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Electronic Code of Federal Regulations

e-CFR Data is current as of March 26, 2015

Title 40Chapter ISubchapter CPart 51 → Subpart A


Title 40: Protection of Environment
PART 51—REQUIREMENTS FOR PREPARATION, ADOPTION, AND SUBMITTAL OF IMPLEMENTATION PLANS


Subpart A—Air Emissions Reporting Requirements


Contents

General Information for Inventory Preparers

§51.1   Who is responsible for actions described in this subpart?
§51.5   What tools are available to help prepare and report emissions data?
§51.10   [Reserved]

Specific Reporting Requirements

§51.15   What data does my state need to report to EPA?
§51.20   What are the emission thresholds that separate point and nonpoint sources?
§51.25   What geographic area must my state's inventory cover?
§51.30   When does my state report which emissions data to EPA?
§51.35   How can my state equalize the emission inventory effort from year to year?
§51.40   In what form and format should my state report the data to EPA?
§51.45   Where should my state report the data?
§51.50   What definitions apply to this subpart?
Appendix A to Subpart A of Part 51—Tables

Source: 73 FR 76552, Dec. 17, 2008, unless otherwise noted.

General Information for Inventory Preparers

§51.1   Who is responsible for actions described in this subpart?

States must inventory emission sources located on nontribal lands and report this information to EPA.

§51.5   What tools are available to help prepare and report emissions data?

(a) We urge your state to use estimation procedures described in documents from the Emission Inventory Improvement Program (EIIP), available at the following Internet address: http://www.epa.gov/ttn/chief/eiip. These procedures are standardized and ranked according to relative uncertainty for each emission estimating technique. Using this guidance will enable others to use your state's data and evaluate its quality and consistency with other data.

(b) Where current EIIP guidance materials have been supplanted by state-of-the-art emission estimation approaches or are not applicable to sources or source categories, states are urged to use applicable, state-of-the-art techniques for estimating emissions.

§51.10   [Reserved]

Specific Reporting Requirements

§51.15   What data does my state need to report to EPA?

(a) Pollutants. Report actual emissions of the following (see §51.50 for precise definitions as required):

(1) Required pollutants for triennial reports of annual (12-month) emissions for all sources and every-year reports of annual emissions from Type A sources:

(i) Sulfur dioxide (SO2).

(ii) Volatile organic compounds (VOC).

(iii) Nitrogen oxides (NOX).

(iv) Carbon monoxide (CO).

(v) Lead and lead compounds.

(vi) Primary PM2.5. As applicable, also report filterable and condensable components.

(vii) Primary PM10. As applicable, also report filterable and condensable components.

(viii) Ammonia (NH3).

(2) A state may, at its option, choose to report NOX and VOC summer day emissions (or any other emissions) as required under the Ozone Implementation Rule or report CO winter work weekday emissions for CO nonattainment areas or CO attainment areas with maintenance plans to the Emission Inventory System (EIS) using the data elements described in this subpart.

(3) A state may, at its option, choose to report ozone season day emissions of NOX as required under the NOX SIP Call and summer day emissions of NOX that may be required under the NOX SIP Call for controlled sources to the EIS using the data elements described in this subpart.

(4) A state may, at its option, include estimates of emissions for additional pollutants (such as hazardous air pollutants) in its emission inventory reports.

(b) Sources. Emissions should be reported from the following sources in all parts of the state, excluding sources located on tribal lands:

(1) Point.

(2) Nonpoint. States may choose to meet the requirements for some of their nonpoint sources by accepting the EPA's estimates for the sources for which the EPA makes calculations. In such instances, states are encouraged to review and update the activity values or other calculational inputs used by the EPA for these sources.

(3) Onroad and Nonroad mobile. (i) Emissions for onroad and nonroad mobile sources must be reported as inputs to the latest EPA-developed mobile emissions models, such as the Motor Vehicle Emissions Simulator (MOVES) for onroad sources or the NMIM for nonroad sources. States using these models may report, at their discretion, emissions values computed from these models in addition to the model inputs.

(ii) In lieu of submitting model inputs for onroad and nonroad mobile sources, California must submit emissions values.

(iii) In lieu of submitting any data, states may accept existing EPA emission estimates.

(4) Emissions for wild and prescribed fires are not required to be reported by states. If states wish to optionally report these sources, they must be reported to the events data category. The events data category is a day-specific accounting of these large-scale but usually short duration emissions. Submissions must include both daily emissions estimates as well as daily acres burned values. In lieu of submitting this information, states may accept the EPA estimates or they may submit inputs (e.g., acres burned, fuel loads) for us to use in the EPA's estimation approach.

(c) Supporting information. You must report the data elements in Tables 2a and 2b in Appendix A of this subpart.We may ask you for other data on a voluntary basis to meet special purposes.

(d) Confidential data. We do not consider the data in Tables 2a and 2b in Appendix A of this subpart confidential, but some states limit release of these types of data.Any data that you submit to EPA under this subpart will be considered in the public domain and cannot be treated as confidential. If Federal and state requirements are inconsistent, consult your EPA Regional Office for a final reconciliation.

[73 FR 76552, Dec. 17, 2008, as amended at 80 FR 8795, Feb. 19, 2015]

§51.20   What are the emission thresholds that separate point and nonpoint sources?

(a) All anthropogenic stationary sources must be included in your inventory as either point or nonpoint sources.

(b) Sources that meet the definition of point source in this subpart must be reported as point sources. All pollutants specified in §51.15(a) must be reported for point sources, not just the pollutant(s) that qualify the source as a point source.

(c) If your state has lower emission reporting thresholds for point sources than paragraph (b) of this section, then you may use these in reporting your emissions to EPA.

(d) All stationary source emissions that are not reported as point sources must be reported as nonpoint sources. Episodic wind-generated particulate matter (PM) emissions from sources that are not major sources may be excluded, for example dust lifted by high winds from natural or tilled soil. Emissions of nonpoint sources should be aggregated to the resolution required by the EIS as described in the current National Emission Inventory (NEI) inventory year plan posted at http://www.epa.gov/ttn/chief/eiinformation.html. In most cases, this is county level and must be separated and identified by source classification code (SCC). Nonpoint source categories or emission events reasonably estimated by the state to represent a de minimis percentage of total county and state emissions of a given pollutant may be omitted.

(1) The reporting of wild and prescribed fires is encouraged but not required and should be done via only the “Events” data category.

(2) Agricultural fires (also referred to as crop residue burning) must be reported to the nonpoint data category.

[73 FR 76552, Dec. 17, 2008, as amended at 80 FR 8795, Feb. 19, 2015]

§51.25   What geographic area must my state's inventory cover?

Because of the regional nature of these pollutants, your state's inventory must be statewide, regardless of any area's attainment status.

§51.30   When does my state report which emissions data to EPA?

All states are required to report two basic types of emission inventories to the EPA: An every-year inventory; and a triennial inventory.

(a) Every-year inventory. See Tables 2a and 2b of Appendix A of this subpart for the specific data elements to report every year.

(1) All states are required to report every year the annual (12-month) emissions data described in §51.15 from Type A (large) point sources, as defined in Table 1 of Appendix A of this subpart. The first every-year cycle inventory will be for the 2009 inventory year and must be submitted to the EPA within 12 months, i.e., by December 31, 2010.

(2) In inventory years that fall under the triennial inventory requirements, the reporting required by the triennial inventory satisfies the every-year reporting requirements of paragraph (a) of this section.

(b) Triennial inventory. See Tables 2a and 2b to Appendix A of subpart A for the specific data elements that must be reported for the triennial inventories.

(1) All states are required to report for every third inventory year the annual (12-month) emissions data as described in §51.15. The first triennial inventory will be for the 2011 inventory and must be submitted to the EPA within 12 months, i.e., by December 31, 2012. Subsequent triennial inventories (2014, 2017, etc.) will be due 12 months after the end of the inventory year, i.e., by December 31 of the following year.

(2) [Reserved]

[80 FR 8796, Feb. 19, 2015]

§51.35   How can my state equalize the emission inventory effort from year to year?

(a) Compiling a triennial inventory means more effort every 3 years. As an option, your state may ease this workload spike by using the following approach:

(1) Each year, collect and report data for all Type A (large) point sources (this is required for all Type A point sources).

(2) Each year, collect data for one-third of your sources that are not Type A point sources. Collect data for a different third of these sources each year so that data has been collected for all of the sources that are not Type A point sources by the end of each 3-year cycle. You must save 3 years of data and then report all emissions from the sources that are not Type A point sources on the triennial inventory due date.

(3) Each year, collect data for one-third of the nonpoint, nonroad mobile, and onroad mobile sources. You must save 3 years of data for each such source and then report all of these data on the triennial inventory due date.

(b) For the sources described in paragraph (a) of this section, your state will have data from 3 successive years at any given time, rather than from the single year in which it is compiled.

(c) If your state chooses the method of inventorying one-third of your sources that are not Type A point sources and triennial inventory nonpoint, nonroad mobile, and onroad mobile sources each year, your state must compile each year of the 3-year period identically. For example, if a process has not changed for a source category or individual plant, your state must use the same emission factors to calculate emissions for each year of the 3-year period. If your state has revised emission factors during the 3 years for a process that has not changed, you must compute previous years' data using the revised factor. If your state uses models to estimate emissions, you must make sure that the model is the same for all 3 years.

[80 FR 8796, Feb. 19, 2015]

§51.40   In what form and format should my state report the data to EPA?

You must report your emission inventory data to us in electronic form. We support specific electronic data reporting formats, and you are required to report your data in a format consistent with these. The term “format” encompasses the definition of one or more specific data fields for each of the data elements listed in Tables 2a and 2b in Appendix A of this subpart; allowed code values for certain data fields; transmittal information; and data table relational structure. Because electronic reporting technology may change, contact the EPA Emission Inventory and Analysis Group (EIAG) for the latest specific formats. You can find information on the current formats at the following Internet address: http://www.epa.gov/ttn/chief/eis/2011nei/xml_data_eis.pdf. You may also call the air emissions contact in your EPA Regional Office or our Info CHIEF help desk at (919) 541-1000 or send email to info.chief@epa.gov.

[80 FR 8796, Feb. 19, 2015]

§51.45   Where should my state report the data?

(a) Your state submits or reports data by providing it directly to EPA.

(b) The latest information on data reporting procedures is available at the following Internet address: http://www.epa.gov/ttn/chief. You may also call our Info CHIEF help desk at (919) 541-1000 or e-mail to info.chief@epa.gov.

§51.50   What definitions apply to this subpart?

Aircraft engine type means a code defining a unique combination of aircraft and engine used as an input parameter for calculating emissions from aircraft.

Annual emissions means actual emissions for a plant, point, or process that are measured or calculated to represent a calendar year.

Control measure means a unique code for the type of control device or operational measure (e.g., wet scrubber, flaring, process change, ban) used to reduce emissions.

Emission calculation method means the code describing how the emissions for a pollutant were calculated, e.g., by stack test, continuous emissions monitor, EPA emission factor, etc.

Emission factor means the ratio relating emissions of a specific pollutant to an activity throughput level.

Emission operating type means the operational status of an emissions unit for the time period for which emissions are being reported, i.e., Routine, Startup, Shutdown, or Upset.

Emission process identifier means a unique code for the process generating the emissions.

Emission type means the type of emissions produced for onroad and nonroad sources or the mode of operation for marine vessels.

Emissions year means the calendar year for which the emissions estimates are reported.

Facility site identifier means the unique code for a plant or facility treated as a point source, containing one or more pollutant-emitting units. The EPA's reporting format allows for state submittals to use either the state's data system identifiers or the EPA's Emission Inventory System identifiers.

Facility site name means the name of the facility.

Lead (Pb) means lead as defined in 40 CFR 50.12. Emissions of Pb which occur either as elemental Pb or as a chemical compound containing Pb should be reported as the mass of the Pb atoms only.

Mobile source means a motor vehicle, nonroad engine or nonroad vehicle, where:

(1) A motor vehicle is any self-propelled vehicle used to carry people or property on a street or highway;

(2) A nonroad engine is an internal combustion engine (including fuel system) that is not used in a motor vehicle or a vehicle used solely for competition, or that is not affected by sections 111 or 202 of the CAA; and

(3) A nonroad vehicle is a vehicle that is run by a nonroad engine and that is not a motor vehicle or a vehicle used solely for competition.

NAICS means North American Industry Classification System code. The NAICS codes are U.S. Department of Commerce's codes for categorizing businesses by products or services and have replaced Standard Industrial Classification codes.

Nitrogen oxides (NOX) means nitrogen oxides (NOX) as defined in 40 CFR 60.2 as all oxides of nitrogen except N2O. Nitrogen oxides should be reported on an equivalent molecular weight basis as nitrogen dioxide (NO2).

Nonpoint sources collectively represent individual sources that have not been inventoried as specific point or mobile sources. These individual sources treated collectively as nonpoint sources are typically too small, numerous, or difficult to inventory using the methods for the other classes of sources.

Particulate matter (PM) is a criteria air pollutant. For the purpose of this subpart, the following definitions apply:

(1) Filterable PM2.5 or Filterable PM10: Particles that are directly emitted by a source as a solid or liquid at stack or release conditions and captured on the filter of a stack test train. Filterable PM2.5 is particulate matter with an aerodynamic diameter equal to or less than 2.5 micrometers. Filterable PM10 is particulate matter with an aerodynamic diameter equal to or less than 10 micrometers.

(2) Condensable PM: Material that is vapor phase at stack conditions, but which condenses and/or reacts upon cooling and dilution in the ambient air to form solid or liquid PM immediately after discharge from the stack. Note that all condensable PM, if present from a source, is typically in the PM2.5 size fraction and, therefore, all of it is a component of both primary PM2.5 and primary PM10.

(3) Primary PM2.5: The sum of filterable PM2.5 and condensable PM.

(4) Primary PM10: The sum of filterable PM10 and condensable PM.

(5) Secondary PM: Particles that form or grow in mass through chemical reactions in the ambient air well after dilution and condensation have occurred. Secondary PM is usually formed at some distance downwind from the source. Secondary PM should not be reported in the emission inventory and is not covered by this subpart.

Percent control approach capture efficiency means the percentage of an exhaust gas stream actually collected for routing to a set of control devices.

Percent control approach effectiveness means the percentage of time or activity throughput that a control approach is operating as designed, including the capture and reduction devices. This percentage accounts for the fact that controls typically are not 100 percent effective because of equipment downtime, upsets and decreases in control efficiencies.

Percent control approach penetration means the percentage of a nonpoint source category activity that is covered by the reported control measures.

Percent control measures reduction efficiency means the net emission reduction efficiency across all emissions control devices. It does not account for capture device efficiencies.

Physical address means the location address (street address or other physical location description), locality name, state, and postal zip code of a facility. This is the physical location where the emissions occur; not the corporate headquarters or a mailing address.

Point source means large, stationary (non-mobile), identifiable sources of emissions that release pollutants into the atmosphere. A point source is a facility that is a major source under 40 CFR part 70 for one or more of the pollutants for which reporting is required by §51.15 (a)(1). This does not include the emissions of hazardous air pollutants, which are not considered in determining whether a source is a point source under this subpart. The minimum point source reporting thresholds are shown in Table 1 of Appendix A.

Pollutant code means a unique code for each reported pollutant assigned by the reporting format specified by the EPA for each inventory year.

Release point apportionment percent means the average percentage(s) of an emissions exhaust stream directed to a given release point.

Release point exit gas flow rate means the numeric value of the flow rate of a stack gas.

Release point exit gas temperature means the numeric value of the temperature of an exit gas stream in degrees Fahrenheit.

Release point exit gas velocity means the numeric value of the velocity of an exit gas stream.

Release point identifier means a unique code for the point where emissions from one or more processes release into the atmosphere.

Release point stack diameter means the inner physical diameter of a stack.

Release point stack height means physical height of a stack above the surrounding terrain.

Release point type code means the code for physical configuration of the release point.

Reporting period type means the code describing the time period covered by the emissions reported, i.e., Annual, 5-month ozone season, summer day, or winter.

Source classification code (SCC) means a process-level code that describes the equipment and/or operation which is emitting pollutants.

State and county FIPS code means the system of unique identifiers in the Federal Information Placement System (FIPS) used to identify states, counties and parishes for the entire United States, Puerto Rico, and Guam.

Throughput means a measurable factor or parameter that relates directly or indirectly to the emissions of an air pollution source during the period for which emissions are reported. Depending on the type of source category, activity information may refer to the amount of fuel combusted, raw material processed, product manufactured, or material handled or processed. It may also refer to population, employment, or number of units. Activity throughput is typically the value that is multiplied against an emission factor to generate an emissions estimate.

Type A source means large point sources with a potential to emit greater than or equal to any of the thresholds listed in Table 1 of Appendix A of this subpart. If a source is a Type A source for any pollutant listed in Table 1, then the emissions for all pollutants required by §51.15 must be reported for that source.

Unit design capacity means a measure of the size of a point source, based on the reported maximum continuous throughput or output capacity of the unit.

Unit identifier means a unique code for the unit that generates emissions, typically a physical piece of equipment or a closely related set of equipment.

VOC means volatile organic compounds. The EPA's regulatory definition of VOC is in 40 CFR 51.100.

[80 FR 8796, Feb. 19, 2015]

Appendix A to Subpart A of Part 51—Tables

Table 1 to Appendix A of Subpart A—Emission Thresholds1 by Pollutant for Treatment as Point Source Under 40 CFR 51.30

PollutantEvery-year (Type A sources)2Triennial
Type B sourcesNAA sources3
(1) SO2≥2500≥100≥100.
(2) VOC≥250≥100O3 (moderate) ≥100.
   O3 (serious)≥50.
   O3 (severe) ≥25.
   O3 (extreme) ≥10.
(3) NOX≥2500≥100≥100.
(4) CO≥2500≥1000O3 (all areas) ≥100.
   CO (all areas) ≥100.
(5) Lead≥0.5 (actual)≥0.5 (actual).
(6) Primary PM10≥250≥100PM10 (moderate) ≥100.
   PM10 (serious) ≥70.
(7) Primary PM2.5≥250≥100≥100.
(8) NH34≥250≥100≥100.

1Thresholds for point source determination shown in tons per year of potential to emit as defined in 40 CFR part 70, with the exception of lead. Reported emissions should be in actual tons emitted for the required time period.

2Type A sources are a subset of the Type B sources and are the larger emitting sources by pollutant.

3NAA = Nonattainment Area. The point source reporting thresholds vary by attainment status for VOC, CO, and PM10.

4NH3 threshold applies only in areas where ammonia emissions are a factor in determining whether a source is a major source, i.e., where ammonia is considered a significant precursor of PM2.5.

Table 2a to Appendix A of Subpart A—Facility Inventory1 Data Elements for Reporting Emissions From Point Sources, Where Required by 40 CFR 51.30

Data elements
(1) Emissions Year.
(2) State and County FIPS Code or Tribal Code.
(3) Facility Site Identifier.
(4) Unit Identifier.
(5) Emission Process Identifier.
(6) Release Point Identifier.
(7) Facility Site Name.
(8) Physical Address (Location Address, Locality Name, State and Postal Code).
(9) Latitude and Longitude at facility level.
(10) Source Classification Code.
(11) Aircraft Engine Type (where applicable).
(12) Facility Site Status and Year.
(13) Release Point Stack Height and Unit of Measure.
(14) Release Point Stack Diameter and Unit of Measure.
(15) Release Point Exit Gas Temperature and Unit of Measure.
(16) Release Point Exit Gas Velocity or Release Point Exit Gas Flow Rate and Unit of Measure.
(17) Release Point Status and Year.
(18) NAICS at facility level.
(19) Unit Design Capacity and Unit of Measure (for some unit types).
(20) Unit Type.
(21) Unit Status and Year.
(22) Release Point Apportionment Percent.
(23) Release Point Type.
(24) Control Measure and Control Pollutant (where applicable).
(25) Percent Control Approach Capture Efficiency (where applicable).
(26) Percent Control Measures Reduction Efficiency (where applicable).
(27) Percent Control Approach Effectiveness (where applicable).

1Facility Inventory data elements need only be reported once to the EIS and then revised if needed. They do not need to be reported for each triennial or every-year emissions inventory.

Table 2b to Appendix A of Subpart A—Data Elements for Reporting Emissions From Point, Nonpoint, Onroad Mobile and Nonroad Mobile Sources, Where Required by 40 CFR 51.30

Data elementsPointNonpointOnroadNonroad
(1) Emissions YearYYYY
(2) FIPS codeYYYY
(3) Shape Identifiers (where applicable)Y
(4) Source Classification CodeYYY
(5) Emission Type (where applicable)YYY
(8) Emission FactorYY
(9) Throughput (Value, Material, Unit of Measure, and Type)YYY
(10) Pollutant CodeYYYY
(11) Annual Emissions and Unit of MeasureYYYY
(12) Reporting Period Type (Annual)YYYY
(13) Emission Operating Type (Routine)Y
(14) Emission Calculation MethodYY
(15) Control Measure and Control Pollutant (where applicable)Y
(16) Percent Control Measures Reduction Efficiency (where applicable)Y
(17) Percent Control Approach Effectiveness (where applicable)Y
(18) Percent Control Approach Penetration (where applicable)Y

[73 FR 76552, Dec. 17, 2008, as amended at 80 FR 8796, Feb. 19, 2015]



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