Chapter 6 Air Emissions 6

CHAPTER 6 

Air Emissions

This chapter summarizes federal air emissions regulations for petroleum storage 

tanks and bulk gasoline terminals. Federal and state permitting requirements are 

summarized, as well as other general state requirements. Other information within 

this chapter includes:

 Sources of emissions from fuel storage tanks and loading racks

 Methods of controlling emissions from fuel storage tanks and loading racks

 Air quality regulations for fuel storage tanks, loading racks, and internal 

combustion engines

6.1 Regulatory Background

Congress first enacted federal clean air legislation in 1955, providing for research 

and technical and financial assistance to the states. After adopting several additional minor air pollution laws, Congress passed the Air Quality Act of 196

providing the basic framework of the current statutes. The Clean Air Act (CAA)

of 1970 and the CAA of 1977 helped shape the control of air pollution. Th

amendments of 1990 strengthened existing air pollution control programs and 

added a comprehensive operating permit program (Title V) to consolidate all

CAA requirements for major air pollution source

Exhibit 6−1 summarizes some of the key federal air quality programs applicable 

to fuel facilities included in the CAA A discussion of each of these programs 

provided in this section. You’ll need to contact your state or regional air quality 

agency to understand requirements specific to your facility. See Appendix E for

addresses, phone numbers, and websites for state air quality agencies.

Some of the CAA requirements and U.S. Environmental Protection Age

regulations summarized in this chapter address:

 National Ambient Air Quality Standards (NAAQS) to protect public health 

and welfare. PA has published NAAQS for six criteria poll

 Requirements for new industrial sources to be controlled by standards that,

at minimum, meet technology-based New Source Performance Standards 

(NSPS) applicable to classes or categories of industrial facilities.

 Toxic air pollutants, also called hazardous air pollutants (HAPs), which are

regulated separately from criteria air pollutants in the CAA. Federal Nationa

Emission Standards for Hazardous Air Pollutants (NESHAP) have been 

implemented to reduce AP emissions from new and existing sourc

 The Montreal Protocol and EPA’s Ozone Depleting Substances Ma

Program to phase out most ozone-depleting substances

 The prevention, detection, and corrective action for sudden, catastrophic

releases of certain air toxics and flammable substances by requiring that 

facilities evaluate public risk and develop a risk management program.

 Most facilities with bulk fuel storage 

tanks, loading operations, and 

vapor control need an air permit 

(40 CFR 70).

 The state or regional air quality 

control agency issues the permit 

that sets limits on polluting emissions and operations.

 Storage tanks subject to NSPS must 

have one of the following control 

methods or an equivalent system 

(40 CFR 60 Subparts K, Ka, and Kb):

– External floating roof

– Fixed-roof with internal floating 

cover

– Vapor recovery system that reduces VOC emissions

 Bulk gasoline terminals subject 

to NESHAP must have a vapor 

collection system to collect VOCs 

during loading operations with 

emissions to the atmosphere not 

exceeding 10 mg of VOC per liter of 

gasoline loaded (40 CFR 63 Subpart 

BBBBBB).

 If stationary internal combustion 

engines are not able to operated to 

manufacturer's specification, you 

must demonstrate compliance, 

conduct testing, monitor, and keep 

records (40 CFR 60 Subparts IIII and 

JJJJ, and 40 CFR 63 Subpart ZZZZ).

The Law Says
6-2 Chapter 6 Air Emissio

 Permit programs for the operation of major and area sources emitting air

pollutants. PA has delegated air permitting to state, regional, or local a

quality agencies.

6.2 Emission Sources

The majority of air emissions at fuel facilities are caused by evaporation from one

or more of the following:

 Storage tank

 Loading and unloading racks

 Equipment leak

 Accidental release

EXHIBIT 6−1

Air Compliance Programs Potentially Applicable to DLA Energy Facilities

Air Compliance 

Program Summary of Air Program Applicable FederalRegulatory Reference

New Sourc

Performance Standar

Regulates certain air emission sources,

such as petroleum storage tanks, bulk 

gasoline terminals, and stationary internal 

combustion engines

40 CFR 60, Subparts 

K, Ka, Kb, XX, IIII, 

National Emissio

Standards for

Hazardous Ai

Pollutant

Regulates facilities that emit hazardous

air pollutants, such as gasoline 

distribution facilities and stationary 

internal combustion engines

40 CFR 63, Subparts 

R, EEEE, ZZZZ, GG

BBBBBB, CCCCCC

National Ambient A

Quality Standard

Established for the following criteria air

pollutants: particulate matter, NO2, S

CO, lead, and ozon

40 CFR 5

Major New Sour

Revie

Has stricter regulation of NAAQS crit

pollutants for new construction or 

modification to sources and may include 

registrations or permits

40 CFR 52.21 and

various state and local 

regulations

Title V Permit Program Establishes uniform permitt

requirements to be implemented by 

states for all major sources

40 CFR 70 and various

state and local 

regulations

Accidental Releas

Prevention Progr

Helps prevent accidental releases of

acutely hazardous materials (AHM

and requires Risk Management Pla

for facilities that store AHMs in excess 

threshold quantities

40 CFR 6

Ozone-Depleting

Substance

Requires the phaseout of certain

chemicals often used in air conditioning 

and fire suppression systems. Requires

a trained and certified technician to 

handle regulated refrigerants, perform 

leak detection and repairs, and maintain 

records.

40 CFR 8
Chapter 6 Air Emissions 6

6.2.1 Storage Tanks

Storage tanks are a common cause of air emissions at fuel facilities. In a typica

tank, the space over the top of the liquid becomes saturated with the vapor of 

the stored liquid. These saturated vapors can be released from the tank into the

atmosphere in a number of different ways, such as:

 Expansion and contraction of the vapors because of temperature and

barometric pressure changes

 Displacement of the vapors during filling

 Direct evaporation (exposure to the air)

There are two basic storage tank designs used to store petroleum liquids: fixedroof tanks and floating-roof tanks. Floating-roof tanks can be subdivided into

internal floaters and external floaters. Floating-roof tanks have less emissions 

than fixed-roof tanks because tank roofs float on the stored liquid to essentially 

eliminate liquid losses due to vapor displacement.

6.2.1.1 Fixed-roof Tanks

A fixed-roof tank consists of a cylindrical steel shell with a permanent roof (coneshaped, dome-shaped, or flat). Fixed-roof tanks are either freely vented or have

a pressure vent. The pressure vent lets the tank operate at either a slight vacuum

or a slight positive internal pressure to minimize the release of vapors during operation. Fixed-roof tanks can be installed as either aboveground or underground 

storage tanks. Exhibit 6−2 shows a typical aboveground fixed-roof tank.

EXHIBIT 6−2

Typical Aboveground Fixed-roof Tank

Fixed-roof tanks have two types of emission losses: breathing losses and working losses. Breathing losses occur when vapor is released as it expands and 

contracts because of temperature or pressure changes. Working losses occur 

as a result of liquid level changes in the tank that force fuel-vapor-saturated air 

out of the tank through a vent. When the tank is emptied, air drawn into the 

tank becomes saturated with fuel vapor. When the tank is filled, these vapors are 

expelled from the tank.
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Fixed-roof tank emissions can be controlled by installing a vapor balance 

system, a vapor recovery system (discussed later in this chapter), or an internal 

floating roof (conversion to an internal floating-roof tank).

6.2.1.2 External Floating Roof Tanks

External floating-roof tanks consist of an open-topped cylindrical steel shell with

a roof or deck that floats on the surface of the stored liquid. The floating-roof

deck rises and falls with the liquid level in the tank (see Exhibit 6−3). The floating-roof deck includes a rim seal system to control the release of vapors. The sea

system is used to control the evaporative losses from the space between the tank 

wall and the floating-roof deck. The seal system slides against the tank wall as the

roof is raised and lowered.

External floating-roof tanks have two types of emission losses: standing storage

losses and withdrawal losses. Standing storage losses are defined as rim seal 

losses and deck fitting losses. Standing storage losses occur as fuel vapors escape

from gaps in the rim seals (the space between the floating-roof seals and the tank 

wall) and from small openings in the floating roof for deck fittings. The amount of

rim seal loss depends on the rim seal system used. Installing two separate seals

can reduce standing storage losses. The first seal is called the primary seal, and

the other, mounted above the primary seal, is called the secondary seal.

Withdrawal losses occur when an external floating roof is lowered. The liquid

that clings to the tank wall is exposed to the atmosphere and evaporates. 

Installing wiper blade seals around the edge of the roof is one way to reduce

withdrawal losses.

6.2.1.3 Internal Floating-roof Tank

The internal floating-roof tank has a permanent fixed roof with a floating roof

inside. Internal floating-roof tanks have either a contact roof or deck floating on

the liquid surface or a non-contact deck several inches above the liquid surface 

resting on pontoons. These decks rise and fall with the liquid level within the

fixed-roof tank. Circulation vents and an open vent at the top of the fixed roof reduce vapor accumulation in concentrations approaching flammable range. Some

internal floating-roof tanks also have internal columns that support the fixed roof.

Most internal floating-roof tanks have the same types of evaporative losses that

external floating-roof tanks do—working losses and standing storage losses. 

Working losses and standing storage losses will increase if the tank has internal 

column supports. The liquid fuel coats the columns and evaporates. Standin

losses from internal floating-roof tanks result from evaporation of liquid fuel from 

around the rim seals and deck fittings. Other standing losses include breathing

losses resulting from ambient temperature and pressure changes.

Internal floating-roof tanks have two types of primary seals: resilient foam-filled

and wiper. These seals close the ring of vapor space between the edge of the

floating roof and the tank wall.  resilient foam-filled seal consists of a foam

material surrounded by fabric that expands and contracts to maintain contact 

with the tank wall. Wiper seals are usually flexible perimeter seals or wipers that 

slide against the tank wall as the tank roof moves up and down.

EXHIBIT 6−3

Schematic of External Floatingroof Tank
Chapter 6 Air Emissions 6

6.2.2 Loading and Unloading Racks

Another way emissions occur at fuel facilities is due to evaporative losses that

occur when petroleum products are loaded and unloaded from storage and 

transportation vessels. Loading loss is generally the primary source of evaporative emissions from marine vessels, tank cars, and tank truck operations that 

occur when fuel vapors in the tank truck are vented to the atmosphere during 

fuel loading. Fugitive equipment leaks can also occur from gasoline cargo trucks. 

There are certain regulatory requirements for use of vapor-tight cargo trucks to

minimize fugitive emissions. As the fuel level in the tank rises during loading, it

displaces the vapors in the tank. One way you can control these emissions is to

install a vapor collection system.

As discussed below, gasoline distribution facilities are required to install and

operate vapor collection systems to control vapor emissions during gasoline 

loading operations. However, aviation gas and diesel fuel loading systems are not

required to use a vapor collection system.

Loading rack air emissions include emissions from fugitive leaks, spills, and loading 

operations. Different loading methods have different influences on working loss. 

Generally, there are two types of fuel loading: submerged loading and splash loading. The type of loading is determined by where the fill pipe terminates in the tank

6.2.2.1 Submerged Loading

Submerged loading has much lower evaporative loss than splash loading and

is preferred for loading fuels (on systems without vapor collection systems). The

submerged loading method introduces the fuel into the bottom of the tank 

below the liquid level. This reduces liquid turbulence and vapor−liquid contact

There are two types of submerged loading methods: the submerged fill pipe

method and the bottom-mounted fill pipe method. The bottom-mounted fill

pipe method is the preferred practice at DLA Energy fuel facilities. In the submerged fill pipe method, the fill pipe descends to below the level of the liqui

and the opening is almost at the bottom of the cargo tank. In the bottom-mounted fill pipe method, the fill pipe enters the cargo tank from the bottom

6.2.2.2 Splash Loading

As noted earlier, splash loading results in higher vapor emissions than submerged loading. In splash loading, fuel enters the tank through a fill pipe at th

top and splashes as it hits the liquid surface (or bottom). The splashing generates large amounts of vapors, which are vented from the tank as the fuel level

rises in the tank.

6.2.3 Equipment Leaks

Leaks and spills from faulty pumps or compressor seals, loose valve bonnets, fittings, pressure-relief devices, and flanges result in uncontrolled air emissions due 

to evaporation of the liquid fuel. The best way you can control these emissions

is to locate and repair the source of the leak. An inspection and maintenance

program will identify and help reduce equipment leaks resulting in air emissions.

You can reduce tank emissions by 

painting storage tanks white to reflect 

more sunlight. You can also insulate 

storage tanks to reduce heat gain 

and losses. Both measures reduce 

emissions by keeping tanks at a more 

constant temperature.

Don’t Forget...
6-6 Chapter 6 Air Emissio

6.2.4 Accidental Release

In the event of an accidental release, a fraction of the fuel is lost through evaporation. You cannot prevent these evaporative losses, but you can implement certain

procedures to prevent and minimize accidents. See Chapter 1, Environmental

and Emergency Response Planning for guidelines on Emergency Response Pla

and pollution prevention.

6.3 Emission Controls

There are several methods of controlling emissions from fixed-roof tanks. In addition to installing internal floating roofs and seals to minimize evaporative losses

you can use vapor balancing, vapor recovery, and thermal oxidation systems to 

control emissions.

6.3.1 Vapor Balancing

Vapor balancing is a method where the vapors being vented from a storage tank 

being filled are directed to the storage tank from which the fuel is being pumped. 

This technique is common at gas stations where the vapors vented from the

storage tank are returned to the tank truck. Vapor balancing can recover up to 

98% of vapors that would otherwise be vented to the atmosphere.

6.3.2 Vapor Recovery Systems

Vapor recovery systems are used to collect vapor emissions from storage tanks 

and condense them to a recoverable liquid product using several techniques. 

Carbon absorption systems can include refrigeration and compression cycles 

where highly concentrated vapors from storage tanks are piped to an absorption 

tower, where chilled liquid is sprayed into a column filled with an inert packing 

media. The chilled liquid causes vapors entering the bottom of the column to

condense and absorb onto the inert packing media. Droplets of the liquid eventually collect on the packing material and rain out into the bottom of the absorption column. The liquid recovered from the bottom of the absorption tower

is then sent back to storage. Vapor recovery system control efficiencies using 

absorption can be as high as 98%, depending on the design of the absorption 

unit, the type of equipment used, and the volatile organic compound (VOC) 

concentration of the emission streams. Exhibit 6−4 illustrates a simple schematic 

for an absorption tower vapor recovery unit for gasoline vapors.
Chapter 6 Air Emissions 6

EXHIBIT 6−4

Vapor Recovery Unit Using Absorption System

Carbon adsorption units can also be used for vapor recovery. Carbon adsorption 

processes typically involve the use of activated carbon, which is suitable for 

collecting VOCs from high-volume, low-concentration gases by adsorbing or

binding the vapors onto the active carbon. Activated carbon is a processed

material received from a vendor and is produced by heating coal, coconut shells, 

or wood in a pyrolysis process to drive off the VOCs, making the material “thirsty”

for VOCs. VOCs collected in an adsorption unit can be recovered by recycling th

activated carbon or other adsorption material in a process designed to capture 

the adsorption liquid, and the carbon or other adsorption material is regenerated 

and can be used again.

6.3.3 Thermal Oxidation Systems

In addition to vapor recovery systems, thermal oxidation systems can be used

to destroy the vapors. Thermal oxidation systems consist of either flares or

incinerators.

Flares are typically used to thermally destroy gaseous emissions from processes 

like refining, in which waste gas is generated and the emission of the gas without 

thermal destruction would be harmful. Flares may take different configurations, 

but they usually have a natural-gas-fired pilot that provides the combustion 

source. Waste gas is piped to the flare and ignited by the pilot, after which the 

flame is sustained until the waste gas diminishes. Destruction efficiency for 

most flares is greater than 95%, with the resulting emissions being the by-products of combustion and residual unburned hydrocarbons. 

Incinerators are another form of thermal oxidation used for destroying waste 

gases that otherwise would be harmful. Incinerators come in many different

configurations and sizes, but as with flares, their primary purpose is to destroy 

waste gas emissions. The vapor is injected through a burner manifold into the

combustion chamber of an incinerator. Thermal destruction efficiencies for
6-8 Chapter 6 Air Emissio

incinerators can be as high as 99%. Generally, incinerators are a more complex 

and expensive means of thermal oxidation than flares, but they achieve higher 

destruction efficiencies.

6.4 National Ambient Air Quality Standards 

Programs

The NAAQS are limitations on concentrations of criteria air pollutants that sh

not be exceeded anywhere in the U.S. To date, NAAQS have been establishe

the following compounds:

 Ozone (the standard is achieved by regulating hydrocarbons and VOC

 Nitrogen dioxide (N

 Particulate matter (PM−10 means particulates less than 10 micrometers 

diameter, and PM−2.5 means fine particulates less than 2.5 micrometers i

diameter)

 Carbon monoxide (CO

 Lead

 Sulfur dioxide (S

The NAAQS are numerical health-based criteria, so the regulated compo

are commonly referred to as criteria pollutants. To determine if the 

are being met, states are divided into air basins or air quality control regions. 

Ambient monitoring networks sample and analyze air for each of the criteria pollutants. If monitored concentrations are below the corresponding NAAQS, th

basin is designated as an attainment area. If monitored concentrations exceed

NAAQS, the air basin is designated as a nonattainment area for the exceed

pollutant. For CO and ozone, nonattainment areas are assigned a classification

depending on the severity of their nonattainment. Ozone nonattainment areas

can be classified as marginal, moderate, serious, severe, or extreme. See Exhibit

6−5 for a map of current ozone nonattainment areas in the U.S as of Novembe

30, 2018.

Areas also can be designated as a maintenance area if that area was designated

nonattainment for one of the NAAQS but later met the standards and was redesignated to attainment. To ensure the air quality in this area continues to 

the NAAQS, states are required to develop and implement Maintenance 

Implementation Plan

The air quality designation and classification of an area determines the major

source threshold for sources in that area. As discussed previously, this can affect

air permitting requirements for existing DLA Energy facilities. In addition, n

source review requirements for major new sources and major modifications at 

existing major sources of air emissions are different in attainment and nonattainment areas. These requirements are discussed later in this chapter under

6.10 , Air Permits.
Chapter 6 Air Emissions 6

EXHIBIT 6−5

8-Hour Ozone Nonattainment Areas

6.5 New Source Performance Standards

Most emissions from fuel facilities are VOCs and toxic air pollutants. N

exist for VOCs. However EPA has determined that VOCs contribute to the formation of ground-level ozone, which is a criteria poll

EPA identified a variety of processes and industries as having the potential 

emit criteria and certain other regulated air pollutants. For these processes 

and industrial categories, PA established technology-based emission contr

standards called NSPS. These apply to new, modified, or reconstructed statio

sources. SPS must reflect the “degree of emission limitation achievable thro

the application of the best system of emissions reductions,” taking cost into 

account. Facilities subject to SPS must comply with the standards regardless

the ambient air quality of the area.

While SPS regulate over 90 specific source categories, five differ

Subparts in 40 CFR 60 might apply to DLA Energy facilities, as foll

 SubpartA − General Provisi

 Subpart K − for petroleum storage tanks if construction, reconstruction, or

modification began after June 11, 1973, but before May 19, 197

 Subpart Ka − for petroleum storage tanks if construction, reconstruction, or

modification began after May 18, 1978, but before July 23, 198

 Subpart Kb − for volatile organic liquid (not just petroleum) storage tanks if

construction, reconstruction, or modification began after July 23, 1984

 Subpart XX − Standards for Bulk Gasoline Termin

EPA also established rules in two additionl NSPS subparts for certain stat

internal combustion engines. Engines typically emit nitrogen oxides (NOx),

particulate matter (PM), SO2, CO, non-methane hydrocarbons, and VOCs. In

8-Hour Ozone Nonattainment Areas (2015 Standard)

8-hour Ozone Classification

Extreme

Severe-17

Severe-15

Serious

Moderate

Marginal

Marginal (Rural Transport)

11/30/2018

Nonattainment areas are indicated by color.

When only a portion of a county is shown in color,

it indicates that only that part of the county is within

a nonattainment area boundary.
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combustion engines may be used at fuel facilities to power pumps or generate 

electricity and are covered by:

 SubpartIIII − for stationary compression ignition internal combus

engines

 Subpart JJJJ − for stationary spark ignition internal combustion engine

Once a permit to operate a fuel facility is issued, applicableNSPS emiss

standards and monitoring, recordkeeping, and reporting requirements become 

part of the permit conditions. The requirements for each of these standards are

summarized below. Refer to Chapter 12, Routine Reporting for more on

agency notification and reporting requirements.

6.5.1 Subpart A − General Provisions

The General Provisions contain numerous requirements that are generall

applicable to any source subject to an SPS unless otherwise noted withi

specific NSPS. Subart A requires written notificatin to EPA and the d

state agency of new source construction, reconstruction, or modification within 

30 days of commencement of the activity. Written notifications to PA also a

required at least 30 days before the anticipated facility startup (for example, 

filling of the tank), and again for the actual startup date. Notification is due within

15 days of the actual startup date.

Notification toEPA is required for any physical or operational change to

existing facility that may increase the emission rate of any air pollutant to which 

the SPS applies. This notice must be provided 60 days before the change

must include information describing the precise nature of the change, present 

and proposed emission control systems, productive capacity of the facility before 

and after the change, and the expected completion date of the change.

SubpartA define NSPS performance testing, monitoring, reporting, and co

device requirements (only if flares are installed). Except for the notification requirements and activities defined that constitute modification or reconstruction,

requirements of SubpartA should appear as permit condition

6.5.2 Subpart K − Petroleum Storage Tanks

NSPS Subpart K applies to each petroleum liquid storage tank with a capa

of 40,000 gallons or more for which construction or modification started between 

March 8, 1974, and May 19, 1978. This standard also applies to each petroleum 

liquid storage tank with a capacity of 65,000 gallons or more for which construction 

or modification started between June 11, 1973, and May 19, 1978. Storage tanks

covered under Subpart K must be equipped with a floating roof, vapor recovery

system, or equivalent method of control if they store petroleum liquids with true 

vapor pressures between 1.5 and 11.1 pounds per square inch absolute (psia). 

A vapor recovery system (or equivalent) is required if the tank stores petroleum

liquids with true vapor pressures above 11.1 psia. The true vapor pressure is the

absolute (partial) pressure of a petroleum liquid at its actual storage temperature 

measured either in units of psia or millimeters of mercury (mm Hg)

If your storage tanks are subject toNSPS Subpart K, you are required to mai

records of petroleum liquid stored, length of storage, and maximum true vapor 
Chapter 6 Air Emissions 6-

pressure of the liquid during the storage period for at least 2 years (or 5 years if 

your facility has a Title V operating permit). These monitoring requirements d

not apply to tanks that store petroleum liquids with a Reid vapor pressure (RV

less than 1.0 psia (provided the maximum true vapor pressure does not exceed 

1.0 psia) or tanks equipped with a vapor recovery and return disposal system.

6.5.3 Subpart Ka − Petroleum Storage Tanks

Subpart Ka is a more recent and more stringent emissions standard for petroleum

liquid storage tanks than Subpart K. Subpart Ka applies to your facility if you hav

a petroleum storage tank with a storage capacity over 40,000 gallons for which construction began after May 18, 1978, but before July 23, 1984. Like Subpart K, Subpar

Ka also does not apply to tanks that contain Nos. 2 through 6 fuel oils, Nos. 2

through 4-GT gas turbine fuel oils, or Nos. 2-D through 4-D diesel fuel oil

Storage tanks covered under Subpart Ka must be equipped with one of th

following:

 An external floating roof with primary and secondary rim seal

 An internal floating roof with all openings covered and gaskete

  vapor control system capable of reducing VOC emissions by 95 weigh

percent

 An equivalent method of VOC emissions contr

External floating-roof tanks must be inspected within 60 days of being initially

filled (or refilled if the tank was out of service for over 1 year). You are required 

to measure and record the gap areas and maximum gap widths between the 

primary seal and the tank wall and between the secondary seal and the tank wall. 

Inspections must be performed at least every 5 years for the primary seals and at

least annually for the secondary seals. Written notification must be provided to 

EPA and your state agency at least 30 days prior to testing. If any gap measurement test exceeds allowable limits, you must submit a reportto EPA an

state within 60 days of the inspection. You are also required to keep all records 

on-site for 2 years (or 5 years if your facility has a Title V operating permit) from

the date the record was created.

Care should be taken to ensure that any slotted guidepoles used at external 

floating roof tanks are installed with controls, such as gaskets, wipers, and pole 

sleeves.

Slotted guidepoles help guide the motion of the external floating roof and

sample the contents of the tank for environmental and quality control purposes. 

Without emission controls, these guidepoles operate as chimneys, emitting an 

estimated 20,000 pounds (lb) of VOCs annually per tank—roughly equal to the

emissions from 380 cars and trucks. The slots and the space between the guidepoles and the tank’s roof are observable emission pathways that violate the “no

visible gap” prohibition in SPS Subparts Ka an

Subpart Ka does not require any initial testing or monitoring for internal floating-roof tanks. If the tanks are equipped with a vapor control system, you mus

provide emissions data, manufacturer’s design specifications, and an Operations

and Maintenance (O&M) Plan 

Subparts K and Ka do not apply to 

tanks that contain Nos. 2 through 

6 fuel oils, Nos. 2-GT through 4-GT 

gas turbine fuel oils, or Nos. 2-D 

through 4-D diesel fuel oils because 

the rule specifically excludes these 

materials from the definition of a 

petroleum liquid.

Did You Know?
6-12 Chapter 6 Air Emissio

No actual testing is required, and no periodic inspections are required. Facilities

with tanks subject to Subpart Ka are required to perform the same monitoring

of operations (petroleum liquid stored, period of storage, maximum true vapor 

pressure of the liquid during the storage period, and so on) as tanks subject to 

Subpart K

6.5.4 Subpart Kb − Volatile Organic Liquid Storage Tanks

Subpart Kb is the most recent emissions standard for petroleum liquid storage

tanks. It is stricter than Subparts K and Ka. Subpart Kb applies to any volatile organic liquid storage tank that is not located at a bulk gasoline plant or service stati

and that has a capacity of over 75 cubic meters (19,810 gallons) that was constructed 

after July 23, 1984. The definition of volatile organic liquids is broader than petroleum liquids, as defined in Subparts K and Ka, so tanks constructed after July 23

1984, are more likely to be regulated by Subpart Kb. Monitoring, recordkeeping

and reporting requirements are significantly expanded in Subpart Kb

VOC emissions standards are similar for storage tanks covered under Subpart

Ka and Kb for tanks exceeding certain capacity thresholds and storing petroleum 

compounds exceeding certain thresholds. The key difference between the two

regulations is that under Subpart Kb, the internal and external floating-roof alternatives cannot be used if the stored liquid has a maximum true vapor pressure of 11.1

psia or higher. Subpart Kb requires tanks that store these more volatile liquids to

be equipped with a vapor control system capable of reducing VOC emissions by 95

weight percent, or with an equivalent method of VOC emissions control. Diesel and

other low volatility petroleum fuels may be stored in fixed roof tanks.

Inspection requirements for external floating-roof tanks are similar under

Subparts Ka and Kb. One notable difference is that if a Subpart Kb limit is exceeded, you are required to repair the tank or remove it from service within 

days, instead of reporting the exceedance to EPA, as is the case with Subp

Ka. Inspection requirements for internal floating-roof storage tanks subject to

Subpart Kb are similar to the requirements for external floating-roof tanks, with

some exceptions. First, internal floating-roof tanks must be visually inspected, 

and any defects discovered must be corrected prior to filling the tank. Visual 

inspections of the floating roof and both seals must be performed through 

manholes and roof hatches at least every 12 months after the first filling if the 

tanks are equipped with liquid-mounted or mechanical-shoe primary seals. For 

tanks equipped with double-seal systems, the same inspection frequency can 

be applied, or complete visual inspections can be performed every 5 years (not 

through manholes or roof hatches).

As is the case with Subpart Ka tanks, you must repair any defect in the seals o

gaskets within 45 days of discovery.  30-day extension may be allowed by the

agency if you are not able to drain the tank for repairs within the 45-day period 

due to extenuating circumstances. Visual inspection of all sealing systems is 

required each time the tanks are emptied and degassed, and PA (and the sta

agency) must be notified in writing at least 30 days before filling or refilling any 

storage tank subject to this requirement.
Chapter 6 Air Emissions 6-

For both external and internal floating-roof tanks, you must provide a description 

of primary and secondary seal systems and other control equipment installed on 

the tanks to PA within 15 days of initially filling the tank. Also, you are requi

to report the results of any inspections to PA within 30 days after the inspecti

and maintain all records on-site for 2 years (or 5 years if your facility has a Title V

operating permit) from the date the records were created.

If you have any Subpart Kb petroleum storage tanks that have vapor contro

systems, you are required to report measured emissions control efficiency to 

and the state within 6 months of initial startup of the system. Also, semiannual

reporting of vapor control system operation to PA and the state is require

You must maintain on-site records of O&M plans, measured values, and testin

performed on the vapor control system for 2 years (or 5 years if your facility has a 

Title V operating permit) from the date the records were created

6.5.5 Subpart XX − Standards of Performance for Bulk Gasoline 

Terminals

This standard applies to your facility if it has a daily gasoline throughput of

20,000 gallons (75,700 liters per day) or more and was constructed or modified after 

December 17, 1980. PA defines throughput as the maximum calculated desi

throughput as may be limited by compliance with enforceable conditions under 

federals, state, or local laws. If this applies to your facility, you must have a vapor

collection and control system to collect vapors from truck-filling operations. 

You are required to test the entire loading rack and vapor collection system for 

leaks at initial startup and monthly thereafter. You must document any leaks 

discovered, and repair them within 15 days of discovery, plus maintain on-site 

records of the monthly leak inspections for at least 2 years (or 5 years if your 

facility has a Title V operating permit)

Tanker trucks filled at these facilities are required to have documentation demonstrating that their cargo tanks are vapor tight. The tanker truck vapor-tightnes

documentation may either be maintained at the facility and be available for 

inspection or made available electronically or via FAX. If the electronic or F

option is used, the electronic copy must be available instantly and the FAX copy

must be made available in a relatively short, agreed upon time frame. Also, if

the electronic or FAX option is used, the permitting authority (EPA or your st

agency) is to be notified. This documentation must be updated annually. Thi

certificate should be provided by the tank truck shipping company. If the tanker

truck company cannot or will not provide a recent certificate, you cannot offer 

gasoline for transfer into their tank truck. Make sure you obtain the certificate

prior to loading the gasoline into the truck.

6.5.6 Stationary Internal Combustion Engines

There are twoNSPS subparts that apply to stationary internal combustion engines (ICE). 40 CFR 60Subpart IIII is applicable to stationary compress

ICE and 40 CFR 60 Subpart JJJJ is applicable to stationary spark ignition IC

rules do not apply to motor vehicles or portable non-road engines.
6-14 Chapter 6 Air Emissio

All new ICE owners must maintain documentation from the manufacturer th

their engine meets the Subpart IIII- or Subpart JJJJ-tiered engine emission standards for their engine displacement (liters per cylinder), power output (horsepower [hp] or kilowatt [kW]), and duty type (emergency generator, non-road en

marine engine). This documentation is called anEPA Certificate of Conform

(commonly referred to as a vendor certificate). The engine manufacturer must

provide this document, and all new ICE owners must maintain a copy of thi

document to certify that their engine is compliant with the emissions standards 

in SubpartIIII or Subpart JJJJ. Ask your engine manufacturer for a copy, or, 

don’t know your engine manufacturer, obtain one from your engine supplier. 

If your engine supplier cannot provide the certificate, you can obtain one from

EPA’s website listed in Section 6.13, For More Information. Chapter 12, Routi

Reporting provides additional details about the vendor certification requirement.

6.5.6.1 Subpart IIII - Stationary CI ICE

This standard applies to stationary diesel engines at your site used for tasks such as

generating power or electricity for pumps or compressors whose construction, modification, or reconstruction began after July 11, 2005. This type of engine does not have

a spark plug or other sparking device to cause fuel ignition; instead, fuel ignition 

is driven by compression. For this standard, the date of construction is considered 

to be the date the engine is ordered by the facility. The standard requires engine

manufacturers to produce engines that meet the SubpartIIII emissions standa

and to certify them as such, for engines produced for model year 2007 and after. 

A majority of engines ordered between July 11, 2005, and model year 2007 were

made to meet these standards and may be certified as such. If not, options for

alternate methods of compliance demonstration are provided in Subpart I

Contact your state agency for information on the full requirements.

These certified compression ignition internal combustion engines (CI ICE

are required to be operated and maintained according to the manufacturer’s 

written instructions. You may change only those emission-related settings that 

are permitted by the manufacturer.  stationary CI ICE equipped with a die

particulate filter to comply with emission standards must be installed with a 

backpressure monitor that notifies the operator when the high backpressure 

limit of the engine is approached.

The Subpar IIII emissions standards are primarily met by engine manufactu

Refer to the regulation for the specific emission limits that vary according to

installation date and engine speed. In addition, to lower SO2 emissions, Subp

IIII requires that diesel fuel with lowered sulfur content be used by owners 

operators of CI ICEs that use diesel fuel. If the CI ICE has a displacement s

less than 30 liters (7.9 gallons) per cylinder, beginning October 1, 2010, ultra-low

sulfur diesel (ULSD) fuel must be used. ULSD fuel, also known as S15, is U.

diesel fuel with a sulfur content not to exceed 15 parts per million (ppm). If the

CI ICE has a displacement size of equal to or greater than 30 liters per cylinde

fuel that meets a maximum per gallon sulfur content of 1,000 ppm must be used. 

Stationary CI engines used in Guam, American Samoa, remote areas of Alaska

the Commonwealth of the Northern Mariana Islands do not have to meet the

fuel requirements.
Chapter 6 Air Emissions 6-

Beginning June 1, 2012, CI ICE with a displacement size of greater than or equ

to 30 liters (7.9 gallons) per cylinder must use fuel that meets a maximum 

per-gallon sulfur content of 1,000 ppm.

Existing CI ICE that are modified or reconstructed after July 11, 2005, are a

regulated by Subpart IIII. If you do not install, configure, operate, and mai

your engine and control device according to the manufacturer’s emission-related 

written instructions, or you change emission-related settings in a way that is not 

permitted by the manufacturer, you must demonstrate compliance. However,

when an engine is modified or reconstructed, it keeps the same model year and 

must meet the standards for that original model year.

Refer to Chapter 12, Routine Reporting, for a summary of recordkeeping and

reporting requirements.

6.5.6.2 Subpart JJJJ - Stationary SI ICE

This standard applies to any size stationarySI engines at your site used for tas

such as generating power or electricity for pumps or compressors whose construction, modification, or reconstruction began after June 12, 2006. Spark ignition internal combustion engines (SI ICE) use a spark (across a spark plug) to 

ignite a compressed fuel-air mixture. Typical fuels for such engines are gasoline,

alcohol-based fuels, natural gas, propane, and liquefied petroleum gas. I engine

are further subdivided by power cycle, that is two-stroke versus four-stroke

and whether they are rich burn engines (burning with a higher amount of fuel 

as compared to air) or lean burn engines (less fuel compared to air). As with

Subpart IIII, the date of construction for Subpart JJJJ is considered to be the

the engine is ordered by the facility. The standard requires engine manufacturers

to produce engines that meet the Subpart JJJJ emissions standards and to certify

them as such. These certifiedSI ICE are required to be operated and mainta

according to the manufacturer’s written instructions. For instance, gasoline-fired 

SI engines must use gasoline that meets the per-gallon maximum sulfur limit i

40 CFR 80.195

The engine size or horsepower (hp), engine type (rich burn engine or lean burn

engine), and fuel used dictates the date specific engines manufactured must 

meet these emission standards. Contact your state agency for information on the 

specific requirements.

Engines that do not meet the standards applicable to non-emergency engines

must install a non-resettable hour meter prior to startup of the engine. Engines

equipped with a diesel particulate filter to comply with emission standards must 

install the diesel particulate filter with a backpressure monitor that notifies the 

owner or operator when the high backpressure limit of the engine is approached.

Facilities that do not follow the manufacturer’s emission-related O&M procedure

are considered to be operating a non-certified engine. Facilities that use non-certified engines have several requirements, depending on the engine’s horsepower, 

that may include initial and periodic performance tests, keeping a maintenance 

plan, records retention, and operating the engine in a manner consistent with 

good air pollution control practice for minimizing emissions. ExistingSI ICE 

are modified or reconstructed after June 12, 2006, are regulated by Subpart
6-16 Chapter 6 Air Emissio

JJJJ. However, when an engine is modified or reconstructed, it keeps the same

model year and must meet the standards for that original model year. Refer to

Chapter 12, Routine Reporting for a summary of recordkeeping and reporting 

requirements.

6.5.6.3 Emergency Use Engines

SubpartsIIII and JJJJ have specific requirements for emergency use engines 

as a subset of emergency use engines, for fire pumps. Emergency use engines are

any stationary ICE that are operated only in emergency situations. Examples 

emergency use are operations to provide power when the normal electric power 

is interrupted or to pump water in the case of fire or flood. Fire pumps are used to 

pump water for fire protection or suppression.

SubpartsIIII and JJJJ establish limitations on the hours that stationary emergency engines may be used for maintenance and readiness testing purposes,

non-emergencies, and for emergency demand response programs. There is no

time limit on the use during emergency situations. Emergency demand response

programs lead by local and regional transmission organizations are important 

programs that protect the reliability and stability of the national electric service 

grid in times of eminent blackouts. The hours spent for emergency demand

response operations and when there is deviation of voltage or frequency of 5% 

or greater below standard voltage or frequency are not limited. However, the

engine will not be considered an emergency engine and will need to meet all 

requirements for non-emergency engines in SubpartsIIII and JJJJ. Emer

stationary ICE may operate up to 50 hours per year in non-emergency situation

under certain conditions, but those 50 hours are counted toward the 100 hours 

per year provided for maintenance and testing.

Emergency CI ICE that do not meet the standards applicable to nonemerge

engines must have a non-resettable hour meter prior to startup of the engine. 

This requirement to have a non-resettable hour meter also applies to emergency

SI ICEs that are less than 130 hp and built on or after July 1, 2008; are 130 hp

greater but less than 500 hp and built on or after January 1, 2011; and are 500 

hp or greater and built on or after July 1, 2010. Hours of operation, both during

emergencies and for maintenance and testing, must be recorded.

Model year 2007 and beyond fire pumps must meet Subpart IIII and JJJJ emission standards specific to fire pumps, and these standards vary dependi

horsepower and model year.

The manufacturer’s certifications for ICE and maintenance records must 

maintained. Also, to meet thePM standard, some CI engines have a diesel particulate filter. These engines must have a backpressure monitor that indicates 

the high backpressure limit is approached, and you must maintain records that 

show this. StationarySI natural-gas-fired engines may use propane for a maximum of 100 hours per year solely during emergency operations. Certified engines with control devices must be operated and maintained according 

manufacturer’s written emission-related instructions.
Chapter 6 Air Emissions 6-

6.5.6.4 Military Training Engines

EPA understood that some engines used in training and testing of milita

personnel may have to be configured similarly to engines used by the U.S. or its

allies in combat operations. Therefore,EPA has exempted stationary ICE en

used for military purposes that meet the national security exemption. In general, you will know the national security exemption applies to an engine when

the engine has a label containing the following information in block letters in 

English

 The label heading of “EMISS

 The engine manufacturer’s corporate name and trademar

 Model year and displacement of the engine or whom to contact for further

information

 The words “TH ENGINE HA

UNDER 40 CFR 89.

Manufacturers may request a national security exemption for any non-road

engine that does not meet the otherwise applicable emissions standards. Any

manufacturer requesting a national security exemption must state the purpose 

for which the exemption is required, and the request must be endorsed by an 

agency of the federal government charged with responsibility for national defense. PA maintains a list of models of non-road engines that have been grant

a national security exemption.

This list is available by writing to the following address

Group Manager, Engine Compliance Programs Gro

Engine Programs and Compliance Division (6403J

Environmental Protection Age

1200 Pennsylvania Ave.,

Washington, DC 20460

Furthermore, engines that receive the national security exemption under the 

non-road engine provisions when purchased will continue to be exempt if used 

as stationary ICE, as long as it continues to be used for national security purposes. In addition, engines that receive a national security exemption will also 

exempt from the low sulfur and ULSD fuel requirements of the regulation

6.6 National Emission Standards for Hazardous 

Air Pollutants

The CAA establishes technology-based emissions standards for HAPs

Congress found, upon exposure, can cause serious adverse health effects. PA 

required to evaluate and control emissions of 187 HAPs, also known as toxic a

pollutants or air toxics. For example, benzene is a AP found in gasoli

There are two types of stationary sources that generate routine emissions of air

toxics:

 Major source is defined as facilities that emit or have the potential to emit 

10 tons per year (tpy) of any of the listed HAPs or 25 tpy of a mixture of 

These sources may release air toxics from equipment leaks when materials

The federal list of HAPs began with a 

list of 189 compounds in 1990, two of 

which have since been deleted. States 

are free to add additional pollutants 

to the list as they see fit.

Did You Know?
6-18 Chapter 6 Air Emissio

are transferred from one location to another, or during discharge through 

emission stacks or vents.

 Area source consists of a smaller size facility that releases fewer quantities of 

HAPs into the air. Area sources are defined as stationary sources of HAP

do not meet the definition of major source. Though emissions from individual

area sources are often relatively small, collectively their emissions can be of 

concern—particularly where large numbers of sources are located in heavily 

populated areas.

TheNESHAP are regulations based on the best demonstrated control tech

or practices within the regulated industries and must include control technology 

requirements, operational controls, and disposal requirements. The standards

are based on the emission levels already achieved by the best performing similar facilities and require installation of emission controls known as Maximum 

Achievable Control Technology (MACT) to meet emission limits. ESH

MACT standards apply to both new and existing emission sources. The regulat

program intends to reduce potential exposures to the identified HA

Many DLA Energy facilities are potentially covered by one or more of sev

NESHAP regulations found in 40 CFR 63, as f

 SubpartA – General Provisi

 SubpartR – Gasoline Distribution Faciliti

 SubpartEEEE – Organic Liquids Distribution (Non-ga

 Subpart ZZZZ – Stationary Reciprocating Internal Combustion En

 Subpart GGGGG – Site Remediat

 Subpart BBBBBB – Gasoline Distribution Bulk Terminals, Bulk Plants, a

Pipeline Facilitie

 Subpart CCCCCC – Gasoline Dispensing Facilitie

Note that there are additionalNESHAP that may apply to your facility. 

regulations and Appendix B for a listing of other common N

Once a permit to operate a fuel facility is issued, applicableNESHAP emi

standards and monitoring, recordkeeping, and reporting requirements become 

part of the permit conditions. The requirements for each of these standards are

summarized in the following sections.

6.6.1 Subpart A – General Provisions

Like the SPS General Provisions,the NESHAP General Provisions contain numerous requirements that are generally applicable to sources s

unless otherwise noted within a specific NESHAP. The types of requir

specified in ESHAP Sbpart A are similar to the types of requirements sp

in SPS Subart A (notification requirements, performance testing requirem

monitoring requirements, recordkeeping and reporting requirements, control 

device requirements). In addition, all major sources of HAPs subject t

are required to develop a written Startup, Shutdown, and Malfunction (SSM

that describes detailed procedures for operating and maintaining the source 

during periods of SSM. The purpose of the plan is to help focus on steps nee
Chapter 6 Air Emissions 6-

to minimize emissions during an SM before such an event occurs. Steps taken

minimize emissions are to be consistent with good air pollution control practices 

and with good safety practices.

6.6.2 Subpart R – Gasoline Distribution Facilities

NESHAP 40 CFR 63 ubpart R defines a gasoline distribution facility as a 

that receives gasoline by pipeline, ship, or barge and that has a gasoline throughput of 20,000 gallons per day (gpd) (75,700 liters per day) or more. SubpartR applies to bulk gasoline terminals and pipeline breakout stations that are majo

sources of AP emissions by themselves, or are located within or adjoining

larger facility that is a major source of AP emissions. For instance, if your termin

does not emit HAPs above the major source thresholds but is part of a military base 

that is a major source of HAPs, then you need to comply with Subpart R requirements. 

If your facility is an area source (not a major source), then it would comply with

NESHAP Subpart BBBBBB mentioned later in this c

If your facility is subject to Subpart R, you are required to install emission contro

or comply with emission limits on gasoline loading racks, storage tanks, and 

equipment. You also need continuous monitoring on loading rack operations. 

These standards mostly mirror theNSPS discussed in Subpart XX, except

certain SubpartR standards are more stringent tha NSPS Subp

In addition, this SubparR NESHAP requires specific work practice s

related to spills and seals on containers be followed.

6.6.3 Subpart EEEE – Organic Liquids Distribution (Nongasoline)

NESHAP Sbpart EEEE contains standards fo reducing HAP emissions at facilities that distribute organic liquids other than gasline. Su

to non-gasoline distribution facilities, such as storage terminals, that are major 

sources of AP emissions by themselves, or are located within or adjoining

larger facility that is a major source of AP emissions and that are not regulat

by another NESHAP. The definition of organic liquid for this subpart specif

excludes gasoline, aviation gasoline, kerosene (No. 1 distillate oil), diesel (No. 

distillate oil), asphalt, and heavier distillate oils and fuel oils. 40 CFR 63 Subpar

EEEE applies to storage and distribution of chemicals, such as natural gas, oxygenates like methyl tert-butyl ether (MTBE), hydrazine, and other missile

If your facility is subject to Subpart EEEE, you are required to comply

emission limits, operating limits, and work practice standards for storage tanks, 

transfer racks, equipment leaks, and some transport vehicles. If your terminal

does not emit HAPs above the major source thresholds but is part of a milita

base that is a major source of HAPs, then you may need to comply with Subp

EEEE. Contact your state or regional air control agency to understand the f

requirements specific to your facility.
6-20 Chapter 6 Air Emissio

6.6.4 Subpart ZZZZ – Stationary Reciprocating Internal 

Combustion Engines

Subpart ZZZZ applies to existing, new, and reconstructed stationary reciprocating internal combustion engines (RICE) that are located at a major source or an

area source of AP emissions. It applies to both CIand SI RICE. Engin

by SPS 40 CFR 60 Subarts IIII (for CI RICE) nd JJJJ (for SI RICE) discussed previously are a subset of the engines covered by this regulatio

ZZZZ) and meet the requirements of Subpart ZZZZ by complying with Subpar

or JJJJ. Stationary RICE use reciprocating motion to convert energy and may

fueled by diesel fuel, gasoline, natural gas, and other types of fuels. Your engine 

is not considered a stationary RICE if it is mobile. Per EPA, this means the 

is not a stationary RICE if it is used to drive motor vehicles, or it is in or on a pie

of equipment that is self-propelled and performs another function (for example, 

lawnmowers, off-highway mobile cranes, and bulldozers). In addition, engines

that are designed to be portable or transportable (that is, have wheels, skids, or 

carrying handles) and do not stay in one location for more than 12 months (or 

shorter if a seasonal source) are not considered to be a stationary RI

The requirements of Subpart ZZZZ applicable to your specific RICE depend

whether they are considered existing or new. Exhibit 6−6 defines new and existing RICE under Subpart ZZZZ. Brake horsepower (bhp) is a specific measurement of an engine’s output before the loss of horsepower caused by any ot

component; it can be thought of as the capacity of the engine. 

EXHIBIT 6−6

Subpart ZZZZ Definition of New and Existing RICE

New or 

Existing Facility Category RICE Size (bhp) Date Constructed or Reconstructed1

New Major source >500 On or after December 19, 2

New Major source ≤500 On or after June 12, 2

New Area source All On or after June 12, 

Existing Major source >500 Before December 19, 20

Existing Major source ≤500 Before June 12, 20

Existing Area source All Before June 12, 2

1

Reconstruction, unless otherwise defined in a relevant standard, means the replacement of components of an 

affected or a previously non-affected source to such an extent that: 

1. The fixed capital cost of the new components exceeds 50 percent of the fixed capital cost that would be 

required to construct a comparable new source; and 

2. It is technologically and economically feasible for the reconstructed source to meet the relevant standard(s) 

established by the Administrator (or a State) pursuant to section 112 of the Act. Upon reconstruction, an 

affected source, or a stationary source that becomes an affected source, is subject to relevant standards 

for new sources, including compliance dates, irrespective of any change in emissions of hazardous air 

pollutants from that source.
Chapter 6 Air Emissions 6-

The following RICE do not have to meet the requirements of Subpart 

 ExistingSI two-stroke lean burn (2SLB) RICE rated at more than 500 bh

major source

 ExistingSI four-stroke lean burn (4SLB) RICE rated at more than 500 bh

major source

 Existing emergency RICE rated at more than 500 bhp at a major so

 Existing limited use RICE rated at more than 500 bhp at a major so

 Existing RICE rated at more than 500 bhp at a major source that combu

landfill or digester gas equivalent to 10% or more of the gross heat input on 

an annual basis

The following RICE are subject to Subpart ZZZZ; however, they meet the requirements of this subpart by meeting the requirement of NSP Subpart 

and no further Subpart ZZZZ requirements apply

 New or reconstructed RICE at an area so

 New or reconstructed 2SLB RICE rated at 500 bhp or less at a major s

 New or reconstructed 4SLB RICE rated at less than 250 bhp at a major s

 New or reconstructedSI four-stroke rich burn (4SRB) RICE rated at 500

less at a major source

 New or reconstructed RICE rated at 500 bhp or less at a major source t

combusts landfill or digester gas equivalent to 10% or more of the gross heat 

input on an annual basis

 New or reconstructed emergency or limited use stationary RICE rated at 

bhp or less at a major source

 New or reconstructed CI RICE rated at 500 bhp or less at a major s

The Subpart ZZZZ requirements vary by the type of engine (that is, SI

four-stroke/two-stroke, rich burn/lean burn), engine use (that is, emergency/

non-emergency, black start/non-black start), engine horsepower, and fuel type 

(diesel, gasoline, natural gas, or if landfill or digester gas is used).  black start

engine is one whose only purpose is to start up a combustion turbine and could 

apply to turbines at military terminals. Emission limits for HAPs are imposed

limiting emissions of either formaldehyde or carbon monoxide (for example, by 

using an oxidation catalyst) and/or by requiring oil and filter changes, air filter 

changes, and inspection and replacements of hoses and belts at specific time 

intervals.

Exhibits 6−7 and 6−8 summarize compliance requirements for existing and new 

engines, respectively. See Appendix 6−1 and 6−2 for more detailed tables with

other requirements such as emission limits, testing, monitoring, and recordkeeping references.
6-22 Chapter 6 Air Emissio

EXHIBIT 6−7

Compliance Requirements for Existing Engines

Existing Engines Compliance Requirements

Group One

All engines <100 hp at major

source

Emergency/black start: ≤500 hp

at major source and all at area 

source

Cl ≤300 hp non-emergency at 

area source

SI ≤500 hp non-emergency a

area source I 2SLB >500 hp nonemergency at area sou

SI LFG/DG >500 hp nonemergency at area sour

SI 4SLB or 4SRB >500 hp nonemergency at area source and

used ≤24 hours/year

 Change oil/filter, inspect air cleaner or spark plugs,

hoses/belts on prescribed schedule or use oil 

analysis program instead of prescribed oil change 

frequency

 Operate/maintain engine and control device pe

manufacturer’s instructions orowner-developed 

maintenance plan

 Emergency engines must have a non-resettable

hour meter and record hours of operation and 

document hours spent in emergency or nonemergency operation; if engines used for demand 

response, keep record of notification of emergency 

situation and time operated

 Keep records of maintenance

 Notifications not required

Group Two

SI 100−500 hp at major sour

SI >500 hp at area source that ar

4SLB or 4SRB and are used >

hours/year

CI ≥100 hp at major sourc

CI >300 hp at area source

(additional requirements)

SI 4SRB >500 hp at major so

 CO and/or formaldehyde limit

 Engines >500 hp: initial and subsequent emission

performance tests

 Engines >500 hp: enhanced monitoring of

emissions control devices

 Notification

 Semiannual compliance report

In addition for CI >300 hp: ultra-low sulfur diesel 

(except rural Alaska) and crankcase emission control

requirements

Exhibit 6−8 

Compliance Requirements for New Engines 

New Engines Compliance Requirements

SI 4SRB >500 hp non-emerge

at majorsource

SI 2SLB >500 hp non-emergen

at majorsource

SI 4SLB >250 hp non-emergen

at majorsource

CI >500 hp non-emergency at major

source

 CO and/or formaldehyde emission limit

Initial and subsequent emission performance test

 Operating limitations − enhanced monitoring of

emissions control devices

 Notifications require

 Semiannual compliance report

Emergency/limited use >500 hp new

at major source Initial notification onl

Non-emergency landfill or digester

gas-fired engine >500 hp new at 

major source

Initial notificatio

 Monitor/record fuel usage dail

 Annual report of fuel usag

The compliance dates are May 3, 2013, for existing CI RICE and October 19,

for existing I RICE. All new RICE subjectto this NESHAP must be

on the day of startup.
Chapter 6 Air Emissions 6-

Contact your state or regional air quality agency to understand the full requirements specific to your facility.

6.6.4.1 Owners and Operators of CI ICE

New CI engines that are subject to 40 CFR Part 60 Subart IIII must 

requirements specified in SubpartIIII to be in compliance with 40 C

Subpart ZZZZ. There are no additional requirements for these engines unde

Subpart ZZZZ

The requirements for existing or reconstructed non-emergency CI ICE vary

engine horsepower and location (area source or major source). The requirements

generally include startup requirements, initial performance tests, compliance 

demonstrations, emission limits, operating limitations, reporting, and recordkeeping. It’s best to operate the engine equipment according to the manufacturer’s instructions. Existing CI engines with a rating of more than 300 bhp must u

ULSD fuel

Refer to Appendix 6−1 for a summary of CI ICE requirements based on the t

and location of engine.

6.6.4.2 Owners and Operators of SI ICE

NewSI engines that are subject to 40 CFR Part 60 Subpart JJJJ must mee

requirements specified in Subpart JJJJ to be in compliance with 40 CFR 63 Subpa

ZZZZ. There are no additional requirements for these engines under Subpart ZZZ

The requirements for existing or reconstructed nonemergencySI ICE var

engine horsepower, type (four-stroke/two-stroke, rich burn/lean burn), and location (area source or major source). The requirements generally include startup

requirements, initial performance tests, compliance demonstrations, emission 

limits, operating limitations, reporting, and recordkeeping.

Refer to Appendix 6−2 for a summary ofSI ICE requirements based on base

the type and location of engine.

6.6.4.3 Emergency Stationary RICE

An emergency RICE is one that is used to provide power in an emerge

situation, such as when electrical power from local utility (or the normal power 

source) is interrupted or the emergency engine is used to pump water in case of 

fire or flood. There are no time limit restrictions on the operating hours during

an emergency situation. An emergency RICE may also be used for up to 

hours per year in specific situations. For instance, an emergency engine may be 

operated for readiness testing and maintenance checks as recommend by the 

manufacturer, insurance company, or governmental emergency agencies. In

addition, an emergency engine may be used for emergency demand response 

programs when an emergency alert is declared or when there is a deviation 

of voltage or frequency of more than 5% below standard voltage or frequency 

(similar to requirements mentioned under SPS 40 CFR 60 Subarts IIII a

There is no limit on the number of hours the engines may operate under these

scenarios, however it must be in compliance with the emission standards and 

other applicable requirements for a nonemergency engine. 

Limited Use versus 

Emergency Use Engines

Limited use engines are used for 

less than 100 hours a year and are 

regulated differently than emergency 

engines. Emergency use engines are 

also limited to 100 hours per year, but 

only 50 of those hours can be used for 

non-emergency purposes.

Did You Know?
6-24 Chapter 6 Air Emissio

New, reconstructed, and existing emergency RICE rated at 500 bhp or less a

major source and all emergency RICE at an area source are subject to Subp

ZZZZ.  new or reconstructed emergency RICE meeting either description m

meet the requirements of Subpart ZZZZ by meeting the requirements of

Subpart IIII, for CI engins or NSPS SubpartJJJJ, for SI engines. Existing emergency RICE have to meet the Subpart ZZZZ work practice standa

RICE as summarized in Exhibit 6

EXHIBIT 6−9

Requirements for Emergency Stationary RICE at Major and Area Sources of HAP 

Emissions

For each... You must meet the following requirements, 

except during periods of startup...

During periods of 

startup you must...

Emergency

CI RICE (

black start 

CI RI

Change oil and filter every 500 hours of 

operation or annually, whichever comes first.2

Inspect air cleaner every 1,000 hours of

operation or annually, whichever comes first, and 

replace as necessary.

Inspect all hoses and belts every 500 hours or

annually, whichever comes first, and replace as 

necessary.3

Minimize the time spent

at idle and minimize 

the time at startup not 

to exceed 30 minutes, 

after which time the 

non-startup emission 

limitations apply.3

Emergency

SI RICE 

black start 

SI 

Change oil and filter every 500 hours of 

operation or annually, whichever comes first.2

Inspect spark plugs every 1,000 hours of

operation or annually whichever comes first, and 

replace as necessary.

Inspect all hoses and belts every 500 hours or

annually, whichever comes first, and replace as 

necessary.3

Minimize the time spent

at idle and minimize 

the time at startup not 

to exceed 30 minutes, 

after which time the 

non-startup emission 

limitations apply.3

Notes

1Comply with the scheduled work practice requirements for an emergency engine when it is safe to 

do so after the engine shuts down if there is an emergency on the scheduled date.

2There is an option to use an oil analysis program in 40 CFR 63.6625 to extend the specified oi

change requirement.

3TheEPA and state or regional air quality agency may be petitioned for alternative work practi

The following types of emergency RICE do not have to meet the requirements

Subpart ZZZZ

 Existing emergency RICE rated at more than 500 bhp at a major source th

does not operate more than 15 hours per year

 Existing residential, commercial, and institutional emergency RICE at an ar

source

Any emergency engine operation other than for emergency situations, maintenance and testing, demand response, and operation in non-emergency situations

for up to 50 hours per year subjects it to the full regulation of Subpart ZZZZ for

non-emergency engines. Emergency engines must be operated and maintained

in accordance with the manufacturer’s emission-related O&M instructions, o

develop and follow your own maintenance plan that must provide to the extent 

practicable for the maintenance and operation of the engine in a manner consistent with good air pollution control practice for minimizing emissions.
Chapter 6 Air Emissions 6-

If you own or operate an existing emergency stationary RICE with a site rating

less than or equal to 500 bhp located at a major source or an existing emergency 

stationary RICE located at an area source, you must install a non-resettable ho

meter if one is not already installed. 

Refer to Appendix 6−1 (CI engines) and Appendix 6−2 (SI engines) for a summ

of monitoring, recordkeeping, and notification requirements for emergency RIC

Consult with your state air quality agency for more details.

6.6.5 Subpart GGGGG Site Remediation

Subpart GGGGG establishes emission limits and work practice standards for

HAPs emitted from site remediation activities or cleanups. For 40 CFR 63 Sub

GGGGG to apply, the media (for example, soil or groundwater) being cleaned 

must be contaminated with organic HAPs. Also, the facility at which the remediation activity is located must be a major sourceof HAP emissions by thems

or be located within or adjoining a larger facility that is a major source of 

emissions and be subject to another MACT standard for other operations at t

facility.

Subpart GGGGG includes emission limits and work practice requirements for

three types of sources:

 Process vent

 Remediation material management unit

 Equipment leak

In addition, Subpart GGGGG includes requirements for control devices used t

comply with the emission standards for process vents and remediation material 

management units. It also requires that remediation material removed from a site

subject to the MACT standard be managed per the regulatory requirements 

off-site disposal facilities, such as landfills; therefore, coordination with the off-site 

facilities is required to ensure full compliance.

If the time required for actual remediation is less than 30 days from initiation of

cleanup (for example, removal of contaminated soil or groundwater) through 

final disposal, the standard does not apply to the cleanup. Cleanups seeking exemption per this 30-day clock must maintain written documentation describing 

the exempted site remediation and listing the initiation and completion dates for 

the site remediation. No request, report, or notification is required to be submitted to qualify for this exemption; however,EPA has specific definitions of w

activities must be conducted within the 30-day period. Contact your state agency 

or consult 40 CFR 63.7884 for specific information

In addition, if you ship or otherwise transfer the remediation material off-site,

you must include in the applicable shipping documentation a statement that 

the shipped material was generated by a site remediation activity subject to the 

conditions of this 30-day exemption. The statement must include the date on

which you began the site remediation activity generating the shipped remediation materials and the date 30 calendar days following your initiation date.
6-26 Chapter 6 Air Emissio

Site remediation activities that result in less than 2,200 lb of HAPs per y

removed are subject solely to recordkeeping requirements.

The rule does not apply to waste materials generated from routine maintenance

activities. Such materials at military fuel facilities might include tank bottoms and

sludges removed during tank cleanouts and/or sludges and sediments removed 

from wastewater treatment tanks, surface impoundments, or lagoons.

Site remediation performed under Comprehensive Environmental Respons

Compensation, and Liability Act (CERCLA) authority, such as the Super

program; under Resource Conservation and Recovery Act (RCRA) authority,

as the corrective action process; or under an EPA-authorized state RCRA pr

are exempted from the regulation. Note that the exemption applies only if the

cleanup is performed under the authority of CERCLA or RCRA. Cleanup pro

performed under state agency voluntary cleanup programs may be required to 

comply with this regulation.

6.6.6 Subpart BBBBBB Gasoline Distribution Bulk Terminals, 

Bulk Plants, and Pipeline Facilities

NESHAP 40 CFR 63 Subpart BBBBBB (sometimes called 6B) establishes e

limitations and management practices for bulk gasoline terminals, pipeline 

breakout stations, pipeline pumping stations, and bulk gasoline plants that 

are area sources of HAPs. An area source is any source that is not a major sou

as defined previously.

Facilities regulated under SubpartR (gasoline distribution at major source facilities) or Subpart CCCCCC (gasoline dispensing facilities) are not subject to BBBBB

Gasoline means any petroleum distillate or blend having an RVP of 27.6 kilopascals or greater, which is used as fuel for internal combustion engine

This regulation requires

 All bulk gasoline facilities must check for leaks and use management

procedures to prevent evaporation of gasoline.

 Bulk gasoline plants, terminals and breakout stations must use submerged fill 

(drop tube) or bottom fill pipes for loading gasoline into storage tanks, tank 

trucks, and railcars.

 Facilities classified as bulk gasoline terminals or breakout stations have 

additional emission control requirements for storage tanks, and larger 

facilities have additional control requirements for loading racks.

Under this rule, bulk gasoline plants with a throughput less than 20,000 gpd are 

subject to less stringent regulatory requirements for storage tanks and loading 

racks than the larger bulk gasoline terminals (greater than 20,000 gpd). Refer to

Appendix 6−3 for an additional summary of facility requirements.

6.6.7 Subpart CCCCCC Gasoline Dispensing Facilities

NESHAP Subpart CCCCCC defines a gasoline dispensing facility (GDF) 

stationary facility that dispenses gasoline into the fuel tank of a motor vehicle, 

motor vehicle engine, non-road vehicle, or non-road engine. This includes facilities that dispense gasoline into on-road and off-road, street, or highway motor
Chapter 6 Air Emissions 6-

vehicles, lawn equipment, boats, test engines, landscaping equipment, generators, pumps, and other gasoline-fueled engines and equipment. Subpart CCCCCC

applies to GDFs located at area sources of HAPs. The loading of aviation gasol

into storage tanks at airports, and the subsequent transfer of aviation gasoline 

within an airport, is not subject to this subpart. If you have two or more GDFs

at separate locations within your area source, each GDF is treated as a separate 

affected source.

If you operate a GDF, you should refer to 40 CFR 63 Subpart CCCCCC and/or contact your state or regional air quality agency to understand the full requiremen

specific to your facility.

6.7 Ozone-depleting Substances

In the early 1970s, scientists first speculated that certain manufactured chemicals, called ozone-depleting substances (ODSs), were destroying the earth’s

stratospheric ozone layer, which protects life and vegetation from damaging 

ultraviolet light. As a result, more than 125 countries signed a landmark treaty

known as the Montreal Protocol in 1987 to limit and subsequently phase out the 

production of all ODSs. In addition, Title VI of the CAA called to limit the emi

of chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), halons, and

other halogenated chemicals that contribute to the destruction of stratospheric 

ozone. PA promulgated the Protection of Stratospheric Ozone regulatio

CFR 82) as a result. Some of the more common ODSs 

 Chlorofluorocarbons such as CFC-11, CFC-12, and CFC-113

 Hydrochlorofluorocarbons such as HCFC-

 Halon such as Halon-1211 and Halon-1

 Carbon tetrachloride

 Methyl chloroform or 1,1,1−Trichloroetha

 Methyl bromid

When the Montreal Protocol was signed, military organizations around the worl

were highly dependent on halons for fire protection and CFCs for air conditioning 

and for manufacturing and maintaining military systems. The U.S. Departmen

of Defense (DoD) has led the way in changing specifications and standards for 

the use of ODSs as solvents in components and products. DoD has worked wit

private industry and PA to identify and verify the acceptability of non-ODS solvents for military uses. DoD established a comprehensive program to reduce

eliminate the use of ODSs in its operations. DoD’s experience in reducing the us

of ODSs at installations and in new and existing weapon systems is an importan

model for implementing pollution prevention (P2)

ODSs are being phased out o

 Refrigerants used in refrigerators and freezer

 Coolants used in air conditioning units, heat pumps, and chillers

 Synthetic foams used in insulation, life vests, and pad

 Propellants used in aerosol spray can
6-28 Chapter 6 Air Emissio

 Cleaning solvents

 Fire suppressants systems and extinguishers

 DoD weapon systems

The U.S. phased out production of all Class I ODSs (such as CFCs) by Decembe

31, 1995. Production and new uses for less harmful Class II ODSs (HCFCs) wer

banned beginning January 1, 2015. HCFCs are to be phased out by 2030. Th

most widely used HCFC is HCFC−22, also referred to as R−22. It is a popu

refrigerant that is commonly used in a variety of refrigeration and air-conditioning equipment. Beginning in 2017, substitute refrigerants, such as HFCs,

hydrofluroolefins (HFOs), and perfluorinated compounds (PFCs) became subje

to the regulatory standards and requirements due to their high global warming 

potential. 

Service and repair of appliances and equipment containing these ODSs and the

substitutes are regulated under federal rules. Technicians performing service

must be certified, and the ODS must be captured, recycled, or destroyed. If y

are at a small fuel terminal, you may want to consider having these services 

performed by a certified outside contractor. 

If you are at a larger terminal and perform this work in-house, you must provide

and document required technician certification. Also required under the 

regulation are the often overlooked requirements to: 

 Document the leak rate and repairs made on equipment containing greater 

than 50 lb of an ODS or ODS substitute,

 Document adequate repairs and leak verification tests when servicing leaking 

equipment, no matter the amount of ODS or ODS substitu

Equipment such as comfort cooling appliances (for example, heating, ventilation and air conditioning [HVAC]) or industrial refrigeration (industrial freezer

chillers, test chambers) have specific leak rate repair requirements that must be 

documented, and leaks must be fixed whenever one is discovered. In general,

you have 30 days from the discovery of a leak to attempt to fix the leak if the unit 

has a single circuit of 50 lb or more of refrigerant. However, do not ignore leaking

units below 50 lb of refrigerant. Once you have knowledge of a leak, you are

required to fix it and perform a follow-up leak verification test to show the leak 

was properly repaired. Reports must be submitted toEPA for chronically leak

appliances (any appliance leaking ≥125% or more of its full charge in 1 year) 

describing the efforts to identify leaks and repair the appliance. The reports are

due no later than March 1 of the following year. You should maintain records onsite of any ODS training, equipment servicing, leak inspections, verification test

reclamation, or disposal for at least 3 years.

6.8 Chemical Accident Prevention Program

The chemical accident prevention program requires facilities that manufacture,

store, or use certain flammable and toxic substances above threshold quantities 

to develop a risk management program if an accident occurs. The program

is about reducing chemical emergency risks and the potential for serious offsite consequences. It requires conducting hazard assessments evaluating the
Chapter 6 Air Emissions 6-

worst-case accidental release scenario. Identifying safety precautions, conducting

training, performing regular maintenance and monitoring, communicating with 

emergency responders, and documenting plans are also to be part of the program in accordance with 40 CFR 68

Refer to Chapter 1, Environmental and Emergency Response Planning for more

information on Risk Management Plan (RMP) requirements. Chapter 12, Ro

Reporting summarizes the MP agency submittal requirements. Also check w

your state agency to see if its rules are more stringent than EPA’s rules. For example, California’s regulations require conducting a seismic stu

Listed flammable substances (such as propane) used as fuel or held for sale as 

fuel at a retail facility are not covered by these regulations. However, flammable

substances used for some other purposes (such as chemical feedstock or when 

held for sale as fuel at a wholesale facility) are covered by these regulations. For 

listed flammable substances, the threshold quantity is 10,000 lb.  commonly

overlooked chemical that is subject to the chemical accident prevention program 

is anhydrous ammonia used in refrigeration units. If your facility uses ammonia

for refrigeration, you need to perform an MP applicability review and may 

required to develop an R

6.9 Air Emissions from Hazardous Wastes

Air emissions from hazardous waste containers, tanks, and process vents are regulated under 40 CFR 265 Subparts AA, BB, and CC (40 CFR 265.1030−1091).

regulations apply to hazardous wastes with a volatile organic (VO) concentration

of 500 parts per million by weight (ppmw) at the point of generation. Gasoline 

and many solvents exceed this VO threshold. The concentration of the VOs 

the waste does not need to be determined analytically; the facility can assume 

that the concentration exceeds the 500 ppmw and implement the requirements. 

Hazardous waste containers (such as drums) with a capacity over 26 gallons must

 Be a U.S. Department of Transportation (DOT)-approved conta

 Operate with no detectable organic emissions or be vapor tigh

 Have covers, lids, and closure devices for each opening that are in place at all

times (except when adding or removing waste)

Open-top containers can be used if they have an organic vapor-suppressing

barrier or foam over the VO material. In addition, containers could be vented to 

control device (such as a combustion unit or flare) or in a building with a closedvent system to a control device. You must maintain records of the inspections and 

the VO concentrations at your facility

These regulations do not apply to containers used for satellite accumulation or to

facilities that are small quantity generators of hazardous waste.

Information on classification, storage, tracking and transport of hazardous waste

may be found in Chapter 7, Hazardous and Recycled Waste.
6-30 Chapter 6 Air Emissio

6.10 Air Permits

All DLA Energy facilities are likely to require air permits from their respective sta

agency or from PA for sources that emit air contaminants (such as storage tan

and vapor recovery systems) and that are not otherwise exempted under state or 

local agency regulations. Generally, there are two types of air permits: construction permits and operating permits. Operating permits can be further classified

as major source operating permits (sometimes called Title V permits) or minor

source operating permits. The process of obtaining an air permit for a new source

of air pollution (such as a storage tank or a new vapor control system) or modifying an existing source of air pollution (reconstructing or installing a floating 

roof on an existing tank) starts with the construction permit. The permit application review process is called new source review or preconstruction review. I

simplified terms, an operating permit is typically issued after the construction 

permit has been issued, the source has been constructed, and conditions of the 

construction permit have been satisfied.

The purpose of the permitting process is to ensure that sources comply with

all state and federal air quality regulations. The following subsections discuss

requirements for Title V operating permits, state minor operating permits, new

source review, and emissions inventory reporting as they apply to DLA Energ

facilities.

6.10.1 Title V Permitting Programs

Title V of the CAA amendments of 1990 requird EPA to develop an oper

permit program for major sources that would be implemented by the state 

air quality agencies. PA promulgated the Title V regulations under 40 CFR

Significant incentives were included in the CAA for the states to develop Titl

programs, so almost all states have. Most states had permitting programs in place

before Title V, and these programs have been modified and retained for minor

sources.

The purpose of Title V is to identify and improve compliance with all applicable requirements of the CAA and to enhance EPA’s ability to enforce

regulations. It’s also a way to ensure accountability through public review and

certification of compliance. Permit holders file periodic reports certifying the

extent of compliance. Title V provides that permits for most sources be issued for

a term not less than 3 years and not more than 5 years. Under Title V, sources are

required to pay annual fees proportional to their amount of air emissions.

Title V applies to major stationary sources of air pollution. Under the Title 

program, a major source is defined as a facility with the potential to emit:

 Over 100 tpy of any criteria pollutant (CO, NOx, SOx, PM,

 Over 10 tpy of any

 Over 25 tpy of total 
Chapter 6 Air Emissions 6-

For sources located in nonattainment areas, major source thresholds can be lower 

than listed above and depend on the level of nonattainment (see Exhibit 6−10). 

State agencies and local air quality offices may establish more stringent thresholds than those shown in Exhibit 6−10. State and local air regulations need to b

checked to ensure the proper threshold is used to determine Title V applicability.

Potential to emit (PTE) is a legally complicated definition of the maximum capacity of the facility to emit air pollutants. Calculating a facilit’s PTE is usually

on 24-hour/day, 365-day/year operation of a source at its maximum operational 

capacity in the absence of air emission controls, if any. ThePTE of a source 

be limited by obtaining federally enforceable limitations on the operation of the 

source, as discussed in the next section, Synthetic Minor Permi

EXHIBIT 6−10

Major Source Pollutant Thresholds for Title V Permit Applicability Based on Severity 

of Nonattainment Designation (All values shown in tpy)

Nonattainment Area NOxa,b CO SO2 PM10 VOCb,d

Extreme 10NA 100c 

Severe 25NA 100c 

Serious 50 50 100 c 70 5

Moderate 100 100c 100c 100c 10

Marginal 100 100c 100c 100c 10

a

Does not apply for any source for which the PA has made a finding, under Section 182(f )(1) or (2)

the CAA, that requirements under Section 182(f ) of the act do not app

b

Thresholds for NOx and VOC apply to ozone nonattainment area designati

c

Federal regulations (40 CFR 70) do not specify a more stringent threshold, so the 100 tpy would

apply by default.

d

Ozone transport regions have thresholds of 50 tpy or less depending on category.

NA=not applicab

When defining the TE for a facility, you also need to consider fugitive emissions. Fugitive emissions are pollutants released to the atmosphere throu

leaks or other unintended or irregular releases and not those emissions that 

could not reasonably pass through a chimney, stack, vent, or other functionally 

equivalent opening. The general rule is to include fugitive emissions if they are

regulated by a federal regulation (NSPS or NESHAP), or are occurring at

facility under the Prevention of Significant Deterioration (PSD) rules discussed 

in Section 6.10.5. Otherwise, fugitive emissions are typically not counted toward a

facility’s P

Since emissions from tanks are affected by throughput and the term maximum

capacity does not lend itself to throughput, the method used to calculate 

should be confirmed with the state agency. The preferred method of estimating

potential emissions would be based on the highest throughput of fuel possible 

for the facility, taking into account maximum anticipated fuel demand (such as 

maximum aircraft operations or maximum vehicular activity).
6-32 Chapter 6 Air Emissio

In 1998,EPA issued furter PTE guidance for specific source categories, inc

gasoline bulk plants. Bulk plants are small, bulk gasoline distribution facilities that 

distribute less than 20,000 gallons of gasoline per day, and that receive gasoline 

by truck rather than by rail or barge. TheEPA guidance is given in the form

operational cutoffs. The minor source guideline for a bulk plant is 20,000 gpd,

which is the basic definition of a bulk plant. That is, if a source owner agrees to

limit the amount of gasoline loaded to no more than 20,000 gpd (the operational 

cutoff), then a source that has 90% or more of VOC emissions coming from bulk

loading and unloading of gasoline is a minor source. PA intends for the states 

incorporate this guidance into their rules and general permits. Contact your state 

or regional air quality agency to understand its specific TE requiremen

One of the objectives of the Title V program is to maintain assurance that majo

sources comply with all applicable air quality regulations at all times. Periodic

compliance reporting and certification requirements are included in Title V

permits for this reason. Reporting frequencies for various parts of the facility’s

operation can be found in your Title V operating permit. Compliance certification

is the responsibility of the facility commander. Significant civil and criminal penalties are defined in Title VII of the CAA for non-compliance, and enforcemen

be initiated by PA or any citizen. One important concept to understand ab

Title V is that it does not add any new emissions standards or limitations—it only

captures major sources (large emitters) into the program.

6.10.2 Synthetic Minor Permits

A synthetic minor source is one that has federally enforceable limitations on its

PTE so that it does not exceed any major source threshold. Federally enforceab

limitations are usually permit conditions or control requirements that effectively 

limit some operational aspect, such as hours of operation or throughput, or 

mandate the use of emission control equipment. Synthetic minor permits allow

such sources to stay out of the Title V program. For DLA Energy facilities, a synthetic minor operating permit may include federally enforceable limitations, su

as limitations on fuel type and throughput volume so that VOC emissions will

remain below Title V major source thresholds. The burdens associated with compliance with a synthetic minor permit may outweigh the advantages associated with

avoiding Title V permitting recordkeeping needed to demonstrate compliance 

with synthetic minor permit conditions may actually be greater than that needed 

for a Title V permit. In addition, the restrictions needed to reduc PTE to less 

major source levels may constrain facility operations to the point that the facility 

mission is compromised. The advantage of synthetic minor permitting must be

evaluated on a facility-by-facility basis.

6.10.3 Minor Source Construction and Operation Permits

Generally, the state or regional agency must be notified prior to construction of any 

new stationary sources of air pollution or modification of any existing sources of air 

pollution (modification means something that will increase emissions or cause the 

emission of new pollutants). Often, the start of construction is defined as the date

that a contract is executed for the construction of the facility, not the date of the 

ground-breaking ceremony. Because the definition of commencement of construction may vary from state to state, make sure you understand this definition before 

Often, the start of construction is 

defined as the date that a contract 

is executed for the construction 

of the facility, not the date of 

the ground-breaking ceremony. 

Because the definition of commencement of construction may 

vary from state to state, make sure 

you understand this definition 

before executing a contract so 

that timely permit applications 

can be submitted.

Did You Know?
Chapter 6 Air Emissions 6-

executing a contract so that timely permit applications can be submitted. Penalties

can be imposed for construction of a source without a permit.

The requirements for obtaining a minor source construction and/or operating

permit vary considerably between agencies. In general, the “construction” permit

allows actual construction of the source, and may allow initial startup. Some

agencies require separate startup authorizations following a compliance test. At

some point, the facility may need to apply for a minor source operating permit. 

The operating permit application may consist of a simple form accompanied by

a source test verifying that the conditions of the construction permit have been 

satisfied. If a separate operating permit for minor sources is required, the need for

an associated application will usually be specified in a construction permit.

Contact your state or regional agency to determine the appropriate permitting 

procedures. In general, you will need to

 Define the proposed scope of the project or modification.

 Estimate the quantity of emissions created by the modification (new

emissions or an increase in emissions).

 Review the state regulations for construction permits and associated permit

exemptions.

 Review the state operating permit requirements

 Determine if construction and/or operating permits are required (new 

permits or modifications to existing permits).

 Complete and submit the appropriate permit applications to the state 

agency.

Many agencies will conduct a completeness review of your application to notify

you if further information is needed for their evaluation of the permit request. If

your application is complete, most agencies will provide the permit to you within 

60 to 90 days. The exact state review period should be factored into your planned

construction schedule.

6.10.4 Major Modification and New Sources in Nonattainment 

Areas

Installation of new major stationary sources or major modifications to existing

major sources in areas designated as nonattainment requires special approval by 

your applicable state or regional agency. These projects require strict emissions

controls and corresponding emissions reductions, or offsets, from other facilities 

located in the region.

For purposes of this program, major source thresholds depend on the severity 

level of the nonattainment designation and are the same as those for Title V permitting as shown in Exhibit 6−10.A major modification is either a modificatio

at an existing minor source with emissions greater than major source thresholds 

or a modification at an existing major source that would result in a significant 

net emission increase. Significant emission rates are defined as follows for each

individual pollutant:
6-34 Chapter 6 Air Emissio

 Particulate matter=15 tp

 Nitrogen oxides=40 tp

 Sulfur dioxide=40 tp

 Carbon monoxide=100 tpy

 VOCs (ozone)=40 tp

 Lead=0.6 tpy

Lower thresholds may apply based on the severity of nonattainment within the 

area in which the project occurs.

The construction of a new source or modification of an existing source, as

described, will trigger the requirement for controls that limit emissions to the 

Lowest Achievable Emission Rate (LAER). LAER is the strictest method 

emissions control technically achievable, and must be at least as strict as any 

NSPS standard. LAER does not take into account economic consideration

DLA Energy facilities, LAER may consist of thermal oxidation of fuel va

6.10.5 Prevention of Significant Deterioration Program

Installation of new major stationary sources or major modifications to existing

major sources in areas designated as attainment for any of the criteria pollutants 

also requires special approval by your applicable state or regional agency. In

attainment areas, the potential to emit very high rates of criteria and several 

other air pollutants (over 250 tpy for non-listed sources and over 100 tpy for listed 

sources) triggers the PSD permitting program. Greenhouse gas (GHG) regulatio

can be triggered for projects if GHG emissions increase by 75,000 tpy as CO2e i

the project is also triggering PSD for another PSD-regulated pollutant. Howe

the same major modification thresholds listed previously in Section 6.10 for

nonattainment new source review also apply to new sources proposed at existing PSD major sources in attainment areas. If your facility is included in the

program, you are required to install Best Available Control Technology (BACT) 

and perform an air quality impact analysis to demonstrate that the source will 

not adversely impact air quality. BACT is similar but less strict than LAER, s

cost is considered in determination of BACT. Unless your facility is part of a large

installation that supports many other missions, this program would probably not 

apply to DLA Energy facilities, and thus is beyond the scope of this guid

6.10.6 Conformity

The federal government is not allowed to support, permit, or provide financial

assistance for any action that would jeopardize the ability of a state to conform to 

the requirements of its state implementation plan (SIP). Each state’sSIP incorporates the federal CAA requirements into state programs, specifies state r

and gives the states authority to issue air permits. The analysis of federal actions

to determine conformity with a IP is required by the National Environment

Policy Act (NEPA). In compliance withNEPA requiremets, EPA prom

40 CFR 93, “Determining Conformity of Federal Actions to State or Feder

Implementation Plans.” This requirement for review of federal actions applies on

to areas in nonattainment or maintenance status for compliance with NAA

and applies only to the pollutants for which the area is not in attainment. Actions
Chapter 6 Air Emissions 6-

must be evaluated in a conformity determination that addresses both direct and 

indirect emissions resulting from the project. Direct emissions are caused by the 

action and occur at the same time and place as the action. Indirect emissions 

are caused by the action later in time and/or are removed from the action but are 

still reasonably foreseeable.

The addition of new fuel storage facilities or the expansion of existing fuel

storage facilities are examples of federal actions that must be evaluated in this 

regard. For example, if your facility is located in an area classified as nonattainment for ozone, any significant changes to facility operations must be evaluated 

to determine if emissions of VOCs would increase beyond certain defined

thresholds. If so, the increase must be consistent with the most recent ozone

approved by E

Your state agency can help determine the conformity applicability thresholds 

and requirements for federal projects in specific areas. If your facility is located in

a nonattainment or maintenance area, estimates of direct and indirect emissions 

increases (or decreases) should be prepared early in the planning process. 

document called a Record of Non-Applicability (RONA) is also to be prepa

part of the conformity applicability evaluation to indicate that a proposed action 

is below the de minimis level (the minimum thresholds for which a conformity 

determination must be performed for criteria pollutants) or otherwise qualifies 

for an exemption in the rule. ONA documentation is most helpful when 

annual emissions are close to the de minimis level or for controversial actions that 

may be challenged.

6.11 Annual Air Emission Inventories

Most state and regional agencies require regular inventories of emissions from

sources of air pollution. If your facility requires a construction permit, minor

source operating permit (including synthetic minor permit), and/or Title V permit,

you will almost always be required to submit an emissions inventory annually 

to your applicable agency. Emissions and license fees associated with the emissions inventory submittals are the primary means by which air pollution control

agencies collect revenue to support their staff.

Many agencies even require reporting of emissions from unpermitted sources.

Unpermitted sources are usually small sources that the state agency has decided 

do not emit enough pollution to justify the expense of including them in the 

permitting program. There are usually types of sources that are exempt from

permitting but not exempt from annual emissions inventory requirements. As a

safeguard, you should expect to report emissions from all fuel storage tanks and 

vapor control systems. Refer to Chapter 12, Routine Reporting for more information on air reporting requirements

Typical emissions estimating tools used to prepare inventories are discussed

in Appendix 6−4. Consult the regulations of your specific agency to determine 

acceptable inventory reporting requirements and methodology.

Emissions testing (measuring the actual concentration of chemicals in emissions)

is typically required for sources subject to numerical emissions limitations. The

500 parts per million by weight 

(ppmw) is equivalent to 0.05 percent.

Did You Know?
6-36 Chapter 6 Air Emissio

purpose of emissions testing is to verify compliance with those limitations. 

Measurements can be obtained by continuous emission monitors or by performing actual stack tests. For example, you are required to conduct annual emissions

testing if your facility has air pollution control devices, such as flares, condensers, or adsorber systems. Emissions tests are not used for license fee (emissions

inventory) determination.

6.12 State Requirements

Contact your state and local air pollution control agency to determine if they 

have air quality programs and permitting requirements that differ from the 

federal program.

 Some states (for example, Oregon) have their own state PSD progra

Similar to the federal PSD program, these programs are designed to preve

degradation of air quality in attainment or unclassifiable areas where existing 

air quality is better than NAAQS. Each state may have different thresh

for determining whether a new source or modification triggers the state PS

program.

 California has some of the most stringent air regulations in the nation. For 

instance, the California Environmental Protection Agency, California 

Resources Board (CARB) established enhanced vapor recovery requiremen

and specifications for standing loss controls for aboveground storage tanks 

(for example, certified tanks and paints, pressure/vacuum vent valves). 

Additionally, CARB has a useful database where you can search and obta

engine vendor certificates: www.arb.ca.gov/msprog/offroad/cert/cert.php.

 In some states, such as California portable engines greater than 50 hp are

required to have permits to operate. In New Jersey, portable engines (use

on-site for less than 90 days a year) may be subject to permitting under a 

general permit (GP−019) depending on the use and size of the engine even

though they are not federally regulated.

State Requirements
Chapter 6 Air Emissions 6-

6.13 For More Information

For Information On... See...

Air Related Agencies

EPA’s Office of Air Quality Pla

and Standards https://www3.epa.gov/airquality

EPA’s Office of Air and Radiation www.epa.gov/aboutepa/about-office-air-andradiati

EPA’s Climate Change website https://www.epa.gov/ar

EPA’s Technology Transfer Ne

Related to Air Pollution Topics www.epa.gov/technical-air-pollution-resou

NSPS Compression Ignition En

and Spark Ignition Engines www.epa.gov/stationary-engi

NESHAP for Reciprocating I

Combustion Engines www.epa.gov/stationary-engine

EPA’s Certificate of Conformity websi

for engines www.epa.gov/importing-vehicles-and-engines

EPA’s website for NESHAPs 4

Subpart R, BBBBBB, and CCCC

www.epa.gov/stationary-sources-air-pollution/

gasoline-distribution-mact-and-gact-nationalemission-standards

EPA’s website with guidance for ar

sources www.epa.gov/ttn/atw/area/arearules.html

Documents and References

RIE NESHAP Sub

Regulation Navigation Tool f

applicability

www.epa.gov/ttn/atw/rice/output/quiz.html

EPA’s Combustion Portal 

combustion-related air quality 

regulations

www.combustionportal.org

8-hour Ozone Nonattainmen

Designations by State and County,

Interactive M

www.epa.gov/ozone-pollution

For More Information
6-38 Chapter 6 Air Emissio

6.14 Action Items

Item Date 

Started

Date 

Completed NA Comment(s)

Identify air emission sources from your 

storage tanks (the vents), loading and 

unloading racks, and vapor control 

equipment.



Get assistance if you are unsure which 

air quality regulations apply to your 

terminal.



Prepare and submit emissions 

inventory reports and license fees 

to your state or regional air quality 

agency.



Visually inspect the primary and 

secondary seals and take gap 

measurements as appropriate on your 

tanks storing petroleum or volatile 

organic liquids.



Maintain records on the type of 

fuel stored, the period of storage, 

throughput, and maximum true 

vapor pressure of the liquid stored. 

Keep records of fuel burning engines, 

pumps, and generators with installation 

dates, manufacturer model numbers, 

conformity determinations, operational/

run time data, and O&M manuals. Kee

these records for a minimum of 5 years.



Determine whether your facility is in an 

attainment or nonattainment area for 

ozone or VOCs prior to construction

of a new source or modification of 

existing sources resulting in increased 

emissions.



Contact your state or regional agency 

for help in evaluating whether the 

addition of new fuel storage tanks or 

the expansion of existing facilities will 

conform with the state’s S



Notify the air quality agency and obtain 

a construction permit before adding 

or modifying additional tanks, loading 

racks, and other sources that would 

increase emissions. (Some construction

activities may be exempt from 

permitting.)



Obtain operating permits (or modify 

your Title V permit if you are a

major source) for construction or 

modification of existing sources that 

will increase emissions.



Review the specific monitoring, recordkeeping, and reporting requirements in 

your facility’s air permit.



Action Items
Chapter 6 Air Emissions 6-

Appendix 6−1 Summary of Compression Ignition Stationary 

 Reciprocating Internal Combustion Engine

 Requirements (40 CFR 63 Subpart ZZZZ)

Appendix 6−2 Summary of Spark Ignition Stationary Reciprocating

 Internal Combustion Engine Requirements

 (40 CFR 63 Subpart ZZZZ)

Appendix 6−3 National Air Toxic Standards for Gasoline Distribution 

 Bulk Terminals, Bulk Plants, and Pipeline Facilities 

 (40 CFR 63 Subpart BBBBBB)

Appendix 6−4 Tools for Estimating Emissions

CHAPTER 6 

Appendices
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Chapter 6 Air Emissions 6-

Appendix 6-1: Summary of Compression Ignition Stationary Reciprocating Internal Combustion Engine Requirements (40 CFR 63 Subpart ZZZZ)

Source Type [§63.6585; 

63.6590]

Engine Type Emission Standards (Limits)1

[§63.6602; Subpart ZZZZ Table 2c] Work Practice Standards1

Tests [§63.6610, 63.6612,

63.6615, 63.6620] Monitor [§63.6625,

63.6635, 63.6640]

Records [§63.6655; 63.6660] Notifications 

[§63.6645] Site Rating Specific Engine Carbon Monoxide (CO)

@ 15% O2

Sulfur Oil and Filter Air Cleaner Hoses and Belts (Initial Performance Test within 180 

Days After Compliance Date)

(Copies of Notifications If 

Required)

Major Existing >500 hp Non-emergenc

Non-black star

23 ppmvd or reduce C

by 70% 15 ppm Initial Performance and Retest Subpart ZZZZ Table 3, 4, and 

Temperature and

Pressur

Malfunctions, performanc

tests/evaluations, maintenance

on OC/CC/CMS, notification

and continuous monitoring

Yes

Major Existing >300 hp a

<500 hp

Non-emergency,

Non-black star

49 ppmvd or reduce C

by 70% 15 ppm Initial Performance (See SubZZZZ Table 4 and 5

Malfunctions, performanc

tests/evaluations, maintenance

on OC/CC/CMS, notification

and continuous monitoring

Yes

Major Existing >100 hp a

≤300 hp

Non-emergency,

Non-black start 230 ppmvd Initial Performance (See SuZZZZ Table 4 and 5

Malfunctions, performanc

tests/evaluations, maintenance

on OC/CC/CMS, notification

and continuous monitoring

Yes

Major Existing <100 hp Non-emergency 

Non-black star

Change every 1,000 

hrs or annually, 

whichever occurs 

first2 (See Subpar

ZZZZ Table 2c

Inspect every 1,000

hrs or annually,

whichever occurs 

first (See Subpa

ZZZZ Table 2c

Inspect every 500

hrs or annually,

whichever occurs 

first (See Subpa

ZZZZ Table 2c

Maintenance Plan (See §63.6

and Subpart ZZZZ Table 

Maintenance and malfunction

records N

Major Existing >500 hp Limited use No Requirem

Major Existing >500 hp Emergency, bl

start3 No other requirements except §63.6640(f )(2)(ii)−(iii

Major Existing ≤500 hp Emergency, bl

start3

Change every 500 

hrs or annually,

whichever occurs 

first2 (See Subpa

ZZZZ Table 2c

Inspect every 1,000

hrs or annually,

whichever occurs 

first (See Subpa

ZZZZ Table 2c

Inspect every 500

hrs or annually,

whichever occurs 

first (See Subpa

ZZZZ Table 2c

Maintenance Plan (See §63.6

and Subpart ZZZZ Table 

Non-resettable hour

meter

Hours of operation, reason fo

operation, maintenance, and 

malfunctions

N

Major New 

Reconstructed >500 hp Non-emergencyNon-black star

Reduce CO by 70% (S

Subpart ZZZZ Table 2a

or limit formaldehyde 

conc. to 580 ppbvd

Initial Performance and Retest 

Subpart ZZZZ Table 3, 4, and 

Temperature and

pressure

Malfunctions, performanc

tests/evaluations, maintenance

on OC/CC/CMS, notification

and continuous monitoring

Yes

Major New 

Reconstructed >500 hp Emergency3 No other requirements except §63.6640(f )(2)(ii)−(iii) 

Major New 

Reconstructed >500 hp Limited use No other requirements except Initial Notification

Major New 

Reconstructed <500 hp Must comply wit NSPS 40 CFR 60 S

Area Existing >500 hp Non-emergenc

Non-black star

23 ppmvd or reduce C

by 70% (See Subpar

ZZZZ Table 2d

Initial Performance (See Sub

ZZZZ Table 4 and 5

Temperature and

Pressure; must install

closed ccvs or ocfecs

Malfunctions, performanc

tests/evaluations, maintenance

on OC/CC/CMS, notification

and continuous monitoring

Yes
6-42 Chapter 6 Air Emissio

Source Type [§63.6585; 

63.6590]

Engine Type Emission Standards (Limits)1

[§63.6602; Subpart ZZZZ Table 2c] Work Practice Standards1

Tests [§63.6610, 63.6612,

63.6615, 63.6620] Monitor [§63.6625,

63.6635, 63.6640]

Records [§63.6655; 63.6660] Notifications 

[§63.6645] Site Rating Specific Engine Carbon Monoxide (CO)

@ 15% O2

Sulfur Oil and Filter Air Cleaner Hoses and Belts (Initial Performance Test within 180 

Days After Compliance Date)

(Copies of Notifications If 

Required)

Area Existing >300 hp a

≤500 hp

Non-emergency,

Non-black star

49 ppmvd or reduce C

by 70% (See Subpar

ZZZZ, Table 2d

Initial Performance (See Sub

ZZZZ Table 4 and 5

Must install closed

ccvs or ocfecs

Malfunctions, performanc

tests/evaluations, maintenance

on OC/CC/CMS, notification

and continuous monitoring

Yes

Area Existing ≤300 hp Non-emergenc

Non-black star

Change every 1,000 

hrs or annually, 

whichever occurs 

first2 (See Subpar

ZZZZ Table 2d

Inspect every 1,000

hrs or annually,

whichever occurs 

first (See Subpa

ZZZZ Table 2d

Inspect every 500

hrs or annually,

whichever occurs 

first (See Subpa

ZZZZ Table 2d

Maintenance Plan (See §63.6

and Subpart ZZZZ Table 

Maintenance and malfunction

records N

Area Existing Emergency, bl

start3

500 hrs or annually,

whichever occurs 

first2 (See Subpa

ZZZZ Table 2d

Inspect every 1,00

hrs or annually,

whichever occurs 

first (See Subpa

ZZZZ Table 2d

Inspect every 500

hrs or annually,

whichever occurs 

first (See Subpa

ZZZZ Table 2d

Maintenance Plan (See §63.6

and Subpart ZZZZ Table 

Non-resettable hour

meter

Hours of operation, reason fo

operation, maintenance, and 

malfunctions

N

Area Existi

Emergency

− residential,

commercial, or

institutional3

No other requirements except §63.6640(f )(2)(ii)−(iii

Are

New o

Reconstructed Must comply wit NSPS 40 CFR 60 S

Notes:

*SeeNESHAP Subpart ZZZZ for additional provisions. Appendix 6−1 does not include requirements for engines located on the Outer Continental Shelf (OCS), engines located in remote areas, and engines located in states where periodic engine replacement

1For all engines, the time spent at idle and time for startup must be minimized to not more than 30 minutes. For non−emergency, non−black start engines with a site rating of more than 300 hp and with a displacement of less than 30 liters per cylinder, you must use diesel fuel that

meets the specific requirements in 40 CFR 80.510(b). [§63.6604]

2Option to use an oil analysis program to extend the specified oil change requirement. The oil analysis must be performed at the same frequency as oil changes are required, and the program must analyze the parameters and keep records as required in §63.6625(i

3Emergency engines may not be operated for non-emergency purposes for more than 100 hours per year. Additional restrictions on non-emergency use of emergency engines applies, see Section 63.6640(f) f NESHAP Subpart ZZZZ for specifics. No limit on hours of 

during an emergency. New and existing emergency engines located at major sources of HAPs and greater than 500 hp may not operate for more than 15 hrs/yr for non-emergency purposes as identified in § 63.6640(f )(2)(ii) and (i

4As a major or area source considered new/reconstructed, your requirements under the Subpart ZZZZ are to comply with th NSPS IIII. However, the owners and operators subjt to the NSPS IIII are only CI engines constructed after July 11, 2005, and the engine 

or after April 1, 2006

CC=catalytic controls 

CMS=continuous monitoring syst

ccvs=crankcase ventilation system

hrs=hours

OC=oxidation catalys

ocfecs=open crankcase filtration emission control system

ppbvd= parts per billion of volume dry

ppmvd=parts per million of volume dry

Work Practice Standards − refers to best management practices required

Tests − various tests required depending on your engine

Monitor − requirements regarding monitoring of engine

Records − all records that you are required to maintain

Notifications − provided to PA and/or your state regulatory age
Chapter 6 Air Emissions 6-

Appendix 6-2: Summary of Spark Ignition Stationary Reciprocating Internal Combustion Engine Requirements (40 CFR 63 Subpart ZZZZ)

Source Type1

[§63.6585; 63.6590]

Engine Type Emission Standards (Limits)

[§63.6602; Subpart ZZZZ Table 2c] Work Practice Standards Tests [§63.6610, 63.6612, 63.6615, 63.6620] Monitor 

[§63.6625,

63.6635, 

63.6640]

Records [§63.6655; 63.6660]

Notifications 

[§63.6645] Site 

Rating Specific Engine Carbon monoxide (CO)

@ 15% O2 Sulfur Oil and Filter Spark Plugs Hoses and Belts (Initial Performance Test within 180 

Days After Compliance Date)

(Copies of Notifications If 

Required)

Major Existing >500 

4−stroke rich burn 

Nonemergency

Non−black star

Reduce formaldehyde

by 76% or limit 

formaldehyde conc. to 

350 ppbvd or less (See

63.6600, Subpart ZZZZ

Table 1a

Initial Performance and Retest 

Subpart ZZZZ Table 3, 4, 

Temperature

and Pressur

Malfunctions, performance tests

evaluations, maintenance on 

OC/CC/CMS, notifications, a

continuous monitoring

Yes

Major Existing >500 hp 2− and 4−stroke lea

burn No Requiremen

Major Existing <100 

Nonemergency,

Non−black start, and

not 2−stroke lean 

burn

Change every 1,440

hrs or annually,

whichever occurs first2

(See Subpart ZZZ

Table 2c

Inspect every 1,440

hrs or annually,

whichever occurs 

first (See Subpa

ZZZZ Table 2c

Inspect every 1,440

hrs or annually,

whichever occurs first

(See Subpart ZZZ

Table 2c

Maintenance Plan (See §63.6640 a

Subpart ZZZZ Table 

Maintenance and Malfunctio

Records 

Major Existing <100 

2−stroke lean burn 

Nonemergency

Non−black star

Change every 4,320 

hrs or annually, 

whichever occurs first2

(See Subpart ZZZ

Table 2c

Inspect every 4,320

hrs or annually,

whichever occurs 

first (See Subpa

ZZZZ Table 2c

Inspect every 4,320

hrs or annually,

whichever occurs first

(See Subpart ZZZ

Table 2c

Maintenance Plan (See §63.6640 a

Subpart ZZZZ Table 

Maintenance and Malfunctio

Records 

Major Existi

>100 hp 

and <500 

hp

2−stroke lean burn,

Nonemergency

non−black start

225 ppmvd Initial Performance (See Subpart Z

Table 4 and 5

Malfunctions, performance tests

evaluations, maintenance on 

OC/CC/CMS, notifications, a

continuous monitoring

Yes

Major Existi

>100 hp 

and <500 

hp

4−stroke lean burn,

Nonemergency

non−black start

47 ppmvd Initial Performance (See Subpart Z

Table 4 and 5

Malfunctions, performance tests

evaluations, maintenance on 

OC/CC/CMS, notifications, a

continuous monitoring

Yes

Major Existi

>100 hp 

and <500 

hp

4−stroke rich burn,

Nonemergency

non−black start

10.3 ppmvd 

Formaldehyde3

Initial Performance (See Subpart Z

Table 4 and 5

Malfunctions, performance tests

evaluations, maintenance on 

OC/CC/CMS, notifications, a

continuous monitoring

Yes

Major Existing >500 hp Limited use No Requirem

Major Existing >500 hp Emergency, bl

start4 No other requirements except §63.6640(f )(2)(ii)−(iii

Major Existing ≤500 hp Emergency, bl

start4

Change every 500 hrs 

or annually, whichever

occurs first3 (Se

Subpart ZZZZ Tabl

2c)

Inspect every 1,00

hrs or annually,

whichever occurs 

first (See Subpa

ZZZZ Table 2c

Inspect every 500

hrs or annually,

whichever occurs first 

(See Subpart ZZZ

Table 2c

Maintenance Plan (See §63.6640 a

Subpart ZZZZ Table 

Non

resettable 

hour meter

Hours of operation, reason fo

operation, maintenance, and 

malfunctions

N

Major New 

Reconstructed >500 h

Nonemergency

Non−black start 4

stroke rich burn

Reduce formaldehyd

by 76% or limit

formaldehyde conc. 

to 350 ppbvd3 (See

§63.600(b), Subpar

ZZZZ Table 1a

Initial Performance and Retest 

Subpart ZZZZ Table 3, 4, and 

Temperature

and Pressur

Malfunctions, performance tests

evaluations, maintenance on 

OC/CC/CMS, notifications, a

continuous monitoring

Yes
6-44 Chapter 6 Air Emissio

Source Type1

[§63.6585; 63.6590]

Engine Type Emission Standards (Limits)

[§63.6602; Subpart ZZZZ Table 2c] Work Practice Standards Tests [§63.6610, 63.6612, 63.6615, 63.6620] Monitor 

[§63.6625,

63.6635, 

63.6640]

Records [§63.6655; 63.6660]

Notifications 

[§63.6645] Site 

Rating Specific Engine Carbon monoxide (CO)

@ 15% O2 Sulfur Oil and Filter Spark Plugs Hoses and Belts (Initial Performance Test within 180 

Days After Compliance Date)

(Copies of Notifications If 

Required)

Major New 

Reconstructed >500 h

Non-emergency

Non-black start

2-stroke lean burn

12 ppmvd 

formaldehyde or

reduce CO by 58% (Se

§63.600, Subpart ZZZZ

Table 2a

Initial Performance and Retest 

Subpart ZZZZ Table 3, 4, and 

Temperature

and Pressur

Malfunctions, performance tests

evaluations, maintenance on 

OC/CC/CMS, notifications, a

continuous monitoring

Major New 

Reconstructed >250 h

Non-emergency

Non-black start

4-stroke lean burn

14 ppmvd 

formaldehyde or

reduce CO by 93% (Se

§63.600, Subpart ZZZZ

Table 2a

Initial Performance and Retest 

Subpart ZZZZ Table 3, 4, and 

Temperature

and Pressur

Malfunctions, performance tests

evaluations, maintenance on 

OC/CC/CMS, notifications, a

continuous monitoring

Major New 

Reconstructed >500 hp Emergency4 Se  §63.6640(f)(2)(ii)−(iii) 

Major New 

Reconstructed >500 hp Limited use No requirements other than Initial Notification

Major New 

Reconstructed ≤500 hp Emergency limited use Must comply withNSPS 40 CFR 60 Subpar

Major New 

Reconstructed ≤500 hp 2-stroke lean burn Must comply wit NSPS 40 CFR 60 Subpa

Major New 

Reconstructed <250 hp 4-stroke lean burn Must comply wit NSPS 40 CFR 60 Subpa

Major New 

Reconstructed ≤500 hp 4-stroke rich burn Must comply wit NSPS 40 CFR 60 Subpa

Area Existing >500 

4-stroke lean burn 

Non-emergency

Non-black star

(operates less than 

24 hrs/year)

Change every 500 hrs 

or annually, whichever 

occurs first2 (See

Subpart ZZZZ Tabl

2d)

Inspect every 1,000

hrs or annually,

whichever occurs 

first (See Subpa

ZZZZ Table 2d

Inspect every 500

hrs or annually,

whichever occurs first

(See Subpart ZZZ

Table 2d

Maintenance Plan (See §63.6640 a

Subpart ZZZZ Table 

Maintenance and malfunction

records N

Area Existing >500 

4-stroke rich burn 

Non-emergency

Non-black star

(operates less than 

24 hrs/year)

Change every 500 hrs 

or annually, whichever 

occurs first3 (See

Subpart ZZZZ Tabl

2d)

Inspect every 1,000

hrs or annually,

whichever occurs 

first (See Subpa

ZZZZ Table 2d

Inspect every 500

hrs or annually,

whichever occurs first

(See Subpart ZZZ

Table 2d

Maintenance Plan (See §63.6640 a

Subpart ZZZZ Table 

Maintenance and malfunction

records N

Area Existing >500 

4-stroke rich burn 

not remote, nonemergency, nonblack start (operates 

more than 24 hrs/

year)

Install NSCR to re

HAP emissions (

§63.6603 and Subpar

ZZZZ Table 2d

Initial Performance and Retest 

Subpart ZZZZ Table 3, 4, 

Temperature

and Pressur

Malfunctions, performance tests

evaluations, maintenance on 

OC/CC/CMS, notifications, a

continuous monitoring

Yes

Area Existing >500 

4-stroke rich burn 

remote, nonemergency, nonblack start

Change every 2,160 

hrs or annually, 

whichever occurs first2

(See Subpart ZZZ

Table 2d

Inspect every 2,160

hrs or annually,

whichever occurs 

first (See Subpa

ZZZZ Table 2d

Inspect every 2,160

hrs or annually,

whichever occurs first

(See Subpart ZZZ

Table 2d

Maintenance Plan (See §63.6640 a

Subpart ZZZZ Table 

Maintenance and malfunction

records N

Area Existing >500 

4-stroke lean burn 

not remote, nonemergency, nonblack start (operates 

more than 24 hrs/

year)

Install an oxidation

catalyst to reduce 

HAP emissions (

§63.6603 and Subpar

ZZZZ Table 2d

Initial Performance and Retest 

Subpart ZZZZ Table 3, 4, 

Temperature

and Pressur

Malfunctions, performance tests

evaluations, maintenance on 

OC/CC/CMS, notifications, a

continuous monitoring

Yes
Chapter 6 Air Emissions 6-

Source Type1

[§63.6585; 63.6590]

Engine Type Emission Standards (Limits)

[§63.6602; Subpart ZZZZ Table 2c] Work Practice Standards Tests [§63.6610, 63.6612, 63.6615, 63.6620] Monitor 

[§63.6625,

63.6635, 

63.6640]

Records [§63.6655; 63.6660]

Notifications 

[§63.6645] Site 

Rating Specific Engine Carbon monoxide (CO)

@ 15% O2 Sulfur Oil and Filter Spark Plugs Hoses and Belts (Initial Performance Test within 180 

Days After Compliance Date)

(Copies of Notifications If 

Required)

Area Existing >500 

4-stroke lean burn 

remote nonemergency, nonblack start

Change every 2,160 

hrs or annually, 

whichever occurs first2

(See Subpart ZZZ

Table 2d

Inspect every 2,160

hrs or annually,

whichever occurs 

first (See Subpa

ZZZZ Table 2d

Inspect every 2,160

hrs or annually,

whichever occurs first

(See Subpart ZZZ

Table 2d

Maintenance Plan (See §63.6640 a

Subpart ZZZZ Table 

Maintenance and malfunction

records N

Area Existing ≤500 

4-stroke rich burn 

Non-emergency

Non-black star

Change every 1,440 

hrs or annually, 

whichever occurs first3

(See Subpart ZZZ

Table 2d

Inspect every 1,440

hrs or annually,

whichever occurs 

first (See Subpa

ZZZZ Table 2d

Inspect every 1,440

hrs or annually,

whichever occurs first

(See Subpart ZZZ

Table 2d

Maintenance Plan (See §63.6640 a

Subpart ZZZZ Table 

Maintenance and malfunction

records N

Area Existing Any si

engine

2-stroke lean burn 

Non-emergency

Non-black star

Change every 4,320 

hrs or annually, 

whichever occurs first2

(See Subpart ZZZ

Table 2d

Inspect every 4,320

hrs or annually,

whichever occurs 

first (See Subpa

ZZZZ Table 2d

Inspect every 4,320

hrs or annually,

whichever occurs first

(See Subpart ZZZ

Table 2d

Maintenance Plan (See §63.6640 a

Subpart ZZZZ Table 

Maintenance and malfunction

records N

Area Existing Any si

engine

Emergency, blac

start4

Change every 500 hrs 

or annually, whichever 

occurs first2 (See

Subpart ZZZZ Tabl

2d)

Inspect every 1,000

hrs or annually,

whichever occurs 

first (See Subpa

ZZZZ Table 2d

Inspect every 500

hrs or annually,

whichever occurs first

(See Subpart ZZZ

Table 2d

Maintenance Plan (See §63.6640 a

Subpart ZZZZ Table 

Non

resettable 

hour meter

Hours of operation, reason fo

operation, maintenance, and 

malfunctions

N

Area Existi

Emergency

− residential,

commercial, or

institutional4

No other requirements except §63.6640(f )(2)(ii)−(iii

Are

New o

Reconstructe

(§63.6603)

Must comply withNSPS 40 CFR 60 Subpar

Notes:

*For all engines, the time spent at idle and time for startup must be minimized to not more than 30 minutes. SeeNESHAP Subpart ZZZZ for additional provisions. This Appendix 6−2 does not include requirements for engines located on the Outer Continental Shelf (OCS), engin

remote areas, and engines located in states where periodic engine replacement is required.

1Engines powered by landfill or digester gas are not included in Appendix 6−2; se NESHAP Subpart ZZZZ for applicable requirements for engines using the

2Option to use an oil analysis program to extend the specified oil change requirement. The oil analysis must be performed at the same frequency as oil changes are required, and the program must analyze the parameters and keep records as required in §63.6625(i

3Engine type does not have an option to control carbon monoxide

4Emergency engines may not be operated for non-emergency purposes for more than 100 hours per year. Additional restrictions on nonemergency use of emergency engines applies, see Section 63.6640(f) f NESHAP Subpart ZZZZ for specifics. No limit on hours of operations

emergency. New and existing emergency engines located at major sources of HAPs and greater than 500 hp may not operate for more than 15 hrs/yr for non-emergency purposes as identified in § 63.6640(f )(2)(ii) and (i

5As a major or area source considered new/reconstructed, your requirements under the Subpart ZZZZ are to comply with th NSPS JJJJ see NSPS Subpart JJJJ to determine appl

ppbvd=parts per billion of volume dry

ppmvd=parts per million of volume dry

OC=oxidation catalys

CC= catalytic controls

 CMS=continuous monitoring syste

Work Practice Standards − refers to best management practices required

Tests − various tests required depending on your engine

Monitor − requirements regarding monitoring of engine Records − all records that you are required to maintain

Notifications − provided to USEPA and/or your state regulatory ag
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Chapter 6 Air Emissions 6-

Appendix 6-3: National Air Toxic Standards for Gasoline Distribution 

Bulk Terminals, Bulk Plants, and Pipeline Facilities (40 CFR 63 Subpart 

BBBBBB)1

Facility Type Storage Tanks Cargo Tank Loading Racks Equipment Leaks

Bulk Gasoline 

Plant (less than 

20,000 gallons 

per day)

For storage tanks ≥250 gallons capacity, load storage 

tank using submerged fill with discharge that is no 

more than the following from the bottom of tank:

a) 12 inches for pipes installed on or before 

11/9/2006

b) 6 inches for pipes installed after 11/9/2006

OR keep documentation that the liquid level neve

falls below the pipe discharge.

Use submerged fill

Same for all facilities

Implement monthl

equipment leak

inspection; standards 

allow a sight, sound,

and smell inspection 

of all equipment 

components in 

gasoline liquid or 

vapor service.

Bulk Gasoline 

Terminal

(greater than or 

equal to 20,000 

gallons per day)

≥75 cubic meters (m3) capacity: Use specified 

floating roofs and seals or a closed vent system and 

control device to reduce emissions by 95%.

Gasoline throughput 

<250,000 gallons per day: 

use submerged fill for the 

loading of cargo tanks.

<75 m3 capacity OR <151 m3 capacity and

throughput <480 gallons/day: Cover tank with 

a fixed roof mounted in a stationary manner and 

maintain all openings in a closed position at all times 

when not in use.

Gasoline throughput 

≥250,000 gallons per day: 

(1) reduce AP emissions 

80 milligrams (mg) or less, 

per liter of gasoline loaded 

into cargo tanks and (2) limit 

the loading of gasoline into 

cargo tanks demonstrated 

to be vapor tight2using 

Reference Method 27 

equivalent.

Surge control tank: Cover tank with a fixed roof 

mounted in a stationary manner and with a p/v vent 

with a positive cracking pressure of no less than 0.50 

inches of water. Maintain all openings in a close

position at all times when not in use.

Pipeline 

Breakout Station Same as bulk gasoline terminals Not Applica

Pipeline 

Pumping Station Not Applicable Not Applic

1This is a summary table; compliance will only be determined by compliance with actual rule text in 40 CFR 63 Subpart BBBB

2Must be tested annually and meet a maximum allowable pressure/vacuum change of 3 inches of water in 5 minutes

Source: U.S EPA Office of Air Quality Planning and Standards (EI: 43−02), January 2011. www.epa.gov/ttn/atw/area/are
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Chapter 6 Air Emissions 6-

Appendix 6-4: Tools for Estimating Emissions

Air emission reports, sometimes called emissions inventories, for sources of air pollution are required by most state

and regional air programs. Construction permits, minor source operating permits (including synthetic minor permits), and Title V permits almost always have requirements for annual submittal of emissions inventories to the state

agencies. This appendix describes some of the data needed to prepare emissions inventories. In addition, a brie

overview of emissions estimating techniques is presented.

Data Needed to Estimate Emissions

The following paragraphs provide a quick reference to the types of data that should be collected for estimating

emissions from tanks, loading racks, and combustion sources to prepare emissions inventories. It is not intended as

a complete reference. You will need to understand the emissions estimating techniques to be used to ensure that all 

required data are collected.

Tank Emissions

The method of operation and the physical characteristics of the tank will influence volatile organic compound (VOC

emissions from it. The most important operating parameters are the tank throughput and the volatility of the liquid

stored. Tank throughput can be measured either by the total fuel pumped into or out of a tank. With a large tank,

and where the tank level is significantly higher or lower at the end of the time period versus the beginning, these 

two values may be different. In this case, the total fuel pumped into the tank is the preferred data point. Volatility

of the liquid stored is a function of storage temperature, as indicated by its true vapor pressure. Petroleum liquid

Reid vapor pressures can be converted to true vapor pressures over a range of storage temperatures. Actual dat

from the fuel supplier or Safety Data Sheet (SDS) is useful, although there are average values available in vari

references.

Important physical tank characteristics include the type of roof (fixed or floating), the type of primary and secondary

seals, the numbers and types of roof fittings, the number of vents, the color and age of the tank, and the condition 

of the paint. Other information such as the condition of floating-roof seals, influent nozzle arrangement (splash or

submerged fill pipe), and dimensions of the tank are also used to calculate emissions.

Loading Rack Throughput

The primary data needed to estimate emissions are the amount of fuel loaded onto trucks. Also, data on the truck

themselves, such as splash or submerged filling, dimensions, vent relief settings, and type of vapor collection and 

control system installed, are important. Bulk gasoline terminals are required to comply with emissions limitations. 

The volume of vapors discharged through a vapor control device can be multiplied by the emissions limitation or by

the device control efficiency to obtain an estimate of emissions.

Combustion Sources

For boilers, heaters, and engines, the most important data are the total quantity and type of fuel consumed. For 

liquid fuels, sulfur content is also important. Data on the combustion unit itself includes the heat input rating (British 

thermal unit per hour [Btu/hour] of the burners, manufacturer-provided emissions data, age of the boiler engine, 

and emission control technology installed, if any).

Estimating Methods and Tools

There are several methods available for estimating emissions from pollutant sources: direct measurement, engineering calculations with knowledge of the process generating the pollutant, and emission factors

Direct Measurement

Direct measurement or source testing is the most reliable and the most expensive method of determining emissions 

from a source. Direct measurement is based on actual monitoring of the concentration of a chemical in the exhaust 
6-50 Chapter 6 Air Emissio

stream. Measurements can be obtained by using continuous emission monitors or by performing actual stack tests.

Obtaining test data is not always feasible and may not reflect the variability of actual emissions over time

Engineering Calculations

Knowledge of the process generating the pollutant can be used to estimate emissions, and in many cases, this 

method is as reliable as direct measurement. Typically, these methods are based on standard engineering principals

using properties of the chemicals involved, process data, or process knowledge. For example, VOC emissions from

a paint booth can accurately be assumed to be equivalent to the VOC content of the paint. Obtaining proces

information necessary to use this approach may require some effort, but it is relatively inexpensive in comparison to 

direct measurement.

Mass balancing is a common engineering method of estimating emissions that is widely accepted by state agencies. Chemical engineers have long used mass balances in working with chemical processes. The concept is simple

in theory: for a continuous flow, batch, or semi-batch process, the total inputs to the process must equal the total 

outputs plus any accumulation. The primary limitation of mass balances is the accuracy with which the inputs and

outputs can be measured.

For example, SOx emissions from a boiler can be calculated by mass balance. Since no sulfur accumulates inside

boiler, the total sulfur flowing into the boiler must equal the total sulfur exiting the boiler. By estimating the rate 

of sulfur entering with the fuel and by multiplying by the ratio of molecular weight of SO2 to molecular weigh

of elemental sulfur, the total SO2 per time exiting the boiler can be calculated (this assumes sulfur oxides mostl

consist of SO2

Another example is solvent degreasers. If the quantities of solvent added to and removed from a degreaser can b

measured accurately, the air emissions must equal the difference between the two. However, caution must be used

to account for the extra volume of effluent associated with the sludge that is removed.

Emission Factors

The most widely accepted method for estimating air emissions from common sources is through the use of emission factors published in reference documents. An emission factor is derived from facilities or processes simila

to yours. In most cases, these factors are simply averages of all available data of acceptable quality. These factor

are expressed in terms of pollutant generated per unit of process operation (for example, pounds of VOC per million-gallon fuel throughput). Emission factors may be the least reliable, but are the least costly method of estimatin

emissions.

EPA’s Office of Air Quality Planning and Standards (OAQPS) is responsible for air quality regulation, guidance documents, and other activities required by the CAA. The OAQPS established the Technical 

which is a collection of web pages on air pollution topics. TN maintains a web page called the Clearinghouse f

Inventories and Emission Factors (CHIEF) for downloading the latest information and tools for estimating emiss

of air pollutants and performing air emissions inventories. The CHIEF information desk can be reached at (9

541−1000, or at info.chief@epa.gov

Guidance Document AP-42

The most important source for emission factors is EPA’s guidance document, Compilation of Air Pollutant Emis

Factors, referred to as AP−42. These emission factors are based on empirical data collected through various resear

programs, and are generally written in terms of pounds of pollutants per unit quantity of process throughput.

For example, emission factors for emissions from boilers are published in the form of pounds of pollutants per 

million cubic feet of natural gas burned or pounds of pollutants per thousand gallons of fuel oil burned. The factors

are easy to use and are widely accepted by the state agencies as a method of estimating emissions.
Chapter 6 Air Emissions 6-

Each emission factor is given a quality rating ofA through E. Emission factors with a ratingof A are base

larger data populations and are the most reliable. Emission factors with a rating ofE should be considered o

questionable reliability.

AP−42 sections and other related estimation techniques can be downloaded from EPA’s website at www.epa.gov/c

Air Pollution Engineering Manual

Another excellent document for understanding the mechanisms of air pollution, techniques for estimating the rate

of emissions, and techniques for controlling air pollution is the Air Pollution Engineering Manual, edited by Wayne T.

Davis, 2000. This document is prepared by the Air and Waste Management Association and is commonly referred

as AP−4

TANKS Computer Program

TANKS is a user-friendly computer software program developedby EPA that computes VOC emissions from 

tanks. It is a widely accepted method of estimating the air emissions from

 Vertical and horizontal fixed-roof tanks

 Internal and external floating-roof tank

 Domed external floating-roof tanks

 Underground storage tanks

The mechanism of emissions from storage tanks is very complicated and is not easily estimated without computer

tools. The TANKS program relies on a database of chemical properties for over 100 organic compounds and mixt

(such as gasoline and diesel), as well as a meteorological database of over 250 cities in the U.S

The latest version of TANKS, Version 4.09D, requires an IBM-compatible PC with at least8 MB of RAM 

available hard disk space. The TANKS program and manual can be downloaded from EPA’s website at www.

ttn/chief/software/tanks/index.html.
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