Air Quality Help

The Air Emissions Guide to DAF Stationary Sources (Stationary Source Guide) provides guidance for estimating emissions for stationary sources of pollutant emissions commonly found at DAF installations. This guide provides updated emission factors and recommended calculation methodologies for these common sources associated with processes frequently occurring at DAF installations. The pollutants of concern addressed within this guide include criteria pollutants, Hazardous Air Pollutants (HAPs), Volatile Organic Compounds (VOCs), and greenhouse gases (GHGs). The June 2023 guide supersedes all prior versions of the Stationary Source Guide; older versions are considered obsolete.

The Air Emissions Guide to DAF Mobile Sources (Mobile Source Guide) provides guidance for estimating emissions for mobile sources of pollutant emissions commonly found at DAF installations. This guide provides updated emission factors and recommended calculation methodologies for processes and sources such as flight operations, Aerospace Ground Equipment (AGE) use, and both non-road vehicles/equipment and on-road vehicle operation. The pollutants of concern addressed within this guide include criteria pollutants, Hazardous Air Pollutants (HAPs), Volatile Organic Compounds (VOCs), and greenhouse gases (GHGs). The June 2023 guide supersedes all prior versions of the Mobile Source Guide; older versions are considered obsolete.

The Air Emissions Guide to DAF Transitory Sources (Transitory Source Guide) provides guidance for estimating emissions for transitory sources of pollutant emissions found at DAF installations. Transitory sources of emissions are those that are non-routine and/or seasonal sources (which may be stationary, mobile, or neither) that are short-term in nature. The sources included in this guide include bulk storage tank cleaning, seasonal equipment, fuel spills, hot mix asphalt plants, prescribed burns, wildfires, construction, site restoration/remediation, and land use changes. Transitory sources have historically often been erroneously included in stationary or mobile source air emission inventories, though these sources should only be accounted for in evaluating potential air quality impacts of proposed actions under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA); National Environmental Policy Act (NEPA); General Conformity; etc.. The pollutants addressed within this guide include criteria pollutants, Hazardous Air Pollutants (HAPs), Volatile Organic Compounds (VOCs), and greenhouse gases (GHGs). The June 2023 guide supersedes all prior versions of the Mobile Source Guide; older versions are considered obsolete.

While the details on assessing GHGs and climate change under NEPA is currently (August 2023) in flux, the requirement for assessing a proposed action's potential impact to air quality (include GHGs, as a regulated pollutants) is still mandated under the 2023 GHG Guidance. The Greenhouse Gas (GHG) & Climate Change Assessment Guide provides guidance on how to consider the impact agency projects has on GHG emissions and climate change.

The Air Quality EIAP Guide provides comprehensive instructions for assessing air quality impacts associated with DAF proposed action. The guide supplement 32 CFR 989, Environmental Impact Analysis Process, with guidance, procedures, and methodologies for meeting the air quality-specific requirements of the National Environmental Policy Act (NEPA) and Council on Environmental Quality's (CEQ's) Regulations for Implementing the Procedural Provisions of NEPA (40 CFR 1500-1508). Additionally, the guide incorporates compliance requirements for 40 CFR 93 Subpart B, Determining Conformity of General Federal Actions to State or Federal Implementation Plans, and supersedes all other versions.

This guide is a continuation of the DAF Air Quality EIAP Guide and provides comprehensive instructions for performing a Level III, Advanced Air Quality Assessment, and overseas EIAP. The guide provides step-by-step instructions for performing Levels III air quality EIAP assessments and is intended to assist Air Quality Program Managers and/or Environmental Specialists in assessing advanced air quality impacts, if needed, of the DAF proposed actions. It provides guidance, procedures, and methodologies for use in carrying out air quality assessments for overseas EIAP and advanced quantitative and qualitative air quality EIAP assessment (which includes General Conformity Determinations).

The Air Quality Quantitative Assessment, Insignificance Indicators provides the technical basis of the DAF established significance indicators. Air emissions insignificance indicators are annual net change in emissions values that have been documented as clearly insignificant and therefore they do not cause or contribute to exceeding one or more NAAQSs. Insignificance indicators are used in NEPA/Conformity net-change inventory analyses to screen out DAF actions from further assessment when an action clearly has an insignificant impact on air quality. While insignificance indicators do not identify if actions are significant, they do allow for identifying actions that are truly de minimis or clearly insignificant impacts. This guide also discusses the assessment of greenhouse gas insignificance, which is when an action does not significantly cause or contribute to increase adverse climate change.

The PTE Guide provides standardized guidance and methodologies for establishing base-level PTE estimates for major source determinations. The guide evaluates DAF sources for physical and/or operational limitations to establish DAF-specific PTEs for individual source categories based on the Environmental Protection Agency's historic guidance and methodologies.

Most, if not all, DAF installations have some type of air permit. The permits range in complexity from a basic permit-by-rule (for small emission units) to a Title V permit (facility-wide permit for installations that are major sources). The Air Permitting Guide furnishes air quality personnel at DAF installations with the fundamental aspects of air permitting common to DAF installations. A well-written and relevant air permit simplifies the verification of compliance for both the permittee and regulating authorities, reducing the risk of noncompliance with air quality regulations.

New Source Review (NSR) is a preconstruction analysis and permitting program. When an NSR permit is required, an evaluation is necessary to ensure the most up to date pollution controls are utilized. Understanding the terms and concepts used in the NSR permitting program is essential. The Guide provides the DAF with a structured step-by-step approach for navigating through the applicability analysis and permitting complexities of NSR that are unique to DAF installations.

Most Air Force installations have some form of an Air Emission Inventory (AEI) requirement; however, preparing and updating an AEI for an Air Force installation is complex due to the unique and wide array of air emissions sources. The Air Program Information Management System (APIMS) AEI Procedures Guide provides instructions for producing a complete and accurate AEI for Air Force installations. The APIMS AEI Procedures Guide includes basic data set up along with specific instructions for most common air emission sources found on an Air Force installation. Each source category chapter details the specific data collection requirements and proper calculation methodologies specific to that air emissions source.

The purpose of the DAF Guide for boilers located at Area Sources of Hazardous Air Pollutants is to provide certain Air Force personnel (technicians, boiler operators, etc.) with a general understanding of key requirements for complying with 40 CFR 63 Subpart JJJJJJ, National Emission Standards for Hazardous Air Pollutants for Area Sources: Industrial, Commercial, and Institutional Boilers (commonly referred to as Subpart JJJJJJ). Subpart JJJJJJ applies to boilers located at commercial, industrial, and institutional Area Source facilities that burn coal, oil, biomass, or other solid and liquid non-waste materials. An "Area Source" HAP facility emits less than 10 tons per year of any single air toxic and less than 25 tons per year of any combination of air toxics.

The purpose of the United States Air Force (DAF) Stationary Internal Combustion Engine (ICE) Guide is to provide certain Air Force personnel (generator operators, Air Program Managers, etc.) with a general understanding of key requirements for complying with three interrelated stationary ICE air emission rules: National Emissions Standards for Hazardous Air Pollutants for Stationary Reciprocating Internal Combustion Engines (40 CFR Part 63, Subpart ZZZZ), New Source Performance Standards for Stationary Compression Ignition (40 CFR Part 60, Subpart IIII), and New Source Performance Standards for Stationary Spark Ignition Internal Combustion Engines (40 CFR 60, Subpart JJJJ). The DAF frequently uses stationary (e.g., remains in one location for more than 12 consecutive months) ICE to power equipment necessary to provide essential services (e.g., medical care, fire suppression) and critical mission support (e.g., flight line operations, communications).

The purpose of the DAF Guide for boilers located at Area Sources of Hazardous Air Pollutants is to provide certain Air Force personnel (technicians, boiler operators, etc.) with a general understanding of key requirements for complying with 40 CFR 63 Subpart DDDDD, National Emission Standards for Hazardous Air Pollutants for Major Sources: Industrial, Commercial, and Institutional Boilers (commonly referred to as Subpart DDDDD or Boiler MACT). A "Major Area Source" HAP facility emits 10 tons per year or more of any single air toxic and less than 25 tons or more per year of any combination of air toxics.

The United States Air Force Guide to the Mandatory Greenhouse Gas Reporting and Tailoring Rules discusses the applicability, requirements, and calculation methodologies for each rule as it pertains to the DAF. The first part of the Guide covers the Mandatory Greenhouse Gas Reporting Rule (MGHGRR) which requires large emitters of greenhouse gases (GHG) to collect GHG emissions data under a U.S. Environmental Protection Agency (EPA) reporting system. The second part of the Guide covers the "Tailoring Rule" which incorporates GHG emissions into the existing Title V and Prevention of Significant Deterioration ("PSD") permitting requirements. The Tailoring Rule regulates the same pollutants that are subject to reporting under the MGHGRR. While the court invalidated a portion of the Tailoring Rule, it held up EPA's ability to regulate GHG emissions for facilities already regulated for other pollutants under the PSD permit.

Earth's global temperature has risen by 1.5 °F over the past century, and is projected to continue to rise. Small changes in the global temperature can translate to large and potentially dangerous shifts in climate and weather on a global scale and even at the state level. Many states have seen changes in rainfall, resulting in more floods, droughts, or intense rain, as well as more frequent and severe heat waves. Click on the EPA Logo to view EPA published climate change fact sheets for each state and territory.

The first GHG Tailoring Rule Fact Sheet (May 13, 2010) summarizes the EPA's Final Rule for Step 1 and Step 2; phasing in the GHG emission thresholds, applicability, and requirements.

The first GHG Tailoring Rule Fact Sheet (May 13, 2010) summarizes the EPA's Final Rule for Step 1 and Step 2; phasing in the GHG emission thresholds, applicability, and requirements.