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OAR Box 1830 

Prepped by Ollie Stewart 

Document Number: 

234) IV-C-195 

Docket Number: 

A-87-11 

Printed 11/13/2008 9:00:23 AM Sheet 234 of 236 
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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

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NOV 6 1993 

Honorable John D. Dingell 

Chairman, Subcommittee on 

Oversight and Investigations 

Committee on Energy and Commerce 

U.S. House of Representatives 

Washington, D.C. 20515 

Dear Mr. Chairman: 

This is in response to your letter of August 4, 1993 

regarding onboard refueling vapor recovery (ORVR). I would first 

like to respond briefly to the three points raised in the first 

portion of the statement enclosed with your letter; replies to 

your specific questions are contained in the enclosure to this 

letter. 

First, with regard to the financial status of the automobile 

industry, the Environmental Protection Agency (EPA) always has% 

and will continue to consider the financial health of the | 

automobile industry in its regulatory activities. It is a key 

consideration in providing compliance flexibility where possible 

and appropriate. Balancing cost impacts and environmental 

benefits is always an important consideration in regulatory 

decisions. In that same vein, as EPA develops the final ORVR 

rule we will complete a detailed assessment of costs that would 

be incurred by both industry and the nation as a whole, and will 

strive to design the most flexible, efficient and cost effective 

-program possible. 

Another point discussed in the first portion of your letter 

refers to the applicability of the ORVR requirement to light-duty 

trucks (LDTs;|, tiea^-dtity vehicles (HDVs), and vehicles powered 

by fuels <^|j>£y£ -fj^n^gksdline. We note your comments regarding 

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assessment, we need to thoroughly evaluate the costs and benefits 

of ORVR controls for LDTs and HDVs including the impacts of the 

Stage II controls in place and the other benefits of refueling 

controls. Your comments will be carefully considered as we 

develop the final rule. 

With regard to applying these requirements to vehicles 

powered by fuels other than gasoline as indicated by section 

202(a)(6), we have tried where possible to create a level playing 

field in the marketplace for all fuels and in this regard to 

apply our emission standards to all fuels equally. This approach 

also provides manufacturers information on emission control 

requirements early so that compliance can be considered in their 

product planning. As a practical matter, fuels such as diesel, 

liquid petroleum gas (LPG), and natural gas have very low 

refueling emissions and vehicles using these fuels are expected 

to demonstrate compliance without a control system. 

We are now analyzing comments on the fuel applicability 

issues and have not yet made a final decision. 

Your third point deals with the issue of vehicle safety. As 

was mentioned in your letter, EPA and representatives of the auto 

industry held technical discussions regarding the relationship 

between the proposed refueling test procedure(s) and the revised 

test procedure contained in the recently promulgated evaporative 

emissions rule. What emerged from those discussions was one 

option, among several we are considering, which the manufacturers 

claimed would permit them to use an integrated refueling/ 

evaporative emissions control system (including a single canister 

to capture both refueling and evaporative emissions) as well as a 

liquid seal in lieu of a mechanical seal in the fillneck. 

This option appears to address many of the safety concerns 

raised previously by the manufacturers and others regarding the 

potential affects of ORVR controls on fuel system complexity and 

the need for additional vapor storage. Written comments provided 

by the auto manufacturers indicate that these test procedure 

changes, if implemented, will address their longstanding concerns 

about ORVR safety. EPA must consider seriously any test 

procedure option which gets the required level of emissions 

control and also addresses the manufacturers' concerns about 

vehicle safety. The National Highway Traffic Safety 

Administration (NHTSA) staff have been thoroughly briefed on the 

matter. They are now conducting their own independent assessment 

of the vehicle safety implications of the proposed test procedure 

changes. 

Part II of your letter addresses specific questions to the 

Agency regarding ORVR. You will find the Agency's response to 

these questions in the enclosure to this letter.* 
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In closing, let me assure you of our commitment to fully 

analyze all aspects of the decisions in the ORVR rulemaking and 

to coordinate with NHTSA. As you requested, your letter and this 

response will be placed in the public docket for this rule. 

Sincerely, 

Carol M. Browner 

Enclosure 
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Enclosure 

Response to Specific Questions 

1. Alternate ORVR Technologies 

The vehicle manufacturers have indicated from the outset 

that their intent was to use canister-based ORVR systems. Nearly 

all published developmental work on ORVR control systems has been 

on canister-based systems, and therefore the bulk of the analysis 

is built on the likely use of this control approach. 

However, EPA recognizes that potential alternate control 

strategies exist. Bladders are used in race cars and aircraft, 

but they serve primarily as a fuel containment device to prevent 

fuel spillage in the event of fuel tank damage. Often, these 

bladders are of heavier construction than what would be necessary 

for adequate prevention of vapor generation. 

As part of the rulemaking, EPA received several comments on 

the availability and status of potential alternate control 

strategies. Based on the information now available, there is 

doubt as to whether these technologies could or would be used 

within the timeframe now contemplated for the introduction of 

ORVR controls. In the final rule, EPA plans to include an 

assessment of the development status of these alternate ORVR 

control systems and whether such systems would be feasible or 

available for 1998. 

2. Refueling Emissions from LDTs and HDVs 

In your question, you request justification of the statement 

that light-duty trucks (LDTs) account for one-third of the total 

refueling emissions and heavy-duty vehicles (HDVs) for another 

five percent. EPA conducted an analysis to assess the amount of 

gasoline currently used by LDTs and HDVs. The estimate was drawn 

primarily from EPA's M0BILE4.1 Fuel Consumption Model which 

projects vehicle registrations, miles travelled and fuel 

efficiency to determine the fuel consumption of certain vehicle 

classes in the overall motor vehicle fleet. Other sources such 

as Department of Energy (DoE) publications were consulted as 

well. 
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The total annual refueling emission inventory for cars and 

trucks nationwide is presented in the following table: 

1990 Refueling Emissions 

Vehicle Type 

LDVs 

LDTs 

HDVs 

Total: 

Fuel Consumption, 

Nationwide (10 

gal.) 

68.75 (62.7%) 

33.75 (30.8%) 

7.2 (6.5%) 

109.7 

Emissions, 

Nationwide (1000 

Metric Tons) 

302 

151 

32 

485 

Analysis conducted for 1990 indicates that refueling 

emissions account for approximately 4 percent of the highway 

mobile sources VOC inventory and thus about one to two percent of 

the entire VOC inventory. Clearly the relative contribution will 

vary over time with factors such as growth in the number of 

sources, vehicle miles travelled, and a phase-in of various 

emission control programs. The relative contribution of LDTs and 

HDVs will increase if the recent trend in sales increases in 

these classes of vehicles continues or LDV fuel economy improves. 

Percentage-wise these estimates will vary somewhat from 

nonattainment area to nonattainment area depending on area 

specific factors and on environmental conditions, fuel and fleet 

characteristics, and the mix of mobile and stationary sources. 

3. Refueling Emissions from Alternative-Fuel Vehicles 

Based on current information we do not expect refueling 

emissions from alternative fuel vehicles to present a problem. 

In most cases, the refueling emissions from non-gasoline fuels 

are much less than for gasoline. Given the nature of these fuels 

and the fuel systems, we expect that many non-gasoline/ 

alternative-fuel vehicles will be able to comply with the ORVR 

standard without additional control hardware (such as those that 

operate on diesel, electricity, natural gas, and LPG). However, 

this does not necessarily diminish the need to apply the ORVR 

requirement to these vehicles. For example, a well designed 

refueling system for a compressed natural gas (CNG) vehicle would 

have near zero refueling emissions if the vehicle/refueling line 

interface takes into account the need to control refueling 

emissions. Absent the use of a refueling approach, such as a 
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dry-coupling, refueling emissions could be greater than necessary 

for an otherwise clean vehicle technology. Thus, the presence of 

an ORVR standard will help to assure the use of readily available 

refueling hardware for alternative fueled vehicles. 

4. Analyses of Safety Issues for ORVR Controls for Non-Gasoline 

Fueled Vehicles 

As was mentioned above most non-gasoline fuel vehicles are 

not likely to require additional control systems and thus should 

have no added safety implications due to the ORVR requirements. 

Several fuels (such as M85 and E85) are expected to use 

technology similar to gasoline-fueled vehicles. At this point we 

are not aware of any unique safety issues which would apply to 

these vehicles. Given the significance of vehicle safety 

concerns, should such issues arise as these technologies develop, 

they would receive careful consideration. 

5. Consultation with DOE regarding ORVR in Light of the Energy 

Policy Act and Executive Order Alternative-Fuel Vehicle 

Programs 

EPA maintains a continuing dialogue with the Department of 

Energy (DoE) regarding alternative fuel vehicles (AFVs). As part 

of our coordination under the Clean Fuel Fleet provisions of 

Section 246 of the CAA, a major focus of our discussion with DoE 

centered on "the development of a program to integrate AFVs into 

the federal vehicle emission control program. As was discussed 

in my recent letter regarding Inherently Low Emission Vehicles, 

the inherently low nature of the vapor emissions from many 

alternative-fuel vehicles was a key point in the vehicle/fuel 

technology deliberations which occurred with DoE and others as 

part of the discussions of the Federal Fleet Conversion Task 

Force. However, since we expect that most of these vehicles will 

not need additional control hardware to pass a refueling emission 

standard, the ORVR requirement was not an issue. 

6. Fifty State Standard and California's S209 Waiver 

EPA originally proposed that the onboard requirement would 

apply to vehicles sold in all 50 states. However, in early 

January 1993 the state of California was issued a waiver under 

Section 209 of the Clean Air Act for its Low Emission Vehicle 

Program. At that time an onboard requirement was not under 

consideration by EPA, and control of refueling emissions was not 

considered in the waiver decision. As was stated in the May 1993 

Federal Register notice, the issue of whether California 

standards satisfy the criteria of Section 209 is not part of the 

on-board rulemaking, but rather would be considered in a section 

209 waiver proceeding, with consideration of leadtime and other 

factors. 58FR AT 30733 (May 27, 1993). 
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7. Statutory Deadline and Trucks 

The 1990 CAA Amendments call for the LDV ORVR requirement to 

be implemented four model years after the model year in which the 

standard is promulgated with a three year phase-in: 40, 80, and 

100 percent. As we now conceive the program, the phase-in would 

begin in the 1998 model year and full phase-in would be required 

by the 2000 model year. EPA's new evaporative emission rules, 

which apply to LDVs, LDTs, and HDVs, are to be implemented on a 

similar but not identical time line. Phase-in would begin with 

1996 models at 20 percent, with 40 percent in 1997, 90 percent in 

1998, and concluding at 100 percent in 1999. Recognizing there 

may be benefits to be gained by manufacturers by conforming the 

phase-in schedules of LDVs, LDTs, and HDVs, EPA has proposed and 

requested comment on treating LDTs and HDVs the same as LDVs for 

purposes of leadtime and phase-in under the ORVR requirement. As 

you note, the proposal to apply ORVR to LDTs and HDVs is being 

handled under EPA's discretionary authority. Whether this 

leadtime/phase-in schedule is appropriate or some adjustments are 

needed remains an open issue. 

The timing relationship between the evaporative and ORVR 

requirements is important because the test procedure option 

favored by the manufacturers could be applied to all three 

vehicle classes. Thus, the possibility of integrated 

evaporative/refueling control system designs would be available 

to all three classes and thus the obstacles to implementing ORVR 

for LDTs/HDVs would be minimized. 

Although cars and trucks are not identical, in many respects 

they are very similar. Specifically, the fuel and fuel vapor 

control systems on LDVs and LDTs are very similar. Ranges in 

fuel tank sizes overlap and fuel system configurations are 

similar. Some vehicle types employ identical parts, such as 

rollover valves, canisters, vent lines, purge valves. Both LDVs 

and LDTs are evaluated over the same test procedures, and are 

subject to the same fuel system safety standards. 

Also, as was mentioned above, the test procedure option 

favored by the manufacturers can be applied to LDTs and HDVs thus 

allowing the control system to be sized and designed consistent 

with evaporative control system requirements. Changes will 

mainly involve a larger diameter vapor vent line and a fillneck 

seal. However, there are some trucks with unique characteristics 

and those will require careful consideration as we formulate the 

options for the final rule. 
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8. Ninetv-five Percent Control Efficiency 

You assert in your letter that the May 27 notice reopening 

the comment period appears to reguire control efficiency beyond 

the 95 percent mandated by the Clean Air Act. I would note that 

the Act requires a minimum of 95 percent control, not a maximum 

of 95 percent and in the May notice EPA presented a range for the 

standard which would entail 95 to 98 percent control during test 

procedure conditions. 

Emphasis is given to the importance of test procedure 

conditions because of the nature of the expected control 

technology. It is important to note that canisters are not 

proportional control devices. They provide very efficient 

control up to their design capacity, but after this capacity is 

exhausted very high emission levels will occur. Given this 

characteristic of the control technology, assuring a high level 

of in-use efficiency during the ozone season it is appropriate to 

consider setting the test procedure parameters (fuel, vapor 

pressure and temperatures, etc.) near worst-case levels. The 

parameters specified in EPA's proposed test procedures reflect 

these factors and, if adopted in final regulations, ORVR systems 

would be designed to assure in-use control under most in-use 

conditions. 

Thus, the focus of the stringency issue is not only on the 

numerical level of the standard, but also on the effectiveness of 

the system in-use. Given the large number of variables, 

predicting in-use effectiveness is difficult. However, both test 

procedure specifications and the emission standard need to be set 

to achieve a high level of control in the ozone season with due 

regard to safety, cost and cost effectiveness issues. 

If required, LDTs and HDVs would also be expected to use 

control system approaches similar to LDVs and refueling emission 

rates are primarily determined by fuel temperatures and vapor 

pressures rather than vehicle specific factors. Thus, it is 

reasonable that the emission standard and requirements for LDTs 

and HDVs could be the same as for LDVs. A small variation up or 

down in the level of the standard for these vehicles would not 

have a significant effect on the control system design. 

Furthermore, the test procedure option favored by the 

manufacturers relaxes the test conditions somewhat compared to 

other options contained in the May 1993 notice and the 1987 NPRM. 

We have received comments which claim that the test procedure 

option favored by the manufacturers would not achieve 95 percent 

control in use, and we are now assessing these comments as part 

of the final rule decision making process regarding the test 

procedure. 
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9. Safety Analysis Prior to Certification 

EPA agrees that it is preferable to resolve all safety 

issues prior to promulgation of the final rule if possible. 

Based on the comments provided by the manufacturers, it appears 

that if the test procedure changes supported by the automobile 

industry are adopted, the longstanding vehicle safety concerns of 

the manufacturers will be substantially resolved. However, I 

should explain that it is still up to EPA and NHTSA to 

independently analyze the vehicle safety and environmental 

implications of the proposed test procedure changes. 

Nonetheless, the design and in-use safety and performance of 

ORVR systems is ultimately the responsibility of the auto 

manufacturers. Apart from the test procedure changes, if needed, 

the possibility of holding the ORVR system design/safety dialogue 

discussed in the May 1993 notice still exists. 

10. NHTSA's Role in the Development of the May 27. 1993 Notice 

Since the January 1993 court decision regarding ORVR 

controls, EPA and NHTSA have resumed and continued close 

coordination regarding ORVR controls. EPA and NHTSA met in early 

April to discuss key issues pertaining to reopening the ORVR 

rulemaking process. On May 13, EPA sent NHTSA a copy for review. 

NHTSA returned comments in a letter dated May 17, 1993. These 

comments were incorporated into the notice. Both the draft 

version reviewed by NHTSA and the response letter are included in 

the public docket (IV-H-16 and IV-H-17, respectively). A NHTSA 

representative served as a panelist at the July 22 public 

hearing. There have been additional discussions and meeting with 

NHTSA staff on this subject. We will continue this close 

coordination with NHTSA in development of the final rule. 

RDSD:Connell:Passavant:2565 Plymouth Road:9/8/93:REFUELING 

Last Reviewed by Chet France:9/8/93:Control No. AL-93-3448 

Reviewed by DZinger:bjr:X27647:ANR-455:9/8/93:WP5.1:AL-3448