E7-2241. Federal Presumed to Conform Actions Under General Conformity

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Draft notice; request for comment.

SUMMARY:

The Clean Air Act (CAA) section 176(c), 42 U.S.C. 7506(c) and Amendments of 1990 ^[1] require that all Federal actions conform to an applicable State Implementation Plan (SIP). The U.S. Environmental Protection Agency (EPA) has established criteria and procedures for Federal agencies to use in demonstrating conformity with an applicable SIP that can be found at 40 CFR 93.150 et.seq. (“The Rule”).

The Rule allows Federal agencies to develop a list of actions that are presumed to conform to a SIP ^[2] for the criteria pollutants and their precursors that are identified in 40 CFR 93.153(b)(1) and (b)(2) and in the National Ambient Air Quality Standards (NAAQS) under 40 CFR 50.4-50.12.^[3] The criteria pollutants of concern for local airport air quality are ozone (O₃) and its two major precursors (volatile organic compounds (VOC) and nitrogen oxides (NO_X)), carbon monoxide (CO), nitrogen dioxide (NO₂), sulfur dioxide (SO₂),^[4] and particulate matter consisting of small particulates with a diameter less than or equal to 2.5 micrometers (PM_2.5) and larger particulates with a diameter of up to 10 micrometers (PM₁₀).^[5]

According to the Rule,^[6] Federal agencies must meet the criteria for establishing activities that are presumed to conform by either:

(1) Clearly demonstrating that the total of direct and indirect emissions from the type of activities that would be presumed to conform would not:

(i) Cause or contribute to any new violation of any standard in any area;

(ii) Interfere with provisions in the applicable SIP for maintenance of any standard;

(iii) Increase the frequency or severity of any existing violation of any standard in any area; or

(iv) Delay timely attainment of any standard or any required interim emission reductions or other milestones in any area including emission levels specified in the applicable SIP; ^[7] or

(2) Providing documentation that emissions from the types of actions that would be presumed to conform are below the applicable de minimis levels established in 40 CFR 93.153(b)(1) and (b)(2).^[8] This documentation may be based on similar actions that the agency has taken over recent years.^[9] Besides documenting the basis for presumed to conform activities, Federal agencies must fulfill procedural requirements under the Rule relating to publication in the Federal Register, notification to Federal/State/local agencies, opportunity for public comment, and availability of responses to public comments.^[10]

In this Notice, the Federal Aviation Administration (FAA) is proposing categories of actions involving agency approval and financial assistance for airport projects that would be presumed to conform. The benefits of this process include the elimination of unnecessary agency costs associated with evaluating actions with few if any emissions. As a result, the agency will be able to streamline the environmental process by applying more of its resources to actions that have the potential to reach regulated emission levels or adversely impact air quality.

Addressing the need for efficiency and streamlining, the EPA states that the provisions allowing Federal agencies to establish categories of actions that are presumed to conform are “intended to assure that these Rules are not overly burdensome and Federal agencies would not spend undue time assessing actions that have little or no impact on air quality.” ^[11] Furthermore, the EPA states that “Federal actions which are de minimis should not be required by this Rule to make an applicability analysis. A different interpretation could result in an extremely wasteful process which generates vast numbers of useless conformity statements.” ^[12] Consequently, the Rule allows individual Federal agencies to present categories of actions that have been documented to be de minimis and, therefore should be “presumed to conform” to the Rule under 40 CFR 93.153(f).

This Notice contains a summary of documentation and analysis which demonstrates that actions described below will not exceed the applicable de minimis emission levels for nonattainment and maintenance areas, as specified under 40 CFR 93.153(b). In relation to the agency's demonstration of presumed to conform actions, the EPA has defined broad categories of actions in 40 CFR 93.153(c)(2) that are exempt from the Rule because the actions result in no emissions increase or an increase in emissions that is clearly de minimis. In this Notice, the FAA distinguishes various airport-related actions that are exempt under the Rule from those that the FAA proposes to be presumed to conform.

DATES:

Written comments must be received on or before 45 days after the date of publication in the Federal Register.

ADDRESSES:

Address your comments to the individual identified under FOR FURTHER INFORMATION CONTACT.

FOR FURTHER INFORMATION CONTACT:

Dr. Jake A. Plante, Planning and Environmental Division, Federal Aviation Administration, 800 Independence Avenue, APP-400, SW., Room 616, Office of Airports, Washington, DC 20591, [e-mail], phone [phone], fax [phone].

SUPPLEMENTARY INFORMATION:

Comments Invited

The FAA invites comments on the following descriptions and justifications of agency actions that would be presumed to conform. We will accept comments, data, views, or arguments by letter, fax, or e-mail. Send your comments to the person identified under FOR FURTHER INFORMATION CONTACT. Mark your comments, “Federal Presumed to Conform Actions under General Conformity.”

Use the following format when preparing comments:

—Organize your comments issue-by-issue.

—For each issue, state what specific change you are requesting to the proposed policy.

—Include justification, reasons, or data for each change you are requesting.

The FAA will consider all communications received on or before the closing date for comments. We will respond by e-mail or other appropriate means to all comments received. Our responses to public comments will be documented and made available to the public upon request through the person identified under FOR FURTHER INFORMATION CONTACT.

Table of Contents: The major sections of this document are as follows:

I. Background

II. Existing Exemptions

III. Presumed to Conform Project Descriptions and Justifications

IV. How to Apply Presumed to Conform Actions

I. Background

Under the Rule (40 CFR 93.153(g)(h)), the FAA and other agencies are entitled to develop a list of proposed actions that are presumed to conform. The process of establishing presumed to conform classifications is predicated on the concept of conformity. Conformity assures that an activity that is presumed to conform does not cause or contribute to any new violation of the NAAQS or interfere with provisions contained in applicable SIPS.

The administration and enforcement of conformity regulations are delegated by the EPA to the individual States through provisions in each SIP. A SIP is the written plan submitted to the EPA detailing each State's strategy to control air emissions to meet and maintain the NAAQS in geographic areas that are designated as nonattainment areas. The EPA requires each State to devise such a plan for each criteria pollutant causing violations or the EPA will impose a Federal implementation plan (“FIP”) for the State. When a nonattainment area achieves compliance with the NAAQS, it becomes a maintenance area for at least 10 years with ongoing State responsibility to ensure continued attainment.^[13]

General conformity. General conformity refers to the process of demonstrating that a general Federal action conforms to the applicable SIP. A general Federal action is defined more by what it is not, rather than by what it is. A general Federal action is any Federal action that is not a Federal “transportation” action and consequently not subject to the conformity requirements established for Federal highway or transit actions, referred to as “transportation conformity.” A Federal transportation action is an action related to transportation plans, programs, and projects that are developed, funded, or approved under Title 23 United States Code (U.S.C.) or the Federal Transit Act (FTA).^[14] Since FAA actions do not meet the definition of a transportation action, they are general actions by default and thus subject to the General Conformity Rule.

The FAA and other Federal agencies subject to general conformity must make a determination that the Federal action conforms to the SIP's purpose to meet and maintain the NAAQS before the action is taken. If the proposed actions are not specifically exempt or classified as presumed to conform, it is necessary to conduct an applicability analysis to determine if emissions are likely to equal or exceed the established screening criteria emission rates known as the de minimis thresholds. A general conformity determination is required for each pollutant identified as nonattainment or maintenance when the total of direct and indirect emissions caused by a Federal action equals or exceeds any of the applicable de minimis thresholds.^[15]

FAA airport development actions subject to general conformity. The FAA is responsible for deciding whether its actions involving an airport located in a nonattainment or maintenance area require a general conformity evaluation.^[16] FAA actions that require a conformity evaluation include unconditional approval of any or all parts of an airport layout plan (ALP), final Airport Improvement Program (AIP) grant approvals, and approvals for use of Passenger Facility Charges (PFCs). Other FAA actions that may require a conformity evaluation include proposed actions for which an environmental assessment (EA) or environmental impact statement (EIS) is prepared under the requirements of the National Environmental Policy Act.

Notification requirements for establishing a list of presumed to conform actions. Under procedures prescribed in the Rule, the FAA must notify the appropriate EPA regional offices, State and local air quality agencies, and Metropolitan Planning Organizations (MPO).^[17] In addition, the FAA must publish the proposed list in the Federal Register, allowing a minimum of 30 days for public comment.^[18] The FAA is required to document its response to all comments received and to make these comments and responses available to the public upon request.^[19] Finally, the FAA must publish its final list of presumed to conform actions in the Federal Register to complete the process.^[20]

II. Existing Exemptions

For the FAA to provide the proper context and baseline for identifying and proposing a list of presumed to conform Federal actions, it is important to consider the extent to which FAA airport-related actions and activities may qualify for exemption from general conformity requirements. The EPA has defined broad categories of exempt actions under 40 CFR 93.153(c)(2) that result in no emissions increase or increases in emissions that are clearly de minimis. These actions are not subject to further analysis for applicability, conformity, or regional significance under the Rule.

As part of this Federal Register Notice, the FAA has interpreted how the exemptions in the Rule apply to FAA actions associated with airport facilities and aviation planning. The following discussion addresses the most relevant examples of these exemptions regarding FAA actions for airport development.

(1) Rulemaking and Policy Development [40 CFR 93.153(c)(2)(iii)]

The FAA develops rules and policies to address issues of safety, aviation noise abatement, and systematic improvements to efficiency. This includes issuance of airport policy and planning documents for the National Plan of Integrated Airport Systems (NPIAS), the Airport Capital Improvement Program (ACIP), and Advisory Circulars on planning, design, and development programs. These documents provide administrative and technical guidance to the airport community and the public and are not intended for direct implementation. The actual process of rulemaking or policy development is typically administrative in nature and does not cause an increase in air emissions.

(2) Routine Maintenance and Repair Activities [40 CFR 93.153(c)(2)(iv)]

In conformance with FAA standards and regulations, the airport sponsor must maintain airport facilities and the airfield in a manner that ensures the safe operation of the airport. These activities constitute Federal actions when Federal funding from the FAA is involved. Airport maintenance, repair, removal, replacement, and installation work that matches the characteristics, size, and function of a facility as it existed before the replacement or repair activity typically qualifies as routine maintenance and repair for purposes of general conformity. Such activity does not increase the capacity of the airport or change the operational environment of the airport.

The FAA does not consider major runway reconstruction to qualify as exempt under the Rule if the reconstruction results in a runway that is hardened, lengthened, or widened to support a larger class of aircraft. Proposed funding for such a project would require analysis of emission levels to determine the applicability of general conformity requirements.

Routine maintenance for existing runways, taxiways, aprons, ramps, fillets, and airport roadways includes in-kind resurfacing,^[21] re-marking of existing runways, taxiways, apron areas, etc., and runway grooving and rubber removal projects. Other areas of routine replacement, maintenance, and repair work that may be considered exempt from the Rule include:

• Existing signage.
• Existing lighting systems.
• Existing pavement markings.
• Wind or landing direction indicators.
• Existing airport security access control.
• Existing buildings and structures.
• Existing heating, ventilation, and air conditioning (HVAC) systems.
• Existing infrastructure such as sanitary sewer or electrical systems.
• General landscaping, erosion control, and grading.

(3) The Routine, Recurring Transportation of Materiel and Personnel [40 CFR 93.153(c)(2)(vii)]

The transport of materiel and personnel both within airport environs and to facilities affiliated with the routine operation of airports may be considered exempt under the Rule.

(4) Routine Movement of Mobile Assets, Such As * * * Aircraft * * * for Repair or Overhaul [40 CFR 93.153(c)(2)(viii)]

The movement of aircraft to/from airports with maintenance and test facilities for repair and overhaul may be considered exempt from the Rule.

(5) Planning, Studies, and Provisions of Technical Assistance [40 CFR 93.153(c)(2)(xii)]

Planning and information-related actions do not represent implementation of operational changes at the airport and therefore do not result in emission increases. Consequently, actions such as those listed below may be considered exempt from the Rule:

• FAA funding and acceptance of Master Plans and Updates
• FAA funding of System Planning Studies
• FAA acceptance of noise exposure maps and approval of noise compatibility programs pursuant to 49 U.S.C. 47501 et seq., as implemented by 14 CFR Part 150
• FAA approval of noise and access restrictions on operations by Stage 3 aircraft under 49 U.S.C. 47524, as implemented by 14 CFR Part 161

(6) Routine Operation of Facilities, Mobile Assets and Equipment [40 CFR 93.153(c)(2)(xiii)]

Normal day-to-day activities that occur at airports, such as vehicle movements, building operations, and aircraft movements that do not increase the capacity of the airport or change the operational environment of the airport may be considered exempt from the Rule.

(7) Transfers of Ownership, Interests, and Titles in Land, Facilities, and Real and Personal Properties, Regardless of the Form or Method of the Transfer [40 CFR 93.153(c)(2)(xiv)] and

(8) Actions (or Portions Thereof) Associated With Transfers of Land, Facilities, Title, and Real Properties Through an Enforceable Contract or Lease Agreement Where the Delivery of the Deed Is Required To Occur Promptly After a Specific, Reasonable Condition Is Met, Such as Promptly After the Land Is Certified as Meeting the Requirements of Comprehensive Environmental Response, Compensation and Liability Act (CERCLA), and Where the Federal Agency Does Not Retain Continuing Authority To Control Emissions Associated With the Lands, Facilities, Title, or Real Properties [40 CFR 93.153(c)(2)(xix)]

Actions by the FAA to transfer or acquire land or equipment do not increase the capacity of the airport or change the operational environment affecting air emissions. Such actions include funding or approving transfers, acquisitions, or releases by airport sponsors, ^[22] or preparing and executing related contracts or written agreements. Related actions that may be considered exempt from the Rule are:

• Facilities and equipment purchases.
• Land acquisition and relocation assistance.
• Land releases for which there is no reasonable expectation of a change in land use.
• Avigation easement acquisition.
• Acquisition of an existing privately owned airport involving only change of ownership.

(9) Alterations and Additions of Existing Structures as Specifically Required By New or Existing Applicable Environmental Legislation or Environmental Regulations (e.g., Hush Houses for Aircraft Engines* * *) [40 CFR 93.153(d)(4)]

Actions that are initiated in response to specific environmental laws and regulations (e.g., energy efficiency, noise abatement structures and equipment) may be considered exempt from the Rule. These actions include:

• Equipment purchases.
• Protective noise barriers.
• Required noise mitigation actions including the installation and operation of hush houses for aircraft and engine maintenance.

(10) Federal Actions Which Are Part of a Continuing Response to an Emergency or Disaster [40 CFR 93.153(d)(2) and (e)]

Actions in response to emergencies, natural disasters, etc., that involve overriding concerns for public health and welfare, national security interests, or foreign policy commitments may be exempt from general conformity requirements for six months and possibly longer if justified in writing by the agency.^[23]

III. Presumed to Conform Project Descriptions and Justifications

The FAA began the process of developing and documenting presumed to conform actions with a detailed environmental survey of airport projects. The survey was conducted by all FAA regional offices, which identified approved airport projects over a recent two-year period that received a categorical exclusion (CATEX) or Finding of No Significant Impact (FONSI).^[24] This information was requested only for airports included in areas designated as nonattainment or maintenance by the EPA. Information compiled from these surveys described about 600 completed projects at over 100 airports.

The survey information was processed by assigning each airport planning and development project into one of two categories: (1) Projects that are exempt from the requirements of the Rule as defined by 40 CFR 93.153(e); or (2) projects that require an applicability analysis before being defined as de minimis (i.e., presumed to conform), according to 40 CFR 93.153(c)(1). Specific information on the application of these two project categories is presented in Section II and Section III of this document, respectively.

In the analysis of the survey results, any airport project that exceeded de minimis levels even once was considered ineligible for the presumed to conform list. Follow-up communications with airports and FAA regional representatives helped to clarify terminology and confirm the reliability of the presumptions. In addition, the FAA performed detailed worst-case analyses where practicable in areas where project size and implementation could conceivably result in the exceedance of de minimis levels.

The airport project survey data and other agency experience in implementing similar actions taken over recent years provide the fundamental basis for all of the presumed to conform classifications. The FAA conducted additional quantitative analyses for specific project areas, as practicable. These analyses are summarized in Section III, and include the following: Pavement markings; terminal upgrades; commercial vehicle staging areas; non-runway paving; heating, ventilation, and air conditioning (HVAC) systems; and low-emission technology and alternative fuel vehicles.

Based on the survey of airport projects, the additional evaluations, and quantitative analyses, only those project categories that were proven to be reliably and consistently de minimis were classified as presumed to conform. In general, FAA presumed to conform actions involve maintenance, navigation, construction, safety, security activities, and new technology and vehicle systems that do not modify or increase airport capacity or change the operational environment of the airport in such a way as to increase air emissions above de minimis thresholds.

Presented below are the airport project descriptions and justifications for FAA actions that are presumed to conform. There are fifteen project categories, which are discussed in the following order:

1. Pavement Markings.

2. Pavement Monitoring Systems.

3. Non-Runway Pavement Work.

4. Aircraft Gate Areas on Airside.

5. Lighting Systems.

6. Terminal and Concourse Upgrades.

7. New HVAC Systems, Upgrades, and Expansions.

8. Airport Security.

9. Airport Safety.

10. Airport Maintenance Facilities.

11. Airport Signage.

12. Commercial Vehicle Staging Areas.

13. Low-Emission Technology and Alternative Fuel Vehicles.

14. Air Traffic Control Activities and Adopting Approach, Departure and Enroute Procedures for Air Operations.

15. Routine Installation and Operation of Aviation Navigation Aids.

1. Pavement Markings

Airport sponsors apply paint on paved surfaces, such as runways, taxiways, apron areas, cargo areas, and parking lots to ensure the safe operation of aircraft during approach and landing and to provide safe direction for surface vehicles. Most pavement marking projects are considered routine maintenance activities, qualifying as exempt from the Rule (see Section II, number 2 of this Notice). These actions are designed to restore and improve painted surfaces that have deteriorated due to time, use, and weather.

Federal actions that alter airport use through new pavement markings are not routine maintenance but are presumed to conform if such actions do not increase airport capacity or introduce a larger class of aircraft at the airport. For example, new runway markings for improved flight procedures from visual flight rules (VFR) to instrument flight rules (IFR) are presumed to conform if normal traffic flow is maintained.

Pollutant emissions due to the paint application process are primarily composed of VOC from the paint, and NO_X emitted from the trucks and application compressors required to prepare the surface and apply the paint. Emissions of both VOC and NO_X are considered precursors to the development of ozone in the atmosphere. Therefore, emissions from the application of painted pavement markings pertain most importantly to ozone nonattainment and maintenance areas.

A worst-case calculation of emissions was performed based on equipment and types of paint required to mark a Category III 13,000-foot runway with an instrument lighting system (ILS) to FAA specifications. The calculation of emissions included the removal of existing markings using water pressure through a compressor mounted on a diesel truck, a pavement sweeper truck to remove debris, the application of the paint using an air compressor mounted on a diesel truck, and a small hand sprayer for detailed markings, such as squared corners. A total of 2,492 gallons of paint (a combination of white, yellow, and black) were applied to the representative runway at a rate of 115 square feet per gallon of paint. The trucks transporting the paint and compressors were assumed to be similar to a single axle, Class 7 diesel pickup truck.^[25] The sweeper was assumed to be a regenerative diesel air power model, using a chassis engine and an auxiliary engine to power the brushes. Manufacturers' Material Safety Data Sheets were referenced for the VOC emissions factors for the three colors of latex paint. Emissions factors for the criteria and precursor pollutants were obtained from the EPA Nonroad Engine and Vehicle Emission Study-Report.^[26] Load factors and horsepower ratings were obtained from the EPA Nonroad Engine and Vehicle Emission Study-Report and Median Life, Annual Activity, and Load Factor Values for Nonroad Engine Emissions Modeling.^[27]

The maximum volume of paint that could be applied without equaling or exceeding the de minimis thresholds for any nonattainment and maintenance classification was calculated.^[28] For instance, an airport located within an extreme nonattainment area for ozone is limited to net project emissions of 10 tons of VOC per year. This translates into an annual application of 21,890 gallons of paint, which also causes 0.21 tons ^[29] of NO_X emissions. For example, this volume of paint would mark eight Category III 13,000-foot ILS runways. A volume of paint on the order of one million gallons is required to cause emissions of NO_X to equal 10 tons per year. Likewise, a volume of paint on the order of five million to 176 million gallons is required in order to be sufficient to exceed the de minimis thresholds for CO, SO₂, or PM₁₀. Therefore, VOCs are the limiting pollutant ^[30] for the application of paint at airports and emissions of NO_X, CO, SO₂, and PM₁₀ are considerably less. Table III-1 provides the gallon application limits, which include the use of construction equipment for pavement markings in nonattainment and maintenance areas.

2. Pavement Monitoring Systems

Airports have the option of installing a pavement monitoring system to indicate when the durability and strength of the pavement needs to be reinforced. These systems are implemented for safety reasons to ensure that an airport's runway, taxiway, and apron network are sufficiently able to support the weight of aircraft. Minor construction work is required for the installation of the monitoring system. Assuming the installation requires the use of a pickup truck, a utility truck, an excavator, an asphalt paver, a compactor, and a small generator, construction would have to proceed continuously (eight hours per day, 20 days per month) for more than a year (1.1 years) in order to produce emissions near the level of 10 tons of NO_X. For the remaining criteria pollutants and precursors, construction on the order of several years would be required to approach the de minimis thresholds. Pavement monitoring systems are installed in less than a week; therefore, project construction emissions are well below de minimis and presumed to conform.

3. Non-Runway Pavement Work

Airfield pavement must be constructed to withstand the weight of aircraft and to produce a firm, stable, smooth, year-round, all-weather surface. The pavement must be of such quality and thickness that it will not fail under the weight of aircraft and it must possess sufficient inherent stability to withstand, without damage, the abrasive action of aircraft traffic and adverse weather conditions.^[31] These pavement specifications apply to non-runway areas of the airfield where aircraft operate, including taxiways, apron areas, and gate areas. The specific pavement requirements are satisfied by applying rigid pavement consisting of layers of crushed stone bound and pressed into a smooth surface.

Airfield construction projects considered to be presumed to conform are limited to areas of the airfield intended to accommodate aircraft for purposes of loading or unloading passengers or cargo, refueling, or aircraft parking, and are generally referred to as apron areas. These types of airfield projects do not include projects intended to increase airport capacity or those that are otherwise defined as routine maintenance for existing apron areas.

Pollutant emissions due to airfield construction are solely from the use of construction equipment and are primarily comprised of NO_X, a precursor to ozone development, and CO resulting from the trucks operated to haul the large amounts of stone and gravel that must be used to form the support layers for the paving material.

The evaluation of emissions from airfield paving was based on a representative project in the FAA Eastern Region. The project required equipment and materials to construct approximately 600,000 square feet of airfield and concrete shoulder area with an assumed surface design life of 20 years.^[32] The conservative calculation of emissions included the preparation of the site allowing for a four-inch geotextile layer of subgrade soil, a four-inch frost protection layer of crushed stone, a four-inch sub base layer of finely crushed stone, an eight-inch base layer of gravel mixed with a stabilizer such as cement,^[33] and the application of a six-inch layer of Portland cement concrete.^[34] This type of construction design allows for a total pavement thickness of 26 inches; the minimum total pavement thickness for the accommodation of jet aircraft weighing 100,000 pounds or more is 20 inches.^[35] Also included in the construction emissions inventory is the installation of a drainage system.

Emissions factors for construction equipment were obtained from the EPA's 1991 Nonroad Engine and Vehicle Emission Study—Report.^[36] Load factors and horsepower ratings for the construction equipment were obtained from the EPA's 1991 Nonroad Engine and Vehicle Emission Study—Report and the EPA's 1997 Median Life, Annual Activity, and Load Factor Values for Nonroad Engine Emissions Modeling.^[37]

The maximum allowable square footage of airfield construction was calculated for each nonattainment and maintenance category. The analysis showed that NO_X was the limiting pollutant for airfield paving projects and that emissions of VOC, CO, SO₂, and PM₁₀ are considerably less in comparison with NO_X.

Table III-1 provides the area limits for non-runway airfield construction in nonattainment and maintenance areas. For instance, an airport located within an area designed as extreme nonattainment for ozone, which limits net project emissions to the rate of 10 tons per year of NO_X, is limited to constructing 219,368 square feet (5.04 acres) of apron area, which also causes 0.93 tons of VOC emissions. As a reference, four acres is generally sufficient to provide remote or “hardstand” (non-gate) parking for three narrow-body aircraft. Construction of an airfield/apron area on the order of 2.38 million square feet (54.7 acres) causes emissions of VOC up to 10 tons per project, creating emissions of NO_X of approximately 109 tons. New airfield construction on the order of 150 to 600 acres would be required to exceed the de minimis thresholds for CO, SO₂ and PM₁₀. Generally speaking, emissions of NO_X are on the order of three times the emissions of CO for these types of projects and are more than 10 times the emissions of the remaining criteria pollutants.

4. Aircraft Gate Areas on Airside

Aircraft gate areas refer to the area outside of the terminals and concourses where jetways are used to link parked aircraft to the terminal building. Federal actions to improve aircraft gate areas can be part of airport modernization efforts involving new airline tenants or the introduction of newer and more efficient technology. Aircraft gate areas involve a wide range of activities from aircraft loading and unloading of passengers and cargo to the servicing of aircraft by lavatory, food supply, and maintenance vehicles.

Upgrades to the aircraft gate area are often needed to accommodate changing flight schedules and daily activity. The addition or modification of jetways to existing terminal buildings is typically done to adjust to changes in air travel demand and airline requirements. Such projects are intended to improve passenger terminal service by reducing passenger queuing and waiting times. Actions to approve or fund the upgrading of aircraft gate areas are presumed to conform provided such actions do not increase aircraft operations or introduce a larger class of aircraft at the airport.

5. Lighting Systems

Airport sponsors may need to install new lighting systems to maintain proper illumination of roadways, taxiways, runways, and parking areas. The data from the FAA surveys indicated that airport upgrading and installing of new lighting systems is done on an as-needed basis.

Minor mechanical work is required for the installation effort, followed by electrical work that does not require large off-road construction equipment. Assuming the installation requires the use of a pickup truck, a utility truck, an excavator, and a small generator, the construction will have to proceed continuously (eight hours a day, 20 days a month) for more than 17 months (1.4 years) in order to produce emissions near the level of 10 tons of NO_X. For the remaining criteria pollutants and precursors, construction on the order of several years would be required to approach the de minimis thresholds. Runway and other lighting systems can be installed in less than two weeks; therefore, project construction emissions are well below de minimis and presumed to conform.

6. Terminal and Concourse Upgrades

The opportunity to expand or upgrade terminals and/or concourses for the purpose of improving passenger convenience typically involves increasing the interior terminal space in areas such as hold rooms, concessions, restrooms, and gate areas. Qualifying projects in this category do not have the effect of attracting more passengers. Nor do they have the effect of increasing the airport's ability to accommodate additional numbers or types of aircraft or to increase passenger loading on scheduled flights. Major terminal and/or concourse expansion projects that are designed to increase passenger usage or to support increased airfield capacity through new aircraft gates, runways, taxiways, etc. require an inventory of direct and indirect emissions to determine the applicability of general conformity.

Construction vehicles and equipment are the only source of emissions when expanding or upgrading terminals. A conservative approach to quantifying construction emissions was used to determine the appropriate limits for this type of activity. The emission limits are presented in Table III-1 under “Terminal Upgrades” according to the de minimis thresholds.

A proposed terminal expansion project located in the FAA's Southern Region was used as the representative project. The terminal was proposed to have an additional footprint of 381,000 square feet. This proposed project was purposely selected to provide a conservative estimate of construction emissions normally released from this type airport improvement activity, even though this presumed to conform activity is limited to non-capacity enhancing projects. Emissions were quantified in this case from construction activities, including soil cement preparation, subgrade preparation, light and heavy demolition, cement base treatment, installation of the grade aggregate base, construction of the terminal, light and heavy utility work, and light and heavy earthwork. In addition, the proposed terminal expansion was assumed to occur within the same calendar year instead of the proposed schedule of seven years.

Construction emissions were calculated using prescribed EPA methodology incorporating the projected construction activity level, the number of construction vehicles and equipment, and industry-wide utilization rates. Emission factors for construction vehicles and equipment were taken from EPA databases for nonroad vehicles and engines,^[38] and their updates.^[39]

A proposed terminal/concourse expansion project is presumed to conform up to the square foot additions (footprint) of the project as determined by the most limiting pollutant (see Table III-1). The prescribed build-out limits per calendar year apply to all components of the terminal/concourse upgrade project according to the air quality status of the area in which the project is located.

7. New HVAC Systems, Upgrades, and Expansions

Upgrading and expanding heating, ventilation, and air conditioning (HVAC) systems are presumed to conform because any emission increases associated with improvements to airport heating and cooling systems are generally minor and well below de minimis thresholds.

Heating for airport terminal buildings is typically provided through a boiler system.^[40] Boilers may be fueled by natural gas, coal (bituminous, sub-bituminous, or anthracite), No. 5 and No. 6 fuel oil (residual), No. 2 fuel oil (diesel), culm fuel, and liquefied petroleum gas (propane or butane). Pollutant emissions due to the operation of boilers vary with the fuel used. The emission factors for the various fuels are presented in Table III-2 below.

A new, upgraded, or expanded boiler system involves the installation of new equipment to replace or expand the capacity of existing boiler systems. Boilers can be very large and are sometimes delivered on flatbed semi-tractor trailer trucks and set in place by a crane. Table III-3 presents the construction emissions, primarily NO_X and CO, associated with the installation of a large boiler as described.

Airport terminals consume energy for heat at a higher rate than most public buildings. The reasons for this include the open areas surrounding many airports, heat loss from the movement of people and baggage in and out of buildings, and the usual 24-hour operation of facilities. The consumption of energy to generate heat is also dependent upon the design of the terminal building. For instance, many airport terminals are designed with exterior glass walls or incorporate design, art, and architectural treatments that reflect local customs and community history.^[41] The many variations of airport terminal design, including geographical location, make it impractical to identify the “typical terminal building” for purposes of determining total emissions. Therefore, the presumption of conformity could not be based on the characteristics of the building, but rather on the volume of fuel consumed.

As discussed, emissions resulting from the operation of boilers depend on the type of fuel powering the boiler system. Emissions from the use of propane, butane, and natural gas are of concern in ozone nonattainment and maintenance areas since the primary pollutant from combustion of these fuels is NO_X, a precursor to ozone formation. Hydrocarbons (HCs) are another precursor to ozone but they are relatively low for these fuel types in comparison to NO_X emissions. The primary pollutant from the combustion of fuel oil (No. 2 diesel, and No. 5 and No. 6 residual) is SO₂, while particulate matter is the primary pollutant from the combustion of coal, including culm fuel). Therefore, NO_X, SO₂, and PM₁₀ are the most likely limiting pollutants for the operation of boiler systems at airports.

Table III-4 below presents maximum annual fuel throughput for heating systems and boilers by fuel type at levels that do not equal or exceed the de minimis thresholds. The FAA Emissions and Dispersion Modeling System (EDMS) was used to perform the calculations. EDMS emission factors are conservatively based on EPA's AP-42 emissions quantification methodology.^[42]

The analysis shows, for example, that an airport located in a severe nonattainment area for ozone, with a de minimis NO_X threshold of 25 tons per year, could operate new or improved boilers using up to 5.05 million cubic meters of natural gas annually, which is sufficient to heat a building of approximately 210,000 square feet.^[43] NO_X emissions in a severe ozone nonattainment area would be limited to 3,434 kiloliters (kl) of No. 6 fuel oil (residual), 7,816 kl of No. 2 fuel oil (diesel), 9,855 kl of propane, 1,374 metric tons of bituminous coal, or 2,519 metric tons of anthracite coal on an annual basis.

The installation, upgrade, or expansion of an airport HVAC system that requires a permit under new source review (NSR) or prevention of significant deterioration programs is exempt from a general conformity determination.^[44] The inclusion of airport boiler installations/modifications as a presumed to conform activity does not affect existing or future requirements of Federal, State or local air quality operating permit programs. Proper compliance with all applicable environmental regulations must be maintained.

8. Airport Security

Based on collected project information and additional agency experience with airport security actions following the events of September 11, 2001, the FAA has determined that dedicated security-related airport projects qualify as presumed to conform actions, including modification of existing terminals with luggage and passenger scanning devices, addition of camera surveillance, bolstering of airport security fencing, and reinforcement of airport access control. In most cases, the installation of security equipment and upgraded operations in existing facilities will not result in the generation of air emissions. If the construction and installation of some dedicated security projects do cause emissions, these emissions will be minor and well below the de minimis thresholds.

Security requirements also may dictate that parking spaces close to terminal buildings be eliminated.^[45] As a result, FAA actions associated with the expansion of parking facilities to compensate for lost close-in parking are presumed to conform provided these actions are limited to a one-for-one replacement of parking capacity. Generally, the relocation of parking spaces away from the terminal building will reduce vehicle miles traveled (VMT) on airport property, resulting in an emissions decrease.

It is important to note that this category of presumed to conform actions is separate from exempt Federal actions under the Rule that are part of a continuing response to an emergency or disaster.^[46] Agency use of the emergency exemption is limited in time and must involve overriding concerns for public health and welfare, national security interests, and foreign policy commitments.^[47]

9. Airport Safety

Airport projects relating to airport safety include actions specific to the Runway Safety Area (RSA). FAA regulations specify the requirements for a RSA, which is defined as the surface area that surrounds and extends beyond the runway ends that is required for reducing the risk of damage to airplanes in the event of an undershoot, overshoot, or excursion from the runway.^[48] RSA improvements are presumed to conform unless a new road or the relocation of a road is required.

In addition to a safe airfield, airport projects to build, expand, replace, upgrade, or equip a required Aircraft Rescue and Firefighting Facility (ARFF) are presumed to conform. These facilities are relatively small airport projects and must be provided by the airport to ensure airport and passenger safety. Airports must meet ARFF requirements as specified under 14 CFR 139.317, and are responsible for upgrading an ARFF if there is an increase in the average daily departures or the length of an air carrier aircraft.^[49]

10. Airport Maintenance Facilities

Airport maintenance facilities house the equipment necessary to run, service, and maintain the airport environs. These facilities can include vehicle service centers, fueling stations, and storage areas for snow removal and maintenance equipment. FAA actions associated with upgrading airport-owned maintenance facilities are presumed to conform based on the fact that these facilities typically require only minor construction. However, the installation or upgrading of aircraft maintenance facilities (typically owned by an airline or charter company) that are used to paint or maintain aircraft at an airport are not considered presumed to conform because aircraft maintenance facilities may cause an increase in flights to meet maintenance schedules.

11. Airport Signage

Airport sponsors place signs throughout the airport property to direct passengers, employees, and vendors to terminals, parking lots, rental car areas, maintenance areas, etc. In addition, airports provide a network of signs to direct aircraft and vehicles on the airfield. Airport signage is often electrified for illumination at night and for other times of limited visibility. In general, airport signage installation can be completed in a matter of days or weeks. It would require more than a year of continuous installation to exceed the 25-ton threshold for NO_X. Therefore, airport signage installation projects are presumed to conformed.

12. Commercial Vehicle Staging Areas

Commercial vehicle staging areas at airports serve as temporary holding areas for taxicabs, limousines, and other commercial vehicles. Such areas reduce the need to idle at the terminal curb front and help to decongest the terminal roadways. Airports that employ commercial vehicle staging areas may enforce specific idling restrictions or engine-off mandates to further reduce air quality impacts. Generally, the use of commercial vehicle staging areas is an emissions reduction strategy because the alternative inherently creates more emissions from increased traffic and congestion at the terminal.

A Federal action to develop a commercial vehicle staging area for purposes of relieving airport traffic congestion is presumed to conform based on the criteria provided in Table III-1 for a “Commercial Vehicle Staging Area.” Providing a commercial vehicle staging area does not cause an increase in the volume of vehicles on regional roadways and impacts air quality only through the use of construction equipment to pave the staging area. Construction emissions are primarily comprised of NO_X and CO.

The quantity of emissions associated with the construction of an asphalt taxicab staging area was based on a construction design for a regional asphalt roadway. The calculation of emissions included activities such as excavation, preparation of the subgrade, adding a base layer of stone, fine grading, and paving. The paving process included the application of a tack coat, wearing course, and the final seal coat. The type and use of construction equipment was determined based on information obtained from the R.S. Means' Means Building Construction Cost Data, and the State of Ohio Department of Transportation's Manual of Procedures for Flexible Pavement Construction and Pavement Design and Rehabilitation Manual. Rated horsepower and load factors for each construction unit was obtained from the EPA's Nonroad Engine and Vehicle Emission Study-Report and Median Life, Annual Activity, and Load Factor Values for Nonroad Engine Emissions Modeling, and the Caterpillar Performance Handbook. Emission factors were obtained from the EPA's Nonroad Engine and Vehicle Emission Study-Report.

The acreage that could be paved without equaling or exceeding the de minimis thresholds for each applicable nonattainment or maintenance category was calculated and summarized in Table III-1. For instance, an airport located within an area designated as severe nonattainment for ozone, which limits net project emissions to an annual rate of 25 tons of NO_X, is limited to a commercial vehicle staging area of about 13 acres, or 561,584 square feet, which results in 2.35 tons of VOC emissions. Paving of approximately 137 acres is required to cause emissions of VOC of nearly 25 tons, as established for a severe nonattainment area for ozone. In order to approach the 100 ton de minimis thresholds for other criteria pollutants, paving areas of approximately 140 acres would be required for CO, 556 acres for SO₂, and more than 595 acres for PM₁₀. Therefore, NO_X is the limiting pollutant for paving projects at airports and emissions of VOC, CO, SO₂, and PM₁₀ are considerably less in comparison to NO_X.

13. Low-Emission Technology and Alternative Fuel Vehicles

A growing number of airports are interested in new technology and vehicle systems to reduce stationary and mobile emissions. Based on agency and airport low-emission programs over the past several years, which provide extensive data and documentation to verify the emission reduction benefits of new low-emission technology, these activities are presumed to conform.

Activities that are presumed to conform include the replacement, substitution, or conversion of conventional fuel vehicles (gasoline, diesel) to vehicles using alternative or clean conventional fuel technology. Qualified activities also encompass airport low-emission infrastructure improvements and the use of refueling or recharging stations needed to service airport low-emission vehicles.

All low-emission activities funded through the FAA Voluntary Airport Low Emission Program (VALE) or that are required as part of environmental mitigation are presumed to conform.^[50] The VALE program requires that vehicles purchased under the program meet specific low-emission standards and that these vehicles and other program equipment remain at the airport for their useful life.

14. Air Traffic Control Activities and Adopting Approach, Departure and Enroute Procedures for Air Operations

The preamble to the General Conformity Rule ^[51] states that:

“In order to illustrate and clarify that the de minimis levels exempt certain types of Federal actions, several de minimis exemptions are listed in § 51.853(c)(2). There are too many Federal actions that are de minimis to completely list in either the rule or this preamble.”

As an illustration of exempt actions, EPA states in the preamble that “Air traffic control activities and adopting approach, departure and enroute procedures for air operations” are among other actions that are de minimis (preamble, p. 63229, I(2)) and should be exempt from the Rule. The FAA concurs with the EPA determination that air traffic control activities are de minimis. However, because these activities are cited in the preamble but not in the Rule itself, the FAA believes that it is prudent to document these activities as presumed to conform.

Air traffic control activities are defined as actions that promote the safe, orderly, and expeditious flow of aircraft traffic, including airport, approach, departure, and enroute air traffic control.^[52] Airspace and air traffic actions (e.g., changes in routes, flight patterns, and arrival and departure procedures) are implemented to enhance safety and increase the efficient use of airspace by reducing congestion, balancing controller workload, and improving coordination between controllers handling existing air traffic, among other things. Although increased efficiency and delay reduction would allow traffic volume to increase, in FAA's experience such actions do not lead to increased annual aircraft operations or changes to the operational level of airports in the vicinity of the air traffic changes. In today's deregulated environment, market forces determine where airlines fly and how often.

Emissions released into the atmosphere above the inversion base for pollutant containment, commonly referred to as the “mixing height,” (generally 3,000 ft. above ground level) do not have an effect on pollution concentrations at ground level.^{[53, 54]} Therefore, air traffic control actions above the mixing height are presumed to conform.

In addition, the results of FAA research on mixing heights indicated that changes in air traffic procedures above 1,500 ft. AGL and below the mixing height would have little if any effect on emissions and ground concentrations.^[55] Such actions in the vicinity of the airport are tightly constrained by runway alignment, safety, aircraft performance, weather conditions, terrain, and vertical obstructions.^[56] Accordingly, air traffic actions below the mixing height are also presumed to conform when modifications to routes and procedures are designed to increase safety, enhance fuel efficiency, or reduce community noise impacts by means of engine thrust reductions. Other air traffic procedures and system enhancements that are presumed to conform include actions that have no effect on air emissions or result in air quality improvements, such as gate hold procedures which reduce queuing, idling, and flight delays.

15. Routine Installation and Operation of Airport Navigation Aids

Aviation navigation aids represent the facilities and equipment used for communications, navigation, and surveillance (CNS) systems.^[57] The use and maintenance of CNS systems is essential to safe air commerce and national security.^[58] Airports are required to establish adequate maintenance systems for navigational aid facilities to the level of performance achieved at original commission.^[59]

Similar to the previous presumed to conform action for air traffic control activities, EPA states in the preamble that “routine installation and operation of aviation (and maritime) navigation aids” are below de minimis and should be considered exempt actions.^[60] The FAA concurs with EPA in this determination. However, because the stated activities are cited in the preamble but not in the Rule itself, the FAA believes that it is prudent to document these activities as presumed to conform.

The routine installation, in-kind replacement, and maintenance of navigational aids (e.g., Air Traffic Control Towers (ATCT), Instrument Landing Systems (ILS), Approach Light Systems (ALS)) are presumed to conform because these activities will not generate emissions that exceed de minimis levels. Moreover, emissions generated by construction equipment and maintenance vehicles used to transport workers and equipment to CNS system sites are negligible considering the temporary nature of construction and maintenance activities and the limited number of vehicles involved.

If the installation of new or upgraded navigational aids for improved safety and efficiency also increases the capacity of the airport or changes the operational environment of the airport, these CNS activities are not presumed to conform.^[61]

Also presumed to conform are CNS emergency or standby generators powered by natural gas or LPG. These generators provide electric power in case of primary power failure and are operated intermittently, with an estimated total time of operation of less than 100 hours per year. Because of the infrequent use and small size (135 kilowatts or less) of the engine generators and the use of clean-burning fuels, the engine generators produce negligible air emissions.

IV. How To Apply Presumed To Conform Actions

The qualifying project categories discussed in the preceding section may be referred to as the FAA “presumed to conform list.” As authorized under the CAA, the list provides an additional way for the FAA to improve its environmental program management while still ensuring that agency air quality goals and requirements are met. Use of the list will reduce review times, eliminate unnecessary paperwork, clarify analytical requirements for all project actions, and insure that the proper level of documentation is applied in each case. Moreover, in some instances, the presumed to conform list can provide another method that the FAA and airport sponsors can use to demonstrate conformity with an applicable SIP.

When applying the presumed to conform list, the FAA must determine whether a proposed presumed to conform action has independent utility under the National Environmental Policy Act (NEPA) ^[62] or whether such action is part of a combined or larger action that might result in cumulative air quality impacts.^[63]

The proposed project has independent utility. If a presumed to conform project has independent utility, no general conformity evaluation or applicability analysis is required and agency officials may simply document that the project action is considered presumed to conform on the basis of this Notice and the applicable project category.

This allowance meets a major intent of presumed to conform—namely to reduce the analysis burden for actions that have little or no direct or indirect emissions. In its separate analysis of each project category in the presumed to conform list, the FAA has shown that the resulting emissions from any presumed to conform action would always be below the applicable de minimis thresholds.^[64]

The proposed project is a combined action. If a presumed to conform action is part of a combined action (e.g., an EIS or large EA generally), agency officials may exclude the emissions of one presumed to conform action from the calculation of total direct and indirect emissions in the applicability analysis and, if required, a general conformity determination. In combined actions, however, emissions from the presumed to conform action must be analyzed, quantified, and clearly documented in the applicability analysis or general conformity determination if required. Further discussion of this allowance is provided below.

Combined actions are considered connected actions under NEPA, which the Council on Environmental Quality (CEQ) defines as actions that are closely related and that:

—Automatically trigger other actions which may require environmental impact statements

—Cannot or will not proceed unless other actions are taken previously or simultaneously

—Are interdependent parts of a larger action and depend on the larger action for their justification ^[65]

Effective implementation of the presumed to conform list requires a balance between NEPA considerations on connected actions and the permitted exclusion of presumed to conform emissions under the Rule. As stated in § 93.152 under Definitions: “The portion of emissions which are exempt or presumed to conform under Section 93.153(c), (d), (e), or (f) are not included in the “total of direct and indirect emissions.” Similarly, the preamble (58 FR 63233) states: “The final rule requires the inclusion of the total direct and indirect emissions in the applicability and conformity determinations, except the portion of emissions which are exempt or presumed to conform * * *”

The approach adopted herein for the presumed to conform list is consistent with the Rule and places a conservative limit on the permitted exclusion of presumed to conform emissions. Moreover, based on interagency communications with the EPA, the agency's approach conforms to the EPA's belief that a Federal agency may exclude the emissions of one presumed to conform action from the applicability analysis of total direct and indirect emissions that are not otherwise exempt and from a conformity determination if required. As a result, even if a combined action includes multiple presumed to conform actions, the FAA and airport sponsors may only exclude the emissions from one presumed to conform action vis-à-vis the project's total direct and indirect emissions. Agency officials maintain the right to select the specific presumed to conform action to exclude if more than one is present in the combined action.

By being able to exclude emissions from a presumed to conform action, the agency may show that the project's total direct and indirect emissions that are not otherwise exempt do not equal or exceed any of the de minimis thresholds in the Rule. The presumed to conform action could therefore make a difference as to whether or not a general conformity determination is required. Specifically, the applicability analysis of total direct and indirect emissions, plus emissions calculated separately for the presumed to conform action, could show that the combined action would equal or exceed the de minimis thresholds if not for the allowable subtraction of emissions from the presumed to conform action.

In a combined action, the presumed to conform action must be evaluated similarly and at the same level as other elements in the overall project. This assessment typically involves the quantification of direct and indirect emissions on a calendar year basis. The estimated annual emissions from the presumed to conform action must be identified as a separate line item in the applicability analysis and clearly explained and presented in the study documentation.

Regional Significance

Under 40 CFR 93.153(j) of the Rule, a Federal action that is presumed to conform action may still be subject to a general conformity determination if the action is shown to be regionally significant.^[66] The purpose of the regionally significant requirement is to capture those Federal actions that fall below de minimis threshold levels but still have the potential to impact the air quality of a region.

By definition, if the total of direct and indirect emissions of any pollutant from a Federal action represent 10 percent or more of a maintenance or nonattainment area's total emissions of that pollutant, the action is considered to be a regionally significant activity and the General Conformity Rule applies. If an action in a nonattainment area is below the thresholds or is otherwise presumed to conform and is not regionally significant, then the General Conformity Rules does not apply and no official reporting is required under Section 176(c) of the CAA.

The FAA Air Quality Handbook states that an airport project that is presumed to conform is unlikely to have emission levels that are regionally significant.^[67] This is because, based on the highest de minimis threshold level (100 tons per year), in order for an action's net emissions to represent 10 percent or more of a maintenance or nonattainment area's total emissions of a particular pollutant, the area's total emissions inventory for any pollutant must be less than 1,000 tons, which is unlikely. Based on this rationale, the presumed to conform activities in this Notice are not considered to be regionally significant.

Issued in Washington, DC on February 5, 2007.

Charles R. Everett, Jr.,

Manager, Planning and Environmental Division, Office of the Associate Administrator for Airports.

Footnotes

1.  Clean Air Act Title I Air Pollution Prevention and Control, Part D, Subpart 1, Section 176 Limitation on Certain Federal Assistance.

2.  40 CFR Part 93, § 93.153(f).

3.  NAAQS established by the EPA represent maximum concentration standards for criteria pollutants to protect human health (primary standards) and to protect property and aesthetics (secondary standards).

4.  FAA calculated SO_X is considered equal to SO₂.

5.  Smaller PM_2.5 particulate matter is a subset of PM₁₀. Levels for PM_2.5 are included in the NAAQS but not yet established for purposes of general conformity (no de minimis threshold or SIPs). Therefore, references in this Notice to PM₁₀ also apply to PM_2.5 for purposes of presumed to conform actions.

6.  40 CFR Part 93, § 93.153(g).

7.  40 CFR Part 93, § 93.153(g)(1).

8.  Title 40 CFR Part 93, 93.153(g)(2).

9.  Ibid.

10.  Title 40 CFR Part 93, 93.153(h).

11.  58 FR 63228 (Nov. 30, 1993).

12.  12 58 FR 63229 (Nov. 30, 1993).

13.  CAA, § 175A, 42 U.S.C. § 7505a.

14.  49 U.S.C. 1601 et seq.

15.  40 CFR Part 93, § 93.153(b).

16.  “Conformity evaluation” refers to the overall process of assessing whether an action/project is subject to general conformity requirements, which may include an applicability analysis needed to make a conformity determination. See Question #1, EPA and FAA General Conformity Guidance for Airports: Questions and Answers, September 25, 2002.

17.  40 CFR Part 93, § 93.153(h)(2).

18.  40 CFR Part 93, §§ 93.153(h)(1)-(2).

19.  40 CFR Part 93, § 93.153(h)(3).

20.  40 CFR Part 93, § 93.153(h)(4).

21.  Depending on numerous factors affecting surface conditions, airports will generally resurface asphalt runways every 7-10 years.

22.  Airport “sponsors” are planning agencies, public agencies, or private airport owners/operators that have the legal and financial ability to carry out the program requirements for FAA financial assistance.

23.  Airports located in nonattainment or maintenance areas with small regional emission budgets may need to check whether a proposed exempt action might be regionally significant under 40 CFR Part 93, § 93.153(i).

24.  FAA Order 1050.1E, Chapter 3 (CATEX) and Chapter 4, section 406 (FONSI), pursuant to the National Environmental Policy Act.

25.  The Gross Vehicle Weight Rating (GVWR) system defines a Class 7 diesel truck as one that can carry 26,001 to 33,000 pounds of weight on two axles.

26.  EPA Report 460/3-91-02, November 1991, Nonroad Engine and Vehicle Emission Study—Report.

27.  EPA Report NR-005A, December 9, 1997, revised June 15, 1998, Median Life, Annual Activity, and Load Factor Values for Nonroad Engine Emissions Modeling.

28.  Calculations of maximum paint volume include consideration of construction equipment.

29.  Short tons, where one ton equals 2,000 lbs.

30.  The limiting pollutant is defined as the criteria pollutant that first exceeds de minimis levels for a given project.

31.  FAA AC 150/5320-6D, September 7, 1995, Airport Pavement Design and Evaluation.

32.  As recommended under FAA AC 150/5320-16, October 22, 1995, Airport Pavement Design for the Boeing 777 Airplane.

33.  Stabilized base layers as necessary for new pavements designed to accommodate jet aircraft weighting 100,000 pounds or more. FAA AC 150/5320-6D, September 7, 1995, Airport Pavement Design and Evaluation.

34.  Portland cement is a hydraulic cement made by heating a mixture of limestone and clay in a kiln and pulverizing the resulting material.

35.  FAA AC 150/5320-6D, September 7, 1995, Airport Pavement Design and Evaluation.

36.  EPA Report 460/3-91-02, November 1991, Nonroad Engine and Vehicle Emission Study—Report. Table 2-07 Emission Factors.

37.  EPA Report NR-005A, December 9, 1997, revised June 15, 1998, Median Life, Annual Activity, and Load Factor Values for Nonroad Engine Emissions Modeling.

38.  EPA Report 460/3-91-02, November 1991, Nonroad Engine and Vehicle Emission Study—Report.

39.  EPA Report NR-005A, December 9, 1997, revised June 15, 1998, Median Life, Annual Activity, and Load Factor Values for Nonroad Engine Emissions Modeling.

40.  A boiler is an encased vessel that provides a means for combustion heat to be transferred into water until it becomes steam. The steam is then used to heat the building through a network of pipes. When water is boiled into steam its volume increases about 1,600 times, which is an efficient means for transferring heat for a process. HVACWebTech, Inc.

41.  FAA AC 150/5360-13, April 22, 1988, Planning and Design Guidelines for Airport Terminal Facilities.

42.  FAA, 2005, Emissions and Dispersion Modeling System EDMS Version 4.2.

43.  Assuming a 100,000 sq. ft. one-floor building would require approximately 2.4 million cubic meters of natural gas to heat the building, annually; based on the industry standard heat value, 1,000 BTU per cubic foot of natural gas, annually [Airtron Heating and Air Conditioning, Columbus, Ohio].

44.  40 CFR Part 93, 93.153(d)(1).

45.  FAA Aviation Security Directive issued February 2002.

46.  40 CFR Part 93, 93.153(e).

47.  Ibid.

48.  FAA AC 150/5300-13, September 29, 1989, Airport Design.

49.  Per index under 14 CFR Part 139, 139.319(a).

50.  FAA Order 5100.38C, Airport Improvement Program Handbook, June 2005, §§ 580, 585.

51.  58 FR 63229 (Nov. 30, 1993).

52.  14 CFR Part 170, § 170.3.

53.  EPA Report, Procedures for Emission Inventory Preparation, Volume IV: Mobile Sources [420-R-92-009], section 5.2.2., 1992.

54.  Realistic Mixing Depths for Above Ground Aircraft Emissions, Journal of the Air Pollution Control Association, Vol. 25, No. 10, Howard M. Segal, Boeing, 1975.

55.  Report on “Consideration of Air Quality Impacts by Airplane Operations At or Above 3,000 feet AGL,” FAA-AEE-00-01, September 2000, p. 5.

56.  FAA Advisory Circulars No. 25-13 and No. 91-53A describe requirements that must be met when using reduced power for takeoff.

57.  14 CFR 171.1-171.51.

58.  14 CFR 169.1(a)

59.  14 CFR Part 171.

60.  58 FR 63229, I(6) (Nov. 30, 1993).

61.  Consistent with FAA Order 1050.1E, Section 401 “Actions Normally Requiring an Environmental Assessment”

62.  40 CFR 1506.1(c)(1), Council on Environmental Quality, Regulations for Implementing the Procedural Provisions of NEPA.

63.  40 CFR 1508.25(1)

64.  The FAA did no evaluate combined emissions from two or more presumed to conform categories.

65.  40 CFR 1508.25(1).

66.  A regionally significant Federal Acton is an action that has total emissions (the sum of direct and indirect emissions) that represent 10 percent or more of a nonattainment or maintenance area's total emissions of that pollutant [40 CFR Part 93, § 93.153(i) and (j)].

67.  FAA and USAF, April 1997, Air Quality Procedures for Civilian Airports & Air Force Bases.