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Attachment A

Supporting Documentation for 110(l) and 193 Demonstration 

Georgia Chapter 391-1-22, Georgia’s Clean Fueled Fleet Rules

Federal Regulations And The Ozone Nonattainment Area

The Clean Fuel Fleet Program (CFFP) is a requirement of section 182(c)(4) of the CAA for 

areas that have been designated serious nonattainment or above for the ozone National 

Ambient Air Quality Standards (NAAQS). CFFP is listed as an applicable requirement in 40 

CFR 51.900(f) (as well as in the proposed list of applicable requirements in 40 CFR 51.1100(o)). 

The Atlanta area was previously classified as severe for the previous 1-hour ozone NAAQS. 

The area was re-designated as attainment on June 15, 2005 [70FR 34660]. The Atlanta area 

was subsequently designated as nonattainment and classified as moderate for the 1997 8-hour 

ozone NAAQS. The Atlanta area was re-designated as attainment for the 1997 standard on 

December 2, 2013 [78FR 72040], prior to revocation of that standard. The Atlanta area is 

currently classified as a marginal nonattainment area for the 2008 8-hour ozone NAAQS

[73 FR 16483].

In addition, the currently proposed rule for the “Implementation of the 2008 National Ambient Air 

Quality Standards for Ozone: State Implementation Plan Requirements” [78FR 34178] 

proposes to replace the current anti-backsliding requirements by amending 40 CFR Part 51 

Subpart AA to address both the previously revoked 1-hour ozone NAAQS and the 1997 8-hour 

ozone NAAQS. The proposed anti-backsliding provisions for areas that are designated 

nonattainment for the 2008 NAAQS and attainment/maintenance for previous NAAQS are 

summarized in Table 2-2008 Ozone NAAQS Transition Obligations of the proposal as follows: 

“Area remains subject to existing section 175A maintenance plan for the previous NAAQS and 

requirements already in the SIP, subject to revision consistent with sections 110(l) and 193.” 

As indicated in the transmittal letter, 40 CFR 51.905(b) addresses state anti-backsliding 

requirements regarding implementation of applicable requirements after an area attains the 8-

hour ozone NAAQS as follows: “A State remains subject to the obligations under paragraphs 

(a)(1)(i) and (a)(2) of this section until the area attains the 8-hour NAAQS. After the area attains 

the 8-hour NAAQS, the State may request such obligations be shifted to contingency measures, 

consistent with sections 110(l) and 193 of the CAA...” 

Because the Atlanta area has attained the 1997 ozone NAAQS prior to revocation of that 

standard, Georgia’s Clean Fueled Fleet Rules may be shifted to contingency measures, 

consistent with sections 110(l) and 193 of the CAA. Section 193 is a general savings clause 

pertaining to regulations, standards, rules, notices, orders, and guidance promulgated or issued 

prior to November 15, 1990. CFFF was effective on May 22, 1994. Therefore, the substantive 

CAA provision EPD will demonstrate compliance with in this demonstration is that of section 

110(l).

Georgia Chapter 391-1-22, Clean Fuel Fleets Program

The Clean Fueled Fleets (CFF) Rules require that a percentage of a covered fleet’s covered 

vehicle purchases must meet the clean fueled fleet (low emission) vehicle standards. Covered 

fleets included any public or private fleet that operated 10 or more covered vehicles in a covered 
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area, which for Georgia only included 13 counties around metro-Atlanta. Covered vehicles 

included light duty vehicles up to heavy-duty vehicles with a gross vehicle weight rating (GVWR) 

of 26,000 lbs that were or were capable of being centrally fueled. Table 1 below lists each of the 

vehicle emission classifications. Acronyms in Table 1 are displayed at the bottom of the table. 

The program included a number of exemptions for various categories including vehicles 

garaged at a personal residence and not centrally fueled. Law enforcement and emergency 

vehicles were other popular exempt categories. The program for light duty vehicles was phased 

in from 1999 to 2001 with 30% of covered purchases having to meet the low emission vehicle 

(LEV) standards in 1999, 50% in 2000, and 70% in 2001. The percentage requirements remain 

at 70% for 2002 and after. Heavy-duty vehicle purchases had to meet a 50% requirement 

beginning with the 1999 model year, and the percentage remained the same for each 

subsequent model year. The CFFP started in 1999 with 612 covered fleets. This number 

dwindled down to 345 as of 2007. The overwhelming reason for this decline was the result of 

fleets understanding the “garaged at a personal residence and not centrally fueled” exemption 

and applying it. 

The U.S. Environmental Protection Agency (EPA) implemented the Tier II Light Duty Vehicle, 

Light Duty Truck, and medium-duty passenger vehicle standards for model year 2004 and later 

vehicles. These standards were fully phased in by model year 2009. The Tier II standards are

presented in 40 CFR Part 86 Subpart S, particularly in 86.1811-04, 86.1811-09, and 86.1811-10. 

The Tier II standards are more stringent than the low emission vehicle (LEV) standards in the

Clean Fueled Fleets Rules. These standards apply to all of the light-duty vehicle and light duty 

truck vehicle categories under the CFF Rule. EPA implemented new engine standards for 

heavy-duty diesel engines with a GVWR greater than 8500lbs beginning with the 2004 model 

year. These standards are more stringent than the LEV standards in the CFF Rules. The 

heavy-duty engine standards are presented in 40 CFR Part 86 Subpart S, particularly in 

86.1816-05, 86.1816-08, 86.005-10, 86.008-10, 86.004-11, and 86.007-11. Other sections 

within Subpart S cover the light duty Tier III standards, which provide even lower standards.

Equivalency Demonstration

In the Clean Fueled Fleets rule, covered fleets are required to purchase clean fueled vehicles 

(CFVs), which at a minimum must meet the low emission vehicle (LEV) standards. The U.S. 

Environmental Protection Agency (EPA) implemented the light duty vehicle Tier II and new 

heavy-duty diesel engine standards in 2004. Both of these standards reduce tailpipe emission 

standards significantly over the LEV standards. 

Georgia EPD analyzed the annual reports submitted for model years 2001 – 2004 and 2006 to 

determine the number of used vehicles purchased and the range of the model years. EPD 

determined that 98% of vehicle purchases are new. Only 2% of vehicles are purchased as 

used. Out of the used vehicles purchased, 80% would be 2004 and newer models. As a result, 

only 0.4% of vehicles purchased are 11 years or older. Since only, 30% of light duty and 50% of 

heavy-duty covered vehicle purchases are required to be clean fueled vehicles (CFVs), these 

used vehicles would not be required to be LEVs.

The Tier II standards were fully implemented in model year 2009. The table below illustrates the 

emission benefit of the Tier II and heavy-duty engine standards over LEV standards. The 

emission standards for Tier II in the table represent the 2009 model year and later (fully phased 

in). Although even more stringent heavy-duty engine standards were implemented by EPA in 

2007 and fully phased in by 2010, the table below presents the emission standards as 

implemented in 2004. 
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As illustrated in the table, the Tier II NOx standards have a benefit over the LEV standards 

ranging from 0.09 grams/mile to 0.99 grams/mile. The 2004 heavy-duty engine standards have 

a NMHC + NOx benefit of 1.4 grams/bhp-hr. These benefits are on a per vehicle basis. Since all 

of the Tier II and 2004 heavy-duty engine standards are equivalent or more stringent than the 

Clean Fuel Fleet standards, the emission reductions from these federal standards surpassed 

the emission reductions from Georgia Clean Fueled Fleets rules in 2004, when the federal 

standards were implemented.

EPA has also recognized that the Tier II vehicle and 2004 heavy-duty engine standards are 

equivalent or more stringent than the clean fueled vehicle (LEV) standards since 2004. A memo 

dated July 2, 2004 from EPA, Leila Cook, Group Manager in the Office of Air & Radiation, 

states:

“EPA has since published new emission standards that are more stringent than the 

CFFP standards for heavy-duty diesel and heavy-duty gasoline engines, as well as light 

duty vehicles. Therefore, vehicles certified to these new standards are considered 

acceptable for meeting the requirements contained in Part 88 for the Clean Fuel Fleets 

Program.

Fleet managers seeking to meet the requirements of the CFFP should be assured that 

all vehicles manufactured to meet the Tier 2 emission standards are equivalent to or 

cleaner than earlier emission levels mandated by the CFFP. Therefore, these new Tier 2 

vehicles are acceptable for use in meeting the CFFP requirements.”

LDV1, LDT

2 

<=6000 

GVWR, <= 

3750 LVW3

LDT <=6000 

GVWR, >3750 

LVW, <=5750 

LVW

LDT >6000 

GVWR,

<=3750 TW

LDT >6000 

GVWR, 

>3750 TW4 

<=5750 TW

LDT >6000 

GVWR,

>5750 TW

Light Heavy-Duty 

Truck >= 8500 

GVWR <=14,500 

GVWR

Medium HeavyDuty Truck >= 

8500 GVWR <= 

26,000 GVWR

Tier II 2010

NMHC+0.075 0.075 0.075 0.075 0.075 NMHC + NOx 2.4 2.4

NOx+0.11 0.11 0.11 0.11 0.11 PM 0.01 0.01

PM* 0.02 0.02 0.02 0.02 0.02

CFFV / LEV CFFV / LEV

NMHC+0.075 0.1 0.125 0.16 0.195 NMHC + NOx 3.8 3.8

NOx+0.2 0.4 0.4 0.7 1.1 PM 0.1 0.1

PM* 0.08 0.08 0.08 0.1 0.12

+

 Intermediate Life (50K miles)

* Full Usefile Life (120K miles)

NMHC 0 -0.025 -0.05 -0.085 -0.12 NMHC + NOx -1.4 -1.4

NOx -0.09 -0.29 -0.29 -0.59 -0.99

PM -0.06 -0.06 -0.06 -0.08 -0.1 PM -0.09 -0.09

4

 Test Weight

2

 Light Duty Truck

3

 Loaded Vehicle Weight

Light-Duty Vehicle and Truck Emission Levels in grams/mile Heavy-Duty Truck Emissions in grams/bhp-hr

Emission disbenefit per CFFV - grams / mile (negative sign illustrates benefit of Tier II over LEV) grams/bhp-hr

Table 1: Clean Fueled Fleet Emission Comparison

1

 Light Duty Vehicle
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Furthermore, EPA issued a letter to manufacturers on the Clean-Fuel Vehicle Standards on July 

21, 2005. This letter states:

“To determine equivalency, current certification emission standards for Tier 2 vehicles 

(LDVs, LDTs, and MDPVs), heavy-duty vehicles, heavy duty Otto cycle engines, and 

heavy-duty diesel engines were compared to CFV vehicle and engine emission

standards using the methodology outlined in the Attachment. The results of this analysis 

are summarized as follows:

Tier 2 LDVs, LDT1-4s, and MDPVs certified to the following Tier 2 bin standards are 

equivalent to or more stringent than CFV LEV emission standards:

LDV Bins 1-7 and Bin 9

LDTl Bins 1-7 and Bin 9

LDT2 Bins 1-9

LDT3 Bin 1-10

LDT4 Bin 1-10

MDPV Bin 1-114” 

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There are no CFV emission standards that correspond to the Tier 2 MDPV class but MDPVs meeting Tier 

2 Bins 1-1 1 are all equal to or more stringent than LDT4 CFV LEV standards.

The July 21, 2005 letter further states: 

“The following determinations are made for 2005 and later model year heavy-duty Otto

cycle engines and diesel engines: Current emission standards for heavy-duty engine 

Otto cycle engines and diesel engines are more stringent than CFV LEV heavy-duty Otto 

cycle engines, or heavy-duty diesel engine emission standards.”

Note: The previously listed Table 1 uses the Tier II emission standards phased in for model year 

2009 and later. As a result, Bins 8, 9, and 10 have been phased out.

EPA sent a memo dated April 17, 2006 to Air Program Managers on the Clean Fuel Fleet 

Program Requirements. The purpose of this memo was to provide information sent to 

manufacturers on determining equivalency between vehicle and engine standards in CFR Part 

86 (Tier II & new HD engines) and Part 88 (clean fueled vehicles). Below is a quote from the

memo:

“To meet the requirements of the Clean Fuel Fleet Program fleet managers can be 

assured that vehicles and engines certified to current Part 86 emission standards, which 

EPA has determined to be as or more stringent than corresponding CFV emission 

standards per the attached EPA Dear Manufacturer Letter meet CFV emission standards 

and CFFP requirements as defined in CFR Part 88. Such vehicles do not require a 

separate CFF certification or CFF label to qualify to participate in the CFF program. 

Thus, such vehicles are CFF compliant and are available to satisfy CFF SIP obligations.”

In summary, the Tier II vehicle standards and the 2004 heavy-duty diesel engine standards are 

clearly equivalent or more stringent than the low emission (clean fuel) vehicle standards. The 

emission standards taken from 40 CFR Part 86 in Table 1 illustrate that the Tier II and 2004 

heavy-duty engine standards provide significant emission benefits over the low emission vehicle 

standard. These three EPA memos have been included in this submittal as Appendix B, and

further clarify that EPA agrees that the Tier II and 2004 heavy-duty engine standards are more 
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stringent. As a result the existing EPA light duty and heavy duty emission standards can easily 

replace the requirements and benefits of the Clean Fueled Fleets Rule.

Conclusion

The Georgia Environmental Protection Division (EPD) is submitting for approval and 

incorporation, this proposed revision to Georgia’s State Implementation Plan (SIP), a request to 

remove its Clean Fueled Fleet Rules, Chapter 391-1-22, of the Georgia Rules to its contingency 

measures, in a manner consistent with the requirements of 110(l) and EPA’s proposed antibacksliding provisions.

Section 110(l) of the CAA, governs EPA’s ability to approve all SIP revisions. Specifically, 

section 110(l) states: 

Each revision to an implementation plan submitted by a State under this chapter shall be 

adopted by such State after reasonable notice and public hearing. The Administrator shall 

not approve a revision of a plan if the revision would interfere with any applicable 

requirement concerning attainment and reasonable further progress (as defined in section 

171 of this title), or any other applicable requirement of this chapter.

As shown in the equivalency demonstration, given that the Tier II vehicle standards and the 

2004 heavy-duty diesel engine standards are clearly more equivalent or more stringent than the 

low emission (clean fuel) vehicle standards, the removal of CFFP will not interfere with 

attainment or reasonable further progress, or any other applicable requirement of the act, EPD 

can assert that by moving this measure to contingency, this action is consistent with the 

requirements of 110(l) of the act as well as EPA’s proposed anti-backsliding provisions. 

Since the federal Tier II and 2004 heavy-duty diesel engine standards were more stringent than 

the CFFP standards as soon as the federal standards were implemented and since covered 

fleet owners were required to comply with both the CFFP and the federal standards, there was 

no, nor will there ever be, a shortfall in emissions reductions as a result of revocation of 

Georgia’s Clean Fueled Fleet Rules in 2014, Therefore, no substitute measure is required for 

the revocation of Georgia’s Clean Fueled Fleets rules.