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OAR Box 1818 

Prepped by Ollie Stewart 

Document Number: 

16) ll-C-13 

Docket Number: 

A-87-11 

Printed 11/6/2008 3:12:42 PM Sheet 16 of 79 
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4*\ SK 

\m** 7 

II -C-13 

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON. DC. 20460 

JAN 2 0 1987 

T H E AOMINISTRATOH 

l/i c . 

Honorable John D. Olngell 

Chairman, Subcommittee on 

Oversight and Investigations 

Committee on Energy and Commerce 

House of Representatives 

Washington, O.C. 20515 

Dear Mr. Chairman: 

<— 

'•-•"

 C 5 

In my December 9 response to your letter of September 15, 1986, I 

Informed you that responses to questions 5(a) and 7 would be forthcoming 

shortly. Enclosed are the EPA responses to those questions. 

If I can be of further assistance, please feel free to contact me. 

/^4^cer<eJ; 

^ 

Lee M. Thomas 

Enclosures 
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Onboard Fuel Recovery Credit* 

This portloa of EPA's response outlines Che general approach 

used Co esclaace the fuel consumption Impacts of onboard vapor 

recovery. Enclosed Is a thorough EPA analysis which details the 

calculation of the fuel economy effects associated vich onboard 

vapor control. The detailed analysis demonstrates that an onboard 

control system slightly reduces fuel consumption through the 

recovery of refueling vapors but also slightly Increases fuel 

consumption because of its added weight. The net effect of these 

two opposing impacts is a small fuel consumption benefit (or "net 

recovery credit") which acts to decrease the consumer's cost of 

onboard control. 

The major steps in calculating the fuel consumption Impacts 

of onboard controls are summarized below. This Is followed by a 

brief description of how the net recovery credit for onboard 

refueling controls was Incorporated in the gasoline marketing 

analysis. The calculation of the fuel consumption Impact of 

onboard controls is complicated but can be explained in three 

steps. 

The first step of the calculation (explained In pages 6 

through 16- of the detailed analysis) concerns an estimate of the 

gross reduction in the fuel consumed by a vehicle with onboard 

controls. The first of three factors that determine the gross 

fuel consumption reduction Is Che average total mass of hydrocarbons 

recovered over the life of the vehicle as a result of refueling 

controls. The recovered hydrocarbon mass is determined by multiplying the average refueling emission rate ( 5. S* grams HC/gallo'n 

of gasoline dispensed) by (1) the theoretical adsorption efficiency 

of an onboard system (973.) and (2) the average number of gallons 

of gasoline consumed by a vehicle in its lifetime. The second 

factor needed to calculate the gross fuel consumption reduction 

Is a conversion factor that transforms the recovered hydrocarbon 

mass to an equivalent volume of liquid gasoline. This conversion 

factor is obtained by dividing the energy value of the recovered 

hydrocarbons by the energy content of liquid gasoline. The third 

factor which affects the gross reduction of fuel consumed is the 

efficiency at which the recovered hydrocarbons are burned in the 

vehicle's engine. When multiplied together, these three factors 

determine the gross fuel consumption reduction. 

The second step of the calculation (explained in pages 2 

through 8 of the detailed analysis) involves the calculation of 

the "weight penalty" (the slight Increase in fuel consumption 

resulting from the added weight of the onboard system). The 

weight penalty depends on three factors. The first factor is the 

percent change in vehicle weight caused by the addition of an 

onboard control system. This percent change is obtained by 

dividing the control system weight (incremental to current and 

excess evaporative emission system weight) by the average 
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Encl./page I 

vehicle weight. The second factor needed Co calculate the weight 

penalty is a sensitivity factor which relates changes in fuel 

economy to changes in vehicle weight. When this sensitivity 

factor is multiplied by the percent change in vehicle weight, an 

estimate of the percent change in vehicle fuel economy is obtained. 

This percent change in fuel economy is then combined with the 

third weight penalty factor, the vehicle's lifetime fuel consumption, 

to obtain the overall increase in fuel consumption resulting from 

the additional weight of an onboard control system. 

The third and final step' of the caiculat 

pages 17 through 26 of the detailed analysis) 

latlon of the net fuel consumption reduction 

of this reduction from units of gallons of ga 

net present dollar value. The net fuel consu 

obtained by simply subtracting the weight pen 

fuel consumption reduction. The net present 

consumption reduction is obtained by apportio 

consumption reduction over each year of the v 

In turn, depends on the rate at which mileage 

annually and on vehicle fuel economy. Once t 

consumption reductions have been determined, 

by the price of gasoline (SO.98/gallon) and t 

discount factor for each year to account for 

money to determine the net present value of t 

the life of a vehicle with onboard control. 

Ion (explained in 

involves the calcuand the conversion 

sollne saved to a 

mptlon reduction is 

alty from the gross 

value of this fuel 

nlng Che total 

chicle life. This, 

is accumulated 

he annual net fuel 

they can be multiplied 

he appropriate 

the time value of 

he fuel saved throughout 
P.5 

QUESTION 5(a) 

Undtr the heading "Refueling Controls as a VOC Reduction 

Strategy," EPA staff states that Region 9 "is considering VOC 

reduction measures costing $2200-6600/Mg." Is that the REEP 

program that 1s of questionable legality? Please list those 

measures. 

RESPONSE TO QUESTION 5(a) 

The statement contained In the staff paper that "Region 9 

(Calif.) 1s considering VOC measures costing $2200-6600/Mg." Is 

unintentionally Inaccurate. EPA does not generally perform cost 

effectiveness analyses for control strategies needed to meet 

National Ambient A1r Quality Standards. However certain air 

quality control districts do. For Instance, 1n California, the 

South Coast A1r Quality Management District often performs cost 

effectiveness analyses which estimate the cost of certain control 

strategies on a per ton removed basis. The following 1s a 11st 

of some of the source catagoHes, and related cost effectiveness 

numbers for control strategies which are presently being Implemented 

1n that area. These cost estimates were developed by the District 

1n adopting their 1982 plans, and they are not a part of the REEP 

being considered in Region IX. 

Tactic Name Cost (1981 Dollars) 

(S/Ton VOC) 

B2 Industrial Maintenance Coating 2240 

DI Chemical Plant Valves 7800 

05 Pump 4 Compressor Leaks 4000 

62 Graphic Arts 5800 
P.6 

QUESTION 7 

...Please explain to what extent EPA agrees or disagrees with 

the comments and the conclusion [of the draft legal "brief" 

submitted on behalf of J1m Tozzi] that EPA has a legal duty to 

require that SIPs from ozone nonattainment areas provide for 

Implementation of Stage II controls. 

RESPONSE TO QUESTION 7 

As your letter notes, Mr. Tozzi's brief concludes that 

EPA has no choice but to require Stage II controls by regulation 

now for all ozone nonattainment areas. He bases this conclusion 

on the assumption that section 172 of the Act requires the SIPs 

for these areas to Include Stage II controls as a "reasonably 

available control measure" (RACM). 

EPA does not agree with Mr. Tozzi's Interpretation of the 

law. The Agency believes that Congress1 Intent, as expressed 

In section 202(a)(6) of the Clean Air Act, 1s that EPA should 

make a careful, reasoned choice, on the merits, between onboard 

and Stage II controls. Thus, Mr. Tozzl's arguments that Stage 

II must be considered RACM and that Congress assumed Stage II 

controls were RACM, are Inconsistent with section 202(a)(6) 

and would render 1t a nullity. EPA does not believe Congress 

would have Intended such a result. 

Nor does EPA believe that a legal duty arises from Its 

previous statements about Stage II. Although some older EPA 

Information and SIP policy documents show that Stage II was 

considered technologically feasible, EPA has never required 

that a State Include Stage II as RACM 1n Its ozone nonattainment 

SIP as a condition for SIP approval, or otherwise defined 

Stage II to be RACM 1n any SIP or other rulemaking. This 1s 

true even 1n the District of Columbia example cited by Mr. 

Tozzi. 

As noted earlier, section 202(a)(6) requires EPA to examine 

control of gas marketing emissions. In response to that mandate, 

the EPA has undertaken an exhaustive review of this very Important 

Issue. The suggestion that EPA "ambivalence" on Stage II has 

delayed achievement of the ozone standard and created Inequities 

among states understates both the complexity of the gasoline 

marketing Issue and the magnitude of the ozone nonattainment 

problem. Even 1f EPA had required all ozone nonattainment 

areas to Impose Stage II as RACM, that by Itself would have 

brought few if any of those areas Into timely attainment. 

Attainment of the ozone standard will 1n most nonattainment 

areas require difficult choices and the Imposition of controls 

on a number of source categories 1n addition to gasoline marketing. 

Moreover, I do not believe that EPA's actions have produced 

Inequities among the States. Some jurisdictions have chosen 

to Implement Stage II as a means to attain the ozone standard 

and avoid potential Clean Air Act sanctions. Naturally, EPA 

has reacted to steps taken to achieve attainment with encouragement rather than silence.