United States Environmental Protection Agency, Pacific 

Southwest – Region 9

Clean Air Act Permit

Federal Indian Country Minor New Source Review Program

https://www.epa.gov/caa-permitting/tribal-nsr-permits-region-9

Technical Support Document (DRAFT)

General Air Quality Permit for New or Modified Minor Source Gasoline Dispensing

Facilities in Indian Country within California

September 2016
Table of Contents

Summary .................................................................................................................................................1

1. Applicability of the Federal Indian Country Minor NSR Program..........................................................2

2. Requirements for Developing and Issuing a General Permit ................................................................4

2.1 Purpose, Source Category, and Issuance Procedures .................................................................................4

2.2 Source Category Description - Gasoline Dispensing Facilities.....................................................................6

2.3 Procedures for Obtaining Coverage under a General Permit......................................................................7

3. Permit Content ..................................................................................................................................7

3.1 Required Permit Content.............................................................................................................................7

3.2 Emission Limitations....................................................................................................................................9

4. Eligibility Criteria for CA-GDF General Permit Coverage and Related Issues........................................20

4.1 Screening Procedures for Threatened or Endangered Species and Historic Properties.......................... 20

4.2 Exempt Equipment ................................................................................................................................... 20

4.3 Maximum Gasoline Throughput............................................................................................................... 20

4.4 Aboveground Storage Tanks....................................................................................................................... 21

4.5 Major Source of HAPs............................................................................................................................... 21

4.6 Air Quality Impact Analysis....................................................................................................................... 21

4.7 Good Engineering Stack Height................................................................................................................. 22

Appendix A: Emissions Calculations for Operating Limitation for GDFs in California .................................23
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Draft Technical Support Document

Clean Air Act Federal Indian Country Minor New Source Review Program

General Air Quality Permit for New or Modified Minor Source Gasoline 

Dispensing Facilities in Indian Country within California

Version 1.0

Last Modified: September 29, 2016

Summary 

This technical support document (TSD) provides the basis for the terms and conditions of the General Air Quality 

Permit for New or Modified Minor Source Gasoline Dispensing Facilities in Indian Country within California (CAGDF General Permit) under the Clean Air Act (CAA or Act) Federal Indian Country Minor New Source Review 

Program. The CA-GDF General Permit is being issued by the U.S. Environmental Protection Agency – Region 9 

(EPA Region 9) under the Federal Indian Country Minor New Source Review (Minor NSR) Program at 40 CFR 

49.151-49.161. The EPA is making this general permit available to permit certain existing or planned gasoline 

dispensing facilities (GDFs) in areas of Indian country within the geographic boundaries of California when such 

GDFs are subject to the requirements of the Minor NSR program. These areas of Indian country includes those

areas located in an Indian reservation or in another area of Indian country (as defined in 18 U.S.C. 1151) over 

which an Indian tribe, or the EPA, has demonstrated that the tribe has jurisdiction, and where there is no EPAapproved program in place. 

The CA-GDF General Permit that is the subject of this TSD is intended to provide a streamlined preconstruction 

permitting process under the Minor NSR program for certain GDFs located in Indian country within California, as 

well as to provide general consistency with the minor new source review (NSR) requirements generally 

applicable to GDFs in areas for which the State of California air permitting authorities have jurisdiction. The EPA 

previously issued a national permit by rule for the Minor NSR Program for GDFs (GDF Permit by Rule) to provide 

a similar option for streamlining the Minor NSR permitting process for GDFs in Indian country. However, the GDF 

Permit by Rule excluded GDFs in areas located within the geographic boundaries of the State of California. See 

40 CFR 49.164 and 80 FR 25068 (May 1, 2015).1

Owners and operators of GDFs that meet the eligibility requirements for the CA-GDF General Permit can use this 

general permit as a streamlined permitting option to the meet the preconstruction requirements of the Minor 

NSR Program. Owners and operators of such GDFs could also choose to apply to EPA Region 9 for a traditional 

source-specific permit to meet the preconstruction requirements of the Minor NSR program. 

In addition to this TSD, we have made available a set of permit-related documents in support of the CA-GDF 

General Permit. The CA-GDF General Permit documents are largely based on similar documents that the EPA 

made available associated with the EPA’s GDF Permit by Rule. These permit-related documents consist of the 

following: 

 1 See http://www.ecfr.gov/cgi-bin/textidx?SID=9428c598f5856da1b03fcbd009e07c60&mc=true&node=se40.1.49_1164&rgn=div8 and 

https://www.gpo.gov/fdsys/pkg/FR-2015-05-01/pdf/2015-09739.pdf.
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• General Permit: This document contains the requirements with which the source must comply, if 

approval of a request for coverage is granted. The emission limitations and monitoring, recordkeeping 

and reporting requirements are in the general permit.

• Request for Coverage: This document states the criteria for qualification for coverage under the general 

permit; gathers information on the source, the physical location, and the source contact; and requests 

technical information on facility equipment, throughput, and the attainment status of the area where 

the GDF will be located.

• Questionnaire: This document assists owners and operators in determining whether the source may be 

eligible for coverage under the general permit.

• Instructions: This document guides the applicant in filling out the Request for Coverage under the 

general permit.

• Potential to Emit (PTE) Calculator Spreadsheet: This document allows applicants to calculate the PTE of 

their GDF, based on inputs of the number of refueling positions at the GDF and the ozone attainment 

status of the GDF’s physical location, assuming compliance with the EPA’s standards and continuous 

operation throughout the year. The PTE Calculator spreadsheet generates potential emissions based on 

these inputs.

1. Applicability of the Federal Indian Country Minor NSR Program 

 

The CAA Federal Indian Country Minor NSR Program at 40 CFR 49.151–49.161 is potentially applicable to owners 

and operators of sources located, or planning to locate, in Indian reservations or in other areas of Indian country 

over which an Indian tribe, or the EPA, has demonstrated that the tribe has jurisdiction and where there is no 

EPA-approved program in place.

2 The Minor NSR Program requires owners and operators of certain new and 

modified existing sources of air pollution in such areas to obtain a Minor NSR permit prior to constructing or 

modifying their source. 3 This preconstruction permitting program is triggered for new or modified sources based 

on potential increases in air pollutants according to the applicability criteria in 40 CFR 49.153. Generally, source 

owners and operators in such areas first determine whether their new or modified source is subject to the CAA 

major NSR permitting program (pursuant to 40 CFR 52.21 for areas designated as attainment/unclassifiable for 

the National Ambient Air Quality Standards (NAAQS)) and/or 40 CFR 49.166 through 49.175 for areas designated 

as nonattainment for the NAAQS). For projects that are not subject to major NSR review, the owner and 

operator must evaluate whether the Minor NSR Program applies. 

We developed a general permit to streamline this permitting process for GDFs.

4 The CA-GDF General Permit is 

only intended for those sources that trigger the Minor NSR Program that are not major sources. 

 2 See 40 CFR 49.151(c)(1), 49.152(d)(4). See also 81 FR 35944, 35980 (June 3, 2016).

3 Also, submitting a permit application or request for coverage satisfies the requirement for true minor sources to register 

under the Minor NSR Program at 40 CFR 49.160(c)(1)(iii).

4 We chose to develop a general permit rather than a permit by rule for Indian country within California in order to allow for 

closer review of individual GDF sources in the area covered by the permit, given the unique air quality conditions in 

California and the associated permitting requirements. 
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In addition, we have determined it is appropriate to allow only minor sources (whether true minor or synthetic 

minor) to seek coverage under this general permit. That is, existing NSR major sources of any regulated NSR 

pollutant that propose modifications that are subject to the requirements of the Minor NSR program are not 

eligible to obtain coverage under this general permit, and must obtain a source-specific Minor NSR permit from 

the EPA prior to construction. 5 Further, individual sources that cannot comply with the terms and conditions in 

the general permit will also need to seek a source-specific permit. Our intent is to limit the use of this general 

permit to the most common and straightforward permitting actions. Modifications to major sources may require 

more extensive analyses than those typically associated with preconstruction review of minor sources. And, we 

expect the vast majority of GDFs in Indian country within California to be minor sources. 

When requesting coverage under the CA-GDF General Permit, owners and operators will be required to 

compare their source’s PTE to the NSR major source thresholds to determine if the source may qualify for 

coverage under the CA-GDF General Permit as a minor source. The applicability of the preconstruction review 

requirements of the Minor NSR Program is determined individually for each regulated NSR pollutant that would 

be emitted by the new or modified source. For this source category – GDFs – the NSR major source threshold for 

attainment areas is 250 tons per year (tpy) for any regulated NSR pollutant.6 The NSR major source thresholds 

for criteria pollutants in nonattainment areas are summarized in Table 1 below.

Table 1: NSR Major Source Thresholds for Nonattainment Areas 

Pollutant Nonattainment Classification NSR Major Source Threshold 

Ozone Marginal 100 tpy of VOC or NOX

Moderate 100 tpy of VOC or NOX

Serious 50 tpy of VOC or NOX

Severe 25 tpy of VOC or NOX

Extreme 10 tpy of VOC or NOX

PM10 Moderate 100 tpy

Serious 70 tpy

PM2.5 (or PM2.5

precursor7)

Moderate 100 tpy

Serious 70 tpy

CO Moderate 100 tpy

Serious 50 tpy

SO2 , NO2, lead No nonattainment classification 100 tpy

If a particular GDF is not a major source for a regulated NSR pollutant, then the owner and operator will 

evaluate whether the new or modified source has the potential to cause an emissions increase, based on PTE, 

equal to or greater than the minor NSR thresholds specified in the Minor NSR rule at 40 CFR 49.153. These minor 

NSR thresholds are listed in Table 2 below. Owners and operators applying for coverage under the CA-GDF

General Permit may calculate their GDF’s PTE using the PTE calculator provided with the CA-GDF General Permit 

 5 In addition, existing minor sources that become major sources as a result of the current modification are also not eligible 

for the CA-GDF General Permit. 6 There are 28 source categories that are subject to a lower major source threshold – 100 tons per year – in attainment 

areas. See 40 CFR 52.21(b)(1)(i)(a). GDFs are not one of the listed source categories. 7 See Appendix S to 40 CFR part 51, paragraph II.A.31.
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package. 8 Owners and operators of sources with potential emission increases above the minor NSR thresholds, 

and not subject to major NSR, must apply for and obtain a minor NSR permit prior to constructing or modifying 

their source. 

Table 2: Minor NSR Thresholdsa in 40 CFR 49.153 

Pollutant Attainment Area Nonattainment Area 

Carbon Monoxide (CO) 10 tons per year (tpy) 5 tpy

Particulate Matter 

(PM) 10 tpy Not Applicable

PM10 5 tpy 1 tpy

PM2.5 3 tpy 0.6 tpy

Sulfur Dioxide (SO2 ) 10 tpy 5 tpy

Nitrogen Oxides 

(NOX )

b 10 tpy 5 tpy

VOC b 5 tpy 2 tpy

Lead 0.1 tpy 0.1 tpy

Fluorides 1 tpy NA

Sulfuric Acid Mist 2 tpy NA

H2 S 2 tpy NA

Total Reduced sulfur 2 tpy NA

Reduced sulfur 

compounds 2 tpy NA a

If part of a Tribe’s area of Indian country is designated as attainment and another part as 

nonattainment, the applicable threshold for a proposed source or modification is determined based 

on the designation where the source would be located. If the source straddles the two areas, the 

more stringent thresholds apply.

b

In extreme ozone nonattainment areas, section 182(e)(2) of the Act requires any change at a major 

source that results in any increase in emissions to be subject to major NSR permitting. In other 

words, any changes to existing major sources in extreme ozone nonattainment areas are subject to a 

“0” tpy threshold, but that threshold does not apply to minor sources. 

2. Requirements for Developing and Issuing a General Permit 

 

We develop general permits under the Minor NSR Program consistent with the requirements in 40 CFR 49.156 –

General Permits. Below we discuss these general permit program requirements and how they form the basis for 

the CA-GDF General Permit. 

2.1 Purpose, Source Category, and Issuance Procedures 

The purpose of a general permit under the Minor NSR program is to simplify the permit issuance process for 

similar facilities so that a reviewing authority’s limited resources need not be expended for case-by-case permit 

development for such facilities. It also allows a reviewing authority to notify the public through one notice that 

 8 If a particular source has emission units not typically found at a GDF, whether or not not included in the GDF portion of 

the source, then the owner/operator must include the PTE of the other emissions units to determine whether the source is 

subject to the major or minor NSR programs.
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the EPA intends to apply these requirements to any eligible source that seeks coverage under the permit in the 

future, and decreases the time required for an individual minor source to obtain a preconstruction permit 

because the application process is shortened. A general permit may be issued for a category of emissions units 

or sources that are similar in nature, have substantially similar emissions and would be subject to the same or 

substantially similar requirements governing operations, emissions, monitoring, reporting and recordkeeping. 

“Similar in nature” refers to size, processes and operating conditions. The reviewing authority for the program 

will determine which categories of individual emissions units, groups of similar emissions units or sources are 

appropriate for general permits in its area. General permits are issued at the discretion of the reviewing

authority. 

In this case, the source category is a specific source type: GDFs. The GDF source type is a good candidate for a 

general permit given the common equipment at each facility, relative simplicity of the processes employed at 

such a facility, and the frequency with which GDFs are constructed/modified. A detailed description of the 

gasoline dispensing facility source category is provided below in Section 2.2.

General permits under the Minor NSR Program must be developed using much the same process that is used for 

traditional source-specific Minor NSR permits issued for individual sources. General permits also generally must 

include the same types of requirements as source-specific Minor NSR permits. 

All permits issued under the Minor NSR program must have emission limits developed according to 40 CFR 

49.154(c) – How will the reviewing authority determine the emission limitations that will be required in my 

permit? – and consider air impacts according to 40 CFR 49.154(d) – When may the reviewing authority require 

an air quality impacts analysis (AQIA)? In addition, 40 CFR 49.155 identifies specific requirements that must be 

included in each permit under the Minor NSR Program. These requirements, as specified in 40 CFR 49.155(a)(1) 

through (7), include: general requirements, emission limitations, monitoring requirements, recordkeeping 

requirements, reporting requirements, a severability clause, and other additional provisions. 40 CFR 49.155(b) 

also specifies how a permit can become invalid under the Minor NSR Program. 40 CFR 49.156(b) provides that 

general permits must be issued in accordance with these requirements.

40 CFR 49.156(d) specifies that a general permit must contain the permit elements listed in 40 CFR 49.155(a), as 

well as the requirements from 40 CFR 49.156(d), including the following:

• Identification of the specific category of emissions units or sources to which the general permit applies, 

including any criteria that the emissions units or sources must meet to be eligible for coverage under the 

general permit.

• The name and mailing address of the reviewing authority to whom the application must be submitted.

• The procedure to obtain any standard application forms that the reviewing authority may have 

developed.

• Other application requirements deemed necessary by the reviewing authority.

How we considered and included these requirements is discussed in greater detail in Section 3 – Permit Content.

In addition, the public participation procedures for issuance of a general permit under the Minor NSR program 

are largely the same as those for source-specific permits per 40 CFR 49.157. Final permit issuance and 

administrative and judicial review procedures for general permits are specified in 40 CFR 49.159, and are 

generally the same as those governing source-specific permits issued under the Minor NSR program. The
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reviewing authority’s final permit decision for a general permit becomes effective 30 days after the service of 

notice of the final permit decision, unless: 

1. A later date is specified in the permit, or

2. Review of the final permit decision by the EPA’s Environmental Appeals Board is requested under 40 CFR 

49.159(d), or

3. The reviewing authority makes the permit effective immediately upon issuance if no comments 

requested a change in the draft permit or a denial of the permit.

Under the Minor NSR Program, issuance of a final general permit following the exhaustion of agency 

administrative review procedures is considered final agency action with respect to all aspects of the general 

permit except its applicability to an individual source. 40 CFR 49.159(d)(8). The sole issue that may be appealed 

after an individual source is approved to construct under a general permit is the applicability of the general 

permit to that particular source. The letter notifying an individual source of approval or denial under a general 

permit is considered a final agency action for purposes of judicial review and is not subject to administrative 

review by the EPA’s Environmental Appeals Board. See 40 CFR 49.156(b)(3), 49.156(e)(6).

2.2 Source Category Description - Gasoline Dispensing Facilities 

The term “gasoline dispensing facility (GDF)” means any stationary source which dispenses gasoline into the fuel 

tank of a motor vehicle, motor vehicle engine, nonroad vehicle, or nonroad engine, including a nonroad vehicle 

or nonroad engine used solely for competition. These facilities include, but are not limited to, facilities that 

dispense gasoline into on- and off-road, street, or highway motor vehicles, lawn equipment, boats, test engines, 

landscaping equipment, generators, pumps, and other gasoline-fueled engines and equipment.9

 A GDF can also 

include equipment that dispenses diesel fuel. In addition, a GDF could be an operation supporting other 

activities at a facility that otherwise requires a permit.10

Gasoline is delivered by tank trucks to GDFs and then transferred to highway motor vehicles and nonroad 

equipment and engines. GDFs include all retail outlets such as traditional gasoline service stations, convenience 

stores, truck stops, and hypermarkets (e.g., warehouse clubs and big box stores), marinas, as well as private and

commercial outlets, such as centrally-fueled fleets, government operations, and private businesses such as 

farms and landscaping operations. The CA-GDF General Permit is not available to sources that store and transfer 

aviation gasoline at airports or other similar sources that dispense fuel through mobile (portable) fueling 

equipment. 

The operations and equipment at a typical GDF are described in AP 42, Chapter 5.2, Transportation and 

Marketing of Petroleum Liquids. 11 Emissions of volatile organic compounds (VOC) at GDFs occur due to 

evaporation, displacement of vapors during unloading of the fuel into onsite storage tanks, displacement of 

vapors during refueling of vehicles, and breathing losses from the storage tanks. As discussed in greater detail in 

Section 3.2.1.1, emissions from GDF are generally addressed by two categories of vapor recovery control 

technologies, referred to as Stage I and Stage II. 

 9 See 40 CFR 63.11132. 10 This general permit only covers emission units at the GDF, and other emissions units may require a separate permit. The 

other emission units could be covered by a source-specific permit, a general permit, or a permit by rule. 11 AP 42, Chapter 5.2, Transportation and Marketing of Petroleum Liquids, June 2008, 

http://www.epa.gov/ttn/chief/ap42/ch05/index.html.
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2.3 Procedures for Obtaining Coverage under a General Permit 

40 CFR 49.156(e) specifies the procedures for obtaining coverage under a general permit. We have included 

these requirements in the Request for Coverage document developed for the CA-GDF General Permit. As such, 

by completing the Request for Coverage, owners/operators will meet or be notified of the requirements 

applicable to them in order to qualify for coverage under the CA-GDF General Permit. The requirements include: 

• The timeframe when a source can begin to request coverage under the CA-GDF General Permit once it is 

finalized; 

• The requirement to submit a copy of the Request for Coverage to the tribe in the area where the source 

is locating; 

• The timeframe for action by the reviewing authority after a Request for Coverage is submitted, including 

a completeness determination, and notification of approval or denial; 

• Clarification that the approval or denial of the Request for Coverage is a final action for purposes of 

judicial review only for the issue of whether the source qualifies for coverage under the CA-GDF General 

Permit;

• The requirement to prominently post a copy of the letter granting the Request for Coverage at the site 

where the source is locating;

• The timeframe for commencing construction if the Request for Coverage is approved;

• The requirement to comply with the all conditions and terms of the CA-GDF General Permit if approval is 

granted; and 

• The option for requesting a source-specific permit instead of coverage under the CA-GDF General 

Permit. 

3. Permit Content 

As discussed in Section 2 above, the terms and conditions of the CA-GDF General Permit are based on the 

required permit content and analyses specified in the Minor NSR rule. The required permit content for Minor 

NSR permits is listed in 40 CFR 49.155 – What information must my permit include? Below we describe the basis 

for the CA-GDF General Permit conditions.

3.1 Required Permit Content 

40 CFR 49.155(a)(1) – General Requirements

40 CFR 49.155(a)(1) specifies the following elements that each Minor NSR permit must include: the effective 

date of the permit and the date by which the owner/operator must commence construction in order for the 

permit to remain valid; the emissions units subject to the permit and their associated emission limitations; and 

monitoring, recordkeeping, and reporting requirements to assure compliance with the emission limitations. 

The CA-GDF General Permit includes all of these required elements, except for the specific emissions units 

subject to the permit. Because of the nature of general permits, we believe it is more appropriate to identify the 

specific emission units covered by the General Permit for a particular source in the Approval of Request for 

Coverage, as the CA-GDF General Permit makes enforceable the Approval of the Request for Coverage. 

However, all of the emission limits applicable to the equipment at a GDF are included in the CA-GDF General 

Permit.
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40 CFR 49.155(a)(2) – Emission Limitations

40 CFR 49.155(a)(2) states that each Minor NSR permit must include the emission limitations determined by the 

reviewing authority under 40 CFR 49.154(c) for each affected emissions unit. The permit must also include 

annual allowable emissions limits for sources needing enforceable emission limitations to lower their potential 

to emit. 40 CFR 49.154(c) – How will the reviewing authority determine the emission limitations that will be 

required in my permit? – describes the case-by-case control technology review that must be used by the 

reviewing authority to determine the appropriate level of control. In carrying out the case-by-case control 

technology review, the reviewing authority must consider the following factors:

1. Local air quality conditions;

2. Typical control technology or other emission reduction measures used by similar sources in surrounding 

areas;

3. Anticipated economic growth in the area; and

4. Cost-effective emission reduction alternatives.

In addition, 40 CFR 49.154(c) provides that the reviewing authority must require a numerical limit on the 

quantity, rate, or concentration of emissions for each regulated NSR pollutant emitted by each affected 

emissions unit for which such a limit is technically and economically feasible. 40 CFR 49.154(c) further provides 

that the emission limitations required by the reviewing authority may consist of numerical limits on the 

quantity, rate or concentration of emissions; pollution prevention techniques; design standards; equipment 

standards; work practices; operational standards; requirements relating to the operation or maintenance of the 

source; or any combination thereof. The emissions limitations must assure that each affected emission unit will 

comply with all requirements of 40 CFR parts 60, 61, and 63, as well as any federal or tribal implementation 

plans that apply to the unit. Finally, the emissions limitations required may not rely on a stack height that 

exceeds good engineering practice or any other dispersion technique, except as allowed by 40 CFR 51.118(b).

Our detailed analysis supporting the emissions limitations in the CA-GDF General Permit is provided below in 

Section 3.2.

40 CFR 49.155(a)(3) – Monitoring Requirements

40 CFR 49.155(a)(3) provides that each Minor NSR permit must include monitoring that is sufficient to assure 

compliance with the emissions limitations that apply to the affected emissions units at the source. In this case, 

the CA-GDF General Permit requires monitoring of the required vapor control recovery systems on a weekly 

basis to determine whether the equipment is in good working order. For sources located in extreme ozone 

nonattainment areas, this monitoring shall be performed daily. The CA-GDF General Permit also requires: (1) 

initial and ongoing performance testing to ensure that the vapor recovery systems are designed and working 

properly, and (2) for GDFs in ozone nonattainment areas, regular monitoring of the vapor recovery systems 

through an in-station diagnostics (ISDs) system. 

40 CFR 49.155(a)(4) – Recordkeeping Requirements 

40 CFR 49.155(a)(4) provides that each Minor NSR permit must include recordkeeping requirements sufficient to 

assure compliance with the emissions limitations and monitoring requirements, including the elements listed in 

40 CFR 49.155(a)(4)(i) and (ii). In addition to the recordkeeping elements in 40 CFR 49.155(a)(4)(i) and (ii), the 

CA-CDF General Permit also requires records of the weekly (or daily) inspections of the vapor recovery systems, 

the reports from the ISD system, and the results of each performance test required by the permit. Furthermore, 
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the permittee must maintain records of monthly gasoline throughput and the 12-month rolling total of gasoline 

throughput.

40 CFR 49.155(a)(5) – Reporting Requirements

40 CFR 49.155(a)(5) requires that each Minor NSR permit include the reporting requirements listed in 40 CFR 

49.155(a)(5)(i) and (ii) related to annual reports and reporting of deviations. The CA-GDF General Permit 

includes such requirements, as well as requiring notifications of construction/modification, notification of 

change in owner or operator, notification of closure, and requirements for performance test reports.

40 CFR 49.155(a)(6) – Severability Clause

40 CFR 49.155(a)(6) provides that each Minor NSR permit include a severability clause to ensure the continued 

validity of the other portions of the permit in the event of a challenge to a portion of the permit. The CA-GDF 

Permit includes the required severability clause.

40 CFR 49.155(a)(7) – Additional Provisions

40 CFR 49.155(a)(7) requires that each Minor NSR permit contain provisions stating the requirements in 

paragraphs (a)(7)(i) through (vii) of that section. The CA-GDF General Permit contains the required provisions. 

These conditions are found in the General Provisions section of the permit.

Section 3.2 Emission Limitations 

In this section, we discuss the basis for the emissions limitations in the CA-GDF General Permit, based on the 

requirements in 40 CFR 49.155(a), including the control technology review required by 40 CFR 49.154(c). We did 

not conduct an air quality impact analysis in developing these limitations. Instead, in determining whether to 

grant coverage under the CA-GDF General Permit for individual sources, we will consider whether such an 

analysis is needed for that particular source. See the discussion below in Section 4.6. 

Section 3.2.1 Control Technology Review 

As discussed above, 40 CFR 49.154(c) describes the case-by-case control technology review that must be 

conducted by the reviewing authority to determine the appropriate level of control for the permitted source. In 

carrying out the control technology review, the reviewing authority must consider the following four factors:

1. Local air quality conditions;

2. Typical control technology or other emission reduction measures used by similar sources in surrounding 

areas;

3. Anticipated economic growth in the area; and

4. Cost-effective emission reduction alternatives.

Below, we discuss our analysis of these factors in the context of the CA-GDF General Permit.

Section 3.2.1.1 Available Control Technologies at GDFs 

The primary pollutants at GDFs are VOC emissions caused by the volatile nature of gasoline. There are two major 

categories of control technologies for GDFs, which are referred to as Stage I and Stage II. Both technologies are 
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designed to reduce VOC emissions by recovering gasoline vapors (referred to as “vapor recovery”) that are 

emitted as part of the processes at GDFs.

Stage I vapor recovery is intended to reduce emissions during unloading of the gasoline fuel from a tanker truck

to storage tanks at the GDF. Stage I vapor recovery minimizes such emissions by using submerged filling or 

bottom filling, in which the fill pipe opening is below the liquid surface level in the receiving tank. Liquid 

turbulence is controlled significantly during submerged/bottom filling, resulting in low vapor generation. 

Emissions during unloading can also be controlled with vapor balance. The vapors displaced from the receiving 

tank during unloading are routed back into the transport tank and returned to the loading terminal. Stage I 

vapor balance requires that the GDF source control emissions from the storage tanks during unloading of the 

gasoline fuel from the tanker truck. This typically involves having an extra tube hooked up to the receiving tank 

to transfer VOC-laden vapors displaced from the tank back into the tanker truck for processing/disposal back at 

the loading terminal. As discussed below, the requirements in 40 CFR part 63, subpart CCCCCC, include a 

comprehensive set of Stage I vapor control requirements.

Stage II vapor recovery is intended to reduce evaporative emissions from vehicle refueling and diurnal breathing

(everyday evaporative losses from storage tanks) at GDFs, and control such emissions using vapor recovery 

devices. 12 Recovery of vapors displaced from the vehicle fuel tank during refueling can be accomplished with 

pump-based controls and/or vehicle-based onboard refueling vapor recovery (ORVR) systems. Pump-based 

Stage II vapor recovery requires that the GDF equip its dispensing pumps with nozzles that recover the VOCladen fumes that are displaced from the vehicle fuel tank during fueling. A coaxial tube and special nozzle are 

designed to attach to the vehicle’s fuel port and to recover vented fumes during filling. The recovered fumes are 

pumped back into the fuel storage tank. Storage tank diurnal breathing loss emissions are controlled by properly 

maintaining pressure in vent pipes and vacuum valves. ORVR controls are installed by the vehicle manufacturer. 

ORVR controls started phasing-in in 1998 and have been required for all new vehicles since model year 2006.

13

Our control technology review for CA-GDF General Permit is limited to these two types of vapor recovery, Stages 

I and II, as we are not aware of any other available control technologies for GDFs. As such, our determination of 

which emission limits to include in the CA-GDF General Permit is based on whether it is appropriate to require 

either, or both, of these types of vapor recovery.

Section 3.2.1.2 Factor 1 – Local Air Quality Conditions 

Local air quality conditions – Local air quality considerations were a key consideration in setting the emission 

limitations in the CA-GDF General Permit. This permit was developed separately from the EPA’s national GDF 

Permit by Rule, which is applicable outside of the State of California, to ensure that the permit conditions would 

be appropriate for the air quality conditions within the State of California, which are in many locations in Indian 

country much worse than those in other areas of Indian country across the nation. To appropriately address the 

air quality conditions within California, the CA-GDF General Permit applies controls that are generally consistent 

 12 AP 42, Chapter 5.2, Transportation and Marketing of Petroleum Liquids, June 2008, 

http://www.epa.gov/ttn/chief/ap42/ch05/index.html. 13 See Section I.B, pp. 3 of Stage II Vapor Recovery Systems Issues Paper, U.S. EPA, Office of Air Quality Planning and 

Standards, Emissions Monitoring and Analysis Division, Emissions Factors and Policy Applications Group (D243-02), August 

12, 2004. ORVR requirements are for motor vehicles and are outside the scope of what can be required for stationary 

sources.
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with those required for similar sources in surrounding areas; i.e., Stage I vapor recovery in all areas and Stage II 

vapor recovery in ozone nonattainment areas. Our decision to apply Stage I and II controls is discussed in more 

detail below in Section 3.2.1.3, where we discuss our consideration of control technologies used by similar 

sources in surrounding areas. In some instances, our control technology determination adopts the same level of 

control as the national GDF Permit by Rule, and in others it is more stringent than the national GDF Permit by 

Rule. 

The CA-GDF General Permit may be used only by smaller GDFs, in terms of emissions, i.e., those with 

approximate emissions of less than 30 tons per year of VOC in attainment areas 14, and marginal and moderate 

ozone nonattainment areas, and those with emissions of less than 10 tons per year in serious, severe, and 

extreme ozone nonattainment areas. We are implementing this restriction by including permit conditions 

limiting the amount of gasoline that can be dispensed annually (based on a 12-month rolling total), which is 

referred to as a throughput limit. Section 3.2.2 contains a discussion of these limits. In addition, as discussed in 

Section 4.6, the permitting authority has the discretion to determine that an individual source should not be 

approved to use the CA-GDF General Permit and must instead seek a source-specific Minor NSR permit due to 

local air quality conditions. 

Section 3.2.1.3 Factor 2 – Typical Control Technologies 

Typical control technology or other emission reduction measures used by similar sources in 

surrounding areas – For this factor, we considered two main sets of requirements: (1) the minimum 

technology and emission limitations that must be met by GDFs nationally under the federal requirements of 40 

CFR parts 60, 61, and 63; and (2) the technology and emission limitations required by the State of California. At 

a minimum, the emission limitations in the CA-GDF General Permit must ensure compliance with parts 60, 61, 

and 63 (see 40 CFR 49.154(c)(4)). As explained above, our review of these requirements focused on the two 

types of control technologies for GDFs – Stage I and II vapor recovery, and the specific requirements (emission 

limits, work practices standards, etc.) that are applied to GDFs when applying Stage I or II vapor recovery 

controls. Our review of emission reduction measures used by similar sources in the surrounding areas 

considered the following potential equipment at GDFs: 15

• Gasoline storage tanks and filling operations;

• Gasoline pumping operations;

• Diesel storage tanks and filling operations;

• Diesel pumping operations; and

• Stationary emergency engines.

Review of Potentially Applicable Federal Requirements:

The potentially applicable federal requirements that we considered for the CA-GDF General Permit are:

 14 For the purposes of this TSD, “attainment areas” include those areas that are designated attainment, unclassifiable, or 

attainment/unclassifiable.

15 The CA-GDF General Permit covers only covers the type of equipment typically found at a GDF. Other equipment at the 

source may require a separate Minor NSR permit. Such other equipment potentially could be permitted under a sourcespecific permit, a general permit, or a permit by rule.
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• 40 CFR part 60, subpart IIII – Standards of Performance for Stationary Compression Ignition Internal 

Combustion Engines;

• 40 CFR part 60, subpart JJJJ – Standards of Performance for Stationary Spark Ignition Internal 

Combustion Engines;

• 40 CFR part 60, subpart Kb – Standards of Performance for Volatile Organic Liquid Storage Vessels 

(Including Petroleum Liquid Storage Vessels) Which Construction, Reconstruction, or Modification 

Commenced after July 23, 1984;

• 40 CFR part 63, subpart CCCCCC – National Emission Standards for Gasoline Dispensing Facilities; and

• 40 CFR part 63, subpart ZZZZ – National Emission Standards for Hazardous Air Pollutants for Stationary 

Reciprocating Internal Combustion Engines.

During the development of the national GDF Permit by Rule, the EPA conducted a review of the requirements 

for GDFs of other state and local agencies, in addition to the federal requirements in parts 60 and 63 listed 

above. 16 That review resulted in the EPA’s adoption of the control technology requirements for Stage I vapor 

recovery standards in 40 CFR part 63, subpart CCCCCC, in addition to certification or work practice standards for 

emergency engines. 17 In this case, with respect to attainment areas, for the CA-GDF General Permit we are 

finding that this prior analysis, as it pertains to those areas already attaining the NAAQS, continues to be 

appropriate, and we are utilizing the same requirements for such areas as those applicable under the national 

GDF Permit by Rule, with one exception. As discussed below, we are not including the control requirements for 

emergency engines in the CA-GDF General Permit.

We included permit conditions in the CA-GDF General Permit that incorporate Stage I requirements from 40 CFR 

part 63, subpart CCCCCC: 18

• 40 CFR 63.11116(a) – requirement to minimize vapor releases;

• 40 CFR 63.11117(b) – requirement to use submerged filling;

• 40 CFR 63.11117(c) – exception of certain tanks from 63.11117(b);

• 40 CFR 63.11118(b)(1) - requirement to use Stage I dual-point vapor balance systems;

• 40 CFR 63.11118(c) – exception of certain tanks from 63.11118(b)(1);

• 40 CFR 63.11118(d) – requirements for cargo tanks;

• 40 CFR 63.11120(a) – initial and ongoing testing requirements;

• Table 1 to Subpart CCCCCC of 40 CFR 63 – management practices; and

• Table 2 to Subpart CCCCCC of 40 CFR 63 – management practices for cargo tanks.

These requirements are also included in the national GDF Permit by Rule. In addition, we included a permit 

condition requiring sources to meet the exemption criteria for emergency engines discussed above.

 16 See Section 5.2.2 of the Background Document: Air Quality Permit by Rule for New or Modified True Minor Source 

Gasoline Dispensing Facilities in Indian Country.

17 See Section 4.3 of the Background Document: Air Quality Permit by Rule for New or Modified True Minor Source Gasoline 

Dispensing Facilities in Indian Country.

18 We expect that all GDFs seeking coverage under the CA-GDF General Permit will be required to have Stage I vapor 

controls under the federal NESHAP regulations at 40 CFR 63.11118, which require GDFs that dispense more than 1,200,000 

gallons per year to use Stage I vapor controls.
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We did not include requirements for diesel storage tanks or diesel pumping operations in the CA-GDF General 

Permit conditions. There are currently no control requirements in 40 CFR parts 60, 61, or 63 for such equipment. 

This is the same approach that was taken for the national GDF Permit by Rule. Diesel is less volatile than gasoline 

and has significantly less VOC emissions as compared to gasoline operations. Given these limited emissions, we 

are not proposing any specific standards for diesel storage tanks or diesel pumping operations in the CA-GDF 

General Permit. However, emissions from diesel storage tanks and diesel pumping operations must still be 

reflected in a GDF’s emissions calculations, and must be included in any Request for Coverage under the CA-GDF 

General Permit. 19

Specifically, we did not include requirements from these regulations:

40 CFR part 60, subparts IIII and JJJJ and 40 CFR part 63, subpart ZZZZ –The EPA has revised the Minor 

NSR program to exempt certain emergency generator engines from the requirement to obtain a 

permit.20 We expect most GDFs to either not have emergency engines or to have engines that fall within 

this exemption. We are not including the requirements from these regulations and are limiting the CAGDF General Permit to only those new or modified GDFs that would have exempt emergency engines, or 

in the case of severe and extreme ozone nonattainment areas, no new or modified emergency engines. 

See 40 CFR 49.153(c)(9) and additional discussion in Section 4.2. We note that these regulations are selfimplementing and therefore all emergency engines at GDFs will need to meet the applicable 

requirements of these regulations. Existing engines will need to comply with subpart ZZZZ and new 

engines will need to either comply with subpart IIII for diesel engines or subpart JJJJ for spark ignition 

engines, regardless of whether these requirements are included in the CA-GDF General Permit.

• 40 CFR part 60, subpart Kb – While this regulation is potentially applicable to the storage tanks at GDFs, 

the regulation specifically exempts storage vessels located at GDFs. See 40 CFR 60.110b(b)(6). In 

addition, diesel storage tanks are also exempt because the maximum true vapor pressure of diesel 

(approximately 0.4 kilopascals) is less than 3.5 kilopascals.

Review of California Requirements:

Our review focused on the air quality control requirements typically applied to GDFs in areas of California within 

the State’s jurisdiction. Due to significant air quality problems in California, the California Air Resources Board

(CARB) has developed an extensive set of regulations for controlling VOC emissions from GDFs. These 

regulations include requirements for both Stage I and Stage II vapor recovery.21 In addition to the requirements 

 19 The PTE Calculator includes estimates for emissions from diesel storage tanks and pumping operations. 20 In May 2014, the EPA revised the Minor NSR Program to exempt certain emergency generator engines from the 

requirement to obtain a permit. Under 40 CFR 49.153(c)(9), emergency generator engines at a single source are “exempt” if 

the combined maximum horsepower (hp) rating of all emergency generator engines is below 1,000 hp in attainment areas 

or 500 hp in ozone nonattainment areas classified as Serious or lower. If the source consists of only exempt equipment, 

then the owner or operator is not required to obtain a minor NSR permit. 21 As discussed above, the EPA refers to the two categories of vapor recovery control technologies at GDFs as Stage I (to 

address emissions from transfer of gasoline to storage tanks) and Stage II (to address emissions from gasoline dispensing

and diurnal breathing). In California, these types of vapor recovery are referred to as Phase I and Phase II, respectively. EPA 

Region 9 has taken the approach here of using the Stage I and II terminology for consistency with other EPA documents and 

regulations that use the terms.
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established by the CARB, we also examined permits for GDFs from California air districts in ozone nonattainment 

areas, including the South Coast Air Quality Management District, as discussed below. 

Specific California permits, rules, executive orders, and guidance reviewed:

• Certification Procedures CP-201 and CP-206;

• Types of Vapor Recovery Systems certified by CARB22;

• South Coast Air Quality Management District (South Coast AQMD) Rule 461 − Gasoline Transfer and 

Dispensing; and

• Sample South Coast AQMD Evaluation for Permits to Construct/Operate

Nearly all GDFs in the U.S. are required to have Stage I vapor recovery controls as the use of such controls is 

required by 40 CFR part 63, subpart CCCCCC. Until a 2012 EPA rulemaking, Stage II vapor recovery controls for 

gasoline pumps during vehicle refueling were required under the CAA for serious, severe, and extreme ozone 

nonattainment areas. The 2012 rulemaking concluded that these Stage II controls were no longer required for 

these nonattainment areas due to the widespread use of onboard refueling vapor recovering (ORVR) technology 

in the U.S. motor vehicle fleet, which also serves to limit emissions during vehicle refueling. 23 (77 FR 28772, May 

16, 2012)

For Minor NSR Program national general permits and permits by rule, the EPA has generally taken the approach 

of requiring more stringent emission controls in areas with poorer air quality in order to ensure that sources in 

these areas are minimizing emissions and that air quality is protected. We received comments on the proposed 

national GDF Permit by Rule recommending that the EPA require Stage II controls in states that still require 

Stage II controls, and that we require California’s Stage II controls in all serious, severe or extreme 

nonattainment areas.

24 In light of the 2012 rulemaking, however, the EPA did not include Stage II requirements 

in ozone nonattainment areas as part of the national Permit by Rule. Nevertheless, Stage II controls continue to 

be required for GDFs in California ozone nonattainment areas by the CARB to address the ongoing air quality 

problems in California.

25

Given California’s continued use of Stage II, in issuing the final GDF Permit by Rule, EPA determined that it would 

not make the GDF Permit by Rule available for use in Indian country within the geographical boundaries of the 

State of California. Instead, we decided to develop a general permit or permit by rule specifically for GDFs in 

Indian country within California in order to consider the appropriateness of requiring additional controls, such as

Stage II vapor recovery, in California nonattainment areas to support a level playing field and to address the air 

quality problems in California. 

Since April 2009, California has required all applicable GDFs to comply with its Stage II enhanced vapor recovery 

(EVR) system standards to control evaporative emissions from vehicle refueling and from breathing losses from 

 22 https://www.arb.ca.gov/vapor/eo-evrphaseII.htm 23 After the effective date of this 2012 action, a states previously required by the CAA to implement a Stage II program 

could take appropriate action to remove the program from its State Implementation Plan (SIP). 24 80 FR 25068, 25077 (May 1, 2015). 25 As a result, there are about 7,500 gas stations using Stage II controls in California. 

http://www.arb.ca.gov/vapor/workshops/op2015/nov.%202015%20over%20pressure%20workshop%20-

%20final%20nov%205.pdf
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underground storage tanks (USTs). These standards require greater emission reductions than were typically seen 

for Stage II controls in other ozone nonattainment areas outside of California – 95% control in California versus 

60-90% in other areas.

26 Additionally, California Stage II EVR standards require GDFs with Stage II equipment to 

install, properly operate, and maintain CARB-certified Stage II EVR equipment that is compatible with vehicle 

manufacturers’ ORVR equipment. California also requires GDFs with throughputs of more than 600,000 gallons 

per year of gasoline to install In-Station Diagnostic (ISD) Systems. An ISD System is an alarm system that provides 

continuous real-time monitoring of critical emission-related vapor recovery system parameters and 

components, and that alerts the station operator when a failure mode is detected so that corrective action can 

be taken within 2 hours. If timely corrective action is not taken, the ISD System will shut down the gasoline 

dispensing systems. 

We have determined that these requirements – i.e., the use of Stage II EVR system with ISD systems – are 

appropriate to include in the CA-GDF General Permit for EPA-designated ozone nonattainment areas to protect 

air quality based on the unique air quality problems facing California, and to ensure general consistency with 

the emission reduction measures used by similar sources in surrounding areas.

27 While CARB only requires ISD 

systems for GDFs that dispense greater than 600,000 gallons of gasoline per year, we are requiring ISD systems 

in the CA-GDF General Permit for all GDFs in EPA-designated ozone nonattainment areas. This is appropriate 

because under the Minor NSR Program, GDFs dispensing less than 600,000 gallons of gasoline per year would 

not be expected to trigger the requirements for a Minor NSR permit. 

We are including these requirements in the CA-GDF General Permit for ozone nonattainment areas by adopting 

the standards issued by the CARB for Stage II EVR systems with ISD systems, rather than the requirements of a 

particular local California air district. California air districts may have their own set of GDF requirements to 

implement the CARB’s standards. However, given that there are 35 air districts in California, we have 

determined that adopting uniform requirements for GDFs in all the EPA-designated ozone nonattainment areas 

covered by the CA-GDF General Permit based on the CARB’s standards is the most appropriate and 

straightforward approach. The standards we are adopting are the CARB’s Certification Procedures in CP-201 for 

ERV systems. In order to meet the CP-201 standards, owner and operators must use CARB-certified 

equipment. 28 These standards are mainly a combination of control efficiency requirements and work practice 

standards, but also directly limit system VOC emissions to 0.38 lb/1,000 gallons of gasoline. Current CP-201 

standards for Stage II ERV systems include, but are not limited to:

 26 Stage II Vapor Recovery Systems Issues Paper, U.S. EPA, Office of Air Quality Planning and Standards, Emissions 

Monitoring and Analysis Division, Emissions Factors and Policy Applications Group (D243-02), August 12, 2004. 27 We note that the CARB applies the requirement for GDFs to install Stage II controls in areas that are nonattainment for 

the State Ambient Air Quality Standards for ozone. In addition, California has an Air Toxics Control Measure that requires 

Stage II controls for all new GDFs in order to reduce benzene emissions. The consideration of benzene, a hazardous air 

pollutant, is outside the scope of EPA’s Minor NSR Program.

28 We note that California’s air quality programs are not approved by EPA to apply under the Clean Air Act within any Indian 

reservation or any other area of Indian country over which an Indian tribe, or the EPA, has demonstrated that a tribe has 

jurisdiction. Thus, the specific air quality requirements and associated equipment certification requirements adopted by 

California are not approved by EPA to apply for purposes of the State’s Clean Air Act NSR program within such areas. It is 

only by virtue of EPA’s adoption of these requirements as appropriate permit conditions for the federal CA GDF General 

Permit, as we are doing in this case in implementing the federal NSR program, that the requirements are made applicable in 

such areas of Indian country.
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• All systems shall meet a hydrocarbon efficiency rate of 95% or greater and/or an emission rate for 

gasoline not to exceed 0.38 pounds per 1,000 gallons. This includes refueling and vent emissions, and 

pressure-related fugitives. 

• Spillage, including drips from spouts, shall not exceed 0.24 pounds per 1,000 gallons of gasoline. 

• System must be compatible with ORVR. 

• System is operated with a liquid retention nozzle “spitting” rate not to exceed 100 milliliters (ml) per 

1,000 gallons of gasoline and 

• e not to exceed 1.0 ml per nozzle per test.

• System is operated with low permeation hoses with a permeation rate not to exceed 10.0 grams per 

meter squared per day (g/m2

/day).

• Underground Storage Tank (UST) pressure criteria, based on a 30-day rolling average, shall not exceed 

+0.25 inches of water (in. H2O, daily average pressure and shall not exceed +1.50 in. H2O, daily high 

pressure). 

• Each nozzle shall meet the following criteria:

o Capable of refueling any vehicle that complies with the fillpipe specifications and can be fueled 

by a conventional nozzle;

o “Dripless,” meaning that no more than three drops shall occur following each refueling 

operation; and

o Shall comply with the following:

 The terminal end shall have a straight section of at least 2.5 inches (6.34 centimeters) in 

length;

 The outside diameter of the terminal end shall not exceed 0.840 inch (2.134 

centimeters) for the length of the straight section; and

 The retaining spring or collar shall terminate at least 3.0 inches (7.6 centimeters) from 

the terminal end.

• For the nozzle/dispenser compatibility: the vapor check valve shall be closed when hung and the holdopen latch disengaged when hung.

• The unihose MPD configuration shall be such that only one hose/nozzle is allowed per dispenser side.

• The Stage II vapor riser shall be a minimum of an inch nominal ID.

• The vapor return piping shall meet the following requirements:

o No liquid or fixed blockage;

o Minimum of 3-inch nominal ID after first manifold;

o Have a recommended slop of 1⁄4 inch per foot; and

o Have a minimum slope of 1/8 inch per foot.

• The vapor return pipe shall have a maximum allowable length of pipe established during the certification 

process.

• The liquid condensate traps shall have an automatic evacuation system.

• The connectors and fittings shall have no indication of vapor leaks with liquid leak detection solution 

(LDS) or bagging.

The current version of CP-201 is dated April 23, 2015. The CA-GDF General Permit requires that owners and 

operators subject to the CA-GDF General Permit, Version 1.0, comply with the standards in this version of CP201 dated April 23, 2015. Owners and operators will meet this requirement by installing EVR and ISD systems

that are certified by CARB as meeting the CP-201 standards. There are currently three such systems certified by 

CARB executive orders and included in the CA-GDF General Permit: VR-202-U, executed on August 31, 2016; VR204-S, executed on March 28, 2016; and VR-208-A, executed on September 23, 2009.
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We anticipate that revisions to these standards and executive orders will be made by the State of California in 

the future under state law. Such revisions would not affect owners and operators that have been issued an 

Approval of the Request for Coverage under the CA-CDF General Permit in terms of changing applicable CA-CDF 

General Permit requirements. 29 We anticipate that we may periodically update the CA-GDF General Permit to 

reflect evolving air quality control requirements for GDFs. Such revisions would only affect owners and 

operators that seek general permit coverage for construction or modification of a GDF following those revisions 

to the CA-GDF General Permit. That is, any new requirements resulting from revisions to the CA-GDF General 

Permit would not apply retroactively. 30

In addition, while CARB has a set of Stage I vapor recovery standards, we are not adopting those standards in 

their entirety into the CA-GDF General Permit. CARB’s Stage I vapor recovery standards are very similar, but not 

identical to, the EPA’s Stage I standards in 40 CFR part 63, subpart CCCCCC, which we are applying to all sources 

in the CA-GDF General Permit. One major difference between these standards is that CARB’s standards require 

GDFs to achieve at least a 95% control efficiency, whereas the EPA’s Stage I standards do not require all sources 

to meet a specific control efficiency. We have determined it is appropriate for GDF’s in ozone nonattainment 

areas to be required to meet the CARB control efficiency standard and have, therefore, included it in the CA-GDF 

General Permit for ozone nonattainment areas.

Review of California Requirements for Aboveground Storage Tanks

California also has statewide Stage I and Stage II requirements for aboveground storage tanks (ASTs) in ozone 

nonattainment areas.31 The Stage I requirements that we have included in the CA-GDF General Permit apply 

equally to ASTs and USTs. However, at this time, we have chosen not to cover under the CA-GDF General Permit

those new or modified GDFs located in ozone nonattainment areas that require a minor NSR permit and that 

utilize new or modified ASTs. While Stage II controls for USTs have been in place since 2009 in California, similar 

requirements for ASTs only became effective in California in 2015 and generally are not widely used at GDFs.

32

Currently, we expect that most owners and operators of GDFs needing Minor NSR permits will use USTs. New or 

modified GDFs in ozone nonattainment areas located in California that include ASTs as part of the new or 

modified source will need to seek a source-specific preconstruction Minor NSR permit from the EPA if their new 

or modified source requires a Minor NSR permit. If ASTs become more commonplace for GDFs subject to the 

Minor NSR program, we may revise the CA-GDF General Permit in the future to allow GDFs utilizing ASTs in 

nonattainment areas the option of seeking Minor NSR permit coverage under the CA-GDF General Permit. 

Section 3.2.1.4 Factor 3 – Anticipated Economic Growth 

The reviewing authority is to consider anticipated economic growth as part of the control technology review. We 

find that it is unlikely that emission increases from GDFs, as permitted under the CA-GDF General Permit, will 

pose unique or unprecedented impacts on air quality in any particular area within the geographic scope of the 

General Permit regardless of the anticipated economic growth for any such area. We continue to find that the 

 29 An owner or operator may follow a revised version of CP-201, but only after obtaining EPA-approval that it is at least as 

stringent as the April 23, 2015 version. 30 When the EPA updates general permits for a particular source category, we intend to distinguish the permits from each 

other by referring to the particular “version” of the general permit. We intend to identify the particular version that an 

owner/operator must comply with in the Approval of the Request for Coverage. 

31 California has separate sets of requirements for ASTs and USTs. 32 https://www.arb.ca.gov/vapor/astcompdeadlines052316.pdf
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selected control technologies are protective of air quality, consistent with the controls used in the surrounding 

areas, and, as discussed below, economically feasible, and therefore appropriate for purposes of the CA-GDF 

General Permit. 

Section 3.2.1.5 Factor 4 – Cost-Effective Alternatives

As noted above, the CA-GDF General Permit contains emission reduction requirements that are generally 

consistent with what is required for GDFs across California in areas within the state’s jurisdiction. As such, the 

chosen technologies are considered widely available and economically feasible and further consideration of 

additional, potentially cost-effective alternatives is not necessary at this time. We intend to periodically review 

technology costs in the future to determine when other potentially cost-effective technologies become widely 

available.

Section 3.2.1.6 Summary of Control Technology Review 

In conducting our control technology review, we have determined that it is appropriate, based on the four 

factors above and for the reasons discussed above, to require GDFs covered by the CA-GDF General Permit to 

apply these control technologies:

1. For all GDFs, the EPA’s existing Stage I vapor recovery requirements in 40 CFR part 63, subpart CCCCCC.

2. For GDFs in ozone nonattainment areas, Stage I controls will need to meet a specific 95% control 

efficiency.

3. For GDFs in ozone nonattainment areas, the CARB’s Stage II requirements for EVR, with ISD systems. 

3.2.2 Operating Limitations

In addition to Stage I and II vapor recovery controls, in developing the CA-GDF General Permit, we considered 

whether it would be appropriate to require operating limits on gasoline throughput to limit the size of sources 

eligible for the CA-GDF General Permit to the most common types of GDFs needing a Minor NSR permit. The CAGDF General Permit is intended as a streamlined permitting option for typical GDFs that do not require 

extensive review and analysis during the permitting process. In order to determine if an upper gasoline 

throughput limit was necessary, we examined the throughputs of gasoline that would correspond to emissions 

of VOC at NSR major source levels. 

GDFs tend to be located near dense populations and where vehicle traffic is greater. For example, the average 

GDF in Los Angeles County, California dispenses about 1.8 million gallons per year, while the average GDF in 

Mendocino County, California dispenses about 700,000 gallons per year. 33

The traffic congestion and wait times at the pumps at a gasoline station serve as limiting factors on the potential 

emissions of VOC due to vehicle tank refueling. A throughput of 1.8 million gallons of gasoline per year, for 

example, results in approximately 1.8 tons per year of VOC emissions in ozone attainment areas using Stage I 

controls, and 1.4 tons in ozone nonattainment areas when using the minimum federal requirement of Stage I 

 33 Based on station counts and throughput data in the California Energy Commission’s California Annual Retail Outlet Report 

Results (CEC-A15) – 2014, dated May 18, 2016. Available here: 

http://www.energy.ca.gov/almanac/transportation_data/gasoline/piira_retail_survey.html
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controls.

34 These actual throughputs are well below the applicable NSR major source thresholds for VOC, which 

are as low as 10 tons per year for extreme ozone nonattainment areas.

Based on this information, most GDFs would not be major sources under the NSR program in even extreme 

ozone nonattainment areas, although a GDF could be co-located with other equipment that would need to be 

included in determining whether the source is a major source. As discussed above, this CA-GDF General Permit is 

only available for use by minor NSR sources and not available for use by major NSR sources. Considering the fact

that most GDFs will have emissions well below the major NSR thresholds, we believe that it is appropriate to set 

operating limits to protect air quality by limiting the general permit to only the most routine permitting actions. 

As such, we set the throughput limits, using the GDF PTE Calculator, to ensure (1) that GDFs covered by the CAGDF General Permit are not major sources under the NSR program, and (2) ensures GDFs have a limited air 

quality impact using limits that are within typical throughputs of GDFs.

The operating limits in the CA-GDF General Permit reflect the emission rates listed in Table 4. To ensure the 

entire GDF is not a major source, these operating limits are source-wide limits, applying to the entire GDF and 

not just the new or modified equipment. For GDFs located in serious, severe or extreme ozone nonattainment 

areas, the CA-GDF General Permit limits throughput of gasoline to less than 15,000,000 gallons per year based 

on a 12-month rolling total (See Appendix A for the calculation of this throughput limit). This ensures that even 

the largest retailers should be able to qualify for the CA GDF General Permit in serious, severe, and extreme 

ozone nonattainment areas. For GDFs located in attainment and marginal or moderate ozone nonattainment 

areas, the General Permit limits throughput of gasoline to less than 25,000,000 gallons per year based on a 12-

month rolling total. (See Appendix A for the calculation of this throughput limit). These limits are clearly well 

within the expected maximum operating rates of most GDFs, and are the same operational limits as those in the 

EPA’s national GDF Permit by Rule.

Table 3: Throughput Operating Limitations for Gasoline Dispensing Facilities 

Throughput Limit 

Serious, Severe or Extreme 

Ozone Nonattainment 

Areas 

Ozone Attainment, Areas and 

Moderate or Marginal Ozone 

Nonattainment Areas 

Gasoline usage 15,000,000 gallons/year 25,000,000 gallons/year

Table 4: Corresponding Emission Rates for the Operation Limits in the General Permit 

Pollutant of 

Concern 

Serious, Severe or 

Extreme Ozone 

Nonattainment Areas 

Moderate or Marginal Ozone 

Nonattainment Areas Ozone Attainment Areas 

VOC 6.98 tpy 11.63 tpy 24.75 tpy

 

 

 

 

 34 This analysis represents actual emissions and not potential emissions, which are expected to be higher. The potential 

emissions vary in attainment and nonattainment areas based on expected differences in the VOC content of gasoline in the 

two types of areas. 
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4. Eligibility Criteria for CA-GDF General Permit Coverage and Related Issues 

4.1 Screening Procedures for Threatened or Endangered Species and Historic Properties 

Prior to obtaining coverage under the CA-CDF General Permit, owners and operators must satisfactorily 

complete the screening processes for their source that are specified for threatened or endangered species and 

historic properties. EPA will provide confirmation that that the procedures were satisfactorily met. Appendices 

A and B to the Request for Coverage contain detailed directions to assist source owners and operators in

completing these processes.

4.2 Exempt Equipment 

The Minor NSR Program exempts some small equipment from the requirement to obtain a Minor NSR 

permit.35 GDFs with exempt equipment are eligible for the CA-GDF General Permit even though the CA-GDF 

General Permit does not include requirements for exempt equipment. To create a General Permit that is 

protective of air quality, we have limited eligibility for coverage under the CA-GDF General Permit to only 

those GDF sources with exempt emergency engines for all areas other than severe and extreme ozone 

nonattainment areas. In severe and extreme ozone nonattainment areas, GDFs with new or modified engines 

are not eligible for coverage under the California GDF General Permit. 

The exemption from the requirement to obtain a permit for such equipment does not allow a source owner 

or operator to exclude the emissions from the exempt equipment when calculating a source’s overall 

potential to emit. As such, applicants seeking coverage under the CA-GDF General Permit must include 

emissions from all equipment that will be constructed or modified in determining whether their source is a 

minor source. We expect some GDFs to include emergency generators, a type of equipment that is potentially 

exempt from permitting under the Minor NSR program. 

Specifically, the NSR program exempts emergency generators designed solely for the purpose of providing 

electrical power during power outages when the total maximum manufacture’s site-rated horsepower of all 

units is below 500 in nonattainment areas and 1,000 in attainment areas. We expect most GDFs to either not 

have emergency engines or to have exempt emergency engines. Therefore, generally, to be eligible for the 

CA-GDF General Permit, the GDF source must be seeking to construct or modify emergency engines that meet

the regulatory exemption thresholds for such engines as specified in the Minor NSR Program, or, in the case 

of severe or extreme ozone nonattainment areas, the proposed project must not include emergency engines. 

See 40 CFR 49.153(c).

4.3 Maximum Gasoline Throughput 

 

The gasoline dispensing throughput limits discussed in Section 3.2.2 will be used to determine whether a source 

is eligible for the CA-GDF General Permit. Only sources that will dispense less than the throughput limits will 

potentially be eligible for the general permit. See Table 4. These throughput limits are reflected in the CA-GDF 

General Permit and each covered GDF must be able to meet the limits on an on-going basis. 

 35 This exemption does not apply to new major sources or major modifications at existing major sources.
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4.3.1 Triggering the Minor NSR Program 

Owners and operators of proposed new or modified GDFs that are potentially subject to the requirements of the 

Minor NSR program in the areas of Indian country within California are encouraged to consult with their 

reviewing authority to determine whether their proposed project would actually trigger the requirements of the 

Minor NSR Program. Only those new or modified GDFs with potential emissions above the minor NSR threshold 

must obtain preconstruction permits. As ORVR continues to become prevalent in the vehicle fleet, potential 

emissions from GDFs will continue to decrease. We expect that due to ORVR in the vehicle fleet, by 2027, 

potential emissions of GDFs without Stage II EVR systems will be equal to emissions from GDFs with Stage II EVR 

systems. We expect to re-evaluate the requirements for GDFs periodically, and to revise them as needed. 

4.4 Aboveground Storage Tanks 

As discussed above in Section 3.2.1.3, proposed new or modified GDFs that include aboveground storage tanks 

(ASTs) and that are located in ozone nonattainment areas are not eligible for coverage under the CA-GDF 

General Permit. We expect the overwhelming majority of GDFs to use USTs rather than ASTs. However, new or 

modified GDFs that include ASTs and that are located in attainment areas are eligible for the CA-GDF General 

Permit.

4.5 Major Source of HAPs 

 

The CA-GDF General Permit is limited to GDFs that are not a major source of hazardous air pollutants (HAPs). 

This is to ensure that a source covered by the CA-GDF General Permit would not potentially be subject to 

additional requirements not included in the CA-GDF General Permit, as well as to ensure that GDFs seeking 

coverage under the CA-GDF General Permit can avoid the additional permitting requirements of the title V 

operating permit program. 

A source is a major source of HAP if its potential to emit is equal to or greater than 10 tpy for a single HAP 

and/or 25 tpy for any combinations of HAPs. As part of the EPA’s national GDF Permit by Rule,

36 the EPA 

calculated the potential HAP emissions from GDFs and determined that a GDF would not be a major source of 

HAP until VOC emissions are approximately 200 tpy. Because we estimate that GDFs covered by the CA-GDF 

General Permit will have VOC emissions of 30 tpy or less, we can reasonably conclude that GDFs covered by the 

CA-GDF General Permit will not be major sources of HAPs. 

Should a source include other HAP emitting equipment not covered by the CA-GDF General Permit, then those 

emissions would also have to be included in determining whether a GDF would be a major source of HAPs. Such 

sources would not be eligible for the CA-GDF General Permit if source-wide potential emissions of HAPs exceed 

the major source thresholds. 

 

4.6 Air Quality Impact Analysis 

The Minor NSR regulations provide that if the reviewing authority has reason to be concerned that the 

construction of a proposed minor source or modification would cause or contribute to a NAAQS or PSD 

 36 See Section 5.2.1 on page 12 of the Background Document: Air Quality Permit by Rule for New or Modified True Minor 

Source Gasoline Dispensing Facilities in Indian Country.
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increment violation, it may require the owner and operator of the proposed source or modification to conduct 

and submit an air quality impact analysis (AQIA) 40 CFR 49.154(d). We have determined that the control 

technology and other requirements of this permit generally should be protective of air quality, and we did not 

conduct an AQIA as part of the development of the CA-GDF General Permit. Instead, in determining whether to 

grant coverage under the CA-GDF General Permit for individual sources, we will consider, according to the 

criteria in 40 CFR 49.154(d), whether an AQIA is needed for that particular source prior to granting an Approval 

of the Request for Coverage. However, given the limited emissions expected from GDFs, particularly with CAGDF General Permit’s proposed controls, we do not expect that we would determine that there is such a 

concern, or that an AQIA would be needed, in most cases. 

4.7 Good Engineering Stack Height 

The emission limitations required in the CA-GDF General Permit must not be affected in a manner by so much of 

a stack’s height as exceeds good engineering practice (GEP) or by any other dispersion technique. We do not 

expect that any stack at a GDF would exceed GEP. In addition, none of the emission limitations were based on 

stack height or dispersion modeling. In the event the reviewing authority requires an AQIA, and a stack height 

exceeds GEP, then the reviewing authority would have to follow the procedures for notifying the public and 

providing for a public hearing.

 
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Appendix A: Emissions Calculation for Operating Limitation for GDFs in California 

1. Calculation for Serious, Severe, and Extreme Ozone Nonattainment Areas – 15,000,000 

gallons/year 

 

Key for Calculations:

Abbreviation Description VOC Emission Factor 

(lbs/1,000 gallons) 

 

STF Storage Tank Filling Losses 0.30

STB Storage Tank Breathing Losses 0.25

DIS-NA Dispensing Losses – Nonattainment Area 0.38

TP Gasoline Throughput (gallons/year) 15,000,000

CF Conversion Factor (1 ton/2,000 lbs) 1 / 2,000

EF Emission Factor -

Note: Calculations are done for the year 2016. The EF for dispensing losses is dependent upon year and location. Assume 

worst case scenario storage tank breathing losses of 0.25 lb/1,000 gallons. 

A. GDF Operations: 

VOC Emissions STF = TPSTF x EFSTF x CF 

= 15,000,000 (gallons/year) x 0.30/1,000 (lbs/gallon) x 1/2,000 (ton/lb) 

= 2.25 tpy VOC

VOC Emissions STB = TPSTB x EFSTB x CF 

= 15,000,000 (gallons/year) x 0.25/1,000 (lbs/gallon) x 1/2,000 (ton/lb) 

= 1.875 tpy VOC

VOC Emissions DIS-NA = TP DIS-A x EF DIS-NA x CF 

= 15,000,000 (gallons/year) x 0.38/1,000 (lbs/gallon) x 1/2,000 (ton/lb) 

= 2.850 tpy VOC

Total VOC Emissions from GDF Operations = 6.98 tpy 

B. Emergency Engine (Serious Areas Only, maximum of 500 horsepower (hp), combined):

Worst-case emission factor for VOC assumes a gasoline emergency engine. 

VOC Emissions = capacity (hp) x conversion factor (kW/hp) emission factor x conversion factor (lbs/g) x 500

 (hrs/year) x 1 ton/2,000 lb

=500 hp x 0.7457 kW/hp x 9.124 g VOC/kW-hr x 1 lb/453.5928 g x 500 hrs/year x 

 1 ton/2,000 lbs

= 1.875 tpy

C. Total PTE: 6.98 tpy in severe and extreme areas, and 8.86 tpy in serious areas
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2. Calculation for Moderate and Marginal Ozone Nonattainment Areas – 25,000,000 gallons/yr 

Key for Calculations:

Abbreviation Description VOC Emission Factor (lbs/1,000 

gallons) 

 

STF Storage Tank Filling Losses 0.30

STB Storage Tank Breathing Losses 0.25

DIS-NA Dispensing Losses –

Nonattainment Area 0.38

TP Gasoline Throughput 

(gallons/year) 25,000,000

CF Conversion Factor (1 ton/2,000 

lbs) 1 / 2,000

EF Emission Factor -

Note: Calculations are done for the year 2016. The EF for dispensing losses is dependent upon year and location. Assume 

worst case scenario storage tank breathing losses of 0.25 lb/1,000 gallons. 

A. VOC Emissions from GDF Operations:

VOC Emissions STF = TPSTF x EFSTF x CF 

= 25,000,000 (gallons/year) x 0.30/1,000 (lbs/gallon) x 1/2,000 (ton/lb) 

= 3.75 tpy VOC

VOC Emissions STB = TPSTB x EFSTB x CF 

= 25,000,000 (gallons/year) x 0.25/1,000 (lbs/gallon) x 1/2,000 (ton/lb) 

= 3.125 tpy VOC

VOC Emissions DIS-NA = TP DIS-A x EF DIS-NA x CF 

= 25,000,000 (gallons/year) x 0.38/1,000 (lbs/gallon) x 1/2,000 (ton/lb) 

= 4.750 tpy VOC

Total VOC Emissions from GDF Operations = 11.63 tpy 

B. Emergency Engine (500 horsepower (hp), combined):

Worst-case emission factor for VOC assumes a gasoline emergency engine. 

VOC Emissions = capacity (hp) x conversion factor (kW/hp) emission factor x conversion factor (lbs/g) x 500

 (hrs/year) x 1 ton/2,000 lb

= 500 hp x 0.7457 kW/hp x 9.124 g VOC/kW-hr x 1 lb/453.5928 g x 500 hrs/year x 

 1 ton/2,000 lbs

= 1.875 tpy

C. Total PTE: 13.51 tpy
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3. Calculation for Ozone Attainment Areas – 25,000,000 gallons/yr 

Key for Calculations: 

Abbreviation Description VOC Emission Factor 

(lbs/1,000 gallons) 

STF Storage Tank Filling Losses 0.30

STB Storage Tank Breathing Losses 0.25

DIS-NA Dispensing Losses –Attainment Area 1.43

TP Gasoline Throughput (gallons/year) 25,000,000

CF Conversion Factor (1 ton/2,000 lbs) 1 / 2,000

EF Emission Factor -

Note: Calculations are done for the year 2016. The EF for dispensing losses is dependent upon year and location. Assume 

worst case scenario storage tank breathing losses of 0.25 lb/1,000 gallons. 

A. VOC Emissions from GDF Operations:

VOC Emissions STF = TPSTF x EFSTF x CF 

= 25,000,000 (gallons/year) x 0.30/1,000 (lb/gallon) x 1/2,000 (ton/lb) 

= 3.6 tpy VOC

VOC Emissions STB = TPSTB x EFSTB x CF 

= 25,000,000 (gallons/year) x 0.25/1,000 (lb/gallon) x 1/2,000 (ton/lb) 

= 3.0 tpy VOC

VOC Emissions DIS-NA = TP DIS-A x EF DIS-NA x CF 

= 25,000,000 (gallons/year) x 1.43/1,000 (lb/gallon) x 1/2,000 (ton/lb) 

= 17.16 tpy VOC

Total VOC Emissions from GDF Operations = 24.75 tpy 

B. Emergency Engine (1,000 horsepower (hp), combined):

Worst-case emission factor for VOC assumes a gasoline emergency engine. 

VOC Emissions = capacity (hp) x conversion factor (kW/hp) emission factor x conversion factor (lbs/g) x 500

 (hrs/year) x 1 ton/2,000 lb

= 1,000 hp x 0.7457 kW/hp x 9.124 g VOC/kW-hr x 1 lb/453.5928 g x 500 hrs/year x 

 1 ton/2,000 lbs

= 3.75 tpy

C. Total PTE: 28.5 tpy