p.1 

OAR Box 1830 

Prepped by Ollie Stewart 

Document Number: 

147)IV-C-114 

Docket Number: 

A-87-11 

Printed 11/13/2008 7:20:59 AM Sheet 147 of 232 
P.2 

/ arm UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON. D.C. 20460 

APR 5 

THE AOMINISTRATOS 

Honorable John 0. Dingell 

Chairman 

Subcommittee on Oversight and Investigations 

Committee on Energy and Commerce 

U.S. House of Representatives 

Washington/ DC 20515 

Dear Mr. Chairman; 

This ia in response to your January 20, 1988 letter 

concerning the onboard vapor recovery and gasoline volatility 

control proposed rulemakings. In your letter you asked what 

the expected reductions would be from onboard controls by the 

year 199S and 2000 in each of the ozone nonattainment areas 

where Stage II controls have been or are being installed, or 

where a atate has committed in its State Implementation Plan 

(SIP) to require such controls/ assuming, at a minimum, a 

different leadtime than now proposed by EPA. You also 

requested the expected nationwide and Stage II nonattainment 

area benefits from volatility controls. In addition/ you 

expressed some concerns regarding contract work EPA is planning 

in regard to the safety of onboard systems. 

Aa a point of reference/ the areas which currently have 

Stage II installed or which are committed to it are California, 

New York City Metropolitan area (New York counties only), New 

Jersey, St. Louis (Missouri counties only) and Washington DC. 

EPA has excluded California in its emission projections, so 

only the four remaining areas will be discussed in this letter. 

With regard to your first question/ EPA has not completed 

its investigation of the effects that varied amounts of 

leadtime for onboard controls will have on emissions 

inventories. The amount of the inventory reduction in 1995 and 

2000 will depend on both the year in which a final rule is 

promulgated and the amount of leadtime given to manufacturers. 

We intend to perform such detailed studies as we continue our 

analyses of the leadtime issue. These studies will be able to 

incorporate the results of our leadtime analysis plus other 

analyses of issues relating to the timing and efficiency of 

controls. 
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Based on our current analysis we are able to estimate the 

incremental refueling emissions which would be captured by 

onboard systems in areas with Stage II controls (due to the 

higher in-use efficiency of onboard systems). EPA estimates 

the overall in-use efficiency of onboard systems to be 83 

percent versus an overall in-use efficiency of 48 to 66 percent 

for Stage II equipment (depending upon the level of 

enforcement). Therefore, onboard technology would control an 

additional 17 to 35 percent of uncontrolled refueling emissions 

in areas where Stage II is being implemented once onboard is 

fully implemented and incorporated in the vehicle fleet. 

Regarding your second question, Table 1 contains the 

effects of the proposed volatility controls on HC emission 

inventories for Stage II nonattainment areas as well as the 

entire nation. The inventories presented assume onboard 

controls are implemented beginning in 1990 and Stage II is in 

place only in Washington, DC. (If neither onboard nor Stage II 

controls were assumed, the inventories would be slightly higher 

but the percent reductions due to volatility controls would be 

essentially the same.) Volatility controls yield an 8.1 to 8.6 

percent reduction in the total nationwide HC emissions 

inventory, compared to an 8.1 to 9.7 percent reduction in each 

of the Stage II areas, it should be noted that for the four 

Stage II areas presented, EPA'S areas do not precisely match 

the areas where Stage ll is being implemented. For example, 

EPA*a analysis for St. Louis includes several surrounding 

counties in Illinois where Stage II is not required. This 

difference should not affect the percentage reduction 

calculations, however. 

Finally, you had several concerns regarding an EPA task 

order to conduct onboard safety related work through a 

contractor. EPA is preparing to conduct, through a contractor, 

a "Fuel System Comparative Risk Assessment11. 

In brief, the contract will be a comparative risk 

assessment of vehicle fuel/vapor control systems. It is 

intended to assess and compare the potential risks from the 

addition of onboard controls to those risks which may have 

arisen as a result of other recent changes in fuel systems. 

These represent some of the areas that the National Highway 

Traffic Safety Administration has suggested would be 

appropriate for EPA to Investigate in addressing the concerns 

about onboard safety. A failure modes and effects analysis 

will be conducted for nine slightly different fuel systems 

configurations, including three fuel systems with onboard 

control approaches incorporated. Each fuel system will be 

assessed ln terms of three phases with potential for safety 

problems (design, manufacture, and service) and under different 

accident scenarios* 
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voxatmty control proposed rulemakings; 

p; Sincerely, 

Lee M, Thomas 
MAY 11 '88 13"08 EPA P.5 

P.6 

2000 

Table 1 

Nationvide and Stage II Area HC Emissions Inventories-' 

1995 

Area 

Nationwide 

New Vork City Metro** 

New Jersey5 

Vineland-Millville 

Atlantic City 

St. Louis6 

Washington DC? 

(1000 tons/year^ 

No 

Control 

of RVP 

19504 

720.0 

12.2 

21.6 

207.2 

138.0 

EPA Gasoline 

Volatility 

Proposal-* 

17825 

652.7 

U.l 

19.5 

188.1 

126.4 

Reduction Due 

to EPA 

Proposal^ 

1679 (8.6) 

67.3 (9.3) 

l.l (9.0) 

2.1 (9.7) 

19.1 (9.2) 

11,6 (8.4) 

Nationwide 

New York City Metro-* 

New Jersey^ 

Vineland-Millville 

Atlantic City 

St. Louis6 

Washington DC7 

19947 

732.2 

12.1 

21.8 

213.1 

137.8 

18324 

666.8 

U.O 

19.8 

194,7 

126.7 

1623 (8.1) 

65.4 (8.9) 

l.l (9.1) 

2.0 (9.2) 

18.4 (8.6) 

U.l (8.1) 

1. The nationwide and city-specific inventories listed are taken from 

the data used to support the gasoline volatility control proposed 

rulemaking. 

2. EPA proposal limits summer gasoline volatility to 10.5 psi in 1989 

and 9.0 psl in 1992 in ASTM Class C areaa and proportional 

reductions from ASTM limits in other ASTM class areaa. 

3. Numbers in parentheaes are percent reduction in HC inventory from 

the "No Control of RV?" case. 

4. E?Afa analysis of the New York City Metropolitan area eontaina parts 

of Connecticut and New Jersey. 

5. The remaining parts of Nev Jersey are included in the Mew York City 

Metro area. 

6. EPA'a analysis of St. Louis contains several counties in Illinois. 

7. EPA's analysis of Washington DC contains parts of Virginia and 

Maryland.