p.1 

OAR Box 1147 

Prepped by Ollie Stewart 

Document Number: 

200) IV-E-74 

Docket Number: 

A-87-11 

Printed 4/22/2008 2:42:58 PM Sheet 200 of 242 
P.2 

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

ANN ARBOR. MICHIGAN 48105 

OCT I 3 1988 

fr-fcl-H 

OFFICE OF 

AIR AND RADIATION 

MEMORANDUM 

SUBJECT: Observation of Stage II Refueling Events at Exxon 

Service Station, Washington, DC 

FROM: 

TO: 

THRU: 

Carolyn A. David, Chemical Engineer C^UA/yx>»A^^^ a ^ ^ 

Standards Development and Support Branch ' 

The Record 

John F. Anderson, Senior Project Manager 

Standards Development and Support Branch 

Chester J. France, Chief 

Standards Development and^Su Branch 

On February 16 and 17, 1988, John W. Mueller and I visited 

an Exxon Service Station, at 5030 Connecticut Avenue, 

Washington, DC, to observe refueling events with Stage II fuel 

dispensing systems. Dr. George S. Musser, of Exxon Research 

and Engineering, and Mr. Larry Hamilton, Station Manager, were 

both present to answer questions and show us the facilities and 

equipment. We collected information regarding service station 

facilities, station manager experience, and customer experience 

with Stage II. 

This Exxon station is located in a residential area, 

appears to be very well maintained, and operates 24 hours per 

day. Also, Stage II has been installed here since 1981; 

therefore, business comes primarily from repeat customers who 

have previously used Stage II nozzles. The station sells three 

grades of unleaded gasoline (regular-87 octane, plus-89 octane, 

supreme-93 octane) and has a throughput of approximately 3800 

gallons of fuel per day. There is one vent for all three 

underground fuel tanks, and no vent cap is in place. There is 

one full-serve and two self-serve islands (photo 1) where a 

total of 18 EMCO-Wheaton 3000 series nozzles are installed. 

These are current designs with coaxial, high-hang lines (photo 

2)- . , ^>ov\ 

lOVVr-f 
P.3 

Stage II operating instructions consist of a brief, 

finely-printed description painted on the nozzle cover, and 

which is commonly worn away with use (photo 3). These 

instructions warn against topping off and recommend a 

few-second delay after dispensing stops before replacing the 

nozzle in the holder. Clear, easy-to-read Stage II user 

instructions are otherwise not posted; however, there are 

directions for regular nozzle use. 

The station manager described his experiences regarding 

Stage II hardware and customer usage. Although he does not 

keep detailed maintenance records, Mr. Hamilton claimed he 

replaces four to five nozzle boots per month. These boots are 

occasionally torn or punctured by sheet metal screws in 

rear-fill vehicles (photos 4 and 5). He also mentioned there 

are problems with the vapor check and no-seal, no-flow device. 

The vapor check (within the nozzle) often tears; we were 

provided with a torn vapor sealing ring removed from a nozzle. 

EPA's concern here is that, if this valve is improperly sealed 

in one nozzle and fuel is being dispensed thru another nozzle, 

the vapor (from the vehicle fuel tank being filled) that is 

supposed to be forced into the underground tank may instead 

escape thru the improperly sealed nozzle. Mr. Hamilton said 

station personnel frequently show customers how to correctly 

latch the Stage II nozzle onto the vehicle fill neck, and if a 

customer tops off, they may need to drain any fuel collected in 

the nozzle boot (as a result of the top off) to prevent this 

fuel from potentially spilling onto the next customer. 

Interestingly, there are disposable plastic gloves available to 

the customers. They are worn during refueling and are quite 

popular with both men and women. 

While observing customer refueling events at Pump 1, we 

paid attention to how customers used the Stage II nozzles 

(correctly or incorrectly), the type and quantity of fuel 

dispensed, whether customers topped off, whether they observed 

the few-second, post-dispensing wait, and the size of any 

resulting spillage (Attachment 1). We recorded 49 refueling 

events at Pump 1. At Pumps 2 thru 6, we monitored the number 

of customers, Stage II usage, and spillage (see Attachment 2). 

Table 1 presents a summary of the data collected from Pump 

1. Of the 49 customers. observed at Pump 1, 35 percent topped 

off at least once. It is not known, however, how many were 

unable to top off (e.g., did not intend to fill up fuel tank 

for whatever reason) . Only one customer observed the 

post-dispensing, few-second wait period. 

Many people did not know how to correctly use the Stage II 

nozzles and welcomed assistance from station personnel. Most 

were not aware of the nozzle latch ring and how to correctly 

insert the nozzle and latch it onto their vehicle's fill neck. 
P.4 

Rather, customers used body weight to compress the bellows or 

pulled the bellows back with their hand. 

Spillage was affected by customer handling of the nozzle 

and the number of times the customer topped off. Although we 

did not get an exact count, we saw pre-fill and post-fill 

dripping occurring frequently - which some customers avoided by 

handling the nozzle carefully throughout the dispensing 

process. Top off also appeared to affect spillage. After one 

particular top off incident, the station attendant emptied the 

boot as a precautionary measure and got a three by four foot 

resulting spill. We emptied Pump 1 boots at two points during 

our monitoring; the resulting spills ranged from a few drops 

to 1.5 feet in diameter. These varying spillage sizes are 

illustrated in photos 6 thru 9. 

Scott Research Laboratories, Inc., has conducted a 

spillage survey designed to determine gasoline spillage 

magnitude (grams of hydrocarbons) from a measured equivalent 

spill diameter.* Scott technicians were trained to estimate 

spill diameters with acceptable repeatability and accuracy 

accounting for any variations in wetted areas. Although our 

repeatability and accuracy has not been determined, we have 

used our spill size estimates to quantify grams of hydrocarbons 

spilled. Using the curve Scott Research obtained from their 

data (Attachment 3), and our various spill size data (from 

Attachment 1) we estimated the grams of hydrocarbons associated 

with each spill (Table 2). The resulting values cannot be 

expressed in terms of grams of HC per gallon of fuel dispensed 

because we did not record spill size for all spills. 

"Investigation of Passenger Car . Refueling Losses: Second 

Year Program," Scott Project #2874, September 1, 1972, 

Scott Research Laboratories, Inc., 2600 Cajan Boulevard, 

San Bernardino, California, 92411. 
Table 1 

Staqe II Observations 

Washinqtons, DC 

P.5 

Total 

Refueling Events At Pump 1: 

Female: 

Male: 

49 

(16) 

(33) 

Customers Who Topped Off 

At Least Once: 

Female: 

Male: 

17 

(4) 

(13) 

Average Dispensed Fuel Volume: 

Customers Who Observed the 

Few Second Wait: 

10.02 gals 
P.6 

Table 2 

Estimated Grams of Hydrocarbons 

Associated with Observed Spillage 

Corresponding 

Date 

2/16/88 

2/16/88 

2/17/88 

2/17/88 

2/17/88 

2/17/88 

Time 

3:55pm 

3:30 

10:54am 

11:40am 

8:00am 

9:00am 

Pump 

1 

2 

1 

1 

3 

2 

Fuel* 

S 

R 

P 

S 

S 

R 

P 

Description 

Drained 

Boots & 

Nozzles 

Drain after 

Top Off 

Customer 

Spill 

Drained 

Boots & 

Nozzles 

OppositeSide Fill 

Drain After 

Top Off 

Spill Size 

10" 

3 drops 

l'x 2' 

5" 

l'x 1.5' 

6" 

2"x 3" 

1' 

10" 

3'x 4' 

Grams of HC 

5 

13 

2 

9 

2 

0 

7 

5 

97 

Fuel: S = unleaded supreme 

P = unleaded plus 

R = unleaded regular 
P.7 

Photos of Staqe II Refueling Observations* 

* The original set of photos are in Docket A-87-11, Environmental 

Protection Agency, Standards Development and Support Branch, 2565 

Plymouth, Ann Arbor, Michigan, 48105. Prints may be ordered by 

contacting Phil Carlson (313-668-4270) or Carolyn David 

(313-668-4278). There will be a printing charge. 
P.8 

Island 3 Island 2 Island 1 

Pump 6 Pump 5 

Full-Serve 

Fump 4 Pump 3 

Self-Serve 

Pump 2 Pump 1 

Self-Serve 

Photo 1: Exxon Service Station, 5030 Connecticut Avenue, 

Washington, DC 
P.9 

Photo 2: EMCO-Wheaton 3000 Series Nozzle 

Photo 3: Stage II Operating Instructions on Nozzle Cover 
P.10 

Photo 4: Torn Nozzle Cover 

Photo 5: Punctured Nozzle 3oct 
P.11 

Photo 6: Spillage From Nozzle Boot 

Photo 7: Spillage From Nozzle Boot 
P.12 

Photo 8: Spillage From Nozzle Boot 

Photo 9: Spillage From Nozzle Boot 
Attachment 1 

Pump 1 Refueling Observations 
P.14 

Refueling Observations at Pump 1: 

Washington, DC 

Exxon Station, 

Tuesday, February 16, 1988 

Time* 

pm Sex Fuel** Gallons 

2:15 

18 

30 

44 

57 

21 

29 

30 

35 

39 

43 

48 

55 

4:00 

4:08 

4:20 

4:26 

4:32 

41 

48 

52 

02 

06 

17 

21 

26 

F 

F 

F 

F 

M 

M 

M 

F 

F 

M 

M 

S 

P 

R 

R 

P 

P 

R 

P 

R 

S 

S 

Drained 

S 

R 

P 

M R 

F P 

M S 

M S 

F P 

F 

M 

M 

M 

M 

M 

M 

M 

9.25 

Boots 

10.587 

9.625 

8.704 

11.285 

11.02 

P 

P 

S 

P 

R 

S 

R 

P 

2 

4 

4 

4 

7 

888 

813 

352 

813 

078 

13.056 

19.245 

13.953 

Tops 

Offs 

N 

11 

6 

10 

12 

17 

4 

16 

9 

1 

16 

16 

052 

812 

759 

587 

603 

813 

168 

625 

012 

690 

058 

N 

1 

N 

2 

3 

N 

N 

N 

N 

N 

N 

Many 

N 

N 

N 

N 

N 

N 

N 

N 

N 

3 

16 

1 

Wait 

N 

N 

N 

N 

N 

N 

N 

N 

N 

N 

N 

N 

N 

N 

N 

N 

N 

N 

N 

N 

N 

N 

Comments 

Customer struggled with 

nozzle even after 

fuel flow began 

No Problems 

No drips 

Drips 

Postfill drips 

Drip 

10" spill 

3 drops 

1' x 2' spill 

Customer had 

difficulty getting 

nozzle in and started 

Twice/day customer 

** 

Time: Eastern Standard Time 

Fuel: S = unleaded supreme, $1.149, 93 octane 

P = unleaded plus, $1.039, 89 octane 

R = unleaded regular, $.989, 87 octane 
Refueling Observations at Pump 1: 

Washington, DC 

Exxon Station, 

Wednesday, February 17, 1988 

Time* 

am 

8 

8 

8 

:01 

:09 

.19 

Sex 

M 

M 

M 

Fuel** 

S 

P 

s 

Gallons 

12 

16 

4 

468 

348 

352 

Tops 

Offs 

7 

N 

N 

Wait 

N 

N 

N 

Comments 

8:29 

8:32 

8:39 

8:41 

8:49 

9:17 

9:26 

9:40 

9:52 

9:57 

10:00 

10:03 

10:31 

10:39 

F 

M 

F 

M 

F 

M 

M 

M 

M 

M 

M 

M 

F 

F 

S 

R 

P 

S 

R 

S 

P 

P 

P 

S 

S 

p 

s 

R 

6.696 

13.602 

4.592 

19.342 

2.023 

6.589 

4.813 

24.067 

10.879 

9.908 

8.704 

4.813 

13.161 

10.112 

N 

1 

N 

N 

N 

N 

N 

7-8 

1 

1 

N 

N 

3 

1 

N 

N 

N 

N 

N 

N 

N 

N 

N 

N 

N 

Y 

N 

N 

Couldn't work, had to 

be shown; switched 

grades thinking a 

different nozzle would 

work 

Top off looked 

unintentional 

Jaguar: quite a bit 

dripped from bootnozzle; vertical 

refueling 

Yanked nozzle out of 

rear-fill; no damage 

Used nozzle sideways 

because fill on far 

side of car; dribbled 

before and after, 

forgot to lift switch 

to start 

10:45 

10:54 

11:12 

11:29 

11:33 

11:40 

11:46 

11:53 

M 

M 

M 

M 

M 

Dr 

F 

M 

P 

S 

S 

R 

R 

ained 

S 

R 

P 

S 

R 

boot 

4.809 

15.662 

11.785 

7.785 

13.115 

s/nozzles: 

8.704 

1.012 

N 

2 

N 

1 

4 

N 

N 

N 

N 

N 

N 

N 

N 

N 

Left big spill: 

l'x 1 1/2' 

6" spill 

2" x 3" spill 

1' spill 
P.16 

Attachment 2 

Pumps 2 thru 6 Refueling Events 
P.17 

Refueling Events at Exxon Service Station 

Pumps 2 thru 6 

2:30 - 3:30 p.m. (2/16/88) 

Pump 2: 

7 Customers; 

Pump 3: 

6 Customers 

Attendant showed customer how to correctly insert and 

latch nozzle; manager also helped a customer; another 

customer had difficulty using nozzle; one customer cradled 

nozzle in arms and pushed forcefully to insert it and 

maintain compressed bellows. 

Pump 4: 

6 Customers 

Pump 5:* 

6 Customers 

Pump 6:* 

1 Customer 

3:30 - 4:30 p.m. (2/16/88) 

Pump 2:" 

5 Customers 

A customer topped off about 20 times; excessive postfill 

dripping; we obtained a 5-inch spill from boot upon 

draining. 

Pump 3: 

6 Customers 

* Note: Pump 5 and 6 are full-service pumps 
P.18 

Pump 4: 

4 Customers 

Pump 5: 

1 Customer 

Pump 6: 

5 Customers 

4:30 - 5:30 p.m. (2/16/88) 

Pump 2: 

9 Customers 

Pump 3: 

5 Customers 

A customer topped off about 10 times. 

Pump 4: 

4 Customers 

Pump 5: 

No Customers 

Pump 6: 

5 Customers 

8:00 - 9:00 a.m. (2/17/88) 

Pump 2: 

6 Customers 

One customer needed assistance operating the nozzle. 

Pump 3: 

7 Customers 

One customer tried stretching hose to other side of 

vehicle; had problems, and made a 10 inch spill. 
P.19 

Pump 4: 

2 Customers 

Pump 5: 

3 Customers 

Pump 6: 

2 Customers 

9:00 - 10:00 a.m. (2/17/88) 

Pump 2: 

3 Customers 

A customer did many top-offs and attendant drained a 3 by 

4 foot spill. 

Pump 3: 

2 Customers 

A customer had difficulty keeping the nozzle inserted and 

dispensing. 

Pump 4: 

2 Customers 

A customer had gas spilled on his hand from a leak in the 

boot base; manager took nozzle apart but saw no apparent 

problem; maybe top-off. 

Pump 5: 

1 Customer 

Pump 6: 

4 Customers 
10:00 - 11:00 a.m. (2/17/88) 

Pump 2: 

7 Customers 

Pump 3: 

4 Customers 

Pump 4: 

3 Customers 

Pump 5: 

2 Customers 

Pump 6: 

No Customers 
P.21 

Attachment 3 

Figure 4-2: Gasoline Spill Magnitude vs, 

Equivalent Spill Diameter for 

Typical Gasoline 

from 

"Investigation of Passenger Car 

Refueling Loss - Second-Year Program" 

Scott Project tt2874 

Scott Research Laboratories, Inc.. 

2600 Cajan Boulevard 

San Bernardino, California 92411 
§ 

o 1 

> 

o 

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> 

-4 

O 

200 h 

o 

OQ 

a. 

< 

S160 

> 

X 

to 

< 

a. 

J20 

UJ 

Q 

Zi 

z 

co 

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o_ 

c/> 

o 

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1,000 

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GASOLINE SPECIFIC 

GRAVITY = 0.7M0 

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< 

(9 

0 20 100 

INCHES 

M0 60 80 

EQUIVALENT SPILL DIAMETER, 

FIGURE 4-2 GASOLIIC SPILL mGNIlU E vs . EflUIVALENT SPILL DIAMETER 

FOR TYPICAL GASOLINE 

120