAP Major Facilities, and Non-Major Facilities
                               Demographic Group
                                  Nationwide
                                  CAP Major:
                  Population within 5 km of 4,067 Facilities
                                  HAP Major:
     Population within
5 km of 7,552 Facilities (including HAP/CAP Major)
             Non-Major: Population within 5 km of 6,096 Facilities
Total Population[a]
                                  328,016,242
                                  69,683,592
                                  117,946,858
                                  93,000,649

                        Race and Ethnicity by Percent
White
                                      60%
                                      50%
                                      52%
                                      52%
African American
                                      12%
                                     17%
                                      16%
                                      15%
Native American
                                     0.7%
                                     0.4%
                                     0.4%
                                     0.4%
Hispanic or Latino (includes white and nonwhite)[b]
                                      19%
                                      23%
                                      22%
                                      23%
Other and Multiracial
                                      8%
                                      9%
                                      9%
                                      10%

                               Income by Percent
Below Poverty Level
                                      13%
                                      16%
                                      16%
                                      15%
Above Poverty Level
                                      87%
                                      84%
                                      84%
                                      85%

                             Education by Percent
Over 25 and without a High School Diploma
                                      12%
                                      14%
                                      14%
                                      14%
Over 25 and with a High School Diploma
                                      88%
                                      86%
                                      86%
                                      86%

                      Linguistically Isolated by Percent
Linguistically Isolated
                                      5%
                                      8%
                                      7%
                                      7%
[a] 	The nationwide population and all demographic percentages are based on the Census' 2015-2019 American Community Survey five-year block group averages and include Puerto Rico. The total population count within 5 km of all facilities is based on the 2010 Decennial Census block populations.
[b] 	To avoid double counting, the "Hispanic or Latino" category is treated as a distinct demographic category for these analyses. A person who identifies as Hispanic or Latino is counted as Hispanic/Latino for this analysis, regardless of what race this person may have also identified as in the Census.
Table 2 below provides the estimated number of known facilities from the 2017 NEI expected to be impacted by these proposed HAP reporting requirements for which the average percent of the population within 5 km exceeds the national average for different demographics. These results show that a significant number of the known facilities for which the proposed action could collect better data are located near areas of interest for environmental justice issues.
Table 2: Number of Facilities for which the Population within 5 km Exceeds the National Average for Different Facility Categories and Different Demographics.
                             Demographic Group[a]
                             CAP Major Facilities
                 HAP Major Facilities (includes HAP/CAP Major)
                             Non-Major Facilities
                          Total Number of Facilities
                                     4,067
                                     7,552
                                     6,096

                              Race and Ethnicity
White
                                     2,393
                                     4,878
                                     4,306
African American
                                      958
                                     2,608
                                     1,231
Native American
                                      731
                                     1,287
                                     1,664
Hispanic or Latino (includes white and nonwhite)[b]
                                      974
                                     1,657
                                     1,396
Other and Multiracial
                                      679
                                     1,088
                                     1,014

                                    Income
Below Poverty Level
                                     1,812
                                     4,082
                                     2,649

                                  Education
Over 25 and without a High School Diploma
                                     1,793
                                     3,959
                                     2,606

                           Linguistically Isolated
Linguistically Isolated
                                      811
                                     1,338
                                     1,012
[a] 	Demographic data are based on the Census' 2015-2019 American Community Survey five-year block group averages and include Puerto Rico. The total population count within 5 km of all facilities is based on the 2010 Decennial Census block populations.
[b] 	To avoid double counting, the "Hispanic or Latino" category is treated as a distinct demographic category for these analyses. A person who identifies as Hispanic or Latino is counted as Hispanic/Latino for this analysis, regardless of what race this person may have also identified as in the Census.

11. Reporting Release Coordinates
In conjunction with the proposed requirements to report HAP emissions, the EPA is considering the need for accurate location information of HAP emissions releases to be able to perform appropriately detailed assessments of risk using models. The EPA estimates concentrations and associated risk from HAP emitted from facilities using the AERMOD modeling system and uses HAP emissions in other models for various analyses. These models rely on emissions data as input, and the most complete modeling approaches include emissions at the many individual release points that can exist at facilities. Large facilities can have hundreds of individual release locations, and the proximity of those releases to people and communities is an important aspect of proper risk estimation for populations. Emission releases are compiled in the NEI as either stack releases or fugitive releases.
The EPA proposes a requirement that owners/operators and states reporting emissions data directly to the EPA would report release point locations that are distinct from the facility location. This proposed requirement would apply for both stack locations and fugitive release locations. To arrive at this proposed approach, the EPA is considering a variety of factors described in this section.
Stack and fugitive releases in the NEI are already required to be reported by the current AERR. In addition, stack parameters such as height, release diameter, exit gas temperature, and exit gas velocity are also required so that models can simulate the buoyancy of emissions plumes and dispersion in surrounding areas. For fugitive releases, the current AERR also requires parameters to characterize the shape of the fugitive release as 2- or 3-dimensional, the width, length, and height of the emissions release, and the orientation of the release shape. In both cases, however, the current AERR does not require that release point locations be specific to each release point. Rather, it allows states to report only the overall facility location, and, in that case, the EPA uses the facility location to set default release point locations for that facility when states do not provide specific release point locations.
The current AERR approach was promulgated in 2015 (80 FR 8787, February 19, 2015). In that final rulemaking, the EPA changed the requirement for states to provide X Stack Coordinate (longitude) and Y Stack Coordinate (latitude) only at the facility location, rather than for the stack locations. In that final action, the EPA explained that "most states do not have accurate location values for each individual release point within a facility; instead, they frequently report the same locations for all stacks within a facility" (80 FR 8792, February 19, 2015). In addition, the EPA stated that "the vast majority of facilities are geographically small enough that such a simplification does not reduce the usefulness of the data and we encourage states to optionally report individual stack locations to add accuracy beyond the single facility center location. The EPA may also add such individual stack locations where the agency believes it has accurate data" (80 FR 8792).
The context of that AERR revision was within the requirements for collecting CAP emissions. The primary use of the NEI for CAP pollutants is for Eulerian grid modeling such as the Community Multiscale Air Quality (CMAQ) modeling system, for which emissions sources are mapped to grid cells for modeling. These grid cells are typically 4- or 12-km, which is the context for the statement made in the 2015 AERR revision that "the vast majority of facilities are geographically small enough that such a simplification does not reduce the usefulness of the data" (80 FR 8792). For the case of such grid modeling, using a single facility-wide latitude/longitude for stacks would at worst, misplace some of the emissions from a facility into a neighboring grid cell when a facility size is such that it crosses a grid cell boundary. Given other modeling uncertainties of Eulerian grid modeling, this additional uncertainty would not be a concern for most modeling applications in the relatively few cases where it occurred. In cases that need more locational detail, the EPA could revise the inventory to correct any release point locational inaccuracies caused by the current AERR's approach to the release point coordinate requirements. The EPA received no comments regarding this revision during the comment period for the June 20, 2013 proposed rule (78 FR 37164).
In the context of the HAP emissions reporting requirements proposed in this action, the EPA is revisiting the requirement for accurate release point locations. The EPA's experience with risk modeling using HAP emissions inventories has been that using default facility locations for all release points provides lower quality results than when models use more detailed data. Using imprecise locations can provide inaccurate risk information that could overstate or understate cancer risk significantly. Research has concluded that improved locational data and release parameters can reduce uncertainty in a risk assessment by up to 2 orders of magnitude. These modeling results are especially sensitive to the distance between the residential receptor and the emission sources, especially for facilities that have a large industrial footprint.
Because risk is very related to proximity of the source to populations, when a large facility has emissions releases that border neighborhoods, the risk can be greatly understated if EPA were to use a single central facility-wide location. The EPA's modeling guidance for urban air toxics modeling explains that "each source will need to be classified as a point, area, volume, or line source," and that "building the source inventory usually begins with mapping the locations of emissions sources." Also in the guidance, subsections in Section 1.3 indicate how modelers should define each of the different types of release points and specify "location of the source" (point source characterization), "location, geometry, and relative height" (for 2-dimensional release points, called "area sources" in the guidance).  Likewise, Section 7.2 of the "Air Toxics Assessment Reference Library, Volume 2, Facility-Specific Assessment" explains that model inputs needed by the Human Exposure Model (HEM) require "the geographical location (latitude and longitude) of each source being simulated (with "source" in this context being each release point at a facility) and states that "the model requires that coordinate data be obtained for each emission source in the analysis, and that each emission source is modeled individually."
As further evidence of this need, EPA has previously found it necessary to collect limited sets of this data from certain industries to support modeled risk analysis for the Risk and Technology Review (RTR) program required by CAA Sections 112(f)(2) and 112(d)(6). These one-time requests included collection of release point location and other parameters for stack and fugitive releases. As explained above in Section IV.A.1, these one-time collections tend to impose sporadic and reoccurring "start-up" burden on owners/operators associated with expending time and resources on understanding and responding to the requests. While the mandatory risk reviews under CAA Section 112(f)(2) have been completed for most of the source categories listed under CAA section 112, the EPA may conduct future risk reviews that are discretionary under the CAA. Further, the EPA does have the continuing obligation to conduct a technology review under CAA 112(d)(6) for each HAP standard every 8 years. Under this proposal, data for these future reviews would already be available to the agency rather than needing to issue a continuous and never-ending stream of individual data collection requests. Having the data available will allow EPA to be timely in meeting these CAA obligations.

In the previous AERR revision, we identified one reason for the change of release point location data to be optional as the lack of available information from states. The collection approach proposed by this action would avoid this limitation because it would allow for owners/operators to directly report release point locations and parameters in support of the proposed requirement to collect and submit HAP emissions data. As defined by 40 CFR 2.301(a)(2)(i), emissions data includes those parameters necessary to characterize the emissions, which, in the context of HAP emissions, includes the release locations and parameters required in Table 2a to Appendix A of Subpart A of Part 51.
Another relevant consideration for release point locations is the ease with which such data can be obtained now. Global Positioning System (GPS) applications are readily available on ubiquitous cell phones for employees of both small and large companies to compile such information. For stack releases, coordinates for the center of a stack can be readily obtained either with a GPS approach or using readily available online mapping software to pinpoint the locations of stacks and fugitive releases.
Based on these considerations, the EPA proposes that any owners/operators reporting emissions data directly to the EPA (other than small entities as per IV.A.12) would be required to provide specific release point locations that are distinct from the facility location. Considering the complexity of facilities and that release points frequently emit both CAPs and HAP, the EPA proposes that this requirement be applied to all release points reported in the facility inventory (i.e., not only those release points that emit HAP). In addition, to keep the quality assurance of the incoming data manageable, this approach will allow the EPA to have detailed release parameter data for SO2 and PM2.5, which also can be modeled using AERMOD and fine-scale modeling tools as part of permitting and other NAAQS programs. To be consistent with requirements across the inventory collection process, the EPA additionally proposes that state programs would be required to report all release points using release point locations that are distinct from the facility location. These proposed requirements apply for both stack locations and fugitive release locations.
12. Reduced HAP Reporting Requirements for Small Entities
In developing this proposal, the EPA convened a Small Business Advocacy Review (SBAR) Panel in compliance with Section 609(b) of the Regulatory Flexibility Act (RFA) as amended by the Small Business Regulatory Enforcement Fairness Act of 1996 (SBREFA). In addition to EPA's Small Business Advocacy Chairperson, the SBAR Panel consisted of the Director of the Air Quality Assessment Division of OAQPS, the Administrator of the Office of Information and Regulatory Affairs (OIRA) within the OMB, and the Chief Counsel for Advocacy of the Small Business Administration (SBA). The SBAR Panel recommended many accommodations for small entities to reduce their burden while still allowing this proposal to collect data needed to meet EPA's objectives under the Clean Air Act. A copy of the full SBAR Panel Report is available in the rulemaking docket.
The SBAR Panel recommended, among other things, that the EPA propose allowing any small business subject to revised reporting requirements under this proposal to report aggregated emissions for the facility as a total fugitive emissions value rather than the detailed emissions by process and release point. Since the EPA is not proposing to change reporting thresholds for criteria pollutants, this recommendation only applies to HAP emissions reporting and any incidental CAP emissions (as described in section IV.A.10).
During the SBAR Panel, the EPA observed that risk modeling using facility total emissions would be more conservative than using more detailed emissions that could include stack releases, because all emissions would be modeled as ground-level fugitive emissions. With more specific data about emissions releases (e.g., through stacks raised above ground level), the modeling includes more dispersion of pollutants that can lower modeled concentrations at the ground level thereby lowering modeled risk. The EPA additionally observed that if modeled risk from facility total emissions were high enough, the Agency would have an interest in collecting more detailed data to better assess risk. While aggregated data (facility total emissions) are not as useful to the EPA as the more detailed data, this approach balances EPA's needs for these data with the burden on small businesses. Under this proposed approach, EPA's available data is less complete, although still helpful, and the burden on small businesses is reduced when compared to the requirement to report the full suite of detailed data that the EPA is proposing to require for other sources that are not small businesses.
In addition, because states are free to have emissions collections that include sub-facility detail irrespective of any final AERR provisions, states may collect more detailed data than would be required by the AERR. The EPA observes that EPA, states, and owners/operators have a shared interest in ensuring that the EPA has the more detailed data to support risk assessment and other work.
Based on these considerations, the EPA proposes to provide owners/operators the option to report a facility's total emissions instead of the detailed data otherwise required when (1) they meet the small entity definition as proposed by this action, (2) the owner/operator has never been notified that the EPA has modeled a cancer risk for the 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, and (3) estimates of emissions with the process-level detail that would otherwise be required by this proposed action are not required by a state.
The EPA is considering the facility total cancer risk level above which an owner/operator would not be able to use the optional facility-total reporting accommodation (item 2 in the previous paragraph). The cancer risk level range under consideration is from cancer risk of 1/million, which is the level used to develop the proposed emissions reporting thresholds for HAP to 100/million, which is a level the EPA uses to help formulate emissions reductions strategies as part of NESHAPs and other HAP regulatory programs. In addition, the EPA is considering the degree of uncertainty that can exist when estimating risks through modeling and is recommending that a modeled cancer risk between 10/million and 30/million would be appropriate to warrant more detailed emissions reporting. Using a cancer risk of 1/million for this purpose would not provide much burden reduction because 1/million is the basis of the proposed HAP reporting thresholds, above which non-major sources would need to report. Beyond a cancer risk of 30/million, the upper uncertainty range is more likely to reach 100/million, for which the EPA certainly needs better HAP data.
As previously noted, the EPA is proposing that if its modeling shows 20/million or more cancer risk, small businesses would need to report more detailed emissions. EPA is taking comment on a cancer risk range of 10/million to 30/million for this potential threshold. In this proposed cancer risk range for comment, the EPA is considering that this range represents a 10-fold to 30-fold accommodation for small businesses beyond achieving less than 1/million cancer risk as laid out for EPA in the CAA.  The target of cancer risks of 1/million or lower is included at CAA 112(c)(9)(B)(i), which describes that the EPA may delete a source category from the list of categories if, among other requirements, the EPA determines that no source in the category emits HAP in quantities which may cause a lifetime 1/million risk of cancer. Likewise, CAA 112(f)(2)(A) directs EPA to promulgate emissions standards that "shall provide an ample margin of safety to protect public health" and to promulgate standards beyond standards set by CAA 112(d) if those standards "do not reduce lifetime excess cancer risks ... to less than one in one million."
The EPA encourages commenters to provide feedback on the proposed choice of the midpoint of this range of 20/million estimated cancer risk to provide accommodations to small businesses. The EPA seeks to learn about any considerations that the EPA may have failed to consider in proposing this midpoint.
In addition to allowing for facility-wide reporting in certain situations to reduce burden on small entities, the EPA is considering how best to reduce burden for reporting the facility inventory. For owners/operators that are not small entities, the current AERR requires states to report the attributes for the facility (e.g., name, address) as well as component attributes for emissions units, release points, processes, and controls. These data elements are required under the current AERR, but states report the facility inventory separately from emissions because facility attributes do not vary every year. After the first report for a facility, states under the current AERR and states and owners/operators under these proposed revisions would need only to report modifications to the facility inventory after the first year. For example, if a facility adds or removes a unit, then those changes would be submitted but the other facility attributes could likely be retained without resubmission. In the case of facility-wide emissions reporting, the facility inventory would not necessarily need sub-facility data to support the emissions reports, since emissions would not need to be allocated to the units and processes within the facility.
In addition to the facility total emissions, the EPA needs to know which units are present at facilities and which units are subject to NESHAPs or other air emissions regulations. As described in section IV.I.8, the EPA is proposing that states and owners/operators of permitted sources would be required to provide the regulatory codes that apply to units and/or processes. To fulfill EPA's need for this information while reducing burden, the EPA is proposing that small entities would only need to report a list of their units, including all required unit-level data elements. This would reduce burden while still allowing the EPA to identify which units at each facility are subject to regulations.
The EPA provided an analysis for the SBAR Panel that estimated the number of small entities expected to report based on EPA's proposed HAP emissions reporting thresholds. This analysis showed that the collision repair industry characterized by NAICS 811121 (Automotive Body, Paint, and Interior Repair and Maintenance) is unique in that it has the most small entities of any industry that the EPA is considering including in the proposed rule according to the 2017 Economic Census data, and that much smaller number of the largest collision repair facilities (about 2,000) are estimated to fall within the emissions reporting thresholds under consideration. Given that the EPA is already receiving data through states from about 2,300 of such sources, the EPA is unlikely to reduce the number facilities for which emissions data must be reported below the number it is already receiving. The EPA reviewed other NAICS in this way, but no other NAICS presented a similar situation. In other industries, the EPA either estimates that many more sources would need to report based on these proposed requirements or the EPA lacks sufficient existing emissions data for facilities with those NAICS to perform the same analysis.
To balance the potential burden with the need for information and considering the large number of businesses in the collision repair industry, the SBAR Panel recommended that the EPA consider explicitly excluding small entities in the collision shop industry from new reporting requirements. Such an approach would still collect HAP data from many more facilities than are available to the EPA currently, while not burdening small entities. To address this panel recommendation, the EPA proposes to exclude small entities (except for major sources) with primary NAICS 811121 from any HAP reporting requirements under the AERR. This proposal reflects this accommodation in Table 1C of Appendix A of this subpart, which lists primary NAICS codes subject to non-major source HAP reporting requirements.
Another concern identified during the SBAR Panel was that small entities that are not already reporting emissions data to the EPA or a state may not have the necessary experience and resources to develop emissions estimation approaches where none are readily available. The SBAR Panel additionally noted that small entities would have the lowest burden when the EPA provides an emissions estimation method or there are already some other readily available emissions estimates to use because that business must report emissions to the state or TRI. The SBAR Panel Report also noted that small entities may have source test data with which emissions estimates could be made. The Panel recommended that, consistent with these concerns, a small entity would not be expected to report emissions for pollutants when the EPA does not provide a way to estimate emissions and there is no other readily available data for that pollutant.
The EPA is considering how best to address these SBAR Panel recommendations. For current AERR requirements regarding state reporting, the EPA does not address the availability of emissions estimation methods for facilities. The presumption of the current regulations is that states, in collecting data from facilities to report to EPA, would ensure that the requirements to report all CAP are met when any CAP exceeds the reporting threshold, irrespective of whether the EPA provides an emissions calculation method.
The EPA has observed in working with states under the current AERR that many states rely on the EPA WebFIRE database for emissions factors for use by owners/operators to calculate emissions in state collection systems. In the absence of source test data or site-specific emissions factors created by the facility, the collections would therefore use an EPA approach and when none is available, would be less likely to report the pollutant. Many states with HAP collection programs have also developed emissions factors, and state reports for many HAP include emissions based on these state factors. As a general matter for emissions reporting under the current AERR, when EPA, a state, or a trade association does not provide emissions calculation methods for a process/pollutant combination (even when emissions from such a combination is likely to exist), the EPA has observed that emissions data reported by states is much less likely to include emissions for that process/pollutant combination.
Based on this experience, the SBAR Panel recommendation is consistent with EPA's understanding of the practical reality of the data collection process for all businesses currently reporting to states. Namely, when EPA, states, or trade associations do not provide an emissions calculation method for a given process/pollutant combination and owners/operators do not have source tests or other readily available data, emissions reports do not include emissions for those process/pollutants. The EPA recognizes that this could be occurring irrespective of whether those processes/pollutants are required to be reported under the current AERR and state programs. As described in the next section, the EPA intends to provide an emissions estimation tool for small entities to use in support of implementing the proposed requirements. The emissions estimation tool would provide a way for small businesses to estimate their facility-wide emissions to assess whether their emissions exceed the non-major HAP emissions reporting thresholds. If they do exceed the thresholds and the owner/operator determines they must report, the emissions estimation tool would allow those estimates to be submitted to EPA (and states) via CAERS. The EPA expects that providing this tool will assist with reducing situations where required data are not reported. In this section, the EPA also addresses how development and use of this tool would lessen the burden on small entities if the provisions of this proposal were finalized.
13. Emissions Estimation Tool for Small Entities
The SBAR Panel recommended that the EPA develop an emissions estimation tool to help small entities estimate facility-wide emissions. The emissions estimation tool could be used by small entities to help them determine if their facility-wide emissions are above HAP reporting thresholds and to provide an emissions value for small entities to submit when emissions exceed the reporting thresholds. The SBAR Panel recommended that the EPA adopt emissions estimation approaches that rely on information that small entities can readily gather in the normal course of business.
To address these recommendations, the EPA plans to develop an emissions estimation tool to help small entities estimate facility-wide emissions. The EPA would develop this tool between the time this rule is proposed and the first year of any new point source reporting (see section IV.F for timing information). While CAP emissions may be included in this tool, the EPA would prioritize HAP emissions because other than the addition of incidental CAP to reporting requirements, the EPA is not considering changing CAP reporting thresholds with this proposal. The emissions estimation tool would include incidental CAPs as relevant, depending on the HAP. The greatest, and most urgent, need for assistance will be for those small entities that do not have to report for any pollutants under the current AERR.
With this tool in mind, the EPA is considering the SBAR panel recommendation described in section IV.A.12 that the EPA should not expect small entities to develop new emissions estimation approaches when none are available. The EPA agrees in principle with this recommendation but also wants to maintain a straightforward but flexible implementation of the proposed requirements. The EPA has proposed the criteria for point source reporting to include major source status, and for non-major sources, primary NAICS codes and emissions levels. The EPA believes that adding a regulatory exemption based on emissions estimates generated by a yet to be established and evolving tool would add unnecessary complexity to the structure of the rule. This is in part because states can choose to report HAP on behalf of owners/operators. Thus, if the planned tool were to provide a regulatory exemption, states could also be expected to rely on EPA's tool, limiting their autonomy for implementation of HAP reporting requirements. While additional considerations could be included in a proposed rule to avoid that limitation, the EPA expects that such additions would add complexity and confusion that the EPA is seeking to avoid. Further, such a regulatory exemption which relied on use of such a tool could increase the burden on small entities (i.e., could increase recordkeeping and reporting burden compared to the current proposal).
Further, given EPA's observations that common practice under the current AERR is for states and owners/operators to rely on EPA, state, or trade association emissions estimation approaches when better information is not available, a logical conclusion is that this situation would continue to occur under these proposed revisions to the AERR. The EPA would expect that in circumstances where better data were available for estimating emissions, the emissions estimation tool would not be used. Such an approach would be consistent with the planned AERR requirement to use the best available emission estimation methods (see section IV.I.6 of this preamble). Similarly, when emissions estimates are made by an owner/operator for TRI or to meet state requirements, those emissions would be appropriate for reporting emissions to the EPA under these proposed requirements. The EPA emissions estimation tool could be used when these other emissions estimation approaches are not available, including when a state is also relying on EPA's tool to support owners/operators reporting to them, so states can report to the EPA on their behalf.
When none of these other emission estimation approaches are available, and no emissions are estimated by the emissions estimation tool, the EPA would not expect owners/operators of small entities to develop their own emissions reporting approaches because the burden associated with doing so is not warranted. If the EPA is sufficiently concerned about an emissions source, then the EPA could develop an emissions estimation approach and include it in its emissions estimation tool to assist small entities. The EPA could do so using other data available from larger businesses including emissions reports and source test data (as described in section IV.C of this preamble), or if needed, issue a specialized data collection separate from this proposed rule.
The SBAR Panel had many additional recommendations about the development and outreach associated with an emissions estimation tool. It recommended that the EPA work with small entities and trade associations to develop emissions estimation tools that would properly reflect the emissions processes and pollutants associated with each industry. It also recommended that as the EPA incorporates new information into its emissions estimation tool, the EPA should provide that information for industry and other parties to review and provide feedback. In addition, the SBAR Panel recommended that the EPA should provide adequate time for such feedback and for revising the tool based on the feedback, dissemination, and training before requiring a new tool to be used for any given emissions reporting year. It further recommended that the EPA coordinate with Small Business Environmental Assistance Programs (SBEAPs) in each state to support the outreach and developing guidance for small entities. Finally, the SBAR panel recommended that the EPA provide a list of units and processes for which small entities could select for emissions reporting for review and feedback.
As previously described in section IV.A.12, the EPA is proposing to provide an optional accommodation for small entities to report emissions as a facility total under certain conditions and is proposing that the accommodation would not be available if EPA's risk modeling shows estimated cancer risk of 20/million or more. If a final rule were to exclude the proposed accommodation for facility-total emissions reporting, the SBAR panel recommended that the EPA make sure that, when requiring emissions to be provided for higher level of detail, emissions calculation methods are available for use by a small entity that reports for any such facility.
To address the development and outreach recommendations of the SBAR Panel, the EPA is considering an ongoing development and review approach for the emissions estimation tool. First, in developing the initial tool prior to any new reporting for small entities, the EPA would consult with the public including industry representatives and other interested parties. This initial development would begin sometime after receiving comments on this proposal and would end prior to the first deadline for point source reporting under any revised requirements. The EPA would include in the tool emissions factors from a variety of sources. For the initial release of the tool, the EPA plans to provide the tool and underlying data at least 12 months before the first reporting deadline, giving 3 months for feedback. The EPA would consider such feedback and incorporate changes in the tool before releasing the initial version of tool in advance of any new reporting deadlines for small entities.
The EPA expects that development of the tool would evolve iteratively each year. The EPA would plan to release any revisions to the tool each year for public review and feedback and adjust the tool in advance of the next emissions inventory reporting deadlines. If the use of the tool changed, the EPA would update the training materials. This iterative approach would be coordinated with the ongoing iterative CAERS development approach that the EPA has been using very successfully for the past 3 years. The EPA would plan to funnel outreach for these efforts through SBEAPs within each state.
The EPA is considering how best to implement such an emissions estimation tool. Currently, the EPA is considering first ensuring that it includes key industrial processes that can be estimated at a facility level, relying on activity information that is readily available to small entities. Such industrial processes might be fuel combustion, solvent evaporation, and activities that create toxic dusts. Emission rates would depend on whether emissions controls are present and the type of controls if present. Emission factors would be used to translate some activity measure at a facility (e.g., fuel usage) to emissions. To use such an estimation tool, an owner/operator would need to (1) identify its emitting activities from a list that the EPA would provide and (2) enter total facility information for fuels, other materials, energy used, or other information that could even include the number of employees. The type of information used in the emissions estimation tool would depend on the available data for each emitting activity. The tool would show the estimated emissions levels and which ones (if any) were above the reporting thresholds.
The EPA is also considering the possibility of misuse of the tool by owners/operators to avoid reporting responsibility. For example, we have considered the possibility that an owner/operator might intentionally enter low activity data into EPA's tool to ensure emissions were below the applicable reporting threshold. The EPA's conclusion is that this would violate the requirement under §51.5(a) of this proposed rule to use the best available information to estimate emissions. Further, if the facility was actually emitting at or above the applicable reporting threshold but not reporting those emissions, that too would be a violation of the proposed requirements. The EPA plans to develop this tool to assist facilities with determining whether they emit at or above the applicable reporting threshold (and thus would be required to report) and to help them estimate emissions for reporting. Use of the tool, however, does not excuse an owner/operator, or a state, from complying with all applicable requirements. As part of using the tool, owner/operators would need to follow the directions provided as part of the estimation tool. The EPA also expects the tool would include a mechanism for users to indicate that the information entered is complete and accurate to the best of their knowledge. In addition, to avoid future misunderstandings, the tool would create an electronic report that would include the name and business of the person using the tool, the input data entered by the user, the resulting facility-wide emissions, and whether any of those emissions exceed an emissions reporting threshold. This information would not be collected by the EPA in the first instance, unless the report was submitted as an emissions report to the EPA either voluntarily or because the owner/operator has determined that it is required to report. However, we anticipate that future EPA directions, or guidance, associated with using the tool could recommend that owners/operators retain these reports and/or other information they used for assessing facility-wide emissions to determine whether they must report.
If a small business determines that emissions estimates exceed one or more HAP reporting thresholds, those facility-wide emissions could be reported to the EPA to meet reporting requirements, so long as the small business meets the conditions that permit optional facility-wide emissions reporting. The EPA intends to make the reporting of the tool emissions values easy for small entities by providing for an automatic transfer of information already entered into the emissions estimation tool into the CAERS reporting forms. This approach would further reduce burden on small entities. Finally, during any such submission, the EPA expects that CAERS would support an official certification that the information provided is complete and correct, consistent with EPA's certification requirements for electronic data collection.
14. Definition of Small Entities
To implement the small business accommodations described in section IV.A.12, the EPA is proposing a definition of small entity to be consistent with CAA Section 507(c). This definition limits small entities to those that meet all of the following criteria: (a) has 100 or fewer employees, (b) is a small business concern as defined in the Small Business Act (15 U.S.C. §631 et seq.), (c) is not a major source, (d) does not emit 50 tons or more per year of any regulated pollutant, and (e) emits less than 75 tons per year or less of all regulated pollutants. The SBA small business concern size standards are available at 13 CFR §121.201.
EPA is proposing this definition for two primary reasons. First, excluding major sources from the definition best supports the needs for data from major sources as previously described in sections IV.A.1 through IV.A.3. EPA's obligations under the CAA require process-level data from major sources, including control technologies employed. Using this definition, the proposed accommodations for small entities would not interfere with getting that necessary data from major sources.
Second, these proposed requirements are for record keeping and data reporting, which have much lower burden associated with each facility than would a proposal that includes requirements to install control devices. EPA's estimated yearly average per-facility burden for reporting emissions data starting in 2027, is just 27 hours when using in-house personnel to accomplish emissions reporting. This number of hours is reasonable given the information that would be collected and its importance to EPA analyses in support of the public interest. While still "small" under the SBA definition, larger facilities (i.e., those with more than 100 employees) could be more likely to emit pollutants at levels of environmental risk of concern and interest by EPA. The EPA would be able to use the additional process-level emissions data from these facilities to improve understanding of emissions from small entities at the process level and to include such sources in EPA's Technology Reviews.
Even so, the EPA is considering whether the CAA definition for small entities is the most appropriate because it does not provide as much burden reduction as would a definition based in part on the SBA definition. For the primary NAICS under consideration to define non-major sources for this proposal, the SBA definition includes owners/operators with between 200 and 1,500 employees, and for certain NAICS define small businesses based on the annual receipts of the company between $8 million and $41.5 million. As part of the SBAR Panel process, the EPA estimated the number of small entities that could be affected by the rule using a definition based on 100 employees for all NAICS codes as compared to a definition based on the SBA NAICS-specific thresholds. More details on the analytical approach are available in the supporting materials to the SBAR Panel Report included in the regulatory docket for this proposal. The EPA updated the SBAR Panel analysis with the final NAICS and reporting thresholds included in this proposal, and the analysis results are included in the TSD for this proposal. Through this analysis, the EPA estimates that using a definition of 100 employees would require reporting for about 34,000 small entities, allowing them to use the proposed small business accommodations. That same analysis estimated that using the SBA small entity definition would require reporting from about 43,000 small entities. This analysis is limited by the available data because the 100-employee threshold that is used to represent the CAA small entity definition does not reflect the exclusion of major sources or the emissions-based criteria that are part of the CAA definition. As such, EPA's estimate of 34,000 most likely overestimates the number of additional small entities that would be subject to the proposed AERR revision, in part because some major sources are also small entities.
Given this information, the EPA is considering a "SBA Definition Alternative" that would modify the proposed definition to replace the 100-employee threshold with the NAICS-based thresholds available from the SBA definition. This alternative would still exclude major sources from being within the definition of small business but would include more non-major small entities in the definition. The EPA encourages commenters to provide information about benefits of the reduced burden on more owners/operators in comparison to the reduced data detail that the EPA would have available to estimate risks and analyze for purposes including Technology Reviews.
15. Reporting HAP and CAP for the Same Emissions Processes
Under the current AERR relying on voluntary HAP reporting by states, the EPA has observed that some states report CAPs and HAP using separate unit and/or process identifiers for pollutants emitted from the same process. For example, a state could report emissions for a boiler burning oil using process identifier "1" to report VOC and process identifier "2" to report benzene, when in fact both pollutants are emitted from the same process and therefore should use the same process identifier. Downstream analytical steps that utilize emissions inventories rely on computer processing because of the hundreds of thousands to millions of data records included in point source inventories. The computer software uses the process identifier as one of the unique emissions source identifiers. In this example, the software would treat the VOC and benzene as if they were emitted from two sources at the facility, rather than from a single process for the boiler.
For many uses of emissions inventories, inconsistent process-level identifiers pose no problem, but the situation can create some problems. First, it complicates QA of the inventory, such as identifying whether certain expected pollutants may be missing from processes and ensuring that the inventory includes consistent information across pollutants for the same process, such as the source classification code (SCC). Second, using different SCCs for the CAPs and HAP emitted from the same process (but not reported at the same process) could cause a miscalculation of co-pollutant impacts from emissions controls. For example, when a computer program processes an emissions inventory for control strategy development, that program would not recognize that a VOC emissions control device assigned at the process level should also impact the benzene emissions because benzene is a part of VOC. This problem could occur due to mismatched process identifiers, SCCs, or both. Third, chemical speciation calculations on emissions inventories can be adversely affected by inconsistent process-level reporting, because HAP emissions can be used to improve the chemical species of CAPs for use in models. Using the VOC and benzene example, when the VOC and benzene are reported with different processes, then the computer software could not use the reported benzene to inform the chemical speciation of the VOC from the same process.
To address these considerations, the EPA proposes to include, at 40 CFR 51.40(b), a provision stating that when reporting process-level emissions data, states and owners/operators would be required to use the same unit, process, and release point identifiers for all pollutants emitted from the same unit, process, and release point at the facility. Such an approach allows inventory users to better understand the full suite of pollutants for each process, enabling improved ability to consider ancillary benefits or the potential for unintended adverse impacts of controls on co-pollutants from the same process.
To address the recommendations of the SBAR Panel Report, this proposed requirement would not apply to small entities that elect to report HAP emissions as a facility total as per the proposed accommodations described in section IV.A.12. In this case, small entities would not report HAP at the process level and the need for a process identifier would not apply. Thus, if a facility owned by a small business meets the AERR CAP reporting thresholds, then a state would need to collect CAPs from the small business and report them to EPA. If the state collects HAP on behalf of the same facility in accordance with these proposed requirements, then the EPA is proposing that the state would need to allow the small business to report HAP as a facility total. However, if the state collects HAP on behalf of the facility and the state reporting requirements include mandatory process-level reporting (i.e., going beyond these proposed requirements), then the state would be expected to report the process-level emissions to EPA.
16. Option to Include PFAS as a Required Pollutant
The EPA is considering whether this action should include reporting of per- and polyfluoroalkyl substances (PFAS). PFAS compounds are persistent in the environment and accumulate in body tissues, and exposure to PFAS compounds has been linked to adverse health effects in humans and animals. There are currently no health benchmarks for the inhalation toxicity of PFAS compounds; however, PFAS point source emissions into air can deposit PFAS into nearby drinking water bodies. The EPA has derived chronic, noncancer reference doses (RfD) for oral exposure to perfluorooctanoic acid, perfluorooctyl sulfonate, GenX, and perfluorobutane sulfonate, with assessments for several additional PFAS compounds in progress. While PFAS are not currently HAP, current evidence suggests a need for better identification and characterization of PFAS point source emissions in air.
The EPA's 2021 PFAS Strategic Roadmap tasked the Office of Air and Radiation with building the technical foundation to address PFAS air emissions, in part by identifying PFAS sources and developing monitoring approaches for stack emissions. Certain PFAS were added to the TRI chemical list under Section 7321 of the National Defense Authorization Act (NDAA) for Fiscal Year 2020. The NDAA sets the reporting threshold for individual PFAS compounds at 100 pounds (i.e., 0.05 tpy). As previously described for HAP, TRI does not provide the level of detail needed for detailed modeling for PFAS.
EPA also is considering the limitations in our understanding of PFAS. For example, measurement methods are unavailable to measure many of the individual compounds making up the collective group of PFAS compounds. While the EPA continues to develop additional measurement methods and more such methods will be available over time, they are not available currently. Additionally, toxicity data are available for only a handful of compounds in this group currently, but ongoing EPA work in this area is expected to provide additional toxicity data in the future. These limitations would need to be accommodated by any regulations concerning the reporting of PFAS. For example, while the EPA has done risk analysis to support the threshold levels for reporting HAP (described in IV.A.8), the EPA does not, at this time, have sufficient PFAS and risk data to use a similar approach for PFAS. The Agency must therefore find another approach to propose reporting thresholds for PFAS if it were collected under this subpart. As with other pollutants as described in Sections A.4 and IV.I.6 of this preamble, EPA is proposing that owners/operators would not need to measure PFAS emissions if measurements were not already available. Rather, owners/operators would be required to use PFAS source measurements for annual emissions reporting purposes when available and use estimation techniques for reporting when measurements are not available.
Given these considerations, the EPA seeks comment on the following "PFAS Option" for how the Agency could include PFAS reporting requirements in a final action. Regulatory text to implement this option is described and included here in the preamble. First, the title of proposed 40 CFR 51.12(b) would be changed to "Hazardous air pollutants and Per- and Polyfluorinated Substances."  Second, EPA would include at the end of proposed 40 CFR 51.12(b)(1) "and PFAS as listed in Table 1E to Appendix A of this subpart." The EPA would additionally add Table 1E to list the PFAS subject to reporting, consistent with the PFAS list included as part of the TRI. The EPA would further add paragraph (3) to proposed 40 CFR 51.12(b) to read "For point sources other than major sources, reported PFAS must include any pollutant listed in Table 1E to Appendix A of this subpart when the annual actual emissions of that pollutant or pollutant group is greater than or equal to the PFAS reporting threshold." The threshold would be 0.05 tpy of total emitted PFAS-based on the TRI requirements set by Congress. Finally, the EPA would change proposed 40 CFR 51.15(1) to read "If the EPA has approved a HAP and PFAS reporting application as per §51.1(d)(2) and §51.1(d)(3) of this subpart, a state must report emissions of HAP and PFAS consistent with §51.12(b) and (c) of this subpart. A state may report one or more HAP or PFAS voluntarily through the 2025 inventory year and may not report HAP or PFAS without an approved application starting with the 2026 inventory year."
The EPA recognizes that aligning with the TRI requirement sets a reporting threshold for the purposes of the AERR that uses the same value for a different purpose, because the TRI reporting threshold is based on single PFAS manufacturing, processing, and otherwise use of the given PFAS and therefore may not capture emissions from sources with cumulative PFAS emissions in air greater than or equal to 0.05 tpy. Nevertheless, this PFAS Option, if included in the final rule, would set an air emissions reporting threshold at the 0.05 tpy level.
By proposing this threshold for the AERR, the EPA is aligning the thresholds as best as possible to reduce complexity and burden. The EPA's proposed approach for the AERR is a less stringent threshold than the TRI threshold because facilities that manufacture, process, or otherwise use PFAS would likely not emit all of that material to the air. As such, the EPA is not adding any burden on facilities to recognize that they may need to report to the AERR, but rather to estimate their PFAS emissions at the level of detail proposed. Collecting PFAS emissions data using these proposed requirements could be a step towards meeting OAR's goals from the EPA PFAS Strategic Roadmap. The EPA is soliciting comment on the PFAS option for including mandatory reporting on PFAS in the final rule.
B. Collection of Emissions from Point Sources Not Reported by States
The EPA's mission includes protecting human health and the environment for the entire population, and emissions inventory data are a foundational piece of such work. To meet this mission, the EPA intends for the NEI to be a complete accounting of emissions from all facilities that meet the point source reporting thresholds defined by this subpart; however, this objective cannot be met when certain facilities are not included. Furthermore, the communities near such facilities may not have equitable access to emissions data about those facilities when compared with other communities. The EPA cannot account for the impacts of those sources on their communities without the same detailed emissions data as is available for other sources. The EPA has identified cases in which point source emissions are not included in the NEI, even though their PTE or actual emissions exceed the CAP reporting thresholds in the current AERR. In all cases, the EPA proposes that owners/operators would report both HAP and CAP data to the EPA under this subpart. The HAP reporting provisions described in Section IV.A apply to such owners/operators; therefore, this section addresses several cases where CAP emissions would also need to be reported and clarifies reporting requirements for facilities operating in Federal waters.
The EPA is proposing regulatory revisions to address these issues for two reasons. First, the EPA created the NEI program using input from many stakeholders and is considering updates to the AERR based on additional input. For example, the EPA Regional offices have noted the lack of emissions data in some areas of Indian country and the resource challenges that some tribes have, which make it difficult for a tribe to apply for TAS or to collect emissions data. Regional offices adjacent to areas of Federal waters with offshore oil activity, fish processing ships, deep water ports, and wind turbine construction have also noted the lack of emissions data for those activities. Second, the cases of missing facilities described above impede the ability of the Agency to meet its mission because it does not have the foundational data about emissions sources necessary to assess impacts from those sources, among other limitations. In addition, since emissions from more sources could be reported because of the HAP requirements of this proposed action, the problem of missing sources could expand if not addressed by this proposal.
1. Facilities on Land Not Reporting Under the Current AERR
As previously described in Section III.A.3, some facilities are not reported because the facility is not located within the geographic scope of the state's (defined previously in this preamble to include local agencies and tribes that have obtained TAS for submission of emission inventories) implementation planning authority. This can occur, for example, for a facility that operates within an Indian reservation for a tribe that has not obtained TAS for submission of emission inventories.
States may not report certain other facilities when EPA issues a federal permit, even though the facility is located within the geographic scope of a state's implementation planning authority. When the state has developed its emissions inventory collection program based on only those facilities for which the state issues operating permits, the state or local agency might assume that it is not obligated to report the emissions because it has not permitted the source.
The primary challenge with collecting data from such sources under the current AERR is that reporting is only provided from states. The reported emissions data are, therefore, somewhat limited to what states collect and report. In the case of facilities that are located on lands outside the geographic scope of a state's implementation planning authority and are rightly not reported by a state, the current AERR structure does not provide a mechanism for collecting that data.
For facilities that have EPA-issued, rather than state-issued, operating permits, the EPA has evaluated the current AERR to determine if states are correct when they do not report emissions data for these facilities. The existing version of this subpart says at 40 CFR 51.15(b) that "[e]missions should be reported from the following sources in all parts of the state, excluding sources located within Indian country." This language suggests that there is no exemption for sources where the state does not issue an operating permit. Additionally, 40 CFR 51.25 reads "[b]ecause of the regional nature of these pollutants, your state's inventory must be statewide, regardless of any area's attainment status." Further review of the current AERR finds no exemptions for facilities that are not permitted by the state. As a result, the EPA does not need to propose any additional requirements in this action for states reporting CAPs. However, to ensure clarity with regards to the existing requirements, the EPA proposes to add the clarification to §51.1(c)(1) of this subpart that "a lack of state permitting for point sources or pollutants associated with them does not exempt a facility or pollutant from being reported by the state."
In the case of sources missing from the inventory because the facility is located outside the geographic scope of a state's implementation planning authority, the owner/operator reporting approach of this proposed action, described in section IV.A.5, already provides for reporting HAP and incidental CAPs directly from owners/operators of those facilities. This requirement has not been previously included in the AERR. To resolve the problem of missing sources from the NEI, the only additional requirement needed in this proposed action would be to require owners/operators to report CAP emissions to the EPA for facilities that meet the CAP reporting thresholds in Table 1A to Appendix A of this subpart, and that are within Indian country where not already reported by a tribe or state.
The EPA is also considering those owners/operators of certain sources located within an Indian Reservation in Idaho, Oregon, and Washington who must register and report certain emissions data to EPA Region 10 under 40 CFR 49.138. This regulation is part of a set of regulations that have been incorporated into federal implementation plans for 39 Indian reservations for those three states. The set of regulations is known as the Federal Air Rules for Reservations (FARR) in Idaho, Oregon, and Washington. The EPA has proposed revisions to the FARR on October 12, 2022 (87 FR 61870), and the EPA has also considered these proposed changes in relation to the proposed requirements of the AERR. The current requirements specify at §49.138(b) that it applies to "any person who owns or operates a part 71 source or an air pollutant source that is subject to a standard established under section 111 or section 112 of the Federal Clean Air Act." The rule also applies to other owners/operators of air pollutant sources including sources that have a PTE of 2 tpy or more of any air pollutant, except for sources meeting criteria for a significant list of exemptions.
Under the current and proposed FARR registration rule, the owners/operators subject to the requirements of §49.138 must register their air pollution source with the Regional Administrator of EPA Region 10 (initially and annually) with specific requirements for information to be included in such registration. The provision for registration includes reporting of information to the Regional Administrator that is very similar to the facility inventory and annual emissions reports included in this proposal. Emissions reporting under §49.138 is limited to Particulate matter, PM10, PM2.5, SOX, NOX, CO, VOC, Pb, NH3, fluorides (gaseous and particulate), sulfuric acid mist (H2SO4), hydrogen sulfide (H2S), total reduced sulfur (TRS), and reduced sulfur compounds, including all calculation for the emissions estimates. The requirements include specific provisions, similar to section IV.A.6 of this preamble, that specify the priority of which emissions estimation approaches should be used. This existing rule requires additional activities, the specifics of which are not critical to this preamble. While the current rule does not include any specific electronic submission or formatting requirements, for the past 7 years sources have been voluntarily submitting their registration and emissions reports through an electronic reporting system called the FARR Online Reporting System (FORS). The revisions proposed to 40 CFR 49.138 included requiring electronic reporting via FORS.
In comparison to the requirements of this proposal, 40 CFR 49.138 impacts the same major sources within the affected Indian country. In addition, 40 CFR 49.138 would impact some of the same non-major sources covered by this proposal because the 2-ton PTE reporting threshold in that rule is much lower than the major source PTE thresholds for CAPs and actual emissions thresholds for HAP in this proposal. Without creating a limited exception within this proposal, those sources would have duplicative requirements since many of the pollutants required in that rule overlap with pollutants the EPA is considering requiring under this subpart. Lastly, there are differences in the pollutants being reported between 40 CFR 49.138 and this proposal because (1) this proposal does not include reporting of emissions of fluorides, H2SO4, H2S, TRS, or reduced sulfur compounds, and (2) this proposal includes many more HAP than are required under that rule.
As a result of these considerations, this action proposes to require owners/operators of facilities located within Indian country and not being reported by a tribe or state to report all CAPs directly to EPA when the PTE or actual emissions of one or more such pollutant exceeds the reporting thresholds in Table 1A to Appendix A of this subpart. This requirement is complementary to the previously described HAP reporting requirements. For facilities meeting the CAP PTE thresholds, owners/operators would need to report all CAP pollutants and the incidental CAP requirement would not be relevant to those facilities.
To avoid unnecessary burden for owners/operators of facilities for which emissions data must be reported to the EPA under 40 CFR 49.138 as described above, the EPA also proposes that certain owners/operators would be exempt from the requirements of this subpart for reporting emissions of any pollutants already being reported under 40 CFR 49.138. The EPA additionally proposes that owners/operators in that situation may, at their option, report such exempt pollutants to the EPA electronic reporting system along with any information that is required to be reported under this subpart. The limited exemption to the AERR requirements would only apply to data that are already being reported to the EPA under 40 CFR 49.138 for facilities on Indian reservations in Idaho, Oregon, and Washington. If a facility is subject to requirements in the AERR and 40 CFR 49.138, then the owner/operator of that facility would still be required to report under the AERR for those data that are not reported under 40 CFR 49.138.
While the proposed approach avoids some duplication of burden, the EPA recognizes a different approach could further reduce duplicative reporting. The EPA intends to adapt CAERS so that it would allow emissions reporting to the EPA through CAERS to meet the compliance requirements of 40 CFR 49.138. To do this, the EPA would ensure that all elements of 40 CFR 49.138 would be met as part of electronic reporting via CAERS. Once EPA develops and provides a CAERS compliance approach for owners/operators to meet reporting requirements of 40 CFR 49.138, EPA expects that CAERS would replace the current FORS data collection system.
2. Facilities within Federal Waters
Under the current AERR, states are not obligated to report emissions from offshore facilities operating in Federal waters because states generally do not have jurisdiction over such sources. The EPA has jurisdiction over certain air emissions activities within Federal waters, including OCS sources subject to regulation under CAA Section 328. To address this gap in emissions data, the EPA is proposing provisions to address: (1) which owners/operators of facilities in Federal waters would need to report, (2) what data would need to be reported, and (3) how that data should be reported. The EPA is requesting comment on whether these reporting requirements would be duplicative.
First, regarding which owners/operators operating in Federal waters would report under this proposed action, the EPA is aware that many facilities already report emissions data to the Bureau of Ocean Energy Management (BOEM), which in turn reports these data to EPA. To avoid such facilities being subject to AERR requirements, the EPA proposes at §51.1(a)(2) that owners/operators would be required to report for facilities that operate within Federal waters, including (1) deepwater ports subject to CAA requirements under the Deepwater Port Act, and (2) 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 (i.e., offshore Texas, Louisiana, Mississippi, and Alabama).
Second, the EPA is considering which data would need to be reported by owners/operators of these facilities. Many OCS sources and other facilities in Federal waters are subject to the requirements of Federal or state title V operating permit programs that contain emissions reporting requirements and, in some cases, require permittees to annually quantify actual emissions for purposes of calculating permit fees. For those facilities subject to title V emissions reporting and/or emissions quantification requirements, the EPA proposes that owners/operators should use the same approaches to identify the emissions sources of such facilities and to estimate and submit emissions data under this subpart. Emissions sources at such facilities may include portable sources (e.g., drill rigs), operation of units that, if on land, would be stationary sources (e.g., boilers, control devices, chemical processing equipment, refrigeration units), and marine vessels (e.g., engines that power the movement of service vessels within 25 miles of an OCS source, and marine vessel engines used for other purposes when stationary).
In addition, the EPA proposes to require owners/operators of facilities in Federal waters (as described above) to report all CAPs when the PTE or actual emissions of one or more such pollutant exceeds the reporting thresholds in Table 1A to Appendix A of this subpart. This requirement is complementary to the previously described HAP reporting requirements. For facilities meeting the CAP thresholds, owners/operators would need to report all CAP pollutants and the incidental CAP requirement would not be relevant to those facilities.
Third, the EPA is assessing how these owners/operators should report emissions data. In addition to meeting the other point source reporting requirements under this subpart, the EPA proposes a requirement for facilities operating in Federal waters to report emissions using the Federal waters region codes provided in the EPA electronic reporting system. Because these Federal water regions are extremely large, the EPA expects that most facilities will only operate within a single area, but when portable facilities operate in multiple areas of Federal waters, owners/operators would need to report those emissions separately with different Federal waters region codes.
Lastly, to support this proposed approach, the EPA further proposes the definition of Federal waters to mean those waters over the "Outer Continental Shelf" as defined in the Outer Continental Shelf Lands Act (43 U.S.C. §1331(a)).
The EPA also recognizes the possibility of duplicative reporting related to any reporting that may be required by permits and/or for assessing title V permit fees. To help avoid duplicative burden, the EPA urges commenters to describe any duplicative burden that this proposal may cause for emissions reporting.
C. Source Test Reporting
To improve the data available to the EPA, states, and sources to estimate emissions, the EPA proposes to require electronic source test reporting (as first explained in Section III.A.3 of this preamble) from point sources for certain source tests. This action would require such reporting for source tests already required to be performed, to help improve emissions factors. An emissions factor is a key tool used in the creation of emissions inventories, for example, to estimate air pollutant emissions from a normally operating, point-source process or activity (e.g., fuel combustion, chemical production). An emissions factor relates the quantity of pollutants released to the atmosphere from a process to a specific activity associated with generating those emissions. For most application purposes, emissions factors are intended to represent the average emissions for all emitting processes of similar design and characteristics (i.e., the emissions factor represents a population average). As such, emissions factors provide an emission rate that may be appropriate for use by owners/operators of facilities when site-specific source measurements of an emission process are not available. While greater uncertainty is associated with use of emissions factors as compared to site-specific source measurements, it is nevertheless important to ensure that emissions factors are high quality.
EPA's most recent approach to develop emissions factors has been prepared in response to a review of EPA's emissions factors program by the National Academy of Sciences and EPA's Office of Inspector General. In 2006, that review resulted in the Inspector General report previously referenced in section IV.A.3 of this preamble. As described in EPA's most recent documentation on emissions factor calculation procedures, the EPA revised its emissions factor calculation approach in response to that report. The EPA's emissions factor procedures rely on direct measurement of releases from point source processes or activities (i.e., a sample of the process emissions is collected and analyzed). Hereafter, such measured emissions data from a source will be referred to as "source test data." EPA's progress on improving emissions factors is limited to the available source test data received by the Agency.
As previously described in section IV.A.4 of this preamble, this action proposes to require emissions reporting of annual total HAP from owners/operators. The benefit of this HAP emission collection program, however, depends on the quality of the annual emissions data reported by owners/operators of facilities. The quality of the annual emissions totals depends in part on the availability and quality of the emissions factors, which in turn depend on the availability and quality of HAP emissions source test data.
While the Inspector General report highlighted the lower-than-desired quality of published emissions factors, the EPA has thus far been unable to revise many of these factors and continues to be limited in part by the lack of source test data. This limitation remains despite EPA's efforts to revise its regulatory framework of stationary source emissions reporting to include electronic source test data reporting as a component of industry-specific regulations included in 40 CFR Parts 60, 61, 63, etc. The pace of progress on improving these factors to date has been limited in part by the gradual nature of adding industries and pollutants one regulation at a time. In addition, since those regulations address specific pollutants and, in some cases, allow for reporting of emissions of one pollutant (such as filterable PM2.5) to serve as a surrogate for other pollutants (such as specific HAP metals), sources do not always conduct tests for, and the EPA does not receive data for, non-surrogate pollutants.
In addition to the recommendations of the Inspector General Report, states have long expressed their concerns with the many missing emissions factors in addition to the low-quality emissions factors included in EPA's AP-42 and WebFIRE emissions factor compilations. These state concerns have been compiled and included in the docket for this proposed action. Despite these concerns, these emissions factor compilations largely remain a foundational piece of emissions inventories. The states and the CAERS application use AP-42 and WebFIRE emissions factor data to support owners/operators of facilities by providing the emissions factors directly within the emissions calculation tools used during emissions reporting. While owners/operators are expected to use site-specific source test data to calculate and report emissions when available and appropriate for that use, the emissions factors are often the only emission rate information available. Thus, improving the quality of the emissions factors is central to improving emission inventory quality overall.
With this proposed rulemaking, the EPA is seeking to improve emissions factors to support improved emissions inventories via the proposed collection of additional source test data. The EPA has recently completed the updates to the WebFIRE system that automates most of the emissions factor development processes described by the emissions factor procedures document previously mentioned. As a result of these efforts, the EPA issued its first set of revised emissions factors for public review in November 2021. Now that the development procedure infrastructure is largely completed, the EPA finds that increasing the amount of source test data by obtaining information from the thousands of emissions processes and hundreds of pollutants included for stationary sources in the NEI is a logical progression in emissions factor improvement. By improving emission factors, emissions estimates are improved as well, supporting the needs for high quality data to support EPA's regulatory and non-regulatory activities as described in Section IV.A of this preamble.
To assess the feasibility of further collection of source test data and gathering information to design the proposed approach, the EPA is considering (1) whether source test data are readily available or could be readily available, (2) how such data could be collected electronically and efficiently, (3) which existing data would be of interest to the agency, and (4) how to phase in any new reporting requirements.
The EPA is aware that direct measurements of facility or process emissions are conducted for a variety of reasons, including characterizing process emissions and/or control device performance, assessing changes in process or control device operation on emissions, and demonstrating compliance with Federal, state, local, or tribal air regulations. Emissions testing may also be conducted as part of performance evaluations such as relative accuracy test audits (RATAs). Performance evaluations include linearity checks (which measure an instrument's ability to provide consistent sensitivity throughout its operating range) and routine calibrations of continuous emissions monitoring system (CEMS) equipment, which provide emissions data much more frequently than testing. Emissions data from CEMS are mostly used for compliance purposes but can also be used for emissions factor development. The reasons why such testing and evaluation occurs includes both the CAP and HAP aspects of air quality planning and implementation. Thus, these activities are conducted for a larger range of pollutants than would be available from reporting required by regulations under 40 CFR Parts 60, 61, and 63, including those that have been updated for electronic reporting and those that continue to require testing and reporting by other means. Based on this information, it appears to the EPA that additional unreported test data are readily available.
To aid owners/operators in planning and reporting the results of emissions tests, the EPA developed the Electronic Reporting Tool (ERT), and CEDRI. Further, the EPA has required their use in the revised regulations previously described. The ERT is used by companies that perform emissions testing for industrial sources and has been in use for over 10 years. As the EPA has promulgated regulations to require electronic reporting with the ERT, it has modified the ERT and CEDRI to make sure that they support the source measurement methods required by those regulations. As a result, the EPA has been collecting source test data for selected pollutants from facilities regulated by those revised rules for many years. The ERT and CEDRI collection infrastructure, in addition to the recently implemented WebFIRE emissions factor calculation procedures, will help ensure an efficient approach for data collection and emissions factor development.
Information collected by the EPA from the companies that perform source measurements for industrial sources supports the idea that electronic reporting for all pollutants via the ERT is commonly supported by these companies. The EPA understands that it would be rare to find any of these companies unfamiliar with the reporting via the ERT. Some of our experience suggests that companies may find it more difficult and more costly to prepare and submit reports in hard copy (i.e., paper test reports) rather than reporting electronically, since much of the data collection process has been made electronic.
The EPA also is considering whether source test data should be reported to the EPA directly by owners/operators or via the states. States currently collect some test data as part of their implementation of source permits and compliance, for example, when states require such tests for their own reviews of emissions from stationary sources. Given this current reporting, it is reasonable to expect that some states may want to provide source test data to EPA. Such an approach might parallel reporting that is currently done for CAP emissions and can be done for HAP emissions. Including states in such reporting could have the advantage of potentially meeting the needs of those states that wish to be intermediaries or review the facility source test prior to it being reported to the EPA for use in emissions factors.
The possible disadvantage of states reporting the source test data could be the added complexity that such an approach may cause. With the existing CEDRI approach currently in place, states have a period during which they may optionally review the source test results and advise the EPA regarding the validity of the source test and any data quality concerns that the state may have. In addition, when current EPA regulations require source tests, they require that data to be reported directly from owners/operators of stationary sources. Any difference that might be proposed from that current approach could have a further disadvantage of causing inconsistencies for owners/operators in how to report source test data. Specifically, reporting under such an approach could depend on whether the requirement to report for a pollutant and process was under any finalized version of this proposed action or under one of the other subparts of 40 CFR that require such reporting. As a result of these significant disadvantages, the EPA expects that any proposed action would be most efficiently and effectively implemented through direct reporting of source test data to the EPA from owners/operators and continuing to allow for state review and comment.
The EPA has additionally reviewed the requirements of the ERT to ensure that the data collected with the ERT would be sufficient for the purpose of generating emissions factors. To be able to use the source test data for purposes of emissions factors, the EPA has identified four additional types of information that are necessary to provide a complete characterization of a unit's emissions in relation to its operation. These are (1) the capacity of the unit being tested, (2) the load of the unit during the testing period, (3) the level of activity of the unit and operating conditions of the unit during the testing period, and (4) process data (e.g., temperatures, flow rates) pertaining to the unit and its control devices during the testing period. All four of these are key components to ensuring emissions factors appropriately represent unit operation. For example, NOX emission rates from a unit operating at 50 percent load using natural gas with 50 gallons per hour of ammonia injection differ from a unit operating at 95 percent load using fuel oil with 75 gallons per hour of ammonia injection. As a result, correctly computed emissions factors from these separate modes could differ as well. Without the full information, the EPA may not be able to discern the differences in unit operation and incorrectly combine source test data, which could lead to emissions factors erroneously assigned to certain combinations of units, processes, and controls.
As a result of these considerations, the EPA proposes to require owners/operators of point sources to report performance test results and performance evaluations that meet the following conditions: (1) data would only be reported (under this proposed rulemaking) when they are not otherwise reported to the EPA based on regulations listed at https://www.epa.gov/electronic-reporting-air-emissions/cedri#list; (2) the data are gathered to meet any other EPA or state requirement; (3) the data are supported for reporting by CEDRI or an analogous electronic reporting system; and (4) the results were not from a project, method, device, or installation (or any component thereof) that was produced, developed, installed, and used only for research purposes. This final criterion was added to avoid any potential conflict between the definition of confidential data and the treatment of "emission data" in accordance with 40 CFR 2.301. More information on the issue of confidential data for this proposed action is available in section IV.H of this preamble.
The EPA is seeking comment on these criteria. Specifically, the EPA would be interested in knowing of examples of tests that meet these criteria but which do not meet the EPA's objective as described in this section to support emissions factors. If such examples exist, the EPA is further interested in suggestions of how to revise, or supplement, the criteria to avoid collecting such information that does not meet the objective of this section.
Additional aspects of EPA's proposed approach to collect source test data include the following. The proposed reporting, if finalized, would be limited to include source tests and performance evaluations beginning on the effective date provided in the final rulemaking. It would require submission of data via CEDRI, including the four types of information as previously noted: (1) capacity of the unit being tested, (2) the load of the unit, in terms of percent capacity, during the testing period, (3) 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), (4) operating conditions of the unit during the testing period, and (4) process data such as temperatures, flow rates, pressure differentials, pertaining to the unit and its control devices during the testing period. The ERT would need to be used when it supports the source test or performance evaluation and, in other cases, a spreadsheet-based approach could be required. Finally, each report would need to be submitted by the scheduled date required by the state or Federal action motivating the test. When no such date exists, the report would be required within 60 days of completing the source test or performance evaluation.
D. Reporting for Certain Small Generating Units
With this proposed rulemaking, the EPA seeks to solve long-standing challenges associated with emissions from certain types of intermittent combustion sources. Interest in emissions and ozone formation on high energy demand days (HEDDs) has led the EPA to consider collecting information from sources that operate to offset electricity demand from the electricity grid during these times. The EPA already collects detailed data from EGUs through the Clean Air Markets Program, which requires reporting of hourly data from CEMS as specified by 40 CFR Part 75. In addition to these sources, other electricity units including small generating units (less than 25 MW or otherwise not subject to reporting under 40 CFR Part 75 or the mercury air toxics NESHAP at Subpart UUUUU of 40 CFR Part 63) and backup generators (BUGs) are run periodically both to offset grid-based energy needs at energy intensive facilities and to generate electricity for the grid. These sources may contribute significantly to tropospheric ozone on high-temperature days in some areas, leading to public health concerns. As climate change is expected to result in warmer summers, the use of this distributed generation could increase. While such data are important to better understand the environmental impacts of these sources, the EPA is not currently collecting such data from states or owners/operators.
Without data collection, EPA's understanding of these sources is limited. First, the EPA lacks important details about intermittent activity of these sources. For understanding ozone impacts, the EPA and states have a compelling need to know when emissions occur on a finer temporal resolution than typical annual emissions (i.e., which days). Without such information, past studies have shown that efforts to model HEDDs fail to fully characterize ozone formation on such days.
Second, the EPA has reason to question the emission rates that would be appropriate for estimating emissions from such sources. Existing emission rates (i.e., emissions factors) for all units of any type are based on emission source testing methods that are correctly used during steady state operation of the emission unit to achieve valid emission tests. By contrast, the operation of these intermittent sources means that they are frequently turned on and off, which has an unknown impact on the resulting emissions. As an illustration of the issue, it is common knowledge that engines run more efficiently (thus more cleanly) once they have warmed up. To the extent that units run periodically spend more time in an inefficient state of operation, they would be expected to have higher emissions rates. However, the impact of such operation is not well understood, and the EPA is not aware that it has been quantified.
Over the past two decades, states and multi-jurisdictional organizations have discussed with the EPA the possible importance of intermittent sources on air quality. While some proposals have been put forward to reduce the problem of emissions from these types of intermittent units, the full understanding of the problem has been limited based on lack of available data.
In a 2017 publication, researchers from the University of Wisconsin-Madison linked peak electricity demand to high levels of air pollution. Using data collected from 27 states between 2003 and 2014, the researchers showed that the electricity used to power air conditioners increased emissions of SO2, nitrogen oxides, and carbon dioxide (CO2) by an average of almost four percent for each pollutant per degree Celsius increase, above a certain reporting threshold.
While they have received more attention in recent years, emissions from these small generating units have been historically challenging to track, a fact that has contributed to EPA's aim to understand and improve the data in this sector. The EPA recognizes that emissions from small generating units may increase as extreme weather and temperature events are likely to become more frequent. Alongside this potential rise in emissions are increases in public health risks from tropospheric ozone formation, as well as nitrogen oxides and PM emissions.
As a result of past investigations, some states have explored how they can gather information about intermittent sources. For example, the Maryland Department of Environmental Quality (MDEQ) requires that Curtailment Service Providers (CSPs) provide data to the state under COMAR <IP_ADDRESS>. CSPs are entities that administer electricity demand response programs by working with companies that use and generate electricity to decrease electricity demand by deploying capacity from smaller units like BUGs that can reduce demand from the electricity grid. The Maryland regulation requires CSPs to report information about the units they administer, including unit capacity, manufacturer, and model as well as the types of fuel used and information about the days and hours of operation. It also sets an exclusionary threshold based on output. It excludes emergency stationary engines with an output less than 500 horsepower (hp) and excludes non-emergency stationary engines with an output less than 500 hp that serve as a primary source of power for agricultural equipment or industrial equipment. While this information only partially addresses the needs for the state, discussions with MDEQ identified that the information collected has helped the state understand the scope of the intermittent unit emissions. This example provides some evidence that partial data collection can inform the larger temporal patterns in emissions associated with intermittent sources.