Air Resou^rces Board 

Mary D. Nichols, Chairman


1001 I Street • P.O. Box 2815


Sacramento, California 95812 • www.arb.ca.gov

,% .^

^ 

Matthew Rodriquez


Secretary for


Environmental Protection

^_ 

:.^.. .^.. 

Edmund G. Brown Jr.


Govemor 

June 26, 2013 

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^ ^ ^---^ Mr. Robert Perciasepe ^ 

Acting Administrator ;; ; ^ `" ^ 

U.S. Environmental Protection Agency ^ ^' ; ^_ 

EPA Docket Center, Air and Radiation Docket, Mail Code 2822T ^^^ _ 

1200 Pennsylvania Avenue NW ^ ;^- 

Washington, DC 20460 iD 

Attention Docket ID No. EPA-HQ-OAR-2011-0135

Re: The California Air Resources Board's Comments on the U.S. Environmental


Protection Agency's Control of Air Pollution from New Motor Vehicles: 

Tier 3 Motor Vehicle Emission and Fuel Standards (Federal Register Vol. 78, 

No. 98, pp. 29816-30191) 

Dear Acting Administrator Perciasepe: 

The California Air Resources Board (CARB) appreciates the opportunity to provide 

comments on the recently published Notice of Public Rulemaking for the U.S. 

Environmental Protection Agency (U.S. EPA) Motor Vehicle Emission and Fuel 

Standards Tier 3 program. CARB strongly supports the Tier 3 program as proposed 

and offers our comments to the program in the attachment to this letter. We believe the 

program as proposed represents a noteworthy strengthening of the current Tier 2 

program and will achieve significant criteria emission reductions from the national 

passenger vehicle fleet. 

Our comments on the Tier 3 proposal are divided into nine areas: 

• The proposed Tier 3 exhaust emission requirements; 

• The proposed Tier 3 evaporative emission and On-Board Refueling Vapor 

requirements; 

• The proposed Tier 3 particulate matter standards and test procedures; 

• The proposed Tier 3 On-Board Diagnostic requirements; 

• The proposed Tier 3 In-Use Verification program; 

• The Tier 3 fuel standards; 

• The Tier 3 certification test fuel specifications; 

• The economic benefits of Tier 3; and 

• The proposed test methods for unregulated and special pollutants. 

The energy challenge facing California is real. Every Califomian needs to take immediate action to reduce energy consumption.


For a list of simple ways you can reduce demand and cut your energy costs. see our website: http://www.arb.ca.gov . 

California Environmental Protection Agency 

Printed on Recycled Paper
^	3 

Mr. Robert Perciasepe 

June 26, 2013 

Page 2 

CARB shares U.S. EPA's goal of reducing vehicle emissions to improve air quality. 

Despite significant progress in reducing smog-forming and particulate matter emissions 

from the passenger vehicle fleet, California needs further reductions in order to meet 

state and federal ambient air quality standards. To help achieve these standards, 

CARB adopted the Low-Emission Vehicle (LEV III) regulations last year as part of our 

Advanced Clean Cars program. The Advanced Clean Cars program combines the 

control of smog-causing pollutants and greenhouse gas emissions into a single 

coordinated package of requirements for model years 2015 through 2025 and assures 

the development of environmentally superior cars that will continue to deliver the 

performance, utility, and safety vehicle owners have come to expect. 

CARB is mindful of the cooperative effort between CARB and U.S. EPA in the 

development of the new vehicle exhaust emission standards for California's LEV III 

program and the federal Tier 3 program. It is our intent to evaluate the Tier 3 rule once 

it is finalized to determine where it is appropriate to further align the LEV III regulation 

with the federal rule, without sacrificing the stringency and emission benefits of the 

LEV III program. Since any delay in finalizing Tier 3 would potentially impact the 

implementation date of this important program, CARB urges U.S. EPA to proceed 

expeditiously to finalize the program before the end of this year. We also look forward 

to continue working with U.S. EPA in an attempt to resolve any remaining differences 

between the two programs after the Tier 3 regulations are finalized. 

Our primary goal continues to be improving air quality in California. To this end, 

California has a separate and unique Zero-Emission Vehicle Program, which we will 

continue to pursue in order to ensure the prompt and successful deployment of 

advanced technology zero-emission vehicles. Accordingly, any determination of the 

extent to which it would be appropriate for California to incorporate elements of the 

Tier 3 program into our light-duty vehicle program would need to take into consideration 

our ability to sustain progress towards California's long term plans for transforming the 

vehicle fleet for reduction of criteria pollutants. In addition, any modifications to the LEV 

III program must be structured to assure that the emission reductions provided by the 

California program will be maintained. 

If you need additional technical information on our comments, please contact 

Ms. Annette Hebert, Chief of our Mobile Source Control Division, at (626) 575-6807. 

Sincer ly, 

. s y,'L	G ^j ^ 

Ma D. ichots	^^ 

Chai 

Attachment 

cc:	See next page.
#	^ ^

Mr. Robert Perciasepe 

June 26, 2013 

Page 3 

cc:	Mr. William Charmley 

Acting Director 

U.S. Environmental Protection Agency 

Assessment and Standards Division 

2000 Traverwood Drive 

Ann Arbor, MI 48105 

Mr. Richard W. Corey 

Executive Officer 

Dr. Alberto Ayala 

Deputy Executive Officer 

Mr. Aron Livingston 

Assistant Chief Counsel 

Office of Legal Affairs 

Dr. Michael Benjamin, Chief 

Monitoring and Laboratory Division 

Ms. Annette Hebert, Chief 

Mobile Source Control Division 

Ms. Cynthia Marvin, Chief 

Stationary Source Division
;^" ^	^.
Page 1

^^i_is^.il^^t1_1►^ 

California Air Resources Board's Comments on the Proposed Tier 3 


Rulemaking 

Comments on Proposed Tier 3 Exhaust Emission Requirements 

The California Air Resources Board (CARB) is fully supportive of the proposed Tier 3 

federal test procedure (FTP) and supplemental federal test procedure (SFTP) 

requirements. With a few exceptions, the proposed requirements mirror the LowEmission Vehicle (LEV III) requirements effectively addressing manufacturers' concerns 

regarding compliance with both national and California emission programs. In order to 

further harmonize program requirements of both agencies, CARB intends to align the 

LEV III rule with a number of the Tier 3 FTP and SFTP requirements after Tier 3 is 

finalized as noted below and offers the following comments on the proposal. 

Tier 3 Federal Test Procedure Requirements 

Comment 1— Small Volume Manufacturer Provisions 

California has traditionally provided relief to Small Volume Manufacturers (SVM) 

(primarily producers of high performance vehicles), recognizing that they are at a 

competitive disadvantage with larger manufacturers in terms of both investment and 

engineering resources. In addition, they must compete with full line manufacturers who 

are able to offset the emissions of their low volume high performance vehicles with 

higher volume, lower emission vehicles. For these reasons, LEV III provides slightly 

less stringent emission standards for SVMs. 

Unlike LEV III, Tier 3 requires SVMs to defer compliance with the Tier 3 fleet average 

standards until 2022. The Notice of Proposed Rulemaking (NPRM) requests comment 

on this and an alternative requirement that matches LEV III requirements through 2024 

and then requires that SVMs meet Tier 3 fleet average requirements in 2025. Since 

harmonization of SVM requirements will allow these manufacturers to certify the same 

vehicle to both programs, CARB recommends that U.S. EPA consider finalizing the 

alternative requirement by matching Tier 3 requirements with LEV III through 2024. 

Since Tier 3 allows SVMs to apply for hardship relief under certain conditions, thereby 

addressing their concerns on competing with full line manufacturers, CARB will review 

the Tier 3 SVM requirements when finalized and determine whether alignment between 

LEV III and Tier 3 requirements for SVMs beginning in 2025 is appropriate. 

Independent operational manufacturers are a subset of small volume manufacturers. 

These manufacturers would qualify for small volume manufacturer status, except they
Page 2 

are owned by a larger manufacturer and their sales are currently aggregated with the 

larger manufacturer when determining emission compliance. Both the California and 

federal greenhouse gas programs allow these manufacturers to meet small volume 

manufacturer emission requirements if they can demonstrate that they operate 

completely independently from the owner manufacturer (design and manufacture of 

powertrains, receive no fiscal support from owner manufacturer, etc.). The LEV III 

program extends SVM status to these manufacturers for criteria emission requirements 

and CARB recommends that this manufacturer category be included in the Tier 3 

program. 

Comment 2— Medium-Duty Vehicle Fleet Average Requirement 

Unlike the LEV III program that requires manufacturers to certify a defined percentage 

of their medium-duty vehicles to increasingly stringent emission standards, the 

proposed Tier 3 program imposes a fleet average emission requirement for this class of 

vehicles. Staff has determined that, while different in structure, the LEV III and 

proposed Tier 3 emission requirements for medium-duty vehicles are identical. 

Accordingly, to provide manufacturers with additional flexibility, CARB will propose an 

identical fleet average option for compliance in the LEV III program.
Page 3

Tier 3 Supplemental Federal Test Procedure Requirements 

Comment 1- SFTP Enrichment Limitation Requirement 

CARB supports U.S. EPA's Tier 3 proposal to reduce the tolerance of additional 

enrichment from six to four percent of the air to fuel ratio of Lean Best Torque. CARB 

believes the reduced tolerance is appropriate and feasible due to the improved fuel 

control utilized by today's vehicles. CARB intends to propose alignment with this 

proposal once the Tier 3 program is finalized. 

Comment 2- SFTP Light-Duty Vehicle Interim In-Use Emission Standards 

CARB supports U.S. EPA's proposal to not include relaxed interim emission standards 

for non-methane organic gas (NMOG) + oxides of nitrogen (NOx) and (PM) in the lightduty SFTP program. CARB agrees that the technologies required for the proposed 

SFTP emission standards are well-established .and interim emission standards, typically 

reserved for new technologies, are not need^d. Accordingly, CARB intends to propose 

alignment with this proposal once the Tier 3 program is finalized. 

Comment 3- SFTP Test Requirements for Fuel-Flexible Vehicles 

CARB supports U.S. EPA's Tier 3 proposal to require fuel-flexible vehicles to certify to 

SFTP standards using both gasoline fuel and the highest ethanol content fuel that a 

given vehicle is designed to operate on. CARB believes this proposed requirement 

would ensure that emissions are controlled with all possible fuel blends and will propose 

inclusion of this provision in the LEV III program once the Tier 3 program is finalized. 

Comment 4— Linking of Medium-Duty Vehicle FTP and SFTP Emission Standards 

CARB supports the proposal to require medium-duty vehicles certifying to a Tier 3 ultralow-emission vehicle or super-ultra-low-emission vehicle FTP-equivalent emission 

category to certify to the equivalent SFTP emission category as well. CARB believes 

this requirement is appropriate because the SFTP emission standards were designed to 

be met using the same hardware required to meet the FTP emission standards. 

Accordingly, CARB intends to propose alignment with this proposal once the Tier 3 

program is finalized. 

Comment 5- SFTP Medium-Duty Vehicle Interim In-Use Emission Standards 

CARB supports U.S. EPA's proposal to not include interim in-use emission standards 

for NMOG+NOx and PM in the medium-duty vehicle SFTP program. CARB agrees that 

the technologies required for SFTP compliance are well-established and sufficient lead 

time is provided such that in-use interim emission standards, which are typically
Page 4 

reserved for new technologies, are not needed. Accordingly, CARB intends to propose 

alignment with this proposal once the Tier 3 program is finalized. 

Comment 6- SFTP Light-Duty NMOG+NOx Certification Options 

The LEV III program sets forth a separate option for certifying light-duty vehicles to the 

SFTP NMOG+NOx standards, primarily to accommodate small volume manufacturers. 

While the proposed Tier 3 program does not include an equivalent option, alignment 

between the two programs is not necessary because Tier 3 would accommodate small 

volume manufacturers through a different mechanism. Specifically, Tier 3 would delay 

SFTP compliance for small volume manufacturers until model year 2022. Accordingly, 

CARB does not intend to propose any changes to the LEV III program for this issue.
Page 5 

Comments on Proposed Tier 3 Evaporative Emissions and On-Board


Refueling Vapor Recovery Requirements 

Comment 1- RVP 10 fuel implications for evaporative emission testing 

The NPRM requests comment for alternatively requiring E10 with Reid Vapor Pressure 

(RVP) of 10 psi rather than E15 with an RVP of 9 psi for certification emissions testing. 

Regardless of which fuel U.S. EPA finalizes for Tier 3, CARB strongly recommends that 

U.S. EPA maintain an equivalent level of stringency for evaporative emission testing 

with LEV III evaporative emission standards. If equivalency between Tier 3 and LEV III 

evaporative requirements is maintained, CARB intends to accept test data from vehicles 

tested using Tier 3 certification fuel and temperatures to meet the LEV III evaporative 

emission requirements. See also our more detailed comments on Tier 3 certification 

fuel on pages 21-22 of this document. 

Comment 2- Evaporative leak test 

CARB supports the proposed evaporative leak test and standard, and believes that the 

leak test program will be effective in reducing in-use evaporative emissions. 

Accordingly, CARB intends to propose alignment with this proposal once the Tier 3 

program is finalized. 

Comment 3- Evaporative canister bleed test standard in-use requirement 

CARB supports U.S. EPA's proposal to implement an in-use requirement for the bleed 

test standard. This in-use requirement would ensure that canister performance is 

maintained as vehicles age. Accordingly, CARB intends to propose alignment with this 

proposal once the Tier 3 program is finalized. 

Comment 4- Evaporative emission standards specifically for when an auxiliary 

(non-road) engine is installed in a motor vehicle 

CARB supports U.S. EPA's proposal to extend evaporative emission requirements to 

auxiliary non-road engines installed on motor vehicles. This would provide additional 

control of evaporative emissions. Accordingly, CARB intends to propose alignment with 

this proposal once the Tier 3 program is finalized. 

Comment 5- Evaporative emission requirements for alternative fuels 

The NPRM requests comment on whether the evaporative emission requirements 

should be modified in Tier 3 so that the standards only apply to volatile liquid fuels, 

which would effectively remove evaporative emission requirements for liquefied
Page 6 

petroleum gas and natural gas. CARB recommends that U.S. EPA retain the current 

applicability of the evaporative requirements by continuing to require that liquefied 

petroleum gas and liquefied natural gas vehicles certify to evaporative emission 

standards. CARB currently has an evaporative emission requirement for liquefied 

petroleum gas vehicles. Although existing California evaporative control regulations do 

not specifically include liquefied natural gas, we believe controlling evaporative 

emissions from liquefied natural gas systems is warranted and intend to pursue such 

action in the future. Having an evaporative emission requirement for these vehicles 

assures that system venting does not occur during normal diurnat conditions, and that 

other sources of evaporative emissions are controlled. 

Comment 6- Evaporative emission testing spare tire removal allowance 

The proposed Tier 3 regulatory language (§1066.814) contains an allowance to remove 

the spare tire during evaporative emission testing. This provision conflicts with the text 

in the NPRM that only allows exchanging the vehicle's spare tire with one that has been 

aged. CARB supports the proposed allowance to exchange the spare tire with an aged 

one, but does not agree with allowing spare tire removal. Such an allowance would 

reduce the stringency of the whole vehicle emission standards, which aiready account 

for background emissions, inciuding those from the spare tire. 

Comment 7- Evaporative certification method for heavy-duty vehicles over 14,000 

Ibs. Gross Vehicle Weight Rating 

The NPRM requests comment on a proposal to modify existing certification 

requirements for heavy-duty vehicles over 14,000 Ibs. gross vehicle weight rating so 

that evaporative certifications would rely soleiy on design parameters and engineering 

analysis instead of emissions testing. LEV III test procedures require engineering 

analysis and data to certify vehicles in this weight category for evaporative emissions, 

but do not specifically preclude emission testing as U.S. EPA is suggesting. Because 

some auto manufacturers may prefer to do actual testing, CARB recommends that 

Tier 3 include actual testing as a means of ineeting the evaporative emission 

requirement. Nonetheless, CARB anticipates providing reciprocity to federal 

evaporative emission certification for these vehicles once Tier 3 is finalized. 

Comment 8- Evaporative emission testing reduced canister loading allowance for 

pressurized fuel systems 

The NPRM requests comment on allowing reduced canister loading for a pressurized 

system. This load procedure would be proposed by the auto manufacturer to reflect 

actual diurnal canister loading using the manufacturer's specific technology. CARB is 

concerned that this would reduce the stringency of the test and may result in future 

vehicles that have inadequate ability to purge the canister. The current requirement to
Page 7 

load a canister to breakthrough is a critical part of the evaporative emission test, which 

ensures that enough purge capability is designed into the vehicle to purge a full canister 

during an 11-mile FTP drive cycle. While CARB recognizes that certain engine 

technologies in the future will have reduced purge capabilities, there are already a 

number of strategies available today that could help compensate, such as heated 

purge, optimization of purge strategy to maximize use of available engine vacuum, and 

purge pumps. Accordingly, CARB recommends that the canister loading procedure 

remain as proposed. 

Comment 9- Refueling: Modifying the terms for exemption from the refueling 

requirement for diesel vehicles 

CARB does not support U.S. EPA's proposal to withdraw the condition that the fuel tank 

temperature not exceed 130°F in order for a diesel vehicle to qualify for an exemption 

from the refueling emission requirement absent data showing there would be no 

emission impact. Accordingly, the NPRM should cite any studies supporting such an 

action. While less volatile than gasoline, diesel fuel will still generate vapors; especially 

under higher temperatures. If the original reguaatory language is retained, it would likely 

act to encour,age auto manufacturers to consader heat exposure when designing and 

locating the fuel tank, which would result in reduced refueling emissions. 

Comment 10 - Evaporative option to use design based certification on gaseousfueled vehicles 

Subsequent to adopting evaporative emission standards for gaseous-fueled vehicles, 

U.S. EPA developed designed-based certification procedures for other sources (i.e., for 

marine vessels pursuant to 40 Code of Federal Regulation (CFR) 1060.240). These 

designed-based certification procedures would minimize or eliminate certification 

emission testing. The NPRM requests comment on changing the certification 

requirements for gaseous-fueled vehicles to a design-based approach, which U.S. EPA 

contends would allow for a simpler assessment when certifying these vehicles. CARB 

does not support this approach and believes that testing vehicles is still the most 

effective way to-ensure system integrity and evaporative emission control. Whole 

vehicle testing also ensures that the evaporative system as installed in the vehicle, 

rather than its individual components, is properly evaluated such that the evaporative 

emission targets are met.
Page 8 

Comments on Proposed Tier 3 PM Emission Standards and Test


Procedures 

CARB supports the Tier 3 PM standards proposed by U.S. EPA through the 2024 model 

year. These standards, when fully implemented in 2022, represent a 70 percent 

reduction from current PM standards and will ensure new vehicles and technologies will 

continue to perform at levels achieved by the best of today's vehicle technologies. We 

also agree with U.S. EPA that these standards are readily achievable with no additional 

technology or hardware. 

However, the federal program does not include the LEV III 1 milligram per mile (mg/mi) 

PM standard that phases-in between model years 2025-2028, stating "In order for U.S. 

EPA to propose a standard at this level, there must be established methods to reliably 

and consistently measure PM below that standard, for compliance purposes." While we 

understand U.S. EPA's reluctance at this time due to concerns with current and 

proposed test methods, we encourage U.S. EPA to consider adoption of such a 

standard as discussed below. CARB is in the process of completing testing studies, 

which will show that existing methods can be modified in a straightforward manner to 

achieve accurate and repeatable measurement of sub-1 mg/mi PM emissions. At the 

same time, CARB is also pursuing additional research to explore alternative methods 

for PM measurement in order to take advantage of promising, new commercially 

available real-time instruments. We also urge U.S. EPA to re-examine the proposed 

PM standards for the SFTP for the reasons discussed below. 

CARB adopted the 1 mg/mi PM standard because PM emissions are a particular 

concern for their multiple impacts on public health, air quality, and the global climate. In 

general, mobile sources (mainly cars and trucks) are not major contributors to the 

statewide total PM mass inventory. For instance, the PM emissions from light-duty 

vehicles add up to less than 5 percent of the total California PM 2 5 inventory. However, 

they do contribute significantly to urban pollution and human exposure, such as the 

elevated concentrations of PM near heavily-travelled roadways. Historically, PM 

emissions from diesel engines were of most concern because of their high PM emission 

rates relative to gasoline engines. But as the modern diesel engine achieves 

increasingly lower PM emissions, the interest in and relative contribution of PM 

emissions from an ever increasing number of gasoline-fueled light-duty vehicles is 

growing. Thus, the need for maximum mitigation of PM emissions at the source (i.e., 

tailpipe) using the most technically and economically feasible approach is paramount. 

We have 4 specific comments regarding the PM emissions standards and test 

procedures proposed in the Tier 3 NPRM and the draft Regulatory Impact Analysis. 

The comments are:
Page 9 

Comment 1- Harmonization of 1 mg/mi PM standard between Tier 3 and LEV III 

As stated above, based on studies CARB and others have conducted recently, we 

believe the measurement method will not be an issue for implementing a 1 mg/mi PM 

standard for the 2025 model year or sooner. We agree with U.S. EPA on the statement 

that meeting the 1 mg/mi PM standard requires establishing methods to reliably and 

consistently measure PM below the standard. CARB, U.S. EPA, and some industry 

laboratories have already measured and reported PM emissions from light-duty vehicles 

well below 1 mg/mi using the existing three filter method prescribed by 40 CFR Part 

1065. In its draft Regulatory Impact Analysis, U.S. EPA reported FTP composite PM 

emission results for 16 light-duty passenger cars and trucks (Table 1-8 of the 

Regulatory Impact Analysis}. Reported PM emissions from 11 of the 13 conventional 

port fuel injection vehicles were below 1 mg/mi, ranging from 0.10 to 0.93 mg/mi. With 

the exception of a few repeat results with carriparatively high variability, the data in 

Figure 1-8 of the Regulatory Impact Analysis suggests reasonably good precision and 

repeatability in the vast majority of the tests. 7he reason for the high variability in a few 

results needs investigation, but may be attributed to vehicle stability. Reproducibility 

between different tests cells and/or laboratories also needs to be addressed so that 

consistent results for certification and compliance can be generated within acceptable 

margins. 

CARB has already developed and implemerited a strict laboratory filter handling and 

weighing procedure (MLD 145'} that minimizes variability from the filter weighing 

contribution of PM measurement. The background contribution from the Constant 

Volume Sampler dilution tunnel at CARB facilities has been determined to be no more 

than 2.5 micrograms per filter. The proposed test method in 40 CFR Part 1066 allows 

for a maximum'background correction of 5 micrograms per filter, which is equivalent to 

0.20 mg/mi PM with nominal Constant Volume Sampler flow of 350 standard cubic feet 

per minute and na secondary dilution. Allowance for the correction subtracts most or all 

of the system's contribution to a PM measurement. Therefore, manufacturers can 

design closer to the standard and still have a reasonable probability of passing a one 

test certification requirement. 

CARB also agrees with U.S. EPA's proposed test procedure changes that will allow the 

use of fewer filters when conducting PM measurements. Conceptually, this will reduce 

measurement variability as well as the test burden associated with weighing multiple 

filters. CARB is evaluating the various filter options proposed in 40 CFR Part 1066 and 

develop defined filter test method procedures. We expect the additional options will 

show even further improvement in the capability of the gravimetric technique for 

measurement of PM below 1 mg/mi. 

^ CARB SOP NO. MLD145: PROCEDURE FOR THE DETERMINATION OF PARTICULATE MATTER (PM) MASS 

COLLECTED ON FILTERS. http:l/www.arb.ca.gov/testmeth/slb/sop145v5 1.pdf
Page 10 

Given the progress to date and ongoing work, CARB anticipates that improved test 

procedures, in conjunction with the implementation of strict laboratory filter handing and 

weighing procedures, will allow consistent and reliable gravimetric PM measurement 

well below 1 mg/mi. CARB believes that the automotive industry can make the 

necessary changes to their emission certification laboratories in a timeframe that allows 

for an earlier implementation of the adopted 1 mg/mi standard than the 2025 model 

year. To that point, CARB recommends that U.S. EPA consider adoption of a 1 mg/mi 

PM standard to be consistent with the standards CARB adopted in the LEV III 

regulations, and commit to evaluate in the near future, concurrently with CARB, whether 

the standard could be implemented even earlier than the scheduled 2025 model year 

start date. 

Comment 2- Further evaluation of proposed filter options is needed and 

demonstration of the equivalence among the proposed filter options is critical to 

reduce lab to lab variability	 ' 

The NPRM requests comment on alternative approaches to sampling of PM emissions. 

Specifically, allowing the use of one or two filters during the Urban Dynamometer 

Driving Schedule. Accordingly, the proposed ±est procedures in CFR Part 1066 allow 

the use of fewer filters when conducting PM measurements. As noted above, 

conceptually, the use of fewer filters per test should reduce measurement variability and 

test burden. However, using fewer filters, particularly the one filter option, rnay have 

undesirable adverse impacts for collecting PM mass on filter media. For example, in 

order to comply with the weighting factors specified in the CFR for determining PM 

mass emissions, filter face velocity in the single filter option has to be lowered during 

the cold-start and hot-start phases of the FTP cycle. Lowering the filter face velocity 

could lead to lower PM mass collection on the single filter. Because PN1 emissions are 

the highest during the cold-start phase of the FTP cycle for most internal combustion 

engines, this could end up significantly impacting PM mass collection. 

In addition, a longer sampling time on a single filter, when compared with the 

conventional three filter method, could impact the adsorption and desorption equilibrium 

of semi-volatile organic compounds captured on filter media. Longer sampling times 

might cause either a gain or loss of filter sample mass by adsorbing or stripping away 

organic compounds. The effect of this process could lead to higher variability, 

especially higher lab to lab variability if different filter sampling metl^ods are used. 

Further, if the PM emitted from a vehicle is comprised mainly of volatile and semivolatile organic compounds, the effect could be more unpredictable. 

Establishing correlation arnong the proposed filter options in 40 CFR Part 1066 is 

essential to ensure repeatability and repr-oducibility for vehicle certification and 

compliance testing. Currently there is very limited data avaiiable for evaluating the 

correlation and variability among the proposed fiiter options, especially the single filter
Page 11 

method. Therefore, the proposed filter sampling options need to be fully evaluated and 

correlation criteria need to be established. This is important for reducing lab to lab 

variability for the 3 mg/mi standard, and even more critical for the success of 

implementing the California ^EV III 1 mg/mi PM standard. CARB is committed to 

working with U.S. EPA in conducting a comprehensive evaluation of the proposed filter 

methods, especially the one filter method, to determine the most appropriate method for 

measuring P.M emissions at 1 mglmi levels. 

Comment 3- Set lower PM standards Over the Supplemental Federal Test 

Procedure — US06 Cycle 

The proposed Tier 3 program includes US06 PM standards of 10 mg/mi for lighter 

vehicles and 20 mg/mi for heavier vehicles. E3ased on recent PM emission data 

generated by both CARB and U.S. EPA test programs, CARB believes that a more 

stringent US06 PM standard of 4 mg/mi applicable to both vehicle categories is feasible. 

The following is a summary of these test programs as well as CARB's rationale for the 

recommendation. 

Prior to California's LEV III rulemaking, eight California LEV II-certified light-duty 

vehicles, which included five gasoline direct injection vehicles and three port fuel 

injection vehicles, were tested for PM emissions over the US06 cycle in CARB's 

Naagen-Smit laboratory. Measured PM emissions from seven out of eight vehicles 

were below 3 mg/mi, including all five gasoline direct injection vehicles. A gasoline 

medium-duty passenger vehicle (gross vehicl^e weight rating between 8,501-10,000 Ibs) 

with an odometer reading of approximately 50,000 miles was also tested and achieved 

a US06 PM emission value of 0.8 mg/mi, comparable to those measured from the lightduty test vehicles. One particular light-duty test vehicle had PM emissions in excess of 

3 mg/mi, but CARB suspects tha.t because the vehicle was not designed or certified to a 

stringent US06 PM standard, the calibration strategy may not have been optimized for 

PM control over the US06 and further refinement to the calibration would likely address 

the issue including minimizing any enrichment events that directionally increase 

emissions. 

Recently, U.S. EPA shared PM emission data from its full useful life program with 

CARB. The primary objective of the full useful life program was to establish the 

feasibility of Tier 3 PM standards at vehicle full useful life and investigate the 

contribution of lubricating ,oil to PM emissions in Tier 2 vehicles. More than two dozen 

passenger cars and light-duty trucks were tested for PM.emissions on the FTP and 

US06 cycles. Initial results showed high PM emissions in excess of 40 mg/mi from 

some of the vehicles over the US06 cycle. U.S. EPA later determined that silicone 

contamination from the use. of silicone exhaust transfer tubes in the emission sampling 

system was a major contributor to the measured PM mass emissions, especially on test 

cycles that generate high exhaust tempefatures such as the US06 cycle. As a result,
Page 12 

U.S. EPA re-tested a dozen vehicles and the new data show that all twelve vehicles, 

including a suspected oil burner, emit at levels less than 4 mg/mi PM on the US06 

cycle. 

In response to U.S. EPA's recent US06 testing and the discovery of the silicone 

contamination issue, CARB has initiated a test program to further investigate PM 

emissions on the US06 cycle and determine the feasibility of a more stringent standard. 

The test program aims to gather US06 PM emission data on both current and future 

engine technologies, such as port fuel injection, gasoline direct injection, turbocharging, 

and engine downsizing, and the test vehicles are being selected accordingly. While the 

test program is on-going and vehicles are still being tested, thus far, US06 PM data 

have been collected for eight port fuel injection vehicles, including one light-duty truck, 

and two gasoline direct injection vehicles. PM emissions over the US06 cycle from 

seven out of the ten vehicles were measured below 1 mg/mi while nine out of ten were 

measured below 4 mg/mi. The one vehicle that had PM emissions above 4 mg/mi also 

showed FTP emissions that exceeded the LEV II FTP PM standard, so it is likely that 

the vehicle was not operating within design specifications at the time of testing. 

While the findings of the above test programs clearly show that current LEV II vehicles, 

which are not subject to PM standards under the LEV II SFTP program, are capable of 

complying with a 4 mg/mi US06 PM standard, there have been some concerns 

regarding future technologies, such as advanced gasoline direct injection and 

turbocharged, downsized engines. While these future technologies are expecied to 

increase cylinder pressures and temperatures and possibly the need for additional 

engine temperature control, CARB still believes the 4 mg/mi US06 PM standard is 

feasible. This is because affected Tier 3 vehicles will be equipped with improved PM 

control technologies needed to comply with the 3 mg/mi PM standard on the F^TP (in 

lieu of the 10 mg/mi PM standard that LEV II vehicles are certified to) and because 

additional calibration opportunities will exist as even today's LEV II vehicles, which are 

calibrated without PM control considerations over the US06 cycle, generally have 

emission levels below 4 mg/mi with compliance margin. 

In summary, while CARB will continue to collect US06 PM emission data on future 

technologies, CARB believes the data currently available sufficiently supports a more 

stringent standard and recommends that U.S. EPA adopt a US06 PM standard of 4 

mg/mi in the Tier 3 program. Additionally, should U.S. EPA adopt a more stringent 

standard in the final proposal, CARB recommends that the corresponding in-use 

standards also be lowered in accordance with any changes to the certification 

standards.
Page 13 

Comment 4— Optional Phase-In Formula for FTP and US06 PM Standards 

U.S. EPA is proposing to phase-in Tier 3 FTP and US06 PM emission standards 

beginning with the 2017 model year with 100 percent compliance required in the 2021 

model year. U.S. EPA has also proposed an optional alternative phase-in schedule that 

manufacturers may use to comply with the Tier 3 PM emission standards for these 

model years. This alternative phase-in schedule is based on a mathematical equation 

that provides credits for vehicles certified to the Tier 3 PM standards based on the year 

in which they are certified. Accordingly, vehicles certified to Tier 3 PM standards in 

earlier years would be worth more than those certified in later years. This alternative 

phase-in schedule is similar to one CARB adopted for vehicles meeting the LEV III PM 

standards. However, while the LEV III regulations explicitly state that 100 percent 

compliance is required at the end of the phase-in period, the proposed Tier 3 

regulations do not. We believe that in order to maintain the emission benefits of the Tier 

3 program, it is necessary to add language to the Tier 3 rule to clarify that a 

manufacturer that certifies its vehicles to this alternative phase-in schedule must still 

meet the requirement that 100 percent of those vehicles meet the applicable PM 

standards in the 2021 model year.
Page 14 

Comments on Proposed Tier 3 On-Board Diagnostic Requirements 

Currently U.S. EPA accepts On-Board Diagnostics (OBD) systems certified to CARB's 

OBD II regulation as systems also satisfying the federal OBD regulation. The NPRM 

proposes to codify this practice by adoption and incorporation by reference CARB's 

OBD II regulation (title 13, California Code of Regulations, section 1968.2) as approved 

on June 17, 2010, effective starting in 2017 model year, except for the following 

provisions: 

- sections 1968.2(a), (b), (k) are excluded 

- the tampering clause in section 1968.2(d)(1.4) is excluded 

- the camshaft/crankshaft alignment monitoring requirement in section 

1968.2(e)(15.2.1)(C) would only apply to vehicles with variable valve timing 

systems. 

The proposal also includes a requirement for manufacturers to perform additional 

demonstration testing of the evaporative system monitor capability and to report 

additional standardized data through the OBD system that would identify how many 

miles since the evaporative system leak detection monitor last completed. 

Comment 1— Version of OBD II Regulation Adopted 

Overall, CARB supports U.S. EPA's incorporation of the OBD II regulation section 

1968.2 into the federal requirements. However, CARB adopted additional changes to 

the 2010 version of the OBD II regulation that is referenced in the proposal. 

Specifically, CARB adopted changes which became operative on August 7, 2012. The 

2012 amendments to the OBD II regulation are considered minor and include changes 

to the permanent fault code requirements and in-use monitor performance requirements 

to address issues related to hybrid vehicles (including plug-in hybrid electric vehicles), 

delays to the required start date for three minor diesel-related monitors, and an 

extension to the allowance for particulate matter filter monitors to exclude detection of 

specific failure modes. CARB recommends that U.S. EPA adopt the more recent 

version of the OBD II regulation to be more closely aligned with California. 

Comment 2— Camshaft/crankcase Alignment Monitoring Requirement 

The proposal includes a specific exclusion for the requirement in the CARB OBD II 

regulation section 1968.2(e)(15.2.1)(C) that OBD systems must be able to detect a 

misalignment between the crankshaft and camshaft. This is not a technology-forcing 

requirement and has been in place for many years in California-certified OBD II 

systems. CARB believes that a reduction in diagnostic capability and emission benefit 

would result due to the exclusion of camshaft/crankshaft alignment monitors on vehicles 

without variable valve timing systems, because alignment malfunctions can routinely 

occur in-use due to timing belts slipping or being improperly installed during
Page 15 

maintenance involving timing belt replacement. Therefore, CARB recommends that the 

proposed regulation language be changed by removing the specific section that limits 

camshaft/crankshaft alignment monitoring to only those vehicles equipped with variable 

valve timing systems. 

Comment 3— Evaporative ^eak System Monitor 

The NPRM proposes a requirement for manufacturers to phase-in a 0.020 inch leak 

detection monitor as CARB's OBD II regulation has required since the 2002 model year. 

CARB supports this change to align detection capability nationwide. Further, most 

manufacturers already extend this capability nationwide by certifying a single system 

that meets CARB requirements. 

Further, U.S. EPA is proposing vehicles support and report a new standardized data 

parameter that will be used to indicate the distance traveled since the OBD evaporative 

system leak monitor was last completed successfully, if the system passed or failed 

during the monitoring event, and to store this data in non-volatile memory such that it 

can survive battery disconnects and on-board computer memory clear events. This 

proposed requirement is intend"ed to determine'whether off-board leak detection testing 

needs to be performed on individual vehicles during the In-Use Verification Testing 

(IUVP) program. 

Concerning the^proposal for a`new standar •dized data parameter, CARB has worked 

with the SAE J1979 committee to develop ari updated standard to achieve this. 

However, the draft SAE proposal created to meet the intent does not completely align 

with the U.S. EPA proposed regulatory language. Specifically, it does not provide for 

the data to be stored in non-volatile memory but'instead has the value report a clear 

indication if the data has been erased and the monitor has not successfully run since 

then. In this situation, it appears to CARB that this will satisfy the intent and provide a 

clear indication that the off-board leak test should be performed on such a vehicle 

selected for IUVP testing. Secondly, the draft parameter indicates the mileage since the 

last successful test completion but does not directly indicate whether it was a pass or 

fail decision. Instead, current fault code status must be used and the absence (or 

presence) of an evaporative system leak fault code will confirm whether the monitor last 

ran and passed (or failed, respectively). Again, CARB believes this will provide the 

necessary data for the intended use in IUVP testing. Accordingly, CARB recommends 

the proposed language be modified in the final proposal to eliminate the requirement 

that the new data be able to survive battery disconnects and computer memory clear 

events as well as remove the requirement that the new parameter directly report 

whether the last monitoring event was a pass or a faiL
Page 16 

Comment 4— Evaporative System Activated Carbon Canister Monitor and Purge 

Monitor 

Though not officially part of U.S. EPA's proposal, U.S. EPA seeks comments about a 

provision to require the OBD system to monitor the activated carbon canister, 

specifically for evidence of proper performance of the canister such as adequate 

adsorption and desorption of hydrocarbon vapors. U.S. EPA believes such 

performance could be sensed with existing hardware on the vehicle (e.g., looking for 

changes in canister carbon bed temperature or presence of vapor in the fuel going to 

the intake manifold after a cold start or refueling event). U.S. EPA also seeks comment 

on whether any device used to enhance or control purge flows, rates, or schedules 

(e.g., a vacuum pump or similar device used to assist vehicle engine vacuum purge} 

should be monitored by the OBD system. 

CARB currently has no requirement for monitoring the canister performance but given 

the increasing importance of keeping evaporative emissions to a minimum, believes the 

idea merits further exploration and research before making any decisions on 

implementing any regulation changes. Important aspects that would likely need to be 

investigated include whether monitoring of the activated carbon canister can indeed be 

robustly done with the existing hardware on the vehicle. Regarding devices used to 

assist purge flow, increased usage of such devices in the future is possible, so further 

investigation into monitoring of these devices is warranted. However, CARB believes 

the OBD regulation already covers monitoring of these devices to some extent, since 

they would be considered evaporative system components and consequently required 

to be monitored under comprehensive components requirements for proper function. 

Comment 5— Pressurized Fuel Tank Monitor 

EPA also seeks comments about a provision regarding pressurized and sealed fuel 

tanks. Based on its observation of a trend towards fuel tanks with higher operating 

pressures or tanks sealed to the atmosphere during normal operation and data showing 

a leak in these systems will result in substantially higher emissions relative to traditional 

low pressure systems, U.S. EPA seeks comment on the feasibility and cost of requiring 

OBD leak detection monitors to detect a smaller diameter orifice on such systems — 

specifically, something in the magnitude of a 0.010 inch leak in lieu of a 0.020 inch leak 

anywhere in the evaporative system. This would apply to vehicles with a designed inuse operating pressure in excess of 0.36 psi (10 inches of water). For sealed tanks, 

U.S. EPA seeks comments on an added requirement that any valve that isolates the 

fuel tank vapor from the canister be defaulted to an open position at key off (allowing 

vapors to vent to the canister) if the OBD monitor detects a leak and illuminates the 

malfunction indicator light. Further, for pressurized systems, U.S. EPA is asking for 

comment on setting the evaporative system monitor threshold in the 0.010 inch to 0.015 

inch range, specifically asking for the feasibility of this threshold, the effects of the vent
Page 17 

valve open requirement on on-board refueling vapor recovery, and the reparability of 

leaks below 0.020 inch. 

CARB currently has no such requirements but given the increasing importance of 

keeping evaporative emissions to a minimum, believes the ideas merit further 

exploration and research before making any decisions on implementing any regulation 

changes. Important aspects that would likely need to be investigated include the 

feasibility of the repair service community to efficiently diagnose and repair detected 

leaks with a smaller diameter.
Page 18 

Comments on Proposed Tier 3 In-Use Verification Program 

The NPRM proposes additional measures to identify evaporative leaks on in-use 

vehicles based on studies performed by the Coordinating Research Council and 

Colorado Department of Public Health and Environment. Specifically, the NPRM 

proposes adding a test procedure to the IUVP focused on testing a broader sample of 

fuel/evaporative systems leaks in in-use vehicles. Moreover, the NPRM proposes the 

addition of an IUVP evaporative leak check requirement beginning with 2018 model 

year vehicles. This requirement would be included in the IUVP's low and high mileage 

tests for any volatile fuel powered vehicle (except diesel and natural gas) with a 

requirement that there be at least one representative vehicle for each 

evaporative/refueling/leak family evaluated at each year point. EPA is proposing this 

approach in lieu of creating a new set of requirements which would require a separate 

set of vehicles to be procured for testing. In addition, the NPRM is considering 

extending the age point for leak emission testing for IUVP beyond the current four year 

test point (e.g., testing vehicles six to eight years old) to better assess aged vehicles for 

evaporative leaks. 

In response to reduced fuel sulfur levels in California and federal commercial gasoline, 

use of a sulfur purge preconditioning to reduce catalyst sulfur deposits prior to IUVP 

emission testing was disallowed by both CARB and U.S. EPA beginning in 2007. 

These purge procedures, which consist of high speed driving cycles not normally 

experienced as typical driving patterns, are designed to reduce sulfur and carbon 

deposits in the catalytic converter. Decreasing carbon build deposition in the exhaust 

system may have a positive impact on emissions but because carbon deposits are a 

result of real world driving conditions and fuel use, use of a sulfur purge procedure may 

produce a false representation of true in-use emissions. Nonetheless, the NPRM 

proposes to allow for conducting a sulfur purge cycle over the US06 test cycle for those 

manufacturers requiring a sulfur preconditioning test. 

Comment 1- In-Use Verification Program Evaporative Leak Check 

U.S. EPA is also proposing to conduct an evaporative leak test on vehicles that are 6 to 

8 years old. Although this is doable for IUVP, the challenge will occur if enough 

vehicles fail the leak check for a given test group and the manufacturer must then 

conduct an In-Use Confirmatory Program. Under an In-Use Confirmatory Program, the 

manufacturer must procure ten properly maintained and used vehicles which creates a 

challenge because many of these vehicles will be out of warranty, sold to a second 

owner and/or operated beyond 75 percent of the certified useful life and may not be 

properly maintained. Accordingly, CARB recommends that U.S. EPA include language 

to require testing on vehicles no more than 6 years after the certified model year and 

within 75 percent of the useful life mileage. For example, a manufacturer would be
Page 19 

required to conduct evaporative leak testing on 2015 MY vehicles within 75 percent of 

the useful life mileage and before the end of the 2021 calendar year. 

Comment 2- In-Use Verification Program Sulfur Purge Procedure for Sulfur 

Preconditioning. 

As noted above, sulfur content of federal commercial fuel has been significantly reduced 

and, based on past IUVP test data, manufacturers have not been allowed to perform 

sulfur purge cycles since 2007 and have not experienced any test vehicles failing to 

meet the exhaust emission standards that were attributed to high sulfur deposits. 

CARB believes running additional sulfur cleariout procedures is unnecessary and 

should not be included as part of the IUVP or any in-use confirmatory test program. 

^ f .	.
Page 20

Comments on Proposed Tier 3 F'uel Standards 

CARB staff strongly supports the proposed Tier 3 gasoline sulfur standards and 

applauds the efforts of U.S. EPA staff for bringing our fuel programs in alignment. 

CARB staff also supports the proposed requirements for midlevel ethanol blends, as 

well as promoting the powerplant design advantages of an E30 blend. CARB staff 

offers the following comments in support of the proposed gasoline sulfur standards and 

to further harmonize fuel program requirements of the two agencies. 

Comment 1— Gasoline Sulfur Standards 

U.S. EPA is proposing to lower the sulfur standard in gasoline and ethanol-gasoline 

blends to a 10 parts per million (ppm) annual average. California's gasoline already 

meets the proposed 10 ppm sulfur standard. For many years California has led the 

nation in gasoline quality, including a low-sulfur standard. On December 31, 2003, 

California lowered the sulfur cap on gasoline from 80 ppm to 60 ppm. Then on 

December 31, 2005, the sulfur cap was lowered from 60 ppm to 30 ppm. And finally, on 

December 31, 2011, the sulfur cap was lowered to 20 ppm. The 20 ppm sulfur cap 

brought the in-use fuel's sulfur average in California to about 9 ppm. 

Sulfur reduction has been one of the most cost--effective changes that have been made 

to California's gasoline. California's low-sulfur gasoline has reduced emissions by 

approximately 400 tons per day (tpd) of hydrocarbon emissions, 129 tpd of oxides of 

nitrogen emission (NOx), 34 tpd of oxides of sulfur emissions, and 1300 tpd of carbon 

monoxide emissions3 . Fuel/vehicle emission studies used in the development of 

California's Predictive Model have shown that lower sulfur in gasoline results in lower 

NOx emissions, lower exhaust tailpipe hydrocarbon emissions, and lower toxics 

emissions4 . In addition, low sulfur reduces potential catalyst deactivation from sulfur 

contamination in vehicle emission control systems. 

CARB staff estimates that California's reformulated gasoline (CaRFG) program cost 

about 2 to 5 cents per gallon. Of that, staff estimates costs as low as 0.6 cents per 

gallon being attributable to lowering sulfur in CaRFG. Accordingly, the Tier 3 gasoline 

sulfur standard's estimated cost of 0.89 cents per gallon is in line with California's 

estimated cost of lowering sulfur. 

In conclusion, CARB staff believes that U.S. EPA's Tier 3 gasoline sulfur standards will 

provide cost-effective emission reductions. CARB staff strongly supports U.S. EPA's 

Tier 3 gasoline sulfur standards and applauds the efforts of U.S. EPA's staff for bringing 

our gasoline fuel programs into alignment. 

2 http://www.arb.ca.govlreqact/2012/Ieviiiqhg2012/levisor_pdf

3 http:!/www.arb.ca.gov/board/books12007/022207!07-2-2pres.pdf

4 http://www.arb.ca.gov/fuels/gasoline/premodellpmdevelop.htm
Page 21 

Comments on Proposed Tier 3 Certification Test Fuel Specifications 

CARB staff disagrees with U.S. EPA's decision to propose 15 percent by volume 

ethanol gasoline (E15) as the Tier 3 certification test fuel. Additionally, CARB 

recommends reciprocity with California's gasoline certification fuel beyond 2020 and 

throughout the lifetime of the Tier 3 program. CARB offers the following comments in 

support of our recommendation in an effort to further harmonize certification fuel 

program requirements of the two agencies. 

Comment 1— Gasoline Certification Test Fuel 

CARB recommends that the U.S. EPA reconsider the use of E15 as the Tier 3 

certification fuel. Instead, CARB recommends a certification fuel with 10 percent 

volume ethanol (E10) and a 9.0 pounds per square inch (psi) RVP. An E10 certification 

fuel would be.consistent with the current federal commercial fuel. In addition, the 9.0 

psi RVP vvould allow the Tier 3 program and California's LEV III program to be 

consistent with the certification fuel reciprocity precedent set between the Tier 2 

program and California's LEV II program. The evaporative emission difference between 

U.S. EPA's 9.0 psi RVP Tier 2 certification fuet,and California's LEV II 7.0 psi RVP 

certification fuel was offset by U.S. EPA's use of a lower diurnal temperature range. 

California's LEV III certification fuel has approximately a 7.0 psi RVP and CARB staff 

recommends that U.S. EPA maintain a 9; 0 psi RVP fuel such that the evaporative 

emission offssts between the California LEV lll certification fuel and the Tier 3 

certification fuel can be maintained. 

E15 is currently used in a handful of fueling stations nationwide and its further 

penetration into the marketplace is uncertain. Given the practical considerations 

inherent in providing a refueling infrastructure for E15, it may not proliferate very rapidly 

into the marketplace. On the other hand, E10 has been tested thoroughly as a viable 

fuel for all vehicles currently on the road and, as a result, will likely be widely used for 

the foreseeable future. However, should E15 constitute a significant fraction of the 

federal commercial fuel market at some future date, it would be appropriate at that time 

for U.S. EPA to reconsider the composition of Tier 3 certification fuel. 

Comment 2— Certification Fuel Reciprocity 

As proposed, Tier 3 provides reciprocity for certification fuel between the LEV III and 

Tier 3 programs until model year 2020, at which time U.S. EPA will only recognize 

emission certification on federal certification fuel. Traditionally, the two agencies have 

granted reciprocity for certification fuel when demonstrating emission compliance, thus 

providing a degree of compliance flexibility to vehicle manufacturers without impacting 

the emission benefits of the California or federal programs. CARB believes this should 

continue to hold true whether Tier 3 certification fuel is E15 as currently proposed or
Page 22 

E10 (see our previous comment though on the impact of an RVP of 10 on reciprocity 

concerns for evaporative emission testing) and strongly recommends continuing the 

practice of providing reciprocity for certification fuel in the Tier 3 program beyond 2020 

and throughout the lifetime of the Tier 3 program.
Page 23 

Comments on Costs and Economic Impacts of Tier 3 Proposal 

CARB staff supports the approach used to evaluate the economic impacts of U.S. 

EPA's Tier 3 proposal. 

Due to the differences in regulatory scope, timeframes, and geography, a direct 

comparison to CARB's LEV III economic impact analysis is incompatible. Nowever, 

given that the proposal's compliance costs and cost-effectiveness metrics are on the 

same order of magnitude as those estimated by CARB in previous related rulemakings, 

CARB staff concurs with U.S. EPA's overall conclusions on the direction and magnitude 

of economic impacts to the auto and refinery sectors. However, some time has passed 

since the initial evaluation of technology costs detailed in the draft Regulatory Impact 

Analysis. Therefore, it may be appropriate for U.S. EPA to revisit those costs estimates 

to determine if any revisions are warranted. 

While health and other ancillary benefits were not formally quantified in CARB's most 

recent LEV III rulemaking, in the past CARB has used a similar method to the one 

employed in the proposal for monetizing health benefits. Additionally, we believe that 

given the magnitude of compliance costs relative to the size of the domestic economy, 

U.S. EPA's more qualitative approach for estimating employment effects using the 

Morgenstern et al. framework instead of relying on economy-wide modeling is 

reasonable.
Page 24 

Comments on Subpart L--Methods for Unregulated and Special 


Pollutants 

CARB supports U.S. EPA's attempt to quantify the semi-volatile organic compound 

(SVOC) emissions from gasoline vehicle exhaust. There is a need to understand if 

advanced combustion and emission control technologies targeting criteria and 

greenhouse gas pollutants also lead to SVOC reduction. However, CARB has several 

concerns that require U.S. EPA clarification. CARB believes U.S. EPA should modify its 

definition of SVOCs. CARB recommends that U.S. EPA align the SVOC sampling 

method with the PM gravimetric determination if it is used for certification and 

compliance. In addition, the proposed SVOC sampling media and extraction procedure 

are tightly specified. U.S. EPA should allow flexibility or alternatives. Given that target 

analytes, analytical methods, and data reporting are not specified in the NPRM, our 

ability to comment is limited. 

Comment 1 - SVOC de^nition, §1065.1103(e)(3) 

The U.S. EPA states that "Most SVOCs have at least 14 carbon atoms per molecule 

and have a boiling point between 240°C and 400°C.....". 

This statement suggests that U.S. EPA's operational definition of semi-volatile 

compounds would exclude C10 —C13 polynuclear aromatic hydrocarbons (PAH) which 

are known to be semi-volatile in nature. Therefore we suggest that U.S. EPA rephrase 

this statement as follows: "Most SVOCs have at least 14 carbon atoms per molecule or 

have a boiling point between 240°C and 400°C.....". 

Comment 2- SVOC sampling modules storage, §1065.1103(b) 

The NPRM recommends "Blank sorbent modules with inlet and outlet covered (i.e., field 

blanks) should periodically accompany the test sample train throughout the course of a 

test, including the sample train and sorbent module disassembly, sample packaging, 

and storage". 

CARB suggests U.S. EPA revise this to read "Blank sorbent modules (i.e. field blanks) 

should be stored in a sealed environment and should periodically accompany the test 

train...". CARB believes the term "cover" is too vague for sorbent modules as the 

sample collection is a passive diffusive mechanism; depending on how the sample 

module is "covered" the blank level can vary and may not provide the information 

needed for field blanks. U.S. EPA should also allow the flexibility of designing a custom 

SVOC sampler or sorbent module.
Page 25 

Comment 3- SVOC sampling system design, §1065.1105 

The NPRM recommends SVOC sampling from undiluted emissions to minimize the 

amount of SVOC's lost and recommends using a heated sample probe with a set point 

no higher than 200°C. 

CARB agrees that sampling SVOC directly from the emission source may reduce the 

SVOC loss in the dilution system. However, the temperature of undiluted exhaust is 

usually higher than the temperature specified for PM mass gravimetric determination 

(47±5°C). Therefore, the gas-particle partition of SVOC will favor the gas phase and the 

partition will not be consistent with the determination of PM mass. CARB believes that 

the specified 200°C setting is logically in conflict with the U.S. EPA statement that 

SVOCs typically have boiling points starting at 240°C. U.S. EPA should clarify the 

rationale and goals for the 200°C setting. 

Comment 4- SVOC sampling media selection, §1065.1105(c ) 

The NPRM recommends using 110 mm or 293 mm "pure" quartz filter and 40 g XAD-2 

at an average flow rate of 70 Umin for SVOC sampling. 

CARB believes U.S. EPA should allow flexibility in sample media selection if equivalent 

performance can be demonstrated. Based on'CARB's experience, a 47mm Teflon 

coated glass fiber filter followed by 7g of XAD-4 sandwiched with PUF shows no 

breakthrough of PANs when used for diluted exhaust sampling. Furfhermore it's not 

clear whether the integrity of the quartz fiber ^ilter is maintained and can be used for 

sampling after cleaning with the Soxhlet method. A more appropriate cleaning 

procedure for quartz fiber filters should include baking in the oven to remove 

carbonaceous components. 

Comment 5—SVOC sample recovery method, §1065.1109 (a)(2)-(4) 

The NPRM recommends a method to recover the potential SVOC lost in the sampling 

probe, transfer line, and/or filter holder with solvent. 

CARB believes that this recovery process will result in higher uncertainty when 

quantifying SVOCs at low emission levels due to several factors including: the impurities 

in the large volume of solvent used for recovery, contamination from the environment 

where the recovery is conducted, and the variability of the recovery operation. The 

proposed recovery process will also extend vehicle testing time. Therefore, U.S. EPA 

should specify the frequency of conducting sample train recovery.
Page 26 

Comment 6- SVOC isotopically labeled standards spiking procedure, §1065.1107 

(C) 

The NPRM language for determining the extraction efficiency of SVOC adsorbed to the 

sample media using isotopically labeled standards (surrogate standard) is not clear. 

CARB believes that when these standards are spiked before sampling is carried out, the 

recovered surrogate standards account for both the potential losses/gain during 

sampling as well as in the extraction process (sample analysis). Uncertainties are also 

introduced when a 60 minute waiting period is required for solvent evaporation. CARB 

recommends U.S. EPA clarify how this surrogate standard will be used as well as the 

use of the recovery standard used in analyses (§1065.1111) which determine the 

extraction efficiency of the analytical methods. 

Comment 7- SVOC sample extraction, §1065.1109(b) 

The NPRM describes detailed sample media cleaning and sample extraction 

procedures with the Soxhlet extraction method. 

CARB believes that U.S. EPA should allow alternative methods if they demonstrate 

equivalent performance in terms of cleaning and extraction efficiency compared to the 

Soxhlet method. CARB MLD SOP#144 uses the Dionex Automated Solvent Extractor 

(ASE) to extract SVOC samples. The ASE shortens sample preparation time and 

reduces labor cost, and can be considered as an acceptable alternative to the Soxhlet 

method. In addition, CARB believes the proposed method should also allow the filter 

and XAD-2 to be extracted either separately or combined, depending on the data need.
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