40 CFR 51.50 - What definitions apply to this subpart?

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§ 51.50 What definitions apply to this subpart?
Activity 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.
Annual emissions means actual emissions for a plant, point, or process that are measured or calculated to represent a calendar year.
Ash content means inert residual portion of a fuel.
Contact name means the complete name of the lead contact person for the organization transmitting the data set, including first name, middle name or initial, and surname.
Contact phone number means the phone number for the contact name.
Control device type means the name of the type of control device (e.g., wet scrubber, flaring, or process change).
Day/wk in operations means days per week that the emitting process operates, averaged over the inventory period.
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. For a boiler, design capacity is based on the reported maximum continuous steam flow, usually in units of million BTU per hour.
Emission factor means the ratio relating emissions of a specific pollutant to an activity or material throughput level.
Emission release point type means the code for physical configuration of the release point.
Emission type means the code describing temporal designation of emissions reported, i.e., Entire Period, Average Weekday, etc.
Exit gas flow rate means the numeric value of the flow rate of a stack gas.
Exit gas temperature means the numeric value of the temperature of an exit gas stream.
Exit gas velocity means the numeric value of the velocity of an exit gas stream.
Facility ID codes means the unique codes for a plant or facility treated as a point source, containing one or more pollutant-emitting units. The EPA's reporting format for a given inventory year may require several facility ID codes to ensure proper matching between databases, e.g., the state's own current and most recent facility ID codes, the EPA-assigned facility ID codes, and the ORIS (Department of Energy) ID code if applicable.
Fall throughput (percent) means the part of the throughput or activity attributable to the three fall months (September, October, November). This expresses part of the annual activity information based on four seasons—typically spring, summer, fall, and winter. It is a percentage of the annual activity (e.g., out of 600 units produced each year, 150 units are produced in the fall which is 25 percent of the annual activity).
FIPS Code. Federal Information Placement System (FIPS) means the system of unique numeric codes the government developed to identify states, counties and parishes for the entire United States, Puerto Rico, and Guam.
Heat content means the amount of thermal heat energy in a solid, liquid, or gaseous fuel, averaged over the period for which emissions are reported. Fuel heat content is typically expressed in units of Btu/lb of fuel, Btu/gal of fuel, joules/kg of fuel, etc.
Hr/day in operations means the hours per day that the emitting process operates averaged over the inventory period.
Inventory end date means the last day of the inventory period.
Inventory start date means the first day of the inventory period.
Inventory year means the year for which emissions estimates are calculated.
Lead (Pb) means lead as defined in 40 CFR 50.12. Lead should be reported as elemental lead and its compounds.
NAICS means North American Industry Classification System code. The NAICS codes are U.S. Department of Commerce's codes for businesses by products or services and have replaced Standard Industrial Classification codes.
Maximum nameplate capacity means a measure of the size of a generator which is put on the unit's nameplate by the manufacturer. The data element is reported in megawatts or kilowatts.
Method accuracy description (MAD) codes means a set of six codes used to define the accuracy of latitude/longitude data for point sources. The six codes and their definitions are:
(1) Coordinate Data Source Code: The code that represents the party responsible for providing the latitude/longitude.
(2) Horizontal Collection Method Code: Method used to determine the latitude/longitude coordinates for a point on the earth.
(3) Horizontal Accuracy Measure: The measure of accuracy (in meters) of the latitude/longitude coordinates.
(4) Horizontal Reference Datum Code: Code that represents the reference datum used to determine the latitude/longitude coordinates.
(5) Reference Point Code: The code that represents the place for which geographic coordinates were established. Code value should be 106 (e.g., point where substance is released).
(6) Source Map Scale Number: The number that represents the proportional distance on the ground for one unit of measure on the map or photo.
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.
Nitrogen oxides (NO X ) 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. 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.
Ozone season means the period from May 1 through September 30 of a year.
Particulate Matter (PM). Particulate matter is a criteria air pollutant. For the purpose of this subpart, the following definitions apply:
(1) Filterable PM 2.5 or Filterable PM 10: 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 PM 2.5: The sum of filterable PM2.5 and condensable PM.
(4) Primary PM 10: 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.
Physical address means the street address of a facility. This is the address of the location where the emissions occur; not, for example, the corporate headquarters.
Point source means large, stationary (nonmobile), 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 the pollutants for which reporting is required, except for 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 in tons per year of pollutant are as follows, as measured in potential to emit:
Pollutant Annual cycle(Type A sources) Three-year cycle
Type B sources 1 NAA sources 2
1 Type A sources are a subset of the Type B sources and are the larger emitting sources by pollutant.
2 NAA = Nonattainment Area. Special point source reporting thresholds apply for certain pollutants by type of nonattainment area. The pollutants by nonattainment area are: Ozone: VOC, NOX, CO; CO: CO; PM10: PM10.
(1) SOX ≥2500 ≥100 ≥100.
(2) VOC ≥250 ≥100 O3 (moderate) ≥ 100.
(3) VOC O3 (serious) ≥ 50.
(4) VOC O3 (severe) ≥ 25.
(5) VOC O3 (extreme) ≥ 10.
(6) NOX ≥ 2500 ≥ 100 ≥ 100.
(7) CO ≥ 2500 ≥1000 O3 (all areas) ≥ 100.
(8) CO CO (all areas) ≥ 100.
(9) Pb ≥ 5 ≥ 5.
(10) PM10 ≥ 250 ≥ 100 PM10 (moderate) ≥ 100.
(11) PM10 PM10 (serious) ≥ 70.
(12) PM2.5 ≥ 250 ≥ 100 ≥ 100.
(13) NH3 ≥ 250 ≥ 100 ≥ 100.
Pollutant code means a unique code for each reported pollutant assigned by the reporting format specified by EPA for each inventory year.
Primary capture and control efficiencies means two values indicating the emissions capture efficiency and the emission reduction efficiency of a primary control device. Capture and control efficiencies are usually expressed as a percentage.
Process ID code means a unique code for the process generating the emissions, typically a description of a process.
Roadway class means a classification system developed by the Federal Highway Administration that defines all public roadways as to type based on land use and physical characteristics of the roadway.
Rule effectiveness (RE) means a rating of how well a regulatory program achieves all possible emissions reductions. This rating reflects the assumption that controls typically are not 100 percent effective because of equipment downtime, upsets, decreases in control efficiencies, and other deficiencies in emission estimates. Rule effectiveness adjusts the control efficiency from what could be realized under ideal conditions to what is actually emitted in practice due to less than ideal conditions.
Rule penetration means the percentage of a nonpoint source category covered by an applicable regulation.
SCC means source classification code, a process-level code that describes the equipment and/or operation which is emitting pollutants.
Site name means the name of the facility.
Spring throughput (percent) means part of the throughput or activity attributable to the three Spring months (March, April, May). See also the definition of Fall throughput.
Stack diameter means the inner physical diameter of a stack.
Stack height means physical height of a stack above the surrounding terrain.
Stack ID code means a unique code for the point where emissions from one or more processes release into the atmosphere.
Sulfur content means the sulfur content of a fuel, usually expressed as percent by weight.
Summer day emissions means an average day's emissions for a typical summer work weekday. The state will select the particular month(s) in summer and the day(s) in the work week to be represented. The selection of conditions should be coordinated with the conditions assumed in the development of reasonable further progress (RFP) plans, rate of progress plans and demonstrations, and/or emissions budgets for transportation conformity, to allow comparability of daily emission estimates.
Summer throughput (percent) means the part of throughput or activity attributable to the three Summer months (June, July, August). See also the definition of Fall throughput.
Total capture and control efficiency (percent) means the net emission reduction efficiency of all emissions collection devices.
Type A source means large point sources with actual annual emissions greater than or equal to any of the emission thresholds listed in Table 1 of Appendix A of this subpart for Type A sources. If a source is a Type A source for any pollutant listed in Table 1, then the emissions for all Table 1 pollutants must be reported for that source.
Unit ID code means a unique code for the unit of generation of emissions, typically a physical piece of or a closely related set of equipment. The EPA's reporting format for a given inventory year may require multiple unit ID codes to ensure proper matching between databases, e.g., the state's own current and most recent unit ID codes, the EPA-assigned unit ID codes if any, and the ORIS (Department of Energy) ID code if applicable.
VMT by SCC means vehicle miles traveled disaggregated to the SCC level, i.e., reflecting combinations of vehicle type and roadway class. Vehicle miles traveled expresses vehicle activity and is used with emission factors. The emission factors are usually expressed in terms of grams per mile of travel. Because VMT does not correlate directly to emissions that occur while the vehicle is not moving, nonmoving emissions are incorporated into the emission factors in EPA's MOBILE Model.
VOC means volatile organic compounds. The EPA's regulatory definition of VOC is in 40 CFR 51.100.
Winter throughput (percent) means the part of throughput or activity attributable to the three winter months (January, February, December of the same year, e.g., winter 2005 is composed of January 2005, February 2005, and December 2005). See also the definition of Fall throughput.
Wk/yr in operation means weeks per year that the emitting process operates.
Work weekday means any day of the week except Saturday or Sunday.
X stack coordinate (longitude) means an object's east-west geographical coordinate.
Y stack coordinate (latitude) means an object's north-south geographical coordinate.

Title 40 published on 2014-07-01

The following are only the Rules published in the Federal Register after the published date of Title 40.

For a complete list of all Rules, Proposed Rules, and Notices view the Rulemaking tab.

  • 2015-02-19; vol. 80 # 33 - Thursday, February 19, 2015
    1. 80 FR 8787 - Revisions to the Air Emissions Reporting Requirements: Revisions to Lead (Pb) Reporting Threshold and Clarifications to Technical Reporting Details
      GPO FDSys XML | Text
      Final rule.
      This final rule is effective on February 19, 2015.
      40 CFR Part 51

This is a list of United States Code sections, Statutes at Large, Public Laws, and Presidential Documents, which provide rulemaking authority for this CFR Part.

This list is taken from the Parallel Table of Authorities and Rules provided by GPO [Government Printing Office].

It is not guaranteed to be accurate or up-to-date, though we do refresh the database weekly. More limitations on accuracy are described at the GPO site.

United States Code
U.S. Code: Title 23 - HIGHWAYS

§ 7401 - Congressional findings and declaration of purpose

§ 7402 - Cooperative activities

§ 7403 - Research, investigation, training, and other activities

§ 7404 - Research relating to fuels and vehicles

§ 7405 - Grants for support of air pollution planning and control programs

§ 7406 - Interstate air quality agencies; program cost limitations

§ 7407 - Air quality control regions

§ 7408 - Air quality criteria and control techniques

§ 7409 - National primary and secondary ambient air quality standards

§ 7410 - State implementation plans for national primary and secondary ambient air quality standards

§ 7411 - Standards of performance for new stationary sources

§ 7412 - Hazardous air pollutants

§ 7413 - Federal enforcement

§ 7414 - Recordkeeping, inspections, monitoring, and entry

§ 7415 - International air pollution

§ 7416 - Retention of State authority

§ 7417 - Advisory committees

§ 7418 - Control of pollution from Federal facilities

§ 7419 - Primary nonferrous smelter orders

§ 7420 - Noncompliance penalty

§ 7421 - Consultation

§ 7422 - Listing of certain unregulated pollutants

§ 7423 - Stack heights

§ 7424 - Assurance of adequacy of State plans

§ 7425 - Measures to prevent economic disruption or unemployment

§ 7426 - Interstate pollution abatement

§ 7427 - Public notification

§ 7428 - State boards

§ 7429 - Solid waste combustion

§ 7430 - Emission factors

§ 7431 - Land use authority

§ 7450 to 7459 - Repealed.

§ 7470 - Congressional declaration of purpose

§ 7471 - Plan requirements

§ 7472 - Initial classifications

§ 7473 - Increments and ceilings

§ 7474 - Area redesignation

§ 7475 - Preconstruction requirements

§ 7476 - Other pollutants

§ 7477 - Enforcement

§ 7478 - Period before plan approval

§ 7479 - Definitions

§ 7491 - Visibility protection for Federal class I areas

§ 7492 - Visibility

§ 7501 - Definitions

§ 7502 - Nonattainment plan provisions in general

§ 7503 - Permit requirements

§ 7504 - Planning procedures

§ 7505 - Environmental Protection Agency grants

§ 7505a - Maintenance plans

§ 7506 - Limitations on certain Federal assistance

§ 7506a - Interstate transport commissions

§ 7507 - New motor vehicle emission standards in nonattainment areas

§ 7508 - Guidance documents

§ 7509 - Sanctions and consequences of failure to attain

§ 7509a - International border areas

§ 7511 - Classifications and attainment dates

§ 7511a - Plan submissions and requirements

§ 7511b - Federal ozone measures

§ 7511c - Control of interstate ozone air pollution

§ 7511d - Enforcement for Severe and Extreme ozone nonattainment areas for failure to attain

§ 7511e - Transitional areas

§ 7511f - NO

§ 7512 - Classification and attainment dates

§ 7512a - Plan submissions and requirements

§ 7513 - Classifications and attainment dates

§ 7513a - Plan provisions and schedules for plan submissions

§ 7513b - Issuance of RACM and BACM guidance

§ 7514 - Plan submission deadlines

§ 7514a - Attainment dates

§ 7515 - General savings clause

§ 7521 - Emission standards for new motor vehicles or new motor vehicle engines

§ 7522 - Prohibited acts

§ 7523 - Actions to restrain violations

§ 7524 - Civil penalties

§ 7525 - Motor vehicle and motor vehicle engine compliance testing and certification

§ 7541 - Compliance by vehicles and engines in actual use

§ 7542 - Information collection

§ 7543 - State standards

§ 7544 - State grants

§ 7545 - Regulation of fuels

§ 7546 - Renewable fuel

§ 7547 - Nonroad engines and vehicles

§ 7548 - Study of particulate emissions from motor vehicles

§ 7549 - High altitude performance adjustments

§ 7550 - Definitions

§ 7551 - Omitted

§ 7552 - Motor vehicle compliance program fees

§ 7553 - Prohibition on production of engines requiring leaded gasoline

§ 7554 - Urban bus standards

§ 7571 - Establishment of standards

§ 7572 - Enforcement of standards

§ 7573 - State standards and controls

§ 7574 - Definitions

§ 7581 - Definitions

§ 7582 - Requirements applicable to clean-fuel vehicles

§ 7583 - Standards for light-duty clean-fuel vehicles

§ 7584 - Administration and enforcement as per California standards

§ 7585 - Standards for heavy-duty clean-fuel vehicles (GVWR above 8,500 up to 26,000 lbs.)

§ 7586 - Centrally fueled fleets

§ 7587 - Vehicle conversions

§ 7588 - Federal agency fleets

§ 7589 - California pilot test program

§ 7590 - General provisions

§ 7601 - Administration

§ 7602 - Definitions

§ 7603 - Emergency powers

§ 7604 - Citizen suits

§ 7605 - Representation in litigation

§ 7606 - Federal procurement

§ 7607 - Administrative proceedings and judicial review

§ 7608 - Mandatory licensing

§ 7609 - Policy review

§ 7610 - Other authority

§ 7611 - Records and audit

§ 7612 - Economic impact analyses

§ 7613 - Repealed.

§ 7614 - Labor standards

§ 7615 - Separability

§ 7616 - Sewage treatment grants

§ 7617 - Economic impact assessment

§ 7618 - Repealed.

§ 7619 - Air quality monitoring

§ 7620 - Standardized air quality modeling

§ 7621 - Employment effects

§ 7622 - Employee protection

§ 7623 - Repealed.

§ 7624 - Cost of vapor recovery equipment

§ 7625 - Vapor recovery for small business marketers of petroleum products

42 U.S. Code § 7450 to 7459 - Repealed.

§ 7625a - Statutory construction

§ 7626 - Authorization of appropriations

§ 7627 - Air pollution from Outer Continental Shelf activities

§ 7628 - Demonstration grant program for local governments

§ 7641 - Noise abatement

§ 7642 - Authorization of appropriations

§ 7651 - Findings and purposes

§ 7651a - Definitions

§ 7651b - Sulfur dioxide allowance program for existing and new units

§ 7651c - Phase I sulfur dioxide requirements

§ 7651d - Phase II sulfur dioxide requirements

§ 7651e - Allowances for States with emissions rates at or below 0.80 lbs/mmBtu

§ 7651f - Nitrogen oxides emission reduction program

§ 7651g - Permits and compliance plans

§ 7651h - Repowered sources

§ 7651i - Election for additional sources

§ 7651j - Excess emissions penalty

§ 7651k - Monitoring, reporting, and recordkeeping requirements

42 U.S. Code § -

§ 7651m - Enforcement

§ 7651n - Clean coal technology regulatory incentives

42 U.S. Code § -

§ 7661 - Definitions

§ 7661a - Permit programs

§ 7661b - Permit applications

§ 7661c - Permit requirements and conditions

§ 7661d - Notification to Administrator and contiguous States

§ 7661e - Other authorities

§ 7661f - Small business stationary source technical and environmental compliance assistance program

§ 7671 - Definitions

§ 7671a - Listing of class I and class II substances

§ 7671b - Monitoring and reporting requirements

§ 7671c - Phase-out of production and consumption of class I substances

§ 7671d - Phase-out of production and consumption of class II substances

§ 7671e - Accelerated schedule

§ 7671f - Exchange authority

§ 7671g - National recycling and emission reduction program

§ 7671h - Servicing of motor vehicle air conditioners

§ 7671i - Nonessential products containing chlorofluorocarbons

§ 7671j - Labeling

§ 7671k - Safe alternatives policy

42 U.S. Code § -

§ 7671m - Relationship to other laws

§ 7671n - Authority of Administrator

42 U.S. Code § -

§ 7671p - International cooperation

§ 7671q - Miscellaneous provisions

Title 40 published on 2014-07-01

The following are ALL rules, proposed rules, and notices (chronologically) published in the Federal Register relating to 40 CFR 51 after this date.

  • 2015-02-19; vol. 80 # 33 - Thursday, February 19, 2015
    1. 80 FR 8787 - Revisions to the Air Emissions Reporting Requirements: Revisions to Lead (Pb) Reporting Threshold and Clarifications to Technical Reporting Details
      GPO FDSys XML | Text
      Final rule.
      This final rule is effective on February 19, 2015.
      40 CFR Part 51